[PATCH v9 4/8] PM: domains: Add get_performance_state() callback

[Dmitry Osipenko <digetx@gmail.com>]

Add get_performance_state() callback that retrieves and initializes
performance state of a device attached to a power domain. This removes
inconsistency of the performance state with hardware state.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/base/power/domain.c | 32 +++++++++++++++++++++++++++++---
 include/linux/pm_domain.h   |  2 ++
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 3a13a942d012..8b828dcdf7f8 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2700,15 +2700,41 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
 		goto err;
 	} else if (pstate > 0) {
 		ret = dev_pm_genpd_set_performance_state(dev, pstate);
-		if (ret)
+		if (ret) {
+			dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
+				pd->name, ret);
 			goto err;
+		}
 		dev_gpd_data(dev)->default_pstate = pstate;
 	}
+
+	if (pd->get_performance_state && !dev_gpd_data(dev)->default_pstate) {
+		bool dev_suspended = false;
+
+		ret = pd->get_performance_state(pd, base_dev, &dev_suspended);
+		if (ret < 0) {
+			dev_err(dev, "failed to get performance state for power-domain %s: %d\n",
+				pd->name, ret);
+			goto err;
+		}
+
+		pstate = ret;
+
+		if (dev_suspended) {
+			dev_gpd_data(dev)->rpm_pstate = pstate;
+		} else if (pstate > 0) {
+			ret = dev_pm_genpd_set_performance_state(dev, pstate);
+			if (ret) {
+				dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
+					pd->name, ret);
+				goto err;
+			}
+		}
+	}
+
 	return 1;
 
 err:
-	dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
-		pd->name, ret);
 	genpd_remove_device(pd, dev);
 	return ret;
 }
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 67017c9390c8..4f78b31791ae 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -133,6 +133,8 @@ 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)(struct generic_pm_domain *genpd,
+				     struct device *dev, bool *dev_suspended);
 	struct gpd_dev_ops dev_ops;
 	s64 max_off_time_ns;	/* Maximum allowed "suspended" time. */
 	ktime_t next_wakeup;	/* Maintained by the domain governor */
-- 
2.32.0