gpio: better lookup method for platform GPIOs

[~andy/linux] / Documentation / gpio / board.txt

diff --git a/Documentation/gpio/board.txt b/Documentation/gpio/board.txt
index 0d03506f2cc562308010b3ee9b3d4d5db2d7136f..ba169faad5c63b1d969262b61e8b59aad72881c2 100644 (file)
--- a/Documentation/gpio/board.txt
+++ b/Documentation/gpio/board.txt
@@ -72,10 +72,11 @@ where
 
   - chip_label is the label of the gpiod_chip instance providing the GPIO
   - chip_hwnum is the hardware number of the GPIO within the chip
-  - dev_id is the identifier of the device that will make use of this GPIO. If
-       NULL, the GPIO will be available to all devices.
+  - dev_id is the identifier of the device that will make use of this GPIO. It
+       can be NULL, in which case it will be matched for calls to gpiod_get()
+       with a NULL device.
   - con_id is the name of the GPIO function from the device point of view. It
-       can be NULL.
+       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
@@ -86,18 +87,23 @@ In the future, these flags might be extended to support more properties.
 
 Note that GPIO_LOOKUP() is just a shortcut to GPIO_LOOKUP_IDX() where idx = 0.
 
-A lookup table can then be defined as follows:
+A lookup table can then be defined as follows, with an empty entry defining its
+end:
 
-       struct gpiod_lookup gpios_table[] = {
-       GPIO_LOOKUP_IDX("gpio.0", 15, "foo.0", "led", 0, GPIO_ACTIVE_HIGH),
-       GPIO_LOOKUP_IDX("gpio.0", 16, "foo.0", "led", 1, GPIO_ACTIVE_HIGH),
-       GPIO_LOOKUP_IDX("gpio.0", 17, "foo.0", "led", 2, GPIO_ACTIVE_HIGH),
-       GPIO_LOOKUP("gpio.0", 1, "foo.0", "power", GPIO_ACTIVE_LOW),
-       };
+struct gpiod_lookup_table gpios_table = {
+       .dev_id = "foo.0",
+       .table = {
+               GPIO_LOOKUP_IDX("gpio.0", 15, "led", 0, GPIO_ACTIVE_HIGH),
+               GPIO_LOOKUP_IDX("gpio.0", 16, "led", 1, GPIO_ACTIVE_HIGH),
+               GPIO_LOOKUP_IDX("gpio.0", 17, "led", 2, GPIO_ACTIVE_HIGH),
+               GPIO_LOOKUP("gpio.0", 1, "power", GPIO_ACTIVE_LOW),
+               { },
+       },
+};
 
 And the table can be added by the board code as follows:
 
-       gpiod_add_table(gpios_table, ARRAY_SIZE(gpios_table));
+       gpiod_add_lookup_table(&gpios_table);
 
 The driver controlling "foo.0" will then be able to obtain its GPIOs as follows: