From mboxrd@z Thu Jan  1 00:00:00 1970
From: viresh.kumar@st.com (Viresh KUMAR)
Date: Tue, 22 Jun 2010 09:30:54 +0530
Subject: [PATCH V2] GPIO PL061: Adding Clk framework support
In-Reply-To: <AANLkTim0x5_4re3CWzWDRr1QMq46sQa1SCSyAiymmiUW@mail.gmail.com>
References: <1277103463-7311-1-git-send-email-viresh.kumar@st.com>	<20100621154121.GA4290@debian>
	<AANLkTim0x5_4re3CWzWDRr1QMq46sQa1SCSyAiymmiUW@mail.gmail.com>
Message-ID: <4C203576.2060200@st.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 6/21/2010 11:04 PM, Linus Walleij wrote:
> 2010/6/21 Rabin Vincent <rabin@rab.in>:
>> On Mon, Jun 21, 2010 at 12:27:43PM +0530, Viresh KUMAR wrote:
>>> +     chip->clk = clk_get(&dev->dev, NULL);
>>> +     if (IS_ERR(chip->clk)) {
>>> +             ret = PTR_ERR(chip->clk);
>>> +             goto iounmap;
>>> +     }
>>
>> Have you verified that all platforms using this driver already have
>> clocks with the appropriate names?   Otherwise this patch will break
>> those platforms.
> 
> The ARM Versatiles and RealViews are always clocked I think,
> so clock support should be optional.
> 
> When I added a clock lookup to the PL08x block recently I used
> a construct like this for an optional clock:
> 
> chip->clk = clk_get(&dev->dev, NULL);
> if (IS_ERR(chip->clk)) {
>        ret = PTR_ERR(chip->clk);
>        if (ret == -ENOENT)
>           /* No block clock in this platform */
>           chip->clk = NULL;
>        else
>           goto iounmap;
> }
> 
> This will work whenever clkdevice is used, since that
> returns -ENOENT for nonexisting entries.
> 
> Then:
> 
> if (chip->clk)
>   clk_enable(chip->clk);
> 

Will modify it, as suggested.

thanks
viresh.