From: Stefan Riedmueller <s.riedmueller@phytec.de>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
Sakari Ailus <sakari.ailus@linux.intel.com>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
Dirk Bender <d.bender@phytec.de>,
Stefan Riedmueller <s.riedmueller@phytec.de>
Subject: [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream
Date: Wed, 30 Sep 2020 12:51:33 +0200 [thread overview]
Message-ID: <20200930105133.139981-5-s.riedmueller@phytec.de> (raw)
In-Reply-To: <20200930105133.139981-1-s.riedmueller@phytec.de>
From: Dirk Bender <d.bender@phytec.de>
To prevent corrupted frames after starting and stopping the sensor it's
datasheet specifies a specific pause sequence to follow:
Stopping:
Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off
Restarting:
Set Chip_Enable On -> Clear Pause_Restart Bit
The Restart Bit is cleared automatically and must not be cleared
manually as this would cause undefined behavior.
Signed-off-by: Dirk Bender <d.bender@phytec.de>
Signed-off-by: Stefan Riedmueller <s.riedmueller@phytec.de>
---
No changes in v2
---
drivers/media/i2c/mt9p031.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index d10457361e6c..d59f66e3dcf3 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -80,6 +80,8 @@
#define MT9P031_PIXEL_CLOCK_SHIFT(n) ((n) << 8)
#define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0)
#define MT9P031_FRAME_RESTART 0x0b
+#define MT9P031_FRAME_RESTART_SET (1 << 0)
+#define MT9P031_FRAME_PAUSE_RESTART_SET (1 << 1)
#define MT9P031_SHUTTER_DELAY 0x0c
#define MT9P031_RST 0x0d
#define MT9P031_RST_ENABLE 1
@@ -483,9 +485,25 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031)
static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable)
{
struct mt9p031 *mt9p031 = to_mt9p031(subdev);
+ struct i2c_client *client = v4l2_get_subdevdata(subdev);
+ int val;
int ret;
if (!enable) {
+ val = mt9p031_read(client, MT9P031_FRAME_RESTART);
+
+ /* enable pause restart */
+ val |= MT9P031_FRAME_PAUSE_RESTART_SET;
+ ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val);
+ if (ret < 0)
+ return ret;
+
+ /* enable restart + keep pause restart set */
+ val |= MT9P031_FRAME_RESTART_SET;
+ ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val);
+ if (ret < 0)
+ return ret;
+
/* Stop sensor readout */
ret = mt9p031_set_output_control(mt9p031,
MT9P031_OUTPUT_CONTROL_CEN, 0);
@@ -505,6 +523,13 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable)
if (ret < 0)
return ret;
+ val = mt9p031_read(client, MT9P031_FRAME_RESTART);
+ /* disable reset + pause restart */
+ val &= ~MT9P031_FRAME_PAUSE_RESTART_SET;
+ ret = mt9p031_write(client, MT9P031_FRAME_RESTART, val);
+ if (ret < 0)
+ return ret;
+
return mt9p031_pll_enable(mt9p031);
}
--
2.25.1
next prev parent reply other threads:[~2020-09-30 10:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-30 10:51 [PATCH v2 1/5] media: mt9p031: Add support for 8 bit and 10 bit formats Stefan Riedmueller
2020-09-30 10:51 ` [PATCH v2 2/5] media: mt9p031: Read back the real clock rate Stefan Riedmueller
2020-10-01 23:56 ` Laurent Pinchart
2020-09-30 10:51 ` [PATCH v2 3/5] media: mt9p031: Implement [gs]_register debug calls Stefan Riedmueller
2020-09-30 11:38 ` Laurent Pinchart
2020-10-01 8:56 ` Stefan Riedmüller
2020-10-02 0:06 ` Laurent Pinchart
2020-10-05 9:33 ` Stefan Riedmüller
2020-09-30 10:51 ` [PATCH v2 4/5] media: mt9p031: Make pixel clock polarity configurable by DT Stefan Riedmueller
2020-10-01 16:10 ` Sakari Ailus
2020-10-01 16:11 ` Sakari Ailus
2020-10-05 8:52 ` Stefan Riedmüller
2020-09-30 10:51 ` Stefan Riedmueller [this message]
2020-10-02 0:05 ` [PATCH v2 5/5] media: mt9p031: Fix corrupted frame after restarting stream Laurent Pinchart
2020-10-05 9:28 ` Stefan Riedmüller
2020-10-05 13:08 ` Laurent Pinchart
2020-10-14 7:14 ` Stefan Riedmüller
2020-09-30 11:42 ` [PATCH v2 1/5] media: mt9p031: Add support for 8 bit and 10 bit formats Laurent Pinchart
2020-10-01 9:07 ` Stefan Riedmüller
2020-10-01 23:53 ` Laurent Pinchart
2020-10-05 9:31 ` Stefan Riedmüller
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