Re: [PATCH 4/5] media: mt9p031: Make pixel clock polarity configurable by DT

From: Stefan Riedmüller
Date: Wed Sep 30 2020 - 03:58:07 EST


Hi Sakari,

thanks for your review.

On 25.09.20 22:07, Sakari Ailus wrote:
Hi Stefan,

Thanks for the patchset.

On Fri, Sep 25, 2020 at 09:50:28AM +0200, Stefan Riedmueller wrote:
From: Christian Hemp <c.hemp@xxxxxxxxx>

Evaluate the desired pixel clock polarity from the device tree.

Signed-off-by: Christian Hemp <c.hemp@xxxxxxxxx>
Signed-off-by: Stefan Riedmueller <s.riedmueller@xxxxxxxxx>
---
drivers/media/i2c/Kconfig | 1 +
drivers/media/i2c/mt9p031.c | 19 ++++++++++++++++++-
include/media/i2c/mt9p031.h | 1 +
3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig
index c7ba76fee599..7c026daeacf0 100644
--- a/drivers/media/i2c/Kconfig
+++ b/drivers/media/i2c/Kconfig
@@ -1103,6 +1103,7 @@ config VIDEO_MT9P031
select MEDIA_CONTROLLER
select VIDEO_V4L2_SUBDEV_API
select VIDEO_APTINA_PLL
+ select V4L2_FWNODE
help
This is a Video4Linux2 sensor driver for the Aptina
(Micron) mt9p031 5 Mpixel camera.
diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index f5d6a7890c47..8f8ee37a2dd2 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -27,6 +27,7 @@
#include <media/v4l2-async.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
#include <media/v4l2-subdev.h>
#include "aptina-pll.h"
@@ -399,6 +400,14 @@ static int __mt9p031_set_power(struct mt9p031 *mt9p031, bool on)
return ret;
}
+ /* Configure the pixel clock polarity */
+ if (mt9p031->pdata && mt9p031->pdata->pixclk_pol) {
+ ret = mt9p031_write(client, MT9P031_PIXEL_CLOCK_CONTROL,
+ MT9P031_PIXEL_CLOCK_INVERT);
+ if (ret < 0)
+ return ret;
+ }
+
return v4l2_ctrl_handler_setup(&mt9p031->ctrls);
}
@@ -1062,7 +1071,8 @@ static const struct v4l2_subdev_internal_ops mt9p031_subdev_internal_ops = {
static struct mt9p031_platform_data *
mt9p031_get_pdata(struct i2c_client *client)
{
- struct mt9p031_platform_data *pdata;
+ struct mt9p031_platform_data *pdata = NULL;
+ struct v4l2_fwnode_endpoint endpoint;

Could you initialise the bus_type field to a valid value? I suppose this
sensor only supports one of them? That way you'll also initialise the rest
of the struct fields to zero.

Yes, I'll do that and send a v2.

Thanks,
Stefan


struct device_node *np;
if (!IS_ENABLED(CONFIG_OF) || !client->dev.of_node)
@@ -1072,6 +1082,10 @@ mt9p031_get_pdata(struct i2c_client *client)
if (!np)
return NULL;
+ endpoint.bus_type = V4L2_MBUS_UNKNOWN;
+ if (v4l2_fwnode_endpoint_parse(of_fwnode_handle(np), &endpoint) < 0)
+ goto done;
+
pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
goto done;
@@ -1079,6 +1093,9 @@ mt9p031_get_pdata(struct i2c_client *client)
of_property_read_u32(np, "input-clock-frequency", &pdata->ext_freq);
of_property_read_u32(np, "pixel-clock-frequency", &pdata->target_freq);
+ pdata->pixclk_pol = !!(endpoint.bus.parallel.flags &
+ V4L2_MBUS_PCLK_SAMPLE_RISING);
+
done:
of_node_put(np);
return pdata;
diff --git a/include/media/i2c/mt9p031.h b/include/media/i2c/mt9p031.h
index 7c29c53aa988..f933cd0be8e5 100644
--- a/include/media/i2c/mt9p031.h
+++ b/include/media/i2c/mt9p031.h
@@ -10,6 +10,7 @@ struct v4l2_subdev;
* @target_freq: Pixel clock frequency
*/
struct mt9p031_platform_data {
+ unsigned int pixclk_pol:1;
int ext_freq;
int target_freq;
};