Player LEDs are commonly found on game controllers from Nintendo and Sony
to indicate a player ID across a number of LEDs. For example, "Player 2"
might be indicated as "-x--" on a device with 4 LEDs where "x" means on.
This patch introduces a new LED_FUNCTION_PLAYER to properly indicate
player LEDs from the kernel. Until now there was no good standard, which
resulted in inconsistent behavior across xpad, hid-sony, hid-wiimote and
other drivers. Moving forward new drivers should use LED_FUNCTION_PLAYER.
Note: management of Player IDs is left to user space, though a kernel
driver may pick a default value.
Signed-off-by: Roderick Colenbrander <roderick.colenbrander@xxxxxxxx>
---
Documentation/leds/well-known-leds.txt | 14 ++++++++++++++
include/dt-bindings/leds/common.h | 3 +++
2 files changed, 17 insertions(+)
diff --git a/Documentation/leds/well-known-leds.txt b/Documentation/leds/well-known-leds.txt
index 4a8b9dc4bf52..2160382c86be 100644
--- a/Documentation/leds/well-known-leds.txt
+++ b/Documentation/leds/well-known-leds.txt
@@ -16,6 +16,20 @@ but then try the legacy ones, too.
Notice there's a list of functions in include/dt-bindings/leds/common.h .
+* Gamepads and joysticks
+
+Game controllers may feature LEDs to indicate a player number. This is commonly
+used on game consoles in which multiple controllers can be connected to a system.
+The "player LEDs" are then programmed with a pattern to indicate a particular
+player. For example, a game controller with 4 LEDs, may be programmed with "x---"
+to indicate player 1, "-x--" to indicate player 2 etcetera where "x" means on.
+Input drivers can utilize the LED class to expose the individual player LEDs
+of a game controller using the function "player".
+Note: tracking and management of Player IDs is the responsibility of user space,
+though drivers may pick a default value.
+
+Good: "input*:*:player-{1,2,3,4,5}
+
* Keyboards
Good: "input*:*:capslock"
diff --git a/include/dt-bindings/leds/common.h b/include/dt-bindings/leds/common.h
index 52b619d44ba2..94999c250e4d 100644
--- a/include/dt-bindings/leds/common.h
+++ b/include/dt-bindings/leds/common.h
@@ -60,6 +60,9 @@
#define LED_FUNCTION_MICMUTE "micmute"
#define LED_FUNCTION_MUTE "mute"
+/* Used for player LEDs as found on game controllers from e.g. Nintendo, Sony. */
+#define LED_FUNCTION_PLAYER "player"
+
/* Miscelleaus functions. Use functions above if you can. */
#define LED_FUNCTION_ACTIVITY "activity"
#define LED_FUNCTION_ALARM "alarm"
--
2.31.1
