PM / OPP: Update voltage in case freq == old_freq

[mirror_ubuntu-bionic-kernel.git] / drivers / opp / core.c

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 92fa94a6dcc111ab168056235e2c7f6acdb8a5a3..d446e1540f05a1abdd22b92c9ca575761a7fbc0e 100644 (file)
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -127,6 +127,27 @@ unsigned long dev_pm_opp_get_freq(struct dev_pm_opp *opp)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_freq);
 
+struct regulator *dev_pm_opp_get_regulator(struct device *dev)
+{
+       struct opp_table *opp_table;
+       struct regulator *reg;
+
+       rcu_read_lock();
+
+       opp_table = _find_opp_table(dev);
+       if (IS_ERR(opp_table)) {
+               rcu_read_unlock();
+               return ERR_CAST(opp_table);
+       }
+
+       reg = opp_table->regulators[0];
+
+       rcu_read_unlock();
+
+       return reg;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_regulator);
+
 /**
  * dev_pm_opp_is_turbo() - Returns if opp is turbo OPP or not
  * @opp: opp for which turbo mode is being verified
@@ -591,7 +612,7 @@ static int _generic_set_opp_regulator(const struct opp_table *opp_table,
        }
 
        /* Scaling up? Scale voltage before frequency */
-       if (freq > old_freq) {
+       if (freq >= old_freq) {
                ret = _set_opp_voltage(dev, reg, new_supply);
                if (ret)
                        goto restore_voltage;
@@ -1328,11 +1349,13 @@ struct opp_table *dev_pm_opp_set_regulators(struct device *dev,
        if (!opp_table)
                return ERR_PTR(-ENOMEM);
 
+#if 0
        /* This should be called before OPPs are initialized */
        if (WARN_ON(!list_empty(&opp_table->opp_list))) {
                ret = -EBUSY;
                goto err;
        }
+#endif
 
        /* Already have regulators set */
        if (opp_table->regulators) {
@@ -1728,6 +1751,76 @@ put_table:
        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.
+ *
+ * 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 *tmp_opp, *opp = ERR_PTR(-ENODEV);
+       int r = 0;
+       unsigned long tol;
+
+       mutex_lock(&opp_table_lock);
+
+       /* Find the opp_table */
+       opp_table = _find_opp_table_unlocked(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;
+
+       /* adjust voltage node */
+       tol = u_volt * opp_table->voltage_tolerance_v1 / 100;
+       opp->supplies[0].u_volt = u_volt;
+       opp->supplies[0].u_volt_min = u_volt - tol;
+       opp->supplies[0].u_volt_max = u_volt + tol;
+
+       mutex_unlock(&opp_table_lock);
+
+       /* Notify the change of the OPP */
+       blocking_notifier_call_chain(&opp_table->head, OPP_EVENT_ADJUST_VOLTAGE, opp);
+
+       return 0;
+
+unlock:
+       mutex_unlock(&opp_table_lock);
+       return r;
+}
+
 /**
  * dev_pm_opp_enable() - Enable a specific OPP
  * @dev:       device for which we do this operation