[PATCHv2 5/6] gpio/driver.rst: document gpiochip_disable/enable_irq()

[Hans Verkuil <hverkuil@xxxxxxxxx>]

From: Hans Verkuil <hans.verkuil@xxxxxxxxx>

Document these new functions.

Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
---
 Documentation/driver-api/gpio/driver.rst | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst
index cbe0242842d1..a6c14ff0c54f 100644
--- a/Documentation/driver-api/gpio/driver.rst
+++ b/Documentation/driver-api/gpio/driver.rst
@@ -374,7 +374,28 @@ When implementing an irqchip inside a GPIO driver, these two functions should
 typically be called in the .startup() and .shutdown() callbacks from the
 irqchip.
 
-When using the gpiolib irqchip helpers, these callback are automatically
+When using the gpiolib irqchip helpers, these callbacks are automatically
+assigned.
+
+
+Disabling and enabling IRQs
+---------------------------
+When a GPIO is used as an IRQ signal, then gpiolib also needs to know if
+the IRQ is enabled or disabled. In order to inform gpiolib about this,
+a driver should call::
+
+	void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset)
+
+This allows drivers to drive the GPIO as an output while the IRQ is
+disabled. When the IRQ is enabled again, a driver should call::
+
+	void gpiochip_enable_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 .irq_disable() and .irq_enable() callbacks from the
+irqchip.
+
+When using the gpiolib irqchip helpers, these callbacks are automatically
 assigned.
 
 Real-Time compliance for GPIO IRQ chips
-- 
2.18.0