media: rcar-vin: cache video standard

At stream on time the driver should not query the subdevice for which
standard are used. Instead it should be cached when userspace sets the
standard and used at stream on time.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/rcar-vin/rcar-core.c

@@ -96,6 +96,12 @@ static int rvin_digital_subdevice_attach(struct rvin_dev *vin,
 	if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV)
 		return ret;
 
+	/* Read standard */
+	vin->std = V4L2_STD_UNKNOWN;
+	ret = v4l2_subdev_call(subdev, video, g_std, &vin->std);
+	if (ret < 0 && ret != -ENOIOCTLCMD)
+		return ret;
+
 	/* Add the controls */
 	ret = v4l2_ctrl_handler_init(&vin->ctrl_handler, 16);
 	if (ret < 0)

drivers/media/platform/rcar-vin/rcar-dma.c

@@ -592,7 +592,6 @@ void rvin_crop_scale_comp(struct rvin_dev *vin)
 static int rvin_setup(struct rvin_dev *vin)
 {
 	u32 vnmc, dmr, dmr2, interrupts;
-	v4l2_std_id std;
 	bool progressive = false, output_is_yuv = false, input_is_yuv = false;
 
 	switch (vin->format.field) {
@@ -606,10 +605,8 @@ static int rvin_setup(struct rvin_dev *vin)
 		/* Default to TB */
 		vnmc = VNMC_IM_FULL;
 		/* Use BT if video standard can be read and is 60 Hz format */
-		if (!v4l2_subdev_call(vin_to_source(vin), video, g_std, &std)) {
-			if (std & V4L2_STD_525_60)
+		if (vin->std & V4L2_STD_525_60)
 			vnmc = VNMC_IM_FULL | VNMC_FOC;
-		}
 		break;
 	case V4L2_FIELD_INTERLACED_TB:
 		vnmc = VNMC_IM_FULL;

drivers/media/platform/rcar-vin/rcar-v4l2.c

@@ -475,6 +475,8 @@ static int rvin_s_std(struct file *file, void *priv, v4l2_std_id a)
 	if (ret < 0)
 		return ret;
 
+	vin->std = a;
+
 	/* Changing the standard will change the width/height */
 	return rvin_reset_format(vin);
 }
@@ -482,9 +484,13 @@ static int rvin_s_std(struct file *file, void *priv, v4l2_std_id a)
 static int rvin_g_std(struct file *file, void *priv, v4l2_std_id *a)
 {
 	struct rvin_dev *vin = video_drvdata(file);
-	struct v4l2_subdev *sd = vin_to_source(vin);
 
-	return v4l2_subdev_call(sd, video, g_std, a);
+	if (v4l2_subdev_has_op(vin_to_source(vin), pad, dv_timings_cap))
+		return -ENOIOCTLCMD;
+
+	*a = vin->std;
+
+	return 0;
 }
 
 static int rvin_subscribe_event(struct v4l2_fh *fh,

drivers/media/platform/rcar-vin/rcar-vin.h

@@ -118,6 +118,7 @@ struct rvin_info {
  * @crop:		active cropping
  * @compose:		active composing
  * @source:		active size of the video source
+ * @std:		active video standard of the video source
  */
 struct rvin_dev {
 	struct device *dev;
@@ -146,6 +147,7 @@ struct rvin_dev {
 	struct v4l2_rect crop;
 	struct v4l2_rect compose;
 	struct v4l2_rect source;
+	v4l2_std_id std;
 };
 
 #define vin_to_source(vin)		((vin)->digital->subdev)