From 1248c7cb66d734b60efed41be7c7b86909812c0e Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 10 Aug 2012 05:45:51 -0300 Subject: [PATCH] [media] V4L2 spec: document the new DV controls and ioctls Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/media/v4l/biblio.xml | 40 +++++ Documentation/DocBook/media/v4l/controls.xml | 161 +++++++++++++++++++ Documentation/DocBook/media/v4l/v4l2.xml | 1 + 3 files changed, 202 insertions(+) diff --git a/Documentation/DocBook/media/v4l/biblio.xml b/Documentation/DocBook/media/v4l/biblio.xml index 18b6fc9ff58b..d2eb79e41a01 100644 --- a/Documentation/DocBook/media/v4l/biblio.xml +++ b/Documentation/DocBook/media/v4l/biblio.xml @@ -226,4 +226,44 @@ in the frequency range from 87,5 to 108,0 MHz VESA and Industry Standards and Guidelines for Computer Display Monitor Timing (DMT) + + EDID + + Video Electronics Standards Association +(http://www.vesa.org) + + VESA Enhanced Extended Display Identification Data Standard + Release A, Revision 2 + + + + HDCP + + Digital Content Protection LLC +(http://www.digital-cp.com) + + High-bandwidth Digital Content Protection System + Revision 1.3 + + + + HDMI + + HDMI Licensing LLC +(http://www.hdmi.org) + + High-Definition Multimedia Interface + Specification Version 1.4a + + + + DP + + Video Electronics Standards Association +(http://www.vesa.org) + + VESA DisplayPort Standard + Version 1, Revision 2 + + diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index 93b9c6872e53..272a5f718509 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -4273,4 +4273,165 @@ interface and may change in the future. + +
+ Digital Video Control Reference + + + Experimental + + This is an experimental interface and may + change in the future. + + + + The Digital Video control class is intended to control receivers + and transmitters for VGA, + DVI + (Digital Visual Interface), HDMI () and DisplayPort (). + These controls are generally expected to be private to the receiver or transmitter + subdevice that implements them, so they are only exposed on the + /dev/v4l-subdev* device node. + + + Note that these devices can have multiple input or output pads which are + hooked up to e.g. HDMI connectors. Even though the subdevice will receive or + transmit video from/to only one of those pads, the other pads can still be + active when it comes to EDID (Extended Display Identification Data, + ) and HDCP (High-bandwidth Digital Content + Protection System, ) processing, allowing the device + to do the fairly slow EDID/HDCP handling in advance. This allows for quick + switching between connectors. + + These pads appear in several of the controls in this section as + bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1, + etc. The maximum value of the control is the set of valid pads. + + + Digital Video Control IDs + + + + + + + + + + + ID + Type + Description + + + + + + V4L2_CID_DV_CLASS + class + + + The Digital Video class descriptor. + + + V4L2_CID_DV_TX_HOTPLUG + bitmask + + + Many connectors have a hotplug pin which is high + if EDID information is available from the source. This control shows the + state of the hotplug pin as seen by the transmitter. + Each bit corresponds to an output pad on the transmitter. If an output pad + does not have an associated hotplug pin, then the bit for that pad will be 0. + This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors. + + + + V4L2_CID_DV_TX_RXSENSE + bitmask + + + Rx Sense is the detection of pull-ups on the TMDS + clock lines. This normally means that the sink has left/entered standby (i.e. + the transmitter can sense that the receiver is ready to receive video). + Each bit corresponds to an output pad on the transmitter. If an output pad + does not have an associated Rx Sense, then the bit for that pad will be 0. + This read-only control is applicable to DVI-D and HDMI devices. + + + + V4L2_CID_DV_TX_EDID_PRESENT + bitmask + + + When the transmitter sees the hotplug signal from the + receiver it will attempt to read the EDID. If set, then the transmitter has read + at least the first block (= 128 bytes). + Each bit corresponds to an output pad on the transmitter. If an output pad + does not support EDIDs, then the bit for that pad will be 0. + This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors. + + + + V4L2_CID_DV_TX_MODE + enum v4l2_dv_tx_mode + + + HDMI transmitters can transmit in DVI-D mode (just video) + or in HDMI mode (video + audio + auxiliary data). This control selects which mode + to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI. + This control is applicable to HDMI connectors. + + + + V4L2_CID_DV_TX_RGB_RANGE + enum v4l2_dv_rgb_range + + + Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO + follows the RGB quantization range specified in the standard for the video interface + (ie. for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard + to be compatible with sinks that have not implemented the standard correctly + (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be + used whereas limited range sets the range to (16 << (N-8)) - (235 << (N-8)) + where N is the number of bits per component. + This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors. + + + + V4L2_CID_DV_RX_POWER_PRESENT + bitmask + + + Detects whether the receiver receives power from the source + (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom + which contains EDID information, such that the source can read the EDID even if + the sink is in standby/power off. + Each bit corresponds to an input pad on the transmitter. If an input pad + cannot detect whether power is present, then the bit for that pad will be 0. + This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors. + + + + V4L2_CID_DV_RX_RGB_RANGE + enum v4l2_dv_rgb_range + + + Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO + follows the RGB quantization range specified in the standard for the video interface + (ie. for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard + to be compatible with sources that have not implemented the standard correctly + (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be + used whereas limited range sets the range to (16 << (N-8)) - (235 << (N-8)) + where N is the number of bits per component. + This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors. + + + + + +
+ +
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index 0292ed106887..10ccde9d16d0 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -581,6 +581,7 @@ and discussions on the V4L mailing list. &sub-subdev-enum-frame-size; &sub-subdev-enum-mbus-code; &sub-subdev-g-crop; + &sub-subdev-g-edid; &sub-subdev-g-fmt; &sub-subdev-g-frame-interval; &sub-subdev-g-selection; -- 2.30.2