On Wed, Nov 12, 2014 at 8:09 AM, Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> wrote: > The documentation being added contains overall description of the > LED Flash Class and the related sysfs attributes. > > Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > Cc: Bryan Wu <cooloney@xxxxxxxxx> > Cc: Richard Purdie <rpurdie@xxxxxxxxx> > --- > Documentation/leds/leds-class-flash.txt | 39 +++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > create mode 100644 Documentation/leds/leds-class-flash.txt > > diff --git a/Documentation/leds/leds-class-flash.txt b/Documentation/leds/leds-class-flash.txt > new file mode 100644 > index 0000000..0164329 > --- /dev/null > +++ b/Documentation/leds/leds-class-flash.txt > @@ -0,0 +1,39 @@ > + > +Flash LED handling under Linux > +============================== > + > +Some LED devices support two modes - torch and flash. In order to enable I think I asked this question before, Torch, Flash and Indicator. As you answered torch is implemented by sync led brightness set operation in our LEDS_CLASS and Flash is implemented in this LEDS_CLASS_FLASH. I suggest put this information in document or code comments. Then people know how to use torch and flash. For indicator I still don't know why we need this since indicator is like blinking and it should be support by LEDS_CLASS right? Flash is for some camera capture, right? > +support for flash LEDs CONFIG_LEDS_CLASS_FLASH symbol must be defined > +in the kernel config. A flash LED driver must register in the LED subsystem > +with led_classdev_flash_register to gain flash capabilities. > + > +Following sysfs attributes are exposed for controlling flash led devices: > + > + - flash_brightness - flash LED brightness in microamperes (RW) > + - max_flash_brightness - maximum available flash LED brightness (RO) > + - indicator_brightness - privacy LED brightness in microamperes (RW) > + - max_indicator_brightness - maximum privacy LED brightness in > + microamperes (RO) What's the privacy mean here? > + - flash_timeout - flash strobe duration in microseconds (RW) > + - max_flash_timeout - maximum available flash strobe duration (RO) > + - flash_strobe - flash strobe state (RW) > + - flash_fault - bitmask of flash faults that may have occurred, > + possible flags are: > + * 0x01 - flash controller voltage to the flash LED has exceeded > + the limit specific to the flash controller > + * 0x02 - 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 > + * 0x04 - the flash controller has overheated > + * 0x08 - the short circuit protection of the flash controller > + has been triggered > + * 0x10 - current in the LED power supply has exceeded the limit > + specific to the flash controller > + * 0x40 - flash controller voltage to the flash LED has been > + below the minimum limit specific to the flash > + * 0x80 - 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 > + * 0x100 - the temperature of the LED has exceeded its allowed > + upper limit Are these error code the same for all the LED controller? Or just for some specific chip? > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
