Re: [PATCH] MFD: ab8500: New ab8500_gpadc APIs and reentrance

From: Linus Walleij
Date: Wed Mar 02 2011 - 09:12:46 EST


2011/3/2 Samuel Ortiz <sameo@xxxxxxxxxxxxxxx>:

>> +/**
>> + * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
>> + * (i.e. the first GPADC in the instance list)
>> + */
>> +struct ab8500_gpadc *ab8500_gpadc_get(void)
>> +{
>> +     struct ab8500_gpadc *gpadc;
>> +     gpadc = list_first_entry(&ab8500_gpadc_list, struct ab8500_gpadc, node);
>> +
>> +     return gpadc;
>> +}

> This seems really arbitrary. We argued with Mattias about it, and giving
> drivers access to your ADCs means they should somehow have a pointer back to
> the right ADC. That's not the case here, and while it will just work fine
> whenever you have one ADC on your board, you'll probably be relying on some
> sort of device probe order otherwise.

I guess the solution is to rewrite that function to take a parameter
then, such as:

struct ab8500_gpadc *ab8500_gpadc_get(char *name)

If name is then just a strcmpm(dev_name(gpadc->dev), name)
the client use will be something like:

struct ab8500_gpadc *gpadc = ab8500_gpadc_get("ab8500-gpadc.0");

For the first GPDC in the system (unless .init_name is specified
by the ab8500-core when creating the device).

Fair enough?

Yours,
Linus Walleij
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/