[PATCHv3] watchdog: add support for the Synopsys DesignWare WDT

[Russell King - ARM Linux]

On Fri, Jan 07, 2011 at 10:13:50PM +0530, viresh kumar wrote:
> > +
> > +       dw_wdt.clk = clk_get(&pdev->dev, NULL);
> > +       if (IS_ERR_OR_NULL(dw_wdt.clk))
> > +               return -ENODEV;
> 
> should release mem_region and free ioremaped space.
> Also, may be we can continue here in case of error too.
> Some platforms might nor support clock framework. You can enable and
> disable clk's
> if dw_wdt.clk is !NULL

And some platforms have been known to return NULL for clk_get() as they
don't support more than one clock.

arch/arm/mach-aaec2000/core.c:struct clk *clk_get(struct device *dev, const char *id)
arch/arm/mach-aaec2000/core.c-{
arch/arm/mach-aaec2000/core.c-  return dev && strcmp(dev_name(dev), "mb:16") ==
0 ? NULL : ERR_PTR(-ENOENT);
--
arch/arm/mach-at91/at91x40.c:struct clk *clk_get(struct device *dev, const char
*id)
arch/arm/mach-at91/at91x40.c-{
arch/arm/mach-at91/at91x40.c-   return NULL;
--
arch/arm/mach-netx/fb.c:struct clk *clk_get(struct device *dev, const char *id)
arch/arm/mach-netx/fb.c-{
arch/arm/mach-netx/fb.c-        return dev && strcmp(dev_name(dev), "fb") == 0 ? NULL : ERR_PTR(-ENOENT);

Please stick to the conventions of the API in the driver.  IS_ERR() values
mean we failed.  Anything else must be considered success.  Don't assume
NULL means we failed.