[RFC v2 3/5] pinctrl: add pinctrl_gpio_get_config()

[AKASHI Takahiro]

This is a counterpart of pinctrl_gpio_set_config() which will be used,
at least initially, to implement gpio_get interface in pin controller
based generic gpio driver.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
RFC (Oct 2, 2023)
---
 drivers/pinctrl/core.c           | 19 +++++++++++++++++++
 include/linux/pinctrl/consumer.h |  8 ++++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index e9dc9638120a..2f9c2efdfe0e 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -926,6 +926,25 @@ int pinctrl_gpio_set_config(unsigned gpio, unsigned long config)
 }
 EXPORT_SYMBOL_GPL(pinctrl_gpio_set_config);
 
+int pinctrl_gpio_get_config(unsigned int gpio, unsigned long *config)
+{
+	struct pinctrl_gpio_range *range;
+	struct pinctrl_dev *pctldev;
+	int ret, pin;
+
+	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
+	if (ret)
+		return ret;
+
+	mutex_lock(&pctldev->mutex);
+	pin = gpio_to_pin(range, gpio);
+	ret = pin_config_get_for_pin(pctldev, pin, config);
+	mutex_unlock(&pctldev->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pinctrl_gpio_get_config);
+
 static struct pinctrl_state *find_state(struct pinctrl *p,
 					const char *name)
 {
diff --git a/include/linux/pinctrl/consumer.h b/include/linux/pinctrl/consumer.h
index 4729d54e8995..852fac97a79b 100644
--- a/include/linux/pinctrl/consumer.h
+++ b/include/linux/pinctrl/consumer.h
@@ -31,6 +31,8 @@ extern void pinctrl_gpio_free(unsigned gpio);
 extern int pinctrl_gpio_direction_input(unsigned gpio);
 extern int pinctrl_gpio_direction_output(unsigned gpio);
 extern int pinctrl_gpio_set_config(unsigned gpio, unsigned long config);
+extern int pinctrl_gpio_get_config(unsigned int gpio,
+				   unsigned long *config);
 
 extern struct pinctrl * __must_check pinctrl_get(struct device *dev);
 extern void pinctrl_put(struct pinctrl *p);
@@ -92,6 +94,12 @@ static inline int pinctrl_gpio_set_config(unsigned gpio, unsigned long config)
 	return 0;
 }
 
+static inline int pinctrl_gpio_get_config(unsigned int gpio,
+					  unsigned long *config)
+{
+	return 0;
+}
+
 static inline struct pinctrl * __must_check pinctrl_get(struct device *dev)
 {
 	return NULL;
-- 
2.34.1