opp: core: add regulators enable and disable

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.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Clément Péron <peron.clem@gmail.com>
Tested-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
[ Viresh: Enable the regulator only after it is programmed and add a
	  flag to track its status. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 5e1035a..8efe12a 100644 (file)
--- 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:
@@ -825,12 +837,17 @@ 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;
                        goto put_opp_table;
                }
 
+               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;
        }
@@ -1718,6 +1735,13 @@ 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 2b81ffe..e51646f 100644 (file)
--- a/drivers/opp/opp.h
+++ b/drivers/opp/opp.h
@@ -147,6 +147,7 @@ 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).
  * @paths: Interconnect path handles
@@ -194,6 +195,7 @@ struct opp_table {
        struct clk *clk;
        struct regulator **regulators;
        int regulator_count;
+       bool regulator_enabled;
        struct icc_path **paths;
        unsigned int path_count;
        bool genpd_performance_state;