gpu: arm: midgard: add voltage scaling for devfreq

Support voltage scaling of mali regulator for devfreq.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>

diff --git a/drivers/gpu/arm/midgard/mali_kbase_devfreq.c b/drivers/gpu/arm/midgard/mali_kbase_devfreq.c
index 1191a7f..0f738c5 100644 (file)
--- a/drivers/gpu/arm/midgard/mali_kbase_devfreq.c
+++ b/drivers/gpu/arm/midgard/mali_kbase_devfreq.c
@@ -23,21 +23,80 @@
 #ifdef CONFIG_DEVFREQ_THERMAL
 #include <linux/devfreq_cooling.h>
 #endif
+#include <linux/regulator/consumer.h>
 
 #include "mali_kbase_power_actor.h"
 
+static int kbase_devfreq_target_up(struct kbase_device *kbdev,
+                                  unsigned long freq, unsigned long volt)
+{
+       unsigned int old_volt;
+       int err;
+
+       old_volt = regulator_get_voltage(kbdev->vdd);
+       if (old_volt < 0) {
+               dev_err(kbdev->dev, "failed to get voltage\n");
+               return old_volt;
+       }
+
+       err = regulator_set_voltage(kbdev->vdd, volt, volt);
+       if (err < 0) {
+               dev_err(kbdev->dev, "failed to set voltage\n");
+               return err;
+       }
+
+       err = clk_set_rate(kbdev->clock, freq);
+       if (err < 0) {
+               dev_err(kbdev->dev, "failed to set clock %lu\n", freq);
+               regulator_set_voltage(kbdev->vdd, old_volt, old_volt);
+               return err;
+       }
+
+       return 0;
+}
+
+static int kbase_devfreq_target_down(struct kbase_device *kbdev,
+                                    unsigned long freq, unsigned long volt)
+{
+       unsigned int old_freq;
+       int err;
+
+       old_freq = clk_get_rate(kbdev->clock);
+       if (old_freq < 0) {
+               dev_err(kbdev->dev, "failed to get clock rate\n");
+               return old_freq;
+       }
+
+       err = clk_set_rate(kbdev->clock, freq);
+       if (err < 0) {
+               dev_err(kbdev->dev, "failed to set clock %lu\n", freq);
+               return err;
+       }
+
+       err = regulator_set_voltage(kbdev->vdd, volt, volt);
+       if (err < 0) {
+               dev_err(kbdev->dev, "failed to set voltage\n");
+               clk_set_rate(kbdev->clock, old_freq);
+               return err;
+       }
+
+       return 0;
+}
+
 static int
 kbase_devfreq_target(struct device *dev, unsigned long *target_freq, u32 flags)
 {
        struct kbase_device *kbdev = dev_get_drvdata(dev);
        struct dev_pm_opp *opp;
        unsigned long freq = 0;
+       unsigned long volt;
        int err;
 
        freq = *target_freq;
 
        rcu_read_lock();
        opp = devfreq_recommended_opp(dev, &freq, flags);
+       volt = dev_pm_opp_get_voltage(opp);
        rcu_read_unlock();
        if (IS_ERR_OR_NULL(opp)) {
                dev_err(dev, "Failed to get opp (%ld)\n", PTR_ERR(opp));
@@ -52,12 +111,13 @@ kbase_devfreq_target(struct device *dev, unsigned long *target_freq, u32 flags)
                return 0;
        }
 
-       err = clk_set_rate(kbdev->clock, freq);
-       if (err) {
-               dev_err(dev, "Failed to set clock %lu (target %lu)\n",
-                               freq, *target_freq);
+       if (kbdev->freq < freq)
+               err = kbase_devfreq_target_up(kbdev, freq, volt);
+       else
+               err = kbase_devfreq_target_down(kbdev, freq, volt);
+
+       if (err < 0)
                return err;
-       }
 
        kbdev->freq = freq;
        *target_freq = freq;