Re: Preliminary proposal, new APIs for HDMI and DVI control in v4l2
Hi Soby On 05/27/2012 07:30 PM, Soby Mathew wrote: Martin Bugge (marbuggemarbuggeat cisco.com writes: This is a preliminary proposal for an extension to the v4l2 api. To be discussed at the V4L2 'brainstorming' meeting in Warsaw, March 2011 Purpose: Provide basic controls for HDMI and DVI devices. reposting the query since the earlier post did not appear in mailing list. Hi Martin, We are also in requirement of these controls as described by you. I did a search in the archives but could not find a suitable conclusion to the RFC. I could find that the dv_timings structure has been modified as a result of further discussions. But for many items like S_EDID, DV_CABLE_DETECT, Info frames etc , I could not find the logical conclusion to this RFC. Could please let me know the further updates on these requirements? It has been on hold for a very long time, but just last week Hans Verkuil posted a RFC which is a follow up on this subject. http://www.spinics.net/lists/linux-media/msg47671.html So that thread has taken over. Thanks in Advance Best Regards Soby Mathew Best regards Martin Bugge -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Preliminary proposal, new APIs for HDMI and DVI control in v4l2
On Wed 30 May 2012 13:13:27 Martin Bugge (marbugge) wrote: Hi Soby On 05/27/2012 07:30 PM, Soby Mathew wrote: Martin Bugge (marbuggemarbuggeat cisco.com writes: This is a preliminary proposal for an extension to the v4l2 api. To be discussed at the V4L2 'brainstorming' meeting in Warsaw, March 2011 Purpose: Provide basic controls for HDMI and DVI devices. reposting the query since the earlier post did not appear in mailing list. Hi Martin, We are also in requirement of these controls as described by you. I did a search in the archives but could not find a suitable conclusion to the RFC. I could find that the dv_timings structure has been modified as a result of further discussions. But for many items like S_EDID, DV_CABLE_DETECT, Info frames etc , I could not find the logical conclusion to this RFC. Could please let me know the further updates on these requirements? It has been on hold for a very long time, but just last week Hans Verkuil posted a RFC which is a follow up on this subject. http://www.spinics.net/lists/linux-media/msg47671.html So that thread has taken over. And expect to see a small patch series to be posted in the next few days containing a slightly changed version of the proposal, including DocBook documentation. Please review those patches when they are posted and let us know if you are OK with it or if you have additional requirements. Regards, Hans -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Preliminary proposal, new APIs for HDMI and DVI control in v4l2
Martin Bugge (marbugge marbugge at cisco.com writes: This is a preliminary proposal for an extension to the v4l2 api. To be discussed at the V4L2 'brainstorming' meeting in Warsaw, March 2011 Purpose: Provide basic controls for HDMI and DVI devices. reposting the query since the earlier post did not appear in mailing list. Hi Martin, We are also in requirement of these controls as described by you. I did a search in the archives but could not find a suitable conclusion to the RFC. I could find that the dv_timings structure has been modified as a result of further discussions. But for many items like S_EDID, DV_CABLE_DETECT, Info frames etc , I could not find the logical conclusion to this RFC. Could please let me know the further updates on these requirements? Thanks in Advance Best Regards Soby Mathew -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Preliminary proposal, new APIs for HDMI and DVI control in v4l2
This is a preliminary proposal for an extension to the v4l2 api.
To be discussed at the V4L2 'brainstorming' meeting in Warsaw, March 2011
Purpose: Provide basic controls for HDMI and DVI devices.
sink : HDMI/DVI/VGA receiver
source: HDMI/DVI/VGA transmitter
New Controls:
=
These controls rely on control events to be able to notify the
application of any change.
The idea is to create an event that will be triggered by the control
framework whenever a control changes value.
TX source:
--
Control: V4L2_CID_DV_TX_HOTPLUG
type: bitmask (output), read only
name: Hotplug
Hotplug is present on each output.
The hotplug is issued by the sink to indicate that an
edid exists and should be read by the source.
Not applicable for VGA connectors.
Control: V4L2_CID_DV_TX_RXSENSE
type: bitmask (output), read only
name: Rx Sense
Rx sense is present on each output.
Rx Sense is detection of pull-ups on the TMDS clock lines.
Normally means that the sink has left/entered standby.
Not applicable for VGA connectors.
Control: V4L2_CID_DV_TX_EDID_SEGMENT0_PRESENT
type: bitmask (output), read only
name: Edid segment 0
The source driver has read edid segment 0 from the sink.
Control: V4L2_CID_DV_TX_DVI_HDMI_MODE
type: menu, read and write
name: Hdmi/Dvi mode
Settings:
HDMI
DVI-D
RX sink:
Control: V4L2_CID_DV_RX_5V
type: bitmask (input), read only
name: Rx 5V
The source must supply the sink with a +5v via the HDMI/DVI cable.
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.
Control: V4L2_CID_DV_CABLE_DETECT
type: bitmask (input), read only
name: Cable detect
This is not a part of the HDMI/DVI standards.
But many sinks (read monitors) uses a + 5v pull-up on a
ground pin (typically pin 15 on dvi) to detect if a cable is
is connected and terminated at the source end.
Control: V4L2_CID_DV_FORMAT_STATUS
type: menu, read only
name: Format status
Format status for the current selected input.
Statuses:
No signal
Unknown
Unsupported
Encrypted
Valid/supported
The input signal has changed format or status.
In the case of a valid signal use the
vidioc_query_dv_preset to read the new format.
Alternatively this could also be implemented as a bitmask with bits
for: 'signal present', 'encrypted', 'supported format'.
Or as three separate boolean controls.
New Events:
===
V4L2_EVENT_TX_EDID
struct v4l2_event_tx_edid {
__u32 output;
__u32 present;
__u32 segment;
}
The source driver has read an edid segment from the sink.
One segment is 256 bytes and will contain one or two 128
bytes blocks. Most HDMI and DVI sinks will have only segment 0.
The driver should read segment 0 when hotplug is detected and
report this to userspace. The application can then use the
V4L2_G_EDID ioctl to get the actual edid data.
If the EDID data indicates the presence of further extension blocks the
userspace application can use the V4L2_REQ_EDID ioctl to trigger a read.
When the driver has read that extended segment it will generate a
V4L2_EVENT_TX_EDID event.
New Ioctls:
===
TX source:
--
V4L2_REQ_EDID
struct v4l2_req_edid {
__u32 output;
__u32 segment;
}
Trigger a read of a 256 bytes segment. Normally the driver will
read segment 0 by itself when hotplug is detected, But this ioctl
may also be used to trigger a re-read of segment 0.
V4L2_G_EDID
struct v4l2_g_edid {
__u32 output;
__u32 segment;
__u8 edid[256];
}
Get the edid segment indicated in the V4L2_EVENT_TX_EDID
RX sink:
V4L2_S_EDID
struct v4l2_s_edid {
__u32 input;
__u32 segment;
__u8 _edid[256];
}
Set the edid information in the source.
Additional Controls and Status:
===
Controls and statuses we want to add.
Currently based on HDMI version 1.3a, must be updated
From Info frames
* Y0, Y1 RGB or YCBCR indicator.
* A0Active Information Present. Indicates whether field
R0...R3 is valid. See
CEA-861-D table 8 for details.
* B0, B1Bar Info data valid. See CEA-861-D table 8 for details.
HDMI Licensing, LLC Page 113 of 156
High-Definition Multimedia Interface
Specification Version 1.3a
* S0, S1Scan Information (i.e. overscan, underscan). See
CEA-861-D table 8 for
details.
* C0, C1Colorimetry (ITU BT.601, BT.709 etc.). See CEA-861-D
table 9 for
details.
* EC0, EC1, EC2 Extended Colorimetry (IEC 61966-2-4 etc.). See
