[PATCH v10 1/8] opp: Add dev_pm_opp_get_current()

Dmitry Osipenko
2021-08-31T13:57:10Z

Add dev_pm_opp_get_current() helper that returns OPP corresponding
to the current clock rate of a device.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/opp/core.c | 43 +++++++++++++++++++++++++++++++++++++++---
include/linux/pm_opp.h | 6 ++++++
2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 04b4691a8aac..dde8a5cc948c 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -939,7 +939,7 @@ static int _set_required_opps(struct device *dev,
return ret;
}

-static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
+static struct dev_pm_opp *_find_current_opp(struct opp_table *opp_table)
{
struct dev_pm_opp *opp = ERR_PTR(-ENODEV);
unsigned long freq;
@@ -949,6 +949,18 @@ static void _find_current_opp(struct device *dev, struct opp_table *opp_table)
opp = _find_freq_ceil(opp_table, &freq);
}

+ return opp;
+}
+
+static void _find_and_set_current_opp(struct opp_table *opp_table)
+{
+ struct dev_pm_opp *opp;
+
+ if (opp_table->current_opp)
+ return;
+
+ opp = _find_current_opp(opp_table);
+
/*
* Unable to find the current OPP ? Pick the first from the list since
* it is in ascending order, otherwise rest of the code will need to
@@ -1002,8 +1014,7 @@ static int _set_opp(struct device *dev, struct opp_table *opp_table,
return _disable_opp_table(dev, opp_table);

/* Find the currently set OPP if we don't know already */
- if (unlikely(!opp_table->current_opp))
- _find_current_opp(dev, opp_table);
+ _find_and_set_current_opp(opp_table);

old_opp = opp_table->current_opp;

@@ -2931,3 +2942,29 @@ int dev_pm_opp_sync_regulators(struct device *dev)
return ret;
}
EXPORT_SYMBOL_GPL(dev_pm_opp_sync_regulators);
+
+/**
+ * dev_pm_opp_get_current() - Get current OPP
+ * @dev: device for which we do this operation
+ *
+ * Get current OPP of a device based on current clock rate or by other means.
+ *
+ * Return: pointer to 'struct dev_pm_opp' on success and errorno otherwise.
+ */
+struct dev_pm_opp *dev_pm_opp_get_current(struct device *dev)
+{
+ struct opp_table *opp_table;
+ struct dev_pm_opp *opp;
+
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return ERR_CAST(opp_table);
+
+ opp = _find_current_opp(opp_table);
+
+ /* Drop reference taken by _find_opp_table() */
+ dev_pm_opp_put_opp_table(opp_table);
+
+ return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_current);
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 84150a22fd7c..c8091977efb8 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -168,6 +168,7 @@ int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
void dev_pm_opp_remove_table(struct device *dev);
void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask);
int dev_pm_opp_sync_regulators(struct device *dev);
+struct dev_pm_opp *dev_pm_opp_get_current(struct device *dev);
#else
static inline struct opp_table *dev_pm_opp_get_opp_table(struct device *dev)
{
@@ -434,6 +435,11 @@ static inline int dev_pm_opp_sync_regulators(struct device *dev)
return -EOPNOTSUPP;
}

+static inline struct dev_pm_opp *dev_pm_opp_get_current(struct device *dev)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
+
#endif /* CONFIG_PM_OPP */

#if defined(CONFIG_PM_OPP) && defined(CONFIG_OF)
--
2.32.0