Commit fe78d187 authored by Martin Rubli's avatar Martin Rubli Committed by Mauro Carvalho Chehab
Browse files

[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: default avatarMartin Rubli <martin_rubli@logitech.com>
Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 837d50b5

drivers/media/video/uvc/uvc_ctrl.c

+61 −31
Original line number Diff line number Diff line
@@ -1344,32 +1344,33 @@ static int uvc_ctrl_init_xu_ctrl(struct uvc_device *dev, 
}



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 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain, 


	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 @@ int uvc_xu_ctrl_query(struct uvc_video_chain *chain, 
		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;

}

drivers/media/video/uvc/uvc_v4l2.c

+16 −3
Original line number Diff line number Diff line
@@ -1029,10 +1029,23 @@ static long uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg) 
					  cmd == UVCIOC_CTRL_MAP_OLD);



	case UVCIOC_CTRL_GET:

		return uvc_xu_ctrl_query(chain, arg, 0);



	case UVCIOC_CTRL_SET:

		return uvc_xu_ctrl_query(chain, arg, 1);

	{

		struct uvc_xu_control *xctrl = arg;

		struct uvc_xu_control_query xqry = {

			.unit		= xctrl->unit,

			.selector	= xctrl->selector,

			.query		= cmd == UVCIOC_CTRL_GET

					? UVC_GET_CUR : UVC_SET_CUR,

			.size		= xctrl->size,

			.data		= xctrl->data,

		};



		return uvc_xu_ctrl_query(chain, &xqry);

	}



	case UVCIOC_CTRL_QUERY:

		return uvc_xu_ctrl_query(chain, arg);



	default:

		uvc_trace(UVC_TRACE_IOCTL, "Unknown ioctl 0x%08x\n", cmd);

drivers/media/video/uvc/uvcvideo.h

+11 −2
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ struct uvc_xu_control_mapping { 


	__u8 size;

	__u8 offset;

	enum v4l2_ctrl_type v4l2_type;

	__u32 v4l2_type;

	__u32 data_type;



	struct uvc_menu_info __user *menu_info;
@@ -73,11 +73,20 @@ struct uvc_xu_control { 
	__u8 __user *data;

};



struct uvc_xu_control_query {

	__u8 unit;

	__u8 selector;

	__u8 query;

	__u16 size;

	__u8 __user *data;

};



#define UVCIOC_CTRL_ADD		_IOW('U', 1, struct uvc_xu_control_info)

#define UVCIOC_CTRL_MAP_OLD	_IOWR('U', 2, struct uvc_xu_control_mapping_old)

#define UVCIOC_CTRL_MAP		_IOWR('U', 2, struct uvc_xu_control_mapping)

#define UVCIOC_CTRL_GET		_IOWR('U', 3, struct uvc_xu_control)

#define UVCIOC_CTRL_SET		_IOW('U', 4, struct uvc_xu_control)

#define UVCIOC_CTRL_QUERY	_IOWR('U', 5, struct uvc_xu_control_query)



#ifdef __KERNEL__
@@ -638,7 +647,7 @@ extern int uvc_ctrl_set(struct uvc_video_chain *chain, 
		struct v4l2_ext_control *xctrl);



extern int uvc_xu_ctrl_query(struct uvc_video_chain *chain,

		struct uvc_xu_control *ctrl, int set);

		struct uvc_xu_control_query *xqry);



/* Utility functions */

extern void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,