[PATCH 20/25] media: ov5647: Program mode only if it has changed

[Jacopo Mondi <jacopo@jmondi.org>]

Store in the driver structure a pointer to the currently applied mode
and program a new one at s_stream(1) time only if it has changed.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
---
 drivers/media/i2c/ov5647.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
index 39e320f321bd8..ac114269e1c73 100644
--- a/drivers/media/i2c/ov5647.c
+++ b/drivers/media/i2c/ov5647.c
@@ -96,6 +96,7 @@ struct ov5647 {
 	bool				clock_ncont;
 	struct v4l2_ctrl_handler	ctrls;
 	struct ov5647_mode		*mode;
+	struct ov5647_mode		*current_mode;
 };
 
 static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
@@ -750,9 +751,13 @@ static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
 static int ov5647_set_mode(struct v4l2_subdev *sd)
 {
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	struct ov5647 *sensor = to_sensor(sd);
 	u8 resetval, rdval;
 	int ret;
 
+	if (sensor->mode == sensor->current_mode)
+		return 0;
+
 	ret = ov5647_read(sd, OV5647_SW_STANDBY, &rdval);
 	if (ret < 0)
 		return ret;
@@ -778,6 +783,8 @@ static int ov5647_set_mode(struct v4l2_subdev *sd)
 			return ret;
 	}
 
+	sensor->current_mode = sensor->mode;
+
 	return 0;
 }
 
@@ -816,6 +823,7 @@ static int ov5647_stream_on(struct v4l2_subdev *sd)
 
 static int ov5647_stream_off(struct v4l2_subdev *sd)
 {
+	struct ov5647 *sensor = to_sensor(sd);
 	int ret;
 
 	ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, MIPI_CTRL00_CLOCK_LANE_GATE |
@@ -827,7 +835,13 @@ static int ov5647_stream_off(struct v4l2_subdev *sd)
 	if (ret < 0)
 		return ret;
 
-	return ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
+	ret = ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
+	if (ret < 0)
+		return ret;
+
+	sensor->current_mode = NULL;
+
+	return 0;
 }
 
 static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
-- 
2.27.0