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-rw-r--r--Documentation/userspace-api/media/v4l/user-func.rst1
-rw-r--r--Documentation/userspace-api/media/v4l/vidioc-subdev-g-client-cap.rst83
-rw-r--r--drivers/media/v4l2-core/v4l2-subdev.c63
-rw-r--r--include/media/v4l2-subdev.h1
-rw-r--r--include/uapi/linux/v4l2-subdev.h21
5 files changed, 169 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst
index 228c1521f190..15ff0bf7bbe6 100644
--- a/Documentation/userspace-api/media/v4l/user-func.rst
+++ b/Documentation/userspace-api/media/v4l/user-func.rst
@@ -72,6 +72,7 @@ Function Reference
vidioc-subdev-g-frame-interval
vidioc-subdev-g-routing
vidioc-subdev-g-selection
+ vidioc-subdev-g-client-cap
vidioc-subdev-querycap
vidioc-subscribe-event
func-mmap
diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-client-cap.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-client-cap.rst
new file mode 100644
index 000000000000..20f12a1cc0f7
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-client-cap.rst
@@ -0,0 +1,83 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: V4L
+
+.. _VIDIOC_SUBDEV_G_CLIENT_CAP:
+
+************************************************************
+ioctl VIDIOC_SUBDEV_G_CLIENT_CAP, VIDIOC_SUBDEV_S_CLIENT_CAP
+************************************************************
+
+Name
+====
+
+VIDIOC_SUBDEV_G_CLIENT_CAP - VIDIOC_SUBDEV_S_CLIENT_CAP - Get or set client
+capabilities.
+
+Synopsis
+========
+
+.. c:macro:: VIDIOC_SUBDEV_G_CLIENT_CAP
+
+``int ioctl(int fd, VIDIOC_SUBDEV_G_CLIENT_CAP, struct v4l2_subdev_client_capability *argp)``
+
+.. c:macro:: VIDIOC_SUBDEV_S_CLIENT_CAP
+
+``int ioctl(int fd, VIDIOC_SUBDEV_S_CLIENT_CAP, struct v4l2_subdev_client_capability *argp)``
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :ref:`open() <func-open>`.
+
+``argp``
+ Pointer to struct :c:type:`v4l2_subdev_client_capability`.
+
+Description
+===========
+
+These ioctls are used to get and set the client (the application using the
+subdevice ioctls) capabilities. The client capabilities are stored in the file
+handle of the opened subdev device node, and the client must set the
+capabilities for each opened subdev separately.
+
+By default no client capabilities are set when a subdev device node is opened.
+
+The purpose of the client capabilities are to inform the kernel of the behavior
+of the client, mainly related to maintaining compatibility with different
+kernel and userspace versions.
+
+The ``VIDIOC_SUBDEV_G_CLIENT_CAP`` ioctl returns the current client capabilities
+associated with the file handle ``fd``.
+
+The ``VIDIOC_SUBDEV_S_CLIENT_CAP`` ioctl sets client capabilities for the file
+handle ``fd``. The new capabilities fully replace the current capabilities, the
+ioctl can therefore also be used to remove capabilities that have previously
+been set.
+
+``VIDIOC_SUBDEV_S_CLIENT_CAP`` modifies the struct
+:c:type:`v4l2_subdev_client_capability` to reflect the capabilities that have
+been accepted. A common case for the kernel not accepting a capability is that
+the kernel is older than the headers the userspace uses, and thus the capability
+is unknown to the kernel.
+
+.. flat-table:: Client Capabilities
+ :header-rows: 1
+
+ * - Capability
+ - Description
+ * - ``V4L2_SUBDEV_CLIENT_CAP_STREAMS``
+ - The client is aware of streams. Setting this flag enables the use
+ of 'stream' fields (referring to the stream number) with various
+ ioctls. If this is not set (which is the default), the 'stream' fields
+ will be forced to 0 by the kernel.
+
+Return Value
+============
+
+On success 0 is returned, on error -1 and the ``errno`` variable is set
+appropriately. The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.
+
+ENOIOCTLCMD
+ The kernel does not support this ioctl.
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index bfb102f2121a..2ec179cd1264 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -510,8 +510,11 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
struct video_device *vdev = video_devdata(file);
struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
struct v4l2_fh *vfh = file->private_data;
+ struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
bool ro_subdev = test_bit(V4L2_FL_SUBDEV_RO_DEVNODE, &vdev->flags);
bool streams_subdev = sd->flags & V4L2_SUBDEV_FL_STREAMS;
+ bool client_supports_streams = subdev_fh->client_caps &
+ V4L2_SUBDEV_CLIENT_CAP_STREAMS;
int rval;
switch (cmd) {
@@ -636,6 +639,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_G_FMT: {
struct v4l2_subdev_format *format = arg;
+ if (!client_supports_streams)
+ format->stream = 0;
+
memset(format->reserved, 0, sizeof(format->reserved));
memset(format->format.reserved, 0, sizeof(format->format.reserved));
return v4l2_subdev_call(sd, pad, get_fmt, state, format);
@@ -647,6 +653,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
if (format->which != V4L2_SUBDEV_FORMAT_TRY && ro_subdev)
return -EPERM;
+ if (!client_supports_streams)
+ format->stream = 0;
+
memset(format->reserved, 0, sizeof(format->reserved));
memset(format->format.reserved, 0, sizeof(format->format.reserved));
return v4l2_subdev_call(sd, pad, set_fmt, state, format);
@@ -656,6 +665,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
struct v4l2_subdev_crop *crop = arg;
struct v4l2_subdev_selection sel;
+ if (!client_supports_streams)
+ crop->stream = 0;
+
memset(crop->reserved, 0, sizeof(crop->reserved));
memset(&sel, 0, sizeof(sel));
sel.which = crop->which;
@@ -677,6 +689,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
if (crop->which != V4L2_SUBDEV_FORMAT_TRY && ro_subdev)
return -EPERM;
+ if (!client_supports_streams)
+ crop->stream = 0;
+
memset(crop->reserved, 0, sizeof(crop->reserved));
memset(&sel, 0, sizeof(sel));
sel.which = crop->which;
@@ -695,6 +710,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_ENUM_MBUS_CODE: {
struct v4l2_subdev_mbus_code_enum *code = arg;
+ if (!client_supports_streams)
+ code->stream = 0;
+
memset(code->reserved, 0, sizeof(code->reserved));
return v4l2_subdev_call(sd, pad, enum_mbus_code, state,
code);
@@ -703,6 +721,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_ENUM_FRAME_SIZE: {
struct v4l2_subdev_frame_size_enum *fse = arg;
+ if (!client_supports_streams)
+ fse->stream = 0;
+
memset(fse->reserved, 0, sizeof(fse->reserved));
return v4l2_subdev_call(sd, pad, enum_frame_size, state,
fse);
@@ -711,6 +732,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_G_FRAME_INTERVAL: {
struct v4l2_subdev_frame_interval *fi = arg;
+ if (!client_supports_streams)
+ fi->stream = 0;
+
memset(fi->reserved, 0, sizeof(fi->reserved));
return v4l2_subdev_call(sd, video, g_frame_interval, arg);
}
@@ -721,6 +745,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
if (ro_subdev)
return -EPERM;
+ if (!client_supports_streams)
+ fi->stream = 0;
+
memset(fi->reserved, 0, sizeof(fi->reserved));
return v4l2_subdev_call(sd, video, s_frame_interval, arg);
}
@@ -728,6 +755,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL: {
struct v4l2_subdev_frame_interval_enum *fie = arg;
+ if (!client_supports_streams)
+ fie->stream = 0;
+
memset(fie->reserved, 0, sizeof(fie->reserved));
return v4l2_subdev_call(sd, pad, enum_frame_interval, state,
fie);
@@ -736,6 +766,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
case VIDIOC_SUBDEV_G_SELECTION: {
struct v4l2_subdev_selection *sel = arg;
+ if (!client_supports_streams)
+ sel->stream = 0;
+
memset(sel->reserved, 0, sizeof(sel->reserved));
return v4l2_subdev_call(
sd, pad, get_selection, state, sel);
@@ -747,6 +780,9 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
if (sel->which != V4L2_SUBDEV_FORMAT_TRY && ro_subdev)
return -EPERM;
+ if (!client_supports_streams)
+ sel->stream = 0;
+
memset(sel->reserved, 0, sizeof(sel->reserved));
return v4l2_subdev_call(
sd, pad, set_selection, state, sel);
@@ -888,6 +924,33 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg,
routing->which, &krouting);
}
+ case VIDIOC_SUBDEV_G_CLIENT_CAP: {
+ struct v4l2_subdev_client_capability *client_cap = arg;
+
+ client_cap->capabilities = subdev_fh->client_caps;
+
+ return 0;
+ }
+
+ case VIDIOC_SUBDEV_S_CLIENT_CAP: {
+ struct v4l2_subdev_client_capability *client_cap = arg;
+
+ /*
+ * Clear V4L2_SUBDEV_CLIENT_CAP_STREAMS if streams API is not
+ * enabled. Remove this when streams API is no longer
+ * experimental.
+ */
+ if (!v4l2_subdev_enable_streams_api)
+ client_cap->capabilities &= ~V4L2_SUBDEV_CLIENT_CAP_STREAMS;
+
+ /* Filter out unsupported capabilities */
+ client_cap->capabilities &= V4L2_SUBDEV_CLIENT_CAP_STREAMS;
+
+ subdev_fh->client_caps = client_cap->capabilities;
+
+ return 0;
+ }
+
default:
return v4l2_subdev_call(sd, core, ioctl, cmd, arg);
}
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 1d2877700cdb..cfd19e72d0fc 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -1125,6 +1125,7 @@ struct v4l2_subdev_fh {
struct module *owner;
#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
struct v4l2_subdev_state *state;
+ u64 client_caps;
#endif
};
diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h
index 654d659de835..4a195b68f28f 100644
--- a/include/uapi/linux/v4l2-subdev.h
+++ b/include/uapi/linux/v4l2-subdev.h
@@ -233,6 +233,24 @@ struct v4l2_subdev_routing {
__u32 reserved[6];
};
+/*
+ * The client is aware of streams. Setting this flag enables the use of 'stream'
+ * fields (referring to the stream number) with various ioctls. If this is not
+ * set (which is the default), the 'stream' fields will be forced to 0 by the
+ * kernel.
+ */
+ #define V4L2_SUBDEV_CLIENT_CAP_STREAMS (1U << 0)
+
+/**
+ * struct v4l2_subdev_client_capability - Capabilities of the client accessing
+ * the subdev
+ *
+ * @capabilities: A bitmask of V4L2_SUBDEV_CLIENT_CAP_* flags.
+ */
+struct v4l2_subdev_client_capability {
+ __u64 capabilities;
+};
+
/* Backwards compatibility define --- to be removed */
#define v4l2_subdev_edid v4l2_edid
@@ -250,6 +268,9 @@ struct v4l2_subdev_routing {
#define VIDIOC_SUBDEV_S_SELECTION _IOWR('V', 62, struct v4l2_subdev_selection)
#define VIDIOC_SUBDEV_G_ROUTING _IOWR('V', 38, struct v4l2_subdev_routing)
#define VIDIOC_SUBDEV_S_ROUTING _IOWR('V', 39, struct v4l2_subdev_routing)
+#define VIDIOC_SUBDEV_G_CLIENT_CAP _IOR('V', 101, struct v4l2_subdev_client_capability)
+#define VIDIOC_SUBDEV_S_CLIENT_CAP _IOWR('V', 102, struct v4l2_subdev_client_capability)
+
/* The following ioctls are identical to the ioctls in videodev2.h */
#define VIDIOC_SUBDEV_G_STD _IOR('V', 23, v4l2_std_id)
#define VIDIOC_SUBDEV_S_STD _IOW('V', 24, v4l2_std_id)
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