[PATCH v7 0/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[PATCH v7 0/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[Niklas Söderlund]

Hi,

This series aims to reduce the amount of boiler plate code in video
device drivers who's inputs and/or outputs are controlled by the Media
Controller instead of the V4L2 API.

Patch 1/6 adds a new video device capability flag V4L2_CAP_IO_MC which
if set provides helper implementations for the enum inputs and outputs
ioctls freeing the video device driver from the need to implement them.

Patch 2/6 fix initialization of reserved fields in the ivtv driver which 
becomes a problem in 3/6 where Laurent adds mbus filters to 
VIDIOC_ENUM_FMT.

Patch 4/6, 5/6 and 6/6 converts the R-Car VIN, Intel IPU3 and VIMC
drivers to use the new default handlers and capability flag and delete
the now redundant boiler plate code. I'm sure more video device drivers
can make use of this new flag but as I can only test on these two
platforms I have limited my changes to those.

A separate patch to v4l-utils have been posted as [1] to add a
test for this feature in v4l2-compliance.

1. [PATCH 0/2] v4l2-compliance: add tests for V4L2_CAP_IO_MC

Laurent Pinchart (1):
  media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

Niklas Söderlund (5):
  v4l2-dev/ioctl: Add V4L2_CAP_IO_MC
  ivtv-ioctl.c: Do not initialize the reserved field of struct
    v4l2_fmtdesc
  rcar-vin: Make use of V4L2_CAP_IO_MC
  staging/intel-ipu3: Make use of V4L2_CAP_IO_MC
  vimc: Make use of V4L2_CAP_IO_MC

 .../media/uapi/v4l/vidioc-enum-fmt.rst        | 17 ++++-
 .../media/uapi/v4l/vidioc-querycap.rst        |  6 ++
 .../media/videodev2.h.rst.exceptions          |  1 +
 drivers/media/pci/ivtv/ivtv-ioctl.c           |  4 --
 drivers/media/platform/rcar-vin/rcar-v4l2.c   | 40 ++++++-----
 drivers/media/platform/vimc/vimc-capture.c    | 10 ++-
 drivers/media/v4l2-core/v4l2-dev.c            | 25 +++++--
 drivers/media/v4l2-core/v4l2-ioctl.c          | 70 +++++++++++++++++--
 drivers/staging/media/ipu3/ipu3-v4l2.c        | 64 ++---------------
 include/uapi/linux/videodev2.h                |  5 +-
 10 files changed, 147 insertions(+), 95 deletions(-)

-- 
2.26.0

[PATCH v7 1/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[Niklas Söderlund]

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@xs4all.nl>
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../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..3048811450182185 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 && !is_meta) {
+				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 && !is_meta) {
+				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 b2ef8e60ea7da19d..afd1f427df557f71 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) {
+		*(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) {
+		*(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  *(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  *(int *)arg ? -EINVAL : 0;
+
 	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;
+		return 0;
+	}
+
 	return ops->vidioc_enum_output(file, fh, p);
 }
 
@@ -2683,10 +2734,8 @@ DEFINE_V4L_STUB_FUNC(expbuf)
 DEFINE_V4L_STUB_FUNC(g_std)
 DEFINE_V4L_STUB_FUNC(g_audio)
 DEFINE_V4L_STUB_FUNC(s_audio)
-DEFINE_V4L_STUB_FUNC(g_input)
 DEFINE_V4L_STUB_FUNC(g_edid)
 DEFINE_V4L_STUB_FUNC(s_edid)
-DEFINE_V4L_STUB_FUNC(g_output)
 DEFINE_V4L_STUB_FUNC(g_audout)
 DEFINE_V4L_STUB_FUNC(s_audout)
 DEFINE_V4L_STUB_FUNC(g_jpegcomp)
@@ -2735,11 +2784,11 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = {
 	IOCTL_INFO(VIDIOC_S_AUDIO, v4l_stub_s_audio, v4l_print_audio, INFO_FL_PRIO),
 	IOCTL_INFO(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)),
 	IOCTL_INFO(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)),
-	IOCTL_INFO(VIDIOC_G_INPUT, v4l_stub_g_input, v4l_print_u32, 0),
+	IOCTL_INFO(VIDIOC_G_INPUT, v4l_g_input, v4l_print_u32, 0),
 	IOCTL_INFO(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO),
 	IOCTL_INFO(VIDIOC_G_EDID, v4l_stub_g_edid, v4l_print_edid, INFO_FL_ALWAYS_COPY),
 	IOCTL_INFO(VIDIOC_S_EDID, v4l_stub_s_edid, v4l_print_edid, INFO_FL_PRIO | INFO_FL_ALWAYS_COPY),
-	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_stub_g_output, v4l_print_u32, 0),
+	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_g_output, v4l_print_u32, 0),
 	IOCTL_INFO(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO),
 	IOCTL_INFO(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)),
 	IOCTL_INFO(VIDIOC_G_AUDOUT, v4l_stub_g_audout, v4l_print_audioout, 0),
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 9817b7e2c968fd04..b18f3f7cde31c2e4 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -487,6 +487,8 @@ struct v4l2_capability {
 
 #define V4L2_CAP_TOUCH                  0x10000000  /* Is a touch device */
 
+#define V4L2_CAP_IO_MC			0x20000000  /* Is input/output controlled by the media controller */
+
 #define V4L2_CAP_DEVICE_CAPS            0x80000000  /* sets device capabilities field */
 
 /*
-- 
2.26.0

[PATCH v7 2/6] ivtv-ioctl.c: Do not initialize the reserved field of struct v4l2_fmtdesc

[Niklas Söderlund]

One of the reserved fields are about to be used. Instead of updating the
driver to only initialize three instead of four reserved fields remove
the explicit assignment.  As if one field in a struct is assigned, the
memory is zeroed and explicit assignment is redundant.

Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
---
 drivers/media/pci/ivtv/ivtv-ioctl.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/media/pci/ivtv/ivtv-ioctl.c b/drivers/media/pci/ivtv/ivtv-ioctl.c
index 137853944e4619cb..8a45c50411c74831 100644
--- a/drivers/media/pci/ivtv/ivtv-ioctl.c
+++ b/drivers/media/pci/ivtv/ivtv-ioctl.c
@@ -922,12 +922,10 @@ static int ivtv_enum_fmt_vid_cap(struct file *file, void *fh, struct v4l2_fmtdes
 	static const struct v4l2_fmtdesc hm12 = {
 		0, V4L2_BUF_TYPE_VIDEO_CAPTURE, 0,
 		"HM12 (YUV 4:2:0)", V4L2_PIX_FMT_HM12,
-		{ 0, 0, 0, 0 }
 	};
 	static const struct v4l2_fmtdesc mpeg = {
 		0, V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FMT_FLAG_COMPRESSED,
 		"MPEG", V4L2_PIX_FMT_MPEG,
-		{ 0, 0, 0, 0 }
 	};
 	struct ivtv *itv = fh2id(fh)->itv;
 	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
@@ -948,12 +946,10 @@ static int ivtv_enum_fmt_vid_out(struct file *file, void *fh, struct v4l2_fmtdes
 	static const struct v4l2_fmtdesc hm12 = {
 		0, V4L2_BUF_TYPE_VIDEO_OUTPUT, 0,
 		"HM12 (YUV 4:2:0)", V4L2_PIX_FMT_HM12,
-		{ 0, 0, 0, 0 }
 	};
 	static const struct v4l2_fmtdesc mpeg = {
 		0, V4L2_BUF_TYPE_VIDEO_OUTPUT, V4L2_FMT_FLAG_COMPRESSED,
 		"MPEG", V4L2_PIX_FMT_MPEG,
-		{ 0, 0, 0, 0 }
 	};
 	struct ivtv *itv = fh2id(fh)->itv;
 	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
-- 
2.26.0

[PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Niklas Söderlund]

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
node. For MC-centric devices, its behaviour has always been ill-defined,
with drivers implementing one of the following behaviours:

- No support for VIDIOC_ENUM_FMT at all
- Enumerating all formats supported by the video node, regardless of the
  configuration of the pipeline
- Enumerating formats supported by the video node for the active
  configuration of the connected subdevice

The first behaviour is obviously useless for applications. The second
behaviour provides the most information, but doesn't offer a way to find
what formats are compatible with a given pipeline configuration. The
third behaviour fixes that, but with the drawback that applications
can't enumerate all supported formats anymore, and have to modify the
active configuration of the pipeline to enumerate formats.

The situation is messy as none of the implemented behaviours are ideal,
and userspace can't predict what will happen as the behaviour is
driver-specific.

To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
enumerating pixel formats for a given media bus code. The media bus code
is passed through the v4l2_fmtdesc structure in a new mbus_code field
(repurposed from the reserved fields). With this capability in place,
applications can enumerate pixel formats for a given media bus code
without modifying the active configuration of the device.

The current behaviour of the ioctl is preserved when the new mbus_code
field is set to 0, ensuring compatibility with existing userspace. The
API extension is documented as mandatory for MC-centric devices (as
advertised through the V4L2_CAP_IO_MC capability), allowing applications
and compliance tools to easily determine the availability of the
VIDIOC_ENUM_FMT extension.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
 drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
 include/uapi/linux/videodev2.h                  |  3 ++-
 3 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
index 8ca6ab701e4ab99c..82792d8e910b2313 100644
--- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
+++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
@@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
 formats in preference order, where preferred formats are returned before
 (that is, with lower ``index`` value) less-preferred formats.
 
-.. note::
+If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
+:ref:`device-capabilities <capability>`, applications shall initialize the
+``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
+by the device. The enumerated formats may depend on the active input or output
+of the device.
 
-   After switching input or output the list of enumerated image
-   formats may be different.
+If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
+<capability>`, applications may initialize the ``mbus_code`` to a valid
+:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
+is not zero, drivers shall restrict enumeration to only the image formats that
+can produce (for video output devices) or be produced from (for video capture
+devices) that media bus code. Regardless of the value of the ``mbus_code``
+field, the enumerated image formats shall not depend on the active
+configuration of the video device or device pipeline. Enumeration shall
+otherwise operate as previously described.
 
 
 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index afd1f427df557f71..3e7b99fa415222c6 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
 {
 	const struct v4l2_fmtdesc *p = arg;
 
-	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
+	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
 		p->index, prt_names(p->type, v4l2_type_names),
 		p->flags, (p->pixelformat & 0xff),
 		(p->pixelformat >>  8) & 0xff,
 		(p->pixelformat >> 16) & 0xff,
 		(p->pixelformat >> 24) & 0xff,
+		p->mbus_code,
 		(int)sizeof(p->description), p->description);
 }
 
@@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
 	struct video_device *vdev = video_devdata(file);
 	struct v4l2_fmtdesc *p = arg;
 	int ret = check_fmt(file, p->type);
+	u32 mbus_code;
 	u32 cap_mask;
 
 	if (ret)
 		return ret;
 	ret = -EINVAL;
 
+	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
+		return -EINVAL;
+
+	mbus_code = p->mbus_code;
+	CLEAR_AFTER_FIELD(p, type);
+	p->mbus_code = mbus_code;
+
 	switch (p->type) {
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
 	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
@@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
 
 static const struct v4l2_ioctl_info v4l2_ioctls[] = {
 	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
-	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
+	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
 	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
 	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
 	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
 	__u32               flags;
 	__u8		    description[32];   /* Description string */
 	__u32		    pixelformat;       /* Format fourcc      */
-	__u32		    reserved[4];
+	__u32		    mbus_code;		/* Media bus code    */
+	__u32		    reserved[3];
 };
 
 #define V4L2_FMT_FLAG_COMPRESSED		0x0001
-- 
2.26.0

[PATCH v7 4/6] rcar-vin: Make use of V4L2_CAP_IO_MC

[Niklas Söderlund]

Set the V4L2_CAP_IO_MC capability flag and remove the driver specific
vidioc_enum_input, vidioc_g_input and vidioc_s_input callbacks for the
media controller enabled part of the driver. Also add support mbus_code
filtering for format enumeration.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
* Changes since v6
- Implement mbus_code filtering for format enumeration
---
 drivers/media/platform/rcar-vin/rcar-v4l2.c | 40 ++++++++++++---------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
index 5151a3cd8a6e6754..f421e25848756c97 100644
--- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
+++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
@@ -343,6 +343,29 @@ static int rvin_enum_fmt_vid_cap(struct file *file, void *priv,
 	unsigned int i;
 	int matched;
 
+	/*
+	 * If mbus_code is set only enumerate supported pixel formats for that
+	 * bus code. Converting from YCbCr to RGB and RGB to YCbCr is possible
+	 * with VIN, so all supported YCbCr and RGB media bus codes can produce
+	 * all of the related pixel formats. If mbus_code is not set enumerate
+	 * all possible pixelformats.
+	 *
+	 * TODO: Once raw capture formats are added to the driver this needs
+	 * to be extended so raw media bus codes only result in raw pixel
+	 * formats.
+	 */
+	switch (f->mbus_code) {
+	case 0:
+	case MEDIA_BUS_FMT_YUYV8_1X16:
+	case MEDIA_BUS_FMT_UYVY8_1X16:
+	case MEDIA_BUS_FMT_UYVY8_2X8:
+	case MEDIA_BUS_FMT_UYVY10_2X10:
+	case MEDIA_BUS_FMT_RGB888_1X24:
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	matched = -1;
 	for (i = 0; i < ARRAY_SIZE(rvin_formats); i++) {
 		if (rvin_format_from_pixel(vin, rvin_formats[i].fourcc))
@@ -767,18 +790,6 @@ static int rvin_mc_s_fmt_vid_cap(struct file *file, void *priv,
 	return 0;
 }
 
-static int rvin_mc_enum_input(struct file *file, void *priv,
-			      struct v4l2_input *i)
-{
-	if (i->index != 0)
-		return -EINVAL;
-
-	i->type = V4L2_INPUT_TYPE_CAMERA;
-	strscpy(i->name, "Camera", sizeof(i->name));
-
-	return 0;
-}
-
 static const struct v4l2_ioctl_ops rvin_mc_ioctl_ops = {
 	.vidioc_querycap		= rvin_querycap,
 	.vidioc_try_fmt_vid_cap		= rvin_mc_try_fmt_vid_cap,
@@ -786,10 +797,6 @@ static const struct v4l2_ioctl_ops rvin_mc_ioctl_ops = {
 	.vidioc_s_fmt_vid_cap		= rvin_mc_s_fmt_vid_cap,
 	.vidioc_enum_fmt_vid_cap	= rvin_enum_fmt_vid_cap,
 
-	.vidioc_enum_input		= rvin_mc_enum_input,
-	.vidioc_g_input			= rvin_g_input,
-	.vidioc_s_input			= rvin_s_input,
-
 	.vidioc_reqbufs			= vb2_ioctl_reqbufs,
 	.vidioc_create_bufs		= vb2_ioctl_create_bufs,
 	.vidioc_querybuf		= vb2_ioctl_querybuf,
@@ -961,6 +968,7 @@ int rvin_v4l2_register(struct rvin_dev *vin)
 	vin->format.colorspace = RVIN_DEFAULT_COLORSPACE;
 
 	if (vin->info->use_mc) {
+		vdev->device_caps |= V4L2_CAP_IO_MC;
 		vdev->ioctl_ops = &rvin_mc_ioctl_ops;
 	} else {
 		vdev->ioctl_ops = &rvin_ioctl_ops;
-- 
2.26.0

[PATCH v7 5/6] staging/intel-ipu3: Make use of V4L2_CAP_IO_MC

[Niklas Söderlund]

Set the V4L2_CAP_IO_MC capability flag and remove the driver specific
vidioc_enum_{input,output}, vidioc_g_{input,output} and
vidioc_s_{input,output} callbacks.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v5:

- Implement mbus_code filtering for format enumeration
---
 drivers/staging/media/ipu3/ipu3-v4l2.c | 64 +++-----------------------
 1 file changed, 7 insertions(+), 57 deletions(-)

diff --git a/drivers/staging/media/ipu3/ipu3-v4l2.c b/drivers/staging/media/ipu3/ipu3-v4l2.c
index 09c8ede1457cad96..6047b4c55d86c954 100644
--- a/drivers/staging/media/ipu3/ipu3-v4l2.c
+++ b/drivers/staging/media/ipu3/ipu3-v4l2.c
@@ -597,6 +597,9 @@ static int enum_fmts(struct v4l2_fmtdesc *f, u32 type)
 {
 	unsigned int i, j;
 
+	if (f->mbus_code != 0 && f->mbus_code != MEDIA_BUS_FMT_FIXED)
+		return -EINVAL;
+
 	for (i = j = 0; i < ARRAY_SIZE(formats); ++i) {
 		if (formats[i].type == type) {
 			if (j == f->index)
@@ -826,6 +829,9 @@ static int imgu_meta_enum_format(struct file *file, void *fh,
 	if (fmt->index > 0 || fmt->type != node->vbq.type)
 		return -EINVAL;
 
+	if (fmt->mbus_code != 0 && fmt->mbus_code != MEDIA_BUS_FMT_FIXED)
+		return -EINVAL;
+
 	strscpy(fmt->description, meta_fmts[i].name, sizeof(fmt->description));
 	fmt->pixelformat = meta_fmts[i].fourcc;
 
@@ -845,54 +851,6 @@ static int imgu_vidioc_g_meta_fmt(struct file *file, void *fh,
 	return 0;
 }
 
-static int imgu_vidioc_enum_input(struct file *file, void *fh,
-				  struct v4l2_input *input)
-{
-	if (input->index > 0)
-		return -EINVAL;
-	strscpy(input->name, "camera", sizeof(input->name));
-	input->type = V4L2_INPUT_TYPE_CAMERA;
-
-	return 0;
-}
-
-static int imgu_vidioc_g_input(struct file *file, void *fh, unsigned int *input)
-{
-	*input = 0;
-
-	return 0;
-}
-
-static int imgu_vidioc_s_input(struct file *file, void *fh, unsigned int input)
-{
-	return input == 0 ? 0 : -EINVAL;
-}
-
-static int imgu_vidioc_enum_output(struct file *file, void *fh,
-				   struct v4l2_output *output)
-{
-	if (output->index > 0)
-		return -EINVAL;
-	strscpy(output->name, "camera", sizeof(output->name));
-	output->type = V4L2_INPUT_TYPE_CAMERA;
-
-	return 0;
-}
-
-static int imgu_vidioc_g_output(struct file *file, void *fh,
-				unsigned int *output)
-{
-	*output = 0;
-
-	return 0;
-}
-
-static int imgu_vidioc_s_output(struct file *file, void *fh,
-				unsigned int output)
-{
-	return output == 0 ? 0 : -EINVAL;
-}
-
 /******************** function pointers ********************/
 
 static struct v4l2_subdev_internal_ops imgu_subdev_internal_ops = {
@@ -965,14 +923,6 @@ static const struct v4l2_ioctl_ops imgu_v4l2_ioctl_ops = {
 	.vidioc_s_fmt_vid_out_mplane = imgu_vidioc_s_fmt,
 	.vidioc_try_fmt_vid_out_mplane = imgu_vidioc_try_fmt,
 
-	.vidioc_enum_output = imgu_vidioc_enum_output,
-	.vidioc_g_output = imgu_vidioc_g_output,
-	.vidioc_s_output = imgu_vidioc_s_output,
-
-	.vidioc_enum_input = imgu_vidioc_enum_input,
-	.vidioc_g_input = imgu_vidioc_g_input,
-	.vidioc_s_input = imgu_vidioc_s_input,
-
 	/* buffer queue management */
 	.vidioc_reqbufs = vb2_ioctl_reqbufs,
 	.vidioc_create_bufs = vb2_ioctl_create_bufs,
@@ -1086,7 +1036,7 @@ static void imgu_node_to_v4l2(u32 node, struct video_device *vdev,
 		vdev->ioctl_ops = &imgu_v4l2_ioctl_ops;
 	}
 
-	vdev->device_caps = V4L2_CAP_STREAMING | cap;
+	vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_IO_MC | cap;
 }
 
 static int imgu_v4l2_subdev_register(struct imgu_device *imgu,
-- 
2.26.0

[PATCH v7 6/6] vimc: Make use of V4L2_CAP_IO_MC

[Niklas Söderlund]

Set the V4L2_CAP_IO_MC capability flag to report this vimc
inputs/outputs are controlled by the media graph.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
Changes since v5:

- Wrap line longer than 80 characters
- Implement mbus_code filtering for format enumeration
---
 drivers/media/platform/vimc/vimc-capture.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/vimc/vimc-capture.c b/drivers/media/platform/vimc/vimc-capture.c
index 747ea9cc1bd7cb12..dbc827fd1b9baebb 100644
--- a/drivers/media/platform/vimc/vimc-capture.c
+++ b/drivers/media/platform/vimc/vimc-capture.c
@@ -149,7 +149,12 @@ static int vimc_cap_s_fmt_vid_cap(struct file *file, void *priv,
 static int vimc_cap_enum_fmt_vid_cap(struct file *file, void *priv,
 				     struct v4l2_fmtdesc *f)
 {
-	const struct vimc_pix_map *vpix = vimc_pix_map_by_index(f->index);
+	const struct vimc_pix_map *vpix;
+
+	if (f->mbus_code)
+		vpix = vimc_pix_map_by_code(f->mbus_code);
+	else
+		vpix = vimc_pix_map_by_index(f->index);
 
 	if (!vpix)
 		return -EINVAL;
@@ -450,7 +455,8 @@ struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
 
 	/* Initialize the video_device struct */
 	vdev = &vcap->vdev;
-	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING
+			  | V4L2_CAP_IO_MC;
 	vdev->entity.ops = &vimc_cap_mops;
 	vdev->release = video_device_release_empty;
 	vdev->fops = &vimc_cap_fops;
-- 
2.26.0

Re: [PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Laurent Pinchart]

Hi Niklas,

On Mon, Apr 13, 2020 at 10:23:48PM +0200, Niklas Söderlund wrote:
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
> node. For MC-centric devices, its behaviour has always been ill-defined,
> with drivers implementing one of the following behaviours:
> 
> - No support for VIDIOC_ENUM_FMT at all
> - Enumerating all formats supported by the video node, regardless of the
>   configuration of the pipeline
> - Enumerating formats supported by the video node for the active
>   configuration of the connected subdevice
> 
> The first behaviour is obviously useless for applications. The second
> behaviour provides the most information, but doesn't offer a way to find
> what formats are compatible with a given pipeline configuration. The
> third behaviour fixes that, but with the drawback that applications
> can't enumerate all supported formats anymore, and have to modify the
> active configuration of the pipeline to enumerate formats.
> 
> The situation is messy as none of the implemented behaviours are ideal,
> and userspace can't predict what will happen as the behaviour is
> driver-specific.
> 
> To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
> enumerating pixel formats for a given media bus code. The media bus code
> is passed through the v4l2_fmtdesc structure in a new mbus_code field
> (repurposed from the reserved fields). With this capability in place,
> applications can enumerate pixel formats for a given media bus code
> without modifying the active configuration of the device.
> 
> The current behaviour of the ioctl is preserved when the new mbus_code
> field is set to 0, ensuring compatibility with existing userspace. The
> API extension is documented as mandatory for MC-centric devices (as
> advertised through the V4L2_CAP_IO_MC capability), allowing applications
> and compliance tools to easily determine the availability of the
> VIDIOC_ENUM_FMT extension.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Should this carry a tag from you ? :-)

> ---
>  .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
>  drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
>  include/uapi/linux/videodev2.h                  |  3 ++-
>  3 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> index 8ca6ab701e4ab99c..82792d8e910b2313 100644
> --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
>  formats in preference order, where preferred formats are returned before
>  (that is, with lower ``index`` value) less-preferred formats.
>  
> -.. note::
> +If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
> +:ref:`device-capabilities <capability>`, applications shall initialize the
> +``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
> +by the device. The enumerated formats may depend on the active input or output
> +of the device.
>  
> -   After switching input or output the list of enumerated image
> -   formats may be different.
> +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
> +<capability>`, applications may initialize the ``mbus_code`` to a valid
> +:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
> +is not zero, drivers shall restrict enumeration to only the image formats that
> +can produce (for video output devices) or be produced from (for video capture
> +devices) that media bus code. Regardless of the value of the ``mbus_code``
> +field, the enumerated image formats shall not depend on the active
> +configuration of the video device or device pipeline. Enumeration shall
> +otherwise operate as previously described.
>  
>  
>  .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index afd1f427df557f71..3e7b99fa415222c6 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
>  {
>  	const struct v4l2_fmtdesc *p = arg;
>  
> -	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
> +	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
>  		p->index, prt_names(p->type, v4l2_type_names),
>  		p->flags, (p->pixelformat & 0xff),
>  		(p->pixelformat >>  8) & 0xff,
>  		(p->pixelformat >> 16) & 0xff,
>  		(p->pixelformat >> 24) & 0xff,
> +		p->mbus_code,
>  		(int)sizeof(p->description), p->description);
>  }
>  
> @@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>  	struct video_device *vdev = video_devdata(file);
>  	struct v4l2_fmtdesc *p = arg;
>  	int ret = check_fmt(file, p->type);
> +	u32 mbus_code;
>  	u32 cap_mask;
>  
>  	if (ret)
>  		return ret;
>  	ret = -EINVAL;
>  
> +	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
> +		return -EINVAL;
> +
> +	mbus_code = p->mbus_code;
> +	CLEAR_AFTER_FIELD(p, type);
> +	p->mbus_code = mbus_code;
> +
>  	switch (p->type) {
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> @@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
>  
>  static const struct v4l2_ioctl_info v4l2_ioctls[] = {
>  	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
> -	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> +	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
>  	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
>  	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
>  	__u32               flags;
>  	__u8		    description[32];   /* Description string */
>  	__u32		    pixelformat;       /* Format fourcc      */
> -	__u32		    reserved[4];
> +	__u32		    mbus_code;		/* Media bus code    */
> +	__u32		    reserved[3];
>  };
>  
>  #define V4L2_FMT_FLAG_COMPRESSED		0x0001

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Niklas Söderlund]

Hi Laurent,

On 2020-04-14 12:40:49 +0300, Laurent Pinchart wrote:
> Hi Niklas,
> 
> On Mon, Apr 13, 2020 at 10:23:48PM +0200, Niklas Söderlund wrote:
> > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
> > node. For MC-centric devices, its behaviour has always been ill-defined,
> > with drivers implementing one of the following behaviours:
> > 
> > - No support for VIDIOC_ENUM_FMT at all
> > - Enumerating all formats supported by the video node, regardless of the
> >   configuration of the pipeline
> > - Enumerating formats supported by the video node for the active
> >   configuration of the connected subdevice
> > 
> > The first behaviour is obviously useless for applications. The second
> > behaviour provides the most information, but doesn't offer a way to find
> > what formats are compatible with a given pipeline configuration. The
> > third behaviour fixes that, but with the drawback that applications
> > can't enumerate all supported formats anymore, and have to modify the
> > active configuration of the pipeline to enumerate formats.
> > 
> > The situation is messy as none of the implemented behaviours are ideal,
> > and userspace can't predict what will happen as the behaviour is
> > driver-specific.
> > 
> > To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
> > enumerating pixel formats for a given media bus code. The media bus code
> > is passed through the v4l2_fmtdesc structure in a new mbus_code field
> > (repurposed from the reserved fields). With this capability in place,
> > applications can enumerate pixel formats for a given media bus code
> > without modifying the active configuration of the device.
> > 
> > The current behaviour of the ioctl is preserved when the new mbus_code
> > field is set to 0, ensuring compatibility with existing userspace. The
> > API extension is documented as mandatory for MC-centric devices (as
> > advertised through the V4L2_CAP_IO_MC capability), allowing applications
> > and compliance tools to easily determine the availability of the
> > VIDIOC_ENUM_FMT extension.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Should this carry a tag from you ? :-)

Yes :-)

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> 
> > ---
> >  .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
> >  drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
> >  include/uapi/linux/videodev2.h                  |  3 ++-
> >  3 files changed, 27 insertions(+), 6 deletions(-)
> > 
> > diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > index 8ca6ab701e4ab99c..82792d8e910b2313 100644
> > --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
> >  formats in preference order, where preferred formats are returned before
> >  (that is, with lower ``index`` value) less-preferred formats.
> >  
> > -.. note::
> > +If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
> > +:ref:`device-capabilities <capability>`, applications shall initialize the
> > +``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
> > +by the device. The enumerated formats may depend on the active input or output
> > +of the device.
> >  
> > -   After switching input or output the list of enumerated image
> > -   formats may be different.
> > +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
> > +<capability>`, applications may initialize the ``mbus_code`` to a valid
> > +:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
> > +is not zero, drivers shall restrict enumeration to only the image formats that
> > +can produce (for video output devices) or be produced from (for video capture
> > +devices) that media bus code. Regardless of the value of the ``mbus_code``
> > +field, the enumerated image formats shall not depend on the active
> > +configuration of the video device or device pipeline. Enumeration shall
> > +otherwise operate as previously described.
> >  
> >  
> >  .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index afd1f427df557f71..3e7b99fa415222c6 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
> >  {
> >  	const struct v4l2_fmtdesc *p = arg;
> >  
> > -	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
> > +	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
> >  		p->index, prt_names(p->type, v4l2_type_names),
> >  		p->flags, (p->pixelformat & 0xff),
> >  		(p->pixelformat >>  8) & 0xff,
> >  		(p->pixelformat >> 16) & 0xff,
> >  		(p->pixelformat >> 24) & 0xff,
> > +		p->mbus_code,
> >  		(int)sizeof(p->description), p->description);
> >  }
> >  
> > @@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
> >  	struct video_device *vdev = video_devdata(file);
> >  	struct v4l2_fmtdesc *p = arg;
> >  	int ret = check_fmt(file, p->type);
> > +	u32 mbus_code;
> >  	u32 cap_mask;
> >  
> >  	if (ret)
> >  		return ret;
> >  	ret = -EINVAL;
> >  
> > +	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
> > +		return -EINVAL;
> > +
> > +	mbus_code = p->mbus_code;
> > +	CLEAR_AFTER_FIELD(p, type);
> > +	p->mbus_code = mbus_code;
> > +
> >  	switch (p->type) {
> >  	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
> >  	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> > @@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
> >  
> >  static const struct v4l2_ioctl_info v4l2_ioctls[] = {
> >  	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
> > -	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> > +	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
> >  	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
> >  	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
> >  	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
> >  	__u32               flags;
> >  	__u8		    description[32];   /* Description string */
> >  	__u32		    pixelformat;       /* Format fourcc      */
> > -	__u32		    reserved[4];
> > +	__u32		    mbus_code;		/* Media bus code    */
> > +	__u32		    reserved[3];
> >  };
> >  
> >  #define V4L2_FMT_FLAG_COMPRESSED		0x0001
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Regards,
Niklas Söderlund

Re: [PATCH v7 1/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[Hans Verkuil]

Hi Niklas,

On 13/04/2020 22:23, Niklas Söderlund wrote:
> 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@xs4all.nl>
> Signed-off-by: Helen Koike <helen.koike@collabora.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  .../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..3048811450182185 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 && !is_meta) {

I noticed the addition of !is_meta. Digging into the history I saw that it was
a request from Sakari in the v4 review. I must have missed that since I disagree
with that change.

If IO_MC is set, then this applies to video/meta/vbi. After all, vbi is just a
special kind of metadata (and we'd use a metadata device node if we would design
that today), so it makes no sense to do something different for metadata.

Another issue here is that video devices can be for video, for metadata, or for
both. So if is_io_mc is true, then you would get different behavior depending
on the type of video device: if it is just video, then it supports the INPUT
ioctls, if it supports metadata as well, then it doesn't.

I would just keep this as it was originally:

			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 && !is_meta) {

Same here.

The remainder of the series looks good (except that an additional cx18 patch is
needed as Andrey pointed out on irc).

Regards,

	Hans

> +				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 b2ef8e60ea7da19d..afd1f427df557f71 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) {
> +		*(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) {
> +		*(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  *(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  *(int *)arg ? -EINVAL : 0;
> +
>  	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;
> +		return 0;
> +	}
> +
>  	return ops->vidioc_enum_output(file, fh, p);
>  }
>  
> @@ -2683,10 +2734,8 @@ DEFINE_V4L_STUB_FUNC(expbuf)
>  DEFINE_V4L_STUB_FUNC(g_std)
>  DEFINE_V4L_STUB_FUNC(g_audio)
>  DEFINE_V4L_STUB_FUNC(s_audio)
> -DEFINE_V4L_STUB_FUNC(g_input)
>  DEFINE_V4L_STUB_FUNC(g_edid)
>  DEFINE_V4L_STUB_FUNC(s_edid)
> -DEFINE_V4L_STUB_FUNC(g_output)
>  DEFINE_V4L_STUB_FUNC(g_audout)
>  DEFINE_V4L_STUB_FUNC(s_audout)
>  DEFINE_V4L_STUB_FUNC(g_jpegcomp)
> @@ -2735,11 +2784,11 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = {
>  	IOCTL_INFO(VIDIOC_S_AUDIO, v4l_stub_s_audio, v4l_print_audio, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)),
>  	IOCTL_INFO(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)),
> -	IOCTL_INFO(VIDIOC_G_INPUT, v4l_stub_g_input, v4l_print_u32, 0),
> +	IOCTL_INFO(VIDIOC_G_INPUT, v4l_g_input, v4l_print_u32, 0),
>  	IOCTL_INFO(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_G_EDID, v4l_stub_g_edid, v4l_print_edid, INFO_FL_ALWAYS_COPY),
>  	IOCTL_INFO(VIDIOC_S_EDID, v4l_stub_s_edid, v4l_print_edid, INFO_FL_PRIO | INFO_FL_ALWAYS_COPY),
> -	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_stub_g_output, v4l_print_u32, 0),
> +	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_g_output, v4l_print_u32, 0),
>  	IOCTL_INFO(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)),
>  	IOCTL_INFO(VIDIOC_G_AUDOUT, v4l_stub_g_audout, v4l_print_audioout, 0),
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 9817b7e2c968fd04..b18f3f7cde31c2e4 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -487,6 +487,8 @@ struct v4l2_capability {
>  
>  #define V4L2_CAP_TOUCH                  0x10000000  /* Is a touch device */
>  
> +#define V4L2_CAP_IO_MC			0x20000000  /* Is input/output controlled by the media controller */
> +
>  #define V4L2_CAP_DEVICE_CAPS            0x80000000  /* sets device capabilities field */
>  
>  /*
> 

Re: [PATCH v7 1/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[Laurent Pinchart]

Hi Hans,

On Tue, Apr 14, 2020 at 01:42:46PM +0200, Hans Verkuil wrote:
> On 13/04/2020 22:23, Niklas Söderlund wrote:
> > 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@xs4all.nl>
> > Signed-off-by: Helen Koike <helen.koike@collabora.com>
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> > Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > ---
> >  .../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..3048811450182185 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 && !is_meta) {
> 
> I noticed the addition of !is_meta. Digging into the history I saw that it was
> a request from Sakari in the v4 review. I must have missed that since I disagree
> with that change.
> 
> If IO_MC is set, then this applies to video/meta/vbi. After all, vbi is just a
> special kind of metadata (and we'd use a metadata device node if we would design
> that today), so it makes no sense to do something different for metadata.
> 
> Another issue here is that video devices can be for video, for metadata, or for
> both. So if is_io_mc is true, then you would get different behavior depending
> on the type of video device: if it is just video, then it supports the INPUT
> ioctls, if it supports metadata as well, then it doesn't.

As expressed before, I think we really should drop VIDIOC_ENUMINPUT,
VIDIOC_G_INPUT and VIDIOC_S_INPUT for devices that have V4L2_CAP_IO_MC
set. They can't be supported by generic video node-centric applications
that expect those ioctls to be supported in any case, so it makes little
sense. With V4L2_CAP_IO_MC added, the v4l2-compliance tool can ignore
those ioctls (or, even better, report an error if they're implemented).

> I would just keep this as it was originally:
> 
> 			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 && !is_meta) {
> 
> Same here.
> 
> The remainder of the series looks good (except that an additional cx18 patch is
> needed as Andrey pointed out on irc).
> 
> > +				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 b2ef8e60ea7da19d..afd1f427df557f71 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) {
> > +		*(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) {
> > +		*(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  *(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  *(int *)arg ? -EINVAL : 0;
> > +
> >  	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;
> > +		return 0;
> > +	}
> > +
> >  	return ops->vidioc_enum_output(file, fh, p);
> >  }
> >  
> > @@ -2683,10 +2734,8 @@ DEFINE_V4L_STUB_FUNC(expbuf)
> >  DEFINE_V4L_STUB_FUNC(g_std)
> >  DEFINE_V4L_STUB_FUNC(g_audio)
> >  DEFINE_V4L_STUB_FUNC(s_audio)
> > -DEFINE_V4L_STUB_FUNC(g_input)
> >  DEFINE_V4L_STUB_FUNC(g_edid)
> >  DEFINE_V4L_STUB_FUNC(s_edid)
> > -DEFINE_V4L_STUB_FUNC(g_output)
> >  DEFINE_V4L_STUB_FUNC(g_audout)
> >  DEFINE_V4L_STUB_FUNC(s_audout)
> >  DEFINE_V4L_STUB_FUNC(g_jpegcomp)
> > @@ -2735,11 +2784,11 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = {
> >  	IOCTL_INFO(VIDIOC_S_AUDIO, v4l_stub_s_audio, v4l_print_audio, INFO_FL_PRIO),
> >  	IOCTL_INFO(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)),
> >  	IOCTL_INFO(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)),
> > -	IOCTL_INFO(VIDIOC_G_INPUT, v4l_stub_g_input, v4l_print_u32, 0),
> > +	IOCTL_INFO(VIDIOC_G_INPUT, v4l_g_input, v4l_print_u32, 0),
> >  	IOCTL_INFO(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO),
> >  	IOCTL_INFO(VIDIOC_G_EDID, v4l_stub_g_edid, v4l_print_edid, INFO_FL_ALWAYS_COPY),
> >  	IOCTL_INFO(VIDIOC_S_EDID, v4l_stub_s_edid, v4l_print_edid, INFO_FL_PRIO | INFO_FL_ALWAYS_COPY),
> > -	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_stub_g_output, v4l_print_u32, 0),
> > +	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_g_output, v4l_print_u32, 0),
> >  	IOCTL_INFO(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO),
> >  	IOCTL_INFO(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)),
> >  	IOCTL_INFO(VIDIOC_G_AUDOUT, v4l_stub_g_audout, v4l_print_audioout, 0),
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index 9817b7e2c968fd04..b18f3f7cde31c2e4 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -487,6 +487,8 @@ struct v4l2_capability {
> >  
> >  #define V4L2_CAP_TOUCH                  0x10000000  /* Is a touch device */
> >  
> > +#define V4L2_CAP_IO_MC			0x20000000  /* Is input/output controlled by the media controller */
> > +
> >  #define V4L2_CAP_DEVICE_CAPS            0x80000000  /* sets device capabilities field */
> >  
> >  /*

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 1/6] v4l2-dev/ioctl: Add V4L2_CAP_IO_MC

[Hans Verkuil]

On 15/04/2020 01:36, Laurent Pinchart wrote:
> Hi Hans,
> 
> On Tue, Apr 14, 2020 at 01:42:46PM +0200, Hans Verkuil wrote:
>> On 13/04/2020 22:23, Niklas Söderlund wrote:
>>> 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@xs4all.nl>
>>> Signed-off-by: Helen Koike <helen.koike@collabora.com>
>>> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
>>> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
>>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>> ---
>>>  .../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..3048811450182185 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 && !is_meta) {
>>
>> I noticed the addition of !is_meta. Digging into the history I saw that it was
>> a request from Sakari in the v4 review. I must have missed that since I disagree
>> with that change.
>>
>> If IO_MC is set, then this applies to video/meta/vbi. After all, vbi is just a
>> special kind of metadata (and we'd use a metadata device node if we would design
>> that today), so it makes no sense to do something different for metadata.
>>
>> Another issue here is that video devices can be for video, for metadata, or for
>> both. So if is_io_mc is true, then you would get different behavior depending
>> on the type of video device: if it is just video, then it supports the INPUT
>> ioctls, if it supports metadata as well, then it doesn't.
> 
> As expressed before, I think we really should drop VIDIOC_ENUMINPUT,
> VIDIOC_G_INPUT and VIDIOC_S_INPUT for devices that have V4L2_CAP_IO_MC
> set. They can't be supported by generic video node-centric applications
> that expect those ioctls to be supported in any case, so it makes little
> sense. With V4L2_CAP_IO_MC added, the v4l2-compliance tool can ignore
> those ioctls (or, even better, report an error if they're implemented).

I know your opinion on this, and I disagree. All non-MC video capture or output
devices support the input/output ioctls, and to suddenly make an exception is
not a good idea IMHO. On the other hand, I do agree that it makes no sense that
MC drivers would have to implement dummy ioctls. So having the core do this is,
I think, a good compromise.

In general I believe we should avoid introducing exceptions in the public API
unless there is no alternative. In this case there is a workable alternative
(dummy ioctls provided by the core).

Regards,

	Hans

> 
>> I would just keep this as it was originally:
>>
>> 			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 && !is_meta) {
>>
>> Same here.
>>
>> The remainder of the series looks good (except that an additional cx18 patch is
>> needed as Andrey pointed out on irc).
>>
>>> +				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 b2ef8e60ea7da19d..afd1f427df557f71 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) {
>>> +		*(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) {
>>> +		*(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  *(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  *(int *)arg ? -EINVAL : 0;
>>> +
>>>  	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;
>>> +		return 0;
>>> +	}
>>> +
>>>  	return ops->vidioc_enum_output(file, fh, p);
>>>  }
>>>  
>>> @@ -2683,10 +2734,8 @@ DEFINE_V4L_STUB_FUNC(expbuf)
>>>  DEFINE_V4L_STUB_FUNC(g_std)
>>>  DEFINE_V4L_STUB_FUNC(g_audio)
>>>  DEFINE_V4L_STUB_FUNC(s_audio)
>>> -DEFINE_V4L_STUB_FUNC(g_input)
>>>  DEFINE_V4L_STUB_FUNC(g_edid)
>>>  DEFINE_V4L_STUB_FUNC(s_edid)
>>> -DEFINE_V4L_STUB_FUNC(g_output)
>>>  DEFINE_V4L_STUB_FUNC(g_audout)
>>>  DEFINE_V4L_STUB_FUNC(s_audout)
>>>  DEFINE_V4L_STUB_FUNC(g_jpegcomp)
>>> @@ -2735,11 +2784,11 @@ static const struct v4l2_ioctl_info v4l2_ioctls[] = {
>>>  	IOCTL_INFO(VIDIOC_S_AUDIO, v4l_stub_s_audio, v4l_print_audio, INFO_FL_PRIO),
>>>  	IOCTL_INFO(VIDIOC_QUERYCTRL, v4l_queryctrl, v4l_print_queryctrl, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_queryctrl, id)),
>>>  	IOCTL_INFO(VIDIOC_QUERYMENU, v4l_querymenu, v4l_print_querymenu, INFO_FL_CTRL | INFO_FL_CLEAR(v4l2_querymenu, index)),
>>> -	IOCTL_INFO(VIDIOC_G_INPUT, v4l_stub_g_input, v4l_print_u32, 0),
>>> +	IOCTL_INFO(VIDIOC_G_INPUT, v4l_g_input, v4l_print_u32, 0),
>>>  	IOCTL_INFO(VIDIOC_S_INPUT, v4l_s_input, v4l_print_u32, INFO_FL_PRIO),
>>>  	IOCTL_INFO(VIDIOC_G_EDID, v4l_stub_g_edid, v4l_print_edid, INFO_FL_ALWAYS_COPY),
>>>  	IOCTL_INFO(VIDIOC_S_EDID, v4l_stub_s_edid, v4l_print_edid, INFO_FL_PRIO | INFO_FL_ALWAYS_COPY),
>>> -	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_stub_g_output, v4l_print_u32, 0),
>>> +	IOCTL_INFO(VIDIOC_G_OUTPUT, v4l_g_output, v4l_print_u32, 0),
>>>  	IOCTL_INFO(VIDIOC_S_OUTPUT, v4l_s_output, v4l_print_u32, INFO_FL_PRIO),
>>>  	IOCTL_INFO(VIDIOC_ENUMOUTPUT, v4l_enumoutput, v4l_print_enumoutput, INFO_FL_CLEAR(v4l2_output, index)),
>>>  	IOCTL_INFO(VIDIOC_G_AUDOUT, v4l_stub_g_audout, v4l_print_audioout, 0),
>>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>>> index 9817b7e2c968fd04..b18f3f7cde31c2e4 100644
>>> --- a/include/uapi/linux/videodev2.h
>>> +++ b/include/uapi/linux/videodev2.h
>>> @@ -487,6 +487,8 @@ struct v4l2_capability {
>>>  
>>>  #define V4L2_CAP_TOUCH                  0x10000000  /* Is a touch device */
>>>  
>>> +#define V4L2_CAP_IO_MC			0x20000000  /* Is input/output controlled by the media controller */
>>> +
>>>  #define V4L2_CAP_DEVICE_CAPS            0x80000000  /* sets device capabilities field */
>>>  
>>>  /*
> 

Re: [PATCH v7 6/6] vimc: Make use of V4L2_CAP_IO_MC

[Dafna Hirschfeld]

On 13.04.20 22:23, Niklas Söderlund wrote:
> Set the V4L2_CAP_IO_MC capability flag to report this vimc
> inputs/outputs are controlled by the media graph.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
> Changes since v5:
> 
> - Wrap line longer than 80 characters
> - Implement mbus_code filtering for format enumeration
> ---
>   drivers/media/platform/vimc/vimc-capture.c | 10 ++++++++--
>   1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/vimc/vimc-capture.c b/drivers/media/platform/vimc/vimc-capture.c
> index 747ea9cc1bd7cb12..dbc827fd1b9baebb 100644
> --- a/drivers/media/platform/vimc/vimc-capture.c
> +++ b/drivers/media/platform/vimc/vimc-capture.c
> @@ -149,7 +149,12 @@ static int vimc_cap_s_fmt_vid_cap(struct file *file, void *priv,
>   static int vimc_cap_enum_fmt_vid_cap(struct file *file, void *priv,
>   				     struct v4l2_fmtdesc *f)
>   {
> -	const struct vimc_pix_map *vpix = vimc_pix_map_by_index(f->index);
> +	const struct vimc_pix_map *vpix;
> +
> +	if (f->mbus_code)
> +		vpix = vimc_pix_map_by_code(f->mbus_code);
Hi, if I understand correctly, the f->index should still tell us we should return the i'th format
for the given mbus_code, right? if yes then since vimc support only one pixelformat for each mbus code
there should be a code added here:
if (f->index > 0)
	return -EINVAL;

Thanks,
Dafna

> +	else
> +		vpix = vimc_pix_map_by_index(f->index);
>   
>   	if (!vpix)
>   		return -EINVAL;
> @@ -450,7 +455,8 @@ struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
>   
>   	/* Initialize the video_device struct */
>   	vdev = &vcap->vdev;
> -	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
> +	vdev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING
> +			  | V4L2_CAP_IO_MC;
>   	vdev->entity.ops = &vimc_cap_mops;
>   	vdev->release = video_device_release_empty;
>   	vdev->fops = &vimc_cap_fops;
> 

Re: [PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Sakari Ailus]

Hejssan,

On Mon, Apr 13, 2020 at 10:23:48PM +0200, Niklas Söderlund wrote:
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
> node. For MC-centric devices, its behaviour has always been ill-defined,
> with drivers implementing one of the following behaviours:
> 
> - No support for VIDIOC_ENUM_FMT at all
> - Enumerating all formats supported by the video node, regardless of the
>   configuration of the pipeline
> - Enumerating formats supported by the video node for the active
>   configuration of the connected subdevice
> 
> The first behaviour is obviously useless for applications. The second
> behaviour provides the most information, but doesn't offer a way to find
> what formats are compatible with a given pipeline configuration. The
> third behaviour fixes that, but with the drawback that applications
> can't enumerate all supported formats anymore, and have to modify the
> active configuration of the pipeline to enumerate formats.
> 
> The situation is messy as none of the implemented behaviours are ideal,
> and userspace can't predict what will happen as the behaviour is
> driver-specific.
> 
> To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
> enumerating pixel formats for a given media bus code. The media bus code
> is passed through the v4l2_fmtdesc structure in a new mbus_code field
> (repurposed from the reserved fields). With this capability in place,
> applications can enumerate pixel formats for a given media bus code
> without modifying the active configuration of the device.
> 
> The current behaviour of the ioctl is preserved when the new mbus_code
> field is set to 0, ensuring compatibility with existing userspace. The
> API extension is documented as mandatory for MC-centric devices (as
> advertised through the V4L2_CAP_IO_MC capability), allowing applications
> and compliance tools to easily determine the availability of the
> VIDIOC_ENUM_FMT extension.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Din egen Sob linjen saknas här.

> ---
>  .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
>  drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
>  include/uapi/linux/videodev2.h                  |  3 ++-
>  3 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> index 8ca6ab701e4ab99c..82792d8e910b2313 100644
> --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
>  formats in preference order, where preferred formats are returned before
>  (that is, with lower ``index`` value) less-preferred formats.
>  
> -.. note::
> +If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
> +:ref:`device-capabilities <capability>`, applications shall initialize the
> +``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
> +by the device. The enumerated formats may depend on the active input or output

s/ supported by the device//

> +of the device.

How about

	s/active input or output/current configuration/

Then,

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

>  
> -   After switching input or output the list of enumerated image
> -   formats may be different.
> +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
> +<capability>`, applications may initialize the ``mbus_code`` to a valid
> +:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
> +is not zero, drivers shall restrict enumeration to only the image formats that
> +can produce (for video output devices) or be produced from (for video capture
> +devices) that media bus code. Regardless of the value of the ``mbus_code``
> +field, the enumerated image formats shall not depend on the active
> +configuration of the video device or device pipeline. Enumeration shall
> +otherwise operate as previously described.
>  
>  
>  .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index afd1f427df557f71..3e7b99fa415222c6 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
>  {
>  	const struct v4l2_fmtdesc *p = arg;
>  
> -	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
> +	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
>  		p->index, prt_names(p->type, v4l2_type_names),
>  		p->flags, (p->pixelformat & 0xff),
>  		(p->pixelformat >>  8) & 0xff,
>  		(p->pixelformat >> 16) & 0xff,
>  		(p->pixelformat >> 24) & 0xff,
> +		p->mbus_code,
>  		(int)sizeof(p->description), p->description);
>  }
>  
> @@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>  	struct video_device *vdev = video_devdata(file);
>  	struct v4l2_fmtdesc *p = arg;
>  	int ret = check_fmt(file, p->type);
> +	u32 mbus_code;
>  	u32 cap_mask;
>  
>  	if (ret)
>  		return ret;
>  	ret = -EINVAL;
>  
> +	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
> +		return -EINVAL;
> +
> +	mbus_code = p->mbus_code;
> +	CLEAR_AFTER_FIELD(p, type);
> +	p->mbus_code = mbus_code;
> +
>  	switch (p->type) {
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> @@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
>  
>  static const struct v4l2_ioctl_info v4l2_ioctls[] = {
>  	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
> -	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> +	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
>  	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
>  	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
>  	__u32               flags;
>  	__u8		    description[32];   /* Description string */
>  	__u32		    pixelformat;       /* Format fourcc      */
> -	__u32		    reserved[4];
> +	__u32		    mbus_code;		/* Media bus code    */
> +	__u32		    reserved[3];
>  };
>  
>  #define V4L2_FMT_FLAG_COMPRESSED		0x0001
> -- 
> 2.26.0
> 

-- 
Med trevliga hälsningar,

Sakari Ailus

Re: [PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Laurent Pinchart]

Hi Sakari,

On Wed, Apr 15, 2020 at 05:31:49PM +0300, Sakari Ailus wrote:
> On Mon, Apr 13, 2020 at 10:23:48PM +0200, Niklas Söderlund wrote:
> > From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > 
> > The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
> > node. For MC-centric devices, its behaviour has always been ill-defined,
> > with drivers implementing one of the following behaviours:
> > 
> > - No support for VIDIOC_ENUM_FMT at all
> > - Enumerating all formats supported by the video node, regardless of the
> >   configuration of the pipeline
> > - Enumerating formats supported by the video node for the active
> >   configuration of the connected subdevice
> > 
> > The first behaviour is obviously useless for applications. The second
> > behaviour provides the most information, but doesn't offer a way to find
> > what formats are compatible with a given pipeline configuration. The
> > third behaviour fixes that, but with the drawback that applications
> > can't enumerate all supported formats anymore, and have to modify the
> > active configuration of the pipeline to enumerate formats.
> > 
> > The situation is messy as none of the implemented behaviours are ideal,
> > and userspace can't predict what will happen as the behaviour is
> > driver-specific.
> > 
> > To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
> > enumerating pixel formats for a given media bus code. The media bus code
> > is passed through the v4l2_fmtdesc structure in a new mbus_code field
> > (repurposed from the reserved fields). With this capability in place,
> > applications can enumerate pixel formats for a given media bus code
> > without modifying the active configuration of the device.
> > 
> > The current behaviour of the ioctl is preserved when the new mbus_code
> > field is set to 0, ensuring compatibility with existing userspace. The
> > API extension is documented as mandatory for MC-centric devices (as
> > advertised through the V4L2_CAP_IO_MC capability), allowing applications
> > and compliance tools to easily determine the availability of the
> > VIDIOC_ENUM_FMT extension.
> > 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> Din egen Sob linjen saknas här.
> 
> > ---
> >  .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
> >  drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
> >  include/uapi/linux/videodev2.h                  |  3 ++-
> >  3 files changed, 27 insertions(+), 6 deletions(-)
> > 
> > diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > index 8ca6ab701e4ab99c..82792d8e910b2313 100644
> > --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> > @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
> >  formats in preference order, where preferred formats are returned before
> >  (that is, with lower ``index`` value) less-preferred formats.
> >  
> > -.. note::
> > +If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
> > +:ref:`device-capabilities <capability>`, applications shall initialize the
> > +``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
> > +by the device. The enumerated formats may depend on the active input or output
> 
> s/ supported by the device//

OK.

> > +of the device.
> 
> How about
> 
> 	s/active input or output/current configuration/

I went for "active input or output" to match the current text that
states that the enumerated image formats may be different "after
switching input or output". I would like to avoid extending this to
cover any device configuration, as that's even more ill-defined (it
doesn't specify what device configuration may influence the formats, and
how).

> Then,
> 
> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> 
> > -   After switching input or output the list of enumerated image
> > -   formats may be different.
> > +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
> > +<capability>`, applications may initialize the ``mbus_code`` to a valid
> > +:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
> > +is not zero, drivers shall restrict enumeration to only the image formats that
> > +can produce (for video output devices) or be produced from (for video capture
> > +devices) that media bus code. Regardless of the value of the ``mbus_code``
> > +field, the enumerated image formats shall not depend on the active
> > +configuration of the video device or device pipeline. Enumeration shall
> > +otherwise operate as previously described.
> >  
> >  
> >  .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index afd1f427df557f71..3e7b99fa415222c6 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
> >  {
> >  	const struct v4l2_fmtdesc *p = arg;
> >  
> > -	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
> > +	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
> >  		p->index, prt_names(p->type, v4l2_type_names),
> >  		p->flags, (p->pixelformat & 0xff),
> >  		(p->pixelformat >>  8) & 0xff,
> >  		(p->pixelformat >> 16) & 0xff,
> >  		(p->pixelformat >> 24) & 0xff,
> > +		p->mbus_code,
> >  		(int)sizeof(p->description), p->description);
> >  }
> >  
> > @@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
> >  	struct video_device *vdev = video_devdata(file);
> >  	struct v4l2_fmtdesc *p = arg;
> >  	int ret = check_fmt(file, p->type);
> > +	u32 mbus_code;
> >  	u32 cap_mask;
> >  
> >  	if (ret)
> >  		return ret;
> >  	ret = -EINVAL;
> >  
> > +	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
> > +		return -EINVAL;
> > +
> > +	mbus_code = p->mbus_code;
> > +	CLEAR_AFTER_FIELD(p, type);
> > +	p->mbus_code = mbus_code;
> > +
> >  	switch (p->type) {
> >  	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
> >  	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> > @@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
> >  
> >  static const struct v4l2_ioctl_info v4l2_ioctls[] = {
> >  	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
> > -	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> > +	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
> >  	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
> >  	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
> >  	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
> >  	__u32               flags;
> >  	__u8		    description[32];   /* Description string */
> >  	__u32		    pixelformat;       /* Format fourcc      */
> > -	__u32		    reserved[4];
> > +	__u32		    mbus_code;		/* Media bus code    */
> > +	__u32		    reserved[3];
> >  };
> >  
> >  #define V4L2_FMT_FLAG_COMPRESSED		0x0001

-- 
Regards,

Laurent Pinchart

Re: [PATCH v7 2/6] ivtv-ioctl.c: Do not initialize the reserved field of struct v4l2_fmtdesc

[Hans Verkuil]

Hi Niklas,

On 13/04/2020 22:23, Niklas Söderlund wrote:
> One of the reserved fields are about to be used. Instead of updating the
> driver to only initialize three instead of four reserved fields remove
> the explicit assignment.  As if one field in a struct is assigned, the
> memory is zeroed and explicit assignment is redundant.
> 
> Reported-by: kbuild test robot <lkp@intel.com>
> Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

Can you replace this with this patch from Laurent when you post the v8?

https://patchwork.linuxtv.org/patch/62430/

I like that one better, and it fixes cx18 as well.

Regards,

	Hans

> ---
>  drivers/media/pci/ivtv/ivtv-ioctl.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/media/pci/ivtv/ivtv-ioctl.c b/drivers/media/pci/ivtv/ivtv-ioctl.c
> index 137853944e4619cb..8a45c50411c74831 100644
> --- a/drivers/media/pci/ivtv/ivtv-ioctl.c
> +++ b/drivers/media/pci/ivtv/ivtv-ioctl.c
> @@ -922,12 +922,10 @@ static int ivtv_enum_fmt_vid_cap(struct file *file, void *fh, struct v4l2_fmtdes
>  	static const struct v4l2_fmtdesc hm12 = {
>  		0, V4L2_BUF_TYPE_VIDEO_CAPTURE, 0,
>  		"HM12 (YUV 4:2:0)", V4L2_PIX_FMT_HM12,
> -		{ 0, 0, 0, 0 }
>  	};
>  	static const struct v4l2_fmtdesc mpeg = {
>  		0, V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FMT_FLAG_COMPRESSED,
>  		"MPEG", V4L2_PIX_FMT_MPEG,
> -		{ 0, 0, 0, 0 }
>  	};
>  	struct ivtv *itv = fh2id(fh)->itv;
>  	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
> @@ -948,12 +946,10 @@ static int ivtv_enum_fmt_vid_out(struct file *file, void *fh, struct v4l2_fmtdes
>  	static const struct v4l2_fmtdesc hm12 = {
>  		0, V4L2_BUF_TYPE_VIDEO_OUTPUT, 0,
>  		"HM12 (YUV 4:2:0)", V4L2_PIX_FMT_HM12,
> -		{ 0, 0, 0, 0 }
>  	};
>  	static const struct v4l2_fmtdesc mpeg = {
>  		0, V4L2_BUF_TYPE_VIDEO_OUTPUT, V4L2_FMT_FLAG_COMPRESSED,
>  		"MPEG", V4L2_PIX_FMT_MPEG,
> -		{ 0, 0, 0, 0 }
>  	};
>  	struct ivtv *itv = fh2id(fh)->itv;
>  	struct ivtv_stream *s = &itv->streams[fh2id(fh)->type];
> 

Re: [PATCH v7 3/6] media: v4l2: Extend VIDIOC_ENUM_FMT to support MC-centric devices

[Hans Verkuil]

On 13/04/2020 22:23, Niklas Söderlund wrote:
> From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> The VIDIOC_ENUM_FMT ioctl enumerates all formats supported by a video
> node. For MC-centric devices, its behaviour has always been ill-defined,
> with drivers implementing one of the following behaviours:
> 
> - No support for VIDIOC_ENUM_FMT at all
> - Enumerating all formats supported by the video node, regardless of the
>   configuration of the pipeline
> - Enumerating formats supported by the video node for the active
>   configuration of the connected subdevice
> 
> The first behaviour is obviously useless for applications. The second
> behaviour provides the most information, but doesn't offer a way to find
> what formats are compatible with a given pipeline configuration. The
> third behaviour fixes that, but with the drawback that applications
> can't enumerate all supported formats anymore, and have to modify the
> active configuration of the pipeline to enumerate formats.
> 
> The situation is messy as none of the implemented behaviours are ideal,
> and userspace can't predict what will happen as the behaviour is
> driver-specific.
> 
> To fix this, let's extend the VIDIOC_ENUM_FMT with a missing capability:
> enumerating pixel formats for a given media bus code. The media bus code
> is passed through the v4l2_fmtdesc structure in a new mbus_code field
> (repurposed from the reserved fields). With this capability in place,
> applications can enumerate pixel formats for a given media bus code
> without modifying the active configuration of the device.
> 
> The current behaviour of the ioctl is preserved when the new mbus_code
> field is set to 0, ensuring compatibility with existing userspace. The
> API extension is documented as mandatory for MC-centric devices (as
> advertised through the V4L2_CAP_IO_MC capability), allowing applications
> and compliance tools to easily determine the availability of the
> VIDIOC_ENUM_FMT extension.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

Regards,

	Hans

> ---
>  .../media/uapi/v4l/vidioc-enum-fmt.rst          | 17 ++++++++++++++---
>  drivers/media/v4l2-core/v4l2-ioctl.c            | 13 +++++++++++--
>  include/uapi/linux/videodev2.h                  |  3 ++-
>  3 files changed, 27 insertions(+), 6 deletions(-)
> 
> diff --git a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> index 8ca6ab701e4ab99c..82792d8e910b2313 100644
> --- a/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-enum-fmt.rst
> @@ -48,10 +48,21 @@ one until ``EINVAL`` is returned. If applicable, drivers shall return
>  formats in preference order, where preferred formats are returned before
>  (that is, with lower ``index`` value) less-preferred formats.
>  
> -.. note::
> +If the driver doesn't advertise the ``V4L2_CAP_IO_MC``
> +:ref:`device-capabilities <capability>`, applications shall initialize the
> +``mbus_code`` field to zero. Drivers shall enumerate all image formats supported
> +by the device. The enumerated formats may depend on the active input or output
> +of the device.
>  
> -   After switching input or output the list of enumerated image
> -   formats may be different.
> +If the driver advertises the ``V4L2_CAP_IO_MC`` :ref:`device-capabilities
> +<capability>`, applications may initialize the ``mbus_code`` to a valid
> +:ref:`v4l2_mbus_pixelcode <media bus format code>`. If the ``mbus_code` field
> +is not zero, drivers shall restrict enumeration to only the image formats that
> +can produce (for video output devices) or be produced from (for video capture
> +devices) that media bus code. Regardless of the value of the ``mbus_code``
> +field, the enumerated image formats shall not depend on the active
> +configuration of the video device or device pipeline. Enumeration shall
> +otherwise operate as previously described.
>  
>  
>  .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index afd1f427df557f71..3e7b99fa415222c6 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -264,12 +264,13 @@ static void v4l_print_fmtdesc(const void *arg, bool write_only)
>  {
>  	const struct v4l2_fmtdesc *p = arg;
>  
> -	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, description='%.*s'\n",
> +	pr_cont("index=%u, type=%s, flags=0x%x, pixelformat=%c%c%c%c, mbus_code=0x%04x, description='%.*s'\n",
>  		p->index, prt_names(p->type, v4l2_type_names),
>  		p->flags, (p->pixelformat & 0xff),
>  		(p->pixelformat >>  8) & 0xff,
>  		(p->pixelformat >> 16) & 0xff,
>  		(p->pixelformat >> 24) & 0xff,
> +		p->mbus_code,
>  		(int)sizeof(p->description), p->description);
>  }
>  
> @@ -1472,12 +1473,20 @@ static int v4l_enum_fmt(const struct v4l2_ioctl_ops *ops,
>  	struct video_device *vdev = video_devdata(file);
>  	struct v4l2_fmtdesc *p = arg;
>  	int ret = check_fmt(file, p->type);
> +	u32 mbus_code;
>  	u32 cap_mask;
>  
>  	if (ret)
>  		return ret;
>  	ret = -EINVAL;
>  
> +	if (p->mbus_code && !(vdev->device_caps & V4L2_CAP_IO_MC))
> +		return -EINVAL;
> +
> +	mbus_code = p->mbus_code;
> +	CLEAR_AFTER_FIELD(p, type);
> +	p->mbus_code = mbus_code;
> +
>  	switch (p->type) {
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE:
>  	case V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE:
> @@ -2757,7 +2766,7 @@ DEFINE_V4L_STUB_FUNC(dv_timings_cap)
>  
>  static const struct v4l2_ioctl_info v4l2_ioctls[] = {
>  	IOCTL_INFO(VIDIOC_QUERYCAP, v4l_querycap, v4l_print_querycap, 0),
> -	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> +	IOCTL_INFO(VIDIOC_ENUM_FMT, v4l_enum_fmt, v4l_print_fmtdesc, 0),
>  	IOCTL_INFO(VIDIOC_G_FMT, v4l_g_fmt, v4l_print_format, 0),
>  	IOCTL_INFO(VIDIOC_S_FMT, v4l_s_fmt, v4l_print_format, INFO_FL_PRIO),
>  	IOCTL_INFO(VIDIOC_REQBUFS, v4l_reqbufs, v4l_print_requestbuffers, INFO_FL_PRIO | INFO_FL_QUEUE),
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index b18f3f7cde31c2e4..c3a1cf1c507f5506 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -784,7 +784,8 @@ struct v4l2_fmtdesc {
>  	__u32               flags;
>  	__u8		    description[32];   /* Description string */
>  	__u32		    pixelformat;       /* Format fourcc      */
> -	__u32		    reserved[4];
> +	__u32		    mbus_code;		/* Media bus code    */
> +	__u32		    reserved[3];
>  };
>  
>  #define V4L2_FMT_FLAG_COMPRESSED		0x0001
>