gpio: Add a valid_mask getter

The valid_mask member of the struct gpio_chip is unconditionally written
by the GPIO core at driver registration. It shouldn't be directly
populated by drivers. This can be prevented by moving it from the struct
gpio_chip to struct gpio_device, which is internal to the GPIO core.

As a preparatory step, provide a getter function which can be used by
those drivers which need the valid_mask information.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/026f9d78502eca883bfe3faeb684e23d5d6c5e84.1741180097.git.mazziesaccount@gmail.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index b5f472beb3bd8ade0e57bcff30dbaae3a503ff9b..4c15a70d4d80030f7633d562e59ed67b439c6ba2 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -723,6 +723,22 @@ static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
        return 0;
 }
 
+/**
+ * gpiochip_query_valid_mask - return the GPIO validity information
+ * @gc:        gpio chip which validity information is queried
+ *
+ * Returns: bitmap representing valid GPIOs or NULL if all GPIOs are valid
+ *
+ * Some GPIO chips may support configurations where some of the pins aren't
+ * available. These chips can have valid_mask set to represent the valid
+ * GPIOs. This function can be used to retrieve this information.
+ */
+const unsigned long *gpiochip_query_valid_mask(const struct gpio_chip *gc)
+{
+       return gc->valid_mask;
+}
+EXPORT_SYMBOL_GPL(gpiochip_query_valid_mask);
+
 bool gpiochip_line_is_valid(const struct gpio_chip *gc,
                                unsigned int offset)
 {

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 83e0a7e86962124f5b4b5cd716a829fde6a125b3..e3b59fda62e03223541b4a02f8caae5485c02815 100644 (file)
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -720,6 +720,7 @@ bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset);
 /* Sleep persistence inquiry for drivers */
 bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset);
 bool gpiochip_line_is_valid(const struct gpio_chip *gc, unsigned int offset);
+const unsigned long *gpiochip_query_valid_mask(const struct gpio_chip *gc);
 
 /* get driver data */
 void *gpiochip_get_data(struct gpio_chip *gc);