dm: spi: soft_spi: switch to use linux compatible string

1. Support compatible string "spi-gpio" which is used by Linux
   Linux use different bindings, so use UBOOT_COMPAT and
   LINUX_COMPAT to differentiate them.
2. Introduce SPI_MASTER_NO_RX and SPI_MASTER_NO_TX to handle
   no rx or no tx case.
3. Tested on i.MX6 UltraLite board with 74LV595 spi-gpio chip.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Przemyslaw Marczak <p.marczak@samsung.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/arch/arm/dts/exynos4210-universal_c210.dts b/arch/arm/dts/exynos4210-universal_c210.dts
index 16948c93422725571ab05f2f7ed6e8977cb38571..ad3527ec6f118324e82e0168681c6d2e7774dec2 100644 (file)
--- a/arch/arm/dts/exynos4210-universal_c210.dts
+++ b/arch/arm/dts/exynos4210-universal_c210.dts
@@ -42,11 +42,11 @@
        };
 
        soft-spi {
-               compatible = "u-boot,soft-spi";
-               cs-gpio = <&gpy4 3 0>;
-               sclk-gpio = <&gpy3 1 0>;
-               mosi-gpio = <&gpy3 3 0>;
-               miso-gpio = <&gpy3 0 0>;
+               compatible = "spi-gpio";
+               cs-gpios = <&gpy4 3 0>;
+               gpio-sck = <&gpy3 1 0>;
+               gpio-mosi = <&gpy3 3 0>;
+               gpio-miso = <&gpy3 0 0>;
                spi-delay-us = <1>;
                #address-cells = <1>;
                #size-cells = <0>;

diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c
index 8cdb520608c8d48d69880c31792c5524adcabe42..d23dc81a211edc865b516f07a1e8e3a45f9e4993 100644 (file)
--- a/drivers/spi/soft_spi.c
+++ b/drivers/spi/soft_spi.c
@@ -26,8 +26,12 @@ struct soft_spi_platdata {
        struct gpio_desc mosi;
        struct gpio_desc miso;
        int spi_delay_us;
+       int flags;
 };
 
+#define SPI_MASTER_NO_RX        BIT(0)
+#define SPI_MASTER_NO_TX        BIT(1)
+
 struct soft_spi_priv {
        unsigned int mode;
 };
@@ -139,14 +143,16 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
 
                if (!cpha)
                        soft_spi_scl(dev, 0);
-               soft_spi_sda(dev, !!(tmpdout & 0x80));
+               if ((plat->flags & SPI_MASTER_NO_TX) == 0)
+                       soft_spi_sda(dev, !!(tmpdout & 0x80));
                udelay(plat->spi_delay_us);
                if (cpha)
                        soft_spi_scl(dev, 0);
                else
                        soft_spi_scl(dev, 1);
                tmpdin  <<= 1;
-               tmpdin  |= dm_gpio_get_value(&plat->miso);
+               if ((plat->flags & SPI_MASTER_NO_RX) == 0)
+                       tmpdin  |= dm_gpio_get_value(&plat->miso);
                tmpdout <<= 1;
                udelay(plat->spi_delay_us);
                if (cpha)
@@ -208,24 +214,36 @@ static int soft_spi_probe(struct udevice *dev)
        struct spi_slave *slave = dev_get_parent_priv(dev);
        struct soft_spi_platdata *plat = dev->platdata;
        int cs_flags, clk_flags;
+       int ret;
 
        cs_flags = (slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
        clk_flags = (slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
-       if (gpio_request_by_name(dev, "cs-gpio", 0, &plat->cs,
+
+       if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
                                 GPIOD_IS_OUT | cs_flags) ||
-           gpio_request_by_name(dev, "sclk-gpio", 0, &plat->sclk,
-                                GPIOD_IS_OUT | clk_flags) ||
-           gpio_request_by_name(dev, "mosi-gpio", 0, &plat->mosi,
-                                GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE) ||
-           gpio_request_by_name(dev, "miso-gpio", 0, &plat->miso,
-                                GPIOD_IS_IN))
+           gpio_request_by_name(dev, "gpio-sck", 0, &plat->sclk,
+                                GPIOD_IS_OUT | clk_flags))
+               return -EINVAL;
+
+       ret = gpio_request_by_name(dev, "gpio-mosi", 0, &plat->mosi,
+                                  GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
+       if (ret)
+               plat->flags |= SPI_MASTER_NO_TX;
+
+       ret = gpio_request_by_name(dev, "gpio-miso", 0, &plat->miso,
+                                  GPIOD_IS_IN);
+       if (ret)
+               plat->flags |= SPI_MASTER_NO_RX;
+
+       if ((plat->flags & (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) ==
+           (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX))
                return -EINVAL;
 
        return 0;
 }
 
 static const struct udevice_id soft_spi_ids[] = {
-       { .compatible = "u-boot,soft-spi" },
+       { .compatible = "spi-gpio" },
        { }
 };