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spi: altera: use regmap-mmio instead of direct mmio register access 

This patch adds support for regmap. It makes preparation for supporting
different ways to access the registers.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/1592531021-11412-2-git-send-email-yilun.xu@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Xu Yilun 2020-06-19 09:43:39 +08:00 committed by Mark Brown
parent 539afdf969
commit 3c6519736e
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
2 changed files with 73 additions and 19 deletions
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1
drivers/spi/Kconfig
View File

@ -59,6 +59,7 @@ comment "SPI Master Controller Drivers"
config SPI_ALTERA
tristate "Altera SPI Controller"
select REGMAP_MMIO
help
This is the driver for the Altera SPI Controller.

91
drivers/spi/spi-altera.c
View File

@ -44,7 +44,6 @@
#define ALTERA_SPI_MAX_CS 32
struct altera_spi {
void __iomem *base;
int irq;
int len;
int count;
@ -54,8 +53,43 @@ struct altera_spi {
/* data buffers */
const unsigned char *tx;
unsigned char *rx;
struct regmap *regmap;
struct device *dev;
};
static const struct regmap_config spi_altera_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.fast_io = true,
};
static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
unsigned int val)
{
int ret;
ret = regmap_write(hw->regmap, reg, val);
if (ret)
dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
reg, val, ret);
return ret;
}
static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
unsigned int *val)
{
int ret;
ret = regmap_read(hw->regmap, reg, val);
if (ret)
dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
return ret;
}
static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
{
return spi_master_get_devdata(sdev->master);
@ -67,12 +101,13 @@ static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
if (is_high) {
hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
} else {
writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
BIT(spi->chip_select));
hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
}
}
@ -99,14 +134,14 @@ static void altera_spi_tx_word(struct altera_spi *hw)
}
}
writel(txd, hw->base + ALTERA_SPI_TXDATA);
altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
}
static void altera_spi_rx_word(struct altera_spi *hw)
{
unsigned int rxd;
rxd = readl(hw->base + ALTERA_SPI_RXDATA);
altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
@ -133,6 +168,7 @@ static int altera_spi_txrx(struct spi_master *master,
struct spi_device *spi, struct spi_transfer *t)
{
struct altera_spi *hw = spi_master_get_devdata(master);
u32 val;
hw->tx = t->tx_buf;
hw->rx = t->rx_buf;
@ -143,7 +179,7 @@ static int altera_spi_txrx(struct spi_master *master,
if (hw->irq >= 0) {
/* enable receive interrupt */
hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
/* send the first byte */
altera_spi_tx_word(hw);
@ -151,9 +187,13 @@ static int altera_spi_txrx(struct spi_master *master,
while (hw->count < hw->len) {
altera_spi_tx_word(hw);
while (!(readl(hw->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
for (;;) {
altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
if (val & ALTERA_SPI_STATUS_RRDY_MSK)
break;
cpu_relax();
}
altera_spi_rx_word(hw);
}
@ -175,7 +215,7 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
} else {
/* disable receive interrupt */
hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
spi_finalize_current_transfer(master);
}
@ -188,7 +228,9 @@ static int altera_spi_probe(struct platform_device *pdev)
struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct altera_spi *hw;
struct spi_master *master;
void __iomem *res;
int err = -ENODEV;
u32 val;
u16 i;
master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
@ -220,19 +262,30 @@ static int altera_spi_probe(struct platform_device *pdev)
master->set_cs = altera_spi_set_cs;
hw = spi_master_get_devdata(master);
hw->dev = &pdev->dev;
/* find and map our resources */
hw->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hw->base)) {
err = PTR_ERR(hw->base);
res = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(res)) {
err = PTR_ERR(res);
goto exit;
}
hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
&spi_altera_config);
if (IS_ERR(hw->regmap)) {
dev_err(&pdev->dev, "regmap mmio init failed\n");
err = PTR_ERR(hw->regmap);
goto exit;
}
/* program defaults into the registers */
hw->imr = 0; /* disable spi interrupts */
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
altr_spi_writel(hw, ALTERA_SPI_STATUS, 0); /* clear status reg */
altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
if (val & ALTERA_SPI_STATUS_RRDY_MSK)
altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
/* irq is optional */
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq >= 0) {
@ -255,7 +308,7 @@ static int altera_spi_probe(struct platform_device *pdev)
}
}
dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
dev_info(&pdev->dev, "base %p, irq %d\n", res, hw->irq);
return 0;
exit: