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

On Fri, Jan 07, 2011 at 04:52:50PM +0000, Russell King - ARM Linux wrote:

On Fri, Jan 07, 2011 at 10:13:50PM +0530, viresh kumar wrote:

quoted

quoted

+
+ ? ? ? 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.

Ok, so I'll change the driver to get the clock rate of the watchdog 
through platform data for those that don't provide a struct clk and 
clk_get_rate() returns 0.

Looking at mach-aaec2000 and mach-netx they don't provide a 
clk_get_rate() which from linux/clk.h doesn't look like it's optional.  
Should these platforms have some kind of stub clk_get_rate()?

Jamie