[PATCH v4 3/5] media: mali-c55: Add Mali-C55 ISP driver

[Dan Scally]

Hi Sakari - sorry, one part I missed...

On 23/05/2024 09:03, Sakari Ailus wrote:
>> +
>> +int mali_c55_isp_s_stream(struct mali_c55_isp *isp, int enable)
> Have you considered {enable,disable}_streams? All new drivers should use
> these instead of s_stream() now.


Although named s_stream this is actually a purely internal function - it's not exposed as part of 
the subdev video ops. The resizer subdevices similarly don't expose an .s_stream() operation, 
they're simply started in the callpath of mali_c55_vb2_start_streaming(). I'll split the stop 
functionality into mali_c55_isp_stop_stream() and rename this mali_c55_isp_start_stream() to make 
that less confusing.


The TPG subdevice on the other hand does expose an .s_stream() operation, since the intention was to 
model it exactly like a connected external subdevice. I can switch to the .enable_streams() 
operation there.

>
>> +{
>> +	struct mali_c55 *mali_c55 = isp->mali_c55;
>> +	struct media_pad *source_pad;
>> +	struct media_pad *sink_pad;
>> +	int ret;
>> +
>> +	if (!enable) {
>> +		if (isp->source)
>> +			v4l2_subdev_call(isp->source, video, s_stream, false);
>> +		isp->source = NULL;
>> +
>> +		mali_c55_isp_stop(mali_c55);
>> +
>> +		return 0;
>> +	}
>> +
>> +	sink_pad = &isp->pads[MALI_C55_ISP_PAD_SINK_VIDEO];
>> +	source_pad = media_pad_remote_pad_unique(sink_pad);
>> +	if (IS_ERR(source_pad)) {
>> +		dev_err(mali_c55->dev, "Failed to get source for ISP\n");
>> +		return PTR_ERR(source_pad);
>> +	}
>> +
>> +	isp->source = media_entity_to_v4l2_subdev(source_pad->entity);
>> +
>> +	isp->frame_sequence = 0;
>> +	ret = mali_c55_isp_start(mali_c55);
>> +	if (ret) {
>> +		dev_err(mali_c55->dev, "Failed to start ISP\n");
>> +		isp->source = NULL;
>> +		return ret;
>> +	}
>> +
>> +	ret = v4l2_subdev_call(isp->source, video, s_stream, true);
>> +	if (ret) {
>> +		dev_err(mali_c55->dev, "Failed to start ISP source\n");
>> +		mali_c55_isp_stop(mali_c55);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +