+++ /dev/null
-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
-@@ -2102,6 +2102,75 @@ 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;
projects / openwrt / openwrt.git / blobdiff