[U-Boot] [PATCH 1/2] dm: spi: soft_spi: support linux way and bug fix

[Peng Fan <van.freenix@gmail.com>]

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. Bug fix
   When doing xfer, should use device->parent, but not device
   When doing bit xfer, should use "!!(tmpdout & 0x80)", but not
   "(tmpdout & 0x80)"
3. Introduce SPI_MASTER_NO_RX and SPI_MASTER_NO_TX to handle
   no rx or no tx case.
4. 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: Jagan Teki <jteki@openedev.com>
Cc: Stefano Babic <sbabic@denx.de>
---
 drivers/spi/soft_spi.c | 75 ++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 57 insertions(+), 18 deletions(-)

diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c
index aa4abcc..9a2b5f2 100644
--- a/drivers/spi/soft_spi.c
+++ b/drivers/spi/soft_spi.c
@@ -26,15 +26,23 @@ 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)
+
+#define UBOOT_COMPAT BIT(0)
+#define LINUX_COMPAT BIT(1)
+
 struct soft_spi_priv {
 	unsigned int mode;
 };
 
 static int soft_spi_scl(struct udevice *dev, int bit)
 {
-	struct soft_spi_platdata *plat = dev->platdata;
+	struct udevice *bus = dev_get_parent(dev);
+	struct soft_spi_platdata *plat = dev_get_platdata(bus);
 
 	dm_gpio_set_value(&plat->sclk, bit);
 
@@ -43,7 +51,8 @@ static int soft_spi_scl(struct udevice *dev, int bit)
 
 static int soft_spi_sda(struct udevice *dev, int bit)
 {
-	struct soft_spi_platdata *plat = dev->platdata;
+	struct udevice *bus = dev_get_parent(dev);
+	struct soft_spi_platdata *plat = dev_get_platdata(bus);
 
 	dm_gpio_set_value(&plat->mosi, bit);
 
@@ -52,7 +61,8 @@ static int soft_spi_sda(struct udevice *dev, int bit)
 
 static int soft_spi_cs_activate(struct udevice *dev)
 {
-	struct soft_spi_platdata *plat = dev->platdata;
+	struct udevice *bus = dev_get_parent(dev);
+	struct soft_spi_platdata *plat = dev_get_platdata(bus);
 
 	dm_gpio_set_value(&plat->cs, 0);
 	dm_gpio_set_value(&plat->sclk, 0);
@@ -63,7 +73,8 @@ static int soft_spi_cs_activate(struct udevice *dev)
 
 static int soft_spi_cs_deactivate(struct udevice *dev)
 {
-	struct soft_spi_platdata *plat = dev->platdata;
+	struct udevice *bus = dev_get_parent(dev);
+	struct soft_spi_platdata *plat = dev_get_platdata(bus);
 
 	dm_gpio_set_value(&plat->cs, 0);
 
@@ -100,8 +111,9 @@ static int soft_spi_release_bus(struct udevice *dev)
 static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
 			 const void *dout, void *din, unsigned long flags)
 {
-	struct soft_spi_priv *priv = dev_get_priv(dev);
-	struct soft_spi_platdata *plat = dev->platdata;
+	struct udevice *bus = dev_get_parent(dev);
+	struct soft_spi_priv *priv = dev_get_priv(bus);
+	struct soft_spi_platdata *plat = dev_get_platdata(bus);
 	uchar		tmpdin  = 0;
 	uchar		tmpdout = 0;
 	const u8	*txd = dout;
@@ -134,14 +146,16 @@ 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)
@@ -202,25 +216,50 @@ static int soft_spi_probe(struct udevice *dev)
 {
 	struct spi_slave *slave = dev_get_parent_priv(dev);
 	struct soft_spi_platdata *plat = dev->platdata;
+	ulong driver_data = dev_get_driver_data(dev);
 	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,
-				 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))
-		return -EINVAL;
+	if (driver_data & UBOOT_COMPAT) {
+		if (gpio_request_by_name(dev, "cs-gpio", 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))
+			return -EINVAL;
+	} else if (driver_data & LINUX_COMPAT) {
+		if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
+					 GPIOD_IS_OUT | cs_flags) ||
+		    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 = "u-boot,soft-spi", .data = UBOOT_COMPAT },
+	{ .compatible = "spi-gpio", .data = LINUX_COMPAT },
 	{ }
 };
 
-- 
2.6.2