[PATCH v3 0/7] ARM timer clock api support
Russell King - ARM Linux
linux at arm.linux.org.uk
Tue Mar 15 04:51:17 EDT 2011
On Fri, Mar 11, 2011 at 07:48:48AM -0600, Rob Herring wrote:
> Russell,
>
> On 03/11/2011 02:16 AM, Russell King - ARM Linux wrote:
>> On Tue, Mar 08, 2011 at 05:34:30PM -0600, Rob Herring wrote:
>>> From: Rob Herring<rob.herring at calxeda.com>
>>>
>>> This patch series converts ARM sp804 timer and smp_twd timer to use the clock
>>> api.
>>
>> This is what I came up with - I've still not sorted these patches out,
>> the second is a superset of the first.
>
> Any comments on the smp_twd patch? Colin plans to base his cpufreq
> patches on it.
>
>> + clk = clk_get_sys(name, NULL);
>> + if (IS_ERR(clk)) {
>> + pr_err("sp804: %s clock not found, defaulting to 1MHz: %d\n",
>> + name, ERR_PTR(clk));
>> + } else {
>> + int err = clk_enable(clk);
>> + if (err != 0) {
>> + pr_err("sp804: %s clock failed to enable: %d\n",
>> + name, err);
>> + clk_put(clk);
>> + } else {
>> + rate = clk_get_rate(clk);
>> + }
>
> You previously said this should fully move to using the clock api.
> Presumably, that meant no default freq of 1MHz.
>
> Also, my patch allows for clksrc and clkevent timers to have different
> clocks.
So will mine. Note that 'name' is passed in, which is the clocksource
name, and is also used for clk_sys_get(). The same thing will happen
with clockevents too.
> Currently, no h/w needs that, but it could happen. Even if they
> are the same clk, you are introducing a requirement on the calling order
> of sp804_clocksource_init and sp804_clockevents_init.
No I'm not, and I've no idea where you got that idea from. You'll notice
that nothing to do with the clk is stored in a global variable.
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