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spi/fsl-dspi: Convert to use regmap and add big-endian support
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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>
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Chao Fu authored and Mark Brown committed Feb 16, 2014
1 parent 38dbfb5 commit 1acbdeb
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Showing 3 changed files with 56 additions and 27 deletions.
2 changes: 2 additions & 0 deletions Documentation/devicetree/bindings/spi/spi-fsl-dspi.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ Required properties:
- pinctrl-names: must contain a "default" entry.
- spi-num-chipselects : the number of the chipselect signals.
- bus-num : the slave chip chipselect signal number.
- big-endian : if DSPI modudle is big endian, the bool will be set in node.
Example:

dspi0@4002c000 {
Expand All @@ -24,6 +25,7 @@ dspi0@4002c000 {
bus-num = <0>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_dspi0_1>;
big-endian;
status = "okay";

sflash: at26df081a@0 {
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1 change: 1 addition & 0 deletions drivers/spi/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -270,6 +270,7 @@ 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
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80 changes: 53 additions & 27 deletions drivers/spi/spi-fsl-dspi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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;

Expand All @@ -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,
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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++;
}

Expand All @@ -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++;
Expand Down Expand Up @@ -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);

Expand All @@ -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:
Expand All @@ -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)
Expand Down Expand Up @@ -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 {
Expand Down Expand Up @@ -435,12 +441,20 @@ 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));
Expand Down Expand Up @@ -475,12 +489,24 @@ 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");
Expand Down

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