gpiolib: add gpiochip_get_desc() driver function
Some drivers dealing with a gpio_chip might need to act on its
descriptors directly; one example is pinctrl drivers that need to lock a
GPIO for being used as IRQ using gpiod_lock_as_irq().
This patch exports a gpiochip_get_desc() function that returns the
GPIO descriptor at the requested index. It also sweeps the
gpio_to_chip() function out of the consumer interface since any holder
of a gpio_chip reference can manipulate its GPIOs way beyond what a
consumer should be allowed to do.
As a result, gpio_chip is not visible anymore to simple GPIO consumers.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index a3e181e..9fe2836 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -10,6 +10,8 @@
struct device_node;
struct seq_file;
+#ifdef CONFIG_GPIOLIB
+
/**
* struct gpio_chip - abstract a GPIO controller
* @label: for diagnostics
@@ -129,6 +131,11 @@
int gpiod_lock_as_irq(struct gpio_desc *desc);
void gpiod_unlock_as_irq(struct gpio_desc *desc);
+struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc);
+
+struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
+ u16 hwnum);
+
enum gpio_lookup_flags {
GPIO_ACTIVE_HIGH = (0 << 0),
GPIO_ACTIVE_LOW = (1 << 0),
@@ -183,4 +190,15 @@
void gpiod_add_lookup_table(struct gpiod_lookup_table *table);
+#else /* CONFIG_GPIOLIB */
+
+static inline struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
+{
+ /* GPIO can never have been requested */
+ WARN_ON(1);
+ return ERR_PTR(-ENODEV);
+}
+
+#endif /* CONFIG_GPIOLIB */
+
#endif