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

[<Eugen.Hristev@microchip.com>]

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
>