X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=blobdiff_plain;f=Documentation%2Fgpio%2Fdriver.txt;h=368d5a294d8937d7c0ea0fa157525667f8549c7f;hp=6cb35a78eff4c5c50073a2cdb4dac603a3a16b79;hb=fed41f7d039bad02f94cad9059e4b14cd81d13f2;hpb=643d09f4618196d05ecf9b6987c890280ffac9d8

diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 6cb35a78eff4..368d5a294d89 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -262,6 +262,12 @@ symbol:
   to the container using container_of().
   (See Documentation/driver-model/design-patterns.txt)
 
+  If there is a need to exclude certain GPIOs from the IRQ domain, one can
+  set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
+  called. This allocates .irq_valid_mask with as many bits set as there are
+  GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
+  mask. The mask must be filled in before gpiochip_irqchip_add() is called.
+
 * 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