From mboxrd@z Thu Jan  1 00:00:00 1970
From: sylvester.nawrocki@gmail.com (Sylwester Nawrocki)
Date: Fri, 31 Aug 2012 22:47:15 +0200
Subject: [PATCH 3/8] i2c: at91: use an id table for SoC dependent
 parameters
In-Reply-To: <5040CF80.8060201@atmel.com>
References: <1346404884-18451-1-git-send-email-ludovic.desroches@atmel.com>
 <1346404884-18451-4-git-send-email-ludovic.desroches@atmel.com>
 <20120831142944.GA23867@game.jcrosoft.org> <5040CF80.8060201@atmel.com>
Message-ID: <504122D3.70507@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 08/31/2012 04:51 PM, Nicolas Ferre wrote:
>>> diff --git a/arch/arm/mach-at91/at91rm9200.c b/arch/arm/mach-at91/at91rm9200.c
>>> index f2112f9..0bc91e5 100644
>>> --- a/arch/arm/mach-at91/at91rm9200.c
>>> +++ b/arch/arm/mach-at91/at91rm9200.c
>>> @@ -187,7 +187,7 @@ static struct clk_lookup periph_clocks_lookups[] = {
>>>   	CLKDEV_CON_DEV_ID("pclk", "ssc.0",&ssc0_clk),
>>>   	CLKDEV_CON_DEV_ID("pclk", "ssc.1",&ssc1_clk),
>>>   	CLKDEV_CON_DEV_ID("pclk", "ssc.2",&ssc2_clk),
>>> -	CLKDEV_CON_DEV_ID(NULL, "at91_i2c",&twi_clk),
>>> +	CLKDEV_CON_DEV_ID(NULL, "at91rm9200_i2c",&twi_clk),
>> use i2c-xxx as on other drivers
>>
>> and I do not like to have platform_device_id
> 
> Me, I like it and find this implementation very elegant.
> 
>> as we need to touch the driver to add a new soc
> 
> So what? We still keep the compatibility if the new SoC has it
> compatibility assured with previous revision: there is nothing to modify.

I agree. The driver would need to be touched to support new SoC only if
the IP there have had some differences, which would have needed to be 
resolved anyway.

>> please use platform data

Using platform data for the dt platforms would have been more troublesome,
wouldn't it ? I like Ludovic's approach which handles both: dt and non-dt 
cases in uniform way from the driver's POV.

> No, it does not have to be exposed to the user: these data are highly
> dependent on the actual hardware (IP revision in fact). So, no need to
> mess with platform data.

Agreed.
 
> So I will acknowledge Ludo's patches.
> 
> Bye,

--

Regards,
Sylwester