Re: [PATCH] media: i2c: tvp514x: add OF support

[Prabhakar Lad <prabhakar.csengg@gmail.com>]

Hi Laurent,

Thanks for the review.

On Mon, Apr 29, 2013 at 7:27 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> Hi Prabhakar,
>
> Thank you for the patch. Please see below for a couple of comments. Most of
> them apply to your adv7343 patch as well.
>
alright I'll fix for that patch as well.

> On Friday 26 April 2013 16:53:50 Prabhakar Lad wrote:
>> From: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>>
>> add OF support for the tvp514x driver.
>>
>> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
>> Cc: Hans Verkuil <hans.verkuil@cisco.com>
>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
>> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
>> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
>> Cc: Sakari Ailus <sakari.ailus@iki.fi>
>> Cc: Grant Likely <grant.likely@secretlab.ca>
>> Cc: Rob Herring <rob.herring@calxeda.com>
>> Cc: Rob Landley <rob@landley.net>
>> Cc: devicetree-discuss@lists.ozlabs.org
>> Cc: linux-doc@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: davinci-linux-open-source@linux.davincidsp.com
>> ---
>>  RFC v1: https://patchwork.kernel.org/patch/2030061/
>>  RFC v2: https://patchwork.kernel.org/patch/2061811/
>>
>>  Changes for current version from RFC v2:
>>  1: Fixed review comments pointed by Sylwester.
>>
>>  .../devicetree/bindings/media/i2c/tvp514x.txt      |   38 +++++++++++
>>  drivers/media/i2c/tvp514x.c                        |   67 +++++++++++++++--
>>  2 files changed, 98 insertions(+), 7 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/media/i2c/tvp514x.txt
>>
>> diff --git a/Documentation/devicetree/bindings/media/i2c/tvp514x.txt
>> b/Documentation/devicetree/bindings/media/i2c/tvp514x.txt new file mode
>> 100644
>> index 0000000..618640a
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/media/i2c/tvp514x.txt
>> @@ -0,0 +1,38 @@
>> +* Texas Instruments TVP514x video decoder
>> +
>> +The TVP5146/TVP5146m2/TVP5147/TVP5147m1 device is high quality, single-chip
>> +digital video decoder that digitizes and decodes all popular baseband
>> +analog video formats into digital video component. The tvp514x decoder
>> +supports analog-to-digital (A/D) conversion of component RGB and YPbPr
>> +signals as well as A/D conversion and decoding of NTSC, PAL and SECAM
>> +composite and S-video into component YCbCr.
>> +
>> +Required Properties :
>> +- compatible: Must be "ti,tvp514x-decoder"
>
> According to the code below, it must be one of
>
>         "ti,tvp5146-decoder"
>         "ti,tvp5146m2-decoder"
>         "ti,tvp5147-decoder"
>         "ti,tvp5147m1-decoder"
>
> Couldn't you remove "-decoder" ?
>
yeah I missed to mention other compatible options, 'll remove
"-decoder" as well.

> You should add a reference to the V4L2 DT bindings documentation to explain
> what the port and endpoint nodes are for.
>
OK

>> +- hsync-active: HSYNC Polarity configuration for current interface.
>> +- vsync-active: VSYNC Polarity configuration for current interface.
>> +- pclk-sample: Clock polarity of the current interface.
>
> s/current interface/endpoint/ ?
>
yeah endpoint.

>> +Example:
>> +
>> +i2c0@1c22000 {
>> +     ...
>> +     ...
>> +
>> +     tvp514x@5c {
>> +             compatible = "ti,tvp514x-decoder";
>> +             reg = <0x5c>;
>> +
>> +             port {
>> +                     tvp514x_1: endpoint {
>> +                             /* Active high (Defaults to 0) */
>> +                             hsync-active = <1>;
>> +                             /* Active high (Defaults to 0) */
>> +                             vsync-active = <1>;
>> +                             /* Active low (Defaults to 0) */
>> +                             pclk-sample = <0>;
>> +                     };
>> +             };
>> +     };
>> +     ...
>> +};
>> diff --git a/drivers/media/i2c/tvp514x.c b/drivers/media/i2c/tvp514x.c
>> index 887bd93..d37b85e 100644
>> --- a/drivers/media/i2c/tvp514x.c
>> +++ b/drivers/media/i2c/tvp514x.c
>> @@ -35,7 +35,9 @@
>>  #include <linux/videodev2.h>
>>  #include <linux/module.h>
>>  #include <linux/v4l2-mediabus.h>
>> +#include <linux/of_device.h>
>>
>> +#include <media/v4l2-of.h>
>>  #include <media/v4l2-async.h>
>>  #include <media/v4l2-device.h>
>>  #include <media/v4l2-common.h>
>> @@ -1056,6 +1058,58 @@ static struct tvp514x_decoder tvp514x_dev = {
>>
>>  };
>>
>> +#if defined(CONFIG_OF)
>> +static const struct of_device_id tvp514x_of_match[] = {
>> +     {.compatible = "ti,tvp5146-decoder", },
>> +     {.compatible = "ti,tvp5146m2-decoder", },
>> +     {.compatible = "ti,tvp5147-decoder", },
>> +     {.compatible = "ti,tvp5147m1-decoder", },
>> +     {},
>> +};
>> +MODULE_DEVICE_TABLE(of, tvp514x_of_match);
>> +
>> +static void tvp514x_get_pdata(struct i2c_client *client,
>> +                           struct tvp514x_decoder *decoder)
>> +{
>> +     if (!client->dev.platform_data && client->dev.of_node) {
>> +             struct device_node *endpoint;
>> +
>> +             endpoint = v4l2_of_get_next_endpoint(client->dev.of_node, NULL);
>> +             if (endpoint) {
>> +                     struct tvp514x_platform_data *pdata;
>> +                     struct v4l2_of_endpoint bus_cfg;
>> +                     unsigned int flags;
>> +
>> +                     pdata =
>> +                        devm_kzalloc(&client->dev,
>> +                                     sizeof(struct tvp514x_platform_data),
>
> sizeof(*pdata) ? That's the preferred style, as it makes sure that you will
> still allocate the right amount of memory if the type of the pdata variable
> changes (that's pretty unlikely here of course, but the general principle
> holds true).
>
OK will fix it.

>> +                                     GFP_KERNEL);
>> +                     if (!pdata)
>> +                             return;
>> +
>> +                     v4l2_of_parse_endpoint(endpoint, &bus_cfg);
>> +                     flags = bus_cfg.bus.parallel.flags;
>> +
>> +                     if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
>> +                             pdata->hs_polarity = 1;
>> +                     if (flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
>> +                             pdata->vs_polarity = 1;
>> +                     if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING)
>> +                             pdata->clk_polarity = 1;
>> +                     decoder->pdata = pdata;
>> +             }
>> +     }
>
> As pointed out by Sascha in his review of your mt9p031 patch, you need to use
> client->dev.platform_data if client->dev.of_node is NULL.
>
OK

>> +}
>> +#else
>> +#define tvp514x_of_match NULL
>> +
>> +static void tvp514x_get_pdata(struct i2c_client *client,
>> +                           struct tvp514x_decoder *decoder)
>> +{
>> +     decoder->pdata = client->dev.platform_data;
>> +}
>> +#endif
>> +
>>  /**
>>   * tvp514x_probe() - decoder driver i2c probe handler
>>   * @client: i2c driver client device structure
>> @@ -1075,11 +1129,6 @@ tvp514x_probe(struct i2c_client *client, const struct
>> i2c_device_id *id) if (!i2c_check_functionality(client->adapter,
>> I2C_FUNC_SMBUS_BYTE_DATA)) return -EIO;
>>
>> -     if (!client->dev.platform_data) {
>> -             v4l2_err(client, "No platform data!!\n");
>> -             return -ENODEV;
>> -     }
>> -
>>       decoder = devm_kzalloc(&client->dev, sizeof(*decoder), GFP_KERNEL);
>>       if (!decoder)
>>               return -ENOMEM;
>> @@ -1090,8 +1139,11 @@ tvp514x_probe(struct i2c_client *client, const struct
>> i2c_device_id *id) memcpy(decoder->tvp514x_regs, tvp514x_reg_list_default,
>>                       sizeof(tvp514x_reg_list_default));
>>
>> -     /* Copy board specific information here */
>> -     decoder->pdata = client->dev.platform_data;
>> +     tvp514x_get_pdata(client, decoder);
>
> Getter functions usually return a value. The code would (at least in my
> opinion) be clearer if you modifieid tvp514x_get_pdata() to return a pointer
> to the pdata instead of assigning it directly to decoder->pdata inside the
> function.
>
hmmm thats what my earlier RFC  version did, Sylwester suggested this way.
I'll make it as per your suggestion.

>> +     if (!decoder->pdata) {
>> +             v4l2_err(client, "No platform data!!\n");
>> +             return -EPROBE_DEFER;
>
> Why EPROBE_DEFER ? If there's no pdata now you won't magically get it later
> :-)
>
:-)

>> +     }
>>
>>       /**
>>        * Fetch platform specific data, and configure the
>> @@ -1242,6 +1294,7 @@ MODULE_DEVICE_TABLE(i2c, tvp514x_id);
>>
>>  static struct i2c_driver tvp514x_driver = {
>>       .driver = {
>> +             .of_match_table = tvp514x_of_match,
>
> Please use of_match_ptr() instead of defining tvp514x_of_match as NULL above.
>
OK.

Regards,
--Prabhakar Lad