[PATCH V2] GPIO PL061: Adding Clk framework support

On 6/21/2010 11:04 PM, Linus Walleij wrote:

2010/6/21 Rabin Vincent [off-list ref]:

quoted

On Mon, Jun 21, 2010 at 12:27:43PM +0530, Viresh KUMAR wrote:

quoted

+     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.