PM / OPP: Introduce dev_pm_opp_get_max_volt_latency()

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>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2016-02-09 10:30:35 +05:30 committed by Rafael J. Wysocki
parent 7d34d56ef3
commit 655c9df961
2 changed files with 65 additions and 0 deletions

View File

@ -230,6 +230,65 @@ 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 regulator *reg;
unsigned long latency_ns = 0;
unsigned long min_uV = ~0, max_uV = 0;
int ret;
rcu_read_lock();
dev_opp = _find_device_opp(dev);
if (IS_ERR(dev_opp)) {
rcu_read_unlock();
return 0;
}
reg = dev_opp->regulator;
if (IS_ERR_OR_NULL(reg)) {
/* Regulator may not be required for device */
if (reg)
dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__,
PTR_ERR(reg));
rcu_read_unlock();
return 0;
}
list_for_each_entry_rcu(opp, &dev_opp->opp_list, node) {
if (!opp->available)
continue;
if (opp->u_volt_min < min_uV)
min_uV = opp->u_volt_min;
if (opp->u_volt_max > max_uV)
max_uV = opp->u_volt_max;
}
rcu_read_unlock();
/*
* The caller needs to ensure that dev_opp (and hence the regulator)
* isn't freed, while we are executing this routine.
*/
ret = regulator_set_voltage_time(reg, min_uV, max_uV);
if (ret > 0)
latency_ns = ret * 1000;
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

View File

@ -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,
@ -88,6 +89,11 @@ 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;