[PATCH V2] GPIO PL061: Adding Clk framework support
Linus Walleij
linus.ml.walleij at gmail.com
Mon Jun 21 13:34:59 EDT 2010
2010/6/21 Rabin Vincent <rabin at rab.in>:
> On Mon, Jun 21, 2010 at 12:27:43PM +0530, Viresh KUMAR wrote:
>> GPIO Clk is never enabled on Platforms, like: SPEAr, which are based upon clock
>> framework and use PL061 driver. This patch adds support for Clk enabling and
>> disabling as and when gpios are requested and freed.
> [...]
>> + 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);
etc
Yours,
Linus Walleij
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