[PATCH v7 6/7] media: uvcvideo: support V4L2_CTRL_WHICH_MIN/MAX_VAL

[Yunke Cao <yunkec@google.com>]

Add support for V4L2_CTRL_WHICH_MIN/MAX_VAL in uvc driver.
It is useful for the V4L2_CID_UVC_REGION_OF_INTEREST_RECT control.

Signed-off-by: Yunke Cao <yunkec@google.com>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 73 ++++++++++++++++++++++++++------
 drivers/media/usb/uvc/uvc_v4l2.c | 11 +++--
 drivers/media/usb/uvc/uvcvideo.h |  3 +-
 3 files changed, 70 insertions(+), 17 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 00482269233a..b569d6824ac1 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1923,7 +1923,7 @@ int uvc_ctrl_get(struct uvc_video_chain *chain,
 }
 
 int __uvc_ctrl_get_fixed_std(struct uvc_video_chain *chain,
-			     struct v4l2_ext_control *xctrl)
+			     struct v4l2_ext_control *xctrl, u32 v4l2_which)
 {
 	struct v4l2_queryctrl qc = { .id = xctrl->id };
 	int ret = uvc_query_v4l2_ctrl(chain, &qc);
@@ -1931,16 +1931,69 @@ int __uvc_ctrl_get_fixed_std(struct uvc_video_chain *chain,
 	if (ret < 0)
 		return ret;
 
-	xctrl->value = qc.default_value;
+	switch (v4l2_which) {
+	case V4L2_CTRL_WHICH_DEF_VAL:
+		xctrl->value = qc.default_value;
+		break;
+	case V4L2_CTRL_WHICH_MIN_VAL:
+		xctrl->value = qc.minimum;
+		break;
+	case V4L2_CTRL_WHICH_MAX_VAL:
+		xctrl->value = qc.maximum;
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	return 0;
 }
 
+static int __uvc_ctrl_get_fixed_compound(struct uvc_video_chain *chain,
+					 struct uvc_control_mapping *mapping,
+					 struct uvc_control *ctrl,
+					 u32 v4l2_which,
+					 struct v4l2_ext_control *xctrl)
+{
+	int ret;
+	u32 flag, id;
+
+	if (mapping->v4l2_type < V4L2_CTRL_COMPOUND_TYPES)
+		return -EINVAL;
+
+	switch (v4l2_which) {
+	case V4L2_CTRL_WHICH_DEF_VAL:
+		flag = UVC_CTRL_FLAG_GET_DEF;
+		id = UVC_CTRL_DATA_DEF;
+		break;
+	case V4L2_CTRL_WHICH_MIN_VAL:
+		flag = UVC_CTRL_FLAG_GET_MIN;
+		id = UVC_CTRL_DATA_MIN;
+		break;
+	case V4L2_CTRL_WHICH_MAX_VAL:
+		flag = UVC_CTRL_FLAG_GET_MAX;
+		id = UVC_CTRL_DATA_MAX;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (!(ctrl->info.flags & flag) && flag != UVC_CTRL_FLAG_GET_DEF)
+		return -EACCES;
+
+	if (!ctrl->cached) {
+		ret = uvc_ctrl_populate_cache(chain, ctrl);
+		if (ret < 0)
+			return ret;
+	}
+
+	return __uvc_ctrl_get_compound_to_user(mapping, ctrl, id, xctrl);
+}
+
 int uvc_ctrl_get_fixed(struct uvc_video_chain *chain,
-		       struct v4l2_ext_control *xctrl)
+		       struct v4l2_ext_control *xctrl, u32 v4l2_which)
 {
 	struct uvc_control *ctrl;
 	struct uvc_control_mapping *mapping;
-	int ret;
 
 	if (__uvc_query_v4l2_class(chain, xctrl->id, 0) >= 0)
 		return -EACCES;
@@ -1950,16 +2003,10 @@ int uvc_ctrl_get_fixed(struct uvc_video_chain *chain,
 		return -EINVAL;
 
 	if (mapping->v4l2_type < V4L2_CTRL_COMPOUND_TYPES)
-		return __uvc_ctrl_get_fixed_std(chain, xctrl);
+		return __uvc_ctrl_get_fixed_std(chain, xctrl, v4l2_which);
 
-	if (!ctrl->cached) {
-		ret = uvc_ctrl_populate_cache(chain, ctrl);
-		if (ret < 0)
-			return ret;
-	}
-
-	return __uvc_ctrl_get_compound_to_user(mapping, ctrl, UVC_CTRL_DATA_DEF,
-					       xctrl);
+	return __uvc_ctrl_get_fixed_compound(chain, mapping, ctrl, v4l2_which,
+					     xctrl);
 }
 
 int __uvc_ctrl_set_compound(struct uvc_control_mapping *mapping,
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index aad61af36271..004e3b764737 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -1043,16 +1043,21 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
 	if (ret < 0)
 		return ret;
 
-	if (ctrls->which == V4L2_CTRL_WHICH_DEF_VAL) {
+	switch (ctrls->which) {
+	case V4L2_CTRL_WHICH_DEF_VAL:
+	case V4L2_CTRL_WHICH_MIN_VAL:
+	case V4L2_CTRL_WHICH_MAX_VAL:
 		for (i = 0; i < ctrls->count; ++ctrl, ++i) {
-			ret = uvc_ctrl_get_fixed(chain, ctrl);
+			ret = uvc_ctrl_get_fixed(chain, ctrl, ctrls->which);
 			if (ret < 0) {
 				ctrls->error_idx = i;
 				return ret;
 			}
 		}
-
 		return 0;
+
+	default:
+		break;
 	}
 
 	ret = uvc_ctrl_begin(chain);
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 9ff95bbad251..54cc47bc2d33 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -913,7 +913,8 @@ static inline int uvc_ctrl_rollback(struct uvc_fh *handle)
 
 int uvc_ctrl_get(struct uvc_video_chain *chain, struct v4l2_ext_control *xctrl);
 int uvc_ctrl_get_fixed(struct uvc_video_chain *chain,
-		       struct v4l2_ext_control *xctrl);
+		       struct v4l2_ext_control *xctrl,
+		       u32 v4l2_which);
 int uvc_ctrl_set(struct uvc_fh *handle, struct v4l2_ext_control *xctrl);
 int uvc_ctrl_is_accessible(struct uvc_video_chain *chain, u32 v4l2_id,
 			   bool read);
-- 
2.37.0.rc0.161.g10f37bed90-goog