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author | Sakari Ailus <sakari.ailus@iki.fi> | 2011-05-04 13:45:58 (GMT) |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-07-27 20:55:39 (GMT) |
commit | 7ba85fa4fdbbe800e92a937ca567120ef32fe49f (patch) | |
tree | 21e6e25380442d994ee3a1fb8d06b9da6a1abcd0 /Documentation | |
parent | 0b159acdd577dfd961ad14177c23e97d3ad33009 (diff) | |
download | linux-fsl-qoriq-7ba85fa4fdbbe800e92a937ca567120ef32fe49f.tar.xz |
[media] v4l: Add flash control documentation
Add documentation for V4L2 flash controls.
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/DocBook/media/v4l/compat.xml | 3 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/controls.xml | 283 | ||||
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml | 7 |
3 files changed, 293 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index d7c015e8..ce1004a 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2475,6 +2475,9 @@ ioctls.</para> <listitem> <para>&VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para> </listitem> + <listitem> + <para>Flash API. <xref linkend="flash-controls" /></para> + </listitem> </itemizedlist> </section> diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index a920ee8..9155127 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -2092,6 +2092,289 @@ manually or automatically if set to zero. Unit, range and step are driver-specif <para>For more details about RDS specification, refer to <xref linkend="en50067" /> document, from CENELEC.</para> </section> + + <section id="flash-controls"> + <title>Flash Control Reference</title> + + <note> + <title>Experimental</title> + + <para>This is an <link linkend="experimental">experimental</link> +interface and may change in the future.</para> + </note> + + <para> + The V4L2 flash controls are intended to provide generic access + to flash controller devices. Flash controller devices are + typically used in digital cameras. + </para> + + <para> + The interface can support both LED and xenon flash devices. As + of writing this, there is no xenon flash driver using this + interface. + </para> + + <section id="flash-controls-use-cases"> + <title>Supported use cases</title> + + <section> + <title>Unsynchronised LED flash (software strobe)</title> + + <para> + Unsynchronised LED flash is controlled directly by the + host as the sensor. The flash must be enabled by the host + before the exposure of the image starts and disabled once + it ends. The host is fully responsible for the timing of + the flash. + </para> + + <para>Example of such device: Nokia N900.</para> + </section> + + <section> + <title>Synchronised LED flash (hardware strobe)</title> + + <para> + The synchronised LED flash is pre-programmed by the host + (power and timeout) but controlled by the sensor through a + strobe signal from the sensor to the flash. + </para> + + <para> + The sensor controls the flash duration and timing. This + information typically must be made available to the + sensor. + </para> + + </section> + + <section> + <title>LED flash as torch</title> + + <para> + LED flash may be used as torch in conjunction with another + use case involving camera or individually. + </para> + + </section> + + </section> + + <table pgwide="1" frame="none" id="flash-control-id"> + <title>Flash Control IDs</title> + + <tgroup cols="4"> + <colspec colname="c1" colwidth="1*" /> + <colspec colname="c2" colwidth="6*" /> + <colspec colname="c3" colwidth="2*" /> + <colspec colname="c4" colwidth="6*" /> + <spanspec namest="c1" nameend="c2" spanname="id" /> + <spanspec namest="c2" nameend="c4" spanname="descr" /> + <thead> + <row> + <entry spanname="id" align="left">ID</entry> + <entry align="left">Type</entry> + </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry> + </row> + </thead> + <tbody valign="top"> + <row><entry></entry></row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry> + <entry>class</entry> + </row> + <row> + <entry spanname="descr">The FLASH class descriptor.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry> + <entry>menu</entry> + </row> + <row id="v4l2-flash-led-mode"> + <entry spanname="descr">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 presence of + some faults. See V4L2_CID_FLASH_FAULT.</entry> + </row> + <row> + <entrytbl spanname="descr" cols="2"> + <tbody valign="top"> + <row> + <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry> + <entry>Off.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry> + <entry>Flash mode.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry> + <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry> + </row> + </tbody> + </entrytbl> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry> + <entry>menu</entry> + </row> + <row id="v4l2-flash-strobe-source"><entry + spanname="descr">Defines the source of the flash LED + strobe.</entry> + </row> + <row> + <entrytbl spanname="descr" cols="2"> + <tbody valign="top"> + <row> + <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry> + <entry>The flash strobe is triggered by using + the V4L2_CID_FLASH_STROBE control.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry> + <entry>The flash strobe is triggered by an + external source. Typically this is a sensor, + which makes it possible to synchronises the + flash strobe start to exposure start.</entry> + </row> + </tbody> + </entrytbl> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry> + <entry>button</entry> + </row> + <row> + <entry spanname="descr">Strobe flash. Valid when + V4L2_CID_FLASH_LED_MODE is set to + V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE + is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this + control may not be possible in presence of some faults. + See V4L2_CID_FLASH_FAULT.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry> + <entry>button</entry> + </row> + <row><entry spanname="descr">Stop flash strobe immediately.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry> + <entry>boolean</entry> + </row> + <row> + <entry spanname="descr">Strobe status: whether the flash + is strobing at the moment or not. This is a read-only + control.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry> + <entry>integer</entry> + </row> + <row> + <entry spanname="descr">Hardware timeout for flash. The + flash strobe is stopped after this period of time has + passed from the start of the strobe.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry> + <entry>integer</entry> + </row> + <row> + <entry spanname="descr">Intensity of the flash strobe when + the flash LED is in flash mode + (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps + (mA) if possible.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry> + <entry>integer</entry> + </row> + <row> + <entry spanname="descr">Intensity of the flash LED in + torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be + milliamps (mA) if possible. Setting this control may not + be possible in presence of some faults. See + V4L2_CID_FLASH_FAULT.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry> + <entry>integer</entry> + </row> + <row> + <entry spanname="descr">Intensity of the indicator LED. + The indicator LED may be fully independent of the flash + LED. The unit should be microamps (uA) if possible.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry> + <entry>bitmask</entry> + </row> + <row> + <entry spanname="descr">Faults related to the flash. The + faults tell about specific problems in the flash chip + itself or the LEDs attached to it. Faults may prevent + further use of some of the flash controls. In particular, + V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE + if the fault affects the flash LED. Exactly which faults + have such an effect is chip dependent. Reading the faults + resets the control and returns the chip to a usable state + if possible.</entry> + </row> + <row> + <entrytbl spanname="descr" cols="2"> + <tbody valign="top"> + <row> + <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry> + <entry>Flash controller voltage to the flash LED + has exceeded the limit specific to the flash + controller.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry> + <entry>The flash strobe was still on when + the timeout set by the user --- + V4L2_CID_FLASH_TIMEOUT control --- has expired. + Not all flash controllers may set this in all + such conditions.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry> + <entry>The flash controller has overheated.</entry> + </row> + <row> + <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry> + <entry>The short circuit protection of the flash + controller has been triggered.</entry> + </row> + </tbody> + </entrytbl> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry> + <entry>boolean</entry> + </row> + <row><entry spanname="descr">Enable or disable charging of the xenon + flash capacitor.</entry> + </row> + <row> + <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry> + <entry>boolean</entry> + </row> + <row> + <entry spanname="descr">Is the flash ready to strobe? + Xenon flashes require their capacitors 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.</entry> + </row> + <row><entry></entry></row> + </tbody> + </tgroup> + </table> + + </section> </section> <!-- diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml index 5e73517..5122ce8 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml @@ -250,6 +250,13 @@ These controls are described in <xref These controls are described in <xref linkend="fm-tx-controls" />.</entry> </row> + <row> + <entry><constant>V4L2_CTRL_CLASS_FLASH</constant></entry> + <entry>0x9c0000</entry> + <entry>The class containing flash device controls. +These controls are described in <xref + linkend="flash-controls" />.</entry> + </row> </tbody> </tgroup> </table> |