[U-Boot] [PATCH 19/55] dm: gpio: Add support for setting a GPIO's pull direction

[Simon Glass]

At present the driver model GPIO API does not support pull-up/pull-down on
input GPIOs. This is required in some cases.

Add this feature to the API with two new methods that drivers can optionally
implement.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

 drivers/gpio/gpio-uclass.c | 31 +++++++++++++++++++++++++++++++
 include/asm-generic/gpio.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 77 insertions(+)

diff --git a/drivers/gpio/gpio-uclass.c b/drivers/gpio/gpio-uclass.c
index 4efda31..c4ba580 100644
--- a/drivers/gpio/gpio-uclass.c
+++ b/drivers/gpio/gpio-uclass.c
@@ -374,6 +374,37 @@ int dm_gpio_set_dir(struct gpio_desc *desc)
 	return dm_gpio_set_dir_flags(desc, desc->flags);
 }
 
+int dm_gpio_set_pull(struct gpio_desc *desc, enum gpio_pull pull)
+{
+	struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
+	int ret;
+
+	ret = check_reserved(desc, "set_pull");
+	if (ret)
+		return ret;
+
+	if (!ops->set_pull)
+		return -ENOSYS;
+
+	return ops->set_pull(desc->dev, desc->offset, pull);
+}
+
+int dm_gpio_get_pull(struct gpio_desc *desc, unsigned offset)
+{
+	struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
+	int ret;
+
+	ret = check_reserved(desc, "get_pull");
+	if (ret)
+		return ret;
+
+	if (!ops->get_pull)
+		return -ENOSYS;
+
+	return ops->get_pull(desc->dev, desc->offset);
+}
+
+
 /**
  * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
  * gpio:	GPIO number
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 0af599f..db5504f 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -126,6 +126,13 @@ struct gpio_desc {
 	 */
 };
 
+/* GPIO pull directions (used for input lines) */
+enum gpio_pull {
+	GPIO_PULL_NONE,
+	GPIO_PULL_DOWN,
+	GPIO_PULL_UP,
+};
+
 /**
  * dm_gpio_is_valid() - Check if a GPIO is valid
  *
@@ -276,6 +283,26 @@ struct dm_gpio_ops {
 	 */
 	int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
 		     struct fdtdec_phandle_args *args);
+
+	/**
+	 * set_pull() - set pull direction
+	 *
+	 * @dev:	Device to adjust
+	 * @offset:	GPIO offset within device
+	 * @pull:	New pull direction
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*set_pull)(struct udevice *dev, unsigned offset,
+			enum gpio_pull pull);
+
+	/**
+	 * get_pull() - get pull direction
+	 *
+	 * @dev:	Device to check
+	 * @offset:	GPIO offset within device
+	 * @return current pull direction or -ve on error
+	 */
+	int (*get_pull)(struct udevice *dev, unsigned offset);
 };
 
 /**
@@ -556,6 +583,25 @@ int dm_gpio_set_dir(struct gpio_desc *desc);
 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
 
 /**
+ * dm_gpio_set_pull() - set pull direction
+ *
+ * @desc:	GPIO description containing device, offset and flags,
+ *		previously returned by gpio_request_by_name()
+ * @pull:	New pull direction
+ * @return 0 if OK, -ve on error
+ */
+int dm_gpio_set_pull(struct gpio_desc *desc, enum gpio_pull pull);
+
+/**
+* dm_gpio_get_pull() - get pull direction
+*
+ * @desc:	GPIO description containing device, offset and flags,
+ *		previously returned by gpio_request_by_name()
+* @return current pull direction or -ve on error
+*/
+int dm_gpio_get_pull(struct gpio_desc *desc, unsigned offset);
+
+/**
  * gpio_get_number() - Get the global GPIO number of a GPIO
  *
  * This should only be used for debugging or interest. It returns the number
-- 
2.4.3.573.g4eafbef