Subject: [PATCH 2/6] ARM: s3c24xx: rx1950: Use PWM lookup table

From: [email-masked] (Krzysztof Kozlowski)
Date: Thu, 08 Oct 2015 10:00:23 +0900

On 08.10.2015 00:31, Thierry Reding wrote:
> On Wed, Oct 07, 2015 at 10:35:54AM +0900, Krzysztof Kozlowski wrote:
>> On 05.10.2015 21:47, Thierry Reding wrote:
>>> Use a PWM lookup table to provide the PWM to the pwm-backlight device.
>>> The driver has a legacy code path that is required only because boards
>>> still use the legacy method of requesting PWMs by global ID. Replacing
>>> these usages allows that legacy fallback to be removed.
>>>
>>> Cc: Kukjin Kim <[email-masked]>
>>> Cc: Krzysztof Kozlowski <[email-masked]>
>>> Signed-off-by: Thierry Reding <[email-masked]>
>>> ---
>>>  arch/arm/mach-s3c24xx/mach-rx1950.c | 8 ++++++--
>>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-s3c24xx/mach-rx1950.c b/arch/arm/mach-s3c24xx/mach-rx1950.c
>>> index 1d35ff375a01..774c982a7b7e 100644
>>> --- a/arch/arm/mach-s3c24xx/mach-rx1950.c
>>> +++ b/arch/arm/mach-s3c24xx/mach-rx1950.c
>>> @@ -375,6 +375,11 @@ static struct s3c2410fb_mach_info rx1950_lcd_cfg = {
>>>  
>>>  };
>>>  
>>> +static struct pwm_lookup rx1950_pwm_lookup[] = {
>>> +	PWM_LOOKUP("samsung-pwm", 0, "pwm-backlight.0", NULL, 48000,
>>
>> Why the dev_id is "pwm-backlight.0"? Created platform device name is
>> "pwm-backlight".
> 
> "pwm-backlight" is only the base name. The platform bus code will use
> the platform_device.id field and append it to the name as .<id> unless
> it is -1 in which case it will be skipped. So in the rx1950_backlight
> device the .id field isn't initialized at all, so it will be zeroed
> out and hence the device name will become "pwm-backlight.0".

Right, I missed the difference in device id.

The patch is fine:

Reviewed-by: Krzysztof Kozlowski <[email-masked]>

Best regards,
Krzysztof