<html><head><meta name="color-scheme" content="light dark"></head><body><pre style="word-wrap: break-word; white-space: pre-wrap;">From 0fec1c81707f5335d0b04b5e97d2ddd0b902377b Mon Sep 17 00:00:00 2001
From: Lad Prabhakar &lt;prabhakar.mahadev-lad.rj@bp.renesas.com&gt;
Date: Tue, 10 Mar 2020 14:17:07 +0100
Subject: [PATCH] media: i2c: imx219: Fix power sequence

Commit ca45448a56659c6df6e0436188e97f6cc65dea8a upstream.

When supporting Rpi Camera v2 Module on the RZ/G2E, found the driver had
some issues with rcar mipi-csi driver. The sensor never entered into LP-11
state.

The powerup sequence in the datasheet[1] shows the sensor entering into
LP-11 in streaming mode, so to fix this issue transitions are performed
from "streaming -&gt; standby" in the probe() after power up.

With this commit the sensor is able to enter LP-11 mode during power up,
as expected by some CSI-2 controllers.

[1] https://publiclab.org/system/images/photos/000/023/294/original/
RASPBERRY_PI_CAMERA_V2_DATASHEET_IMX219PQH5_7.0.0_Datasheet_XXX.PDF

Signed-off-by: Lad Prabhakar &lt;prabhakar.mahadev-lad.rj@bp.renesas.com&gt;
Acked-by: Dave Stevenson &lt;dave.stevenson@raspberrypi.com&gt;
Signed-off-by: Sakari Ailus &lt;sakari.ailus@linux.intel.com&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab+huawei@kernel.org&gt;
---
 drivers/media/i2c/imx219.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

--- a/drivers/media/i2c/imx219.c
+++ b/drivers/media/i2c/imx219.c
@@ -1224,6 +1224,23 @@ static int imx219_probe(struct i2c_clien
 	/* Set default mode to max resolution */
 	imx219-&gt;mode = &amp;supported_modes[0];
 
+	/* sensor doesn't enter LP-11 state upon power up until and unless
+	 * streaming is started, so upon power up switch the modes to:
+	 * streaming -&gt; standby
+	 */
+	ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
+			       IMX219_REG_VALUE_08BIT, IMX219_MODE_STREAMING);
+	if (ret &lt; 0)
+		goto error_power_off;
+	usleep_range(100, 110);
+
+	/* put sensor back to standby mode */
+	ret = imx219_write_reg(imx219, IMX219_REG_MODE_SELECT,
+			       IMX219_REG_VALUE_08BIT, IMX219_MODE_STANDBY);
+	if (ret &lt; 0)
+		goto error_power_off;
+	usleep_range(100, 110);
+
 	ret = imx219_init_controls(imx219);
 	if (ret)
 		goto error_power_off;
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