You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
154 lines
4.8 KiB
Diff
154 lines
4.8 KiB
Diff
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>
|
|
|
|
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.
|
|
|
|
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>
|
|
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 | 69 ++++++++++++++++++++++++++++++++++++++++++
|
|
include/linux/pm_opp.h | 13 ++++++++
|
|
2 files changed, 82 insertions(+)
|
|
|
|
--- a/drivers/opp/core.c
|
|
+++ b/drivers/opp/core.c
|
|
@@ -2103,6 +2103,75 @@ 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 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.
|
|
+ */
|
|
+int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
|
|
+ unsigned long u_volt, unsigned long u_volt_min,
|
|
+ unsigned long u_volt_max)
|
|
+
|
|
+{
|
|
+ struct opp_table *opp_table;
|
|
+ struct dev_pm_opp *tmp_opp, *opp = ERR_PTR(-ENODEV);
|
|
+ int r = 0;
|
|
+
|
|
+ /* 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);
|
|
+ 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) {
|
|
+ opp = tmp_opp;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ if (IS_ERR(opp)) {
|
|
+ r = PTR_ERR(opp);
|
|
+ goto adjust_unlock;
|
|
+ }
|
|
+
|
|
+ /* Is update really needed? */
|
|
+ if (opp->supplies->u_volt == u_volt)
|
|
+ goto adjust_unlock;
|
|
+
|
|
+ opp->supplies->u_volt = u_volt;
|
|
+ opp->supplies->u_volt_min = u_volt_min;
|
|
+ opp->supplies->u_volt_max = u_volt_max;
|
|
+
|
|
+ dev_pm_opp_get(opp);
|
|
+ mutex_unlock(&opp_table->lock);
|
|
+
|
|
+ /* Notify the voltage change of the OPP */
|
|
+ blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE,
|
|
+ opp);
|
|
+
|
|
+ dev_pm_opp_put(opp);
|
|
+ goto adjust_put_table;
|
|
+
|
|
+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
|
|
--- a/include/linux/pm_opp.h
|
|
+++ b/include/linux/pm_opp.h
|
|
@@ -22,6 +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,
|
|
};
|
|
|
|
/**
|
|
@@ -113,6 +114,10 @@ int dev_pm_opp_add(struct device *dev, u
|
|
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_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);
|
|
@@ -242,6 +247,14 @@ static inline void dev_pm_opp_remove_all
|
|
{
|
|
}
|
|
|
|
+static inline int
|
|
+dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq,
|
|
+ unsigned long u_volt, unsigned long u_volt_min,
|
|
+ unsigned long u_volt_max)
|
|
+{
|
|
+ return 0;
|
|
+}
|
|
+
|
|
static inline int dev_pm_opp_enable(struct device *dev, unsigned long freq)
|
|
{
|
|
return 0;
|