Add generic support for composing LED class device name basing on
fwnode_handle data. The function composes device name according to
either a new <color:function> pattern or the legacy
<devicename:color:function> pattern. The decision on using the
particular pattern is made basing on whether fwnode contains new
"function" and "color" properties, or the legacy "label" proeprty.
Backward compatibility with in-driver hard-coded LED class device
names is assured thanks to the default_label and led_hw_name properties
of newly introduced struct led_init_data.
In case none of the aforementioned properties was found, then, for OF
nodes, the node name is adopted for LED class device name.
At the occassion of amending the Documentation/leds/leds-class.txt
unify spelling: colour -> color.
Alongside these changes added is a new tool - tools/leds/get_led_device_info.sh.
The tool allows retrieving details of a LED class device's parent device,
which proves that getting rid of a devicename section from LED name pattern
is justified since this information is already available in sysfs.
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
Cc: Baolin Wang <baolin.wang@xxxxxxxxxx>
Cc: Pavel Machek <pavel@xxxxxx>
Cc: Dan Murphy <dmurphy@xxxxxx>
Cc: Daniel Mack <daniel@xxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Oleh Kravchenko <oleg@xxxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Cc: Simon Shields <simon@xxxxxxxxxxxxx>
---
Documentation/leds/leds-class.txt | 27 +++++++++--
drivers/leds/led-class.c | 29 ++++++++++--
drivers/leds/led-core.c | 96 +++++++++++++++++++++++++++++++++++++++
include/linux/leds.h | 43 ++++++++++++++++++
tools/leds/get_led_device_info.sh | 81 +++++++++++++++++++++++++++++++++
5 files changed, 270 insertions(+), 6 deletions(-)
create mode 100755 tools/leds/get_led_device_info.sh
diff --git a/Documentation/leds/leds-class.txt b/Documentation/leds/leds-class.txt
index 8b39cc6b03ee..11e19c3c2e4d 100644
--- a/Documentation/leds/leds-class.txt
+++ b/Documentation/leds/leds-class.txt
@@ -43,14 +43,35 @@ LED Device Naming
Is currently of the form:
-"devicename:colour:function"
-
-There have been calls for LED properties such as colour to be exported as
+"color:function"
+
+There might be still LED class drivers around using "devicename:color:function"
+naming pattern, but the "devicename" section is now deprecated since it used
+to convey information that was already available in the sysfs, like product
+name. There is a tool (tools/leds/get_led_device_info.sh) available for
+retrieving that information per a LED class device.
+
+Associations with other devices, like network ones, should be defined
+via LED trigger mechanism. This approach is applied by some of wireless
+network drivers that create triggers dynamically and incorporate phy
+name into the trigger name. On the other hand input subsystem offers LED - input
+bridge (drivers/input/input-leds.c) for exposing keyboard LEDs as LED class
+devices. The get_led_device_info.sh script has support for retrieving related
+input device node name. Should it support discovery of associations between
+LEDs and other subsystems, please don't hesitate to submit a relevant patch.
+
+There have been calls for LED properties such as color to be exported as
individual led class attributes. As a solution which doesn't incur as much
overhead, I suggest these become part of the device name. The naming scheme
above leaves scope for further attributes should they be needed. If sections
of the name don't apply, just leave that section blank.
+Please also keep in mind that LED subsystem has a protection against LED name
+conflict. It adds numerical suffix (e.g. "_1", "_2", "_3" etc.) to the requested
+LED class device name in case it is already in use. In order to prevent LED core
+from assigning these suffixes in an arbitrary order the led-enumerator fwnode
+property can be used for differentiation of LEDs that share common function
+and/or color. In this case enumerators will be prepended with "-" character.
Brightness setting API
======================
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 2f09156b0c63..bfd46a9bba63 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -26,6 +26,18 @@
static struct class *leds_class;
+const char *led_colors[LED_COLOR_ID_COUNT] = {
+ [LED_COLOR_ID_WHITE] = "white",
+ [LED_COLOR_ID_RED] = "red",
+ [LED_COLOR_ID_GREEN] = "green",
+ [LED_COLOR_ID_BLUE] = "blue",
+ [LED_COLOR_ID_AMBER] = "amber",
+ [LED_COLOR_ID_VIOLET] = "violet",
+ [LED_COLOR_ID_YELLOW] = "yellow",
+ [LED_COLOR_ID_IR] = "ir",
+};
+EXPORT_SYMBOL_GPL(led_colors);
+
