[4.4.y-cip,04/23] PM / OPP: Introduce dev_pm_opp_get_max_transition_latency()
diff mbox series

Message ID 20200708154554.26450-5-wens@csie.org
State Changes Requested
Headers show
Series
  • PM / OPP v2 & cpufreq backports part 2
Related show

Commit Message

Chen-Yu Tsai (Moxa) July 8, 2020, 3:45 p.m. UTC
From: Viresh Kumar <viresh.kumar@linaro.org>

commit 2174344765f472895c076d703c9cdc58215e1393 upstream.

In few use cases (like: cpufreq), it is desired to get the maximum
latency for changing OPPs. Add support for that.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chen-Yu Tsai (Moxa) <wens@csie.org>
---
 drivers/base/power/opp/core.c | 17 +++++++++++++++++
 include/linux/pm_opp.h        |  6 ++++++
 2 files changed, 23 insertions(+)

Patch
diff mbox series

diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c
index 09165fbef84ed..d51ddcebcca00 100644
--- a/drivers/base/power/opp/core.c
+++ b/drivers/base/power/opp/core.c
@@ -289,6 +289,23 @@  unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
 
+/**
+ * dev_pm_opp_get_max_transition_latency() - Get max transition latency in
+ *					     nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max transition latency, in nanoseconds, to
+ * switch from one OPP to other.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
+{
+	return dev_pm_opp_get_max_volt_latency(dev) +
+		dev_pm_opp_get_max_clock_latency(dev);
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_transition_latency);
+
 /**
  * dev_pm_opp_get_suspend_opp() - Get suspend opp
  * @dev:	device for which we do this operation
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 5daa43058ac10..59da3d9e11ea3 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -35,6 +35,7 @@  bool dev_pm_opp_is_turbo(struct dev_pm_opp *opp);
 int dev_pm_opp_get_opp_count(struct device *dev);
 unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev);
 unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev);
+unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev);
 struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev);
 
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
@@ -94,6 +95,11 @@  static inline unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
 	return 0;
 }
 
+static inline unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev)
+{
+	return 0;
+}
+
 static inline struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
 {
 	return NULL;