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>

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 357810d..4e4513a 100644 (file)
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -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.
 

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index aa9d1a2..b215bdf 100644 (file)
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -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: