Re: [PATCH] IIO AD7923 iio_consumer support

[leroy christophe <christophe.leroy@c-s.fr>]

Le 05/10/2013 10:41, Lars-Peter Clausen a écrit :
> On 10/05/2013 10:21 AM, Christophe Leroy wrote:
>> +		.consumer_channel = "channel_0",
>> +		.adc_channel_label = "0",
>> +	},
>> +	{
>> +		.consumer_dev_name = AD7923_NAME,
>> +		.consumer_channel = "channel_1",
>> +		.adc_channel_label = "1",
>> +	},
>> +	{
>> +		.consumer_dev_name = AD7923_NAME,
>> +		.consumer_channel = "channel_2",
>> +		.adc_channel_label = "2",
>> +	},
>> +	{
>> +		.consumer_dev_name = AD7923_NAME,
>> +		.consumer_channel = "channel_3",
>> +		.adc_channel_label = "3",
>> +	},
>> +	{ }
>> +};
> This is a mapping between channel names of the provider between the channel
> names of the consumer. So it is specific to a certain combination of
> consumer and provider and usually depend on how things are physically wired
> on your board. As such there can be no generic mapping and this needs to go
> into your machine/board driver. The mapping is usually passed to the IIO
> driver via its platform data.
>
> So e.g. imagine you have a provider like this driver and you have a consumer
> that has a "voltage" channel. And on your board channel 3 of the ADC is what
> you want to route to that consumer. Then your mapping would look like this:
>
> {
> 	.consumer_dev_name = "your_consumer_device.1",
> 	.consumer_channel = "voltage",
> 	.adc_channel_label = "AIN3",
> }
>
> And in your consumer driver you'd do:
>
> channel = iio_channel_get(dev, "voltage");
>
>
Thanks for the explanation.

Can the mapping be retrieved via of_platform ?

Indeed, the only exemple I found was in the lp8788_adc driver, which 
includes iio/machine.h and declares a default mapping, but it is based 
on platform_data, not of_platform.

Christophe