Subject: [PATCH 1/2] ARM: OMAP3+: TWL: add support for mapping platform data via pdata-quirks

From: [email-masked] (Tero Kristo)
Date: Fri, 10 Oct 2014 20:54:29 +0300

On 10/10/2014 08:00 PM, Tony Lindgren wrote:
> * Tero Kristo <[email-masked]> [141010 06:41]:
>> Device tree based boot does not currently support DVFS voltage scaling,
>> as the VC/VP mapping is broken. This patch adds support to provide
>> platform data in the device tree boot case also, basically to pass the
>> function pointers to the vc/vp core for voltage changes.
>>
>> Signed-off-by: Tero Kristo <[email-masked]>
>> ---
>>   arch/arm/mach-omap2/pdata-quirks.c |    8 ++--
>>   arch/arm/mach-omap2/twl-common.c   |   88 ++++++++++++++++++++++++++++++++----
>>   arch/arm/mach-omap2/twl-common.h   |    2 +
>>   3 files changed, 84 insertions(+), 14 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/pdata-quirks.c b/arch/arm/mach-omap2/pdata-quirks.c
>> index 90c88d4..03e4a86 100644
>> --- a/arch/arm/mach-omap2/pdata-quirks.c
>> +++ b/arch/arm/mach-omap2/pdata-quirks.c
>> @@ -311,10 +311,10 @@ void omap_auxdata_legacy_init(struct device *dev)
>>   	if (dev->platform_data)
>>   		return;
>>
>> -	if (strcmp("twl4030-gpio", dev_name(dev)))
>> -		return;
>> -
>> -	dev->platform_data = &twl_gpio_auxdata;
>> +	if (!strcmp("twl4030-gpio", dev_name(dev)))
>> +		dev->platform_data = &twl_gpio_auxdata;
>> +	else
>> +		dev->platform_data = omap_twl_match_regulator(dev);
>>   }
>
> I think now you're passing also dev->platform_data for all the
> other devices as this gets called for any devices added.

This is true, however omap_twl_match_regulator will return NULL if no 
match against a DT compatible string is found.

>
> So you probale should use something like this instead:
>
> 	if (!strcmp("twl4030-gpio", dev_name(dev)))
> 		dev->platform_data = &twl_gpio_auxdata;
>
> 	if (!strcmp("twl4030-whatever-you-need", dev_name(dev)))
> 		dev->platform_data = &twl_gpio_auxdata;

This is what I did first, however the dev_name strings for the 
regulators are pretty complex: i2c at xyz:twl at 48:twl4030-vdd1-regulator or 
something like that, and I need to do string comparisons against 5 
different devices. The current approach does a DT compatible match, 
which at least looks neater if it isn't more efficient also.

-Tero