Merge tag 'pull_req_20150331' of https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq into pm-devfreq

Pull devfreq updates for v4.1 from MyungJoo Ham.

"This set includes tegra driver update and style fixes."

* tag 'pull_req_20150331' of https://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
  PM / devfreq: tegra: Register governor on module init
  PM / devfreq: tegra: Enable interrupts after resuming the devfreq monitor
  PM / devfreq: tegra: Set drvdata before enabling the irq
  PM / devfreq: tegra: remove operating-points
  PM / devfreq: tegra: Use clock rate constraints
  PM / devfreq: tegra: Update to v5 of the submitted patches
  PM / devfreq: correct misleading comment
  PM / devfreq: event: Add const keyword for devfreq_event_ops structure

4 files changed, 290 insertions, 224 deletions

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 30b538d8cc90..ca1b362d77e2 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -392,7 +392,6 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
 /**
  * _remove_devfreq() - Remove devfreq from the list and release its resources.
  * @devfreq:    the devfreq struct
- * @skip:       skip calling device_unregister().
  */
 static void _remove_devfreq(struct devfreq *devfreq)
 {
diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c
index ad8347385f53..7d99d13bacd8 100644
--- a/drivers/devfreq/event/exynos-ppmu.c
+++ b/drivers/devfreq/event/exynos-ppmu.c
@@ -194,7 +194,7 @@ static int exynos_ppmu_get_event(struct devfreq_event_dev *edev,
         return 0;
 }
 
-static struct devfreq_event_ops exynos_ppmu_ops = {
+static const struct devfreq_event_ops exynos_ppmu_ops = {
         .disable = exynos_ppmu_disable,
         .set_event = exynos_ppmu_set_event,
         .get_event = exynos_ppmu_get_event,
diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index 34790961af5a..13a1a6e8108c 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -62,7 +62,8 @@
 #define ACTMON_BELOW_WMARK_WINDOW                               3
 #define ACTMON_BOOST_FREQ_STEP                                  16000
 
-/* activity counter is incremented every 256 memory transactions, and each
+/*
+ * Activity counter is incremented every 256 memory transactions, and each
  * transaction takes 4 EMC clocks for Tegra124; So the COUNT_WEIGHT is
  * 4 * 256 = 1024.
  */
@@ -85,16 +86,25 @@
  * struct tegra_devfreq_device_config - configuration specific to an ACTMON
  * device
  *
- * Coefficients and thresholds are in %
+ * Coefficients and thresholds are percentages unless otherwise noted
  */
 struct tegra_devfreq_device_config {
         u32             offset;
         u32             irq_mask;
 
+        /* Factors applied to boost_freq every consecutive watermark breach */
         unsigned int    boost_up_coeff;
         unsigned int    boost_down_coeff;
+
+        /* Define the watermark bounds when applied to the current avg */
         unsigned int    boost_up_threshold;
         unsigned int    boost_down_threshold;
+
+        /*
+         * Threshold of activity (cycles) below which the CPU frequency isn't
+         * to be taken into account. This is to avoid increasing the EMC
+         * frequency when the CPU is very busy but not accessing the bus often.
+         */
         u32             avg_dependency_threshold;
 };
 
@@ -105,7 +115,7 @@ enum tegra_actmon_device {
 
 static struct tegra_devfreq_device_config actmon_device_configs[] = {
         {
-                /* MCALL */
+                /* MCALL: All memory accesses (including from the CPUs) */
                 .offset = 0x1c0,
                 .irq_mask = 1 << 26,
                 .boost_up_coeff = 200,
@@ -114,7 +124,7 @@ static struct tegra_devfreq_device_config actmon_device_configs[] = {
                 .boost_down_threshold = 40,
         },
         {
-                /* MCCPU */
+                /* MCCPU: memory accesses from the CPUs */
                 .offset = 0x200,
                 .irq_mask = 1 << 25,
                 .boost_up_coeff = 800,
@@ -132,25 +142,29 @@ static struct tegra_devfreq_device_config actmon_device_configs[] = {
  */
 struct tegra_devfreq_device {
         const struct tegra_devfreq_device_config *config;
+        void __iomem *regs;
+        spinlock_t lock;
+
+        /* Average event count sampled in the last interrupt */
+        u32 avg_count;
 
-        void __iomem    *regs;
-        u32             avg_band_freq;
-        u32             avg_count;
+        /*
+         * Extra frequency to increase the target by due to consecutive
+         * watermark breaches.
+         */
+        unsigned long boost_freq;
 
-        unsigned long   target_freq;
-        unsigned long   boost_freq;
+        /* Optimal frequency calculated from the stats for this device */
+        unsigned long target_freq;
 };
 
 struct tegra_devfreq {
         struct devfreq          *devfreq;
 
-        struct platform_device  *pdev;
         struct reset_control    *reset;
         struct clk              *clock;
         void __iomem            *regs;
 
-        spinlock_t              lock;
-
         struct clk              *emc_clock;
         unsigned long           max_freq;
         unsigned long           cur_freq;
@@ -174,19 +188,43 @@ static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
         {  250000,    100000 },
 };
 
+static u32 actmon_readl(struct tegra_devfreq *tegra, u32 offset)
+{
+        return readl(tegra->regs + offset);
+}
+
+static void actmon_writel(struct tegra_devfreq *tegra, u32 val, u32 offset)
+{
+        writel(val, tegra->regs + offset);
+}
+
+static u32 device_readl(struct tegra_devfreq_device *dev, u32 offset)
+{
+        return readl(dev->regs + offset);
+}
+
+static void device_writel(struct tegra_devfreq_device *dev, u32 val,
+                          u32 offset)
+{
+        writel(val, dev->regs + offset);
+}
+
 static unsigned long do_percent(unsigned long val, unsigned int pct)
 {
         return val * pct / 100;
 }
 
-static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq_device *dev)
+static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra,
+                                           struct tegra_devfreq_device *dev)
 {
         u32 avg = dev->avg_count;
-        u32 band = dev->avg_band_freq * ACTMON_SAMPLING_PERIOD;
+        u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
+        u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD;
+
+        device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK);
 
-        writel(avg + band, dev->regs + ACTMON_DEV_AVG_UPPER_WMARK);
-        avg = max(avg, band);
-        writel(avg - band, dev->regs + ACTMON_DEV_AVG_LOWER_WMARK);
+        avg = max(dev->avg_count, band);
+        device_writel(dev, avg - band, ACTMON_DEV_AVG_LOWER_WMARK);
 }
 
 static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
@@ -194,96 +232,96 @@ static void tegra_devfreq_update_wmark(struct tegra