Re: [libcamera-devel] [PATCH 19/25] media: ov5647: Implement set_fmt pad operation

[Dafna Hirschfeld <dafna.hirschfeld@collabora.com>]

On 30.06.20 12:13, Jacopo Mondi wrote:
> Hi Dafna,
> 
> On Mon, Jun 29, 2020 at 06:54:43PM +0200, Dafna Hirschfeld wrote:
>>
>>
>> On 23.06.20 18:49, Jacopo Mondi wrote:
>>> Now that the driver supports more than a single mode, implement the
>>> .set_fmt pad operation and adjust the existing .get_fmt one to report
>>> the currently applied format.
>>>
>>> Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
>>> ---
>>>    drivers/media/i2c/ov5647.c | 67 +++++++++++++++++++++++++++++++++++---
>>>    1 file changed, 62 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
>>> index af9e6d43967d8..39e320f321bd8 100644
>>> --- a/drivers/media/i2c/ov5647.c
>>> +++ b/drivers/media/i2c/ov5647.c
>>> @@ -1016,15 +1016,72 @@ static int ov5647_enum_frame_size(struct v4l2_subdev *sd,
>>>    	return 0;
>>>    }
>>> -static int ov5647_set_get_fmt(struct v4l2_subdev *sd,
>>> +static int ov5647_get_pad_fmt(struct v4l2_subdev *sd,
>>>    			      struct v4l2_subdev_pad_config *cfg,
>>>    			      struct v4l2_subdev_format *format)
>>>    {
>>>    	struct v4l2_mbus_framefmt *fmt = &format->format;
>>> +	struct v4l2_mbus_framefmt *sensor_format;
>>> +	struct ov5647 *sensor = to_sensor(sd);
>>> -	/* Only one format is supported, so return that. */
>>> +	mutex_lock(&sensor->lock);
>>>    	memset(fmt, 0, sizeof(*fmt));
>>> -	*fmt = OV5647_DEFAULT_FORMAT;
>>> +
>>> +	switch (format->which) {
>>> +	case V4L2_SUBDEV_FORMAT_TRY:
>>> +		sensor_format = v4l2_subdev_get_try_format(sd, cfg, format->pad);
>>> +		break;
>>> +	default:
>>> +		sensor_format = &sensor->mode->format;
>>> +		break;
>>> +	}
>>> +
>>> +	*fmt = *sensor_format;
>>> +	mutex_unlock(&sensor->lock);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int ov5647_set_pad_fmt(struct v4l2_subdev *sd,
>>> +			      struct v4l2_subdev_pad_config *cfg,
>>> +			      struct v4l2_subdev_format *format)
>>> +{
>>> +	struct v4l2_mbus_framefmt *fmt = &format->format;
>>> +	struct ov5647 *sensor = to_sensor(sd);
>>> +	struct ov5647_mode *ov5647_mode_list;
>>> +	struct ov5647_mode *mode;
>>> +	unsigned int num_modes;
>>> +
>>> +	/*
>>> +	 * Default mbus code MEDIA_BUS_FMT_SBGGR10_1X10 if the requested one
>>> +	 * is not supported.
>>
>> In previous patch you added macros OV5647_DEFAULT_MODE, OV5647_DEFAULT_FORMAT
>> which comes from first format in the array 'ov5647_formats' which is MEDIA_BUS_FMT_SBGGR8_1X8.
> 
> Oh well, that's just an arbitrary selection of the format the sensor
> is initialized with.
> 
>> But here you set the default format to MEDIA_BUS_FMT_SBGGR10_1X10
>>
> 
> I chose the _1x10 version as it supports more resolution than the _1X8
> one. The v4l2-spec says if the requested format is not supported the
> closed possible match should be reported. It is easy to identify what
> a closes possible match is when considering the image size, but for image
> formats the "closes possible match" might be tricky to define.
> 
> I can change the sensor initial default state if you think that's the
> case, but I don't think the initial configuration and the adjusted format
> returned from s_stream() should be considered related. Do you agree or
> is there any part of the specs I'm overlooking ?

I also don't see it in the spec, but I think it is nicer that
s_fmt default to the initial value. This is also the first value
returned in the enumeration.

Thanks,
    d

> 
> Thanks
>    j
> 
> 
>>> +	 */
>>> +	if (fmt->code == MEDIA_BUS_FMT_SBGGR8_1X8) {
>>> +		ov5647_mode_list = ov5647_sbggr8_modes;
>>> +		num_modes = ARRAY_SIZE(ov5647_sbggr8_modes);
>>> +	} else {
>>> +		ov5647_mode_list = ov5647_sbggr10_modes;
>>> +		num_modes = ARRAY_SIZE(ov5647_sbggr10_modes);
>>> +	}
>>> +
>>> +	mode = v4l2_find_nearest_size(ov5647_mode_list, num_modes,
>>> +				      format.width, format.height,
>>> +				      fmt->width, fmt->height);
>>> +
>>> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
>>> +		mutex_lock(&sensor->lock);
>>> +		*v4l2_subdev_get_try_format(sd, cfg, format->pad) = mode->format;
>>> +		*fmt = mode->format;
>>> +		mutex_unlock(&sensor->lock);
>>> +
>>> +		return 0;
>>> +	}
>>> +
>>> +	/* Update the sensor mode and apply at it at streamon time. */
>>> +	mutex_lock(&sensor->lock);
>>> +	sensor->mode = mode;
>>> +	*fmt = mode->format;
>>> +	mutex_unlock(&sensor->lock);
>>>    	return 0;
>>>    }
>>> @@ -1068,8 +1125,8 @@ static int ov5647_get_selection(struct v4l2_subdev *sd,
>>>    static const struct v4l2_subdev_pad_ops ov5647_subdev_pad_ops = {
>>>    	.enum_mbus_code		= ov5647_enum_mbus_code,
>>>    	.enum_frame_size	= ov5647_enum_frame_size,
>>> -	.set_fmt		= ov5647_set_get_fmt,
>>> -	.get_fmt		= ov5647_set_get_fmt,
>>> +	.set_fmt		= ov5647_set_pad_fmt,
>>> +	.get_fmt		= ov5647_get_pad_fmt,
>>>    	.get_selection		= ov5647_get_selection,
>>>    };
>>>