spi/fsl-dspi: Convert to use regmap and add big-endian support

Freescale DSPI module will have two endianess in different platform,
but ARM is little endian. So when DSPI in big endian, core in little endian,
readl and writel can not adjust R/W register in this condition.
This patch will remove general readl/writel, and import regmap mechanism.
Data endian will be transfered in regmap APIs.

Documents: dspi add bool "big-endian" in dts node if DSPI module
work in big endian.

Signed-off-by: Chao Fu <b44548@freescale.com>
Reviewed-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
(cherry picked from commit 1acbdeb92c87fc18eade0815dedc257fe45b88b7)
Change-Id: I60e630bb18a2101af3154633bbe5824a52ac45f2
Reviewed-on: http://git.am.freescale.net:8181/20086
Reviewed-by: Zhengxiong Jin <Jason.Jin@freescale.com>
Tested-by: Zhengxiong Jin <Jason.Jin@freescale.com>

2 files changed, 54 insertions, 27 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index c463d36..21bf181 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -264,6 +264,7 @@ config SPI_FSL_SPI
 config SPI_FSL_DSPI
 	tristate "Freescale DSPI controller"
 	select SPI_BITBANG
+	select REGMAP_MMIO
 	depends on SOC_VF610 || COMPILE_TEST
 	help
 	  This enables support for the Freescale DSPI controller in master
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index a253920..286f51d 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -18,6 +18,7 @@
 #include <linux/interrupt.h>
 #include <linux/errno.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/io.h>
@@ -108,7 +109,7 @@ struct fsl_dspi {
 	struct spi_bitbang	bitbang;
 	struct platform_device	*pdev;
 
-	void __iomem		*base;
+	struct regmap		*regmap;
 	int			irq;
 	struct clk 		*clk;
 
@@ -129,18 +130,11 @@ struct fsl_dspi {
 
 static inline int is_double_byte_mode(struct fsl_dspi *dspi)
 {
-	return ((readl(dspi->base + SPI_CTAR(dspi->cs)) & SPI_FRAME_BITS_MASK)
-			== SPI_FRAME_BITS(8)) ? 0 : 1;
-}
+	unsigned int val;
 
-static void set_bit_mode(struct fsl_dspi *dspi, unsigned char bits)
-{
-	u32 temp;
+	regmap_read(dspi->regmap, SPI_CTAR(dspi->cs), &val);
 
-	temp = readl(dspi->base + SPI_CTAR(dspi->cs));
-	temp &= ~SPI_FRAME_BITS_MASK;
-	temp |= SPI_FRAME_BITS(bits);
-	writel(temp, dspi->base + SPI_CTAR(dspi->cs));
+	return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1;
 }
 
 static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
@@ -188,7 +182,8 @@ static int dspi_transfer_write(struct fsl_dspi *dspi)
 	 */
 	if (tx_word && (dspi->len == 1)) {
 		dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
-		set_bit_mode(dspi, 8);
+		regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
+				SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
 		tx_word = 0;
 	}
 
@@ -238,7 +233,8 @@ static int dspi_transfer_write(struct fsl_dspi *dspi)
 			dspi_pushr |= SPI_PUSHR_CTCNT; /* clear counter */
 		}
 
-		writel(dspi_pushr, dspi->base + SPI_PUSHR);
+		regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
+
 		tx_count++;
 	}
 
@@ -253,17 +249,23 @@ static int dspi_transfer_read(struct fsl_dspi *dspi)
 	while ((dspi->rx < dspi->rx_end)
 			&& (rx_count < DSPI_FIFO_SIZE)) {
 		if (rx_word) {
+			unsigned int val;
+
 			if ((dspi->rx_end - dspi->rx) == 1)
 				break;
 
-			d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR));
+			regmap_read(dspi->regmap, SPI_POPR, &val);
+			d = SPI_POPR_RXDATA(val);
 
 			if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
 				*(u16 *)dspi->rx = d;
 			dspi->rx += 2;
 
 		} else {
-			d = SPI_POPR_RXDATA(readl(dspi->base + SPI_POPR));
+			unsigned int val;
+
+			regmap_read(dspi->regmap, SPI_POPR, &val);
+			d = SPI_POPR_RXDATA(val);
 			if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
 				*(u8 *)dspi->rx = d;
 			dspi->rx++;
@@ -295,13 +297,13 @@ static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t)
 	if (!dspi->tx)
 		dspi->dataflags |= TRAN_STATE_TX_VOID;
 
-	writel(dspi->cur_chip->mcr_val, dspi->base + SPI_MCR);
-	writel(dspi->cur_chip->ctar_val, dspi->base + SPI_CTAR(dspi->cs));
-	writel(SPI_RSER_EOQFE, dspi->base + SPI_RSER);
+	regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
+	regmap_write(dspi->regmap, SPI_CTAR(dspi->cs), dspi->cur_chip->ctar_val);
+	regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
 
 	if (t->speed_hz)
-		writel(dspi->cur_chip->ctar_val,
-				dspi->base + SPI_CTAR(dspi->cs));
+		regmap_write(dspi->regmap, SPI_CTAR(dspi->cs),
+				dspi->cur_chip->ctar_val);
 
 	dspi_transfer_write(dspi);
 
@@ -315,7 +317,9 @@ static int dspi_txrx_transfer(struct spi_device *spi, struct spi_transfer *t)
 static void dspi_chipselect(struct spi_device *spi, int value)
 {
 	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
-	u32 pushr = readl(dspi->base + SPI_PUSHR);
+	unsigned int pushr;
+
+	regmap_read(dspi->regmap, SPI_PUSHR, &pushr);
 
 	switch (value) {
 	case BITBANG_CS_ACTIVE:
@@ -326,7 +330,7 @@ static void dspi_chipselect(struct spi_device *spi, int value)
 		break;
 	}
 
-	writel(pushr, dspi->base + SPI_PUSHR);
+	regmap_write(dspi->regmap, SPI_PUSHR, pushr);
 }
 
 static int dspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
@@ -382,13 +386,15 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 {
 	struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
 
-	writel(SPI_SR_EOQF, dspi->base + SPI_SR);
+	regmap_write(dspi->regmap, SPI_SR, SPI_SR_EOQF);
 
 	dspi_transfer_read(dspi);
 
 	if (!dspi->len) {
 		if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
-			set_bit_mode(dspi, 16);
+			regmap_update_bits(dspi->regmap, SPI_CTAR(dspi->cs),
+				SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(16));
+
 		dspi->waitflags = 1;
 		wake_up_interruptible(&dspi->waitq);
 	} else {
@@ -434,12 +440,20 @@ static const struct dev_pm_ops dspi_pm = {
 	SET_SYSTEM_SLEEP_PM_OPS(dspi_suspend, dspi_resume)
 };
 
+static struct regmap_config dspi_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x88,
+};
+
 static int dspi_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct spi_master *master;
 	struct fsl_dspi *dspi;
 	struct resource *res;
+	void __iomem *base;
 	int ret = 0, cs_num, bus_num;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
@@ -474,12 +488,24 @@ static int dspi_probe(struct platform_device *pdev)
 	master->bus_num = bus_num;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	dspi->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(dspi->base)) {
-		ret = PTR_ERR(dspi->base);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
 		goto out_master_put;
 	}
 
+	dspi_regmap_config.lock_arg = dspi;
+	dspi_regmap_config.val_format_endian =
+		of_property_read_bool(np, "big-endian")
+			? REGMAP_ENDIAN_BIG : REGMAP_ENDIAN_DEFAULT;
+	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "dspi", base,
+						&dspi_regmap_config);
+	if (IS_ERR(dspi->regmap)) {
+		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
+				PTR_ERR(dspi->regmap));
+		return PTR_ERR(dspi->regmap);
+	}
+
 	dspi->irq = platform_get_irq(pdev, 0);
 	if (dspi->irq < 0) {
 		dev_err(&pdev->dev, "can't get platform irq\n");