From: Richard Leitner Date: Tue, 9 Dec 2025 22:44:38 +0000 (+0100) Subject: Documentation: uAPI: media: add V4L2_CID_FLASH_{DURATION,STROBE_OE} X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa0e06f2fe00fa9e283a15d85e7542a4b72a14a7;p=thirdparty%2Fkernel%2Flinux.git Documentation: uAPI: media: add V4L2_CID_FLASH_{DURATION,STROBE_OE} Add the new strobe duration and hardware strobe output enable to v4l uAPI documentation. Additionally add labels for cross-referencing v4l controls. Signed-off-by: Richard Leitner Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil --- diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst index bd024ab461a40..b7f45fc0a797f 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-flash.rst @@ -58,6 +58,8 @@ Flash Control IDs ``V4L2_CID_FLASH_CLASS (class)`` The FLASH class descriptor. +.. _v4l2-cid-flash-led-mode: + ``V4L2_CID_FLASH_LED_MODE (menu)`` Defines the mode of the flash LED, the high-power white LED attached to the flash controller. Setting this control may not be possible in @@ -81,6 +83,8 @@ Flash Control IDs +.. _v4l2-cid-flash-strobe-source: + ``V4L2_CID_FLASH_STROBE_SOURCE (menu)`` Defines the source of the flash LED strobe. @@ -97,6 +101,12 @@ Flash Control IDs - The flash strobe is triggered by an external source. Typically this is a sensor, which makes it possible to synchronise the flash strobe start to exposure start. + This method of controlling flash LED strobe has two additional + prerequisites: the strobe source's :ref:`strobe output + ` must be enabled (if available) + and the flash controller's :ref:`flash LED mode + ` must be set to + ``V4L2_FLASH_LED_MODE_FLASH``. @@ -187,3 +197,35 @@ Flash Control IDs charged before strobing. LED flashes often require a cooldown period after strobe during which another strobe will not be possible. This is a read-only control. + +.. _v4l2-cid-flash-duration: + +``V4L2_CID_FLASH_DURATION (integer)`` + Duration of the flash strobe pulse generated by the strobe source, when + using external strobe. This control shall be implemented by the device + generating the hardware flash strobe signal, typically a camera sensor, + connected to a flash controller. + + The flash controllers :ref:`strobe source ` + must be configured to ``V4L2_FLASH_STROBE_SOURCE_EXTERNAL`` for this + mode of operation. For more details please also take a look at the + documentation there. + + The unit should be microseconds (µs) if possible. + +.. _v4l2-cid-flash-strobe-oe: + +``V4L2_CID_FLASH_STROBE_OE (boolean)`` + Enables the output of a hardware strobe signal from the strobe source, + when using external strobe. This control shall be implemented by the device + generating the hardware flash strobe signal, typically a camera sensor, + connected to a flash controller. + + Provided the signal generating device driver supports it, the length of the + strobe signal can be configured by adjusting its + :ref:`flash duration `. + + The flash controllers :ref:`strobe source ` + must be configured to ``V4L2_FLASH_STROBE_SOURCE_EXTERNAL`` for this + mode of operation. For more details please also take a look at the + documentation there.