Date:	Tue,  8 Jul 2014 09:53:17 +0800
From:	Addy Ke <addy.ke@...k-chips.com>
To:	broonie@...nel.org, heiko@...ech.de, grant.likely@...aro.org,
	robh+dt@...nel.org
Cc:	linux-kernel@...r.kernel.org, linux-spi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
	olof@...om.net, hj@...k-chips.com, kever.yang@...k-chips.com,
	xjq@...k-chips.com, huangtao@...k-chips.com, zyw@...k-chips.com,
	yzq@...k-chips.com, zhenfu.fang@...k-chips.com, cf@...k-chips.com,
	zhangqing@...k-chips.com, hl@...k-chips.com,
	wei.luo@...k-chips.com, Addy Ke <addy.ke@...k-chips.com>
Subject: [PATCH v3 2/2] spi: add driver for Rockchip RK3xxx SoCs integrated SPI

In order to facilitate understanding, rockchip SPI controller IP design
looks similar in its registers to designware. But IC implementation
is different from designware, So we need a dedicated driver for Rockchip
RK3XXX SoCs integrated SPI. The main differences:

- dma request line: rockchip SPI controller have two DMA request line
  for tx and rx.

- Register offset:
                  RK3288        DW

  SPI_CTRLR0      0x0000        0x0000
  SPI_CTRLR1      0x0004        0x0004
  SPI_SSIENR      0x0008        0x0008
  SPI_MWCR        NONE          0x000c
  SPI_SER         0x000c        0x0010
  SPI_BAUDR       0x0010        0x0014
  SPI_TXFTLR      0x0014        0x0018
  SPI_RXFTLR      0x0018        0x001c
  SPI_TXFLR       0x001c        0x0020
  SPI_RXFLR       0x0020        0x0024
  SPI_SR          0x0024        0x0028
  SPI_IPR         0x0028        NONE
  SPI_IMR         0x002c        0x002c
  SPI_ISR         0x0030        0x0030
  SPI_RISR        0x0034        0x0034
  SPI_TXOICR      NONE          0x0038
  SPI_RXOICR      NONE          0x003c
  SPI_RXUICR      NONE          0x0040
  SPI_MSTICR      NONE          0x0044
  SPI_ICR         0x0038        0x0048
  SPI_DMACR       0x003c        0x004c
  SPI_DMATDLR     0x0040        0x0050
  SPI_DMARDLR     0x0044        0x0054
  SPI_TXDR        0x0400        NONE
  SPI_RXDR        0x0800        NONE
  SPI_IDR         NONE          0x0058
  SPI_VERSION     NONE          0x005c
  SPI_DR          NONE          0x0060

- register configuration:
                          RK3288      DW
  - SPI_CTROL0:
    control frame size    bit[5:2]    bit[15:12]
    shift register loop   NONE        bit[11]
    transfer mode         bit[19:18]  bit[9:8]
    frame format          bit[17:16]  bit[5:4]
    data frame size       bit[1:0]    bit[3:0]
 
  For more information, see RK3288 chip manual.

- Wait for idle: Must ensure that the FIFO data has been sent out
  before the next transfer.

Signed-off-by: Addy Ke <addy.ke@...k-chips.com>
---
changes since v1:
- more specific about the differences according to comments from Mark Brown
- not to cast away "const" according to comments from Mark Brown
- add set_cs() operation provided to the core
- change rockchip_spi_hw_init() to get_fifo_len() 
- remove spi_setup() and spi_clean() operations
- remove wait_for_dma(), replaced by calling spi_finalize_current_transfer() when done
- remove wait_for_not_busy(), replaced by setting xfer->delay_usecs
- remove interrupt handler
- call clk_disable_unprepare() if spi_master_resume() failed

changes since v2:
- Kconfig: add "depends on (ARCH_ROCKCHIP || COMPILE_TEST)" for SPI_ROCKCHIP
- use wait_for_idle and do not set xfer->delay_uses suggested by Mark Brown
- master->mode_bits: remove SPI_CS_HIGH bit, according to comments from Jonas Gorski
- remove some log information suggested by Mark Brown
- remove Unneeded semicolon
- add compatible strings for RK3188 and RK3288
- improve differences between RK3288 and DW, provided by IC engineer. 
- fixed some warning checked by "./scripts/checkpatch.pl --strict"

 drivers/spi/Kconfig        |  12 +
 drivers/spi/Makefile       |   1 +
 drivers/spi/spi-rockchip.c | 837 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 850 insertions(+)
 create mode 100644 drivers/spi/spi-rockchip.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 60f2b41..c4e307b 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -375,6 +375,18 @@ config SPI_PXA2XX
 config SPI_PXA2XX_PCI
 	def_tristate SPI_PXA2XX && PCI
 
+config SPI_ROCKCHIP
+	tristate "Rockchip SPI controller driver"
+	depends on (ARCH_ROCKCHIP || COMPILE_TEST)
+	help
+	  This selects a driver for Rockchip SPI controller.
+
+	  If you say yes to this option, support will be included for
+	  RK3066, RK3188 and RK3288 families of SPI controller.
+	  Rockchip SPI controller support DMA transport and PIO mode.
+	  The main usecase of this controller is to use spi flash as boot
+	  device.
+
 config SPI_RSPI
 	tristate "Renesas RSPI/QSPI controller"
 	depends on (SUPERH && SH_DMAE_BASE) || ARCH_SHMOBILE
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index bd79266..361fbf3 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -60,6 +60,7 @@ spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA)	+= spi-pxa2xx-dma.o
 obj-$(CONFIG_SPI_PXA2XX)		+= spi-pxa2xx-platform.o
 obj-$(CONFIG_SPI_PXA2XX_PCI)		+= spi-pxa2xx-pci.o
 obj-$(CONFIG_SPI_QUP)			+= spi-qup.o
+obj-$(CONFIG_SPI_ROCKCHIP)		+= spi-rockchip.o
 obj-$(CONFIG_SPI_RSPI)			+= spi-rspi.o
 obj-$(CONFIG_SPI_S3C24XX)		+= spi-s3c24xx-hw.o
 spi-s3c24xx-hw-y			:= spi-s3c24xx.o
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
new file mode 100644
index 0000000..488a7b8
--- /dev/null
+++ b/drivers/spi/spi-rockchip.c
@@ -0,0 +1,837 @@
+/*
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ * Author: Addy Ke <addy.ke@...k-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/init.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/scatterlist.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/io.h>
+#include <linux/scatterlist.h>
+#include <linux/dmaengine.h>
+
+#define DRIVER_NAME "rockchip-spi"
+
+/* SPI register offsets */
+#define ROCKCHIP_SPI_CTRLR0			0x0000
+#define ROCKCHIP_SPI_CTRLR1			0x0004
+#define ROCKCHIP_SPI_SSIENR			0x0008
+#define ROCKCHIP_SPI_SER			0x000c
+#define ROCKCHIP_SPI_BAUDR			0x0010
+#define ROCKCHIP_SPI_TXFTLR			0x0014
+#define ROCKCHIP_SPI_RXFTLR			0x0018
+#define ROCKCHIP_SPI_TXFLR			0x001c
+#define ROCKCHIP_SPI_RXFLR			0x0020
+#define ROCKCHIP_SPI_SR				0x0024
+#define ROCKCHIP_SPI_IPR			0x0028
+#define ROCKCHIP_SPI_IMR			0x002c
+#define ROCKCHIP_SPI_ISR			0x0030
+#define ROCKCHIP_SPI_RISR			0x0034
+#define ROCKCHIP_SPI_ICR			0x0038
+#define ROCKCHIP_SPI_DMACR			0x003c
+#define ROCKCHIP_SPI_DMATDLR		0x0040
+#define ROCKCHIP_SPI_DMARDLR		0x0044
+#define ROCKCHIP_SPI_TXDR			0x0400
+#define ROCKCHIP_SPI_RXDR			0x0800
+
+/* Bit fields in CTRLR0 */
+#define CR0_DFS_OFFSET				0
+
+#define CR0_CFS_OFFSET				2
+
+#define CR0_SCPH_OFFSET				6
+
+#define CR0_SCPOL_OFFSET			7
+
+#define CR0_CSM_OFFSET				8
+#define CR0_CSM_KEEP				0x0
+/* ss_n be high for half sclk_out cycles */
+#define CR0_CSM_HALF				0X1
+/* ss_n be high for one sclk_out cycle */
+#define CR0_CSM_ONE					0x2
+
+/* ss_n to sclk_out delay */
+#define CR0_SSD_OFFSET				10
+/*
+ * The period between ss_n active and
+ * sclk_out active is half sclk_out cycles
+ */
+#define CR0_SSD_HALF				0x0
+/*
+ * The period between ss_n active and
+ * sclk_out active is one sclk_out cycle
+ */
+#define CR0_SSD_ONE					0x1
+
+#define CR0_EM_OFFSET				11
+#define CR0_EM_LITTLE				0x0
+#define CR0_EM_BIG					0x1
+
+#define CR0_FBM_OFFSET				12
+#define CR0_FBM_MSB					0x0
+#define CR0_FBM_LSB					0x1
+
+#define CR0_BHT_OFFSET				13
+#define CR0_BHT_16BIT				0x0
+#define CR0_BHT_8BIT				0x1
+
+#define CR0_RSD_OFFSET				14
+
+#define CR0_FRF_OFFSET				16
+#define CR0_FRF_SPI					0x0
+#define CR0_FRF_SSP					0x1
+#define CR0_FRF_MICROWIRE			0x2
+
+#define CR0_XFM_OFFSET				18
+#define CR0_XFM_MASK				(0x03 << SPI_XFM_OFFSET)
+#define CR0_XFM_TR					0x0
+#define CR0_XFM_TO					0x1
+#define CR0_XFM_RO					0x2
+
+#define CR0_OPM_OFFSET				20
+#define CR0_OPM_MASTER				0x0
+#define CR0_OPM_SLAVE				0x1
+
+#define CR0_MTM_OFFSET				0x21
+
+/* Bit fields in SER, 2bit */
+#define SER_MASK					0x3
+
+/* Bit fields in SR, 5bit */
+#define SR_MASK						0x1f
+#define SR_BUSY						(1 << 0)
+#define SR_TF_FULL					(1 << 1)
+#define SR_TF_EMPTY					(1 << 2)
+#define SR_RF_EMPTY					(1 << 3)
+#define SR_RF_FULL					(1 << 4)
+
+/* Bit fields in ISR, IMR, ISR, RISR, 5bit */
+#define INT_MASK					0x1f
+#define INT_TF_EMPTY				(1 << 0)
+#define INT_TF_OVERFLOW				(1 << 1)
+#define INT_RF_UNDERFLOW			(1 << 2)
+#define INT_RF_OVERFLOW				(1 << 3)
+#define INT_RF_FULL					(1 << 4)
+
+/* Bit fields in ICR, 4bit */
+#define ICR_MASK					0x0f
+#define ICR_ALL						(1 << 0)
+#define ICR_RF_UNDERFLOW			(1 << 1)
+#define ICR_RF_OVERFLOW				(1 << 2)
+#define ICR_TF_OVERFLOW				(1 << 3)
+
+/* Bit fields in DMACR */
+#define RF_DMA_EN					(1 << 0)
+#define TF_DMA_EN					(1 << 1)
+
+#define RXBUSY						(1 << 0)
+#define TXBUSY						(1 << 1)
+
+enum rockchip_ssi_type {
+	SSI_MOTO_SPI = 0,
+	SSI_TI_SSP,
+	SSI_NS_MICROWIRE,
+};
+
+struct rockchip_spi_dma_data {
+	struct dma_chan *ch;
+	enum dma_transfer_direction direction;
+	dma_addr_t addr;
+};
+
+struct rockchip_spi {
+	struct device *dev;
+	struct spi_master *master;
+
+	struct clk *spiclk;
+	struct clk *apb_pclk;
+
+	void __iomem *regs;
+	/*depth of the FIFO buffer */
+	u32 fifo_len;
+	/* max bus freq supported */
+	u32 max_freq;
+	/* supported slave numbers */
+	enum rockchip_ssi_type type;
+
+	u16 mode;
+	u8 tmode;
+	u8 bpw;
+	u8 n_bytes;
+	unsigned len;
+	u32 speed;
+
+	const void *tx;
+	const void *tx_end;
+	void *rx;
+	void *rx_end;
+
+	u32 state;
+	/* protect state */
+	spinlock_t lock;
+
+	struct completion xfer_completion;
+
+	u32 use_dma;
+	struct sg_table tx_sg;
+	struct sg_table rx_sg;
+	struct rockchip_spi_dma_data dma_rx;
+	struct rockchip_spi_dma_data dma_tx;
+};
+
+static inline void spi_enable_chip(struct rockchip_spi *rs, int enable)
+{
+	writel_relaxed((enable ? 1 : 0), rs->regs + ROCKCHIP_SPI_SSIENR);
+}
+
+static inline void spi_set_clk(struct rockchip_spi *rs, u16 div)
+{
+	writel_relaxed(div, rs->regs + ROCKCHIP_SPI_BAUDR);
+}
+
+static inline void flush_fifo(struct rockchip_spi *rs)
+{
+	while (readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR))
+		readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
+}
+
+static inline void wait_for_idle(struct rockchip_spi *rs)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(5);
+
+	do {
+		if (!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY))
+			return;
+	} while (time_before(jiffies, timeout));
+
+	dev_warn(rs->dev, "spi controller is in busy state!\n");
+}
+
+static u32 get_fifo_len(struct rockchip_spi *rs)
+{
+	u32 fifo;
+
+	for (fifo = 2; fifo < 32; fifo++) {
+		writel_relaxed(fifo, rs->regs + ROCKCHIP_SPI_TXFTLR);
+		if (fifo != readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFTLR))
+			break;
+	}
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_TXFTLR);
+
+	return (fifo == 31) ? 0 : fifo;
+}
+
+static inline u32 tx_max(struct rockchip_spi *rs)
+{
+	u32 tx_left, tx_room;
+
+	tx_left = (rs->tx_end - rs->tx) / rs->n_bytes;
+	tx_room = rs->fifo_len - readl_relaxed(rs->regs + ROCKCHIP_SPI_TXFLR);
+
+	return min(tx_left, tx_room);
+}
+
+static inline u32 rx_max(struct rockchip_spi *rs)
+{
+	u32 rx_left = (rs->rx_end - rs->rx) / rs->n_bytes;
+	u32 rx_room = (u32)readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR);
+
+	return min(rx_left, rx_room);
+}
+
+static void rockchip_spi_set_cs(struct spi_device *spi, bool enable)
+{
+	u32 ser;
+	struct rockchip_spi *rs = spi_master_get_devdata(spi->master);
+
+	ser = readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & SER_MASK;
+
+	/*
+	 * drivers/spi/spi.c:
+	 * static void spi_set_cs(struct spi_device *spi, bool enable)
+	 * {
+	 *		if (spi->mode & SPI_CS_HIGH)
+	 *			enable = !enable;
+	 *
+	 *		if (spi->cs_gpio >= 0)
+	 *			gpio_set_value(spi->cs_gpio, !enable);
+	 *		else if (spi->master->set_cs)
+	 *		spi->master->set_cs(spi, !enable);
+	 * }
+	 *
+	 * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs)
+	 */
+	if (!enable)
+		ser |= 1 << spi->chip_select;
+	else
+		ser &= ~(1 << spi->chip_select);
+
+	writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER);
+}
+
+static int rockchip_spi_prepare_message(struct spi_master *master,
+					struct spi_message *msg)
+{
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+	struct spi_device *spi = msg->spi;
+
+	rs->mode = spi->mode;
+
+	return 0;
+}
+
+static int rockchip_spi_unprepare_message(struct spi_master *master,
+					  struct spi_message *msg)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	/*
+	 * For DMA mode, we need terminate DMA channel and flush
+	 * fifo for the next transfer if DMA thansfer timeout.
+	 * unprepare_message() was called by core if transfer complete
+	 * or timeout. Maybe it is reasonable for error handling here.
+	 */
+	if (rs->use_dma) {
+		if (rs->state & RXBUSY) {
+			dmaengine_terminate_all(rs->dma_rx.ch);
+			flush_fifo(rs);
+		}
+
+		if (rs->state & TXBUSY)
+			dmaengine_terminate_all(rs->dma_tx.ch);
+	}
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+
+	return 0;
+}
+
+static void rockchip_spi_pio_writer(struct rockchip_spi *rs)
+{
+	u32 max = tx_max(rs);
+	u32 txw = 0;
+
+	while (max--) {
+		if (rs->n_bytes == 1)
+			txw = *(u8 *)(rs->tx);
+		else
+			txw = *(u16 *)(rs->tx);
+
+		writel_relaxed(txw, rs->regs + ROCKCHIP_SPI_TXDR);
+		rs->tx += rs->n_bytes;
+	}
+}
+
+static void rockchip_spi_pio_reader(struct rockchip_spi *rs)
+{
+	u32 max = rx_max(rs);
+	u32 rxw;
+
+	while (max--) {
+		rxw = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXDR);
+		if (rs->n_bytes == 1)
+			*(u8 *)(rs->rx) = (u8)rxw;
+		else
+			*(u16 *)(rs->rx) = (u16)rxw;
+		rs->rx += rs->n_bytes;
+	}
+}
+
+static int rockchip_spi_pio_transfer(struct rockchip_spi *rs)
+{
+	int remain = 0;
+
+	do {
+		if (rs->tx) {
+			remain = rs->tx_end - rs->tx;
+			rockchip_spi_pio_writer(rs);
+		}
+
+		if (rs->rx) {
+			remain = rs->rx_end - rs->rx;
+			rockchip_spi_pio_reader(rs);
+		}
+
+		cpu_relax();
+	} while (remain);
+
+	/* If tx, wait until the FIFO data completely. */
+	if (rs->tx)
+		wait_for_idle(rs);
+
+	return 0;
+}
+
+static void rockchip_spi_dma_rxcb(void *data)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = data;
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	rs->state &= ~RXBUSY;
+	if (!(rs->state & TXBUSY))
+		spi_finalize_current_transfer(rs->master);
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+}
+
+static void rockchip_spi_dma_txcb(void *data)
+{
+	unsigned long flags;
+	struct rockchip_spi *rs = data;
+
+	/* Wait until the FIFO data completely. */
+	wait_for_idle(rs);
+
+	spin_lock_irqsave(&rs->lock, flags);
+
+	rs->state &= ~TXBUSY;
+	if (!(rs->state & RXBUSY))
+		spi_finalize_current_transfer(rs->master);
+
+	spin_unlock_irqrestore(&rs->lock, flags);
+}
+
+static int rockchip_spi_dma_transfer(struct rockchip_spi *rs)
+{
+	unsigned long flags;
+	struct dma_slave_config rxconf, txconf;
+	struct dma_async_tx_descriptor *rxdesc, *txdesc;
+
+	spin_lock_irqsave(&rs->lock, flags);
+	rs->state &= ~RXBUSY;
+	rs->state &= ~TXBUSY;
+	spin_unlock_irqrestore(&rs->lock, flags);
+
+	if (rs->rx) {
+		rxconf.direction = rs->dma_rx.direction;
+		rxconf.src_addr = rs->dma_rx.addr;
+		rxconf.src_addr_width = rs->n_bytes;
+		rxconf.src_maxburst = rs->n_bytes;
+		dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
+
+		rxdesc = dmaengine_prep_slave_sg(
+				rs->dma_rx.ch,
+				rs->rx_sg.sgl, rs->rx_sg.nents,
+				rs->dma_rx.direction, DMA_PREP_INTERRUPT);
+
+		rxdesc->callback = rockchip_spi_dma_rxcb;
+		rxdesc->callback_param = rs;
+	}
+
+	if (rs->tx) {
+		txconf.direction = rs->dma_tx.direction;
+		txconf.dst_addr = rs->dma_tx.addr;
+		txconf.dst_addr_width = rs->n_bytes;
+		txconf.dst_maxburst = rs->n_bytes;
+		dmaengine_slave_config(rs->dma_tx.ch, &txconf);
+
+		txdesc = dmaengine_prep_slave_sg(
+				rs->dma_tx.ch,
+				rs->tx_sg.sgl, rs->tx_sg.nents,
+				rs->dma_tx.direction, DMA_PREP_INTERRUPT);
+
+		txdesc->callback = rockchip_spi_dma_txcb;
+		txdesc->callback_param = rs;
+	}
+
+	/* rx must be started before tx due to spi instinct */
+	if (rs->rx) {
+		spin_lock_irqsave(&rs->lock, flags);
+		rs->state |= RXBUSY;
+		spin_unlock_irqrestore(&rs->lock, flags);
+		dmaengine_submit(rxdesc);
+		dma_async_issue_pending(rs->dma_rx.ch);
+	}
+
+	if (rs->tx) {
+		spin_lock_irqsave(&rs->lock, flags);
+		rs->state |= TXBUSY;
+		spin_unlock_irqrestore(&rs->lock, flags);
+		dmaengine_submit(txdesc);
+		dma_async_issue_pending(rs->dma_tx.ch);
+	}
+
+	return 1;
+}
+
+static void rockchip_spi_config(struct rockchip_spi *rs)
+{
+	u32 div = 0;
+	u32 dmacr = 0;
+
+	u32 cr0 = (CR0_BHT_8BIT << CR0_BHT_OFFSET)
+		| (CR0_SSD_ONE << CR0_SSD_OFFSET);
+
+	cr0 |= (rs->n_bytes << CR0_DFS_OFFSET);
+	cr0 |= ((rs->mode & 0x3) << CR0_SCPH_OFFSET);
+	cr0 |= (rs->tmode << CR0_XFM_OFFSET);
+	cr0 |= (rs->type << CR0_FRF_OFFSET);
+
+	if (rs->use_dma) {
+		if (rs->tx)
+			dmacr |= TF_DMA_EN;
+		if (rs->rx)
+			dmacr |= RF_DMA_EN;
+	}
+
+	/* div doesn't support odd number */
+	div = rs->max_freq / rs->speed;
+	div = (div + 1) & 0xfffe;
+
+	spi_enable_chip(rs, 0);
+
+	writel_relaxed(cr0, rs->regs + ROCKCHIP_SPI_CTRLR0);
+
+	writel_relaxed(rs->len - 1, rs->regs + ROCKCHIP_SPI_CTRLR1);
+	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
+	writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
+
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
+	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
+	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);
+
+	spi_set_clk(rs, div);
+
+	dev_dbg(rs->dev, "cr0 0x%x, div %d\n", cr0, div);
+
+	spi_enable_chip(rs, 1);
+}
+
+static int rockchip_spi_transfer_one(
+		struct spi_master *master,
+		struct spi_device *spi,
+		struct spi_transfer *xfer)
+{
+	int ret = 0;
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	WARN_ON((readl_relaxed(rs->regs + ROCKCHIP_SPI_SR) & SR_BUSY));
+
+	if (!xfer->tx_buf && !xfer->rx_buf) {
+		dev_err(rs->dev, "No buffer for transfer\n");
+		return -EINVAL;
+	}
+
+	rs->speed = xfer->speed_hz;
+	rs->bpw = xfer->bits_per_word;
+	rs->n_bytes = rs->bpw >> 3;
+
+	rs->tx = xfer->tx_buf;
+	rs->tx_end = rs->tx + xfer->len;
+	rs->rx = xfer->rx_buf;
+	rs->rx_end = rs->rx + xfer->len;
+	rs->len = xfer->len;
+
+	rs->tx_sg = xfer->tx_sg;
+	rs->rx_sg = xfer->rx_sg;
+
+	if (rs->tx && rs->rx)
+		rs->tmode = CR0_XFM_TR;
+	else if (rs->tx)
+		rs->tmode = CR0_XFM_TO;
+	else if (rs->rx)
+		rs->tmode = CR0_XFM_RO;
+
+	if (master->can_dma && master->can_dma(master, spi, xfer))
+		rs->use_dma = 1;
+	else
+		rs->use_dma = 0;
+
+	rockchip_spi_config(rs);
+
+	if (rs->use_dma)
+		ret = rockchip_spi_dma_transfer(rs);
+	else
+		ret = rockchip_spi_pio_transfer(rs);
+
+	return ret;
+}
+
+static bool rockchip_spi_can_dma(struct spi_master *master,
+				 struct spi_device *spi,
+				 struct spi_transfer *xfer)
+{
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	return (xfer->len > rs->fifo_len);
+}
+
+static int rockchip_spi_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct rockchip_spi *rs;
+	struct spi_master *master;
+	struct resource *mem;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct rockchip_spi));
+	if (!master)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, master);
+
+	rs = spi_master_get_devdata(master);
+	memset(rs, 0, sizeof(struct rockchip_spi));
+
+	/* Get basic io resource and map it */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rs->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(rs->regs)) {
+		dev_err(&pdev->dev, "Failed to map SPI region\n");
+		ret =  PTR_ERR(rs->regs);
+		goto err_ioremap_resource;
+	}
+
+	rs->apb_pclk = devm_clk_get(&pdev->dev, "apb_pclk");
+	if (IS_ERR(rs->apb_pclk)) {
+		dev_err(&pdev->dev, "Failed to get apb_pclk\n");
+		ret = PTR_ERR(rs->apb_pclk);
+		goto err_ioremap_resource;
+	}
+
+	rs->spiclk = devm_clk_get(&pdev->dev, "spiclk");
+	if (IS_ERR(rs->spiclk)) {
+		dev_err(&pdev->dev, "Failed to get spi_pclk\n");
+		ret = PTR_ERR(rs->spiclk);
+		goto err_ioremap_resource;
+	}
+
+	ret = clk_prepare_enable(rs->apb_pclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable apb_pclk\n");
+		goto err_ioremap_resource;
+	}
+
+	ret = clk_prepare_enable(rs->spiclk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to enable spi_clk\n");
+		goto err_spiclk_enable;
+	}
+
+	spi_enable_chip(rs, 0);
+
+	rs->type = SSI_MOTO_SPI;
+	rs->master = master;
+	rs->dev = &pdev->dev;
+	rs->max_freq = clk_get_rate(rs->spiclk);
+
+	rs->fifo_len = get_fifo_len(rs);
+	if (!rs->fifo_len) {
+		dev_err(&pdev->dev, "Failed to get fifo length\n");
+		goto err_get_fifo_len;
+	}
+
+	spin_lock_init(&rs->lock);
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	master->auto_runtime_pm = true;
+	master->bus_num = pdev->id;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LOOP;
+	master->num_chipselect = 2;
+	master->dev.of_node = pdev->dev.of_node;
+	master->bits_per_word_mask = SPI_BPW_MASK(16) | SPI_BPW_MASK(8);
+
+	master->set_cs = rockchip_spi_set_cs;
+	master->prepare_message = rockchip_spi_prepare_message;
+	master->unprepare_message = rockchip_spi_unprepare_message;
+	master->transfer_one = rockchip_spi_transfer_one;
+
+	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
+	if (!rs->dma_tx.ch)
+		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
+
+	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
+	if (!rs->dma_rx.ch) {
+		if (rs->dma_tx.ch) {
+			dma_release_channel(rs->dma_tx.ch);
+			rs->dma_tx.ch = NULL;
+		}
+		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
+	}
+
+	if (rs->dma_tx.ch && rs->dma_rx.ch) {
+		rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR);
+		rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR);
+		rs->dma_tx.direction = DMA_MEM_TO_DEV;
+		rs->dma_tx.direction = DMA_DEV_TO_MEM;
+
+		master->can_dma = rockchip_spi_can_dma;
+		master->dma_tx = rs->dma_tx.ch;
+		master->dma_rx = rs->dma_rx.ch;
+	}
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register master\n");
+		goto err_register_master;
+	}
+
+	return 0;
+
+err_register_master:
+	if (rs->dma_tx.ch)
+		dma_release_channel(rs->dma_tx.ch);
+	if (rs->dma_rx.ch)
+		dma_release_channel(rs->dma_rx.ch);
+err_get_fifo_len:
+	clk_disable_unprepare(rs->spiclk);
+err_spiclk_enable:
+	clk_disable_unprepare(rs->apb_pclk);
+err_ioremap_resource:
+	spi_master_put(master);
+
+	return ret;
+}
+
+static int rockchip_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	pm_runtime_disable(&pdev->dev);
+
+	clk_disable_unprepare(rs->spiclk);
+	clk_disable_unprepare(rs->apb_pclk);
+
+	if (rs->dma_tx.ch)
+		dma_release_channel(rs->dma_tx.ch);
+	if (rs->dma_rx.ch)
+		dma_release_channel(rs->dma_rx.ch);
+
+	spi_master_put(master);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int rockchip_spi_suspend(struct device *dev)
+{
+	int ret = 0;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	ret = spi_master_suspend(rs->master);
+	if (ret)
+		return ret;
+
+	if (!pm_runtime_suspended(dev)) {
+		clk_disable_unprepare(rs->spiclk);
+		clk_disable_unprepare(rs->apb_pclk);
+	}
+
+	return ret;
+}
+
+static int rockchip_spi_resume(struct device *dev)
+{
+	int ret = 0;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	if (!pm_runtime_suspended(dev)) {
+		ret = clk_prepare_enable(rs->apb_pclk);
+		if (ret < 0)
+			return ret;
+
+		ret = clk_prepare_enable(rs->spiclk);
+		if (ret < 0) {
+			clk_disable_unprepare(rs->apb_pclk);
+			return ret;
+		}
+	}
+
+	ret = spi_master_resume(rs->master);
+	if (ret < 0) {
+		clk_disable_unprepare(rs->spiclk);
+		clk_disable_unprepare(rs->apb_pclk);
+	}
+
+	return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+#ifdef CONFIG_PM_RUNTIME
+static int rockchip_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	clk_disable_unprepare(rs->spiclk);
+	clk_disable_unprepare(rs->apb_pclk);
+
+	return 0;
+}
+
+static int rockchip_spi_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct rockchip_spi *rs = spi_master_get_devdata(master);
+
+	ret = clk_prepare_enable(rs->apb_pclk);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(rs->spiclk);
+	if (ret)
+		clk_disable_unprepare(rs->apb_pclk);
+
+	return ret;
+}
+#endif /* CONFIG_PM_RUNTIME */
+
+static const struct dev_pm_ops rockchip_spi_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(rockchip_spi_suspend, rockchip_spi_resume)
+	SET_RUNTIME_PM_OPS(rockchip_spi_runtime_suspend,
+			   rockchip_spi_runtime_resume, NULL)
+};
+
+static const struct of_device_id rockchip_spi_dt_match[] = {
+	{ .compatible = "rockchip,rk3066-spi", },
+	{ .compatible = "rockchip,rk3188-spi", },
+	{ .compatible = "rockchip,rk3288-spi", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rockchip_spi_dt_match);
+
+static struct platform_driver rockchip_spi_driver = {
+	.driver = {
+		.name	= DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.pm = &rockchip_spi_pm,
+		.of_match_table = of_match_ptr(rockchip_spi_dt_match),
+	},
+	.probe = rockchip_spi_probe,
+	.remove = rockchip_spi_remove,
+};
+
+module_platform_driver(rockchip_spi_driver);
+
+MODULE_AUTHOR("Addy Ke <addy.ke@...k-chips.com>");
+MODULE_DESCRIPTION("ROCKCHIP SPI Controller Driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.3.2


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