[PATCH 1/4] PM/Domains: Add support for retrieving genpd performance states information

[Thara Gopinath <thara.gopinath@linaro.org>]

Add two new APIs in the genpd framework,
dev_pm_genpd_get_performance_state to return the current performance
state of a power domain and dev_pm_genpd_performance_state_count to
return the total number of performance states supported by a
power domain. Since the genpd framework does not maintain
a count of number of performance states supported by a power domain,
introduce a new callback(.get_performance_state_count) that can be used
to retrieve this information from power domain drivers.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
---
 drivers/base/power/domain.c | 38 ++++++++++++++++++++++++++++++++++++++
 include/linux/pm_domain.h   | 18 ++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index b063bc4..17e0375 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -413,6 +413,44 @@ int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state)
 }
 EXPORT_SYMBOL_GPL(dev_pm_genpd_set_performance_state);
 
+int dev_pm_genpd_get_performance_state(struct device *dev,
+				       unsigned int *state)
+{
+	struct generic_pm_domain *genpd;
+
+	genpd = dev_to_genpd(dev);
+	if (IS_ERR(genpd))
+		return -ENODEV;
+
+	genpd_lock(genpd);
+	*state = genpd->performance_state;
+	genpd_unlock(genpd);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(dev_pm_genpd_get_performance_state);
+
+int dev_pm_genpd_performance_state_count(struct device *dev,
+					 unsigned int *count)
+{
+	struct generic_pm_domain *genpd;
+	int ret;
+
+	genpd = dev_to_genpd(dev);
+	if (IS_ERR(genpd))
+		return -ENODEV;
+
+	if (unlikely(!genpd->get_performance_state_count))
+		return -EINVAL;
+
+	genpd_lock(genpd);
+	ret = genpd->get_performance_state_count(genpd, count);
+	genpd_unlock(genpd);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_genpd_performance_state_count);
+
 static int _genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 {
 	unsigned int state_idx = genpd->state_idx;
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 91d9bf4..0e5f502 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -117,6 +117,8 @@ struct generic_pm_domain {
 						 struct dev_pm_opp *opp);
 	int (*set_performance_state)(struct generic_pm_domain *genpd,
 				     unsigned int state);
+	int (*get_performance_state_count)(struct generic_pm_domain *genpd,
+					   unsigned int *count);
 	struct gpd_dev_ops dev_ops;
 	s64 max_off_time_ns;	/* Maximum allowed "suspended" time. */
 	bool max_off_time_changed;
@@ -204,6 +206,10 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 		  struct dev_power_governor *gov, bool is_off);
 int pm_genpd_remove(struct generic_pm_domain *genpd);
 int dev_pm_genpd_set_performance_state(struct device *dev, unsigned int state);
+int dev_pm_genpd_get_performance_state(struct device *dev,
+				       unsigned int *state);
+int dev_pm_genpd_performance_state_count(struct device *dev,
+					 unsigned int *count);
 
 extern struct dev_power_governor simple_qos_governor;
 extern struct dev_power_governor pm_domain_always_on_gov;
@@ -251,6 +257,18 @@ static inline int dev_pm_genpd_set_performance_state(struct device *dev,
 	return -ENOTSUPP;
 }
 
+static inline int dev_pm_genpd_get_performance_state(struct device *dev,
+						     unsigned int *state);
+{
+	return -ENOTSUPP;
+}
+
+static inline int dev_pm_genpd_performance_state_count(struct device *dev,
+						       unsigned int *count);
+{
+	return -ENOTSUPP;
+}
+
 #define simple_qos_governor		(*(struct dev_power_governor *)(NULL))
 #define pm_domain_always_on_gov		(*(struct dev_power_governor *)(NULL))
 #endif
-- 
2.1.4