diff options
| -rw-r--r-- | Documentation/userspace-api/media/v4l/user-func.rst | 1 | ||||
| -rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-subdev-g-client-cap.rst | 83 | ||||
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-subdev.c | 63 | ||||
| -rw-r--r-- | include/media/v4l2-subdev.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/v4l2-subdev.h | 21 |
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) |