Re: [PATCH RFC v2 07/12] PM / Domains: export pm_genpd_lookup_name

From: amit daniel kachhap
Date: Tue Nov 25 2014 - 03:48:41 EST


On Tue, Nov 25, 2014 at 1:05 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 24 November 2014 at 14:04, Amit Daniel Kachhap
> <amit.daniel@xxxxxxxxxxx> wrote:
>> This API may be needed to set the power domain parent/child relationship
>> in the power domain platform driver. The parent relationship is
>> generally set after the child power domain is registered with the power
>> domain subsystem. In this case, pm_genpd_lookup_name API might be
>> useful.
>
> I think this is a step in the wrong direction. Instead we should be
> working on removing the "name" based APIs from genpd.
>
> The proper way should be to pass the PM domain as a parameter to the
> APIs instead.
Yes i understand but i had a special requirement for using this API
during pd probe.
I cannot use hierarchy to represent parent/child pd nodes as it will
break the existing SoC's. In my case all the PD nodes are linear. The
parent/child relationship are established in the second pass after all
the PD entries are registered with the help of this API.
Although there a way that i can always keep parent PD's before the
child PD's in DT in linear order. Will check this approach.

Regards,
Amit
>
> Kind regards
> Uffe
>
>>
>> Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
>> ---
>> drivers/base/power/domain.c | 3 ++-
>> include/linux/pm_domain.h | 7 +++++++
>> 2 files changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
>> index fb83d4a..b0e1c2f 100644
>> --- a/drivers/base/power/domain.c
>> +++ b/drivers/base/power/domain.c
>> @@ -49,7 +49,7 @@
>> static LIST_HEAD(gpd_list);
>> static DEFINE_MUTEX(gpd_list_lock);
>>
>> -static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
>> +struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
>> {
>> struct generic_pm_domain *genpd = NULL, *gpd;
>>
>> @@ -66,6 +66,7 @@ static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
>> mutex_unlock(&gpd_list_lock);
>> return genpd;
>> }
>> +EXPORT_SYMBOL_GPL(pm_genpd_lookup_name);
>>
>> struct generic_pm_domain *dev_to_genpd(struct device *dev)
>> {
>> diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
>> index 2e0e06d..aedcec3 100644
>> --- a/include/linux/pm_domain.h
>> +++ b/include/linux/pm_domain.h
>> @@ -150,6 +150,8 @@ extern int pm_genpd_name_poweron(const char *domain_name);
>>
>> extern struct dev_power_governor simple_qos_governor;
>> extern struct dev_power_governor pm_domain_always_on_gov;
>> +
>> +extern struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name);
>> #else
>>
>> static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
>> @@ -221,6 +223,11 @@ static inline int pm_genpd_name_poweron(const char *domain_name)
>> {
>> return -ENOSYS;
>> }
>> +static inline
>> +struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
>> +{
>> + return NULL;
>> +}
>> #define simple_qos_governor NULL
>> #define pm_domain_always_on_gov NULL
>> #endif
>> --
>> 1.7.9.5
>>
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