Hi Jacek, On Fri, Mar 27, 2015 at 02:49:43PM +0100, Jacek Anaszewski wrote: > This patch extends LED Flash class documention by > the description of interactions with v4l2-flash sub-device. > > Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> > Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > Cc: Bryan Wu <cooloney@xxxxxxxxx> > Cc: Richard Purdie <rpurdie@xxxxxxxxx> > --- > Documentation/leds/leds-class-flash.txt | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/Documentation/leds/leds-class-flash.txt b/Documentation/leds/leds-class-flash.txt > index 19bb673..8623413 100644 > --- a/Documentation/leds/leds-class-flash.txt > +++ b/Documentation/leds/leds-class-flash.txt > @@ -20,3 +20,16 @@ Following sysfs attributes are exposed for controlling flash LED devices: > - max_flash_timeout > - flash_strobe > - flash_fault > + > +A LED subsystem driver can be controlled also from the level of VideoForLinux2 > +subsystem. In order to enable this CONFIG_V4L2_FLASH_LED_CLASS symbol has to > +be defined in the kernel config. The driver must call the v4l2_flash_init > +function to get registered in the V4L2 subsystem. On remove the > +v4l2_flash_release function has to be called (see <media/v4l2-flash.h>). More information on using the interface functions would be nice, with a pointer to a driver that uses the interface. The simpler, the better I guess. > + > +After proper initialization a V4L2 Flash sub-device is created. The sub-device > +exposes a number of V4L2 controls, which allow for controlling a LED Flash class > +device with use of its internal kernel API. How about this: Once the V4L2 sub-device is registered by the driver which created the Media controller device, the sub-device node acts just as a node of a native V4L2 flash API device would. The calls are simply routed to the LED flash API. > +Opening the V4L2 Flash sub-device makes the LED subsystem sysfs interface > +unavailable. The interface is re-enabled after the V4L2 Flash sub-device > +is closed. -- Kind regards, Sakari Ailus e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
