Commit 5f0e659d authored by Laurent Pinchart's avatar Laurent Pinchart
Browse files

media: uvcvideo: Factor out usb_string() calls 



When parsing UVC descriptors to instantiate entities, the driver calls
usb_string() to retrieve the entity name from the device, and falls back
to a default name if the string can't be retrieved. This code pattern
occurs multiple times. Factor it out to a separate helper function.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 81e78a6f

drivers/media/usb/uvc/uvc_driver.c

+35 −24
Original line number Diff line number Diff line
@@ -794,6 +794,27 @@ static struct uvc_entity *uvc_alloc_entity(u16 type, u16 id, 
	return entity;

}



static void uvc_entity_set_name(struct uvc_device *dev, struct uvc_entity *entity,

				const char *type_name, u8 string_id)

{

	int ret;



	/*

	 * First attempt to read the entity name from the device. If the entity

	 * has no associated string, or if reading the string fails (most

	 * likely due to a buggy firmware), fall back to default names based on

	 * the entity type.

	 */

	if (string_id) {

		ret = usb_string(dev->udev, string_id, entity->name,

				 sizeof(entity->name));

		if (!ret)

			return;

	}



	sprintf(entity->name, "%s %u", type_name, entity->id);

}



/* Parse vendor-specific extensions. */

static int uvc_parse_vendor_control(struct uvc_device *dev,

	const unsigned char *buffer, int buflen)
@@ -860,9 +881,7 @@ static int uvc_parse_vendor_control(struct uvc_device *dev, 
					       + n;

		memcpy(unit->extension.bmControls, &buffer[23+p], 2*n);



		if (buffer[24+p+2*n] == 0 ||

		    usb_string(udev, buffer[24+p+2*n], unit->name, sizeof(unit->name)) < 0)

			sprintf(unit->name, "Extension %u", buffer[3]);

		uvc_entity_set_name(dev, unit, "Extension", buffer[24+p+2*n]);



		list_add_tail(&unit->list, &dev->entities);

		handled = 1;
@@ -880,6 +899,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 
	struct usb_interface *intf;

	struct usb_host_interface *alts = dev->intf->cur_altsetting;

	unsigned int i, n, p, len;

	const char *type_name;

	u16 type;



	switch (buffer[2]) {
@@ -985,15 +1005,14 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 
			memcpy(term->media.bmTransportModes, &buffer[10+n], p);

		}



		if (buffer[7] == 0 ||

		    usb_string(udev, buffer[7], term->name, sizeof(term->name)) < 0) {

		if (UVC_ENTITY_TYPE(term) == UVC_ITT_CAMERA)

				sprintf(term->name, "Camera %u", buffer[3]);

			if (UVC_ENTITY_TYPE(term) == UVC_ITT_MEDIA_TRANSPORT_INPUT)

				sprintf(term->name, "Media %u", buffer[3]);

			type_name = "Camera";

		else if (UVC_ENTITY_TYPE(term) == UVC_ITT_MEDIA_TRANSPORT_INPUT)

			type_name = "Media";

		else

				sprintf(term->name, "Input %u", buffer[3]);

		}

			type_name = "Input";



		uvc_entity_set_name(dev, term, type_name, buffer[7]);



		list_add_tail(&term->list, &dev->entities);

		break;
@@ -1026,9 +1045,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 


		memcpy(term->baSourceID, &buffer[7], 1);



		if (buffer[8] == 0 ||

		    usb_string(udev, buffer[8], term->name, sizeof(term->name)) < 0)

			sprintf(term->name, "Output %u", buffer[3]);

		uvc_entity_set_name(dev, term, "Output", buffer[8]);



		list_add_tail(&term->list, &dev->entities);

		break;
@@ -1049,9 +1066,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 


		memcpy(unit->baSourceID, &buffer[5], p);



		if (buffer[5+p] == 0 ||

		    usb_string(udev, buffer[5+p], unit->name, sizeof(unit->name)) < 0)

			sprintf(unit->name, "Selector %u", buffer[3]);

		uvc_entity_set_name(dev, unit, "Selector", buffer[5+p]);



		list_add_tail(&unit->list, &dev->entities);

		break;
@@ -1080,9 +1095,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 
		if (dev->uvc_version >= 0x0110)

			unit->processing.bmVideoStandards = buffer[9+n];



		if (buffer[8+n] == 0 ||

		    usb_string(udev, buffer[8+n], unit->name, sizeof(unit->name)) < 0)

			sprintf(unit->name, "Processing %u", buffer[3]);

		uvc_entity_set_name(dev, unit, "Processing", buffer[8+n]);



		list_add_tail(&unit->list, &dev->entities);

		break;
@@ -1109,9 +1122,7 @@ static int uvc_parse_standard_control(struct uvc_device *dev, 
		unit->extension.bmControls = (u8 *)unit + sizeof(*unit);

		memcpy(unit->extension.bmControls, &buffer[23+p], n);



		if (buffer[23+p+n] == 0 ||

		    usb_string(udev, buffer[23+p+n], unit->name, sizeof(unit->name)) < 0)

			sprintf(unit->name, "Extension %u", buffer[3]);

		uvc_entity_set_name(dev, unit, "Extension", buffer[23+p+n]);



		list_add_tail(&unit->list, &dev->entities);

		break;