spi: spi-mpc512x-psc: add support for gpio chip selects

Currently the driver only uses one internal chip select.
Add support for gpio chip selects configured by cs-gpios
DT binding.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 25 insertions, 6 deletions

diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 3e490ee7f275..da60f268f74c 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c
@@ -28,6 +28,7 @@
 #include <linux/clk.h>
 #include <linux/spi/spi.h>
 #include <linux/fsl_devices.h>
+#include <linux/gpio.h>
 #include <asm/mpc52xx_psc.h>
 
 struct mpc512x_psc_spi {
@@ -113,7 +114,7 @@ static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
         out_be32(&psc->ccr, ccr);
         mps->bits_per_word = cs->bits_per_word;
 
-        if (mps->cs_control)
+        if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
                 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 }
 
@@ -121,7 +122,7 @@ static void mpc512x_psc_spi_deactivate_cs(struct spi_device *spi)
 {
         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
 
-        if (mps->cs_control)
+        if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
                 mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
 
 }
@@ -278,6 +279,7 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
         struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
         struct mpc512x_psc_spi_cs *cs = spi->controller_state;
         unsigned long flags;
+        int ret;
 
         if (spi->bits_per_word % 8)
                 return -EINVAL;
@@ -286,6 +288,19 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
                 if (!cs)
                         return -ENOMEM;
+
+                if (gpio_is_valid(spi->cs_gpio)) {
+                        ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
+                        if (ret) {
+                                dev_err(&spi->dev, "can't get CS gpio: %d\n",
+                                        ret);
+                                kfree(cs);
+                                return ret;
+                        }
+                        gpio_direction_output(spi->cs_gpio,
+                                        spi->mode & SPI_CS_HIGH ? 0 : 1);
+                }
+
                 spi->controller_state = cs;
         }
 
@@ -319,6 +334,8 @@ static int mpc512x_psc_spi_transfer(struct spi_device *spi,
 
 static void mpc512x_psc_spi_cleanup(struct spi_device *spi)
 {
+        if (gpio_is_valid(spi->cs_gpio))
+                gpio_free(spi->cs_gpio);
         kfree(spi->controller_state);
 }
 
@@ -405,6 +422,11 @@ static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id)
         return IRQ_NONE;
 }
 
+static void mpc512x_spi_cs_control(struct spi_device *spi, bool onoff)
+{
+        gpio_set_value(spi->cs_gpio, onoff);
+}
+
 /* bus_num is used only for the case dev->platform_data == NULL */
 static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
                                               u32 size, unsigned int irq,
@@ -425,12 +447,9 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
         mps->irq = irq;
 
         if (pdata == NULL) {
-                dev_err(dev, "probe called without platform data, no "
-                        "cs_control function will be called\n");
-                mps->cs_control = NULL;
+                mps->cs_control = mpc512x_spi_cs_control;
                 mps->sysclk = 0;
                 master->bus_num = bus_num;
-                master->num_chipselect = 255;
         } else {
                 mps->cs_control = pdata->cs_control;
                 mps->sysclk = pdata->sysclk;