+++ /dev/null
-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
-@@ -1608,6 +1608,83 @@ put_table:
- }
-
- /**
-+ * 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;
projects / openwrt / openwrt.git / blobdiff