[v3,2/2] v4l: mt9v032: Add OF support

Parse DT properties into a platform data structure when a DT node is
available.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

---

Changes since v2:

- Use of_graph_get_next_endpoint()

Changes since v1:

- Add MT9V02[24] compatible strings
- Prefix all compatible strings with "aptina,"
- Use "link-frequencies" instead of "link-freqs"

Open questions:

- Should the color/monochrome model be inferred from the compatible string, or
  should a separate DT property be used for that ?

---
 .../devicetree/bindings/media/i2c/mt9v032.txt      | 45 ++++++++++++++
 MAINTAINERS                                        |  1 +
 drivers/media/i2c/mt9v032.c                        | 70 +++++++++++++++++++++-
 3 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/mt9v032.txt

Hi Laurent,

On Sat, Mar 14, 2015 at 04:57:37PM +0200, Laurent Pinchart wrote:
...
> diff --git a/Documentation/devicetree/bindings/media/i2c/mt9v032.txt b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt
> new file mode 100644
> index 0000000..68b134e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt
> @@ -0,0 +1,45 @@
> +* Aptina 1/3-Inch WVGA CMOS Digital Image Sensor
> +
> +The Aptina MT9V032 is a 1/3-inch CMOS active pixel digital image sensor with
> +an active array size of 752H x 480V. It is programmable through a simple
> +two-wire serial interface.
> +
> +Required Properties:
> +
> +- compatible: value should be either one among the following
> +	(a) "aptina,mt9v022" for MT9V022 color sensor
> +	(b) "aptina,mt9v022m" for MT9V022 monochrome sensor
> +	(c) "aptina,mt9v024" for MT9V024 color sensor
> +	(d) "aptina,mt9v024m" for MT9V024 monochrome sensor
> +	(e) "aptina,mt9v032" for MT9V032 color sensor
> +	(f) "aptina,mt9v032m" for MT9V032 monochrome sensor
> +	(g) "aptina,mt9v034" for MT9V034 color sensor
> +	(h) "aptina,mt9v034m" for MT9V034 monochrome sensor
> +
> +Optional Properties:
> +
> +- link-frequencies: List of allowed link frequencies in Hz. Each frequency is
> +	expressed as a 64-bit big-endian integer.
> +
> +For further reading on port node refer to
> +Documentation/devicetree/bindings/media/video-interfaces.txt.
> +
> +Example:
> +
> +	i2c0@1c22000 {
> +		...
> +		...
> +		mt9v032@5c {
> +			compatible = "aptina,mt9v032";
> +			reg = <0x5c>;
> +
> +			port {
> +				mt9v032_1: endpoint {
> +					link-frequencies =
> +						<0 13000000>, <0 26600000>,

How about:

/bits/ 64 <13000000> ...

> +						<0 27000000>;
> +				};
> +			};
> +		};
> +		...
> +	};
> diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
> index 255ea91..139eeef 100644
> --- a/drivers/media/i2c/mt9v032.c
> +++ b/drivers/media/i2c/mt9v032.c
> @@ -17,6 +17,8 @@
>  #include <linux/i2c.h>
>  #include <linux/log2.h>
>  #include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
>  #include <linux/regmap.h>
>  #include <linux/slab.h>
>  #include <linux/videodev2.h>
> @@ -26,6 +28,7 @@
>  #include <media/mt9v032.h>
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
> +#include <media/v4l2-of.h>
>  #include <media/v4l2-subdev.h>
>  
>  /* The first four rows are black rows. The active area spans 753x481 pixels. */
> @@ -876,10 +879,59 @@ static const struct regmap_config mt9v032_regmap_config = {
>   * Driver initialization and probing
>   */
>  
> +static struct mt9v032_platform_data *
> +mt9v032_get_pdata(struct i2c_client *client)
> +{
> +	struct mt9v032_platform_data *pdata;
> +	struct v4l2_of_endpoint endpoint;
> +	struct device_node *np;
> +	struct property *prop;
> +
> +	if (!IS_ENABLED(CONFIG_OF) || !client->dev.of_node)
> +		return client->dev.platform_data;
> +
> +	np = of_graph_get_next_endpoint(client->dev.of_node, NULL);
> +	if (!np)
> +		return NULL;
> +
> +	if (v4l2_of_parse_endpoint(np, &endpoint) < 0)
> +		goto done;
> +
> +	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata)
> +		goto done;
> +
> +	prop = of_find_property(np, "link-frequencies", NULL);
> +	if (prop) {
> +		size_t size = prop->length / 8;
> +		u64 *link_freqs;
> +
> +		link_freqs = devm_kzalloc(&client->dev,
> +					  size * sizeof(*link_freqs),

You could simply use prop->length here. I think that'd look nicer.

> +					  GFP_KERNEL);
> +		if (!link_freqs)
> +			goto done;
> +
> +		if (of_property_read_u64_array(np, "link-frequencies",
> +					       link_freqs, size) < 0)
> +			goto done;
> +
> +		pdata->link_freqs = link_freqs;
> +		pdata->link_def_freq = link_freqs[0];
> +	}
> +
> +	pdata->clk_pol = !!(endpoint.bus.parallel.flags &
> +			    V4L2_MBUS_PCLK_SAMPLE_RISING);
> +
> +done:
> +	of_node_put(np);
> +	return pdata;
> +}
> +
>  static int mt9v032_probe(struct i2c_client *client,
>  		const struct i2c_device_id *did)
>  {
> -	struct mt9v032_platform_data *pdata = client->dev.platform_data;
> +	struct mt9v032_platform_data *pdata = mt9v032_get_pdata(client);
>  	struct mt9v032 *mt9v032;
>  	unsigned int i;
>  	int ret;
> @@ -1037,9 +1089,25 @@ static const struct i2c_device_id mt9v032_id[] = {
>  };
>  MODULE_DEVICE_TABLE(i2c, mt9v032_id);
>  
> +#if IS_ENABLED(CONFIG_OF)
> +static const struct of_device_id mt9v032_of_match[] = {
> +	{ .compatible = "aptina,mt9v022" },
> +	{ .compatible = "aptina,mt9v022m" },
> +	{ .compatible = "aptina,mt9v024" },
> +	{ .compatible = "aptina,mt9v024m" },
> +	{ .compatible = "aptina,mt9v032" },
> +	{ .compatible = "aptina,mt9v032m" },
> +	{ .compatible = "aptina,mt9v034" },
> +	{ .compatible = "aptina,mt9v034m" },
> +	{ /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, mt9v032_of_match);
> +#endif
> +
>  static struct i2c_driver mt9v032_driver = {
>  	.driver = {
>  		.name = "mt9v032",
> +		.of_match_table = of_match_ptr(mt9v032_of_match),
>  	},
>  	.probe		= mt9v032_probe,
>  	.remove		= mt9v032_remove,

Hi Sakari,

On Sunday 15 March 2015 02:21:07 Sakari Ailus wrote:
> On Sat, Mar 14, 2015 at 04:57:37PM +0200, Laurent Pinchart wrote:
> ...
> 
> > diff --git a/Documentation/devicetree/bindings/media/i2c/mt9v032.txt
> > b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt new file mode
> > 100644
> > index 0000000..68b134e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/mt9v032.txt
> > @@ -0,0 +1,45 @@
> > +* Aptina 1/3-Inch WVGA CMOS Digital Image Sensor
> > +
> > +The Aptina MT9V032 is a 1/3-inch CMOS active pixel digital image sensor
> > with +an active array size of 752H x 480V. It is programmable through a
> > simple +two-wire serial interface.
> > +
> > +Required Properties:
> > +
> > +- compatible: value should be either one among the following
> > +	(a) "aptina,mt9v022" for MT9V022 color sensor
> > +	(b) "aptina,mt9v022m" for MT9V022 monochrome sensor
> > +	(c) "aptina,mt9v024" for MT9V024 color sensor
> > +	(d) "aptina,mt9v024m" for MT9V024 monochrome sensor
> > +	(e) "aptina,mt9v032" for MT9V032 color sensor
> > +	(f) "aptina,mt9v032m" for MT9V032 monochrome sensor
> > +	(g) "aptina,mt9v034" for MT9V034 color sensor
> > +	(h) "aptina,mt9v034m" for MT9V034 monochrome sensor
> > +
> > +Optional Properties:
> > +
> > +- link-frequencies: List of allowed link frequencies in Hz. Each
> > frequency is +	expressed as a 64-bit big-endian integer.
> > +
> > +For further reading on port node refer to
> > +Documentation/devicetree/bindings/media/video-interfaces.txt.
> > +
> > +Example:
> > +
> > +	i2c0@1c22000 {
> > +		...
> > +		...
> > +		mt9v032@5c {
> > +			compatible = "aptina,mt9v032";
> > +			reg = <0x5c>;
> > +
> > +			port {
> > +				mt9v032_1: endpoint {
> > +					link-frequencies =
> > +						<0 13000000>, <0 26600000>,
> 
> How about:
> 
> /bits/ 64 <13000000> ...

Absolutely.

> > +						<0 27000000>;
> > +				};
> > +			};
> > +		};
> > +		...
> > +	};
> > diff --git a/drivers/media/i2c/mt9v032.c b/drivers/media/i2c/mt9v032.c
> > index 255ea91..139eeef 100644
> > --- a/drivers/media/i2c/mt9v032.c
> > +++ b/drivers/media/i2c/mt9v032.c

[snip]

> > @@ -876,10 +879,59 @@ static const struct regmap_config
> > mt9v032_regmap_config = {> 
> >   * Driver initialization and probing
> >   */
> > 
> > +static struct mt9v032_platform_data *
> > +mt9v032_get_pdata(struct i2c_client *client)
> > +{
> > +	struct mt9v032_platform_data *pdata;
> > +	struct v4l2_of_endpoint endpoint;
> > +	struct device_node *np;
> > +	struct property *prop;
> > +
> > +	if (!IS_ENABLED(CONFIG_OF) || !client->dev.of_node)
> > +		return client->dev.platform_data;
> > +
> > +	np = of_graph_get_next_endpoint(client->dev.of_node, NULL);
> > +	if (!np)
> > +		return NULL;
> > +
> > +	if (v4l2_of_parse_endpoint(np, &endpoint) < 0)
> > +		goto done;
> > +
> > +	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
> > +	if (!pdata)
> > +		goto done;
> > +
> > +	prop = of_find_property(np, "link-frequencies", NULL);
> > +	if (prop) {
> > +		size_t size = prop->length / 8;
> > +		u64 *link_freqs;
> > +
> > +		link_freqs = devm_kzalloc(&client->dev,
> > +					  size * sizeof(*link_freqs),
> 
> You could simply use prop->length here. I think that'd look nicer.

How about devm_kcalloc(&client->dev, size, sizeof(*link_freqs)) as this is 
allocating an array ?

> > +					  GFP_KERNEL);
> > +		if (!link_freqs)
> > +			goto done;
> > +
> > +		if (of_property_read_u64_array(np, "link-frequencies",
> > +					       link_freqs, size) < 0)
> > +			goto done;
> > +
> > +		pdata->link_freqs = link_freqs;
> > +		pdata->link_def_freq = link_freqs[0];
> > +	}
> > +
> > +	pdata->clk_pol = !!(endpoint.bus.parallel.flags &
> > +			    V4L2_MBUS_PCLK_SAMPLE_RISING);
> > +
> > +done:
> > +	of_node_put(np);
> > +	return pdata;
> > +}

Hi Laurent,

On Wed, Mar 18, 2015 at 03:32:28PM +0200, Laurent Pinchart wrote:
...
> > > @@ -876,10 +879,59 @@ static const struct regmap_config
> > > mt9v032_regmap_config = {> 
> > >   * Driver initialization and probing
> > >   */
> > > 
> > > +static struct mt9v032_platform_data *
> > > +mt9v032_get_pdata(struct i2c_client *client)
> > > +{
> > > +	struct mt9v032_platform_data *pdata;
> > > +	struct v4l2_of_endpoint endpoint;
> > > +	struct device_node *np;
> > > +	struct property *prop;
> > > +
> > > +	if (!IS_ENABLED(CONFIG_OF) || !client->dev.of_node)
> > > +		return client->dev.platform_data;
> > > +
> > > +	np = of_graph_get_next_endpoint(client->dev.of_node, NULL);
> > > +	if (!np)
> > > +		return NULL;
> > > +
> > > +	if (v4l2_of_parse_endpoint(np, &endpoint) < 0)
> > > +		goto done;
> > > +
> > > +	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
> > > +	if (!pdata)
> > > +		goto done;
> > > +
> > > +	prop = of_find_property(np, "link-frequencies", NULL);
> > > +	if (prop) {
> > > +		size_t size = prop->length / 8;
> > > +		u64 *link_freqs;
> > > +
> > > +		link_freqs = devm_kzalloc(&client->dev,
> > > +					  size * sizeof(*link_freqs),
> > 
> > You could simply use prop->length here. I think that'd look nicer.
> 
> How about devm_kcalloc(&client->dev, size, sizeof(*link_freqs)) as this is 
> allocating an array ?

That's certainly fine as well, I think. Feel free to divide prop->length by
sizeof(*link_freqs) instead of plain 8.