Re: [RFC,PATCH 1/3] Add a common struct clk

On Thu, Feb 10, 2011 at 09:21:14AM +1300, Ryan Mallon wrote:

On 02/09/2011 07:41 PM, Jeremy Kerr wrote:

Hi Jeremy,

Couple more comments below.

~Ryan

[...]

quoted

+int clk_enable(struct clk *clk)
+{
+     unsigned long flags;
+     int ret = 0;
+
+     spin_lock_irqsave(&clk->enable_lock, flags);

        WARN_ON(clk->prepare_count = 0); ?

quoted

+     if (clk->enable_count = 0 && clk->ops->enable)
+             ret = clk->ops->enable(clk);

Does it make sense to have a clock with no enable function which still
returns success from clk_enable? Do we have any platforms which have
NULL clk_enable functions?

I think that for enable/disable at least we should require platforms to
provide functions and oops if they have failed to do so. In the rare
case that a platform doesn't need to do anything for enable/disable they
can just supply empty functions.

It's possible to be NULL. So are set_rate/get_rate.
Ideally, if it's NULL: 
prepare/unprepare: only call parent's prepare/unprepare
enable/disable: only call parent's enable/disable
set_rate: fail
get_rate: reture parent's get_rate
set_parent: fail
get_parent: fail

Thanks
Richard

quoted

+
+     if (!ret)
+             clk->enable_count++;
+     spin_unlock_irqrestore(&clk->enable_lock, flags);
+
+     return ret;
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+