usb: gadget: uvc: cleanup UVCG_FRAME_ATTR macro

1) Change "conv" an "vnoc" to "to_cpu_endian" to "to_little_endian".
2) No need to check the "limit" because that is already handled in
   kstrtoXX so delete that parameter along with the check.
3) By using a "bits" parameter, we can combine the "uxx" parameter and
   the "str2u" parameters.
4) The kstrtou##bits() conversion does not need to be done under the
   mutex so move it to the start of the function.
5) Change the name of "identity_conv" to "noop_conversion".
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/uvc_configfs.c

@@ -1030,7 +1030,7 @@ static struct configfs_item_operations uvcg_frame_item_ops = {
 	.store_attribute	= uvcg_frame_attr_store,
 };
 
-#define UVCG_FRAME_ATTR(cname, aname, conv, str2u, uxx, vnoc, limit)	\
+#define UVCG_FRAME_ATTR(cname, aname, to_cpu_endian, to_little_endian, bits) \
 static ssize_t uvcg_frame_##cname##_show(struct uvcg_frame *f, char *page)\
 {									\
 	struct f_uvc_opts *opts;					\
@@ -1044,7 +1044,7 @@ static ssize_t uvcg_frame_##cname##_show(struct uvcg_frame *f, char *page)\
 	opts = to_f_uvc_opts(opts_item);				\
 									\
 	mutex_lock(&opts->lock);					\
-	result = sprintf(page, "%d\n", conv(f->frame.cname));		\
+	result = sprintf(page, "%d\n", to_cpu_endian(f->frame.cname));	\
 	mutex_unlock(&opts->lock);					\
 									\
 	mutex_unlock(su_mutex);						\
@@ -1059,7 +1059,11 @@ static ssize_t  uvcg_frame_##cname##_store(struct uvcg_frame *f,	\
 	struct uvcg_format *fmt;					\
 	struct mutex *su_mutex = &f->item.ci_group->cg_subsys->su_mutex;\
 	int ret;							\
-	uxx num;							\
+	u##bits num;							\
+									\
+	ret = kstrtou##bits(page, 0, &num);				\
+	if (ret)							\
+		return ret;						\
 									\
 	mutex_lock(su_mutex); /* for navigating configfs hierarchy */	\
 									\
@@ -1073,15 +1077,7 @@ static ssize_t  uvcg_frame_##cname##_store(struct uvcg_frame *f,	\
 		goto end;						\
 	}								\
 									\
-	ret = str2u(page, 0, &num);					\
-	if (ret)							\
-		goto end;						\
-									\
-	if (num > limit) {						\
-		ret = -EINVAL;						\
-		goto end;						\
-	}								\
-	f->frame.cname = vnoc(num);					\
+	f->frame.cname = to_little_endian(num);				\
 	ret = len;							\
 end:									\
 	mutex_unlock(&opts->lock);					\
@@ -1095,24 +1091,20 @@ static struct uvcg_frame_attribute					\
 			uvcg_frame_##cname##_show,			\
 			uvcg_frame_##cname##_store)
 
-#define identity_conv(x) (x)
+#define noop_conversion(x) (x)
 
-UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, identity_conv, kstrtou8, u8,
-		identity_conv, 0xFF);
-UVCG_FRAME_ATTR(w_width, wWidth, le16_to_cpu, kstrtou16, u16, cpu_to_le16,
-		0xFFFF);
-UVCG_FRAME_ATTR(w_height, wHeight, le16_to_cpu, kstrtou16, u16, cpu_to_le16,
-		0xFFFF);
-UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, le32_to_cpu, kstrtou32, u32,
-		cpu_to_le32, 0xFFFFFFFF);
-UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, le32_to_cpu, kstrtou32, u32,
-		cpu_to_le32, 0xFFFFFFFF);
+UVCG_FRAME_ATTR(bm_capabilities, bmCapabilities, noop_conversion,
+		noop_conversion, 8);
+UVCG_FRAME_ATTR(w_width, wWidth, le16_to_cpu, cpu_to_le16, 16);
+UVCG_FRAME_ATTR(w_height, wHeight, le16_to_cpu, cpu_to_le16, 16);
+UVCG_FRAME_ATTR(dw_min_bit_rate, dwMinBitRate, le32_to_cpu, cpu_to_le32, 32);
+UVCG_FRAME_ATTR(dw_max_bit_rate, dwMaxBitRate, le32_to_cpu, cpu_to_le32, 32);
 UVCG_FRAME_ATTR(dw_max_video_frame_buffer_size, dwMaxVideoFrameBufferSize,
-		le32_to_cpu, kstrtou32, u32, cpu_to_le32, 0xFFFFFFFF);
+		le32_to_cpu, cpu_to_le32, 32);
 UVCG_FRAME_ATTR(dw_default_frame_interval, dwDefaultFrameInterval,
-		le32_to_cpu, kstrtou32, u32, cpu_to_le32, 0xFFFFFFFF);
+		le32_to_cpu, cpu_to_le32, 32);
 
-#undef identity_conv
+#undef noop_conversion
 
 #undef UVCG_FRAME_ATTR