PM / devfreq: exynos-bus: Convert to use dev_pm_opp_set_rate()

Reuse opp core code for setting bus clock and voltage. As a side
effect this allow usage of coupled regulators feature (required
for boards using Exynos5422/5800 SoCs) because dev_pm_opp_set_rate()
uses regulator_set_voltage_triplet() for setting regulator voltage
while the old code used regulator_set_voltage_tol() with fixed
tolerance. This patch also removes no longer needed parsing of DT
property "exynos,voltage-tolerance" (no Exynos devfreq DT node uses
it). After applying changes both functions exynos_bus_passive_target()
and exynos_bus_target() have the same code, so remove
exynos_bus_passive_target(). In exynos_bus_probe() replace it with
exynos_bus_target.

Signed-off-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/exynos-bus.c b/drivers/devfreq/exynos-bus.c
index 7c06df8bd74fe3df16c490e530e31cc710dec2e6..c832673273a28daa7413fac8bb770eb8af0c4ca1 100644 (file)
--- a/drivers/devfreq/exynos-bus.c
+++ b/drivers/devfreq/exynos-bus.c
@@ -22,7 +22,6 @@
 #include <linux/slab.h>
 
 #define DEFAULT_SATURATION_RATIO       40
-#define DEFAULT_VOLTAGE_TOLERANCE      2
 
 struct exynos_bus {
        struct device *dev;
@@ -34,9 +33,8 @@ struct exynos_bus {
 
        unsigned long curr_freq;
 
-       struct regulator *regulator;
+       struct opp_table *opp_table;
        struct clk *clk;
-       unsigned int voltage_tolerance;
        unsigned int ratio;
 };
 
@@ -90,62 +88,29 @@ static int exynos_bus_get_event(struct exynos_bus *bus,
 }
 
 /*
- * Must necessary function for devfreq simple-ondemand governor
+ * devfreq function for both simple-ondemand and passive governor
  */
 static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
 {
        struct exynos_bus *bus = dev_get_drvdata(dev);
        struct dev_pm_opp *new_opp;
-       unsigned long old_freq, new_freq, new_volt, tol;
        int ret = 0;
 
-       /* Get new opp-bus instance according to new bus clock */
+       /* Get correct frequency for bus. */
        new_opp = devfreq_recommended_opp(dev, freq, flags);
        if (IS_ERR(new_opp)) {
                dev_err(dev, "failed to get recommended opp instance\n");
                return PTR_ERR(new_opp);
        }
 
-       new_freq = dev_pm_opp_get_freq(new_opp);
-       new_volt = dev_pm_opp_get_voltage(new_opp);
        dev_pm_opp_put(new_opp);
 
-       old_freq = bus->curr_freq;
-
-       if (old_freq == new_freq)
-               return 0;
-       tol = new_volt * bus->voltage_tolerance / 100;
-
        /* Change voltage and frequency according to new OPP level */
        mutex_lock(&bus->lock);
+       ret = dev_pm_opp_set_rate(dev, *freq);
+       if (!ret)
+               bus->curr_freq = *freq;
 
-       if (old_freq < new_freq) {
-               ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
-               if (ret < 0) {
-                       dev_err(bus->dev, "failed to set voltage\n");
-                       goto out;
-               }
-       }
-
-       ret = clk_set_rate(bus->clk, new_freq);
-       if (ret < 0) {
-               dev_err(dev, "failed to change clock of bus\n");
-               clk_set_rate(bus->clk, old_freq);
-               goto out;
-       }
-
-       if (old_freq > new_freq) {
-               ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
-               if (ret < 0) {
-                       dev_err(bus->dev, "failed to set voltage\n");
-                       goto out;
-               }
-       }
-       bus->curr_freq = new_freq;
-
-       dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
-                       old_freq, new_freq, clk_get_rate(bus->clk));
-out:
        mutex_unlock(&bus->lock);
 
        return ret;
@@ -193,54 +158,10 @@ static void exynos_bus_exit(struct device *dev)
 
        dev_pm_opp_of_remove_table(dev);
        clk_disable_unprepare(bus->clk);
-       if (bus->regulator)
-               regulator_disable(bus->regulator);
-}
-
-/*
- * Must necessary function for devfreq passive governor
- */
-static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
-                                       u32 flags)
-{
-       struct exynos_bus *bus = dev_get_drvdata(dev);
-       struct dev_pm_opp *new_opp;
-       unsigned long old_freq, new_freq;
-       int ret = 0;
-
-       /* Get new opp-bus instance according to new bus clock */
-       new_opp = devfreq_recommended_opp(dev, freq, flags);
-       if (IS_ERR(new_opp)) {
-               dev_err(dev, "failed to get recommended opp instance\n");
-               return PTR_ERR(new_opp);
-       }
-
-       new_freq = dev_pm_opp_get_freq(new_opp);
-       dev_pm_opp_put(new_opp);
-
-       old_freq = bus->curr_freq;
-
-       if (old_freq == new_freq)
-               return 0;
-
-       /* Change the frequency according to new OPP level */
-       mutex_lock(&bus->lock);
-
-       ret = clk_set_rate(bus->clk, new_freq);
-       if (ret < 0) {
-               dev_err(dev, "failed to set the clock of bus\n");
-               goto out;
+       if (bus->opp_table) {
+               dev_pm_opp_put_regulators(bus->opp_table);
+               bus->opp_table = NULL;
        }
-
-       *freq = new_freq;
-       bus->curr_freq = new_freq;
-
-       dev_dbg(dev, "Set the frequency of bus (%luHz -> %luHz, %luHz)\n",
-                       old_freq, new_freq, clk_get_rate(bus->clk));
-out:
-       mutex_unlock(&bus->lock);
-
-       return ret;
 }
 
 static void exynos_bus_passive_exit(struct device *dev)
@@ -255,21 +176,19 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
                                        struct exynos_bus *bus)
 {
        struct device *dev = bus->dev;
+       struct opp_table *opp_table;
+       const char *vdd = "vdd";
        int i, ret, count, size;
 
-       /* Get the regulator to provide each bus with the power */
-       bus->regulator = devm_regulator_get(dev, "vdd");
-       if (IS_ERR(bus->regulator)) {
-               dev_err(dev, "failed to get VDD regulator\n");
-               return PTR_ERR(bus->regulator);
-       }
-
-       ret = regulator_enable(bus->regulator);
-       if (ret < 0) {
-               dev_err(dev, "failed to enable VDD regulator\n");
+       opp_table = dev_pm_opp_set_regulators(dev, &vdd, 1);
+       if (IS_ERR(opp_table)) {
+               ret = PTR_ERR(opp_table);
+               dev_err(dev, "failed to set regulators %d\n", ret);
                return ret;
        }
 
+       bus->opp_table = opp_table;
+
        /*
         * Get the devfreq-event devices to get the current utilization of
         * buses. This raw data will be used in devfreq ondemand governor.
@@ -310,14 +229,11 @@ static int exynos_bus_parent_parse_of(struct device_node *np,
        if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
                bus->ratio = DEFAULT_SATURATION_RATIO;
 
-       if (of_property_read_u32(np, "exynos,voltage-tolerance",
-                                       &bus->voltage_tolerance))
-               bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
-
        return 0;
 
 err_regulator:
-       regulator_disable(bus->regulator);
+       dev_pm_opp_put_regulators(bus->opp_table);
+       bus->opp_table = NULL;
 
        return ret;
 }
@@ -468,7 +384,7 @@ static int exynos_bus_probe(struct platform_device *pdev)
        goto out;
 passive:
        /* Initialize the struct profile and governor data for passive device */
-       profile->target = exynos_bus_passive_target;
+       profile->target = exynos_bus_target;
        profile->exit = exynos_bus_passive_exit;
 
        /* Get the instance of parent devfreq device */
@@ -508,8 +424,10 @@ static int exynos_bus_probe(struct platform_device *pdev)
        dev_pm_opp_of_remove_table(dev);
        clk_disable_unprepare(bus->clk);
 err_reg:
-       if (!passive)
-               regulator_disable(bus->regulator);
+       if (!passive) {
+               dev_pm_opp_put_regulators(bus->opp_table);
+               bus->opp_table = NULL;
+       }
 
        return ret;
 }