@@ -226,6 +226,65 @@ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
/**
+ * dev_pm_opp_get_max_volt_latency() - Get max voltage latency in nanoseconds
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the max voltage latency in nanoseconds.
+ *
+ * Locking: This function takes rcu_read_lock().
+ */
+unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
+{
+ struct device_opp *dev_opp;
+ struct dev_pm_opp *opp;
+ struct opp_supply *supply;
+ struct regulator *reg;
+ unsigned long latency_ns = 0;
+ unsigned long min_uV, max_uV;
+ int count, ret;
+
+ rcu_read_lock();
+
+ dev_opp = _find_device_opp(dev);
+ if (IS_ERR(dev_opp))
+ goto unlock;
+
+ /* Sum max latencies for all supplies */
+ for (count = 0; count < dev_opp->supply_count; count++) {
+ min_uV = ~0;
+ max_uV = 0;
+
+ reg = dev_opp->regulators[count];
+
+ /* Regulator may not be available for device */
+ if (IS_ERR(reg))
+ continue;
+
+ list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
+ if (!opp->available)
+ continue;
+
+ supply = opp->supplies + count;
+
+ if (supply->u_volt_min < min_uV)
+ min_uV = supply->u_volt_min;
+ if (supply->u_volt_max > max_uV)
+ max_uV = supply->u_volt_max;
+ }
+
+ ret = regulator_set_voltage_time(reg, min_uV, max_uV);
+ if (ret > 0)
+ latency_ns += ret * 1000;
+ }
+
+unlock:
+ rcu_read_unlock();
+
+ return latency_ns;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_volt_latency);
+
+/**
* dev_pm_opp_get_suspend_opp() - Get suspend opp
* @dev: device for which we do this operation
*
@@ -34,6 +34,7 @@ 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);
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,
@@ -81,6 +82,11 @@ static inline unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
return 0;
}
+static inline unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev)
+{
+ return 0;
+}
+
static inline struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
{
return NULL;
In few use cases (like: cpufreq), it is desired to get the maximum voltage latency for changing OPPs. Add support for that. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/base/power/opp/core.c | 59 +++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_opp.h | 6 +++++ 2 files changed, 65 insertions(+)