Commit 7bc9f038 authored Oct 01, 2017 by Jacob Chen Committed by Mauro Carvalho Chehab Oct 27, 2017

media: i2c: OV5647: ensure clock lane in LP-11 state before streaming on



When I was supporting Rpi Camera Module on the ASUS Tinker board,
I found this driver have some issues with rockchip's mipi-csi driver.
It didn't place clock lane in LP-11 state before performing
D-PHY initialisation.

>From our experience, on some OV sensors,
LP-11 state is not achieved while BIT(5)-0x4800 is cleared.

So let's set BIT(5) and BIT(0) both while not streaming, in order to
coax the clock lane into LP-11 state.

0x4800 : MIPI CTRL 00
	BIT(5) : clock lane gate enable
		0: continuous
		1: none-continuous
	BIT(0) : manually set clock lane
		0: Not used
		1: used

Signed-off-by: Jacob Chen <jacob-chen@iotwrt.com>
Reviewed-by: Luis Oliveira <lolivei@synopsys.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

parent 71862f63

drivers/media/i2c/ov5647.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -253,6 +253,10 @@ static int ov5647_stream_on(struct v4l2_subdev *sd)
		{
		int ret;

		ret = ov5647_write(sd, 0x4800, 0x04);
		if (ret < 0)
		return ret;

		ret = ov5647_write(sd, 0x4202, 0x00);
		if (ret < 0)
		return ret;
		@@ -264,6 +268,10 @@ static int ov5647_stream_off(struct v4l2_subdev *sd)
		{
		int ret;

		ret = ov5647_write(sd, 0x4800, 0x25);
		if (ret < 0)
		return ret;

		ret = ov5647_write(sd, 0x4202, 0x0f);
		if (ret < 0)
		return ret;
		@@ -320,7 +328,10 @@ static int __sensor_init(struct v4l2_subdev *sd)
		return ret;
		}

		return ov5647_write(sd, 0x4800, 0x04);
		/*
		* stream off to make the clock lane into LP-11 state.
		*/
		return ov5647_stream_off(sd);
		}

		static int ov5647_sensor_power(struct v4l2_subdev *sd, int on)