diff options
Diffstat (limited to 'target/linux/ipq806x/patches-4.14/0049-PM-OPP-Support-adjusting-OPP-voltages-at-runtime.patch')
| -rw-r--r-- | target/linux/ipq806x/patches-4.14/0049-PM-OPP-Support-adjusting-OPP-voltages-at-runtime.patch | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/target/linux/ipq806x/patches-4.14/0049-PM-OPP-Support-adjusting-OPP-voltages-at-runtime.patch b/target/linux/ipq806x/patches-4.14/0049-PM-OPP-Support-adjusting-OPP-voltages-at-runtime.patch new file mode 100644 index 0000000000..2ab46e176e --- /dev/null +++ b/target/linux/ipq806x/patches-4.14/0049-PM-OPP-Support-adjusting-OPP-voltages-at-runtime.patch @@ -0,0 +1,147 @@ +From c949f08cf20fe82971fbdb4015daa38210da492e Mon Sep 17 00:00:00 2001 +From: Stephen Boyd <sboyd@codeaurora.org> +Date: Fri, 18 Sep 2015 17:52:06 -0700 +Subject: [PATCH 49/69] PM / OPP: Support adjusting OPP voltages at runtime + +On some SoCs the Adaptive Voltage Scaling (AVS) technique is +employed to optimize the operating voltage of a device. At a +given frequency, the hardware monitors dynamic factors and either +makes a suggestion for how much to adjust a voltage for the +current frequency, or it automatically adjusts the voltage +without software intervention. Add an API to the OPP library for +the former case, so that AVS type devices can update the voltages +for an OPP when the hardware determines the voltage should +change. The assumption is that drivers like CPUfreq or devfreq +will register for the OPP notifiers and adjust the voltage +according to suggestions that AVS makes. + +Cc: Nishanth Menon <nm@ti.com> +Acked-by: Viresh Kumar <viresh.kumar@linaro.org> +Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> +Acked-by: Viresh Kumar <viresh.kumar@linaro.org> +Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org> +--- + drivers/base/power/opp/core.c | 77 +++++++++++++++++++++++++++++++++++++++++++ + include/linux/pm_opp.h | 11 +++++++ + 2 files changed, 88 insertions(+) + +--- a/drivers/base/power/opp/core.c ++++ b/drivers/base/power/opp/core.c +@@ -1605,6 +1605,83 @@ unlock: + } + + /** ++ * dev_pm_opp_adjust_voltage() - helper to change the voltage of an OPP ++ * @dev: device for which we do this operation ++ * @freq: OPP frequency to adjust voltage of ++ * @u_volt: new OPP voltage ++ * ++ * Change the voltage of an OPP with an RCU operation. ++ * ++ * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the ++ * copy operation, returns 0 if no modifcation was done OR modification was ++ * successful. ++ * ++ * Locking: The internal device_opp and opp structures are RCU protected. ++ * Hence this function internally uses RCU updater strategy with mutex locks to ++ * keep the integrity of the internal data structures. Callers should ensure ++ * that this function is *NOT* called under RCU protection or in contexts where ++ * mutex locking or synchronize_rcu() blocking calls cannot be used. ++ */ ++int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq, ++ unsigned long u_volt) ++{ ++ struct opp_table *opp_table; ++ struct dev_pm_opp *new_opp, *tmp_opp, *opp = ERR_PTR(-ENODEV); ++ int r = 0; ++ ++ /* keep the node allocated */ ++ new_opp = kmalloc(sizeof(*new_opp), GFP_KERNEL); ++ if (!new_opp) ++ return -ENOMEM; ++ ++ mutex_lock(&opp_table_lock); ++ ++ /* Find the opp_table */ ++ opp_table = _find_opp_table(dev); ++ if (IS_ERR(opp_table)) { ++ r = PTR_ERR(opp_table); ++ dev_warn(dev, "%s: Device OPP not found (%d)\n", __func__, r); ++ goto unlock; ++ } ++ ++ /* Do we have the frequency? */ ++ list_for_each_entry(tmp_opp, &opp_table->opp_list, node) { ++ if (tmp_opp->rate == freq) { ++ opp = tmp_opp; ++ break; ++ } ++ } ++ if (IS_ERR(opp)) { ++ r = PTR_ERR(opp); ++ goto unlock; ++ } ++ ++ /* Is update really needed? */ ++ if (opp->supplies[0].u_volt == u_volt) ++ goto unlock; ++ /* copy the old data over */ ++ *new_opp = *opp; ++ ++ /* plug in new node */ ++ new_opp->supplies[0].u_volt = u_volt; ++ ++ list_replace(&opp->node, &new_opp->node); ++ mutex_unlock(&opp_table_lock); ++ kfree(opp); ++ ++ /* Notify the change of the OPP */ ++ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE, ++ new_opp); ++ ++ return 0; ++ ++unlock: ++ mutex_unlock(&opp_table_lock); ++ kfree(new_opp); ++ return r; ++} ++ ++/** + * dev_pm_opp_enable() - Enable a specific OPP + * @dev: device for which we do this operation + * @freq: OPP frequency to enable +--- a/include/linux/pm_opp.h ++++ b/include/linux/pm_opp.h +@@ -25,6 +25,7 @@ struct opp_table; + + enum dev_pm_opp_event { + OPP_EVENT_ADD, OPP_EVENT_REMOVE, OPP_EVENT_ENABLE, OPP_EVENT_DISABLE, ++ OPP_EVENT_ADJUST_VOLTAGE, + }; + + /** +@@ -108,6 +109,9 @@ int dev_pm_opp_add(struct device *dev, u + unsigned long u_volt); + void dev_pm_opp_remove(struct device *dev, unsigned long freq); + ++int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq, ++ unsigned long u_volt); ++ + int dev_pm_opp_enable(struct device *dev, unsigned long freq); + + int dev_pm_opp_disable(struct device *dev, unsigned long freq); +@@ -208,6 +212,13 @@ static inline void dev_pm_opp_remove(str + { + } + ++static inline int ++dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq, ++ unsigned long u_volt) ++{ ++ return 0; ++} ++ + static inline int dev_pm_opp_enable(struct device *dev, unsigned long freq) + { + return 0; |