[PATCH 2/4] OPP: Add support for parsing the 'opp-sustainable' property

Lukasz Luba
2020-10-28T22:28:53Z

Now that the OPP bindings are updated to include an optional
'opp-sustainable' property, add support to parse it from device tree and
store it as part of dev_pm_opp structure.
Also add and export an helper 'dev_pm_opp_get_sustainable()' that can be
used to get the sustainable OPP when present.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
drivers/opp/core.c | 26 ++++++++++++++++++++++++++
drivers/opp/of.c | 14 ++++++++++++++
drivers/opp/opp.h | 3 +++
include/linux/pm_opp.h | 6 ++++++
4 files changed, 49 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 9915e8487f0b..bb1e68b96d0e 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -299,6 +299,32 @@ unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
}
EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp_freq);

+/**
+ * dev_pm_opp_get_sustainable_opp_freq() - Get frequency of sustainable opp
+ * in Hz
+ * @dev: device for which we do this operation
+ *
+ * Return: This function returns the frequency of the OPP marked as
+ * sustainable_opp if one is available, else returns 0;
+ */
+unsigned long dev_pm_opp_get_sustainable_opp_freq(struct device *dev)
+{
+ struct opp_table *opp_table;
+ unsigned long freq = 0;
+
+ opp_table = _find_opp_table(dev);
+ if (IS_ERR(opp_table))
+ return 0;
+
+ if (opp_table->sustainable_opp && opp_table->sustainable_opp->available)
+ freq = dev_pm_opp_get_freq(opp_table->sustainable_opp);
+
+ dev_pm_opp_put_opp_table(opp_table);
+
+ return freq;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_sustainable_opp_freq);
+
int _get_opp_count(struct opp_table *opp_table)
{
struct dev_pm_opp *opp;
diff --git a/drivers/opp/of.c b/drivers/opp/of.c
index 9faeb83e4b32..1f6b19bb1a95 100644
--- a/drivers/opp/of.c
+++ b/drivers/opp/of.c
@@ -815,6 +815,20 @@ static struct dev_pm_opp *_opp_add_static_v2(struct opp_table *opp_table,
}
}

+ if (of_property_read_bool(np, "opp-sustainable")) {
+ if (opp_table->sustainable_opp) {
+ /* Pick the OPP with higher rate as sustainable OPP */
+ if (new_opp->rate > opp_table->sustainable_opp->rate) {
+ opp_table->sustainable_opp->sustainable = false;
+ new_opp->sustainable = true;
+ opp_table->sustainable_opp = new_opp;
+ }
+ } else {
+ new_opp->sustainable = true;
+ opp_table->sustainable_opp = new_opp;
+ }
+ }
+
if (new_opp->clock_latency_ns > opp_table->clock_latency_ns_max)
opp_table->clock_latency_ns_max = new_opp->clock_latency_ns;

diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index ebd930e0b3ca..45288ccbb295 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -56,6 +56,7 @@ extern struct list_head opp_tables;
* @dynamic: not-created from static DT entries.
* @turbo: true if turbo (boost) OPP
* @suspend: true if suspend OPP
+ * @sustainable: true if sustainable OPP
* @pstate: Device's power domain's performance state.
* @rate: Frequency in hertz
* @level: Performance level
@@ -78,6 +79,7 @@ struct dev_pm_opp {
bool dynamic;
bool turbo;
bool suspend;
+ bool sustainable;
unsigned int pstate;
unsigned long rate;
unsigned int level;
@@ -183,6 +185,7 @@ struct opp_table {
unsigned int parsed_static_opps;
enum opp_table_access shared_opp;
struct dev_pm_opp *suspend_opp;
+ struct dev_pm_opp *sustainable_opp;

struct mutex genpd_virt_dev_lock;
struct device **genpd_virt_devs;
diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index dbb484524f82..363d5a2c1ef3 100644
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -106,6 +106,7 @@ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev);
unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev);
unsigned long dev_pm_opp_get_max_transition_latency(struct device *dev);
unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev);
+unsigned long dev_pm_opp_get_sustainable_opp_freq(struct device *dev);

struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
unsigned long freq,
@@ -215,6 +216,11 @@ static inline unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev)
return 0;
}

+static inline unsigned long dev_pm_opp_get_sustainable_opp_freq(struct device *dev)
+{
+ return 0;
+}
+
static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
unsigned long freq, bool available)
{
--
2.17.1