[PATCH 1/3] PM / Domains: Initial PM clock support for genpd

[Ulf Hansson]

On 19 November 2014 18:25, Dmitry Torokhov <dmitry.torokhov at gmail.com> wrote:
> On Wed, Nov 19, 2014 at 03:00:36PM +0100, Ulf Hansson wrote:
>> It's quite common for PM domains to use PM clocks. Typically from SOC
>> specific code, the per device PM clock list is created and
>> pm_clk_suspend|resume() are invoked to handle clock gating/ungating.
>>
>> A step towards consolidation is to integrate PM clock support into
>> genpd, which is what this patch does.
>>
>> In this initial step, the calls to the pm_clk_suspend|resume() are
>> handled within genpd, but the per device PM clock list still needs to
>> be created from SOC specific code. It seems reasonable to have gendp to
>> handle that as well, but that left to future patches to address.
>>
>> It's not every users of genpd that are keen on using PM clocks thus we
>> need to provide this a configuration option for genpd. Therefore let's
>> add flag field in the genpd struct to keep this information and define
>> a new PM_DOMAIN_PM_CLK bit can then be set at initialization.
>>
>> Signed-off-by: Ulf Hansson <ulf.hansson at linaro.org>
>> ---
>>  drivers/base/power/domain.c | 7 +++++++
>>  include/linux/pm_domain.h   | 3 +++
>>  2 files changed, 10 insertions(+)
>>
>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>> index 3989eb6..42e328c 100644
>> --- a/drivers/base/power/domain.c
>> +++ b/drivers/base/power/domain.c
>> @@ -12,6 +12,7 @@
>>  #include <linux/pm_runtime.h>
>>  #include <linux/pm_domain.h>
>>  #include <linux/pm_qos.h>
>> +#include <linux/pm_clock.h>
>>  #include <linux/slab.h>
>>  #include <linux/err.h>
>>  #include <linux/sched.h>
>> @@ -1948,6 +1949,12 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
>>       genpd->domain.ops.complete = pm_genpd_complete;
>>       genpd->dev_ops.save_state = pm_genpd_default_save_state;
>>       genpd->dev_ops.restore_state = pm_genpd_default_restore_state;
>> +
>> +     if (genpd->flags & PM_DOMAIN_PM_CLK) {
>> +             genpd->dev_ops.stop = pm_clk_suspend;
>> +             genpd->dev_ops.start = pm_clk_suspend;
>
> The 2nd one is wrong.

Huh, thanks for spotting this.

>
>> +     }
>> +
>>       mutex_lock(&gpd_list_lock);
>>       list_add(&genpd->gpd_list_node, &gpd_list);
>>       mutex_unlock(&gpd_list_lock);
>> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
>> index 9d254e2..44c6931 100644
>> --- a/include/linux/pm_domain.h
>> +++ b/include/linux/pm_domain.h
>> @@ -14,6 +14,7 @@
>>  #include <linux/pm.h>
>>  #include <linux/err.h>
>>  #include <linux/of.h>
>> +#include <linux/bitops.h>
>>  #include <linux/notifier.h>
>>  #include <linux/cpuidle.h>
>>
>> @@ -76,6 +77,8 @@ struct generic_pm_domain {
>>                         struct device *dev);
>>       void (*detach_dev)(struct generic_pm_domain *domain,
>>                          struct device *dev);
>> +     unsigned int flags;             /* Bit field of configs for genpd */
>> +#define PM_DOMAIN_PM_CLK     BIT(0)  /* PM domain use PM clk */
>
> s/use/uses ?
>
> Are you planning on adding a separate flag for collecting clocks from OF
> on attach/detach?

Yes, I am thinking on that approach. Do you have any suggestions around this?

Kind regards
Uffe