[PATCH 2/2] opp: core: add regulators enable and disable

From: Viresh Kumar
Date: Fri May 15 2020 - 03:57:39 EST


From: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>

Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). Even if bootloader
leaves regulators enabled, they should be enabled in kernel in
order to increase the reference count.

Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
[ Viresh: Enable the regulator only after it is programmed and add a
flag to track its status. ]
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/opp/core.c | 28 ++++++++++++++++++++++++++--
drivers/opp/opp.h | 2 ++
2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index dda8164fad56..da6533d5526f 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -664,7 +664,7 @@ static inline int _generic_set_opp_clk_only(struct device *dev, struct clk *clk,
return ret;
}

-static int _generic_set_opp_regulator(const struct opp_table *opp_table,
+static int _generic_set_opp_regulator(struct opp_table *opp_table,
struct device *dev,
unsigned long old_freq,
unsigned long freq,
@@ -699,6 +699,18 @@ static int _generic_set_opp_regulator(const struct opp_table *opp_table,
goto restore_freq;
}

+ /*
+ * Enable the regulator after setting its voltages, otherwise it breaks
+ * some boot-enabled regulators.
+ */
+ if (unlikely(!opp_table->regulator_enabled)) {
+ ret = regulator_enable(reg);
+ if (ret < 0)
+ dev_warn(dev, "Failed to enable regulator: %d", ret);
+ else
+ opp_table->regulator_enabled = true;
+ }
+
return 0;

restore_freq:
@@ -825,11 +837,16 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq)
if (!_get_opp_count(opp_table))
return 0;

- if (!opp_table->required_opp_tables) {
+ if (!opp_table->required_opp_tables && !opp_table->regulators) {
dev_err(dev, "target frequency can't be 0\n");
ret = -EINVAL;
}

+ if (opp_table->regulator_enabled) {
+ regulator_disable(opp_table->regulators[0]);
+ opp_table->regulator_enabled = false;
+ }
+
ret = _set_required_opps(dev, opp_table, NULL);
goto put_opp_table;
}
@@ -1675,6 +1692,13 @@ void dev_pm_opp_put_regulators(struct opp_table *opp_table)
/* Make sure there are no concurrent readers while updating opp_table */
WARN_ON(!list_empty(&opp_table->opp_list));

+ if (opp_table->regulator_enabled) {
+ for (i = opp_table->regulator_count - 1; i >= 0; i--)
+ regulator_disable(opp_table->regulators[i]);
+
+ opp_table->regulator_enabled = false;
+ }
+
for (i = opp_table->regulator_count - 1; i >= 0; i--)
regulator_put(opp_table->regulators[i]);

diff --git a/drivers/opp/opp.h b/drivers/opp/opp.h
index d14e27102730..b4b2713d84f1 100644
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -144,6 +144,7 @@ enum opp_table_access {
* @clk: Device's clock handle
* @regulators: Supply regulators
* @regulator_count: Number of power supply regulators. Its value can be -1
+ * @regulator_enabled: Set to true if regulators were previously enabled.
* (uninitialized), 0 (no opp-microvolt property) or > 0 (has opp-microvolt
* property).
* @genpd_performance_state: Device's power domain support performance state.
@@ -189,6 +190,7 @@ struct opp_table {
struct clk *clk;
struct regulator **regulators;
int regulator_count;
+ bool regulator_enabled;
bool genpd_performance_state;
bool is_genpd;

--
2.25.0.rc1.19.g042ed3e048af