Subject: [PATCH 05/17] pwm: samsung: remove s5p64x0 related pwm codes

From: [email-masked] (Tomasz Figa)
Date: Tue, 08 Jul 2014 17:43:37 +0200

Kukjin,

On 08.07.2014 00:23, Kukjin Kim wrote:
> On 07/04/14 17:10, Tomasz Figa wrote:
>> Hi Kukjin,
>>
> Tomasz,
> 
>> On 30.06.2014 23:32, Kukjin Kim wrote:
>>> This patch removes supporting s5p64x0 related pwm codes because of
>>> no more support for S5P6440 and S5P6450 SoCs. And this patch changes
>>> the name of s5p6440-pwm to exynos-pwm instead.
>>>
>>> Signed-off-by: Kukjin Kim<[email-masked]>
>>> Cc: Thierry Reding<[email-masked]>
>>> ---
>>>   Documentation/devicetree/bindings/pwm/pwm-samsung.txt |    1 -
>>>   arch/arm/boot/dts/exynos4210-universal_c210.dts       |    2 +-
>>>   drivers/clocksource/samsung_pwm_timer.c               |   13 -------------
>>>   drivers/pwm/pwm-samsung.c                             |    5 ++---
>>>   4 files changed, 3 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
>>> index 5538de9..43925d3 100644
>>> --- a/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
>>> +++ b/Documentation/devicetree/bindings/pwm/pwm-samsung.txt
>>> @@ -11,7 +11,6 @@ Required properties:
>>>   - compatible : should be one of following:
>>>       samsung,s3c2410-pwm - for 16-bit timers present on S3C24xx SoCs
>>>       samsung,s3c6400-pwm - for 32-bit timers present on S3C64xx SoCs
>>> -    samsung,s5p6440-pwm - for 32-bit timers present on S5P64x0 SoCs
>>>       samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
>>>   			  Exynos4210 rev0 SoCs
>>>       samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
>>> diff --git a/arch/arm/boot/dts/exynos4210-universal_c210.dts b/arch/arm/boot/dts/exynos4210-universal_c210.dts
>>> index d50eb3a..0ca26e0 100644
>>> --- a/arch/arm/boot/dts/exynos4210-universal_c210.dts
>>> +++ b/arch/arm/boot/dts/exynos4210-universal_c210.dts
>>> @@ -461,7 +461,7 @@
>>>   	};
>>>
>>>   	pwm at 139D0000 {
>>> -		compatible = "samsung,s5p6440-pwm";
>>> +		compatible = "samsung,exynos4210-pwm";
>>
>> There is a reason to use a different compatible string for Exynos4210
>> rev0. The PWM block is used as a timer there, while on newer revs MCT is
>> used. Sorry, but I have to NAK this patch.
>>
> I remember why exynos4210-universal_c210 uses PWM...OK.
> 
>> As I explained in my reply to patch 11/17, I'd suggest keeping the PWM
>> drivers as is, because there is no need to remove support for DT
>> compatible strings.
>>
> OK, let me remove pwm related patches in this series but I think need to 
> update the compatible strings, at least remove non-support SoC in doc?...

Device tree bindings are defined according to the first SoC in which
given hardware variant appeared and since they are stable, they should
stay as is. I don't think it will have any negative effects on
maintenance costs and it doesn't imply that the SoC is still supported.

(Anyway, with DT you can boot virtually any SoC, without the kernel
being aware of it, as long as it supports all the necessary IP blocks.)

Best regards,
Tomasz