Re: [PATCH] IIO AD7923 iio_consumer support

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

Le 05/10/2013 11:35, Lars-Peter Clausen a écrit :
> On 10/05/2013 11:18 AM, leroy christophe wrote:
>> 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.
>>
> If you are using device tree you can specify the mapping inside the
> devicetree. Have a look at
> Documentation/devicetree/bindings/iio/iio-bindings.txt
>
>
Yes, I saw that. Is there anything that shall be done in the driver to 
support it, or is it automatic ?

Christophe