leds: flash: document sysfs interface

Add a documentation of LED Flash class specific sysfs attributes.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-led-flash b/Documentation/ABI/testing/sysfs-class-led-flash
new file mode 100644
index 000000000000..220a0270b47b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-flash
@@ -0,0 +1,80 @@
+What:           /sys/class/leds/<led>/flash_brightness
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read/write
+                Set the brightness of this LED in the flash strobe mode, in
+                microamperes. The file is created only for the flash LED devices
+                that support setting flash brightness.
+
+                The value is between 0 and
+                /sys/class/leds/<led>/max_flash_brightness.
+
+What:           /sys/class/leds/<led>/max_flash_brightness
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read only
+                Maximum brightness level for this LED in the flash strobe mode,
+                in microamperes.
+
+What:           /sys/class/leds/<led>/flash_timeout
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read/write
+                Hardware timeout for flash, in microseconds. The flash strobe
+                is stopped after this period of time has passed from the start
+                of the strobe. The file is created only for the flash LED
+                devices that support setting flash timeout.
+
+What:           /sys/class/leds/<led>/max_flash_timeout
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read only
+                Maximum flash timeout for this LED, in microseconds.
+
+What:           /sys/class/leds/<led>/flash_strobe
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read/write
+                Flash strobe state. When written with 1 it triggers flash strobe
+                and when written with 0 it turns the flash off.
+
+                On read 1 means that flash is currently strobing and 0 means
+                that flash is off.
+
+What:           /sys/class/leds/<led>/flash_fault
+Date:           March 2015
+KernelVersion:  4.0
+Contact:        Jacek Anaszewski <j.anaszewski@samsung.com>
+Description:    read only
+                Space separated list of flash faults that may have occurred.
+                Flash faults are re-read after strobing the flash. Possible
+                flash faults:
+
+                * led-over-voltage - flash controller voltage to the flash LED
+                        has exceeded the limit specific to the flash controller
+                * flash-timeout-exceeded - the flash strobe was still on when
+                        the timeout set by the user has expired; not all flash
+                        controllers may set this in all such conditions
+                * controller-over-temperature - the flash controller has
+                        overheated
+                * controller-short-circuit - the short circuit protection
+                        of the flash controller has been triggered
+                * led-power-supply-over-current - current in the LED power
+                        supply has exceeded the limit specific to the flash
+                        controller
+                * indicator-led-fault - the flash controller has detected
+                        a short or open circuit condition on the indicator LED
+                * led-under-voltage - flash controller voltage to the flash
+                        LED has been below the minimum limit specific to
+                        the flash
+                * controller-under-voltage - the input voltage of the flash
+                        controller is below the limit under which strobing the
+                        flash at full current will not be possible;
+                        the condition persists until this flag is no longer set
+                * led-over-temperature - the temperature of the LED has exceeded
+                        its allowed upper limit