gpio: Documentation update

[sfrench/cifs-2.6.git] / Documentation / gpio / board.txt

diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt
index a0f61898d493b720fbc014554b628f5b6e25a93f..b1d106167baaa2d4f8cbcb2f1ae504a31ebf8885 100644 (file)
--- a/Documentation/gpio/board.txt
+++ b/Documentation/gpio/board.txt
@@ -2,6 +2,7 @@ GPIO Mappings
 =============
 
 This document explains how GPIOs can be assigned to given devices and functions.
+
 Note that it only applies to the new descriptor-based interface. For a
 description of the deprecated integer-based GPIO interface please refer to
 gpio-legacy.txt (actually, there is no real mapping possible with the old
@@ -49,7 +50,7 @@ This property will make GPIOs 15, 16 and 17 available to the driver under the
 
        power = gpiod_get(dev, "power", GPIOD_OUT_HIGH);
 
-The led GPIOs will be active-high, while the power GPIO will be active-low (i.e.
+The led GPIOs will be active high, while the power GPIO will be active low (i.e.
 gpiod_is_active_low(power) will be true).
 
 The second parameter of the gpiod_get() functions, the con_id string, has to be
@@ -122,9 +123,14 @@ where
        can be NULL, in which case it will match any function.
   - idx is the index of the GPIO within the function.
   - flags is defined to specify the following properties:
-       * GPIOF_ACTIVE_LOW      - to configure the GPIO as active-low
-       * GPIOF_OPEN_DRAIN      - GPIO pin is open drain type.
-       * GPIOF_OPEN_SOURCE     - GPIO pin is open source type.
+       * GPIO_ACTIVE_HIGH      - GPIO line is active high
+       * GPIO_ACTIVE_LOW       - GPIO line is active low
+       * GPIO_OPEN_DRAIN       - GPIO line ise set up as open drain
+       * GPIO_OPEN_SOURCE      - GPIO line is set up as open source
+       * GPIO_PERSISTENT       - GPIO line is persistent during
+                                 suspend/resume and maintains its value
+       * GPIO_TRANSITORY       - GPIO line is transitory and may loose its
+                                 electrical state during suspend/resume
 
 In the future, these flags might be extended to support more properties.