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Message-ID: <CAA8EJppvwQNwgWhiExJM1HdttVb_sih9M2qbuouB79YqReOWkw@mail.gmail.com>
Date: Thu, 7 Mar 2024 09:26:48 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Md Sadre Alam <quic_mdalam@...cinc.com>
Cc: andersson@...nel.org, konrad.dybcio@...aro.org, broonie@...nel.org, 
	robh@...nel.org, krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org, 
	miquel.raynal@...tlin.com, richard@....at, vigneshr@...com, 
	manivannan.sadhasivam@...aro.org, linux-arm-msm@...r.kernel.org, 
	linux-spi@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-mtd@...ts.infradead.org, 
	quic_varada@...cinc.com, quic_srichara@...cinc.com
Subject: Re: [PATCH v3 2/5] drivers: mtd: nand: Add qpic_common API file

On Thu, 7 Mar 2024 at 06:19, Md Sadre Alam <quic_mdalam@...cinc.com> wrote:
>
> Add qpic_common.c file which hold all the common
> qpic APIs which will be used by both qpic raw nand
> driver and qpic spi nand driver.
>
> Co-developed-by: Sricharan Ramabadhran <quic_srichara@...cinc.com>
> Signed-off-by: Sricharan Ramabadhran <quic_srichara@...cinc.com>
> Co-developed-by: Varadarajan Narayanan <quic_varada@...cinc.com>
> Signed-off-by: Varadarajan Narayanan <quic_varada@...cinc.com>
> Signed-off-by: Md Sadre Alam <quic_mdalam@...cinc.com>
> ---
> Change in [v3]
>
> * Added original copy right
>
> * Removed all EXPORT_SYMBOL()
>
> * Made this common api file more generic
>
> * Added qcom_ prefix to all api in this file
>
> * Removed devm_kfree and added kfree
>
> * Moved to_qcom_nand_controller() to raw nand driver
>   since it was only used by raw nand driver, so not needed
>   as common
>
> * Added kernel doc for all api
>
> * made reverse tree of variable declaration in
>   prep_adm_dma_desc() function
>
> * Added if(!ret) condition in prep_adm_dma_desc()
>   function
>
> * Initialized slave_conf as 0 while declaration
>
> Change in [v2]
>
> * Posted initial support for common api file
>
> Change in [v1]
>
> * Posted as RFC patch for design review
>
>  drivers/mtd/nand/Makefile            |    1 +
>  drivers/mtd/nand/qpic_common.c       |  781 ++++++++++++++
>  drivers/mtd/nand/raw/qcom_nandc.c    | 1440 +++-----------------------
>  include/linux/mtd/nand-qpic-common.h |  486 +++++++++
>  4 files changed, 1403 insertions(+), 1305 deletions(-)
>  create mode 100644 drivers/mtd/nand/qpic_common.c
>  create mode 100644 include/linux/mtd/nand-qpic-common.h
>
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index 19e1291ac4d5..131707a41293 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -12,3 +12,4 @@ nandcore-$(CONFIG_MTD_NAND_ECC) += ecc.o
>  nandcore-$(CONFIG_MTD_NAND_ECC_SW_HAMMING) += ecc-sw-hamming.o
>  nandcore-$(CONFIG_MTD_NAND_ECC_SW_BCH) += ecc-sw-bch.o
>  nandcore-$(CONFIG_MTD_NAND_ECC_MXIC) += ecc-mxic.o
> +obj-y += qpic_common.o

So, this object file will be built-in into all kernels that have NAND
enabled? Clearly this is not a way to go.

> diff --git a/drivers/mtd/nand/qpic_common.c b/drivers/mtd/nand/qpic_common.c
> new file mode 100644
> index 000000000000..11e322fdd706
> --- /dev/null
> +++ b/drivers/mtd/nand/qpic_common.c
> @@ -0,0 +1,781 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2016, The Linux Foundation. All rights reserved.
> + */
> +#include <linux/mtd/nand-qpic-common.h>
> +
> +/*
> + * qcom_free_bam_transaction:  Frees the BAM transaction memory
> + */

This is not a kerneldoc comment. Please take a look at the documentation first.

> +void qcom_free_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +       kfree(bam_txn);
> +}
> +
> +/*
> + * qcom_clear_read_regs:       reset the register read buffer
> + *                             for next NAND operation
> + */
> +void qcom_clear_read_regs(struct qcom_nand_controller *nandc)
> +{
> +       nandc->reg_read_pos = 0;
> +       qcom_nandc_read_buffer_sync(nandc, false);
> +}
> +
> +/*
> + * qcom_qpic_bam_dma_done:     Callback for DMA descriptor completion
> + *
> + * @data:                      data
> + */
> +void qcom_qpic_bam_dma_done(void *data)
> +{
> +       struct bam_transaction *bam_txn = data;
> +
> +       /*
> +        * In case of data transfer with NAND, 2 callbacks will be generated.
> +        * One for command channel and another one for data channel.
> +        * If current transaction has data descriptors
> +        * (i.e. wait_second_completion is true), then set this to false
> +        * and wait for second DMA descriptor completion.
> +        */
> +       if (bam_txn->wait_second_completion)
> +               bam_txn->wait_second_completion = false;
> +       else
> +               complete(&bam_txn->txn_done);
> +}
> +
> +/*
> + * qcom_nandc_read_buffer_sync:        Check for dma sync for cpu or device
> + *
> + * @is_cpu:                    cpu or Device
> + */
> +void qcom_nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
> +                                bool is_cpu)
> +{
> +       if (!nandc->props->is_bam)
> +               return;
> +
> +       if (is_cpu)
> +               dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
> +                                       MAX_REG_RD *
> +                                       sizeof(*nandc->reg_read_buf),
> +                                       DMA_FROM_DEVICE);
> +       else
> +               dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
> +                                          MAX_REG_RD *
> +                                          sizeof(*nandc->reg_read_buf),
> +                                          DMA_FROM_DEVICE);
> +}
> +
> +/*
> + * qcom_offset_to_nandc_reg:   Get the actual offset for qpic register
> + * @ offset:                   register offset
> + */
> +__le32 *qcom_offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> +{
> +       switch (offset) {
> +       case NAND_FLASH_CMD:
> +               return &regs->cmd;
> +       case NAND_ADDR0:
> +               return &regs->addr0;
> +       case NAND_ADDR1:
> +               return &regs->addr1;
> +       case NAND_FLASH_CHIP_SELECT:
> +               return &regs->chip_sel;
> +       case NAND_EXEC_CMD:
> +               return &regs->exec;
> +       case NAND_FLASH_STATUS:
> +               return &regs->clrflashstatus;
> +       case NAND_DEV0_CFG0:
> +               return &regs->cfg0;
> +       case NAND_DEV0_CFG1:
> +               return &regs->cfg1;
> +       case NAND_DEV0_ECC_CFG:
> +               return &regs->ecc_bch_cfg;
> +       case NAND_READ_STATUS:
> +               return &regs->clrreadstatus;
> +       case NAND_DEV_CMD1:
> +               return &regs->cmd1;
> +       case NAND_DEV_CMD1_RESTORE:
> +               return &regs->orig_cmd1;
> +       case NAND_DEV_CMD_VLD:
> +               return &regs->vld;
> +       case NAND_DEV_CMD_VLD_RESTORE:
> +               return &regs->orig_vld;
> +       case NAND_EBI2_ECC_BUF_CFG:
> +               return &regs->ecc_buf_cfg;
> +       case NAND_READ_LOCATION_0:
> +               return &regs->read_location0;
> +       case NAND_READ_LOCATION_1:
> +               return &regs->read_location1;
> +       case NAND_READ_LOCATION_2:
> +               return &regs->read_location2;
> +       case NAND_READ_LOCATION_3:
> +               return &regs->read_location3;
> +       case NAND_READ_LOCATION_LAST_CW_0:
> +               return &regs->read_location_last0;
> +       case NAND_READ_LOCATION_LAST_CW_1:
> +               return &regs->read_location_last1;
> +       case NAND_READ_LOCATION_LAST_CW_2:
> +               return &regs->read_location_last2;
> +       case NAND_READ_LOCATION_LAST_CW_3:
> +               return &regs->read_location_last3;
> +       default:
> +               return NULL;
> +       }
> +}
> +
> +/*
> + * qcom_prep_adm_dma_desc:     Prepare descriptor for adma
> + * @read:                      read or write
> + * @reg_off:                   offset within the controller's data buffer
> + * @vaddr:                     virtual address of the buffer we want to write to
> + * @size:                      adm dma transaction size in bytes
> + * @flow_control:              flow controller
> + */
> +int qcom_prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> +                          int reg_off, const void *vaddr, int size,
> +                            bool flow_control)
> +{
> +       struct qcom_adm_peripheral_config periph_conf = {};
> +       struct dma_async_tx_descriptor *dma_desc;
> +       struct dma_slave_config slave_conf = {0};
> +       enum dma_transfer_direction dir_eng;
> +       struct scatterlist *sgl;
> +       struct desc_info *desc;
> +       int ret;
> +
> +       desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +       if (!desc)
> +               return -ENOMEM;
> +
> +       sgl = &desc->adm_sgl;
> +
> +       sg_init_one(sgl, vaddr, size);
> +
> +       if (read) {
> +               dir_eng = DMA_DEV_TO_MEM;
> +               desc->dir = DMA_FROM_DEVICE;
> +       } else {
> +               dir_eng = DMA_MEM_TO_DEV;
> +               desc->dir = DMA_TO_DEVICE;
> +       }
> +
> +       ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
> +       if (!ret) {
> +               ret = -ENOMEM;
> +               goto err;
> +       }
> +
> +       slave_conf.device_fc = flow_control;
> +       if (read) {
> +               slave_conf.src_maxburst = 16;
> +               slave_conf.src_addr = nandc->base_dma + reg_off;
> +               if (nandc->data_crci) {
> +                       periph_conf.crci = nandc->data_crci;
> +                       slave_conf.peripheral_config = &periph_conf;
> +                       slave_conf.peripheral_size = sizeof(periph_conf);
> +               }
> +       } else {
> +               slave_conf.dst_maxburst = 16;
> +               slave_conf.dst_addr = nandc->base_dma + reg_off;
> +               if (nandc->cmd_crci) {
> +                       periph_conf.crci = nandc->cmd_crci;
> +                       slave_conf.peripheral_config = &periph_conf;
> +                       slave_conf.peripheral_size = sizeof(periph_conf);
> +               }
> +       }
> +
> +       ret = dmaengine_slave_config(nandc->chan, &slave_conf);
> +       if (ret) {
> +               dev_err(nandc->dev, "failed to configure dma channel\n");
> +               goto err;
> +       }
> +
> +       dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
> +       if (!dma_desc) {
> +               dev_err(nandc->dev, "failed to prepare desc\n");
> +               ret = -EINVAL;
> +               goto err;
> +       }
> +
> +       desc->dma_desc = dma_desc;
> +
> +       list_add_tail(&desc->node, &nandc->desc_list);
> +
> +       return 0;
> +err:
> +       kfree(desc);
> +
> +       return ret;
> +}
> +
> +/*
> + * qcom_submit_descs:  submit descriptor cmd/data
> + */
> +int qcom_submit_descs(struct qcom_nand_controller *nandc)
> +{
> +       struct desc_info *desc, *n;
> +       dma_cookie_t cookie = 0;
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +       int ret = 0;
> +
> +       if (nandc->props->is_bam) {
> +               if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
> +                       ret = qcom_prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
> +                       if (ret)
> +                               goto err_unmap_free_desc;
> +               }
> +
> +               if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
> +                       ret = qcom_prepare_bam_async_desc(nandc, nandc->tx_chan,
> +                                                         DMA_PREP_INTERRUPT);
> +                       if (ret)
> +                               goto err_unmap_free_desc;
> +               }
> +
> +               if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
> +                       ret = qcom_prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +                                                         DMA_PREP_CMD);
> +                       if (ret)
> +                               goto err_unmap_free_desc;
> +               }
> +       }
> +
> +       list_for_each_entry(desc, &nandc->desc_list, node)
> +               cookie = dmaengine_submit(desc->dma_desc);
> +
> +       if (nandc->props->is_bam) {
> +               bam_txn->last_cmd_desc->callback = qcom_qpic_bam_dma_done;
> +               bam_txn->last_cmd_desc->callback_param = bam_txn;
> +               if (bam_txn->last_data_desc) {
> +                       bam_txn->last_data_desc->callback = qcom_qpic_bam_dma_done;
> +                       bam_txn->last_data_desc->callback_param = bam_txn;
> +                       bam_txn->wait_second_completion = true;
> +               }
> +
> +               dma_async_issue_pending(nandc->tx_chan);
> +               dma_async_issue_pending(nandc->rx_chan);
> +               dma_async_issue_pending(nandc->cmd_chan);
> +
> +               if (!wait_for_completion_timeout(&bam_txn->txn_done,
> +                                                QPIC_NAND_COMPLETION_TIMEOUT))
> +                       ret = -ETIMEDOUT;
> +       } else {
> +               if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
> +                       ret = -ETIMEDOUT;
> +       }
> +
> +err_unmap_free_desc:
> +       /*
> +        * Unmap the dma sg_list and free the desc allocated by both
> +        * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
> +        */
> +       list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
> +               list_del(&desc->node);
> +
> +               if (nandc->props->is_bam)
> +                       dma_unmap_sg(nandc->dev, desc->bam_sgl,
> +                                    desc->sgl_cnt, desc->dir);
> +               else
> +                       dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
> +                                    desc->dir);
> +
> +               kfree(desc);
> +       }
> +
> +       return ret;
> +}
> +
> +/*
> + * qcom_prepare_bam_async_desc:        Maps the scatter gather list for DMA transfer
> + *                             and forms the DMA descriptor for BAM.This
> + *                             descriptor will be added in the NAND DMA
> + *                             descriptor queue which will be submitted to DMA
> + *                             engine
> + * @chan:                      dma channel
> + * @flag:                      flags to control DMA descriptor preparation
> + */
> +int qcom_prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> +                               struct dma_chan *chan,
> +                                 unsigned long flags)
> +{
> +       struct desc_info *desc;
> +       struct scatterlist *sgl;
> +       unsigned int sgl_cnt;
> +       int ret;
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +       enum dma_transfer_direction dir_eng;
> +       struct dma_async_tx_descriptor *dma_desc;
> +
> +       desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> +       if (!desc)
> +               return -ENOMEM;
> +
> +       if (chan == nandc->cmd_chan) {
> +               sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
> +               sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
> +               bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
> +               dir_eng = DMA_MEM_TO_DEV;
> +               desc->dir = DMA_TO_DEVICE;
> +       } else if (chan == nandc->tx_chan) {
> +               sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
> +               sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
> +               bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
> +               dir_eng = DMA_MEM_TO_DEV;
> +               desc->dir = DMA_TO_DEVICE;
> +       } else {
> +               sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
> +               sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
> +               bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
> +               dir_eng = DMA_DEV_TO_MEM;
> +               desc->dir = DMA_FROM_DEVICE;
> +       }
> +
> +       sg_mark_end(sgl + sgl_cnt - 1);
> +       ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +       if (ret == 0) {
> +               dev_err(nandc->dev, "failure in mapping desc\n");
> +               kfree(desc);
> +               return -ENOMEM;
> +       }
> +
> +       desc->sgl_cnt = sgl_cnt;
> +       desc->bam_sgl = sgl;
> +
> +       dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
> +                                          flags);
> +
> +       if (!dma_desc) {
> +               dev_err(nandc->dev, "failure in prep desc\n");
> +               dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> +               kfree(desc);
> +               return -EINVAL;
> +       }
> +
> +       desc->dma_desc = dma_desc;
> +
> +       /* update last data/command descriptor */
> +       if (chan == nandc->cmd_chan)
> +               bam_txn->last_cmd_desc = dma_desc;
> +       else
> +               bam_txn->last_data_desc = dma_desc;
> +
> +       list_add_tail(&desc->node, &nandc->desc_list);
> +
> +       return 0;
> +}
> +
> +/*
> + * qcom_prep_bam_dma_desc_cmd: Prepares the command descriptor for BAM DMA
> + *                             which will be used for NAND register reads and
> + *                             writes.
> + * @read:                      read/write type
> + * @reg_off:                   offset within the controller's data buffer
> + * @vaddr:                     virtual address of the buffer we want to write to
> + * @size:                      DMA transaction size in bytes
> + * @flags:                     offset within the controller's data buffer
> + */
> +int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> +                              int reg_off, const void *vaddr,
> +                                int size, unsigned int flags)
> +{
> +       int bam_ce_size;
> +       int i, ret;
> +       struct bam_cmd_element *bam_ce_buffer;
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +       bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> +
> +       /* fill the command desc */
> +       for (i = 0; i < size; i++) {
> +               if (read)
> +                       bam_prep_ce(&bam_ce_buffer[i],
> +                                   nandc_reg_phys(nandc, reg_off + 4 * i),
> +                                   BAM_READ_COMMAND,
> +                                   reg_buf_dma_addr(nandc,
> +                                                    (__le32 *)vaddr + i));
> +               else
> +                       bam_prep_ce_le32(&bam_ce_buffer[i],
> +                                        nandc_reg_phys(nandc, reg_off + 4 * i),
> +                                        BAM_WRITE_COMMAND,
> +                                        *((__le32 *)vaddr + i));
> +       }
> +
> +       bam_txn->bam_ce_pos += size;
> +
> +       /* use the separate sgl after this command */
> +       if (flags & NAND_BAM_NEXT_SGL) {
> +               bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> +               bam_ce_size = (bam_txn->bam_ce_pos -
> +                               bam_txn->bam_ce_start) *
> +                               sizeof(struct bam_cmd_element);
> +               sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> +                          bam_ce_buffer, bam_ce_size);
> +               bam_txn->cmd_sgl_pos++;
> +               bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> +
> +               if (flags & NAND_BAM_NWD) {
> +                       ret = qcom_prepare_bam_async_desc(nandc, nandc->cmd_chan,
> +                                                         DMA_PREP_FENCE |
> +                                                    DMA_PREP_CMD);
> +                       if (ret)
> +                               return ret;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +/*
> + * qcom_prep_bam_dma_desc_data:        Prepares the data descriptor for BAM DMA which
> + *                             will be used for NAND data reads and writes.
> + * @read:                      read/write type
> + * @vaddr:                     virtual address of the buffer we want to write to
> + * @size:                      DMA transaction size in bytes
> + * @flags:                     flags to control DMA descriptor preparation
> + */
> +int qcom_prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> +                               const void *vaddr,
> +                                 int size, unsigned int flags)
> +{
> +       int ret;
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +       if (read) {
> +               sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
> +                          vaddr, size);
> +               bam_txn->rx_sgl_pos++;
> +       } else {
> +               sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
> +                          vaddr, size);
> +               bam_txn->tx_sgl_pos++;
> +
> +               /*
> +                * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> +                * is not set, form the DMA descriptor
> +                */
> +               if (!(flags & NAND_BAM_NO_EOT)) {
> +                       ret = qcom_prepare_bam_async_desc(nandc, nandc->tx_chan,
> +                                                         DMA_PREP_INTERRUPT);
> +                       if (ret)
> +                               return ret;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
> +/*
> + * qcom_read_reg_dma:  prepares a descriptor to read a given number of
> + *                     contiguous registers to the reg_read_buf pointer
> + *
> + * @first:             offset of the first register in the contiguous block
> + * @num_regs:          number of registers to read
> + * @flags:             flags to control DMA descriptor preparation
> + */
> +int qcom_read_reg_dma(struct qcom_nand_controller *nandc, int first,
> +                     int num_regs, unsigned int flags)
> +{
> +       bool flow_control = false;
> +       void *vaddr;
> +
> +       vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> +       nandc->reg_read_pos += num_regs;
> +
> +       if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> +               first = dev_cmd_reg_addr(nandc, first);
> +
> +       if (nandc->props->is_bam)
> +               return qcom_prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
> +                                            num_regs, flags);
> +
> +       if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> +               flow_control = true;
> +
> +       return qcom_prep_adm_dma_desc(nandc, true, first, vaddr,
> +                                num_regs * sizeof(u32), flow_control);
> +}
> +
> +/*
> + * qcom_write_reg_dma: prepares a descriptor to write a given number of
> + *                     contiguous registers
> + *
> + * @first:             offset of the first register in the contiguous block
> + * @num_regs:          number of registers to write
> + * @flags:             flags to control DMA descriptor preparation
> + */
> +int qcom_write_reg_dma(struct qcom_nand_controller *nandc, int first,
> +                      int num_regs, unsigned int flags)
> +{
> +       bool flow_control = false;
> +       struct nandc_regs *regs = nandc->regs;
> +       void *vaddr;
> +
> +       vaddr = qcom_offset_to_nandc_reg(regs, first);
> +
> +       if (first == NAND_ERASED_CW_DETECT_CFG) {
> +               if (flags & NAND_ERASED_CW_SET)
> +                       vaddr = &regs->erased_cw_detect_cfg_set;
> +               else
> +                       vaddr = &regs->erased_cw_detect_cfg_clr;
> +       }
> +
> +       if (first == NAND_EXEC_CMD)
> +               flags |= NAND_BAM_NWD;
> +
> +       if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> +               first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
> +
> +       if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> +               first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
> +
> +       if (nandc->props->is_bam)
> +               return qcom_prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
> +                                            num_regs, flags);
> +
> +       if (first == NAND_FLASH_CMD)
> +               flow_control = true;
> +
> +       return qcom_prep_adm_dma_desc(nandc, false, first, vaddr,
> +                                num_regs * sizeof(u32), flow_control);
> +}
> +
> +/*
> + * qcom_read_data_dma: prepares a DMA descriptor to transfer data from the
> + *                     controller's internal buffer to the buffer 'vaddr'
> + *
> + * @reg_off:           offset within the controller's data buffer
> + * @vaddr:             virtual address of the buffer we want to write to
> + * @size:              DMA transaction size in bytes
> + * @flags:             flags to control DMA descriptor preparation
> + */
> +int qcom_read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +                      const u8 *vaddr, int size, unsigned int flags)
> +{
> +       if (nandc->props->is_bam)
> +               return qcom_prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
> +
> +       return qcom_prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
> +}
> +
> +/*
> + * qcom_write_data_dma:        prepares a DMA descriptor to transfer data from
> + *                     'vaddr' to the controller's internal buffer
> + *
> + * @reg_off:           offset within the controller's data buffer
> + * @vaddr:             virtual address of the buffer we want to read from
> + * @size:              DMA transaction size in bytes
> + * @flags:             flags to control DMA descriptor preparation
> + */
> +int qcom_write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +                       const u8 *vaddr, int size, unsigned int flags)
> +{
> +       if (nandc->props->is_bam)
> +               return qcom_prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
> +
> +       return qcom_prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
> +}
> +
> +/*
> + * qcom_alloc_bam_transaction: Allocates and Initializes the BAM transaction
> + */
> +struct bam_transaction *
> +qcom_alloc_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +       struct bam_transaction *bam_txn;
> +       size_t bam_txn_size;
> +       unsigned int num_cw = nandc->max_cwperpage;
> +       void *bam_txn_buf;
> +
> +       bam_txn_size =
> +               sizeof(*bam_txn) + num_cw *
> +               ((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
> +               (sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
> +               (sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
> +
> +       bam_txn_buf = kzalloc(bam_txn_size, GFP_KERNEL);
> +       if (!bam_txn_buf)
> +               return NULL;
> +
> +       bam_txn = bam_txn_buf;
> +       bam_txn_buf += sizeof(*bam_txn);
> +
> +       bam_txn->bam_ce = bam_txn_buf;
> +       bam_txn_buf +=
> +               sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
> +
> +       bam_txn->cmd_sgl = bam_txn_buf;
> +       bam_txn_buf +=
> +               sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
> +
> +       bam_txn->data_sgl = bam_txn_buf;
> +
> +       init_completion(&bam_txn->txn_done);
> +
> +       return bam_txn;
> +}
> +
> +/*
> + * qcom_clear_bam_transaction: Clears the BAM transaction indexes
> + */
> +void qcom_clear_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> +       struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> +       if (!nandc->props->is_bam)
> +               return;
> +
> +       bam_txn->bam_ce_pos = 0;
> +       bam_txn->bam_ce_start = 0;
> +       bam_txn->cmd_sgl_pos = 0;
> +       bam_txn->cmd_sgl_start = 0;
> +       bam_txn->tx_sgl_pos = 0;
> +       bam_txn->tx_sgl_start = 0;
> +       bam_txn->rx_sgl_pos = 0;
> +       bam_txn->rx_sgl_start = 0;
> +       bam_txn->last_data_desc = NULL;
> +       bam_txn->wait_second_completion = false;
> +
> +       sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> +                     QPIC_PER_CW_CMD_SGL);
> +       sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
> +                     QPIC_PER_CW_DATA_SGL);
> +
> +       reinit_completion(&bam_txn->txn_done);
> +}
> +
> +/*
> + * qcom_nandc_unalloc: unallocate memory allocated for controller
> + */
> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> +{
> +       if (nandc->props->is_bam) {
> +               if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
> +                       dma_unmap_single(nandc->dev, nandc->reg_read_dma,
> +                                        MAX_REG_RD *
> +                                        sizeof(*nandc->reg_read_buf),
> +                                        DMA_FROM_DEVICE);
> +
> +               if (nandc->tx_chan)
> +                       dma_release_channel(nandc->tx_chan);
> +
> +               if (nandc->rx_chan)
> +                       dma_release_channel(nandc->rx_chan);
> +
> +               if (nandc->cmd_chan)
> +                       dma_release_channel(nandc->cmd_chan);
> +       } else {
> +               if (nandc->chan)
> +                       dma_release_channel(nandc->chan);
> +       }
> +}
> +
> +/*
> + * qcom_nandc_alloc:   Allocate memory for nand controller
> + */
> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
> +{
> +       int ret;
> +
> +       ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
> +       if (ret) {
> +               dev_err(nandc->dev, "failed to set DMA mask\n");
> +               return ret;
> +       }
> +
> +       /*
> +        * we use the internal buffer for reading ONFI params, reading small
> +        * data like ID and status, and preforming read-copy-write operations
> +        * when writing to a codeword partially. 532 is the maximum possible
> +        * size of a codeword for our nand controller
> +        */
> +       nandc->buf_size = 532;
> +
> +       nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
> +       if (!nandc->data_buffer)
> +               return -ENOMEM;
> +
> +       nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
> +       if (!nandc->regs)
> +               return -ENOMEM;
> +
> +       nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
> +                                          sizeof(*nandc->reg_read_buf),
> +                                          GFP_KERNEL);
> +       if (!nandc->reg_read_buf)
> +               return -ENOMEM;
> +
> +       if (nandc->props->is_bam) {
> +               nandc->reg_read_dma =
> +                       dma_map_single(nandc->dev, nandc->reg_read_buf,
> +                                      MAX_REG_RD *
> +                                      sizeof(*nandc->reg_read_buf),
> +                                      DMA_FROM_DEVICE);
> +               if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
> +                       dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
> +                       return -EIO;
> +               }
> +
> +               nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
> +               if (IS_ERR(nandc->tx_chan)) {
> +                       ret = PTR_ERR(nandc->tx_chan);
> +                       nandc->tx_chan = NULL;
> +                       dev_err_probe(nandc->dev, ret,
> +                                     "tx DMA channel request failed\n");
> +                       goto unalloc;
> +               }
> +
> +               nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
> +               if (IS_ERR(nandc->rx_chan)) {
> +                       ret = PTR_ERR(nandc->rx_chan);
> +                       nandc->rx_chan = NULL;
> +                       dev_err_probe(nandc->dev, ret,
> +                                     "rx DMA channel request failed\n");
> +                       goto unalloc;
> +               }
> +
> +               nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
> +               if (IS_ERR(nandc->cmd_chan)) {
> +                       ret = PTR_ERR(nandc->cmd_chan);
> +                       nandc->cmd_chan = NULL;
> +                       dev_err_probe(nandc->dev, ret,
> +                                     "cmd DMA channel request failed\n");
> +                       goto unalloc;
> +               }
> +
> +               /*
> +                * Initially allocate BAM transaction to read ONFI param page.
> +                * After detecting all the devices, this BAM transaction will
> +                * be freed and the next BAM transaction will be allocated with
> +                * maximum codeword size
> +                */
> +               nandc->max_cwperpage = 1;
> +               nandc->bam_txn = qcom_alloc_bam_transaction(nandc);
> +               if (!nandc->bam_txn) {
> +                       dev_err(nandc->dev,
> +                               "failed to allocate bam transaction\n");
> +                       ret = -ENOMEM;
> +                       goto unalloc;
> +               }
> +       } else {
> +               nandc->chan = dma_request_chan(nandc->dev, "rxtx");
> +               if (IS_ERR(nandc->chan)) {
> +                       ret = PTR_ERR(nandc->chan);
> +                       nandc->chan = NULL;
> +                       dev_err_probe(nandc->dev, ret,
> +                                     "rxtx DMA channel request failed\n");
> +                       return ret;
> +               }
> +       }
> +
> +       INIT_LIST_HEAD(&nandc->desc_list);
> +       INIT_LIST_HEAD(&nandc->host_list);
> +
> +       return 0;
> +unalloc:
> +       qcom_nandc_unalloc(nandc);
> +       return ret;
> +}
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index b079605c84d3..d4faabc8244f 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2,186 +2,7 @@
>  /*
>   * Copyright (c) 2016, The Linux Foundation. All rights reserved.
>   */
> -#include <linux/bitops.h>
> -#include <linux/clk.h>
> -#include <linux/delay.h>
> -#include <linux/dmaengine.h>
> -#include <linux/dma-mapping.h>
> -#include <linux/dma/qcom_adm.h>
> -#include <linux/dma/qcom_bam_dma.h>
> -#include <linux/module.h>
> -#include <linux/mtd/partitions.h>
> -#include <linux/mtd/rawnand.h>
> -#include <linux/of.h>
> -#include <linux/platform_device.h>
> -#include <linux/slab.h>
> -
> -/* NANDc reg offsets */
> -#define        NAND_FLASH_CMD                  0x00
> -#define        NAND_ADDR0                      0x04
> -#define        NAND_ADDR1                      0x08
> -#define        NAND_FLASH_CHIP_SELECT          0x0c
> -#define        NAND_EXEC_CMD                   0x10
> -#define        NAND_FLASH_STATUS               0x14
> -#define        NAND_BUFFER_STATUS              0x18
> -#define        NAND_DEV0_CFG0                  0x20
> -#define        NAND_DEV0_CFG1                  0x24
> -#define        NAND_DEV0_ECC_CFG               0x28
> -#define        NAND_AUTO_STATUS_EN             0x2c
> -#define        NAND_DEV1_CFG0                  0x30
> -#define        NAND_DEV1_CFG1                  0x34
> -#define        NAND_READ_ID                    0x40
> -#define        NAND_READ_STATUS                0x44
> -#define        NAND_DEV_CMD0                   0xa0
> -#define        NAND_DEV_CMD1                   0xa4
> -#define        NAND_DEV_CMD2                   0xa8
> -#define        NAND_DEV_CMD_VLD                0xac
> -#define        SFLASHC_BURST_CFG               0xe0
> -#define        NAND_ERASED_CW_DETECT_CFG       0xe8
> -#define        NAND_ERASED_CW_DETECT_STATUS    0xec
> -#define        NAND_EBI2_ECC_BUF_CFG           0xf0
> -#define        FLASH_BUF_ACC                   0x100
> -
> -#define        NAND_CTRL                       0xf00
> -#define        NAND_VERSION                    0xf08
> -#define        NAND_READ_LOCATION_0            0xf20
> -#define        NAND_READ_LOCATION_1            0xf24
> -#define        NAND_READ_LOCATION_2            0xf28
> -#define        NAND_READ_LOCATION_3            0xf2c
> -#define        NAND_READ_LOCATION_LAST_CW_0    0xf40
> -#define        NAND_READ_LOCATION_LAST_CW_1    0xf44
> -#define        NAND_READ_LOCATION_LAST_CW_2    0xf48
> -#define        NAND_READ_LOCATION_LAST_CW_3    0xf4c
> -
> -/* dummy register offsets, used by write_reg_dma */
> -#define        NAND_DEV_CMD1_RESTORE           0xdead
> -#define        NAND_DEV_CMD_VLD_RESTORE        0xbeef
> -
> -/* NAND_FLASH_CMD bits */
> -#define        PAGE_ACC                        BIT(4)
> -#define        LAST_PAGE                       BIT(5)
> -
> -/* NAND_FLASH_CHIP_SELECT bits */
> -#define        NAND_DEV_SEL                    0
> -#define        DM_EN                           BIT(2)
> -
> -/* NAND_FLASH_STATUS bits */
> -#define        FS_OP_ERR                       BIT(4)
> -#define        FS_READY_BSY_N                  BIT(5)
> -#define        FS_MPU_ERR                      BIT(8)
> -#define        FS_DEVICE_STS_ERR               BIT(16)
> -#define        FS_DEVICE_WP                    BIT(23)
> -
> -/* NAND_BUFFER_STATUS bits */
> -#define        BS_UNCORRECTABLE_BIT            BIT(8)
> -#define        BS_CORRECTABLE_ERR_MSK          0x1f
> -
> -/* NAND_DEVn_CFG0 bits */
> -#define        DISABLE_STATUS_AFTER_WRITE      4
> -#define        CW_PER_PAGE                     6
> -#define        UD_SIZE_BYTES                   9
> -#define        UD_SIZE_BYTES_MASK              GENMASK(18, 9)
> -#define        ECC_PARITY_SIZE_BYTES_RS        19
> -#define        SPARE_SIZE_BYTES                23
> -#define        SPARE_SIZE_BYTES_MASK           GENMASK(26, 23)
> -#define        NUM_ADDR_CYCLES                 27
> -#define        STATUS_BFR_READ                 30
> -#define        SET_RD_MODE_AFTER_STATUS        31
> -
> -/* NAND_DEVn_CFG0 bits */
> -#define        DEV0_CFG1_ECC_DISABLE           0
> -#define        WIDE_FLASH                      1
> -#define        NAND_RECOVERY_CYCLES            2
> -#define        CS_ACTIVE_BSY                   5
> -#define        BAD_BLOCK_BYTE_NUM              6
> -#define        BAD_BLOCK_IN_SPARE_AREA         16
> -#define        WR_RD_BSY_GAP                   17
> -#define        ENABLE_BCH_ECC                  27
> -
> -/* NAND_DEV0_ECC_CFG bits */
> -#define        ECC_CFG_ECC_DISABLE             0
> -#define        ECC_SW_RESET                    1
> -#define        ECC_MODE                        4
> -#define        ECC_PARITY_SIZE_BYTES_BCH       8
> -#define        ECC_NUM_DATA_BYTES              16
> -#define        ECC_NUM_DATA_BYTES_MASK         GENMASK(25, 16)
> -#define        ECC_FORCE_CLK_OPEN              30
> -
> -/* NAND_DEV_CMD1 bits */
> -#define        READ_ADDR                       0
> -
> -/* NAND_DEV_CMD_VLD bits */
> -#define        READ_START_VLD                  BIT(0)
> -#define        READ_STOP_VLD                   BIT(1)
> -#define        WRITE_START_VLD                 BIT(2)
> -#define        ERASE_START_VLD                 BIT(3)
> -#define        SEQ_READ_START_VLD              BIT(4)
> -
> -/* NAND_EBI2_ECC_BUF_CFG bits */
> -#define        NUM_STEPS                       0
> -
> -/* NAND_ERASED_CW_DETECT_CFG bits */
> -#define        ERASED_CW_ECC_MASK              1
> -#define        AUTO_DETECT_RES                 0
> -#define        MASK_ECC                        BIT(ERASED_CW_ECC_MASK)
> -#define        RESET_ERASED_DET                BIT(AUTO_DETECT_RES)
> -#define        ACTIVE_ERASED_DET               (0 << AUTO_DETECT_RES)
> -#define        CLR_ERASED_PAGE_DET             (RESET_ERASED_DET | MASK_ECC)
> -#define        SET_ERASED_PAGE_DET             (ACTIVE_ERASED_DET | MASK_ECC)
> -
> -/* NAND_ERASED_CW_DETECT_STATUS bits */
> -#define        PAGE_ALL_ERASED                 BIT(7)
> -#define        CODEWORD_ALL_ERASED             BIT(6)
> -#define        PAGE_ERASED                     BIT(5)
> -#define        CODEWORD_ERASED                 BIT(4)
> -#define        ERASED_PAGE                     (PAGE_ALL_ERASED | PAGE_ERASED)
> -#define        ERASED_CW                       (CODEWORD_ALL_ERASED | CODEWORD_ERASED)
> -
> -/* NAND_READ_LOCATION_n bits */
> -#define READ_LOCATION_OFFSET           0
> -#define READ_LOCATION_SIZE             16
> -#define READ_LOCATION_LAST             31
> -
> -/* Version Mask */
> -#define        NAND_VERSION_MAJOR_MASK         0xf0000000
> -#define        NAND_VERSION_MAJOR_SHIFT        28
> -#define        NAND_VERSION_MINOR_MASK         0x0fff0000
> -#define        NAND_VERSION_MINOR_SHIFT        16
> -
> -/* NAND OP_CMDs */
> -#define        OP_PAGE_READ                    0x2
> -#define        OP_PAGE_READ_WITH_ECC           0x3
> -#define        OP_PAGE_READ_WITH_ECC_SPARE     0x4
> -#define        OP_PAGE_READ_ONFI_READ          0x5
> -#define        OP_PROGRAM_PAGE                 0x6
> -#define        OP_PAGE_PROGRAM_WITH_ECC        0x7
> -#define        OP_PROGRAM_PAGE_SPARE           0x9
> -#define        OP_BLOCK_ERASE                  0xa
> -#define        OP_CHECK_STATUS                 0xc
> -#define        OP_FETCH_ID                     0xb
> -#define        OP_RESET_DEVICE                 0xd
> -
> -/* Default Value for NAND_DEV_CMD_VLD */
> -#define NAND_DEV_CMD_VLD_VAL           (READ_START_VLD | WRITE_START_VLD | \
> -                                        ERASE_START_VLD | SEQ_READ_START_VLD)
> -
> -/* NAND_CTRL bits */
> -#define        BAM_MODE_EN                     BIT(0)
> -
> -/*
> - * the NAND controller performs reads/writes with ECC in 516 byte chunks.
> - * the driver calls the chunks 'step' or 'codeword' interchangeably
> - */
> -#define        NANDC_STEP_SIZE                 512
> -
> -/*
> - * the largest page size we support is 8K, this will have 16 steps/codewords
> - * of 512 bytes each
> - */
> -#define        MAX_NUM_STEPS                   (SZ_8K / NANDC_STEP_SIZE)
> -
> -/* we read at most 3 registers per codeword scan */
> -#define        MAX_REG_RD                      (3 * MAX_NUM_STEPS)
> +#include <linux/mtd/nand-qpic-common.h>
>
>  /* ECC modes supported by the controller */
>  #define        ECC_NONE        BIT(0)
> @@ -200,247 +21,6 @@ nandc_set_reg(chip, reg,                   \
>               ((cw_offset) << READ_LOCATION_OFFSET) |           \
>               ((read_size) << READ_LOCATION_SIZE) |                     \
>               ((is_last_read_loc) << READ_LOCATION_LAST))
> -/*
> - * Returns the actual register address for all NAND_DEV_ registers
> - * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> - */
> -#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))
> -
> -/* Returns the NAND register physical address */
> -#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
> -
> -/* Returns the dma address for reg read buffer */
> -#define reg_buf_dma_addr(chip, vaddr) \
> -       ((chip)->reg_read_dma + \
> -       ((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
> -
> -#define QPIC_PER_CW_CMD_ELEMENTS       32
> -#define QPIC_PER_CW_CMD_SGL            32
> -#define QPIC_PER_CW_DATA_SGL           8
> -
> -#define QPIC_NAND_COMPLETION_TIMEOUT   msecs_to_jiffies(2000)
> -
> -/*
> - * Flags used in DMA descriptor preparation helper functions
> - * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
> - */
> -/* Don't set the EOT in current tx BAM sgl */
> -#define NAND_BAM_NO_EOT                        BIT(0)
> -/* Set the NWD flag in current BAM sgl */
> -#define NAND_BAM_NWD                   BIT(1)
> -/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
> -#define NAND_BAM_NEXT_SGL              BIT(2)
> -/*
> - * Erased codeword status is being used two times in single transfer so this
> - * flag will determine the current value of erased codeword status register
> - */
> -#define NAND_ERASED_CW_SET             BIT(4)
> -
> -#define MAX_ADDRESS_CYCLE              5
> -
> -/*
> - * This data type corresponds to the BAM transaction which will be used for all
> - * NAND transfers.
> - * @bam_ce - the array of BAM command elements
> - * @cmd_sgl - sgl for NAND BAM command pipe
> - * @data_sgl - sgl for NAND BAM consumer/producer pipe
> - * @last_data_desc - last DMA desc in data channel (tx/rx).
> - * @last_cmd_desc - last DMA desc in command channel.
> - * @txn_done - completion for NAND transfer.
> - * @bam_ce_pos - the index in bam_ce which is available for next sgl
> - * @bam_ce_start - the index in bam_ce which marks the start position ce
> - *                for current sgl. It will be used for size calculation
> - *                for current sgl
> - * @cmd_sgl_pos - current index in command sgl.
> - * @cmd_sgl_start - start index in command sgl.
> - * @tx_sgl_pos - current index in data sgl for tx.
> - * @tx_sgl_start - start index in data sgl for tx.
> - * @rx_sgl_pos - current index in data sgl for rx.
> - * @rx_sgl_start - start index in data sgl for rx.
> - * @wait_second_completion - wait for second DMA desc completion before making
> - *                          the NAND transfer completion.
> - */
> -struct bam_transaction {
> -       struct bam_cmd_element *bam_ce;
> -       struct scatterlist *cmd_sgl;
> -       struct scatterlist *data_sgl;
> -       struct dma_async_tx_descriptor *last_data_desc;
> -       struct dma_async_tx_descriptor *last_cmd_desc;
> -       struct completion txn_done;
> -       u32 bam_ce_pos;
> -       u32 bam_ce_start;
> -       u32 cmd_sgl_pos;
> -       u32 cmd_sgl_start;
> -       u32 tx_sgl_pos;
> -       u32 tx_sgl_start;
> -       u32 rx_sgl_pos;
> -       u32 rx_sgl_start;
> -       bool wait_second_completion;
> -};
> -
> -/*
> - * This data type corresponds to the nand dma descriptor
> - * @dma_desc - low level DMA engine descriptor
> - * @list - list for desc_info
> - *
> - * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
> - *           ADM
> - * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
> - * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
> - * @dir - DMA transfer direction
> - */
> -struct desc_info {
> -       struct dma_async_tx_descriptor *dma_desc;
> -       struct list_head node;
> -
> -       union {
> -               struct scatterlist adm_sgl;
> -               struct {
> -                       struct scatterlist *bam_sgl;
> -                       int sgl_cnt;
> -               };
> -       };
> -       enum dma_data_direction dir;
> -};
> -
> -/*
> - * holds the current register values that we want to write. acts as a contiguous
> - * chunk of memory which we use to write the controller registers through DMA.
> - */
> -struct nandc_regs {
> -       __le32 cmd;
> -       __le32 addr0;
> -       __le32 addr1;
> -       __le32 chip_sel;
> -       __le32 exec;
> -
> -       __le32 cfg0;
> -       __le32 cfg1;
> -       __le32 ecc_bch_cfg;
> -
> -       __le32 clrflashstatus;
> -       __le32 clrreadstatus;
> -
> -       __le32 cmd1;
> -       __le32 vld;
> -
> -       __le32 orig_cmd1;
> -       __le32 orig_vld;
> -
> -       __le32 ecc_buf_cfg;
> -       __le32 read_location0;
> -       __le32 read_location1;
> -       __le32 read_location2;
> -       __le32 read_location3;
> -       __le32 read_location_last0;
> -       __le32 read_location_last1;
> -       __le32 read_location_last2;
> -       __le32 read_location_last3;
> -
> -       __le32 erased_cw_detect_cfg_clr;
> -       __le32 erased_cw_detect_cfg_set;
> -};
> -
> -/*
> - * NAND controller data struct
> - *
> - * @dev:                       parent device
> - *
> - * @base:                      MMIO base
> - *
> - * @core_clk:                  controller clock
> - * @aon_clk:                   another controller clock
> - *
> - * @regs:                      a contiguous chunk of memory for DMA register
> - *                             writes. contains the register values to be
> - *                             written to controller
> - *
> - * @props:                     properties of current NAND controller,
> - *                             initialized via DT match data
> - *
> - * @controller:                        base controller structure
> - * @host_list:                 list containing all the chips attached to the
> - *                             controller
> - *
> - * @chan:                      dma channel
> - * @cmd_crci:                  ADM DMA CRCI for command flow control
> - * @data_crci:                 ADM DMA CRCI for data flow control
> - *
> - * @desc_list:                 DMA descriptor list (list of desc_infos)
> - *
> - * @data_buffer:               our local DMA buffer for page read/writes,
> - *                             used when we can't use the buffer provided
> - *                             by upper layers directly
> - * @reg_read_buf:              local buffer for reading back registers via DMA
> - *
> - * @base_phys:                 physical base address of controller registers
> - * @base_dma:                  dma base address of controller registers
> - * @reg_read_dma:              contains dma address for register read buffer
> - *
> - * @buf_size/count/start:      markers for chip->legacy.read_buf/write_buf
> - *                             functions
> - * @max_cwperpage:             maximum QPIC codewords required. calculated
> - *                             from all connected NAND devices pagesize
> - *
> - * @reg_read_pos:              marker for data read in reg_read_buf
> - *
> - * @cmd1/vld:                  some fixed controller register values
> - *
> - * @exec_opwrite:              flag to select correct number of code word
> - *                             while reading status
> - */
> -struct qcom_nand_controller {
> -       struct device *dev;
> -
> -       void __iomem *base;
> -
> -       struct clk *core_clk;
> -       struct clk *aon_clk;
> -
> -       struct nandc_regs *regs;
> -       struct bam_transaction *bam_txn;
> -
> -       const struct qcom_nandc_props *props;
> -
> -       struct nand_controller controller;
> -       struct list_head host_list;
> -
> -       union {
> -               /* will be used only by QPIC for BAM DMA */
> -               struct {
> -                       struct dma_chan *tx_chan;
> -                       struct dma_chan *rx_chan;
> -                       struct dma_chan *cmd_chan;
> -               };
> -
> -               /* will be used only by EBI2 for ADM DMA */
> -               struct {
> -                       struct dma_chan *chan;
> -                       unsigned int cmd_crci;
> -                       unsigned int data_crci;
> -               };
> -       };
> -
> -       struct list_head desc_list;
> -
> -       u8              *data_buffer;
> -       __le32          *reg_read_buf;
> -
> -       phys_addr_t base_phys;
> -       dma_addr_t base_dma;
> -       dma_addr_t reg_read_dma;
> -
> -       int             buf_size;
> -       int             buf_count;
> -       int             buf_start;
> -       unsigned int    max_cwperpage;
> -
> -       int reg_read_pos;
> -
> -       u32 cmd1, vld;
> -       bool exec_opwrite;
> -};
> -
>  /*
>   * NAND special boot partitions
>   *
> @@ -544,113 +124,24 @@ struct qcom_nand_host {
>         bool bch_enabled;
>  };
>
> -/*
> - * This data type corresponds to the NAND controller properties which varies
> - * among different NAND controllers.
> - * @ecc_modes - ecc mode for NAND
> - * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
> - * @is_bam - whether NAND controller is using BAM
> - * @is_qpic - whether NAND CTRL is part of qpic IP
> - * @qpic_v2 - flag to indicate QPIC IP version 2
> - * @use_codeword_fixup - whether NAND has different layout for boot partitions
> - */
> -struct qcom_nandc_props {
> -       u32 ecc_modes;
> -       u32 dev_cmd_reg_start;
> -       bool is_bam;
> -       bool is_qpic;
> -       bool qpic_v2;
> -       bool use_codeword_fixup;
> -};
> -
> -/* Frees the BAM transaction memory */
> -static void free_bam_transaction(struct qcom_nand_controller *nandc)
> -{
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -       devm_kfree(nandc->dev, bam_txn);
> -}
> -
> -/* Allocates and Initializes the BAM transaction */
> -static struct bam_transaction *
> -alloc_bam_transaction(struct qcom_nand_controller *nandc)
> +struct qcom_nand_controller *
> +get_qcom_nand_controller(struct nand_chip *chip)
>  {
> -       struct bam_transaction *bam_txn;
> -       size_t bam_txn_size;
> -       unsigned int num_cw = nandc->max_cwperpage;
> -       void *bam_txn_buf;
> -
> -       bam_txn_size =
> -               sizeof(*bam_txn) + num_cw *
> -               ((sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS) +
> -               (sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL) +
> -               (sizeof(*bam_txn->data_sgl) * QPIC_PER_CW_DATA_SGL));
> -
> -       bam_txn_buf = devm_kzalloc(nandc->dev, bam_txn_size, GFP_KERNEL);
> -       if (!bam_txn_buf)
> -               return NULL;
> -
> -       bam_txn = bam_txn_buf;
> -       bam_txn_buf += sizeof(*bam_txn);
> -
> -       bam_txn->bam_ce = bam_txn_buf;
> -       bam_txn_buf +=
> -               sizeof(*bam_txn->bam_ce) * QPIC_PER_CW_CMD_ELEMENTS * num_cw;
> -
> -       bam_txn->cmd_sgl = bam_txn_buf;
> -       bam_txn_buf +=
> -               sizeof(*bam_txn->cmd_sgl) * QPIC_PER_CW_CMD_SGL * num_cw;
> -
> -       bam_txn->data_sgl = bam_txn_buf;
> -
> -       init_completion(&bam_txn->txn_done);
> -
> -       return bam_txn;
> +       return container_of(chip->controller, struct qcom_nand_controller,
> +                           controller);
>  }
>
> -/* Clears the BAM transaction indexes */
> -static void clear_bam_transaction(struct qcom_nand_controller *nandc)
> +static void nandc_set_reg(struct nand_chip *chip, int offset,
> +                         u32 val)
>  {
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -       if (!nandc->props->is_bam)
> -               return;
> -
> -       bam_txn->bam_ce_pos = 0;
> -       bam_txn->bam_ce_start = 0;
> -       bam_txn->cmd_sgl_pos = 0;
> -       bam_txn->cmd_sgl_start = 0;
> -       bam_txn->tx_sgl_pos = 0;
> -       bam_txn->tx_sgl_start = 0;
> -       bam_txn->rx_sgl_pos = 0;
> -       bam_txn->rx_sgl_start = 0;
> -       bam_txn->last_data_desc = NULL;
> -       bam_txn->wait_second_completion = false;
> -
> -       sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> -                     QPIC_PER_CW_CMD_SGL);
> -       sg_init_table(bam_txn->data_sgl, nandc->max_cwperpage *
> -                     QPIC_PER_CW_DATA_SGL);
> -
> -       reinit_completion(&bam_txn->txn_done);
> -}
> +       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +       struct nandc_regs *regs = nandc->regs;
> +       __le32 *reg;
>
> -/* Callback for DMA descriptor completion */
> -static void qpic_bam_dma_done(void *data)
> -{
> -       struct bam_transaction *bam_txn = data;
> +       reg = qcom_offset_to_nandc_reg(regs, offset);
>
> -       /*
> -        * In case of data transfer with NAND, 2 callbacks will be generated.
> -        * One for command channel and another one for data channel.
> -        * If current transaction has data descriptors
> -        * (i.e. wait_second_completion is true), then set this to false
> -        * and wait for second DMA descriptor completion.
> -        */
> -       if (bam_txn->wait_second_completion)
> -               bam_txn->wait_second_completion = false;
> -       else
> -               complete(&bam_txn->txn_done);
> +       if (reg)
> +               *reg = cpu_to_le32(val);
>  }
>
>  static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
> @@ -658,13 +149,6 @@ static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
>         return container_of(chip, struct qcom_nand_host, chip);
>  }
>
> -static inline struct qcom_nand_controller *
> -get_qcom_nand_controller(struct nand_chip *chip)
> -{
> -       return container_of(chip->controller, struct qcom_nand_controller,
> -                           controller);
> -}
> -
>  static inline u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
>  {
>         return ioread32(nandc->base + offset);
> @@ -676,91 +160,6 @@ static inline void nandc_write(struct qcom_nand_controller *nandc, int offset,
>         iowrite32(val, nandc->base + offset);
>  }
>
> -static inline void nandc_read_buffer_sync(struct qcom_nand_controller *nandc,
> -                                         bool is_cpu)
> -{
> -       if (!nandc->props->is_bam)
> -               return;
> -
> -       if (is_cpu)
> -               dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma,
> -                                       MAX_REG_RD *
> -                                       sizeof(*nandc->reg_read_buf),
> -                                       DMA_FROM_DEVICE);
> -       else
> -               dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma,
> -                                          MAX_REG_RD *
> -                                          sizeof(*nandc->reg_read_buf),
> -                                          DMA_FROM_DEVICE);
> -}
> -
> -static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> -{
> -       switch (offset) {
> -       case NAND_FLASH_CMD:
> -               return &regs->cmd;
> -       case NAND_ADDR0:
> -               return &regs->addr0;
> -       case NAND_ADDR1:
> -               return &regs->addr1;
> -       case NAND_FLASH_CHIP_SELECT:
> -               return &regs->chip_sel;
> -       case NAND_EXEC_CMD:
> -               return &regs->exec;
> -       case NAND_FLASH_STATUS:
> -               return &regs->clrflashstatus;
> -       case NAND_DEV0_CFG0:
> -               return &regs->cfg0;
> -       case NAND_DEV0_CFG1:
> -               return &regs->cfg1;
> -       case NAND_DEV0_ECC_CFG:
> -               return &regs->ecc_bch_cfg;
> -       case NAND_READ_STATUS:
> -               return &regs->clrreadstatus;
> -       case NAND_DEV_CMD1:
> -               return &regs->cmd1;
> -       case NAND_DEV_CMD1_RESTORE:
> -               return &regs->orig_cmd1;
> -       case NAND_DEV_CMD_VLD:
> -               return &regs->vld;
> -       case NAND_DEV_CMD_VLD_RESTORE:
> -               return &regs->orig_vld;
> -       case NAND_EBI2_ECC_BUF_CFG:
> -               return &regs->ecc_buf_cfg;
> -       case NAND_READ_LOCATION_0:
> -               return &regs->read_location0;
> -       case NAND_READ_LOCATION_1:
> -               return &regs->read_location1;
> -       case NAND_READ_LOCATION_2:
> -               return &regs->read_location2;
> -       case NAND_READ_LOCATION_3:
> -               return &regs->read_location3;
> -       case NAND_READ_LOCATION_LAST_CW_0:
> -               return &regs->read_location_last0;
> -       case NAND_READ_LOCATION_LAST_CW_1:
> -               return &regs->read_location_last1;
> -       case NAND_READ_LOCATION_LAST_CW_2:
> -               return &regs->read_location_last2;
> -       case NAND_READ_LOCATION_LAST_CW_3:
> -               return &regs->read_location_last3;
> -       default:
> -               return NULL;
> -       }
> -}
> -
> -static void nandc_set_reg(struct nand_chip *chip, int offset,
> -                         u32 val)
> -{
> -       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> -       struct nandc_regs *regs = nandc->regs;
> -       __le32 *reg;
> -
> -       reg = offset_to_nandc_reg(regs, offset);
> -
> -       if (reg)
> -               *reg = cpu_to_le32(val);
> -}
> -
>  /* Helper to check the code word, whether it is last cw or not */
>  static bool qcom_nandc_is_last_cw(struct nand_ecc_ctrl *ecc, int cw)
>  {
> @@ -852,383 +251,6 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read, i
>                                    host->cw_data : host->cw_size, 1);
>  }
>
> -/*
> - * Maps the scatter gather list for DMA transfer and forms the DMA descriptor
> - * for BAM. This descriptor will be added in the NAND DMA descriptor queue
> - * which will be submitted to DMA engine.
> - */
> -static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> -                                 struct dma_chan *chan,
> -                                 unsigned long flags)
> -{
> -       struct desc_info *desc;
> -       struct scatterlist *sgl;
> -       unsigned int sgl_cnt;
> -       int ret;
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -       enum dma_transfer_direction dir_eng;
> -       struct dma_async_tx_descriptor *dma_desc;
> -
> -       desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> -       if (!desc)
> -               return -ENOMEM;
> -
> -       if (chan == nandc->cmd_chan) {
> -               sgl = &bam_txn->cmd_sgl[bam_txn->cmd_sgl_start];
> -               sgl_cnt = bam_txn->cmd_sgl_pos - bam_txn->cmd_sgl_start;
> -               bam_txn->cmd_sgl_start = bam_txn->cmd_sgl_pos;
> -               dir_eng = DMA_MEM_TO_DEV;
> -               desc->dir = DMA_TO_DEVICE;
> -       } else if (chan == nandc->tx_chan) {
> -               sgl = &bam_txn->data_sgl[bam_txn->tx_sgl_start];
> -               sgl_cnt = bam_txn->tx_sgl_pos - bam_txn->tx_sgl_start;
> -               bam_txn->tx_sgl_start = bam_txn->tx_sgl_pos;
> -               dir_eng = DMA_MEM_TO_DEV;
> -               desc->dir = DMA_TO_DEVICE;
> -       } else {
> -               sgl = &bam_txn->data_sgl[bam_txn->rx_sgl_start];
> -               sgl_cnt = bam_txn->rx_sgl_pos - bam_txn->rx_sgl_start;
> -               bam_txn->rx_sgl_start = bam_txn->rx_sgl_pos;
> -               dir_eng = DMA_DEV_TO_MEM;
> -               desc->dir = DMA_FROM_DEVICE;
> -       }
> -
> -       sg_mark_end(sgl + sgl_cnt - 1);
> -       ret = dma_map_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> -       if (ret == 0) {
> -               dev_err(nandc->dev, "failure in mapping desc\n");
> -               kfree(desc);
> -               return -ENOMEM;
> -       }
> -
> -       desc->sgl_cnt = sgl_cnt;
> -       desc->bam_sgl = sgl;
> -
> -       dma_desc = dmaengine_prep_slave_sg(chan, sgl, sgl_cnt, dir_eng,
> -                                          flags);
> -
> -       if (!dma_desc) {
> -               dev_err(nandc->dev, "failure in prep desc\n");
> -               dma_unmap_sg(nandc->dev, sgl, sgl_cnt, desc->dir);
> -               kfree(desc);
> -               return -EINVAL;
> -       }
> -
> -       desc->dma_desc = dma_desc;
> -
> -       /* update last data/command descriptor */
> -       if (chan == nandc->cmd_chan)
> -               bam_txn->last_cmd_desc = dma_desc;
> -       else
> -               bam_txn->last_data_desc = dma_desc;
> -
> -       list_add_tail(&desc->node, &nandc->desc_list);
> -
> -       return 0;
> -}
> -
> -/*
> - * Prepares the command descriptor for BAM DMA which will be used for NAND
> - * register reads and writes. The command descriptor requires the command
> - * to be formed in command element type so this function uses the command
> - * element from bam transaction ce array and fills the same with required
> - * data. A single SGL can contain multiple command elements so
> - * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
> - * after the current command element.
> - */
> -static int prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> -                                int reg_off, const void *vaddr,
> -                                int size, unsigned int flags)
> -{
> -       int bam_ce_size;
> -       int i, ret;
> -       struct bam_cmd_element *bam_ce_buffer;
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -       bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> -
> -       /* fill the command desc */
> -       for (i = 0; i < size; i++) {
> -               if (read)
> -                       bam_prep_ce(&bam_ce_buffer[i],
> -                                   nandc_reg_phys(nandc, reg_off + 4 * i),
> -                                   BAM_READ_COMMAND,
> -                                   reg_buf_dma_addr(nandc,
> -                                                    (__le32 *)vaddr + i));
> -               else
> -                       bam_prep_ce_le32(&bam_ce_buffer[i],
> -                                        nandc_reg_phys(nandc, reg_off + 4 * i),
> -                                        BAM_WRITE_COMMAND,
> -                                        *((__le32 *)vaddr + i));
> -       }
> -
> -       bam_txn->bam_ce_pos += size;
> -
> -       /* use the separate sgl after this command */
> -       if (flags & NAND_BAM_NEXT_SGL) {
> -               bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> -               bam_ce_size = (bam_txn->bam_ce_pos -
> -                               bam_txn->bam_ce_start) *
> -                               sizeof(struct bam_cmd_element);
> -               sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> -                          bam_ce_buffer, bam_ce_size);
> -               bam_txn->cmd_sgl_pos++;
> -               bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> -
> -               if (flags & NAND_BAM_NWD) {
> -                       ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> -                                                    DMA_PREP_FENCE |
> -                                                    DMA_PREP_CMD);
> -                       if (ret)
> -                               return ret;
> -               }
> -       }
> -
> -       return 0;
> -}
> -
> -/*
> - * Prepares the data descriptor for BAM DMA which will be used for NAND
> - * data reads and writes.
> - */
> -static int prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> -                                 const void *vaddr,
> -                                 int size, unsigned int flags)
> -{
> -       int ret;
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -
> -       if (read) {
> -               sg_set_buf(&bam_txn->data_sgl[bam_txn->rx_sgl_pos],
> -                          vaddr, size);
> -               bam_txn->rx_sgl_pos++;
> -       } else {
> -               sg_set_buf(&bam_txn->data_sgl[bam_txn->tx_sgl_pos],
> -                          vaddr, size);
> -               bam_txn->tx_sgl_pos++;
> -
> -               /*
> -                * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> -                * is not set, form the DMA descriptor
> -                */
> -               if (!(flags & NAND_BAM_NO_EOT)) {
> -                       ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> -                                                    DMA_PREP_INTERRUPT);
> -                       if (ret)
> -                               return ret;
> -               }
> -       }
> -
> -       return 0;
> -}
> -
> -static int prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> -                            int reg_off, const void *vaddr, int size,
> -                            bool flow_control)
> -{
> -       struct desc_info *desc;
> -       struct dma_async_tx_descriptor *dma_desc;
> -       struct scatterlist *sgl;
> -       struct dma_slave_config slave_conf;
> -       struct qcom_adm_peripheral_config periph_conf = {};
> -       enum dma_transfer_direction dir_eng;
> -       int ret;
> -
> -       desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> -       if (!desc)
> -               return -ENOMEM;
> -
> -       sgl = &desc->adm_sgl;
> -
> -       sg_init_one(sgl, vaddr, size);
> -
> -       if (read) {
> -               dir_eng = DMA_DEV_TO_MEM;
> -               desc->dir = DMA_FROM_DEVICE;
> -       } else {
> -               dir_eng = DMA_MEM_TO_DEV;
> -               desc->dir = DMA_TO_DEVICE;
> -       }
> -
> -       ret = dma_map_sg(nandc->dev, sgl, 1, desc->dir);
> -       if (ret == 0) {
> -               ret = -ENOMEM;
> -               goto err;
> -       }
> -
> -       memset(&slave_conf, 0x00, sizeof(slave_conf));
> -
> -       slave_conf.device_fc = flow_control;
> -       if (read) {
> -               slave_conf.src_maxburst = 16;
> -               slave_conf.src_addr = nandc->base_dma + reg_off;
> -               if (nandc->data_crci) {
> -                       periph_conf.crci = nandc->data_crci;
> -                       slave_conf.peripheral_config = &periph_conf;
> -                       slave_conf.peripheral_size = sizeof(periph_conf);
> -               }
> -       } else {
> -               slave_conf.dst_maxburst = 16;
> -               slave_conf.dst_addr = nandc->base_dma + reg_off;
> -               if (nandc->cmd_crci) {
> -                       periph_conf.crci = nandc->cmd_crci;
> -                       slave_conf.peripheral_config = &periph_conf;
> -                       slave_conf.peripheral_size = sizeof(periph_conf);
> -               }
> -       }
> -
> -       ret = dmaengine_slave_config(nandc->chan, &slave_conf);
> -       if (ret) {
> -               dev_err(nandc->dev, "failed to configure dma channel\n");
> -               goto err;
> -       }
> -
> -       dma_desc = dmaengine_prep_slave_sg(nandc->chan, sgl, 1, dir_eng, 0);
> -       if (!dma_desc) {
> -               dev_err(nandc->dev, "failed to prepare desc\n");
> -               ret = -EINVAL;
> -               goto err;
> -       }
> -
> -       desc->dma_desc = dma_desc;
> -
> -       list_add_tail(&desc->node, &nandc->desc_list);
> -
> -       return 0;
> -err:
> -       kfree(desc);
> -
> -       return ret;
> -}
> -
> -/*
> - * read_reg_dma:       prepares a descriptor to read a given number of
> - *                     contiguous registers to the reg_read_buf pointer
> - *
> - * @first:             offset of the first register in the contiguous block
> - * @num_regs:          number of registers to read
> - * @flags:             flags to control DMA descriptor preparation
> - */
> -static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> -                       int num_regs, unsigned int flags)
> -{
> -       bool flow_control = false;
> -       void *vaddr;
> -
> -       vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> -       nandc->reg_read_pos += num_regs;
> -
> -       if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> -               first = dev_cmd_reg_addr(nandc, first);
> -
> -       if (nandc->props->is_bam)
> -               return prep_bam_dma_desc_cmd(nandc, true, first, vaddr,
> -                                            num_regs, flags);
> -
> -       if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> -               flow_control = true;
> -
> -       return prep_adm_dma_desc(nandc, true, first, vaddr,
> -                                num_regs * sizeof(u32), flow_control);
> -}
> -
> -/*
> - * write_reg_dma:      prepares a descriptor to write a given number of
> - *                     contiguous registers
> - *
> - * @first:             offset of the first register in the contiguous block
> - * @num_regs:          number of registers to write
> - * @flags:             flags to control DMA descriptor preparation
> - */
> -static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> -                        int num_regs, unsigned int flags)
> -{
> -       bool flow_control = false;
> -       struct nandc_regs *regs = nandc->regs;
> -       void *vaddr;
> -
> -       vaddr = offset_to_nandc_reg(regs, first);
> -
> -       if (first == NAND_ERASED_CW_DETECT_CFG) {
> -               if (flags & NAND_ERASED_CW_SET)
> -                       vaddr = &regs->erased_cw_detect_cfg_set;
> -               else
> -                       vaddr = &regs->erased_cw_detect_cfg_clr;
> -       }
> -
> -       if (first == NAND_EXEC_CMD)
> -               flags |= NAND_BAM_NWD;
> -
> -       if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> -               first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD1);
> -
> -       if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> -               first = dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD);
> -
> -       if (nandc->props->is_bam)
> -               return prep_bam_dma_desc_cmd(nandc, false, first, vaddr,
> -                                            num_regs, flags);
> -
> -       if (first == NAND_FLASH_CMD)
> -               flow_control = true;
> -
> -       return prep_adm_dma_desc(nandc, false, first, vaddr,
> -                                num_regs * sizeof(u32), flow_control);
> -}
> -
> -/*
> - * read_data_dma:      prepares a DMA descriptor to transfer data from the
> - *                     controller's internal buffer to the buffer 'vaddr'
> - *
> - * @reg_off:           offset within the controller's data buffer
> - * @vaddr:             virtual address of the buffer we want to write to
> - * @size:              DMA transaction size in bytes
> - * @flags:             flags to control DMA descriptor preparation
> - */
> -static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> -                        const u8 *vaddr, int size, unsigned int flags)
> -{
> -       if (nandc->props->is_bam)
> -               return prep_bam_dma_desc_data(nandc, true, vaddr, size, flags);
> -
> -       return prep_adm_dma_desc(nandc, true, reg_off, vaddr, size, false);
> -}
> -
> -/*
> - * write_data_dma:     prepares a DMA descriptor to transfer data from
> - *                     'vaddr' to the controller's internal buffer
> - *
> - * @reg_off:           offset within the controller's data buffer
> - * @vaddr:             virtual address of the buffer we want to read from
> - * @size:              DMA transaction size in bytes
> - * @flags:             flags to control DMA descriptor preparation
> - */
> -static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> -                         const u8 *vaddr, int size, unsigned int flags)
> -{
> -       if (nandc->props->is_bam)
> -               return prep_bam_dma_desc_data(nandc, false, vaddr, size, flags);
> -
> -       return prep_adm_dma_desc(nandc, false, reg_off, vaddr, size, false);
> -}
> -
> -/*
> - * Helper to prepare DMA descriptors for configuring registers
> - * before reading a NAND page.
> - */
> -static void config_nand_page_read(struct nand_chip *chip)
> -{
> -       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> -
> -       write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> -       write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
> -       if (!nandc->props->qpic_v2)
> -               write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
> -       write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
> -       write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
> -                     NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
> -}
> -
>  /*
>   * Helper to prepare DMA descriptors for configuring registers
>   * before reading each codeword in NAND page.
> @@ -1245,20 +267,37 @@ config_nand_cw_read(struct nand_chip *chip, bool use_ecc, int cw)
>                 reg = NAND_READ_LOCATION_LAST_CW_0;
>
>         if (nandc->props->is_bam)
> -               write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
> +               qcom_write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
>
> -       write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> -       write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>
>         if (use_ecc) {
> -               read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
> -               read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
> -                            NAND_BAM_NEXT_SGL);
> +               qcom_read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
> +               qcom_read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
> +                                 NAND_BAM_NEXT_SGL);
>         } else {
> -               read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +               qcom_read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
>         }
>  }
>
> +/*
> + * Helper to prepare DMA descriptors for configuring registers
> + * before reading a NAND page.
> + */
> +void config_nand_page_read(struct nand_chip *chip)
> +{
> +       struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +
> +       qcom_write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> +       qcom_write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
> +       if (!nandc->props->qpic_v2)
> +               qcom_write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1, 0);
> +       qcom_write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1, 0);
> +       qcom_write_reg_dma(nandc, NAND_ERASED_CW_DETECT_CFG, 1,
> +                          NAND_ERASED_CW_SET | NAND_BAM_NEXT_SGL);
> +}
> +
>  /*
>   * Helper to prepare dma descriptors to configure registers needed for reading a
>   * single codeword in page
> @@ -1279,11 +318,11 @@ static void config_nand_page_write(struct nand_chip *chip)
>  {
>         struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> -       write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> -       write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
> +       qcom_write_reg_dma(nandc, NAND_ADDR0, 2, 0);
> +       qcom_write_reg_dma(nandc, NAND_DEV0_CFG0, 3, 0);
>         if (!nandc->props->qpic_v2)
> -               write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1,
> -                             NAND_BAM_NEXT_SGL);
> +               qcom_write_reg_dma(nandc, NAND_EBI2_ECC_BUF_CFG, 1,
> +                                  NAND_BAM_NEXT_SGL);
>  }
>
>  /*
> @@ -1294,95 +333,13 @@ static void config_nand_cw_write(struct nand_chip *chip)
>  {
>         struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> -       write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> -       write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>
> -       read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +       qcom_read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
>
> -       write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
> -       write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
> -}
> -
> -/* helpers to submit/free our list of dma descriptors */
> -static int submit_descs(struct qcom_nand_controller *nandc)
> -{
> -       struct desc_info *desc, *n;
> -       dma_cookie_t cookie = 0;
> -       struct bam_transaction *bam_txn = nandc->bam_txn;
> -       int ret = 0;
> -
> -       if (nandc->props->is_bam) {
> -               if (bam_txn->rx_sgl_pos > bam_txn->rx_sgl_start) {
> -                       ret = prepare_bam_async_desc(nandc, nandc->rx_chan, 0);
> -                       if (ret)
> -                               goto err_unmap_free_desc;
> -               }
> -
> -               if (bam_txn->tx_sgl_pos > bam_txn->tx_sgl_start) {
> -                       ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> -                                                  DMA_PREP_INTERRUPT);
> -                       if (ret)
> -                               goto err_unmap_free_desc;
> -               }
> -
> -               if (bam_txn->cmd_sgl_pos > bam_txn->cmd_sgl_start) {
> -                       ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> -                                                  DMA_PREP_CMD);
> -                       if (ret)
> -                               goto err_unmap_free_desc;
> -               }
> -       }
> -
> -       list_for_each_entry(desc, &nandc->desc_list, node)
> -               cookie = dmaengine_submit(desc->dma_desc);
> -
> -       if (nandc->props->is_bam) {
> -               bam_txn->last_cmd_desc->callback = qpic_bam_dma_done;
> -               bam_txn->last_cmd_desc->callback_param = bam_txn;
> -               if (bam_txn->last_data_desc) {
> -                       bam_txn->last_data_desc->callback = qpic_bam_dma_done;
> -                       bam_txn->last_data_desc->callback_param = bam_txn;
> -                       bam_txn->wait_second_completion = true;
> -               }
> -
> -               dma_async_issue_pending(nandc->tx_chan);
> -               dma_async_issue_pending(nandc->rx_chan);
> -               dma_async_issue_pending(nandc->cmd_chan);
> -
> -               if (!wait_for_completion_timeout(&bam_txn->txn_done,
> -                                                QPIC_NAND_COMPLETION_TIMEOUT))
> -                       ret = -ETIMEDOUT;
> -       } else {
> -               if (dma_sync_wait(nandc->chan, cookie) != DMA_COMPLETE)
> -                       ret = -ETIMEDOUT;
> -       }
> -
> -err_unmap_free_desc:
> -       /*
> -        * Unmap the dma sg_list and free the desc allocated by both
> -        * prepare_bam_async_desc() and prep_adm_dma_desc() functions.
> -        */
> -       list_for_each_entry_safe(desc, n, &nandc->desc_list, node) {
> -               list_del(&desc->node);
> -
> -               if (nandc->props->is_bam)
> -                       dma_unmap_sg(nandc->dev, desc->bam_sgl,
> -                                    desc->sgl_cnt, desc->dir);
> -               else
> -                       dma_unmap_sg(nandc->dev, &desc->adm_sgl, 1,
> -                                    desc->dir);
> -
> -               kfree(desc);
> -       }
> -
> -       return ret;
> -}
> -
> -/* reset the register read buffer for next NAND operation */
> -static void clear_read_regs(struct qcom_nand_controller *nandc)
> -{
> -       nandc->reg_read_pos = 0;
> -       nandc_read_buffer_sync(nandc, false);
> +       qcom_write_reg_dma(nandc, NAND_FLASH_STATUS, 1, 0);
> +       qcom_write_reg_dma(nandc, NAND_READ_STATUS, 1, NAND_BAM_NEXT_SGL);
>  }
>
>  /*
> @@ -1446,7 +403,7 @@ static int check_flash_errors(struct qcom_nand_host *host, int cw_cnt)
>         struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>         int i;
>
> -       nandc_read_buffer_sync(nandc, true);
> +       qcom_nandc_read_buffer_sync(nandc, true);
>
>         for (i = 0; i < cw_cnt; i++) {
>                 u32 flash = le32_to_cpu(nandc->reg_read_buf[i]);
> @@ -1473,13 +430,13 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
>         nand_read_page_op(chip, page, 0, NULL, 0);
>         nandc->buf_count = 0;
>         nandc->buf_start = 0;
> -       clear_read_regs(nandc);
> +       qcom_clear_read_regs(nandc);
>         host->use_ecc = false;
>
>         if (nandc->props->qpic_v2)
>                 raw_cw = ecc->steps - 1;
>
> -       clear_bam_transaction(nandc);
> +       qcom_clear_bam_transaction(nandc);
>         set_address(host, host->cw_size * cw, page);
>         update_rw_regs(host, 1, true, raw_cw);
>         config_nand_page_read(chip);
> @@ -1512,18 +469,18 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
>
>         config_nand_cw_read(chip, false, raw_cw);
>
> -       read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
> +       qcom_read_data_dma(nandc, reg_off, data_buf, data_size1, 0);
>         reg_off += data_size1;
>
> -       read_data_dma(nandc, reg_off, oob_buf, oob_size1, 0);
> +       qcom_read_data_dma(nandc, reg_off, oob_buf, oob_size1, 0);
>         reg_off += oob_size1;
>
> -       read_data_dma(nandc, reg_off, data_buf + data_size1, data_size2, 0);
> +       qcom_read_data_dma(nandc, reg_off, data_buf + data_size1, data_size2, 0);
>         reg_off += data_size2;
>
> -       read_data_dma(nandc, reg_off, oob_buf + oob_size1, oob_size2, 0);
> +       qcom_read_data_dma(nandc, reg_off, oob_buf + oob_size1, oob_size2, 0);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to read raw cw %d\n", cw);
>                 return ret;
> @@ -1621,7 +578,7 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf,
>         u8 *data_buf_start = data_buf, *oob_buf_start = oob_buf;
>
>         buf = (struct read_stats *)nandc->reg_read_buf;
> -       nandc_read_buffer_sync(nandc, true);
> +       qcom_nandc_read_buffer_sync(nandc, true);
>
>         for (i = 0; i < ecc->steps; i++, buf++) {
>                 u32 flash, buffer, erased_cw;
> @@ -1750,8 +707,8 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
>                 config_nand_cw_read(chip, true, i);
>
>                 if (data_buf)
> -                       read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
> -                                     data_size, 0);
> +                       qcom_read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
> +                                          data_size, 0);
>
>                 /*
>                  * when ecc is enabled, the controller doesn't read the real
> @@ -1766,8 +723,8 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
>                         for (j = 0; j < host->bbm_size; j++)
>                                 *oob_buf++ = 0xff;
>
> -                       read_data_dma(nandc, FLASH_BUF_ACC + data_size,
> -                                     oob_buf, oob_size, 0);
> +                       qcom_read_data_dma(nandc, FLASH_BUF_ACC + data_size,
> +                                          oob_buf, oob_size, 0);
>                 }
>
>                 if (data_buf)
> @@ -1776,7 +733,7 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
>                         oob_buf += oob_size;
>         }
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to read page/oob\n");
>                 return ret;
> @@ -1797,7 +754,7 @@ static int copy_last_cw(struct qcom_nand_host *host, int page)
>         int size;
>         int ret;
>
> -       clear_read_regs(nandc);
> +       qcom_clear_read_regs(nandc);
>
>         size = host->use_ecc ? host->cw_data : host->cw_size;
>
> @@ -1809,9 +766,9 @@ static int copy_last_cw(struct qcom_nand_host *host, int page)
>
>         config_nand_single_cw_page_read(chip, host->use_ecc, ecc->steps - 1);
>
> -       read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);
> +       qcom_read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer, size, 0);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret)
>                 dev_err(nandc->dev, "failed to copy last codeword\n");
>
> @@ -1897,14 +854,14 @@ static int qcom_nandc_read_page(struct nand_chip *chip, u8 *buf,
>         nandc->buf_count = 0;
>         nandc->buf_start = 0;
>         host->use_ecc = true;
> -       clear_read_regs(nandc);
> +       qcom_clear_read_regs(nandc);
>         set_address(host, 0, page);
>         update_rw_regs(host, ecc->steps, true, 0);
>
>         data_buf = buf;
>         oob_buf = oob_required ? chip->oob_poi : NULL;
>
> -       clear_bam_transaction(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         return read_page_ecc(host, data_buf, oob_buf, page);
>  }
> @@ -1945,8 +902,8 @@ static int qcom_nandc_read_oob(struct nand_chip *chip, int page)
>         if (host->nr_boot_partitions)
>                 qcom_nandc_codeword_fixup(host, page);
>
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         host->use_ecc = true;
>         set_address(host, 0, page);
> @@ -1973,8 +930,8 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const u8 *buf,
>         set_address(host, 0, page);
>         nandc->buf_count = 0;
>         nandc->buf_start = 0;
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         data_buf = (u8 *)buf;
>         oob_buf = chip->oob_poi;
> @@ -1995,8 +952,8 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const u8 *buf,
>                         oob_size = ecc->bytes;
>                 }
>
> -               write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size,
> -                              i == (ecc->steps - 1) ? NAND_BAM_NO_EOT : 0);
> +               qcom_write_data_dma(nandc, FLASH_BUF_ACC, data_buf, data_size,
> +                                   i == (ecc->steps - 1) ? NAND_BAM_NO_EOT : 0);
>
>                 /*
>                  * when ECC is enabled, we don't really need to write anything
> @@ -2008,8 +965,8 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const u8 *buf,
>                 if (qcom_nandc_is_last_cw(ecc, i)) {
>                         oob_buf += host->bbm_size;
>
> -                       write_data_dma(nandc, FLASH_BUF_ACC + data_size,
> -                                      oob_buf, oob_size, 0);
> +                       qcom_write_data_dma(nandc, FLASH_BUF_ACC + data_size,
> +                                           oob_buf, oob_size, 0);
>                 }
>
>                 config_nand_cw_write(chip);
> @@ -2018,7 +975,7 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const u8 *buf,
>                 oob_buf += oob_size;
>         }
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to write page\n");
>                 return ret;
> @@ -2043,8 +1000,8 @@ static int qcom_nandc_write_page_raw(struct nand_chip *chip,
>                 qcom_nandc_codeword_fixup(host, page);
>
>         nand_prog_page_begin_op(chip, page, 0, NULL, 0);
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         data_buf = (u8 *)buf;
>         oob_buf = chip->oob_poi;
> @@ -2070,28 +1027,28 @@ static int qcom_nandc_write_page_raw(struct nand_chip *chip,
>                         oob_size2 = host->ecc_bytes_hw + host->spare_bytes;
>                 }
>
> -               write_data_dma(nandc, reg_off, data_buf, data_size1,
> -                              NAND_BAM_NO_EOT);
> +               qcom_write_data_dma(nandc, reg_off, data_buf, data_size1,
> +                                   NAND_BAM_NO_EOT);
>                 reg_off += data_size1;
>                 data_buf += data_size1;
>
> -               write_data_dma(nandc, reg_off, oob_buf, oob_size1,
> -                              NAND_BAM_NO_EOT);
> +               qcom_write_data_dma(nandc, reg_off, oob_buf, oob_size1,
> +                                   NAND_BAM_NO_EOT);
>                 reg_off += oob_size1;
>                 oob_buf += oob_size1;
>
> -               write_data_dma(nandc, reg_off, data_buf, data_size2,
> -                              NAND_BAM_NO_EOT);
> +               qcom_write_data_dma(nandc, reg_off, data_buf, data_size2,
> +                                   NAND_BAM_NO_EOT);
>                 reg_off += data_size2;
>                 data_buf += data_size2;
>
> -               write_data_dma(nandc, reg_off, oob_buf, oob_size2, 0);
> +               qcom_write_data_dma(nandc, reg_off, oob_buf, oob_size2, 0);
>                 oob_buf += oob_size2;
>
>                 config_nand_cw_write(chip);
>         }
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to write raw page\n");
>                 return ret;
> @@ -2121,7 +1078,7 @@ static int qcom_nandc_write_oob(struct nand_chip *chip, int page)
>                 qcom_nandc_codeword_fixup(host, page);
>
>         host->use_ecc = true;
> -       clear_bam_transaction(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         /* calculate the data and oob size for the last codeword/step */
>         data_size = ecc->size - ((ecc->steps - 1) << 2);
> @@ -2136,11 +1093,11 @@ static int qcom_nandc_write_oob(struct nand_chip *chip, int page)
>         update_rw_regs(host, 1, false, 0);
>
>         config_nand_page_write(chip);
> -       write_data_dma(nandc, FLASH_BUF_ACC,
> -                      nandc->data_buffer, data_size + oob_size, 0);
> +       qcom_write_data_dma(nandc, FLASH_BUF_ACC,
> +                           nandc->data_buffer, data_size + oob_size, 0);
>         config_nand_cw_write(chip);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to write oob\n");
>                 return ret;
> @@ -2167,7 +1124,7 @@ static int qcom_nandc_block_bad(struct nand_chip *chip, loff_t ofs)
>          */
>         host->use_ecc = false;
>
> -       clear_bam_transaction(nandc);
> +       qcom_clear_bam_transaction(nandc);
>         ret = copy_last_cw(host, page);
>         if (ret)
>                 goto err;
> @@ -2194,8 +1151,8 @@ static int qcom_nandc_block_markbad(struct nand_chip *chip, loff_t ofs)
>         struct nand_ecc_ctrl *ecc = &chip->ecc;
>         int page, ret;
>
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         /*
>          * to mark the BBM as bad, we flash the entire last codeword with 0s.
> @@ -2212,11 +1169,11 @@ static int qcom_nandc_block_markbad(struct nand_chip *chip, loff_t ofs)
>         update_rw_regs(host, 1, false, ecc->steps - 1);
>
>         config_nand_page_write(chip);
> -       write_data_dma(nandc, FLASH_BUF_ACC,
> -                      nandc->data_buffer, host->cw_size, 0);
> +       qcom_write_data_dma(nandc, FLASH_BUF_ACC,
> +                           nandc->data_buffer, host->cw_size, 0);
>         config_nand_cw_write(chip);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure to update BBM\n");
>                 return ret;
> @@ -2456,14 +1413,14 @@ static int qcom_nand_attach_chip(struct nand_chip *chip)
>         mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
>         /* Free the initially allocated BAM transaction for reading the ONFI params */
>         if (nandc->props->is_bam)
> -               free_bam_transaction(nandc);
> +               qcom_free_bam_transaction(nandc);
>
>         nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
>                                      cwperpage);
>
>         /* Now allocate the BAM transaction based on updated max_cwperpage */
>         if (nandc->props->is_bam) {
> -               nandc->bam_txn = alloc_bam_transaction(nandc);
> +               nandc->bam_txn = qcom_alloc_bam_transaction(nandc);
>                 if (!nandc->bam_txn) {
>                         dev_err(nandc->dev,
>                                 "failed to allocate bam transaction\n");
> @@ -2663,7 +1620,7 @@ static int qcom_wait_rdy_poll(struct nand_chip *chip, unsigned int time_ms)
>         unsigned long start = jiffies + msecs_to_jiffies(time_ms);
>         u32 flash;
>
> -       nandc_read_buffer_sync(nandc, true);
> +       qcom_nandc_read_buffer_sync(nandc, true);
>
>         do {
>                 flash = le32_to_cpu(nandc->reg_read_buf[0]);
> @@ -2703,23 +1660,23 @@ static int qcom_read_status_exec(struct nand_chip *chip,
>         nandc->buf_start = 0;
>         host->use_ecc = false;
>
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
>         nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>
> -       write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> -       write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> -       read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure in submitting status descriptor\n");
>                 goto err_out;
>         }
>
> -       nandc_read_buffer_sync(nandc, true);
> +       qcom_nandc_read_buffer_sync(nandc, true);
>
>         for (i = 0; i < num_cw; i++) {
>                 flash_status = le32_to_cpu(nandc->reg_read_buf[i]);
> @@ -2760,8 +1717,8 @@ static int qcom_read_id_type_exec(struct nand_chip *chip, const struct nand_subo
>         nandc->buf_start = 0;
>         host->use_ecc = false;
>
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
>         nandc_set_reg(chip, NAND_ADDR0, q_op.addr1_reg);
> @@ -2771,12 +1728,12 @@ static int qcom_read_id_type_exec(struct nand_chip *chip, const struct nand_subo
>
>         nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>
> -       write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
> -       write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>
> -       read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
> +       qcom_read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure in submitting read id descriptor\n");
>                 goto err_out;
> @@ -2786,7 +1743,7 @@ static int qcom_read_id_type_exec(struct nand_chip *chip, const struct nand_subo
>         op_id = q_op.data_instr_idx;
>         len = nand_subop_get_data_len(subop, op_id);
>
> -       nandc_read_buffer_sync(nandc, true);
> +       qcom_nandc_read_buffer_sync(nandc, true);
>         memcpy(instr->ctx.data.buf.in, nandc->reg_read_buf, len);
>
>  err_out:
> @@ -2823,21 +1780,21 @@ static int qcom_misc_cmd_type_exec(struct nand_chip *chip, const struct nand_sub
>         nandc->buf_start = 0;
>         host->use_ecc = false;
>
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
>         nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>
> -       write_reg_dma(nandc, NAND_FLASH_CMD, instrs, NAND_BAM_NEXT_SGL);
> -       (q_op.cmd_reg == OP_BLOCK_ERASE) ? write_reg_dma(nandc, NAND_DEV0_CFG0,
> -       2, NAND_BAM_NEXT_SGL) : read_reg_dma(nandc,
> +       qcom_write_reg_dma(nandc, NAND_FLASH_CMD, instrs, NAND_BAM_NEXT_SGL);
> +       (q_op.cmd_reg == OP_BLOCK_ERASE) ? qcom_write_reg_dma(nandc, NAND_DEV0_CFG0,
> +       2, NAND_BAM_NEXT_SGL) : qcom_read_reg_dma(nandc,
>         NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
>
> -       write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> -       read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +       qcom_write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +       qcom_read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure in submitting misc descriptor\n");
>                 goto err_out;
> @@ -2870,8 +1827,8 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
>         nandc->buf_count = 0;
>         nandc->buf_start = 0;
>         host->use_ecc = false;
> -       clear_read_regs(nandc);
> -       clear_bam_transaction(nandc);
> +       qcom_clear_read_regs(nandc);
> +       qcom_clear_bam_transaction(nandc);
>
>         nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
>
> @@ -2914,8 +1871,8 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
>         nandc_set_read_loc(chip, 0, 0, 0, len, 1);
>
>         if (!nandc->props->qpic_v2) {
> -               write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
> -               write_reg_dma(nandc, NAND_DEV_CMD1, 1, NAND_BAM_NEXT_SGL);
> +               qcom_write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
> +               qcom_write_reg_dma(nandc, NAND_DEV_CMD1, 1, NAND_BAM_NEXT_SGL);
>         }
>
>         nandc->buf_count = len;
> @@ -2923,16 +1880,16 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
>
>         config_nand_single_cw_page_read(chip, false, 0);
>
> -       read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
> -                     nandc->buf_count, 0);
> +       qcom_read_data_dma(nandc, FLASH_BUF_ACC, nandc->data_buffer,
> +                          nandc->buf_count, 0);
>
>         /* restore CMD1 and VLD regs */
>         if (!nandc->props->qpic_v2) {
> -               write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1, 0);
> -               write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1, NAND_BAM_NEXT_SGL);
> +               qcom_write_reg_dma(nandc, NAND_DEV_CMD1_RESTORE, 1, 0);
> +               qcom_write_reg_dma(nandc, NAND_DEV_CMD_VLD_RESTORE, 1, NAND_BAM_NEXT_SGL);
>         }
>
> -       ret = submit_descs(nandc);
> +       ret = qcom_submit_descs(nandc);
>         if (ret) {
>                 dev_err(nandc->dev, "failure in submitting param page descriptor\n");
>                 goto err_out;
> @@ -3016,136 +1973,6 @@ static const struct nand_controller_ops qcom_nandc_ops = {
>         .exec_op = qcom_nand_exec_op,
>  };
>
> -static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> -{
> -       if (nandc->props->is_bam) {
> -               if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma))
> -                       dma_unmap_single(nandc->dev, nandc->reg_read_dma,
> -                                        MAX_REG_RD *
> -                                        sizeof(*nandc->reg_read_buf),
> -                                        DMA_FROM_DEVICE);
> -
> -               if (nandc->tx_chan)
> -                       dma_release_channel(nandc->tx_chan);
> -
> -               if (nandc->rx_chan)
> -                       dma_release_channel(nandc->rx_chan);
> -
> -               if (nandc->cmd_chan)
> -                       dma_release_channel(nandc->cmd_chan);
> -       } else {
> -               if (nandc->chan)
> -                       dma_release_channel(nandc->chan);
> -       }
> -}
> -
> -static int qcom_nandc_alloc(struct qcom_nand_controller *nandc)
> -{
> -       int ret;
> -
> -       ret = dma_set_coherent_mask(nandc->dev, DMA_BIT_MASK(32));
> -       if (ret) {
> -               dev_err(nandc->dev, "failed to set DMA mask\n");
> -               return ret;
> -       }
> -
> -       /*
> -        * we use the internal buffer for reading ONFI params, reading small
> -        * data like ID and status, and preforming read-copy-write operations
> -        * when writing to a codeword partially. 532 is the maximum possible
> -        * size of a codeword for our nand controller
> -        */
> -       nandc->buf_size = 532;
> -
> -       nandc->data_buffer = devm_kzalloc(nandc->dev, nandc->buf_size, GFP_KERNEL);
> -       if (!nandc->data_buffer)
> -               return -ENOMEM;
> -
> -       nandc->regs = devm_kzalloc(nandc->dev, sizeof(*nandc->regs), GFP_KERNEL);
> -       if (!nandc->regs)
> -               return -ENOMEM;
> -
> -       nandc->reg_read_buf = devm_kcalloc(nandc->dev, MAX_REG_RD,
> -                                          sizeof(*nandc->reg_read_buf),
> -                                          GFP_KERNEL);
> -       if (!nandc->reg_read_buf)
> -               return -ENOMEM;
> -
> -       if (nandc->props->is_bam) {
> -               nandc->reg_read_dma =
> -                       dma_map_single(nandc->dev, nandc->reg_read_buf,
> -                                      MAX_REG_RD *
> -                                      sizeof(*nandc->reg_read_buf),
> -                                      DMA_FROM_DEVICE);
> -               if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) {
> -                       dev_err(nandc->dev, "failed to DMA MAP reg buffer\n");
> -                       return -EIO;
> -               }
> -
> -               nandc->tx_chan = dma_request_chan(nandc->dev, "tx");
> -               if (IS_ERR(nandc->tx_chan)) {
> -                       ret = PTR_ERR(nandc->tx_chan);
> -                       nandc->tx_chan = NULL;
> -                       dev_err_probe(nandc->dev, ret,
> -                                     "tx DMA channel request failed\n");
> -                       goto unalloc;
> -               }
> -
> -               nandc->rx_chan = dma_request_chan(nandc->dev, "rx");
> -               if (IS_ERR(nandc->rx_chan)) {
> -                       ret = PTR_ERR(nandc->rx_chan);
> -                       nandc->rx_chan = NULL;
> -                       dev_err_probe(nandc->dev, ret,
> -                                     "rx DMA channel request failed\n");
> -                       goto unalloc;
> -               }
> -
> -               nandc->cmd_chan = dma_request_chan(nandc->dev, "cmd");
> -               if (IS_ERR(nandc->cmd_chan)) {
> -                       ret = PTR_ERR(nandc->cmd_chan);
> -                       nandc->cmd_chan = NULL;
> -                       dev_err_probe(nandc->dev, ret,
> -                                     "cmd DMA channel request failed\n");
> -                       goto unalloc;
> -               }
> -
> -               /*
> -                * Initially allocate BAM transaction to read ONFI param page.
> -                * After detecting all the devices, this BAM transaction will
> -                * be freed and the next BAM transaction will be allocated with
> -                * maximum codeword size
> -                */
> -               nandc->max_cwperpage = 1;
> -               nandc->bam_txn = alloc_bam_transaction(nandc);
> -               if (!nandc->bam_txn) {
> -                       dev_err(nandc->dev,
> -                               "failed to allocate bam transaction\n");
> -                       ret = -ENOMEM;
> -                       goto unalloc;
> -               }
> -       } else {
> -               nandc->chan = dma_request_chan(nandc->dev, "rxtx");
> -               if (IS_ERR(nandc->chan)) {
> -                       ret = PTR_ERR(nandc->chan);
> -                       nandc->chan = NULL;
> -                       dev_err_probe(nandc->dev, ret,
> -                                     "rxtx DMA channel request failed\n");
> -                       return ret;
> -               }
> -       }
> -
> -       INIT_LIST_HEAD(&nandc->desc_list);
> -       INIT_LIST_HEAD(&nandc->host_list);
> -
> -       nand_controller_init(&nandc->controller);
> -       nandc->controller.ops = &qcom_nandc_ops;
> -
> -       return 0;
> -unalloc:
> -       qcom_nandc_unalloc(nandc);
> -       return ret;
> -}
> -
>  /* one time setup of a few nand controller registers */
>  static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
>  {
> @@ -3427,6 +2254,9 @@ static int qcom_nandc_probe(struct platform_device *pdev)
>         if (ret)
>                 goto err_nandc_alloc;
>
> +       nand_controller_init(&nandc->controller);
> +       nandc->controller.ops = &qcom_nandc_ops;
> +
>         ret = qcom_nandc_setup(nandc);
>         if (ret)
>                 goto err_setup;
> @@ -3473,28 +2303,28 @@ static void qcom_nandc_remove(struct platform_device *pdev)
>                            DMA_BIDIRECTIONAL, 0);
>  }
>
> -static const struct qcom_nandc_props ipq806x_nandc_props = {
> +static struct qcom_nandc_props ipq806x_nandc_props = {
>         .ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
>         .is_bam = false,
>         .use_codeword_fixup = true,
>         .dev_cmd_reg_start = 0x0,
>  };
>
> -static const struct qcom_nandc_props ipq4019_nandc_props = {
> +static struct qcom_nandc_props ipq4019_nandc_props = {
>         .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>         .is_bam = true,
>         .is_qpic = true,
>         .dev_cmd_reg_start = 0x0,
>  };
>
> -static const struct qcom_nandc_props ipq8074_nandc_props = {
> +static struct qcom_nandc_props ipq8074_nandc_props = {
>         .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>         .is_bam = true,
>         .is_qpic = true,
>         .dev_cmd_reg_start = 0x7000,
>  };
>
> -static const struct qcom_nandc_props sdx55_nandc_props = {
> +static struct qcom_nandc_props sdx55_nandc_props = {
>         .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT),
>         .is_bam = true,
>         .is_qpic = true,
> diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
> new file mode 100644
> index 000000000000..aced15866627
> --- /dev/null
> +++ b/include/linux/mtd/nand-qpic-common.h
> @@ -0,0 +1,486 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * QCOM QPIC common APIs header file
> + *
> + * Copyright (c) 2023 Qualcomm Inc.
> + * Authors:     Md sadre Alam           <quic_mdalam@...cinc.com>
> + *             Sricharan R             <quic_srichara@...cinc.com>
> + *             Varadarajan Narayanan   <quic_varada@...cinc.com>

Oh, really?

> + *
> + */
> +#ifndef __MTD_NAND_QPIC_COMMON_H__
> +#define __MTD_NAND_QPIC_COMMON_H__
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dma/qcom_adm.h>
> +#include <linux/dma/qcom_bam_dma.h>
> +#include <linux/module.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +
> +/* NANDc reg offsets */
> +#define        NAND_FLASH_CMD                  0x00
> +#define        NAND_ADDR0                      0x04
> +#define        NAND_ADDR1                      0x08
> +#define        NAND_FLASH_CHIP_SELECT          0x0c
> +#define        NAND_EXEC_CMD                   0x10
> +#define        NAND_FLASH_STATUS               0x14
> +#define        NAND_BUFFER_STATUS              0x18
> +#define        NAND_DEV0_CFG0                  0x20
> +#define        NAND_DEV0_CFG1                  0x24
> +#define        NAND_DEV0_ECC_CFG               0x28
> +#define        NAND_AUTO_STATUS_EN             0x2c
> +#define        NAND_DEV1_CFG0                  0x30
> +#define        NAND_DEV1_CFG1                  0x34
> +#define        NAND_READ_ID                    0x40
> +#define        NAND_READ_STATUS                0x44
> +#define        NAND_DEV_CMD0                   0xa0
> +#define        NAND_DEV_CMD1                   0xa4
> +#define        NAND_DEV_CMD2                   0xa8
> +#define        NAND_DEV_CMD_VLD                0xac
> +#define        SFLASHC_BURST_CFG               0xe0
> +#define        NAND_ERASED_CW_DETECT_CFG       0xe8
> +#define        NAND_ERASED_CW_DETECT_STATUS    0xec
> +#define        NAND_EBI2_ECC_BUF_CFG           0xf0
> +#define        FLASH_BUF_ACC                   0x100
> +
> +#define        NAND_CTRL                       0xf00
> +#define        NAND_VERSION                    0xf08
> +#define        NAND_READ_LOCATION_0            0xf20
> +#define        NAND_READ_LOCATION_1            0xf24
> +#define        NAND_READ_LOCATION_2            0xf28
> +#define        NAND_READ_LOCATION_3            0xf2c
> +#define        NAND_READ_LOCATION_LAST_CW_0    0xf40
> +#define        NAND_READ_LOCATION_LAST_CW_1    0xf44
> +#define        NAND_READ_LOCATION_LAST_CW_2    0xf48
> +#define        NAND_READ_LOCATION_LAST_CW_3    0xf4c
> +
> +/* dummy register offsets, used by write_reg_dma */
> +#define        NAND_DEV_CMD1_RESTORE           0xdead
> +#define        NAND_DEV_CMD_VLD_RESTORE        0xbeef
> +
> +/* NAND_FLASH_CMD bits */
> +#define        PAGE_ACC                        BIT(4)
> +#define        LAST_PAGE                       BIT(5)
> +
> +/* NAND_FLASH_CHIP_SELECT bits */
> +#define        NAND_DEV_SEL                    0
> +#define        DM_EN                           BIT(2)
> +
> +/* NAND_FLASH_STATUS bits */
> +#define        FS_OP_ERR                       BIT(4)
> +#define        FS_READY_BSY_N                  BIT(5)
> +#define        FS_MPU_ERR                      BIT(8)
> +#define        FS_DEVICE_STS_ERR               BIT(16)
> +#define        FS_DEVICE_WP                    BIT(23)
> +
> +/* NAND_BUFFER_STATUS bits */
> +#define        BS_UNCORRECTABLE_BIT            BIT(8)
> +#define        BS_CORRECTABLE_ERR_MSK          0x1f
> +
> +/* NAND_DEVn_CFG0 bits */
> +#define        DISABLE_STATUS_AFTER_WRITE      4
> +#define        CW_PER_PAGE                     6
> +#define        UD_SIZE_BYTES                   9
> +#define        UD_SIZE_BYTES_MASK              GENMASK(18, 9)
> +#define        ECC_PARITY_SIZE_BYTES_RS        19
> +#define        SPARE_SIZE_BYTES                23
> +#define        SPARE_SIZE_BYTES_MASK           GENMASK(26, 23)
> +#define        NUM_ADDR_CYCLES                 27
> +#define        STATUS_BFR_READ                 30
> +#define        SET_RD_MODE_AFTER_STATUS        31
> +
> +/* NAND_DEVn_CFG0 bits */
> +#define        DEV0_CFG1_ECC_DISABLE           0
> +#define        WIDE_FLASH                      1
> +#define        NAND_RECOVERY_CYCLES            2
> +#define        CS_ACTIVE_BSY                   5
> +#define        BAD_BLOCK_BYTE_NUM              6
> +#define        BAD_BLOCK_IN_SPARE_AREA         16
> +#define        WR_RD_BSY_GAP                   17
> +#define        ENABLE_BCH_ECC                  27
> +
> +/* NAND_DEV0_ECC_CFG bits */
> +#define        ECC_CFG_ECC_DISABLE             0
> +#define        ECC_SW_RESET                    1
> +#define        ECC_MODE                        4
> +#define        ECC_PARITY_SIZE_BYTES_BCH       8
> +#define        ECC_NUM_DATA_BYTES              16
> +#define        ECC_NUM_DATA_BYTES_MASK         GENMASK(25, 16)
> +#define        ECC_FORCE_CLK_OPEN              30
> +
> +/* NAND_DEV_CMD1 bits */
> +#define        READ_ADDR                       0
> +
> +/* NAND_DEV_CMD_VLD bits */
> +#define        READ_START_VLD                  BIT(0)
> +#define        READ_STOP_VLD                   BIT(1)
> +#define        WRITE_START_VLD                 BIT(2)
> +#define        ERASE_START_VLD                 BIT(3)
> +#define        SEQ_READ_START_VLD              BIT(4)
> +
> +/* NAND_EBI2_ECC_BUF_CFG bits */
> +#define        NUM_STEPS                       0
> +
> +/* NAND_ERASED_CW_DETECT_CFG bits */
> +#define        ERASED_CW_ECC_MASK              1
> +#define        AUTO_DETECT_RES                 0
> +#define        MASK_ECC                        BIT(ERASED_CW_ECC_MASK)
> +#define        RESET_ERASED_DET                BIT(AUTO_DETECT_RES)
> +#define        ACTIVE_ERASED_DET               (0 << AUTO_DETECT_RES)
> +#define        CLR_ERASED_PAGE_DET             (RESET_ERASED_DET | MASK_ECC)
> +#define        SET_ERASED_PAGE_DET             (ACTIVE_ERASED_DET | MASK_ECC)
> +
> +/* NAND_ERASED_CW_DETECT_STATUS bits */
> +#define        PAGE_ALL_ERASED                 BIT(7)
> +#define        CODEWORD_ALL_ERASED             BIT(6)
> +#define        PAGE_ERASED                     BIT(5)
> +#define        CODEWORD_ERASED                 BIT(4)
> +#define        ERASED_PAGE                     (PAGE_ALL_ERASED | PAGE_ERASED)
> +#define        ERASED_CW                       (CODEWORD_ALL_ERASED | CODEWORD_ERASED)
> +
> +/* NAND_READ_LOCATION_n bits */
> +#define READ_LOCATION_OFFSET           0
> +#define READ_LOCATION_SIZE             16
> +#define READ_LOCATION_LAST             31
> +
> +/* Version Mask */
> +#define        NAND_VERSION_MAJOR_MASK         0xf0000000
> +#define        NAND_VERSION_MAJOR_SHIFT        28
> +#define        NAND_VERSION_MINOR_MASK         0x0fff0000
> +#define        NAND_VERSION_MINOR_SHIFT        16
> +
> +/* NAND OP_CMDs */
> +#define        OP_PAGE_READ                    0x2
> +#define        OP_PAGE_READ_WITH_ECC           0x3
> +#define        OP_PAGE_READ_WITH_ECC_SPARE     0x4
> +#define        OP_PAGE_READ_ONFI_READ          0x5
> +#define        OP_PROGRAM_PAGE                 0x6
> +#define        OP_PAGE_PROGRAM_WITH_ECC        0x7
> +#define        OP_PROGRAM_PAGE_SPARE           0x9
> +#define        OP_BLOCK_ERASE                  0xa
> +#define        OP_CHECK_STATUS                 0xc
> +#define        OP_FETCH_ID                     0xb
> +#define        OP_RESET_DEVICE                 0xd
> +
> +/* Default Value for NAND_DEV_CMD_VLD */
> +#define NAND_DEV_CMD_VLD_VAL           (READ_START_VLD | WRITE_START_VLD | \
> +                                        ERASE_START_VLD | SEQ_READ_START_VLD)
> +
> +/* NAND_CTRL bits */
> +#define        BAM_MODE_EN                     BIT(0)
> +
> +/*
> + * the NAND controller performs reads/writes with ECC in 516 byte chunks.
> + * the driver calls the chunks 'step' or 'codeword' interchangeably
> + */
> +#define        NANDC_STEP_SIZE                 512
> +
> +/*
> + * the largest page size we support is 8K, this will have 16 steps/codewords
> + * of 512 bytes each
> + */
> +#define        MAX_NUM_STEPS                   (SZ_8K / NANDC_STEP_SIZE)
> +
> +/* we read at most 3 registers per codeword scan */
> +#define        MAX_REG_RD                      (3 * MAX_NUM_STEPS)
> +
> +#define QPIC_PER_CW_CMD_ELEMENTS       32
> +#define QPIC_PER_CW_CMD_SGL            32
> +#define QPIC_PER_CW_DATA_SGL           8
> +
> +#define QPIC_NAND_COMPLETION_TIMEOUT   msecs_to_jiffies(2000)
> +
> +/*
> + * Flags used in DMA descriptor preparation helper functions
> + * (i.e. read_reg_dma/write_reg_dma/read_data_dma/write_data_dma)
> + */
> +/* Don't set the EOT in current tx BAM sgl */
> +#define NAND_BAM_NO_EOT                        BIT(0)
> +/* Set the NWD flag in current BAM sgl */
> +#define NAND_BAM_NWD                   BIT(1)
> +/* Finish writing in the current BAM sgl and start writing in another BAM sgl */
> +#define NAND_BAM_NEXT_SGL              BIT(2)
> +
> +/*
> + * Returns the actual register address for all NAND_DEV_ registers
> + * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> + */
> +#define dev_cmd_reg_addr(nandc, reg) ((nandc)->props->dev_cmd_reg_start + (reg))

Sensible prefixes are appreciated in the global headers too.

> +
> +/* Returns the NAND register physical address */
> +#define nandc_reg_phys(chip, offset) ((chip)->base_phys + (offset))
> +
> +/* Returns the dma address for reg read buffer */
> +#define reg_buf_dma_addr(chip, vaddr) \
> +       ((chip)->reg_read_dma + \
> +       ((u8 *)(vaddr) - (u8 *)(chip)->reg_read_buf))
> +
> +/*
> + * Erased codeword status is being used two times in single transfer so this
> + * flag will determine the current value of erased codeword status register
> + */
> +#define NAND_ERASED_CW_SET             BIT(4)
> +
> +#define MAX_ADDRESS_CYCLE              5
> +
> +/*
> + * This data type corresponds to the BAM transaction which will be used for all
> + * NAND transfers.
> + * @bam_ce - the array of BAM command elements
> + * @cmd_sgl - sgl for NAND BAM command pipe
> + * @data_sgl - sgl for NAND BAM consumer/producer pipe
> + * @last_data_desc - last DMA desc in data channel (tx/rx).
> + * @last_cmd_desc - last DMA desc in command channel.
> + * @txn_done - completion for NAND transfer.
> + * @bam_ce_pos - the index in bam_ce which is available for next sgl
> + * @bam_ce_start - the index in bam_ce which marks the start position ce
> + *                for current sgl. It will be used for size calculation
> + *                for current sgl
> + * @cmd_sgl_pos - current index in command sgl.
> + * @cmd_sgl_start - start index in command sgl.
> + * @tx_sgl_pos - current index in data sgl for tx.
> + * @tx_sgl_start - start index in data sgl for tx.
> + * @rx_sgl_pos - current index in data sgl for rx.
> + * @rx_sgl_start - start index in data sgl for rx.
> + * @wait_second_completion - wait for second DMA desc completion before making
> + *                          the NAND transfer completion.
> + */
> +struct bam_transaction {
> +       struct bam_cmd_element *bam_ce;
> +       struct scatterlist *cmd_sgl;
> +       struct scatterlist *data_sgl;
> +       struct dma_async_tx_descriptor *last_data_desc;
> +       struct dma_async_tx_descriptor *last_cmd_desc;
> +       struct completion txn_done;
> +       u32 bam_ce_pos;
> +       u32 bam_ce_start;
> +       u32 cmd_sgl_pos;
> +       u32 cmd_sgl_start;
> +       u32 tx_sgl_pos;
> +       u32 tx_sgl_start;
> +       u32 rx_sgl_pos;
> +       u32 rx_sgl_start;
> +       bool wait_second_completion;
> +};
> +
> +/*
> + * This data type corresponds to the nand dma descriptor
> + * @dma_desc - low level DMA engine descriptor
> + * @list - list for desc_info
> + *
> + * @adm_sgl - sgl which will be used for single sgl dma descriptor. Only used by
> + *           ADM
> + * @bam_sgl - sgl which will be used for dma descriptor. Only used by BAM
> + * @sgl_cnt - number of SGL in bam_sgl. Only used by BAM
> + * @dir - DMA transfer direction
> + */
> +struct desc_info {
> +       struct dma_async_tx_descriptor *dma_desc;
> +       struct list_head node;
> +
> +       union {
> +               struct scatterlist adm_sgl;
> +               struct {
> +                       struct scatterlist *bam_sgl;
> +                       int sgl_cnt;
> +               };
> +       };
> +       enum dma_data_direction dir;
> +};
> +
> +/*
> + * holds the current register values that we want to write. acts as a contiguous
> + * chunk of memory which we use to write the controller registers through DMA.
> + */
> +struct nandc_regs {
> +       __le32 cmd;
> +       __le32 addr0;
> +       __le32 addr1;
> +       __le32 chip_sel;
> +       __le32 exec;
> +
> +       __le32 cfg0;
> +       __le32 cfg1;
> +       __le32 ecc_bch_cfg;
> +
> +       __le32 clrflashstatus;
> +       __le32 clrreadstatus;
> +
> +       __le32 cmd1;
> +       __le32 vld;
> +
> +       __le32 orig_cmd1;
> +       __le32 orig_vld;
> +
> +       __le32 ecc_buf_cfg;
> +       __le32 read_location0;
> +       __le32 read_location1;
> +       __le32 read_location2;
> +       __le32 read_location3;
> +       __le32 read_location_last0;
> +       __le32 read_location_last1;
> +       __le32 read_location_last2;
> +       __le32 read_location_last3;
> +
> +       __le32 erased_cw_detect_cfg_clr;
> +       __le32 erased_cw_detect_cfg_set;
> +};

Is there any reason to export both register offsets and a containing struct?

> +
> +/*
> + * NAND controller data struct
> + *
> + * @dev:                       parent device
> + *
> + * @base:                      MMIO base
> + *
> + * @core_clk:                  controller clock
> + * @aon_clk:                   another controller clock
> + *
> + * @regs:                      a contiguous chunk of memory for DMA register
> + *                             writes. contains the register values to be
> + *                             written to controller
> + *
> + * @props:                     properties of current NAND controller,
> + *                             initialized via DT match data
> + *
> + * @controller:                        base controller structure
> + * @host_list:                 list containing all the chips attached to the
> + *                             controller
> + *
> + * @chan:                      dma channel
> + * @cmd_crci:                  ADM DMA CRCI for command flow control
> + * @data_crci:                 ADM DMA CRCI for data flow control
> + *
> + * @desc_list:                 DMA descriptor list (list of desc_infos)
> + *
> + * @data_buffer:               our local DMA buffer for page read/writes,
> + *                             used when we can't use the buffer provided
> + *                             by upper layers directly
> + * @reg_read_buf:              local buffer for reading back registers via DMA
> + *
> + * @base_phys:                 physical base address of controller registers
> + * @base_dma:                  dma base address of controller registers
> + * @reg_read_dma:              contains dma address for register read buffer
> + *
> + * @buf_size/count/start:      markers for chip->legacy.read_buf/write_buf
> + *                             functions
> + * @max_cwperpage:             maximum QPIC codewords required. calculated
> + *                             from all connected NAND devices pagesize
> + *
> + * @reg_read_pos:              marker for data read in reg_read_buf
> + *
> + * @cmd1/vld:                  some fixed controller register values
> + *
> + * @exec_opwrite:              flag to select correct number of code word
> + *                             while reading status
> + */
> +struct qcom_nand_controller {

If you need to export data structures, this usually means that
something is not that great with the design. Also, do you really need
qcom_nand_controller::controller in the SPI NOR case?

> +       struct device *dev;
> +
> +       void __iomem *base;
> +
> +       struct clk *core_clk;
> +       struct clk *aon_clk;
> +
> +       struct nandc_regs *regs;
> +       struct bam_transaction *bam_txn;
> +
> +       const struct qcom_nandc_props *props;
> +
> +       struct nand_controller controller;
> +       struct list_head host_list;
> +
> +       union {
> +               /* will be used only by QPIC for BAM DMA */
> +               struct {
> +                       struct dma_chan *tx_chan;
> +                       struct dma_chan *rx_chan;
> +                       struct dma_chan *cmd_chan;
> +               };
> +
> +               /* will be used only by EBI2 for ADM DMA */
> +               struct {
> +                       struct dma_chan *chan;
> +                       unsigned int cmd_crci;
> +                       unsigned int data_crci;
> +               };
> +       };
> +
> +       struct list_head desc_list;
> +
> +       u8              *data_buffer;
> +       __le32          *reg_read_buf;
> +
> +       phys_addr_t base_phys;
> +       dma_addr_t base_dma;
> +       dma_addr_t reg_read_dma;
> +
> +       int             buf_size;
> +       int             buf_count;
> +       int             buf_start;
> +       unsigned int    max_cwperpage;
> +
> +       int reg_read_pos;
> +
> +       u32 cmd1, vld;
> +       bool exec_opwrite;
> +};
> +
> +/*
> + * This data type corresponds to the NAND controller properties which varies
> + * among different NAND controllers.
> + * @ecc_modes - ecc mode for NAND
> + * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset
> + * @is_bam - whether NAND controller is using BAM
> + * @is_qpic - whether NAND CTRL is part of qpic IP
> + * @qpic_v2 - flag to indicate QPIC IP version 2
> + * @use_codeword_fixup - whether NAND has different layout for boot partitions
> + */
> +struct qcom_nandc_props {
> +       u32 ecc_modes;
> +       u32 dev_cmd_reg_start;
> +       bool is_bam;
> +       bool is_qpic;
> +       bool qpic_v2;
> +       bool use_codeword_fixup;
> +};
> +
> +void config_nand_page_read(struct nand_chip *chip);
> +void qcom_qpic_bam_dma_done(void *data);

So, what is the actual prefix? qcom_? Isn't that too broad? Not to
mention that config_nand_page_read isn't following even that style.

> +void qcom_nandc_read_buffer_sync(struct qcom_nand_controller *nandc, bool is_cpu);
> +__le32 *qcom_offset_to_nandc_reg(struct nandc_regs *regs, int offset);
> +int qcom_prep_adm_dma_desc(struct qcom_nand_controller *nandc, bool read,
> +                          int reg_off, const void *vaddr, int size,
> +                       bool flow_control);
> +int qcom_submit_descs(struct qcom_nand_controller *nandc);
> +int qcom_prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> +                               struct dma_chan *chan, unsigned long flags);
> +int qcom_prep_bam_dma_desc_cmd(struct qcom_nand_controller *nandc, bool read,
> +                              int reg_off, const void *vaddr,
> +                       int size, unsigned int flags);
> +int qcom_prep_bam_dma_desc_data(struct qcom_nand_controller *nandc, bool read,
> +                               const void *vaddr,
> +                       int size, unsigned int flags);
> +int qcom_read_reg_dma(struct qcom_nand_controller *nandc, int first,
> +                     int num_regs, unsigned int flags);
> +int qcom_write_reg_dma(struct qcom_nand_controller *nandc, int first,
> +                      int num_regs, unsigned int flags);
> +int qcom_read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +                      const u8 *vaddr, int size, unsigned int flags);
> +int qcom_write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> +                       const u8 *vaddr, int size, unsigned int flags);
> +struct bam_transaction *qcom_alloc_bam_transaction(struct qcom_nand_controller *nandc);
> +void qcom_clear_bam_transaction(struct qcom_nand_controller *nandc);
> +void qcom_nandc_unalloc(struct qcom_nand_controller *nandc);
> +int qcom_nandc_alloc(struct qcom_nand_controller *nandc);
> +void qcom_clear_read_regs(struct qcom_nand_controller *nandc);
> +void qcom_free_bam_transaction(struct qcom_nand_controller *nandc);
> +#endif
> --
> 2.34.1
>
>

General comment: Please take a pause. Start from the scratch by
actually _designing_, what kind of API do you need for you common core
and for NAND and SPI-NOR controllers. Then rework existing driver to
use that API internally. Move the API functions to the common helper.
Add the SPI-NOR driver on top of new _designed_ helper. Just
continuing further on the path of "let's move this and that" will not
lead you to acceptable solution.

-- 
With best wishes
Dmitry

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