dm: gpio: Implement open drain for MPC85XX GPIO

This patch implements the open-drain setting feature for the MPC85XX
GPIO controller.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: York Sun <york.sun@nxp.com>

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b674a47..8595e2e 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -193,9 +193,9 @@ config MPC85XX_GPIO
          configurable to match the actual GPIO count of the SoC (e.g. the
          32/32/23 banks of the P1022 SoC).
 
-         The standard functions of input/output mode, and output value setting
-         are supported; the open-drain capability of the controller is not
-         supported yet.
+         Aside from the standard functions of input/output mode, and output
+         value setting, the open-drain feature, which can configure individual
+         GPIOs to work as open-drain outputs, is supported.
 
          The driver has been tested on MPC85XX, but it is likely that other
          PowerQUICC III devices will work as well.

diff --git a/drivers/gpio/mpc85xx_gpio.c b/drivers/gpio/mpc85xx_gpio.c
index 17755df..04773e2 100644 (file)
--- a/drivers/gpio/mpc85xx_gpio.c
+++ b/drivers/gpio/mpc85xx_gpio.c
@@ -73,6 +73,25 @@ static inline void mpc85xx_gpio_set_high(struct ccsr_gpio *base, u32 gpios)
        setbits_be32(&base->gpdir, gpios);
 }
 
+static inline int mpc85xx_gpio_open_drain_val(struct ccsr_gpio *base, u32 mask)
+{
+       return in_be32(&base->gpodr) & mask;
+}
+
+static inline void mpc85xx_gpio_open_drain_on(struct ccsr_gpio *base, u32
+                                             gpios)
+{
+       /* GPODR register 1 -> open drain on */
+       setbits_be32(&base->gpodr, gpios);
+}
+
+static inline void mpc85xx_gpio_open_drain_off(struct ccsr_gpio *base,
+                                              u32 gpios)
+{
+       /* GPODR register 0 -> open drain off (actively driven) */
+       clrbits_be32(&base->gpodr, gpios);
+}
+
 static int mpc85xx_gpio_direction_input(struct udevice *dev, unsigned gpio)
 {
        struct mpc85xx_gpio_data *data = dev_get_priv(dev);
@@ -115,6 +134,26 @@ static int mpc85xx_gpio_get_value(struct udevice *dev, unsigned gpio)
        }
 }
 
+static int mpc85xx_gpio_get_open_drain(struct udevice *dev, unsigned gpio)
+{
+       struct mpc85xx_gpio_data *data = dev_get_priv(dev);
+
+       return !!mpc85xx_gpio_open_drain_val(data->base, gpio_mask(gpio));
+}
+
+static int mpc85xx_gpio_set_open_drain(struct udevice *dev, unsigned gpio,
+                                      int value)
+{
+       struct mpc85xx_gpio_data *data = dev_get_priv(dev);
+
+       if (value) {
+               mpc85xx_gpio_open_drain_on(data->base, gpio_mask(gpio));
+       } else {
+               mpc85xx_gpio_open_drain_off(data->base, gpio_mask(gpio));
+       }
+       return 0;
+}
+
 static int mpc85xx_gpio_get_function(struct udevice *dev, unsigned gpio)
 {
        struct mpc85xx_gpio_data *data = dev_get_priv(dev);
@@ -168,6 +207,8 @@ static const struct dm_gpio_ops gpio_mpc85xx_ops = {
        .direction_output       = mpc85xx_gpio_direction_output,
        .get_value              = mpc85xx_gpio_get_value,
        .set_value              = mpc85xx_gpio_set_value,
+       .get_open_drain         = mpc85xx_gpio_get_open_drain,
+       .set_open_drain         = mpc85xx_gpio_set_open_drain,
        .get_function           = mpc85xx_gpio_get_function,
 };