@ -1,7 +1,17 @@
From c949f08cf20fe82971fbdb4015daa38210da492e Mon Sep 17 00:00:00 2001
From: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: krzk@kernel.org, vireshk@kernel.org, robh+dt@kernel.org
Cc: sboyd@kernel.org, roger.lu@mediatek.com,
linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, devicetree@vger.kernel.org,
b.zolnierkie@samsung.com, m.szyprowski@samsung.com,
Stephen Boyd <sboyd@codeaurora.org>,
Sylwester Nawrocki <s.nawrocki@samsung.com>
Subject: [PATCH v5 1/4] PM / OPP: Support adjusting OPP voltages at runtime
Date: Wed, 16 Oct 2019 16:57:53 +0200
Message-ID: <20191016145756.16004-2-s.nawrocki@samsung.com> (raw)
In-Reply-To: <20191016145756.16004-1-s.nawrocki@samsung.com>
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
@ -15,61 +25,57 @@ 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>
This patch is derived from [1] submitted by Stephen.
[1] https://lore.kernel.org/patchwork/patch/599279/
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>
Signed-off-by: Roger Lu <roger.lu@mediatek.com>
[s.nawrocki@samsung.com: added handling of OPP min/max voltage]
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
---
drivers/opp/core.c | 77 + ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 11 +++++++
2 files changed, 88 insertions(+)
drivers/opp/core.c | 69 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 13 + +++++++
2 files changed, 82 insertions(+)
diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 3b7ffd0234e9..f38b3be85072 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -1625,6 +1625,83 @@ put_table:
@@ -2112,6 +2112,75 @@ static int _opp_set_availability(struct device *dev, unsigned long freq,
return r;
}
/**
+/**
+ * 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.
+ * @u_volt: new OPP target voltage
+ * @u_volt_min: new OPP min voltage
+ * @u_volt_max: new OPP max voltage
+ *
+ * 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)
+ unsigned long u_volt, unsigned long u_volt_min,
+ unsigned long u_volt_max)
+
+{
+ struct opp_table *opp_table;
+ struct dev_pm_opp * new_opp, * tmp_opp, *opp = ERR_PTR(-ENODEV);
+ struct dev_pm_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 ;
+ return r;
+ }
+
+ mutex_lock(&opp_table->lock);
+
+ /* Do we have the frequency? */
+ list_for_each_entry(tmp_opp, &opp_table->opp_list, node) {
+ if (tmp_opp->rate == freq) {
@ -77,67 +83,71 @@ Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
+ break;
+ }
+ }
+
+ if (IS_ERR(opp)) {
+ r = PTR_ERR(opp);
+ goto unlock;
+ goto adjust_ unlock;
+ }
+
+ /* Is update really needed? */
+ if (opp->supplies[0].u_volt == u_volt)
+ goto unlock;
+ /* copy the old data over */
+ *new_opp = *opp;
+ if (opp->supplies->u_volt == u_volt)
+ goto adjust_unlock;
+
+ /* plug in new node */
+ new_opp->supplies[0].u_volt = u_volt;
+ opp->supplies->u_volt = u_volt;
+ opp->supplies->u_volt_min = u_volt_min;
+ opp->supplies->u_volt_max = u_volt_max;
+
+ list_replace(&opp->node, &new_opp->node);
+ mutex_unlock(&opp_table_lock);
+ kfree(opp);
+ dev_pm_opp_get(opp);
+ mutex_unlock(&opp_table->lock);
+
+ /* Notify the change of the OPP */
+ /* Notify the voltage change of the OPP */
+ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE,
+ new_ opp);
+ opp);
+
+ return 0;
+ dev_pm_opp_put(opp);
+ goto adjust_put_table;
+
+unlock:
+ mutex_unlock(&opp_table_lock);
+ kfree(new_opp);
+adjust_unlock:
+ mutex_unlock(&opp_table->lock);
+adjust_put_table:
+ dev_pm_opp_put_opp_table(opp_table);
+ return r;
+}
+
+/**
/**
* dev_pm_opp_enable() - Enable a specific OPP
* @dev: device for which we do this operation
* @freq: OPP frequency to enable
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index b8197ab014f2..747861816f4f 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -2 5,6 +25 ,7 @@ struct opp_table;
@@ -2 2,6 +22 ,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);
@@ -113,6 +114,10 @@ int dev_pm_opp_add(struct device *dev, unsigned long freq,
void dev_pm_opp_remove(struct device *dev, unsigned long freq);
void dev_pm_opp_remove_all_dynamic(struct device *dev);
+int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
+ unsigned long u_volt);
+ unsigned long u_volt, unsigned long u_volt_min,
+ unsigned long u_volt_max);
+
int dev_pm_opp_enable(struct device *dev, unsigned long freq);
int dev_pm_opp_disable(struct device *dev, unsigned long freq);
@@ -2 08,6 +212,13 @@ static inline void dev_pm_opp_remove(str
@@ -2 42,6 +247,14 @@ static inline void dev_pm_opp_remove_all_dynamic(struct device *dev)
{
}
+static inline int
+dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
+ unsigned long u_volt)
+ unsigned long u_volt, unsigned long u_volt_min,
+ unsigned long u_volt_max)
+{
+ return 0;
+}
Ansuel Smith
4 years ago
committed by
Petr Štetiar