With "operating-points-v2" bindings, clock-latency is defined per OPP. Users of this value expect a single value which defines the latency to switch to any clock rate. Find maximum clock-latency-ns from the OPP table to service requests from such users.
Reviewed-by: Stephen Boyd sboyd@codeaurora.org Reviewed-by: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/base/power/opp.c | 41 +++++++++++++++++++++++++++++++++++++++-- include/linux/pm_opp.h | 6 ++++++ 2 files changed, 45 insertions(+), 2 deletions(-)
diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c index 0e0eff4d9299..8638204c457e 100644 --- a/drivers/base/power/opp.c +++ b/drivers/base/power/opp.c @@ -57,6 +57,8 @@ * @u_volt_min: Minimum voltage in microvolts corresponding to this OPP * @u_volt_max: Maximum voltage in microvolts corresponding to this OPP * @u_amp: Maximum current drawn by the device in microamperes + * @clock_latency_ns: Latency (in nanoseconds) of switching to this OPP's + * frequency from any other OPP's frequency. * @dev_opp: points back to the device_opp struct this opp belongs to * @rcu_head: RCU callback head used for deferred freeing * @np: OPP's device node. @@ -75,6 +77,7 @@ struct dev_pm_opp { unsigned long u_volt_min; unsigned long u_volt_max; unsigned long u_amp; + unsigned long clock_latency_ns;
struct device_opp *dev_opp; struct rcu_head rcu_head; @@ -109,6 +112,8 @@ struct device_opp { struct srcu_notifier_head srcu_head; struct rcu_head rcu_head; struct list_head opp_list; + + unsigned long clock_latency_ns_max; };
/* @@ -226,6 +231,32 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp) EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
/** + * dev_pm_opp_get_max_clock_latency() - Get max clock latency in nanoseconds + * @dev: device for which we do this operation + * + * Return: This function returns the max clock latency in nanoseconds. + * + * Locking: This function takes rcu_read_lock(). + */ +unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev) +{ + struct device_opp *dev_opp; + unsigned long clock_latency_ns; + + rcu_read_lock(); + + dev_opp = _find_device_opp(dev); + if (IS_ERR(dev_opp)) + clock_latency_ns = 0; + else + clock_latency_ns = dev_opp->clock_latency_ns_max; + + rcu_read_unlock(); + return clock_latency_ns; +} +EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency); + +/** * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list * @dev: device for which we do this operation * @@ -779,6 +810,8 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) new_opp->np = np; new_opp->dynamic = false; new_opp->available = true; + of_property_read_u32(np, "clock-latency-ns", + (u32 *)&new_opp->clock_latency_ns);
ret = opp_get_microvolt(new_opp, dev); if (ret) @@ -790,11 +823,15 @@ static int _opp_add_static_v2(struct device *dev, struct device_node *np) if (ret) goto free_opp;
+ if (new_opp->clock_latency_ns > dev_opp->clock_latency_ns_max) + dev_opp->clock_latency_ns_max = new_opp->clock_latency_ns; + mutex_unlock(&dev_opp_list_lock);
- pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu\n", + pr_debug("%s: turbo:%d rate:%lu uv:%lu uvmin:%lu uvmax:%lu latency:%lu\n", __func__, new_opp->turbo, new_opp->rate, new_opp->u_volt, - new_opp->u_volt_min, new_opp->u_volt_max); + new_opp->u_volt_min, new_opp->u_volt_max, + new_opp->clock_latency_ns);
/* * Notify the changes in the availability of the operable diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h index cec2d4540914..20324b579adc 100644 --- a/include/linux/pm_opp.h +++ b/include/linux/pm_opp.h @@ -31,6 +31,7 @@ unsigned long dev_pm_opp_get_voltage(struct dev_pm_opp *opp); unsigned long dev_pm_opp_get_freq(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);
struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, unsigned long freq, @@ -67,6 +68,11 @@ static inline int dev_pm_opp_get_opp_count(struct device *dev) return 0; }
+static inline unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev) +{ + return 0; +} + static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, unsigned long freq, bool available) {