diff options
Diffstat (limited to 'drivers/usb/gadget/function/uvc_configfs.c')
| -rw-r--r-- | drivers/usb/gadget/function/uvc_configfs.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/uvc_configfs.c b/drivers/usb/gadget/function/uvc_configfs.c index 51d8e9ee5323..3c0467bcb14f 100644 --- a/drivers/usb/gadget/function/uvc_configfs.c +++ b/drivers/usb/gadget/function/uvc_configfs.c @@ -1918,6 +1918,25 @@ enum uvcg_strm_type { UVCG_FRAME }; +/* + * Iterate over a hierarchy of streaming descriptors' config items. + * The items are created by the user with configfs. + * + * It "processes" the header pointed to by @priv1, then for each format + * that follows the header "processes" the format itself and then for + * each frame inside a format "processes" the frame. + * + * As a "processing" function the @fun is used. + * + * __uvcg_iter_strm_cls() is used in two context: first, to calculate + * the amount of memory needed for an array of streaming descriptors + * and second, to actually fill the array. + * + * @h: streaming header pointer + * @priv2: an "inout" parameter (the caller might want to see the changes to it) + * @priv3: an "inout" parameter (the caller might want to see the changes to it) + * @fun: callback function for processing each level of the hierarchy + */ static int __uvcg_iter_strm_cls(struct uvcg_streaming_header *h, void *priv2, void *priv3, int (*fun)(void *, void *, void *, int, enum uvcg_strm_type type)) @@ -1951,6 +1970,14 @@ static int __uvcg_iter_strm_cls(struct uvcg_streaming_header *h, return ret; } +/* + * Count how many bytes are needed for an array of streaming descriptors. + * + * @priv1: pointer to a header, format or frame + * @priv2: inout parameter, accumulated size of the array + * @priv3: inout parameter, accumulated number of the array elements + * @n: unused, this function's prototype must match @fun in __uvcg_iter_strm_cls + */ static int __uvcg_cnt_strm(void *priv1, void *priv2, void *priv3, int n, enum uvcg_strm_type type) { @@ -2000,6 +2027,13 @@ static int __uvcg_cnt_strm(void *priv1, void *priv2, void *priv3, int n, return 0; } +/* + * Fill an array of streaming descriptors. + * + * @priv1: pointer to a header, format or frame + * @priv2: inout parameter, pointer into a block of memory + * @priv3: inout parameter, pointer to a 2-dimensional array + */ static int __uvcg_fill_strm(void *priv1, void *priv2, void *priv3, int n, enum uvcg_strm_type type) { |