[PATCH v4 04/12] OPP: Add and export helper to update voltage

Sibi Sankar
2020-05-04T20:24:22Z

Add and export 'dev_pm_opp_update_voltage' to update the voltage of an
opp for a given frequency. This will be useful to update the opps with
voltages read back from firmware.

Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
---

v4:
* Function description update [Matthias]
* Drop initialization [Matthias]
* Drop err message on opp_table get failure

drivers/opp/core.c | 51 ++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_opp.h | 10 +++++++++
2 files changed, 61 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index cfad09f5dfffa..7f7060079bb28 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -2248,6 +2248,57 @@ int dev_pm_opp_disable(struct device *dev, unsigned long freq)
}
EXPORT_SYMBOL_GPL(dev_pm_opp_disable);

+/**
+ * dev_pm_opp_update_voltage() - Update the voltage of an opp
+ * @dev: device for which we do this operation
+ * @freq: OPP frequency to update voltage
+ * @u_volt: voltage requested for this opp
+ *
+ * Update voltage of a disabled opp corresponding to the given frequency.
+ * This is useful only for devices with single power supply.
+ *
+ * Return: 0 if modification was successful or a negative error value.
+ */
+int dev_pm_opp_update_voltage(struct device *dev, unsigned long freq,
+ unsigned long u_volt)
+{
+ struct opp_table *opp_table;
+ struct dev_pm_opp *opp;
+ unsigned long tol;
+ int ret = 0;
+
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return PTR_ERR(opp_table);
+
+ opp = dev_pm_opp_find_freq_exact(dev, freq, false);
+ if (IS_ERR(opp)) {
+ ret = PTR_ERR(opp);
+ goto put_table;
+ }
+
+ mutex_lock(&opp_table->lock);
+
+ /* update only if the opp is disabled */
+ if (opp->available) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
+ opp->supplies[0].u_volt_min = u_volt - tol;
+ opp->supplies[0].u_volt = u_volt;
+ opp->supplies[0].u_volt_min = u_volt + tol;
+
+unlock:
+ mutex_unlock(&opp_table->lock);
+ dev_pm_opp_put(opp);
+put_table:
+ dev_pm_opp_put_opp_table(opp_table);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_update_voltage);
+
/**
* dev_pm_opp_register_notifier() - Register OPP notifier for the device
* @dev: Device for which notifier needs to be registered
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index cfceb02904018..639bc0382ee02 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -134,6 +134,9 @@ int dev_pm_opp_enable(struct device *dev, unsigned long freq);

int dev_pm_opp_disable(struct device *dev, unsigned long freq);

+int dev_pm_opp_update_voltage(struct device *dev, unsigned long freq,
+ unsigned long u_volt);
+
int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb);
int dev_pm_opp_unregister_notifier(struct device *dev, struct notifier_block *nb);

@@ -277,6 +280,13 @@ static inline int dev_pm_opp_disable(struct device *dev, unsigned long freq)
return 0;
}

+static inline int dev_pm_opp_update_voltage(struct device *dev,
+ unsigned long freq,
+ unsigned long u_volt)
+{
+ return 0;
+}
+
static inline int dev_pm_opp_register_notifier(struct device *dev, struct notifier_block *nb)
{
return -ENOTSUPP;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project