[PATCH 1/5] pinctrl: Add core function pinmux_gpio_get_direction

[Paul Cercueil <paul@crapouillou.net>]

Right now there is a core function to set the direction (input or output)
of a GPIO, pinmux_gpio_set_direction(). This function is provided to the
consumers with two wrappers, pinctrl_gpio_direction_input() /
pinctrl_gpio_direction_output(). Typically, these functions are used
within GPIO drivers, where the .direction_input/.direction_output
callbacks of the "gpio_chip" simply call into these pinctrl functions.

However, until now there was no corresponding pinmux_get_direction()
core function (nor pinctrl_gpio_get_direction), which means that it was
not possible to call into the pinctrl subsystem for the .get_direction
callback of the "gpio_chip".

Here, we introduce the pinmux_gpio_get_direction() core function, as
well as the .gpio_get_direction callback in the pinmux_ops structure.
Now it's up to the pinctrl drivers to implement that callback.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 drivers/pinctrl/pinmux.c       | 17 +++++++++++++++++
 drivers/pinctrl/pinmux.h       |  3 +++
 include/linux/pinctrl/pinmux.h |  5 +++++
 3 files changed, 25 insertions(+)

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
index b8e9bda8ec98..e502a4f5be6f 100644
--- a/drivers/pinctrl/pinmux.c
+++ b/drivers/pinctrl/pinmux.c
@@ -291,6 +291,23 @@ int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
 	return ret;
 }
 
+int pinmux_gpio_get_direction(struct pinctrl_dev *pctldev,
+			      struct pinctrl_gpio_range *range,
+			      unsigned int pin)
+{
+	const struct pinmux_ops *ops;
+	int ret;
+
+	ops = pctldev->desc->pmxops;
+
+	if (ops->gpio_get_direction)
+		ret = ops->gpio_get_direction(pctldev, range, pin);
+	else
+		ret = -ENXIO;
+
+	return ret;
+}
+
 static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
 					const char *function)
 {
diff --git a/drivers/pinctrl/pinmux.h b/drivers/pinctrl/pinmux.h
index a331fcdbedd9..8cdab9e71870 100644
--- a/drivers/pinctrl/pinmux.h
+++ b/drivers/pinctrl/pinmux.h
@@ -24,6 +24,9 @@ void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
 int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
 			  struct pinctrl_gpio_range *range,
 			  unsigned pin, bool input);
+int pinmux_gpio_get_direction(struct pinctrl_dev *pctldev,
+			  struct pinctrl_gpio_range *range,
+			  unsigned pin);
 
 int pinmux_map_to_setting(const struct pinctrl_map *map,
 			  struct pinctrl_setting *setting);
diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h
index ace60d775b20..b3e73deffb49 100644
--- a/include/linux/pinctrl/pinmux.h
+++ b/include/linux/pinctrl/pinmux.h
@@ -56,6 +56,8 @@ struct pinctrl_dev;
  *	depending on whether the GPIO is configured as input or output,
  *	a direction selector function may be implemented as a backing
  *	to the GPIO controllers that need pin muxing.
+ * @gpio_get_direction: Return the direction (input or output) of the given
+ *	GPIO.
  * @strict: do not allow simultaneous use of the same pin for GPIO and another
  *	function. Check both gpio_owner and mux_owner strictly before approving
  *	the pin request.
@@ -82,6 +84,9 @@ struct pinmux_ops {
 				   struct pinctrl_gpio_range *range,
 				   unsigned offset,
 				   bool input);
+	int (*gpio_get_direction) (struct pinctrl_dev *pctrldev,
+				   struct pinctrl_gpio_range *range,
+				   unsigned int offset);
 	bool strict;
 };
 
-- 
2.11.0