[PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Eugen Hristev]

Simplify probe function by adding a local variable dev instead of using
&client->dev all the time.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 drivers/media/i2c/imx274.c | 39 ++++++++++++++++++--------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index 25a4ef8f6187..e31f006b10d9 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -1961,23 +1961,23 @@ static int imx274_probe(struct i2c_client *client)
 {
 	struct v4l2_subdev *sd;
 	struct stimx274 *imx274;
+	struct device *dev = &client->dev;
 	int ret;
 
 	/* initialize imx274 */
-	imx274 = devm_kzalloc(&client->dev, sizeof(*imx274), GFP_KERNEL);
+	imx274 = devm_kzalloc(dev, sizeof(*imx274), GFP_KERNEL);
 	if (!imx274)
 		return -ENOMEM;
 
 	mutex_init(&imx274->lock);
 
-	imx274->inck = devm_clk_get_optional(&client->dev, "inck");
+	imx274->inck = devm_clk_get_optional(dev, "inck");
 	if (IS_ERR(imx274->inck))
 		return PTR_ERR(imx274->inck);
 
-	ret = imx274_regulators_get(&client->dev, imx274);
+	ret = imx274_regulators_get(dev, imx274);
 	if (ret) {
-		dev_err(&client->dev,
-			"Failed to get power regulators, err: %d\n", ret);
+		dev_err(dev, "Failed to get power regulators, err: %d\n", ret);
 		return ret;
 	}
 
@@ -1996,7 +1996,7 @@ static int imx274_probe(struct i2c_client *client)
 	/* initialize regmap */
 	imx274->regmap = devm_regmap_init_i2c(client, &imx274_regmap_config);
 	if (IS_ERR(imx274->regmap)) {
-		dev_err(&client->dev,
+		dev_err(dev,
 			"regmap init failed: %ld\n", PTR_ERR(imx274->regmap));
 		ret = -ENODEV;
 		goto err_regmap;
@@ -2013,34 +2013,32 @@ static int imx274_probe(struct i2c_client *client)
 	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
 	ret = media_entity_pads_init(&sd->entity, 1, &imx274->pad);
 	if (ret < 0) {
-		dev_err(&client->dev,
+		dev_err(dev,
 			"%s : media entity init Failed %d\n", __func__, ret);
 		goto err_regmap;
 	}
 
 	/* initialize sensor reset gpio */
-	imx274->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+	imx274->reset_gpio = devm_gpiod_get_optional(dev, "reset",
 						     GPIOD_OUT_HIGH);
 	if (IS_ERR(imx274->reset_gpio)) {
 		if (PTR_ERR(imx274->reset_gpio) != -EPROBE_DEFER)
-			dev_err(&client->dev, "Reset GPIO not setup in DT");
+			dev_err(dev, "Reset GPIO not setup in DT");
 		ret = PTR_ERR(imx274->reset_gpio);
 		goto err_me;
 	}
 
 	/* power on the sensor */
-	ret = imx274_power_on(&client->dev);
+	ret = imx274_power_on(dev);
 	if (ret < 0) {
-		dev_err(&client->dev,
-			"%s : imx274 power on failed\n", __func__);
+		dev_err(dev, "%s : imx274 power on failed\n", __func__);
 		goto err_me;
 	}
 
 	/* initialize controls */
 	ret = v4l2_ctrl_handler_init(&imx274->ctrls.handler, 4);
 	if (ret < 0) {
-		dev_err(&client->dev,
-			"%s : ctrl handler init Failed\n", __func__);
+		dev_err(dev, "%s : ctrl handler init Failed\n", __func__);
 		goto err_power_off;
 	}
 
@@ -2083,23 +2081,22 @@ static int imx274_probe(struct i2c_client *client)
 	/* register subdevice */
 	ret = v4l2_async_register_subdev(sd);
 	if (ret < 0) {
-		dev_err(&client->dev,
-			"%s : v4l2_async_register_subdev failed %d\n",
+		dev_err(dev, "%s : v4l2_async_register_subdev failed %d\n",
 			__func__, ret);
 		goto err_ctrls;
 	}
 
-	pm_runtime_set_active(&client->dev);
-	pm_runtime_enable(&client->dev);
-	pm_runtime_idle(&client->dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+	pm_runtime_idle(dev);
 
-	dev_info(&client->dev, "imx274 : imx274 probe success !\n");
+	dev_info(dev, "imx274 : imx274 probe success !\n");
 	return 0;
 
 err_ctrls:
 	v4l2_ctrl_handler_free(&imx274->ctrls.handler);
 err_power_off:
-	imx274_power_off(&client->dev);
+	imx274_power_off(dev);
 err_me:
 	media_entity_cleanup(&sd->entity);
 err_regmap:
-- 
2.25.1

[PATCH 2/2] media: i2c: imx274: implement fwnode parsing

[Eugen Hristev]

Implement fwnode parsing at probe time.
Check if the bus and number of lanes are supported.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
---
 drivers/media/i2c/imx274.c | 40 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
index e31f006b10d9..774912f44efe 100644
--- a/drivers/media/i2c/imx274.c
+++ b/drivers/media/i2c/imx274.c
@@ -27,6 +27,7 @@
 
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-fwnode.h>
 #include <media/v4l2-subdev.h>
 
 /*
@@ -1957,6 +1958,41 @@ static const struct i2c_device_id imx274_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, imx274_id);
 
+static int imx274_fwnode_parse(struct device *dev)
+{
+	struct fwnode_handle *endpoint;
+	/* Only CSI2 is supported */
+	struct v4l2_fwnode_endpoint ep = {
+		.bus_type = V4L2_MBUS_CSI2_DPHY
+	};
+	int ret;
+
+	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
+	if (!endpoint) {
+		dev_err(dev, "Endpoint node not found\n");
+		return -EINVAL;
+	}
+
+	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
+	fwnode_handle_put(endpoint);
+	if (ret == -ENXIO) {
+		dev_err(dev, "Unsupported bus type, should be CSI2\n");
+		return ret;
+	} else if (ret) {
+		dev_err(dev, "Parsing endpoint node failed %d\n", ret);
+		return ret;
+	}
+
+	/* Check number of data lanes, only 4 lanes supported */
+	if (ep.bus.mipi_csi2.num_data_lanes != 4) {
+		dev_err(dev, "Invalid data lanes: %d\n",
+			ep.bus.mipi_csi2.num_data_lanes);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int imx274_probe(struct i2c_client *client)
 {
 	struct v4l2_subdev *sd;
@@ -1971,6 +2007,10 @@ static int imx274_probe(struct i2c_client *client)
 
 	mutex_init(&imx274->lock);
 
+	ret = imx274_fwnode_parse(dev);
+	if (ret)
+		return ret;
+
 	imx274->inck = devm_clk_get_optional(dev, "inck");
 	if (IS_ERR(imx274->inck))
 		return PTR_ERR(imx274->inck);
-- 
2.25.1

Re: [PATCH 2/2] media: i2c: imx274: implement fwnode parsing

[Sakari Ailus]

Hi Eugen,

On Tue, Nov 23, 2021 at 01:15:21PM +0200, Eugen Hristev wrote:
> Implement fwnode parsing at probe time.
> Check if the bus and number of lanes are supported.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> ---
>  drivers/media/i2c/imx274.c | 40 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
> index e31f006b10d9..774912f44efe 100644
> --- a/drivers/media/i2c/imx274.c
> +++ b/drivers/media/i2c/imx274.c
> @@ -27,6 +27,7 @@
>  
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
> +#include <media/v4l2-fwnode.h>
>  #include <media/v4l2-subdev.h>
>  
>  /*
> @@ -1957,6 +1958,41 @@ static const struct i2c_device_id imx274_id[] = {
>  };
>  MODULE_DEVICE_TABLE(i2c, imx274_id);
>  
> +static int imx274_fwnode_parse(struct device *dev)
> +{
> +	struct fwnode_handle *endpoint;
> +	/* Only CSI2 is supported */
> +	struct v4l2_fwnode_endpoint ep = {
> +		.bus_type = V4L2_MBUS_CSI2_DPHY
> +	};
> +	int ret;
> +
> +	endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
> +	if (!endpoint) {
> +		dev_err(dev, "Endpoint node not found\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);

This allocates memory for the link frequencies. It needs to be released at
some point.

You could also use v4l1_fwnode_endpoint_parse() as the driver doesn't seem
to use link frequencies (albeit it probably should, but that's another
discussion).

> +	fwnode_handle_put(endpoint);
> +	if (ret == -ENXIO) {
> +		dev_err(dev, "Unsupported bus type, should be CSI2\n");
> +		return ret;
> +	} else if (ret) {
> +		dev_err(dev, "Parsing endpoint node failed %d\n", ret);
> +		return ret;
> +	}
> +
> +	/* Check number of data lanes, only 4 lanes supported */
> +	if (ep.bus.mipi_csi2.num_data_lanes != 4) {
> +		dev_err(dev, "Invalid data lanes: %d\n",
> +			ep.bus.mipi_csi2.num_data_lanes);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  static int imx274_probe(struct i2c_client *client)
>  {
>  	struct v4l2_subdev *sd;
> @@ -1971,6 +2007,10 @@ static int imx274_probe(struct i2c_client *client)
>  
>  	mutex_init(&imx274->lock);
>  
> +	ret = imx274_fwnode_parse(dev);
> +	if (ret)
> +		return ret;
> +
>  	imx274->inck = devm_clk_get_optional(dev, "inck");
>  	if (IS_ERR(imx274->inck))
>  		return PTR_ERR(imx274->inck);

-- 
Kind regards,

Sakari Ailus

Re: [PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Sakari Ailus]

Hi Eugen,

On Tue, Nov 23, 2021 at 01:15:20PM +0200, Eugen Hristev wrote:
> Simplify probe function by adding a local variable dev instead of using
> &client->dev all the time.
> 
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>

It's not really wrong to do this, but is it useful?

You can't even unwrap a single line, the lines are just made a little bit
shorter.

-- 
Kind regards,

Sakari Ailus

Re: [PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Eugen.Hristev]

On 11/23/21 1:25 PM, Sakari Ailus wrote:

> Hi Eugen,
> 
> On Tue, Nov 23, 2021 at 01:15:20PM +0200, Eugen Hristev wrote:
>> Simplify probe function by adding a local variable dev instead of using
>> &client->dev all the time.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> 
> It's not really wrong to do this, but is it useful?
> 
> You can't even unwrap a single line, the lines are just made a little bit
> shorter.

Hi,

I think there are a few (18 +, 21 -) ... but the idea was to make the 
probe function a little bit more easy to read.
Up to you if you want to take this patch.

> 
> --
> Kind regards,
> 
> Sakari Ailus
> 

Re: [PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Luca Ceresoli]

Hi,

On 23/11/21 12:25, Sakari Ailus wrote:
> Hi Eugen,
> 
> On Tue, Nov 23, 2021 at 01:15:20PM +0200, Eugen Hristev wrote:
>> Simplify probe function by adding a local variable dev instead of using
>> &client->dev all the time.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> 
> It's not really wrong to do this, but is it useful?
It is of course a matter of personal taste, but I also prefer a short
name in cases such as this where the same member is accessed a lot of
times. To me it makes code simpler to read and even to write.

> You can't even unwrap a single line, the lines are just made a little bit
> shorter.

Let's be fair, he did unwrap 4. :)

As said, it is a matter of taste so I'll be OK it this patch is dropped.
But since I like it and it looks correct:

Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>

-- 
Luca

Re: [PATCH 2/2] media: i2c: imx274: implement fwnode parsing

[Eugen.Hristev]

On 11/23/21 1:23 PM, Sakari Ailus wrote:
> Hi Eugen,
> 
> On Tue, Nov 23, 2021 at 01:15:21PM +0200, Eugen Hristev wrote:
>> Implement fwnode parsing at probe time.
>> Check if the bus and number of lanes are supported.
>>
>> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
>> ---
>>   drivers/media/i2c/imx274.c | 40 ++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 40 insertions(+)
>>
>> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
>> index e31f006b10d9..774912f44efe 100644
>> --- a/drivers/media/i2c/imx274.c
>> +++ b/drivers/media/i2c/imx274.c
>> @@ -27,6 +27,7 @@
>>
>>   #include <media/v4l2-ctrls.h>
>>   #include <media/v4l2-device.h>
>> +#include <media/v4l2-fwnode.h>
>>   #include <media/v4l2-subdev.h>
>>
>>   /*
>> @@ -1957,6 +1958,41 @@ static const struct i2c_device_id imx274_id[] = {
>>   };
>>   MODULE_DEVICE_TABLE(i2c, imx274_id);
>>
>> +static int imx274_fwnode_parse(struct device *dev)
>> +{
>> +     struct fwnode_handle *endpoint;
>> +     /* Only CSI2 is supported */
>> +     struct v4l2_fwnode_endpoint ep = {
>> +             .bus_type = V4L2_MBUS_CSI2_DPHY
>> +     };
>> +     int ret;
>> +
>> +     endpoint = fwnode_graph_get_next_endpoint(dev_fwnode(dev), NULL);
>> +     if (!endpoint) {
>> +             dev_err(dev, "Endpoint node not found\n");
>> +             return -EINVAL;
>> +     }
>> +
>> +     ret = v4l2_fwnode_endpoint_alloc_parse(endpoint, &ep);
> 
> This allocates memory for the link frequencies. It needs to be released at
> some point.
> 
> You could also use v4l1_fwnode_endpoint_parse() as the driver doesn't seem
> to use link frequencies (albeit it probably should, but that's another
> discussion).

Okay, got it, I am changing, testing and resending.

Thanks

> 
>> +     fwnode_handle_put(endpoint);
>> +     if (ret == -ENXIO) {
>> +             dev_err(dev, "Unsupported bus type, should be CSI2\n");
>> +             return ret;
>> +     } else if (ret) {
>> +             dev_err(dev, "Parsing endpoint node failed %d\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     /* Check number of data lanes, only 4 lanes supported */
>> +     if (ep.bus.mipi_csi2.num_data_lanes != 4) {
>> +             dev_err(dev, "Invalid data lanes: %d\n",
>> +                     ep.bus.mipi_csi2.num_data_lanes);
>> +             return -EINVAL;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>>   static int imx274_probe(struct i2c_client *client)
>>   {
>>        struct v4l2_subdev *sd;
>> @@ -1971,6 +2007,10 @@ static int imx274_probe(struct i2c_client *client)
>>
>>        mutex_init(&imx274->lock);
>>
>> +     ret = imx274_fwnode_parse(dev);
>> +     if (ret)
>> +             return ret;
>> +
>>        imx274->inck = devm_clk_get_optional(dev, "inck");
>>        if (IS_ERR(imx274->inck))
>>                return PTR_ERR(imx274->inck);
> 
> --
> Kind regards,
> 
> Sakari Ailus
> 

Re: [PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Sakari Ailus]

Hi Luca,

On Tue, Nov 23, 2021 at 12:35:42PM +0100, Luca Ceresoli wrote:
> Hi,
> 
> On 23/11/21 12:25, Sakari Ailus wrote:
> > Hi Eugen,
> > 
> > On Tue, Nov 23, 2021 at 01:15:20PM +0200, Eugen Hristev wrote:
> >> Simplify probe function by adding a local variable dev instead of using
> >> &client->dev all the time.
> >>
> >> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> > 
> > It's not really wrong to do this, but is it useful?
> It is of course a matter of personal taste, but I also prefer a short
> name in cases such as this where the same member is accessed a lot of
> times. To me it makes code simpler to read and even to write.
> 
> > You can't even unwrap a single line, the lines are just made a little bit
> > shorter.
> 
> Let's be fair, he did unwrap 4. :)

Ah, yes, you're right.

But at least one could have been wrapped without the change. :-)

> 
> As said, it is a matter of taste so I'll be OK it this patch is dropped.
> But since I like it and it looks correct:
> 
> Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>

-- 
Sakari Ailus

Re: [PATCH 1/2] media: i2c: imx274: simplify probe function by adding local variable dev

[Sakari Ailus]

On Tue, Nov 23, 2021 at 11:35:33AM +0000, Eugen.Hristev@microchip.com wrote:
> On 11/23/21 1:25 PM, Sakari Ailus wrote:
> 
> > Hi Eugen,
> > 
> > On Tue, Nov 23, 2021 at 01:15:20PM +0200, Eugen Hristev wrote:
> >> Simplify probe function by adding a local variable dev instead of using
> >> &client->dev all the time.
> >>
> >> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> > 
> > It's not really wrong to do this, but is it useful?
> > 
> > You can't even unwrap a single line, the lines are just made a little bit
> > shorter.
> 
> Hi,
> 
> I think there are a few (18 +, 21 -) ... but the idea was to make the 

Indeed you're right.

> probe function a little bit more easy to read.
> Up to you if you want to take this patch.

I'll take it.

-- 
Sakari Ailus