Re: [PATCH v2 2/2] v4l: Add support for STD ioctls on subdev nodes

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[adding Marco Felsch since he has been working on this driver]

On 07/05/2018 03:12 PM, Hans Verkuil wrote:
> On 05/07/18 14:44, Mauro Carvalho Chehab wrote:
>> Javier,
>>
>> How standard settings work with the current OMAP3 drivers with tvp5150?
> 
> It looks like tvp5150 uses autodetect of the standard, which in general is

That's correct, the driver uses standard autodetect.

> not a good thing to do since different standards have different buffer
> sizes. But this chip can scale, so it might scale PAL to NTSC or vice versa
> if the standard switches mid-stream. Or it only detects the standard when
> it starts streaming, I'm not sure.
>

Not sure about this either, IIUC switching the standard mid-stream won't work.

> In any case, this is not normal behavior, for almost all analog video
> receivers you need to be able to set the std explicitly.
>

Indeed. I see that Marco's recent series [0] add supports for the .querystd [1]
and .g_std [2] callbacks to the tvp5150 driver, so that way user-space can get
back the detected standard.

[0]: https://www.spinics.net/lists/linux-media/msg136869.html
[1]: https://www.spinics.net/lists/linux-media/msg136872.html
[2]: https://www.spinics.net/lists/linux-media/msg136875.html

> Regards,
> 
> 	Hans
>

Best regards,
-- 
Javier Martinez Canillas
Software Engineer - Desktop Hardware Enablement
Red Hat

>>
>> Regards,
>> Mauro
>>
>>
>> Em Thu, 17 May 2018 16:30:16 +0200
>> Niklas Söderlund         <niklas.soderlund+renesas@xxxxxxxxxxxx> escreveu:
>>
>>> There is no way to control the standard of subdevices which are part of
>>> a media device. The ioctls which exists all target video devices
>>> explicitly and the idea is that the video device should talk to the
>>> subdevice. For subdevices part of a media graph this is not possible and
>>> the standard must be controlled on the subdev device directly.
>>>
>>> Add four new ioctls to be able to directly interact with subdevices and
>>> control the video standard; VIDIOC_SUBDEV_ENUMSTD, VIDIOC_SUBDEV_G_STD,
>>> VIDIOC_SUBDEV_S_STD and VIDIOC_SUBDEV_QUERYSTD.
>>>
>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>
>>> ---
>>>
>>> * Changes since v1
>>> - Added VIDIOC_SUBDEV_ENUMSTD.
>>> ---
>>>  .../media/uapi/v4l/vidioc-enumstd.rst         | 11 ++++++----
>>>  Documentation/media/uapi/v4l/vidioc-g-std.rst | 14 ++++++++----
>>>  .../media/uapi/v4l/vidioc-querystd.rst        | 11 ++++++----
>>>  drivers/media/v4l2-core/v4l2-subdev.c         | 22 +++++++++++++++++++
>>>  include/uapi/linux/v4l2-subdev.h              |  4 ++++
>>>  5 files changed, 50 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/Documentation/media/uapi/v4l/vidioc-enumstd.rst b/Documentation/media/uapi/v4l/vidioc-enumstd.rst
>>> index b7fda29f46a139a0..2644a62acd4b6822 100644
>>> --- a/Documentation/media/uapi/v4l/vidioc-enumstd.rst
>>> +++ b/Documentation/media/uapi/v4l/vidioc-enumstd.rst
>>> @@ -2,14 +2,14 @@
>>>  
>>>  .. _VIDIOC_ENUMSTD:
>>>  
>>> -********************
>>> -ioctl VIDIOC_ENUMSTD
>>> -********************
>>> +*******************************************
>>> +ioctl VIDIOC_ENUMSTD, VIDIOC_SUBDEV_ENUMSTD
>>> +*******************************************
>>>  
>>>  Name
>>>  ====
>>>  
>>> -VIDIOC_ENUMSTD - Enumerate supported video standards
>>> +VIDIOC_ENUMSTD - VIDIOC_SUBDEV_ENUMSTD - Enumerate supported video standards
>>>  
>>>  
>>>  Synopsis
>>> @@ -18,6 +18,9 @@ Synopsis
>>>  .. c:function:: int ioctl( int fd, VIDIOC_ENUMSTD, struct v4l2_standard *argp )
>>>      :name: VIDIOC_ENUMSTD
>>>  
>>> +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_ENUMSTD, struct v4l2_standard *argp )
>>> +    :name: VIDIOC_SUBDEV_ENUMSTD
>>> +
>>>  
>>>  Arguments
>>>  =========
>>> diff --git a/Documentation/media/uapi/v4l/vidioc-g-std.rst b/Documentation/media/uapi/v4l/vidioc-g-std.rst
>>> index 90791ab51a5371b8..8d94f0404df270db 100644
>>> --- a/Documentation/media/uapi/v4l/vidioc-g-std.rst
>>> +++ b/Documentation/media/uapi/v4l/vidioc-g-std.rst
>>> @@ -2,14 +2,14 @@
>>>  
>>>  .. _VIDIOC_G_STD:
>>>  
>>> -********************************
>>> -ioctl VIDIOC_G_STD, VIDIOC_S_STD
>>> -********************************
>>> +**************************************************************************
>>> +ioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDEV_G_STD, VIDIOC_SUBDEV_S_STD
>>> +**************************************************************************
>>>  
>>>  Name
>>>  ====
>>>  
>>> -VIDIOC_G_STD - VIDIOC_S_STD - Query or select the video standard of the current input
>>> +VIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_STD - VIDIOC_SUBDEV_S_STD - Query or select the video standard of the current input
>>>  
>>>  
>>>  Synopsis
>>> @@ -21,6 +21,12 @@ Synopsis
>>>  .. c:function:: int ioctl( int fd, VIDIOC_S_STD, const v4l2_std_id *argp )
>>>      :name: VIDIOC_S_STD
>>>  
>>> +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_STD, v4l2_std_id *argp )
>>> +    :name: VIDIOC_SUBDEV_G_STD
>>> +
>>> +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_STD, const v4l2_std_id *argp )
>>> +    :name: VIDIOC_SUBDEV_S_STD
>>> +
>>>  
>>>  Arguments
>>>  =========
>>> diff --git a/Documentation/media/uapi/v4l/vidioc-querystd.rst b/Documentation/media/uapi/v4l/vidioc-querystd.rst
>>> index cf40bca19b9f8665..a8385cc7481869dd 100644
>>> --- a/Documentation/media/uapi/v4l/vidioc-querystd.rst
>>> +++ b/Documentation/media/uapi/v4l/vidioc-querystd.rst
>>> @@ -2,14 +2,14 @@
>>>  
>>>  .. _VIDIOC_QUERYSTD:
>>>  
>>> -*********************
>>> -ioctl VIDIOC_QUERYSTD
>>> -*********************
>>> +*********************************************
>>> +ioctl VIDIOC_QUERYSTD, VIDIOC_SUBDEV_QUERYSTD
>>> +*********************************************
>>>  
>>>  Name
>>>  ====
>>>  
>>> -VIDIOC_QUERYSTD - Sense the video standard received by the current input
>>> +VIDIOC_QUERYSTD - VIDIOC_SUBDEV_QUERYSTD - Sense the video standard received by the current input
>>>  
>>>  
>>>  Synopsis
>>> @@ -18,6 +18,9 @@ Synopsis
>>>  .. c:function:: int ioctl( int fd, VIDIOC_QUERYSTD, v4l2_std_id *argp )
>>>      :name: VIDIOC_QUERYSTD
>>>  
>>> +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_QUERYSTD, v4l2_std_id *argp )
>>> +    :name: VIDIOC_SUBDEV_QUERYSTD
>>> +
>>>  
>>>  Arguments
>>>  =========
>>> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
>>> index f9eed938d3480b74..27a2c633f2323f5f 100644
>>> --- a/drivers/media/v4l2-core/v4l2-subdev.c
>>> +++ b/drivers/media/v4l2-core/v4l2-subdev.c
>>> @@ -494,6 +494,28 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
>>>  
>>>  	case VIDIOC_SUBDEV_S_DV_TIMINGS:
>>>  		return v4l2_subdev_call(sd, video, s_dv_timings, arg);
>>> +
>>> +	case VIDIOC_SUBDEV_G_STD:
>>> +		return v4l2_subdev_call(sd, video, g_std, arg);
>>> +
>>> +	case VIDIOC_SUBDEV_S_STD: {
>>> +		v4l2_std_id *std = arg;
>>> +
>>> +		return v4l2_subdev_call(sd, video, s_std, *std);
>>> +	}
>>> +
>>> +	case VIDIOC_SUBDEV_ENUMSTD: {
>>> +		struct v4l2_standard *p = arg;
>>> +		v4l2_std_id id;
>>> +
>>> +		if (v4l2_subdev_call(sd, video, g_tvnorms, &id))
>>> +			return -EINVAL;
>>> +
>>> +		return v4l_video_std_enumstd(p, id);
>>> +	}
>>> +
>>> +	case VIDIOC_SUBDEV_QUERYSTD:
>>> +		return v4l2_subdev_call(sd, video, querystd, arg);
>>>  #endif
>>>  	default:
>>>  		return v4l2_subdev_call(sd, core, ioctl, cmd, arg);
>>> diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
>>> index c95a53e6743cb040..03970ce3074193e6 100644
>>> --- a/include/uapi/linux/v4l2-subdev.h
>>> +++ b/include/uapi/linux/v4l2-subdev.h
>>> @@ -170,8 +170,12 @@ struct v4l2_subdev_selection {
>>>  #define VIDIOC_SUBDEV_G_SELECTION		_IOWR('V', 61, struct v4l2_subdev_selection)
>>>  #define VIDIOC_SUBDEV_S_SELECTION		_IOWR('V', 62, struct v4l2_subdev_selection)
>>>  /* The following ioctls are identical to the ioctls in videodev2.h */
>>> +#define VIDIOC_SUBDEV_G_STD			_IOR('V', 23, v4l2_std_id)
>>> +#define VIDIOC_SUBDEV_S_STD			_IOW('V', 24, v4l2_std_id)
>>> +#define VIDIOC_SUBDEV_ENUMSTD			_IOWR('V', 25, struct v4l2_standard)
>>>  #define VIDIOC_SUBDEV_G_EDID			_IOWR('V', 40, struct v4l2_edid)
>>>  #define VIDIOC_SUBDEV_S_EDID			_IOWR('V', 41, struct v4l2_edid)
>>> +#define VIDIOC_SUBDEV_QUERYSTD			_IOR('V', 63, v4l2_std_id)
>>>  #define VIDIOC_SUBDEV_S_DV_TIMINGS		_IOWR('V', 87, struct v4l2_dv_timings)
>>>  #define VIDIOC_SUBDEV_G_DV_TIMINGS		_IOWR('V', 88, struct v4l2_dv_timings)
>>>  #define VIDIOC_SUBDEV_ENUM_DV_TIMINGS		_IOWR('V', 98, struct v4l2_enum_dv_timings)
>>
>>
>>
>> Thanks,
>> Mauro
>>
> 





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