Date:	Wed, 30 Jul 2014 05:12:30 +0100
From:	Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
To:	linux-mmc@...r.kernel.org
CC:	Linus Walleij <linus.walleij@...aro.org>,
	Chris Ball <chris@...ntf.net>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Russell King <linux@....linux.org.uk>,
	linux-kernel@...r.kernel.org, agross@...eaurora.org,
	linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v4] mmc: mmci: Add qcom dml support to the driver.

If its not too late, is it possible to queue this patch for v3.17?


---
srini

On 29/07/14 03:50, Srinivas Kandagatla wrote:
> On Qualcomm APQ8064 SOCs, SD card controller has an additional glue
> called DML (Data Mover Local/Lite) to assist dma transfers.
> This hardware needs to be setup before any dma transfer is requested.
> DML itself is not a DMA engine, its just a gule between the SD card
> controller and dma controller.
>
> Most of this code has been ported from qualcomm's 3.4 kernel.
>
> This patch adds the code necessary to intialize the hardware and setup
> before doing any dma transfers.
>
> Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
> ---
> Changes since v3:
>    - moved copyright from Code Aurora to Linux Foundation, as
>      suggested by Stephen B.
>
> Changes since v2:
>    - copied missing memory barriers from 3.4 driver, spotted by Stephen B.
>    - removed unecessary braceses spotted by Stephen B.
>    - copied exact copyright year from 3.4 kernel.
>
> Changes since v1:
>     - Added licence text as spotted by Stephen B.
>     - Simplified dma channel lookup as suggested by Stephen B.
>     - Removed unnecessary parens spotted by Stephen B.
>     - in general some cleanup done.
>
> Changes since RFC:
>      - Moved qcom_dml.* to mmci_qcom_dml.* as suggested by Linus W.
>      - added BAM DMA dependency in Kconfig as suggested by Linus W.
>
>   drivers/mmc/host/Kconfig         |  11 +++
>   drivers/mmc/host/Makefile        |   1 +
>   drivers/mmc/host/mmci.c          |  18 +++-
>   drivers/mmc/host/mmci_qcom_dml.c | 177 +++++++++++++++++++++++++++++++++++++++
>   drivers/mmc/host/mmci_qcom_dml.h |  31 +++++++
>   5 files changed, 237 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/mmc/host/mmci_qcom_dml.c
>   create mode 100644 drivers/mmc/host/mmci_qcom_dml.h
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index a565254..3d9b84d 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -14,6 +14,17 @@ config MMC_ARMMMCI
>
>   	  If unsure, say N.
>
> +config MMC_QCOM_DML
> +	tristate "Qualcomm Data Mover for SD Card Controller"
> +	depends on MMC_ARMMMCI && QCOM_BAM_DMA
> +	default y
> +	help
> +	  This selects the Qualcomm Data Mover lite/local on SD Card controller.
> +	  This option will enable the dma to work correctly, if you are using
> +	  Qcom SOCs and MMC, you would probably need this option to get DMA working.
> +
> +	  if unsure, say N.
> +
>   config MMC_PXA
>   	tristate "Intel PXA25x/26x/27x Multimedia Card Interface support"
>   	depends on ARCH_PXA
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 7f81ddf..344c870 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -3,6 +3,7 @@
>   #
>
>   obj-$(CONFIG_MMC_ARMMMCI)	+= mmci.o
> +obj-$(CONFIG_MMC_QCOM_DML)	+= mmci_qcom_dml.o
>   obj-$(CONFIG_MMC_PXA)		+= pxamci.o
>   obj-$(CONFIG_MMC_MXC)		+= mxcmmc.o
>   obj-$(CONFIG_MMC_MXS)		+= mxs-mmc.o
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index b66b351..9059570 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -43,6 +43,7 @@
>   #include <asm/sizes.h>
>
>   #include "mmci.h"
> +#include "mmci_qcom_dml.h"
>
>   #define DRIVER_NAME "mmci-pl18x"
>
> @@ -74,6 +75,7 @@ static unsigned int fmax = 515633;
>    * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply
>    * @explicit_mclk_control: enable explicit mclk control in driver.
>    * @qcom_fifo: enables qcom specific fifo pio read logic.
> + * @qcom_dml: enables qcom specific dma glue for dma transfers.
>    */
>   struct variant_data {
>   	unsigned int		clkreg;
> @@ -97,6 +99,7 @@ struct variant_data {
>   	bool			pwrreg_nopower;
>   	bool			explicit_mclk_control;
>   	bool			qcom_fifo;
> +	bool			qcom_dml;
>   };
>
>   static struct variant_data variant_arm = {
> @@ -205,6 +208,7 @@ static struct variant_data variant_qcom = {
>   	.f_max			= 208000000,
>   	.explicit_mclk_control	= true,
>   	.qcom_fifo		= true,
> +	.qcom_dml		= true,
>   };
>
>   static int mmci_card_busy(struct mmc_host *mmc)
> @@ -418,6 +422,7 @@ static void mmci_dma_setup(struct mmci_host *host)
>   {
>   	const char *rxname, *txname;
>   	dma_cap_mask_t mask;
> +	struct variant_data *variant = host->variant;
>
>   	host->dma_rx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "rx");
>   	host->dma_tx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "tx");
> @@ -468,6 +473,10 @@ static void mmci_dma_setup(struct mmci_host *host)
>   		if (max_seg_size < host->mmc->max_seg_size)
>   			host->mmc->max_seg_size = max_seg_size;
>   	}
> +
> +	if (variant->qcom_dml && host->dma_rx_channel && host->dma_tx_channel)
> +		if (dml_hw_init(host, host->mmc->parent->of_node))
> +			variant->qcom_dml = false;
>   }
>
>   /*
> @@ -569,6 +578,7 @@ static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
>   	struct dma_async_tx_descriptor *desc;
>   	enum dma_data_direction buffer_dirn;
>   	int nr_sg;
> +	unsigned long flags = DMA_CTRL_ACK;
>
>   	if (data->flags & MMC_DATA_READ) {
>   		conf.direction = DMA_DEV_TO_MEM;
> @@ -593,9 +603,12 @@ static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
>   	if (nr_sg == 0)
>   		return -EINVAL;
>
> +	if (host->variant->qcom_dml)
> +		flags |= DMA_PREP_INTERRUPT;
> +
>   	dmaengine_slave_config(chan, &conf);
>   	desc = dmaengine_prep_slave_sg(chan, data->sg, nr_sg,
> -					    conf.direction, DMA_CTRL_ACK);
> +					    conf.direction, flags);
>   	if (!desc)
>   		goto unmap_exit;
>
> @@ -644,6 +657,9 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
>   	dmaengine_submit(host->dma_desc_current);
>   	dma_async_issue_pending(host->dma_current);
>
> +	if (host->variant->qcom_dml)
> +		dml_start_xfer(host, data);
> +
>   	datactrl |= MCI_DPSM_DMAENABLE;
>
>   	/* Trigger the DMA transfer */
> diff --git a/drivers/mmc/host/mmci_qcom_dml.c b/drivers/mmc/host/mmci_qcom_dml.c
> new file mode 100644
> index 0000000..300ef50
> --- /dev/null
> +++ b/drivers/mmc/host/mmci_qcom_dml.c
> @@ -0,0 +1,177 @@
> +/*
> + *
> + * Copyright (c) 2011, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +#include <linux/of.h>
> +#include <linux/of_dma.h>
> +#include <linux/bitops.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/card.h>
> +#include "mmci.h"
> +
> +/* Registers */
> +#define DML_CONFIG			0x00
> +#define PRODUCER_CRCI_MSK		GENMASK(1, 0)
> +#define PRODUCER_CRCI_DISABLE		0
> +#define PRODUCER_CRCI_X_SEL		BIT(0)
> +#define PRODUCER_CRCI_Y_SEL		BIT(1)
> +#define CONSUMER_CRCI_MSK		GENMASK(3, 2)
> +#define CONSUMER_CRCI_DISABLE		0
> +#define CONSUMER_CRCI_X_SEL		BIT(2)
> +#define CONSUMER_CRCI_Y_SEL		BIT(3)
> +#define PRODUCER_TRANS_END_EN		BIT(4)
> +#define BYPASS				BIT(16)
> +#define DIRECT_MODE			BIT(17)
> +#define INFINITE_CONS_TRANS		BIT(18)
> +
> +#define DML_SW_RESET			0x08
> +#define DML_PRODUCER_START		0x0c
> +#define DML_CONSUMER_START		0x10
> +#define DML_PRODUCER_PIPE_LOGICAL_SIZE	0x14
> +#define DML_CONSUMER_PIPE_LOGICAL_SIZE	0x18
> +#define DML_PIPE_ID			0x1c
> +#define PRODUCER_PIPE_ID_SHFT		0
> +#define PRODUCER_PIPE_ID_MSK		GENMASK(4, 0)
> +#define CONSUMER_PIPE_ID_SHFT		16
> +#define CONSUMER_PIPE_ID_MSK		GENMASK(20, 16)
> +
> +#define DML_PRODUCER_BAM_BLOCK_SIZE	0x24
> +#define DML_PRODUCER_BAM_TRANS_SIZE	0x28
> +
> +/* other definitions */
> +#define PRODUCER_PIPE_LOGICAL_SIZE	4096
> +#define CONSUMER_PIPE_LOGICAL_SIZE	4096
> +
> +#define DML_OFFSET			0x800
> +
> +void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
> +{
> +	u32 config;
> +	void __iomem *base = host->base + DML_OFFSET;
> +
> +	if (data->flags & MMC_DATA_READ) {
> +		/* Read operation: configure DML for producer operation */
> +		/* Set producer CRCI-x and disable consumer CRCI */
> +		config = readl_relaxed(base + DML_CONFIG);
> +		config = (config & ~PRODUCER_CRCI_MSK) | PRODUCER_CRCI_X_SEL;
> +		config = (config & ~CONSUMER_CRCI_MSK) | CONSUMER_CRCI_DISABLE;
> +		writel_relaxed(config, base + DML_CONFIG);
> +
> +		/* Set the Producer BAM block size */
> +		writel_relaxed(data->blksz, base + DML_PRODUCER_BAM_BLOCK_SIZE);
> +
> +		/* Set Producer BAM Transaction size */
> +		writel_relaxed(data->blocks * data->blksz,
> +			       base + DML_PRODUCER_BAM_TRANS_SIZE);
> +		/* Set Producer Transaction End bit */
> +		config = readl_relaxed(base + DML_CONFIG);
> +		config |= PRODUCER_TRANS_END_EN;
> +		writel_relaxed(config, base + DML_CONFIG);
> +		/* Trigger producer */
> +		writel_relaxed(1, base + DML_PRODUCER_START);
> +	} else {
> +		/* Write operation: configure DML for consumer operation */
> +		/* Set consumer CRCI-x and disable producer CRCI*/
> +		config = readl_relaxed(base + DML_CONFIG);
> +		config = (config & ~CONSUMER_CRCI_MSK) | CONSUMER_CRCI_X_SEL;
> +		config = (config & ~PRODUCER_CRCI_MSK) | PRODUCER_CRCI_DISABLE;
> +		writel_relaxed(config, base + DML_CONFIG);
> +		/* Clear Producer Transaction End bit */
> +		config = readl_relaxed(base + DML_CONFIG);
> +		config &= ~PRODUCER_TRANS_END_EN;
> +		writel_relaxed(config, base + DML_CONFIG);
> +		/* Trigger consumer */
> +		writel_relaxed(1, base + DML_CONSUMER_START);
> +	}
> +
> +	/* make sure the dml is configured before dma is triggered */
> +	wmb();
> +}
> +
> +static int of_get_dml_pipe_index(struct device_node *np, const char *name)
> +{
> +	int index;
> +	struct of_phandle_args	dma_spec;
> +
> +	index = of_property_match_string(np, "dma-names", name);
> +
> +	if (index < 0)
> +		return -ENODEV;
> +
> +	if (of_parse_phandle_with_args(np, "dmas", "#dma-cells", index,
> +				       &dma_spec))
> +		return -ENODEV;
> +
> +	if (dma_spec.args_count)
> +		return dma_spec.args[0];
> +
> +	return -ENODEV;
> +}
> +
> +/* Initialize the dml hardware connected to SD Card controller */
> +int dml_hw_init(struct mmci_host *host, struct device_node *np)
> +{
> +	u32 config;
> +	void __iomem *base;
> +	u32 consumer_id, producer_id;
> +
> +	consumer_id = of_get_dml_pipe_index(np, "tx");
> +	producer_id = of_get_dml_pipe_index(np, "rx");
> +
> +	if (producer_id < 0 || consumer_id < 0)
> +		return -ENODEV;
> +
> +	base = host->base + DML_OFFSET;
> +
> +	/* Reset the DML block */
> +	writel_relaxed(1, base + DML_SW_RESET);
> +
> +	/* Disable the producer and consumer CRCI */
> +	config = (PRODUCER_CRCI_DISABLE | CONSUMER_CRCI_DISABLE);
> +	/*
> +	 * Disable the bypass mode. Bypass mode will only be used
> +	 * if data transfer is to happen in PIO mode and don't
> +	 * want the BAM interface to connect with SDCC-DML.
> +	 */
> +	config &= ~BYPASS;
> +	/*
> +	 * Disable direct mode as we don't DML to MASTER the AHB bus.
> +	 * BAM connected with DML should MASTER the AHB bus.
> +	 */
> +	config &= ~DIRECT_MODE;
> +	/*
> +	 * Disable infinite mode transfer as we won't be doing any
> +	 * infinite size data transfers. All data transfer will be
> +	 * of finite data size.
> +	 */
> +	config &= ~INFINITE_CONS_TRANS;
> +	writel_relaxed(config, base + DML_CONFIG);
> +
> +	/*
> +	 * Initialize the logical BAM pipe size for producer
> +	 * and consumer.
> +	 */
> +	writel_relaxed(PRODUCER_PIPE_LOGICAL_SIZE,
> +		       base + DML_PRODUCER_PIPE_LOGICAL_SIZE);
> +	writel_relaxed(CONSUMER_PIPE_LOGICAL_SIZE,
> +		       base + DML_CONSUMER_PIPE_LOGICAL_SIZE);
> +
> +	/* Initialize Producer/consumer pipe id */
> +	writel_relaxed(producer_id | (consumer_id << CONSUMER_PIPE_ID_SHFT),
> +		       base + DML_PIPE_ID);
> +
> +	/* Make sure dml intialization is finished */
> +	mb();
> +
> +	return 0;
> +}
> diff --git a/drivers/mmc/host/mmci_qcom_dml.h b/drivers/mmc/host/mmci_qcom_dml.h
> new file mode 100644
> index 0000000..6e405d0
> --- /dev/null
> +++ b/drivers/mmc/host/mmci_qcom_dml.h
> @@ -0,0 +1,31 @@
> +/*
> + *
> + * Copyright (c) 2011, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +#ifndef __MMC_QCOM_DML_H__
> +#define __MMC_QCOM_DML_H__
> +
> +#ifdef CONFIG_MMC_QCOM_DML
> +int dml_hw_init(struct mmci_host *host, struct device_node *np);
> +void dml_start_xfer(struct mmci_host *host, struct mmc_data *data);
> +#else
> +static inline int dml_hw_init(struct mmci_host *host, struct device_node *np)
> +{
> +	return -ENOSYS;
> +}
> +static inline void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
> +{
> +}
> +#endif /* CONFIG_MMC_QCOM_DML */
> +
> +#endif /* __MMC_QCOM_DML_H__ */
>
--
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