[media] uvcvideo: Add UVCIOC_CTRL_QUERY ioctl
This ioctl extends UVCIOC_CTRL_GET/SET by not only allowing to get/set
XU controls but to also send arbitrary UVC commands to XU controls,
namely GET_CUR, SET_CUR, GET_MIN, GET_MAX, GET_RES, GET_LEN, GET_INFO
and GET_DEF. This is required for applications to work with XU controls,
so that they can properly query the size and allocate the necessary
buffers.
Signed-off-by: Martin Rubli <martin_rubli@logitech.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index 59f8a9a..47175cc 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -1344,32 +1344,33 @@
}
int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
- struct uvc_xu_control *xctrl, int set)
+ struct uvc_xu_control_query *xqry)
{
struct uvc_entity *entity;
- struct uvc_control *ctrl = NULL;
+ struct uvc_control *ctrl;
unsigned int i, found = 0;
- int restore = 0;
- __u8 *data;
+ __u32 reqflags;
+ __u16 size;
+ __u8 *data = NULL;
int ret;
/* Find the extension unit. */
list_for_each_entry(entity, &chain->entities, chain) {
if (UVC_ENTITY_TYPE(entity) == UVC_VC_EXTENSION_UNIT &&
- entity->id == xctrl->unit)
+ entity->id == xqry->unit)
break;
}
- if (entity->id != xctrl->unit) {
+ if (entity->id != xqry->unit) {
uvc_trace(UVC_TRACE_CONTROL, "Extension unit %u not found.\n",
- xctrl->unit);
- return -EINVAL;
+ xqry->unit);
+ return -ENOENT;
}
/* Find the control and perform delayed initialization if needed. */
for (i = 0; i < entity->ncontrols; ++i) {
ctrl = &entity->controls[i];
- if (ctrl->index == xctrl->selector - 1) {
+ if (ctrl->index == xqry->selector - 1) {
found = 1;
break;
}
@@ -1377,8 +1378,8 @@
if (!found) {
uvc_trace(UVC_TRACE_CONTROL, "Control %pUl/%u not found.\n",
- entity->extension.guidExtensionCode, xctrl->selector);
- return -EINVAL;
+ entity->extension.guidExtensionCode, xqry->selector);
+ return -ENOENT;
}
if (mutex_lock_interruptible(&chain->ctrl_mutex))
@@ -1390,43 +1391,72 @@
goto done;
}
- /* Validate control data size. */
- if (ctrl->info.size != xctrl->size) {
+ /* Validate the required buffer size and flags for the request */
+ reqflags = 0;
+ size = ctrl->info.size;
+
+ switch (xqry->query) {
+ case UVC_GET_CUR:
+ reqflags = UVC_CONTROL_GET_CUR;
+ break;
+ case UVC_GET_MIN:
+ reqflags = UVC_CONTROL_GET_MIN;
+ break;
+ case UVC_GET_MAX:
+ reqflags = UVC_CONTROL_GET_MAX;
+ break;
+ case UVC_GET_DEF:
+ reqflags = UVC_CONTROL_GET_DEF;
+ break;
+ case UVC_GET_RES:
+ reqflags = UVC_CONTROL_GET_RES;
+ break;
+ case UVC_SET_CUR:
+ reqflags = UVC_CONTROL_SET_CUR;
+ break;
+ case UVC_GET_LEN:
+ size = 2;
+ break;
+ case UVC_GET_INFO:
+ size = 1;
+ break;
+ default:
ret = -EINVAL;
goto done;
}
- if ((set && !(ctrl->info.flags & UVC_CONTROL_SET_CUR)) ||
- (!set && !(ctrl->info.flags & UVC_CONTROL_GET_CUR))) {
- ret = -EINVAL;
+ if (size != xqry->size) {
+ ret = -ENOBUFS;
goto done;
}
- memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
- uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
- ctrl->info.size);
- data = uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT);
- restore = set;
+ if (reqflags && !(ctrl->info.flags & reqflags)) {
+ ret = -EBADRQC;
+ goto done;
+ }
- if (set && copy_from_user(data, xctrl->data, xctrl->size)) {
+ data = kmalloc(size, GFP_KERNEL);
+ if (data == NULL) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ if (xqry->query == UVC_SET_CUR &&
+ copy_from_user(data, xqry->data, size)) {
ret = -EFAULT;
goto done;
}
- ret = uvc_query_ctrl(chain->dev, set ? UVC_SET_CUR : UVC_GET_CUR,
- xctrl->unit, chain->dev->intfnum, xctrl->selector,
- data, xctrl->size);
+ ret = uvc_query_ctrl(chain->dev, xqry->query, xqry->unit,
+ chain->dev->intfnum, xqry->selector, data, size);
if (ret < 0)
goto done;
- if (!set && copy_to_user(xctrl->data, data, xctrl->size))
+ if (xqry->query != UVC_SET_CUR &&
+ copy_to_user(xqry->data, data, size))
ret = -EFAULT;
done:
- if (ret && restore)
- memcpy(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
- uvc_ctrl_data(ctrl, UVC_CTRL_DATA_BACKUP),
- xctrl->size);
-
+ kfree(data);
mutex_unlock(&chain->ctrl_mutex);
return ret;
}