pinctrl: gpio: Add callback for configuring pin as GPIO

Add callback to configure, and de-configure, pin as a GPIO on the
pin controller side. This matches similar functionality in Linux
and aims to replace the ad-hoc implementations present in U-Boot.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Alex Kiernan <alex.kiernan@gmail.com>
Cc: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Cc: Eugeniu Rosca <roscaeugeniu@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick DELAUNAY <patrick.delaunay@st.com>
Cc: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Cc: Simon Glass <sjg@chromium.org>

2 files changed, 140 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-uclass.c b/drivers/pinctrl/pinctrl-uclass.c
index f01bc77a576..5b1cd29d862 100644
--- a/drivers/pinctrl/pinctrl-uclass.c
+++ b/drivers/pinctrl/pinctrl-uclass.c
@@ -172,6 +172,102 @@ static int pinconfig_post_bind(struct udevice *dev)
 }
 #endif
 
+static int
+pinctrl_gpio_get_pinctrl_and_offset(struct udevice *dev, unsigned offset,
+				    struct udevice **pctldev,
+				    unsigned int *pin_selector)
+{
+	struct ofnode_phandle_args args;
+	unsigned gpio_offset, pfc_base, pfc_pins;
+	int ret;
+
+	ret = dev_read_phandle_with_args(dev, "gpio-ranges", NULL, 3,
+					 0, &args);
+	if (ret) {
+		dev_dbg(dev, "%s: dev_read_phandle_with_args: err=%d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_PINCTRL,
+					  args.node, pctldev);
+	if (ret) {
+		dev_dbg(dev,
+			"%s: uclass_get_device_by_of_offset failed: err=%d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	gpio_offset = args.args[0];
+	pfc_base = args.args[1];
+	pfc_pins = args.args[2];
+
+	if (offset < gpio_offset || offset > gpio_offset + pfc_pins) {
+		dev_dbg(dev,
+			"%s: GPIO can not be mapped to pincontrol pin\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	offset -= gpio_offset;
+	offset += pfc_base;
+	*pin_selector = offset;
+
+	return 0;
+}
+
+/**
+ * pinctrl_gpio_request() - request a single pin to be used as GPIO
+ *
+ * @dev: GPIO peripheral device
+ * @offset: the GPIO pin offset from the GPIO controller
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_gpio_request(struct udevice *dev, unsigned offset)
+{
+	const struct pinctrl_ops *ops;
+	struct udevice *pctldev;
+	unsigned int pin_selector;
+	int ret;
+
+	ret = pinctrl_gpio_get_pinctrl_and_offset(dev, offset,
+						  &pctldev, &pin_selector);
+	if (ret)
+		return ret;
+
+	ops = pinctrl_get_ops(pctldev);
+	if (!ops || !ops->gpio_request_enable)
+		return -ENOTSUPP;
+
+	return ops->gpio_request_enable(pctldev, pin_selector);
+}
+
+/**
+ * pinctrl_gpio_free() - free a single pin used as GPIO
+ *
+ * @dev: GPIO peripheral device
+ * @offset: the GPIO pin offset from the GPIO controller
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_gpio_free(struct udevice *dev, unsigned offset)
+{
+	const struct pinctrl_ops *ops;
+	struct udevice *pctldev;
+	unsigned int pin_selector;
+	int ret;
+
+	ret = pinctrl_gpio_get_pinctrl_and_offset(dev, offset,
+						  &pctldev, &pin_selector);
+	if (ret)
+		return ret;
+
+	ops = pinctrl_get_ops(pctldev);
+	if (!ops || !ops->gpio_disable_free)
+		return -ENOTSUPP;
+
+	return ops->gpio_disable_free(pctldev, pin_selector);
+}
+
 /**
  * pinctrl_select_state_simple() - simple implementation of pinctrl_select_state
  *
diff --git a/include/dm/pinctrl.h b/include/dm/pinctrl.h
index 63a7d55b888..e7b8ad90787 100644
--- a/include/dm/pinctrl.h
+++ b/include/dm/pinctrl.h
@@ -70,6 +70,13 @@ struct pinconf_param {
  * @set_state_simple: do needed pinctrl operations for a peripherl @periph.
  *	(necessary for pinctrl_simple)
  * @get_pin_muxing: display the muxing of a given pin.
+ * @gpio_request_enable: requests and enables GPIO on a certain pin.
+ *	Implement this only if you can mux every pin individually as GPIO. The
+ *	affected GPIO range is passed along with an offset(pin number) into that
+ *	specific GPIO range - function selectors and pin groups are orthogonal
+ *	to this, the core will however make sure the pins do not collide.
+ * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
+ *	@gpio_request_enable
  */
 struct pinctrl_ops {
 	int (*get_pins_count)(struct udevice *dev);
@@ -151,6 +158,24 @@ struct pinctrl_ops {
 	 */
 	 int (*get_pin_muxing)(struct udevice *dev, unsigned int selector,
 			       char *buf, int size);
+
+	/**
+	 * gpio_request_enable: requests and enables GPIO on a certain pin.
+	 *
+	 * @dev:	Pinctrl device to use
+	 * @selector:	Pin selector
+	 * return 0 if OK, -ve on error
+	 */
+	int (*gpio_request_enable)(struct udevice *dev, unsigned int selector);
+
+	/**
+	 * gpio_disable_free: free up GPIO muxing on a certain pin.
+	 *
+	 * @dev:	Pinctrl device to use
+	 * @selector:	Pin selector
+	 * return 0 if OK, -ve on error
+	 */
+	int (*gpio_disable_free)(struct udevice *dev, unsigned int selector);
 };
 
 #define pinctrl_get_ops(dev)	((struct pinctrl_ops *)(dev)->driver->ops)
@@ -407,4 +432,23 @@ int pinctrl_get_pins_count(struct udevice *dev);
  */
 int pinctrl_get_pin_name(struct udevice *dev, int selector, char *buf,
 			 int size);
+
+/**
+ * pinctrl_gpio_request() - request a single pin to be used as GPIO
+ *
+ * @dev: GPIO peripheral device
+ * @offset: the GPIO pin offset from the GPIO controller
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_gpio_request(struct udevice *dev, unsigned offset);
+
+/**
+ * pinctrl_gpio_free() - free a single pin used as GPIO
+ *
+ * @dev: GPIO peripheral device
+ * @offset: the GPIO pin offset from the GPIO controller
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_gpio_free(struct udevice *dev, unsigned offset);
+
 #endif /* __PINCTRL_H */