While normal video/radio/vbi/swradio nodes have a proper QUERYCAP ioctl that apps can call to determine that it is indeed a V4L2 device, there is currently no equivalent for v4l-subdev nodes. Adding this ioctl will solve that, and it will allow utilities like v4l2-compliance to be used with these devices as well. SUBDEV_QUERYCAP currently returns the version and capabilities of the subdevice. Define a capability flag to report if the subdevice is registered in read-only mode.
Unified · Split
| @@ -15,6 +15,7 @@ · 14 unmodified lines | ||
| 15 | 15 | #include <linux/types.h> |
| 16 | 16 | #include <linux/videodev2.h> |
| 17 | 17 | #include <linux/export.h> |
| 18 | +#include <linux/version.h> | |
| 18 | 19 | |
| 19 | 20 | #include <media/v4l2-ctrls.h> |
| 20 | 21 | #include <media/v4l2-device.h> |
| @@ -344,6 +345,16 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) · 323 unmodified lines | ||
| 344 | 345 | int rval; |
| 345 | 346 | |
| 346 | 347 | switch (cmd) { |
| 348 | + case VIDIOC_SUBDEV_QUERYCAP: { | |
| 349 | + struct v4l2_subdev_capability *cap = arg; | |
| 350 | + | |
| 351 | + memset(cap->reserved, 0, sizeof(cap->reserved)); | |
| 352 | + cap->version = LINUX_VERSION_CODE; | |
| 353 | + cap->capabilities = ro_subdev ? V4L2_SUBDEV_CAP_RO_SUBDEV : 0; | |
| 354 | + | |
| 355 | + return 0; | |
| 356 | + } | |
| 357 | + | |
| 347 | 358 | case VIDIOC_QUERYCTRL: |
| 348 | 359 | /* |
| 349 | 360 | * TODO: this really should be folded into v4l2_queryctrl (this |
| @@ -155,9 +155,25 @@ struct v4l2_subdev_selection { · 154 unmodified lines | ||
| 155 | 155 | __u32 reserved[8]; |
| 156 | 156 | }; |
| 157 | 157 | |
| 158 | +/** | |
| 159 | + * struct v4l2_subdev_capability - subdev capabilities | |
| 160 | + * @version: the driver versioning number | |
| 161 | + * @capabilities: the subdev capabilities, see V4L2_SUBDEV_CAP_* | |
| 162 | + * @reserved: for future use, set to zero for now | |
| 163 | + */ | |
| 164 | +struct v4l2_subdev_capability { | |
| 165 | + __u32 version; | |
| 166 | + __u32 capabilities; | |
| 167 | + __u32 reserved[14]; | |
| 168 | +}; | |
| 169 | + | |
| 170 | +/* The v4l2 sub-device video device node is registered in read-only mode. */ | |
| 171 | +#define V4L2_SUBDEV_CAP_RO_SUBDEV BIT(0) | |
| 172 | + | |
| 158 | 173 | /* Backwards compatibility define --- to be removed */ |
| 159 | 174 | #define v4l2_subdev_edid v4l2_edid |
| 160 | 175 | |
| 176 | +#define VIDIOC_SUBDEV_QUERYCAP _IOR('V', 0, struct v4l2_subdev_capability) | |
| 161 | 177 | #define VIDIOC_SUBDEV_G_FMT _IOWR('V', 4, struct v4l2_subdev_format) |
| 162 | 178 | #define VIDIOC_SUBDEV_S_FMT _IOWR('V', 5, struct v4l2_subdev_format) |
| 163 | 179 | #define VIDIOC_SUBDEV_G_FRAME_INTERVAL _IOWR('V', 21, struct v4l2_subdev_frame_interval) |