usb: gadget: uvc: configfs: Add bFrameIndex attributes

From: Paul Elder <[email protected]>

The UVC frame descriptions are numbered using the descriptor's bFrameIndex field. The index is used in UVC requests, and is thus needed to handle requests in userspace. Make it dynamically discoverable by exposing it in a bFrameIndex configfs attribute of the frame config item.

However, the bFrameIndex value is never set to begin with. Set these values when linking the stream class header in the configfs hierarchy, and store it in the config item private data.

Signed-off-by Paul Elder <[email protected]>

---
 drivers/usb/gadget/function/uvc_configfs.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

(quoted diff) +0 -0

b/drivers/usb/gadget/function/uvc_configfs.c index 0ad6ea57d0b7..882d9963b244 100644

drivers/usb/gadget/function/uvc_configfs.c +3 -0

@@ -1152,6 +1152,8 @@ UVC_ATTR(uvcg_frame_, cname, aname);
 
 #define noop_conversion(x) (x)
 
+UVCG_FRAME_ATTR_RO(b_frame_index, bFrameIndex, noop_conversion,
+		noop_conversion, 8);
 UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, noop_conversion,
 		noop_conversion, 8);
 UVCG_FRAME_ATTR(w_width, wWidth, le16_to_cpu, cpu_to_le16, 16);

@@ -1298,6 +1300,7 @@ static ssize_t
 uvcg_frame_dw_frame_interval_store(struct config_item *item,
 UVC_ATTR(uvcg_frame_, dw_frame_interval, dwFrameInterval);
 
 static struct configfs_attribute *uvcg_frame_attrs[] = {
+	&uvcg_frame_attr_b_frame_index,
 	&uvcg_frame_attr_bm_capabilities,
 	&uvcg_frame_attr_w_width,

drivers/usb/gadget/function/uvc_configfs.c +1 -1

 	&uvcg_frame_attr_w_height,

@@ -2130,12 +2133,15 @@ static int __uvcg_fill_strm(void *priv1, void
 *priv2, void *priv3, int n, sizeof(*frm->dw_frame_interval);
 		memcpy(*dest, frm->dw_frame_interval, sz);
 		*dest += sz;
-		if (frm->fmt_type == UVCG_UNCOMPRESSED)
+		if (frm->fmt_type == UVCG_UNCOMPRESSED) {
 			h->bLength = UVC_DT_FRAME_UNCOMPRESSED_SIZE(
 				frm->frame.b_frame_interval_type);