diff options
Diffstat (limited to 'Documentation/gpio/driver.txt')
| -rw-r--r-- | Documentation/gpio/driver.txt | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt index 18790c237977..90d0f6aba7a6 100644 --- a/Documentation/gpio/driver.txt +++ b/Documentation/gpio/driver.txt @@ -124,7 +124,8 @@ symbol: * gpiochip_set_chained_irqchip(): sets up a chained irq handler for a gpio_chip from a parent IRQ and passes the struct gpio_chip* as handler data. (Notice handler data, since the irqchip data is likely used by the - parent irqchip!) This is for the chained type of chip. + parent irqchip!) This is for the chained type of chip. This is also used + to set up a nested irqchip if NULL is passed as handler. To use the helpers please keep the following in mind: @@ -157,12 +158,12 @@ Locking IRQ usage Input GPIOs can be used as IRQ signals. When this happens, a driver is requested to mark the GPIO as being used as an IRQ: - int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset) + int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) This will prevent the use of non-irq related GPIO APIs until the GPIO IRQ lock is released: - void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) + void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) When implementing an irqchip inside a GPIO driver, these two functions should typically be called in the .startup() and .shutdown() callbacks from the @@ -178,7 +179,8 @@ does not help since it pins the module to the kernel forever (it calls try_module_get()). A GPIO driver can use the following functions instead to request and free descriptors without being pinned to the kernel forever. - int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label) + struct gpio_desc *gpiochip_request_own_desc(struct gpio_desc *desc, + const char *label) void gpiochip_free_own_desc(struct gpio_desc *desc) |