On 3/9/20 2:56 PM, Sakari Ailus wrote:
> Hi Hans,
>
> On Mon, Mar 09, 2020 at 02:53:15PM +0100, Hans Verkuil wrote:
>> On 3/9/20 2:47 PM, Sakari Ailus wrote:
>>> Hi Niklas,
>>>
>>> Thanks for the update!
>>>
>>> On Fri, Mar 06, 2020 at 05:39:33PM +0100, Niklas Söderlund wrote:
>>>> From: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>>
>>>> Add a video device capability flag to indicate that its inputs and/or
>>>> outputs are controlled by the Media Controller instead of the V4L2 API.
>>>> When this flag is set, ioctl for enum inputs and outputs are
>>>> automatically enabled and programmed to call a helper function.
>>>>
>>>> Suggested-by: Hans Verkuil <hverkuil@xxxxxxxxx>
>>>> Signed-off-by: Helen Koike <helen.koike@xxxxxxxxxxxxx>
>>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
>>>> ---
>>>> * Changes since v3
>>>> - Update documentation for V4L2_CAP_IO_MC
>>>> - Only enable VIDIOC_{G,S}_{INPUT,OUTPUT} if V4L2_CAP_IO_MC is set
>>>> (instead of unconditionally)
>>>> - Merge v4l2_ioctl_enum_input_mc() into v4l_enuminput()
>>>> - Merge v4l2_ioctl_enum_output_mc() into v4l_enumoutput()
>>>>
>>>> * Changes since v2
>>>> - Merged the two patches touching V4L2 core stuff to a single patch.
>>>> - Updated documentation for V4L2_CAP_IO_MC
>>>> - Added is_io_mc bool in determine_valid_ioctls()
>>>> - Folded or moved code closer to where it's used
>>>> - Remove unneeded memset()
>>>> - Use strscpy() instead of strlcpy()
>>>> ---
>>>> .../media/uapi/v4l/vidioc-querycap.rst | 6 ++
>>>> .../media/videodev2.h.rst.exceptions | 1 +
>>>> drivers/media/v4l2-core/v4l2-dev.c | 25 ++++++--
>>>> drivers/media/v4l2-core/v4l2-ioctl.c | 57 +++++++++++++++++--
>>>> include/uapi/linux/videodev2.h | 2 +
>>>> 5 files changed, 81 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst
>>>> index 5f9930195d624c73..497a6aa2cbebad71 100644
>>>> --- a/Documentation/media/uapi/v4l/vidioc-querycap.rst
>>>> +++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst
>>>> @@ -264,6 +264,12 @@ specification the ioctl returns an ``EINVAL`` error code.
>>>> * - ``V4L2_CAP_TOUCH``
>>>> - 0x10000000
>>>> - This is a touch device.
>>>> + * - ``V4L2_CAP_IO_MC``
>>>> + - 0x20000000
>>>> + - There is only one input and/or output seen from userspace. The whole
>>>> + video topology configuration, including which I/O entity is routed to
>>>> + the input/output, is configured by userspace via the Media Controller.
>>>> + See :ref:`media_controller`.
>>>> * - ``V4L2_CAP_DEVICE_CAPS``
>>>> - 0x80000000
>>>> - The driver fills the ``device_caps`` field. This capability can
>>>> diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions
>>>> index cb6ccf91776e6b56..a625fb90e3a989a7 100644
>>>> --- a/Documentation/media/videodev2.h.rst.exceptions
>>>> +++ b/Documentation/media/videodev2.h.rst.exceptions
>>>> @@ -176,6 +176,7 @@ replace define V4L2_CAP_STREAMING device-capabilities
>>>> replace define V4L2_CAP_META_OUTPUT device-capabilities
>>>> replace define V4L2_CAP_DEVICE_CAPS device-capabilities
>>>> replace define V4L2_CAP_TOUCH device-capabilities
>>>> +replace define V4L2_CAP_IO_MC device-capabilities
>>>>
>>>> # V4L2 pix flags
>>>> replace define V4L2_PIX_FMT_PRIV_MAGIC :c:type:`v4l2_pix_format`
>>>> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
>>>> index 97b6a3af13614639..a593ea0598b551b4 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-dev.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-dev.c
>>>> @@ -552,6 +552,7 @@ static void determine_valid_ioctls(struct video_device *vdev)
>>>> (vdev->device_caps & meta_caps);
>>>> bool is_rx = vdev->vfl_dir != VFL_DIR_TX;
>>>> bool is_tx = vdev->vfl_dir != VFL_DIR_RX;
>>>> + bool is_io_mc = vdev->device_caps & V4L2_CAP_IO_MC;
>>>>
>>>> bitmap_zero(valid_ioctls, BASE_VIDIOC_PRIVATE);
>>>>
>>>> @@ -725,9 +726,15 @@ static void determine_valid_ioctls(struct video_device *vdev)
>>>> SET_VALID_IOCTL(ops, VIDIOC_G_STD, vidioc_g_std);
>>>> if (is_rx) {
>>>> SET_VALID_IOCTL(ops, VIDIOC_QUERYSTD, vidioc_querystd);
>>>> - SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
>>>> - SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
>>>> - SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
>>>> + if (is_io_mc) {
>>>> + set_bit(_IOC_NR(VIDIOC_ENUMINPUT), valid_ioctls);
>>>> + set_bit(_IOC_NR(VIDIOC_G_INPUT), valid_ioctls);
>>>> + set_bit(_IOC_NR(VIDIOC_S_INPUT), valid_ioctls);
>>>> + } else {
>>>> + SET_VALID_IOCTL(ops, VIDIOC_ENUMINPUT, vidioc_enum_input);
>>>> + SET_VALID_IOCTL(ops, VIDIOC_G_INPUT, vidioc_g_input);
>>>> + SET_VALID_IOCTL(ops, VIDIOC_S_INPUT, vidioc_s_input);
>>>> + }
>>>> SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDIO, vidioc_enumaudio);
>>>> SET_VALID_IOCTL(ops, VIDIOC_G_AUDIO, vidioc_g_audio);
>>>> SET_VALID_IOCTL(ops, VIDIOC_S_AUDIO, vidioc_s_audio);
>>>> @@ -735,9 +742,15 @@ static void determine_valid_ioctls(struct video_device *vdev)
>>>> SET_VALID_IOCTL(ops, VIDIOC_S_EDID, vidioc_s_edid);
>>>> }
>>>> if (is_tx) {
>>>> - SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
>>>> - SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
>>>> - SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
>>>> + if (is_io_mc) {
>>>> + set_bit(_IOC_NR(VIDIOC_ENUMOUTPUT), valid_ioctls);
>>>> + set_bit(_IOC_NR(VIDIOC_G_OUTPUT), valid_ioctls);
>>>> + set_bit(_IOC_NR(VIDIOC_S_OUTPUT), valid_ioctls);
>>>> + } else {
>>>> + SET_VALID_IOCTL(ops, VIDIOC_ENUMOUTPUT, vidioc_enum_output);
>>>> + SET_VALID_IOCTL(ops, VIDIOC_G_OUTPUT, vidioc_g_output);
>>>> + SET_VALID_IOCTL(ops, VIDIOC_S_OUTPUT, vidioc_s_output);
>>>> + }
>>>> SET_VALID_IOCTL(ops, VIDIOC_ENUMAUDOUT, vidioc_enumaudout);
>>>> SET_VALID_IOCTL(ops, VIDIOC_G_AUDOUT, vidioc_g_audout);
>>>> SET_VALID_IOCTL(ops, VIDIOC_S_AUDOUT, vidioc_s_audout);
>>>> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> index fbcc7a20eedf553a..58e9e728f0a7aa4b 100644
>>>> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
>>>> @@ -1085,6 +1085,32 @@ static int v4l_querycap(const struct v4l2_ioctl_ops *ops,
>>>> return ret;
>>>> }
>>>>
>>>> +static int v4l_g_input(const struct v4l2_ioctl_ops *ops,
>>>> + struct file *file, void *fh, void *arg)
>>>> +{
>>>> + struct video_device *vfd = video_devdata(file);
>>>> +
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC) {
>>>> + *(unsigned int *)arg = 0;
>>>> + return 0;
>>>> + }
>>>> +
>>>> + return ops->vidioc_g_input(file, fh, arg);
>>>> +}
>>>> +
>>>> +static int v4l_g_output(const struct v4l2_ioctl_ops *ops,
>>>> + struct file *file, void *fh, void *arg)
>>>> +{
>>>> + struct video_device *vfd = video_devdata(file);
>>>> +
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC) {
>>>> + *(unsigned int *)arg = 0;
>>>> + return 0;
>>>> + }
>>>> +
>>>> + return ops->vidioc_g_output(file, fh, arg);
>>>> +}
>>>> +
>>>> static int v4l_s_input(const struct v4l2_ioctl_ops *ops,
>>>> struct file *file, void *fh, void *arg)
>>>> {
>>>> @@ -1094,12 +1120,21 @@ static int v4l_s_input(const struct v4l2_ioctl_ops *ops,
>>>> ret = v4l_enable_media_source(vfd);
>>>> if (ret)
>>>> return ret;
>>>> +
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC)
>>>> + return *(unsigned int *)arg ? -EINVAL : 0;
>>>> +
>>>> return ops->vidioc_s_input(file, fh, *(unsigned int *)arg);
>>>> }
>>>>
>>>> static int v4l_s_output(const struct v4l2_ioctl_ops *ops,
>>>> struct file *file, void *fh, void *arg)
>>>> {
>>>> + struct video_device *vfd = video_devdata(file);
>>>> +
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC)
>>>> + return *(unsigned int *)arg ? -EINVAL : 0;
>>>
>>> The type is int, not unsigned int. The same on the rest above.
>>>
>>>> +
>>>> return ops->vidioc_s_output(file, fh, *(unsigned int *)arg);
>>>> }
>>>>
>>>> @@ -1143,6 +1178,14 @@ static int v4l_enuminput(const struct v4l2_ioctl_ops *ops,
>>>> if (is_valid_ioctl(vfd, VIDIOC_S_STD))
>>>> p->capabilities |= V4L2_IN_CAP_STD;
>>>>
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC) {
>>>> + if (p->index)
>>>> + return -EINVAL;
>>>> + strscpy(p->name, vfd->name, sizeof(p->name));
>>>> + p->type = V4L2_INPUT_TYPE_CAMERA;
>>>> + return 0;
>>>> + }
>>>> +
>>>> return ops->vidioc_enum_input(file, fh, p);
>>>> }
>>>>
>>>> @@ -1161,6 +1204,14 @@ static int v4l_enumoutput(const struct v4l2_ioctl_ops *ops,
>>>> if (is_valid_ioctl(vfd, VIDIOC_S_STD))
>>>> p->capabilities |= V4L2_OUT_CAP_STD;
>>>>
>>>> + if (vfd->device_caps & V4L2_CAP_IO_MC) {
>>>> + if (p->index)
>>>> + return -EINVAL;
>>>> + strscpy(p->name, vfd->name, sizeof(p->name));
>>>> + p->type = V4L2_OUTPUT_TYPE_ANALOG;
>>>
>>> How about adding a new INPUT and OUTPUT types just for IO_MC device cap?
>>
>> V4L2_OUTPUT_TYPE_ANALOG is an old term that is in practice used for anything video,
>> except for TV modulators. I'm all in favor of changing this to:
>>
>> #define V4L2_OUTPUT_TYPE_VIDEO 2
>> #ifndef __KERNEL__
>> #define V4L2_OUTPUT_TYPE_ANALOG V4L2_OUTPUT_TYPE_VIDEO
>> #endif
>>
>> in videodev2.h, if others agree with that. But that can be done in a separate
>> follow-up patch since this needs to be adapted throughout the kernel & documentation.
>>
>> The same is true for V4L2_INPUT_TYPE_CAMERA: in practice it's used for any video,
>> except TV tuners.
>
> My point was rather that here, we don't know what kind of device really is
> the source (or the sink) of the data path. Having a designated input and
> output type for that would be entirely appropriate.
But that's exactly what V4L2_OUTPUT_TYPE_ANALOG/V4L2_INPUT_TYPE_CAMERA means:
it's some kind of video, but we don't know what.
That's why these names are so misleading: they suggest a particular type,
but in reality they don't.
So V4L2_IN/OUTPUT_TYPE_VIDEO is what you want for MC inputs/outputs, but that's
just an alias for V4L2_INPUT_TYPE_CAMERA/V4L2_OUTPUT_TYPE_ANALOG.
Regards,
Hans
>
> Although if the user gets a misleading value using an interface that
> (s)he's not supposed to use to begin with, I guess I'd fine with that as
> well.
>
