Re: [PATCH v2] iio: accel: add Freescale MMA7455L/MMA7456L 3-axis accelerometer driver

[Lars-Peter Clausen <lars@metafoo.de>]

On 10/20/2015 01:00 PM, Joachim Eastwood wrote:
> On 20 October 2015 at 10:05, Lars-Peter Clausen <lars@metafoo.de> wrote:
>> On 10/19/2015 09:00 PM, Joachim Eastwood wrote:
>> [...]
>>> +config MMA7455
>>> +     tristate "Freescale MMA7455L/MMA7456L Accelerometer Driver"
>>> +     depends on I2C || SPI_MASTER
>>> +     select IIO_BUFFER
>>> +     select IIO_TRIGGERED_BUFFER
>>> +     select MMA7455_I2C if I2C
>>> +     select MMA7455_SPI if SPI
>>
>> Ah, damm, I shouldn't have said bmg160 is a good example without actually
>> looking at its Kconfig entry. Only saw the C files and those looked good.
>>
>> This is still problematic. The depends on clause allows this driver to be
>> built-in if either I2C is built-in or SPI_MASTER is built-in. And then the
>> respective I2C and SPI modules will also be selected as built-in even though
>> the I2C symbol is only selected as a module. So you now have built-in code
>> that tries to reference code that is only available as a module.
>>
>> A better solution is to make the Kconfig entries for the I2C and SPI modules
>> user selectable and then let them select the main module.
> 
> Something like this:
> 
> config MMA7455
>         tristate
> 
> config MMA7455_I2C
>         tristate "Freescale MMA7455L/MMA7456L Accelerometer I2C Driver"
>         depends on I2C
>         select IIO_BUFFER
>         select IIO_TRIGGERED_BUFFER
>         select MMA7455
>         select REGMAP_I2C
>         help
>             ...
> 
> config MMA7455_SPI
>         tristate "Freescale MMA7455L/MMA7456L Accelerometer SPI Driver"
>         depends on SPI_MASTER
>         select IIO_BUFFER
>         select IIO_TRIGGERED_BUFFER
>         select MMA7455
>         select REGMAP_SPI
>         help
>             ...

Yes, but move the select IIO_BUFFER and IIO_TRIGGERED_BUFFER to the shared
symbol.