diff mbox

[v3,3/3] ARM: tegra: Add Tegra124 ACTMON support

Message ID 1417709696-29281-4-git-send-email-tomeu.vizoso@collabora.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tomeu Vizoso Dec. 4, 2014, 4:14 p.m. UTC
Add device node for the ACTMON block to the Tegra124 device tree.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

---

v3:	* Address misc. style issues found by Thierry and Alexander
	* Added helpers for register i/o
	* Further documented the structs
	* Enable the ACTMON after the IRQ handler has been installed
	* Disable the ACTMON before removing the IRQ handler
	* Add governor in a subsys initcall

v2:	* Add operating-points property
---
 arch/arm/boot/dts/tegra124.dtsi        |  23 +
 drivers/devfreq/Kconfig                |   7 +-
 drivers/devfreq/Makefile               |   2 +-
 drivers/devfreq/tegra-actmon-devfreq.c | 777 +++++++++++++++++++++++++++++++++
 drivers/devfreq/tegra-devfreq.c        | 718 ------------------------------
 5 files changed, 804 insertions(+), 723 deletions(-)
 create mode 100644 drivers/devfreq/tegra-actmon-devfreq.c
 delete mode 100644 drivers/devfreq/tegra-devfreq.c

Comments

Alexandre Courbot Dec. 9, 2014, 5:33 a.m. UTC | #1
On Fri, Dec 5, 2014 at 1:14 AM, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote:
> Add device node for the ACTMON block to the Tegra124 device tree.
>
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>
> ---
>
> v3:     * Address misc. style issues found by Thierry and Alexander
>         * Added helpers for register i/o
>         * Further documented the structs
>         * Enable the ACTMON after the IRQ handler has been installed
>         * Disable the ACTMON before removing the IRQ handler
>         * Add governor in a subsys initcall
>
> v2:     * Add operating-points property
> ---
>  arch/arm/boot/dts/tegra124.dtsi        |  23 +
>  drivers/devfreq/Kconfig                |   7 +-
>  drivers/devfreq/Makefile               |   2 +-
>  drivers/devfreq/tegra-actmon-devfreq.c | 777 +++++++++++++++++++++++++++++++++
>  drivers/devfreq/tegra-devfreq.c        | 718 ------------------------------

In patch 2/3 you create tegra-devfreq.c, to apparently move it to
tegra-actmon-devfreq.c and (seemingly) add somemore lines to it. This
makes things difficult to review, and I am almost sure this is a
naming mistake - could you fix this and resend?
Tomeu Vizoso Dec. 9, 2014, 2:13 p.m. UTC | #2
On 12/09/2014 06:33 AM, Alexandre Courbot wrote:
> On Fri, Dec 5, 2014 at 1:14 AM, Tomeu Vizoso <tomeu.vizoso@collabora.com> wrote:
>> Add device node for the ACTMON block to the Tegra124 device tree.
>>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>>
>> ---
>>
>> v3:     * Address misc. style issues found by Thierry and Alexander
>>         * Added helpers for register i/o
>>         * Further documented the structs
>>         * Enable the ACTMON after the IRQ handler has been installed
>>         * Disable the ACTMON before removing the IRQ handler
>>         * Add governor in a subsys initcall
>>
>> v2:     * Add operating-points property
>> ---
>>  arch/arm/boot/dts/tegra124.dtsi        |  23 +
>>  drivers/devfreq/Kconfig                |   7 +-
>>  drivers/devfreq/Makefile               |   2 +-
>>  drivers/devfreq/tegra-actmon-devfreq.c | 777 +++++++++++++++++++++++++++++++++
>>  drivers/devfreq/tegra-devfreq.c        | 718 ------------------------------
> 
> In patch 2/3 you create tegra-devfreq.c, to apparently move it to
> tegra-actmon-devfreq.c and (seemingly) add somemore lines to it. This
> makes things difficult to review, and I am almost sure this is a
> naming mistake - could you fix this and resend?

Sorry, I squashed the changes into the wrong commit. Have sent v4 fixing
this.

Cheers,

Tomeu
diff mbox

Patch

diff --git a/arch/arm/boot/dts/tegra124.dtsi b/arch/arm/boot/dts/tegra124.dtsi
index a49e7da..9d7baa8 100644
--- a/arch/arm/boot/dts/tegra124.dtsi
+++ b/arch/arm/boot/dts/tegra124.dtsi
@@ -215,6 +215,29 @@ 
 		reg = <0x0 0x60007000 0x0 0x1000>;
 	};
 
+	actmon@0,6000c800 {
+		compatible = "nvidia,tegra124-actmon";
+		reg = <0x0 0x6000c800 0x0 0x400>;
+		interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&tegra_car TEGRA124_CLK_ACTMON>,
+			 <&tegra_car TEGRA124_CLK_EMC>;
+		clock-names = "actmon", "emc";
+		resets = <&tegra_car 119>;
+		reset-names = "actmon";
+		operating-points = <
+			/* KHz	uV */
+			/* TODO: Add more points below 102 MHz */
+			102000	800000
+			204000	800000
+			300000	820000
+			396000	850000
+			528000	880000
+			600000	910000
+			792000	980000
+			924000	1010000
+		>;
+	};
+
 	gpio: gpio@0,6000d000 {
 		compatible = "nvidia,tegra124-gpio", "nvidia,tegra30-gpio";
 		reg = <0x0 0x6000d000 0x0 0x1000>;
diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig
index 4aab799..76be33a 100644
--- a/drivers/devfreq/Kconfig
+++ b/drivers/devfreq/Kconfig
@@ -87,10 +87,9 @@  config ARM_EXYNOS5_BUS_DEVFREQ
 	  It reads PPMU counters of memory controllers and adjusts the
 	  operating frequencies and voltages with OPP support.
 
-config ARM_TEGRA_DEVFREQ
-       tristate "Tegra DEVFREQ Driver"
-       depends on ARCH_TEGRA_124_SOC
-       select DEVFREQ_GOV_SIMPLE_ONDEMAND
+config ARM_TEGRA_ACTMON_DEVFREQ
+       bool "Tegra ACTMON DEVFREQ Driver"
+       depends on ARCH_TEGRA
        select PM_OPP
        help
          This adds the DEVFREQ driver for the Tegra family of SoCs.
diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile
index 0ea991f..c9159c5 100644
--- a/drivers/devfreq/Makefile
+++ b/drivers/devfreq/Makefile
@@ -7,4 +7,4 @@  obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
 # DEVFREQ Drivers
 obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
 obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/
-obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
+obj-$(CONFIG_ARM_TEGRA_ACTMON_DEVFREQ)	+= tegra-actmon-devfreq.o
diff --git a/drivers/devfreq/tegra-actmon-devfreq.c b/drivers/devfreq/tegra-actmon-devfreq.c
new file mode 100644
index 0000000..8d2ea22f
--- /dev/null
+++ b/drivers/devfreq/tegra-actmon-devfreq.c
@@ -0,0 +1,777 @@ 
+/*
+ * A devfreq driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved.
+ * Copyright (C) 2014 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/devfreq.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/reset.h>
+
+#include "governor.h"
+
+#define ACTMON_GLB_STATUS					0x0
+#define ACTMON_GLB_PERIOD_CTRL					0x4
+
+#define ACTMON_DEV_CTRL						0x0
+#define ACTMON_DEV_CTRL_K_VAL_SHIFT				10
+#define ACTMON_DEV_CTRL_ENB_PERIODIC				BIT(18)
+#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN			BIT(20)
+#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN			BIT(21)
+#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT	23
+#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT	26
+#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN		BIT(29)
+#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN		BIT(30)
+#define ACTMON_DEV_CTRL_ENB					BIT(31)
+
+#define ACTMON_DEV_UPPER_WMARK					0x4
+#define ACTMON_DEV_LOWER_WMARK					0x8
+#define ACTMON_DEV_INIT_AVG					0xc
+#define ACTMON_DEV_AVG_UPPER_WMARK				0x10
+#define ACTMON_DEV_AVG_LOWER_WMARK				0x14
+#define ACTMON_DEV_COUNT_WEIGHT					0x18
+#define ACTMON_DEV_AVG_COUNT					0x20
+#define ACTMON_DEV_INTR_STATUS					0x24
+
+#define ACTMON_INTR_STATUS_CLEAR				0xffffffff
+
+#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER			BIT(31)
+#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER			BIT(30)
+
+#define ACTMON_ABOVE_WMARK_WINDOW				1
+#define ACTMON_BELOW_WMARK_WINDOW				3
+#define ACTMON_BOOST_FREQ_STEP					16000
+
+/*
+ * 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.
+ */
+#define ACTMON_COUNT_WEIGHT					0x400
+
+/*
+ * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which
+ * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
+ */
+#define ACTMON_AVERAGE_WINDOW_LOG2			6
+#define ACTMON_SAMPLING_PERIOD				12 /* ms */
+#define ACTMON_DEFAULT_AVG_BAND				6  /* 1/10 of % */
+
+#define KHZ							1000
+
+/* Assume that the bus is saturated if the utilization is 25% */
+#define BUS_SATURATION_RATIO					25
+
+/**
+ * struct tegra_devfreq_device_config - configuration specific to an ACTMON
+ * device
+ *
+ * Coefficients and thresholds are in %
+ */
+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 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;
+};
+
+enum tegra_actmon_device {
+	MCALL = 0,
+	MCCPU,
+};
+
+static struct tegra_devfreq_device_config actmon_device_configs[] = {
+	{
+		/* MCALL: All memory accesses (including from the CPUs) */
+		.offset = 0x1c0,
+		.irq_mask = 1 << 26,
+		.boost_up_coeff = 200,
+		.boost_down_coeff = 50,
+		.boost_up_threshold = 60,
+		.boost_down_threshold = 40,
+	},
+	{
+		/* MCCPU: memory accesses from the CPUs */
+		.offset = 0x200,
+		.irq_mask = 1 << 25,
+		.boost_up_coeff = 800,
+		.boost_down_coeff = 90,
+		.boost_up_threshold = 27,
+		.boost_down_threshold = 10,
+		.avg_dependency_threshold = 50000,
+	},
+};
+
+/**
+ * struct tegra_devfreq_device - state specific to an ACTMON device
+ *
+ * Frequencies are in kHz.
+ */
+struct tegra_devfreq_device {
+	const struct tegra_devfreq_device_config *config;
+
+	void __iomem *regs;
+
+	/* Average event count sampled in the last interrupt */
+	u32 avg_count;
+
+	/*
+	 * Extra frequency to increase the target by due to consecutive
+	 * watermark breaches.
+	 */
+	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;
+	struct notifier_block	rate_change_nb;
+
+	struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
+};
+
+struct tegra_actmon_emc_ratio {
+	unsigned long cpu_freq;
+	unsigned long emc_freq;
+};
+
+static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
+	{ 1400000, ULONG_MAX },
+	{ 1200000,    750000 },
+	{ 1100000,    600000 },
+	{ 1000000,    500000 },
+	{  800000,    375000 },
+	{  500000,    200000 },
+	{  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 *tegra,
+					   struct tegra_devfreq_device *dev)
+{
+	u32 avg = dev->avg_count;
+	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);
+
+	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,
+				       struct tegra_devfreq_device *dev)
+{
+	u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
+
+	device_writel(dev, do_percent(val, dev->config->boost_up_threshold),
+		      ACTMON_DEV_UPPER_WMARK);
+
+	device_writel(dev, do_percent(val, dev->config->boost_down_threshold),
+		      ACTMON_DEV_LOWER_WMARK);
+}
+
+static void actmon_write_barrier(struct tegra_devfreq *tegra)
+{
+	/* ensure the update has reached the ACTMON */
+	wmb();
+	actmon_readl(tegra, ACTMON_GLB_STATUS);
+}
+
+static irqreturn_t actmon_isr(int irq, void *data)
+{
+	struct tegra_devfreq *tegra = data;
+	struct tegra_devfreq_device *dev = NULL;
+	unsigned long flags;
+	u32 val, intr_status, dev_ctrl;
+	unsigned int i;
+
+	val = actmon_readl(tegra, ACTMON_GLB_STATUS);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		if (val & tegra->devices[i].config->irq_mask) {
+			dev = tegra->devices + i;
+			break;
+		}
+	}
+
+	if (!dev)
+		return IRQ_NONE;
+
+	spin_lock_irqsave(&tegra->lock, flags);
+
+	dev->avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT);
+	tegra_devfreq_update_avg_wmark(tegra, dev);
+
+	intr_status = device_readl(dev, ACTMON_DEV_INTR_STATUS);
+	dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL);
+
+	if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {
+		/*
+		 * new_boost = min(old_boost * up_coef + step, max_freq)
+		 */
+		dev->boost_freq = do_percent(dev->boost_freq,
+					     dev->config->boost_up_coeff);
+		dev->boost_freq += ACTMON_BOOST_FREQ_STEP;
+
+		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+
+		if (dev->boost_freq >= tegra->max_freq)
+			dev->boost_freq = tegra->max_freq;
+		else
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+	} else if (intr_status & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
+		/*
+		 * new_boost = old_boost * down_coef
+		 * or 0 if (old_boost * down_coef < step / 2)
+		 */
+		dev->boost_freq = do_percent(dev->boost_freq,
+					     dev->config->boost_down_coeff);
+
+		dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1))
+			dev->boost_freq = 0;
+		else
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+	}
+
+	if (dev->config->avg_dependency_threshold) {
+		if (dev->avg_count >= dev->config->avg_dependency_threshold)
+			dev_ctrl |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+		else if (dev->boost_freq == 0)
+			dev_ctrl &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
+	}
+
+	device_writel(dev, dev_ctrl, ACTMON_DEV_CTRL);
+
+	device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
+
+	actmon_write_barrier(tegra);
+
+	spin_unlock_irqrestore(&tegra->lock, flags);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
+					    unsigned long cpu_freq)
+{
+	unsigned int i;
+	struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
+
+	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
+		if (cpu_freq >= ratio->cpu_freq) {
+			if (ratio->emc_freq >= tegra->max_freq)
+				return tegra->max_freq;
+			else
+				return ratio->emc_freq;
+		}
+	}
+
+	return 0;
+}
+
+static void actmon_update_target(struct tegra_devfreq *tegra,
+				 struct tegra_devfreq_device *dev)
+{
+	unsigned long cpu_freq = 0;
+	unsigned long static_cpu_emc_freq = 0;
+	unsigned int avg_sustain_coef;
+	unsigned long flags;
+
+	if (dev->config->avg_dependency_threshold) {
+		cpu_freq = cpufreq_get(0);
+		static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
+	}
+
+	spin_lock_irqsave(&tegra->lock, flags);
+
+	dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
+	avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
+	dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);
+	dev->target_freq += dev->boost_freq;
+
+	if (dev->avg_count >= dev->config->avg_dependency_threshold)
+		dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
+
+	spin_unlock_irqrestore(&tegra->lock, flags);
+}
+
+static irqreturn_t actmon_thread_isr(int irq, void *data)
+{
+	struct tegra_devfreq *tegra = data;
+
+	mutex_lock(&tegra->devfreq->lock);
+	update_devfreq(tegra->devfreq);
+	mutex_unlock(&tegra->devfreq->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
+				       unsigned long action, void *ptr)
+{
+	struct clk_notifier_data *data = ptr;
+	struct tegra_devfreq *tegra;
+	unsigned int i;
+	unsigned long flags;
+
+	if (action != POST_RATE_CHANGE)
+		return NOTIFY_OK;
+
+	tegra = container_of(nb, struct tegra_devfreq, rate_change_nb);
+
+	spin_lock_irqsave(&tegra->lock, flags);
+
+	tegra->cur_freq = data->new_rate / KHZ;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)
+		tegra_devfreq_update_wmark(tegra, tegra->devices + i);
+
+	actmon_write_barrier(tegra);
+
+	spin_unlock_irqrestore(&tegra->lock, flags);
+
+	return NOTIFY_OK;
+}
+
+static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
+					  struct tegra_devfreq_device *dev)
+{
+	u32 val = 0;
+
+	dev->target_freq = tegra->cur_freq;
+
+	dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
+	device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG);
+
+	tegra_devfreq_update_avg_wmark(tegra, dev);
+	tegra_devfreq_update_wmark(tegra, dev);
+
+	device_writel(dev, ACTMON_COUNT_WEIGHT, ACTMON_DEV_COUNT_WEIGHT);
+	device_writel(dev, ACTMON_INTR_STATUS_CLEAR, ACTMON_DEV_INTR_STATUS);
+
+	val |= ACTMON_DEV_CTRL_ENB_PERIODIC |
+	       ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN |
+	       ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
+	val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)
+		<< ACTMON_DEV_CTRL_K_VAL_SHIFT;
+	val |= (ACTMON_BELOW_WMARK_WINDOW - 1)
+		<< ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;
+	val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)
+		<< ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;
+	val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN |
+	       ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
+
+	device_writel(dev, val, ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+}
+
+static void tegra_actmon_enable_device(struct tegra_devfreq *tegra,
+				       struct tegra_devfreq_device *dev)
+{
+	u32 val;
+
+	val = device_readl(dev, ACTMON_DEV_CTRL);
+	val |= ACTMON_DEV_CTRL_ENB;
+	device_writel(dev, val, ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+}
+
+static void tegra_actmon_disable_device(struct tegra_devfreq *tegra,
+					struct tegra_devfreq_device *dev)
+{
+	u32 val;
+
+	val = device_readl(dev, ACTMON_DEV_CTRL);
+	val &= ~ACTMON_DEV_CTRL_ENB;
+	device_writel(dev, val, ACTMON_DEV_CTRL);
+
+	actmon_write_barrier(tegra);
+}
+
+static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
+				u32 flags)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct dev_pm_opp *opp;
+	unsigned long rate = *freq * KHZ;
+
+	pdev = container_of(dev, struct platform_device, dev);
+
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(dev, &rate, flags);
+	if (IS_ERR(opp)) {
+		rcu_read_unlock();
+		dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);
+		return PTR_ERR(opp);
+	}
+	rate = dev_pm_opp_get_freq(opp);
+	rcu_read_unlock();
+
+	/* TODO: Once we have per-user clk constraints, set a floor */
+	clk_set_rate(tegra->emc_clock, rate);
+
+	/* TODO: Set voltage as well */
+
+	return 0;
+}
+
+static int tegra_devfreq_get_dev_status(struct device *dev,
+					struct devfreq_dev_status *stat)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct tegra_devfreq_device *actmon_dev;
+
+	pdev = container_of(dev, struct platform_device, dev);
+
+	stat->current_frequency = tegra->cur_freq;
+
+	/* To be used by the tegra governor */
+	stat->private_data = tegra;
+
+	/* The below are to be used by the other governors */
+
+	actmon_dev = &tegra->devices[MCALL];
+
+	/* Number of cycles spent on memory access */
+	stat->busy_time = actmon_dev->avg_count;
+
+	/* The bus can be considered to be saturated way before 100% */
+	stat->busy_time *= 100 / BUS_SATURATION_RATIO;
+
+	/* Number of cycles in a sampling period */
+	stat->total_time = ACTMON_SAMPLING_PERIOD * tegra->cur_freq;
+
+	return 0;
+}
+
+static struct devfreq_dev_profile tegra_devfreq_profile = {
+	.polling_ms	= 0,
+	.target		= tegra_devfreq_target,
+	.get_dev_status	= tegra_devfreq_get_dev_status,
+};
+
+static int tegra_governor_get_target(struct devfreq *devfreq,
+				     unsigned long *freq)
+{
+	struct devfreq_dev_status stat;
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	unsigned long target_freq = 0;
+	unsigned int i;
+	int err;
+
+	err = devfreq->profile->get_dev_status(devfreq->dev.parent, &stat);
+	if (err)
+		return err;
+
+	tegra = stat.private_data;
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		dev = &tegra->devices[i];
+
+		actmon_update_target(tegra, dev);
+
+		target_freq = max(target_freq, dev->target_freq);
+	}
+
+	*freq = target_freq;
+
+	return 0;
+}
+
+static int tegra_governor_event_handler(struct devfreq *devfreq,
+					unsigned int event, void *data)
+{
+	return 0;
+}
+
+static struct devfreq_governor tegra_devfreq_governor = {
+	.name = "tegra_actmon",
+	.get_target_freq = tegra_governor_get_target,
+	.event_handler = tegra_governor_event_handler,
+};
+
+static int __init tegra_governor_init(void)
+{
+	return devfreq_add_governor(&tegra_devfreq_governor);
+}
+subsys_initcall(tegra_governor_init);
+
+static int tegra_devfreq_probe(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra;
+	struct tegra_devfreq_device *dev;
+	struct resource *res;
+	unsigned long max_freq;
+	unsigned int i;
+	int irq;
+	int err;
+
+	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
+	if (!tegra)
+		return -ENOMEM;
+
+	spin_lock_init(&tegra->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tegra->regs))
+		return PTR_ERR(tegra->regs);
+
+	tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
+	if (IS_ERR(tegra->reset)) {
+		dev_err(&pdev->dev, "Failed to get reset\n");
+		return PTR_ERR(tegra->reset);
+	}
+
+	tegra->clock = devm_clk_get(&pdev->dev, "actmon");
+	if (IS_ERR(tegra->clock)) {
+		dev_err(&pdev->dev, "Failed to get actmon clock\n");
+		return PTR_ERR(tegra->clock);
+	}
+
+	tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
+	if (IS_ERR(tegra->emc_clock)) {
+		dev_err(&pdev->dev, "Failed to get emc clock\n");
+		return PTR_ERR(tegra->emc_clock);
+	}
+
+	err = of_init_opp_table(&pdev->dev);
+	if (err) {
+		dev_err(&pdev->dev, "Failed to init operating point table\n");
+		return err;
+	}
+
+	tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb;
+	err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
+	if (err) {
+		dev_err(&pdev->dev,
+			"Failed to register rate change notifier\n");
+		return err;
+	}
+
+	reset_control_assert(tegra->reset);
+
+	err = clk_prepare_enable(tegra->clock);
+	if (err) {
+		dev_err(&pdev->dev,
+			"Failed to prepare and enable ACTMON clock\n");
+		return err;
+	}
+
+	reset_control_deassert(tegra->reset);
+
+	max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX);
+	tegra->max_freq = max_freq / KHZ;
+
+	clk_set_rate(tegra->emc_clock, max_freq);
+
+	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
+
+	actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1,
+		      ACTMON_GLB_PERIOD_CTRL);
+
+	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
+		dev = tegra->devices + i;
+		dev->config = actmon_device_configs + i;
+		dev->regs = tegra->regs + dev->config->offset;
+
+		tegra_actmon_configure_device(tegra, dev);
+	}
+
+	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
+	tegra->devfreq = devm_devfreq_add_device(&pdev->dev,
+						 &tegra_devfreq_profile,
+						 "tegra_actmon",
+						 NULL);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0) {
+		dev_err(&pdev->dev, "Failed to get IRQ\n");
+		return -ENODEV;
+	}
+
+	platform_set_drvdata(pdev, tegra);
+
+	err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr,
+					actmon_thread_isr, IRQF_SHARED,
+					"tegra-devfreq", tegra);
+	if (err) {
+		dev_err(&pdev->dev, "Interrupt request failed\n");
+		return err;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++)
+		tegra_actmon_enable_device(tegra, tegra->devices + i);
+
+	return 0;
+}
+
+static int tegra_devfreq_remove(struct platform_device *pdev)
+{
+	struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
+	int irq = platform_get_irq(pdev, 0);
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++)
+		tegra_actmon_disable_device(tegra, tegra->devices + i);
+
+	devm_free_irq(&pdev->dev, irq, tegra);
+
+	clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
+
+	clk_disable_unprepare(tegra->clock);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int tegra_devfreq_suspend(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct tegra_devfreq_device *actmon_dev;
+	unsigned int i;
+
+	pdev = container_of(dev, struct platform_device, dev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		actmon_dev = &tegra->devices[i];
+
+		tegra_actmon_disable_device(tegra, actmon_dev);
+
+		device_writel(actmon_dev, ACTMON_INTR_STATUS_CLEAR,
+			      ACTMON_DEV_INTR_STATUS);
+
+		actmon_write_barrier(tegra);
+	}
+
+	return 0;
+}
+
+static int tegra_devfreq_resume(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
+	struct tegra_devfreq_device *actmon_dev;
+	unsigned int i;
+
+	pdev = container_of(dev, struct platform_device, dev);
+
+	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
+		actmon_dev = &tegra->devices[i];
+
+		tegra_actmon_configure_device(tegra, actmon_dev);
+		tegra_actmon_enable_device(tegra, actmon_dev);
+	}
+
+	return 0;
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(tegra_devfreq_pm_ops,
+			 tegra_devfreq_suspend,
+			 tegra_devfreq_resume);
+
+static struct of_device_id tegra_devfreq_of_match[] = {
+	{ .compatible = "nvidia,tegra124-actmon" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);
+
+static struct platform_driver tegra_devfreq_driver = {
+	.probe	= tegra_devfreq_probe,
+	.remove	= tegra_devfreq_remove,
+	.driver = {
+		.name = "tegra-devfreq",
+		.of_match_table = tegra_devfreq_of_match,
+		.pm = &tegra_devfreq_pm_ops,
+	},
+};
+module_platform_driver(tegra_devfreq_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Tegra devfreq driver");
+MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");
diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
deleted file mode 100644
index 3479096..0000000
--- a/drivers/devfreq/tegra-devfreq.c
+++ /dev/null
@@ -1,718 +0,0 @@ 
-/*
- * A devfreq driver for NVIDIA Tegra SoCs
- *
- * Copyright (c) 2014 NVIDIA CORPORATION. All rights reserved.
- * Copyright (C) 2014 Google, Inc
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
- * more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-#include <linux/clk.h>
-#include <linux/cpufreq.h>
-#include <linux/devfreq.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/pm_opp.h>
-#include <linux/reset.h>
-
-#include "governor.h"
-
-#define ACTMON_GLB_STATUS					0x0
-#define ACTMON_GLB_PERIOD_CTRL					0x4
-
-#define ACTMON_DEV_CTRL						0x0
-#define ACTMON_DEV_CTRL_K_VAL_SHIFT				10
-#define ACTMON_DEV_CTRL_ENB_PERIODIC				BIT(18)
-#define ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN			BIT(20)
-#define ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN			BIT(21)
-#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT	23
-#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT	26
-#define ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN		BIT(29)
-#define ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN		BIT(30)
-#define ACTMON_DEV_CTRL_ENB					BIT(31)
-
-#define ACTMON_DEV_UPPER_WMARK					0x4
-#define ACTMON_DEV_LOWER_WMARK					0x8
-#define ACTMON_DEV_INIT_AVG					0xc
-#define ACTMON_DEV_AVG_UPPER_WMARK				0x10
-#define ACTMON_DEV_AVG_LOWER_WMARK				0x14
-#define ACTMON_DEV_COUNT_WEIGHT					0x18
-#define ACTMON_DEV_AVG_COUNT					0x20
-#define ACTMON_DEV_INTR_STATUS					0x24
-
-#define ACTMON_INTR_STATUS_CLEAR				0xffffffff
-
-#define ACTMON_DEV_INTR_CONSECUTIVE_UPPER			BIT(31)
-#define ACTMON_DEV_INTR_CONSECUTIVE_LOWER			BIT(30)
-
-#define ACTMON_ABOVE_WMARK_WINDOW				1
-#define ACTMON_BELOW_WMARK_WINDOW				3
-#define ACTMON_BOOST_FREQ_STEP					16000
-
-/* 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.
- */
-#define ACTMON_COUNT_WEIGHT					0x400
-
-/*
- * ACTMON_AVERAGE_WINDOW_LOG2: default value for @DEV_CTRL_K_VAL, which
- * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
- */
-#define ACTMON_AVERAGE_WINDOW_LOG2			6
-#define ACTMON_SAMPLING_PERIOD				12 /* ms */
-#define ACTMON_DEFAULT_AVG_BAND				6  /* 1/10 of % */
-
-#define KHZ							1000
-
-/* Assume that the bus is saturated if the utilization is 25% */
-#define BUS_SATURATION_RATIO					25
-
-/**
- * struct tegra_devfreq_device_config - configuration specific to an ACTMON
- * device
- *
- * Coefficients and thresholds are in %
- */
-struct tegra_devfreq_device_config {
-	u32		offset;
-	u32		irq_mask;
-
-	unsigned int	boost_up_coeff;
-	unsigned int	boost_down_coeff;
-	unsigned int	boost_up_threshold;
-	unsigned int	boost_down_threshold;
-	u32		avg_dependency_threshold;
-};
-
-enum tegra_actmon_device {
-	MCALL = 0,
-	MCCPU,
-};
-
-static struct tegra_devfreq_device_config actmon_device_configs[] = {
-	{
-		/* MCALL */
-		.offset = 0x1c0,
-		.irq_mask = 1 << 26,
-		.boost_up_coeff = 200,
-		.boost_down_coeff = 50,
-		.boost_up_threshold = 60,
-		.boost_down_threshold = 40,
-	},
-	{
-		/* MCCPU */
-		.offset = 0x200,
-		.irq_mask = 1 << 25,
-		.boost_up_coeff = 800,
-		.boost_down_coeff = 90,
-		.boost_up_threshold = 27,
-		.boost_down_threshold = 10,
-		.avg_dependency_threshold = 50000,
-	},
-};
-
-/**
- * struct tegra_devfreq_device - state specific to an ACTMON device
- *
- * Frequencies are in kHz.
- */
-struct tegra_devfreq_device {
-	const struct tegra_devfreq_device_config *config;
-
-	void __iomem	*regs;
-	u32		avg_band_freq;
-	u32		avg_count;
-
-	unsigned long	target_freq;
-	unsigned long	boost_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;
-	struct notifier_block	rate_change_nb;
-
-	struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)];
-};
-
-struct tegra_actmon_emc_ratio {
-	unsigned long cpu_freq;
-	unsigned long emc_freq;
-};
-
-static struct tegra_actmon_emc_ratio actmon_emc_ratios[] = {
-	{ 1400000, ULONG_MAX },
-	{ 1200000,    750000 },
-	{ 1100000,    600000 },
-	{ 1000000,    500000 },
-	{  800000,    375000 },
-	{  500000,    200000 },
-	{  250000,    100000 },
-};
-
-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)
-{
-	u32 avg = dev->avg_count;
-	u32 band = dev->avg_band_freq * ACTMON_SAMPLING_PERIOD;
-
-	writel(avg + band, dev->regs + ACTMON_DEV_AVG_UPPER_WMARK);
-	avg = max(avg, band);
-	writel(avg - band, dev->regs + ACTMON_DEV_AVG_LOWER_WMARK);
-}
-
-static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
-				       struct tegra_devfreq_device *dev)
-{
-	u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
-
-	writel(do_percent(val, dev->config->boost_up_threshold),
-	       dev->regs + ACTMON_DEV_UPPER_WMARK);
-
-	writel(do_percent(val, dev->config->boost_down_threshold),
-	       dev->regs + ACTMON_DEV_LOWER_WMARK);
-}
-
-static void actmon_write_barrier(struct tegra_devfreq *tegra)
-{
-	/* ensure the update has reached the ACTMON */
-	wmb();
-	readl(tegra->regs + ACTMON_GLB_STATUS);
-}
-
-static irqreturn_t actmon_isr(int irq, void *data)
-{
-	struct tegra_devfreq *tegra = data;
-	struct tegra_devfreq_device *dev = NULL;
-	unsigned long flags;
-	u32 val;
-	unsigned int i;
-
-	val = readl(tegra->regs + ACTMON_GLB_STATUS);
-
-	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
-		if (val & tegra->devices[i].config->irq_mask) {
-			dev = tegra->devices + i;
-			break;
-		}
-	}
-
-	if (!dev)
-		return IRQ_NONE;
-
-	spin_lock_irqsave(&tegra->lock, flags);
-
-	dev->avg_count = readl(dev->regs + ACTMON_DEV_AVG_COUNT);
-	tegra_devfreq_update_avg_wmark(dev);
-
-	val = readl(dev->regs + ACTMON_DEV_INTR_STATUS);
-	if (val & ACTMON_DEV_INTR_CONSECUTIVE_UPPER) {
-		val = readl(dev->regs + ACTMON_DEV_CTRL) |
-			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |
-			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
-
-		/*
-		 * new_boost = min(old_boost * up_coef + step, max_freq)
-		 */
-		dev->boost_freq = do_percent(dev->boost_freq,
-					     dev->config->boost_up_coeff);
-		dev->boost_freq += ACTMON_BOOST_FREQ_STEP;
-		if (dev->boost_freq >= tegra->max_freq) {
-			dev->boost_freq = tegra->max_freq;
-			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
-		}
-		writel(val, dev->regs + ACTMON_DEV_CTRL);
-	} else if (val & ACTMON_DEV_INTR_CONSECUTIVE_LOWER) {
-		val = readl(dev->regs + ACTMON_DEV_CTRL) |
-			ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN |
-			ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
-
-		/*
-		 * new_boost = old_boost * down_coef
-		 * or 0 if (old_boost * down_coef < step / 2)
-		 */
-		dev->boost_freq = do_percent(dev->boost_freq,
-					     dev->config->boost_down_coeff);
-		if (dev->boost_freq < (ACTMON_BOOST_FREQ_STEP >> 1)) {
-			dev->boost_freq = 0;
-			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
-		}
-		writel(val, dev->regs + ACTMON_DEV_CTRL);
-	}
-
-	if (dev->config->avg_dependency_threshold) {
-		val = readl(dev->regs + ACTMON_DEV_CTRL);
-		if (dev->avg_count >= dev->config->avg_dependency_threshold)
-			val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
-		else if (dev->boost_freq == 0)
-			val &= ~ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN;
-		writel(val, dev->regs + ACTMON_DEV_CTRL);
-	}
-
-	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS);
-
-	actmon_write_barrier(tegra);
-
-	spin_unlock_irqrestore(&tegra->lock, flags);
-
-	return IRQ_WAKE_THREAD;
-}
-
-static unsigned long actmon_cpu_to_emc_rate(struct tegra_devfreq *tegra,
-					    unsigned long cpu_freq)
-{
-	unsigned int i;
-	struct tegra_actmon_emc_ratio *ratio = actmon_emc_ratios;
-
-	for (i = 0; i < ARRAY_SIZE(actmon_emc_ratios); i++, ratio++) {
-		if (cpu_freq >= ratio->cpu_freq) {
-			if (ratio->emc_freq >= tegra->max_freq)
-				return tegra->max_freq;
-			else
-				return ratio->emc_freq;
-		}
-	}
-
-	return 0;
-}
-
-static void actmon_update_target(struct tegra_devfreq *tegra,
-				 struct tegra_devfreq_device *dev)
-{
-	unsigned long cpu_freq = 0;
-	unsigned long static_cpu_emc_freq = 0;
-	unsigned int avg_sustain_coef;
-	unsigned long flags;
-
-	if (dev->config->avg_dependency_threshold) {
-		cpu_freq = cpufreq_get(0);
-		static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
-	}
-
-	spin_lock_irqsave(&tegra->lock, flags);
-
-	dev->target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
-	avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
-	dev->target_freq = do_percent(dev->target_freq, avg_sustain_coef);
-	dev->target_freq += dev->boost_freq;
-
-	if (dev->avg_count >= dev->config->avg_dependency_threshold)
-		dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
-
-	spin_unlock_irqrestore(&tegra->lock, flags);
-}
-
-static irqreturn_t actmon_thread_isr(int irq, void *data)
-{
-	struct tegra_devfreq *tegra = data;
-
-	mutex_lock(&tegra->devfreq->lock);
-	update_devfreq(tegra->devfreq);
-	mutex_unlock(&tegra->devfreq->lock);
-
-	return IRQ_HANDLED;
-}
-
-static int tegra_actmon_rate_notify_cb(struct notifier_block *nb,
-				       unsigned long action, void *ptr)
-{
-	struct clk_notifier_data *data = ptr;
-	struct tegra_devfreq *tegra = container_of(nb, struct tegra_devfreq,
-						   rate_change_nb);
-	unsigned int i;
-	unsigned long flags;
-
-	spin_lock_irqsave(&tegra->lock, flags);
-
-	switch (action) {
-	case POST_RATE_CHANGE:
-		tegra->cur_freq = data->new_rate / KHZ;
-
-		for (i = 0; i < ARRAY_SIZE(tegra->devices); i++)
-			tegra_devfreq_update_wmark(tegra, tegra->devices + i);
-
-		actmon_write_barrier(tegra);
-		break;
-	case PRE_RATE_CHANGE:
-		/* fall through */
-	case ABORT_RATE_CHANGE:
-		break;
-	};
-
-	spin_unlock_irqrestore(&tegra->lock, flags);
-
-	return NOTIFY_OK;
-}
-
-static void tegra_actmon_configure_device(struct tegra_devfreq *tegra,
-					  struct tegra_devfreq_device *dev)
-{
-	u32 val;
-
-	dev->avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ;
-	dev->target_freq = tegra->cur_freq;
-
-	dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD;
-	writel(dev->avg_count, dev->regs + ACTMON_DEV_INIT_AVG);
-
-	tegra_devfreq_update_avg_wmark(dev);
-	tegra_devfreq_update_wmark(tegra, dev);
-
-	writel(ACTMON_COUNT_WEIGHT, dev->regs + ACTMON_DEV_COUNT_WEIGHT);
-	writel(ACTMON_INTR_STATUS_CLEAR, dev->regs + ACTMON_DEV_INTR_STATUS);
-
-	val = 0;
-	val |= ACTMON_DEV_CTRL_ENB_PERIODIC |
-	       ACTMON_DEV_CTRL_AVG_ABOVE_WMARK_EN |
-	       ACTMON_DEV_CTRL_AVG_BELOW_WMARK_EN;
-	val |= (ACTMON_AVERAGE_WINDOW_LOG2 - 1)
-		<< ACTMON_DEV_CTRL_K_VAL_SHIFT;
-	val |= (ACTMON_BELOW_WMARK_WINDOW - 1)
-		<< ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_NUM_SHIFT;
-	val |= (ACTMON_ABOVE_WMARK_WINDOW - 1)
-		<< ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_NUM_SHIFT;
-	val |= ACTMON_DEV_CTRL_CONSECUTIVE_BELOW_WMARK_EN |
-	       ACTMON_DEV_CTRL_CONSECUTIVE_ABOVE_WMARK_EN;
-
-	writel(val, dev->regs + ACTMON_DEV_CTRL);
-
-	actmon_write_barrier(tegra);
-
-	val = readl(dev->regs + ACTMON_DEV_CTRL);
-	val |= ACTMON_DEV_CTRL_ENB;
-	writel(val, dev->regs + ACTMON_DEV_CTRL);
-
-	actmon_write_barrier(tegra);
-}
-
-static int tegra_devfreq_suspend(struct device *dev)
-{
-	struct platform_device *pdev;
-	struct tegra_devfreq *tegra;
-	struct tegra_devfreq_device *actmon_dev;
-	unsigned int i;
-	u32 val;
-
-	pdev = container_of(dev, struct platform_device, dev);
-	tegra = platform_get_drvdata(pdev);
-
-	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
-		actmon_dev = &tegra->devices[i];
-
-		val = readl(actmon_dev->regs + ACTMON_DEV_CTRL);
-		val &= ~ACTMON_DEV_CTRL_ENB;
-		writel(val, actmon_dev->regs + ACTMON_DEV_CTRL);
-
-		writel(ACTMON_INTR_STATUS_CLEAR,
-		       actmon_dev->regs + ACTMON_DEV_INTR_STATUS);
-
-		actmon_write_barrier(tegra);
-	}
-
-	return 0;
-}
-
-static int tegra_devfreq_resume(struct device *dev)
-{
-	struct platform_device *pdev;
-	struct tegra_devfreq *tegra;
-	struct tegra_devfreq_device *actmon_dev;
-	unsigned int i;
-
-	pdev = container_of(dev, struct platform_device, dev);
-	tegra = platform_get_drvdata(pdev);
-
-	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
-		actmon_dev = &tegra->devices[i];
-
-		tegra_actmon_configure_device(tegra, actmon_dev);
-	}
-
-	return 0;
-}
-
-static int tegra_devfreq_target(struct device *dev, unsigned long *freq,
-				u32 flags)
-{
-	struct platform_device *pdev;
-	struct tegra_devfreq *tegra;
-	struct dev_pm_opp *opp;
-	unsigned long rate = *freq * KHZ;
-
-	pdev = container_of(dev, struct platform_device, dev);
-	tegra = platform_get_drvdata(pdev);
-
-	rcu_read_lock();
-	opp = devfreq_recommended_opp(dev, &rate, flags);
-	if (IS_ERR(opp)) {
-		rcu_read_unlock();
-		dev_err(dev, "Failed to find opp for %lu KHz\n", *freq);
-		return PTR_ERR(opp);
-	}
-	rate = dev_pm_opp_get_freq(opp);
-	rcu_read_unlock();
-
-	/* TODO: Once we have per-user clk constraints, set a floor */
-	clk_set_rate(tegra->emc_clock, rate);
-
-	/* TODO: Set voltage as well */
-
-	return 0;
-}
-
-static int tegra_devfreq_get_dev_status(struct device *dev,
-					struct devfreq_dev_status *stat)
-{
-	struct platform_device *pdev;
-	struct tegra_devfreq *tegra;
-	struct tegra_devfreq_device *actmon_dev;
-
-	pdev = container_of(dev, struct platform_device, dev);
-	tegra = platform_get_drvdata(pdev);
-
-	stat->current_frequency = tegra->cur_freq;
-
-	/* To be used by the tegra governor */
-	stat->private_data = tegra;
-
-	/* The below are to be used by the other governors */
-
-	actmon_dev = &tegra->devices[MCALL];
-
-	/* Number of cycles spent on memory access */
-	stat->busy_time = actmon_dev->avg_count;
-
-	/* The bus can be considered to be saturated way before 100% */
-	stat->busy_time *= 100 / BUS_SATURATION_RATIO;
-
-	/* Number of cycles in a sampling period */
-	stat->total_time = ACTMON_SAMPLING_PERIOD * tegra->cur_freq;
-
-	return 0;
-}
-
-static int tegra_devfreq_get_target(struct devfreq *devfreq,
-				    unsigned long *freq)
-{
-	struct devfreq_dev_status stat;
-	struct tegra_devfreq *tegra;
-	struct tegra_devfreq_device *dev;
-	unsigned long target_freq = 0;
-	unsigned int i;
-	int err;
-
-	err = devfreq->profile->get_dev_status(devfreq->dev.parent, &stat);
-	if (err)
-		return err;
-
-	tegra = stat.private_data;
-
-	for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) {
-		dev = &tegra->devices[i];
-
-		actmon_update_target(tegra, dev);
-
-		target_freq = max(target_freq, dev->target_freq);
-	}
-
-	*freq = target_freq;
-
-	return 0;
-}
-
-static int tegra_devfreq_event_handler(struct devfreq *devfreq,
-				       unsigned int event, void *data)
-{
-	return 0;
-}
-
-static struct devfreq_governor tegra_devfreq_governor = {
-	.name = "tegra",
-	.get_target_freq = tegra_devfreq_get_target,
-	.event_handler = tegra_devfreq_event_handler,
-};
-
-static struct devfreq_dev_profile tegra_devfreq_profile = {
-	.polling_ms	= 0,
-	.target		= tegra_devfreq_target,
-	.get_dev_status	= tegra_devfreq_get_dev_status,
-};
-
-static int tegra_devfreq_probe(struct platform_device *pdev)
-{
-	struct tegra_devfreq *tegra;
-	struct tegra_devfreq_device *dev;
-	struct resource *res;
-	unsigned long max_freq;
-	unsigned int i;
-	int irq;
-	int err;
-
-	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
-	if (!tegra)
-		return -ENOMEM;
-
-	spin_lock_init(&tegra->lock);
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(&pdev->dev, "Failed to get regs resource\n");
-		return -ENODEV;
-	}
-
-	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(tegra->regs)) {
-		dev_err(&pdev->dev, "Failed to get IO memory\n");
-		return PTR_ERR(tegra->regs);
-	}
-
-	tegra->reset = devm_reset_control_get(&pdev->dev, "actmon");
-	if (IS_ERR(tegra->reset)) {
-		dev_err(&pdev->dev, "Failed to get reset\n");
-		return PTR_ERR(tegra->reset);
-	}
-
-	tegra->clock = devm_clk_get(&pdev->dev, "actmon");
-	if (IS_ERR(tegra->clock)) {
-		dev_err(&pdev->dev, "Failed to get actmon clock\n");
-		return PTR_ERR(tegra->clock);
-	}
-
-	tegra->emc_clock = devm_clk_get(&pdev->dev, "emc");
-	if (IS_ERR(tegra->emc_clock)) {
-		dev_err(&pdev->dev, "Failed to get emc clock\n");
-		return PTR_ERR(tegra->emc_clock);
-	}
-
-	err = of_init_opp_table(&pdev->dev);
-	if (err) {
-		dev_err(&pdev->dev, "Failed to init operating point table\n");
-		return err;
-	}
-
-	tegra->rate_change_nb.notifier_call = tegra_actmon_rate_notify_cb;
-	err = clk_notifier_register(tegra->emc_clock, &tegra->rate_change_nb);
-	if (err) {
-		dev_err(&pdev->dev,
-			"Failed to register rate change notifier\n");
-		return err;
-	}
-
-	reset_control_assert(tegra->reset);
-
-	err = clk_prepare_enable(tegra->clock);
-	if (err) {
-		reset_control_deassert(tegra->reset);
-		return err;
-	}
-
-	reset_control_deassert(tegra->reset);
-
-	max_freq = clk_round_rate(tegra->emc_clock, ULONG_MAX);
-	tegra->max_freq = max_freq / KHZ;
-
-	clk_set_rate(tegra->emc_clock, max_freq);
-
-	tegra->cur_freq = clk_get_rate(tegra->emc_clock) / KHZ;
-
-	writel(ACTMON_SAMPLING_PERIOD - 1,
-	       tegra->regs + ACTMON_GLB_PERIOD_CTRL);
-
-	for (i = 0; i < ARRAY_SIZE(actmon_device_configs); i++) {
-		dev = tegra->devices + i;
-		dev->config = actmon_device_configs + i;
-		dev->regs = tegra->regs + dev->config->offset;
-
-		tegra_actmon_configure_device(tegra, tegra->devices + i);
-	}
-
-	err = devfreq_add_governor(&tegra_devfreq_governor);
-	if (err) {
-		dev_err(&pdev->dev, "Failed to add governor\n");
-		return err;
-	}
-
-	tegra_devfreq_profile.initial_freq = clk_get_rate(tegra->emc_clock);
-	tegra->devfreq = devm_devfreq_add_device(&pdev->dev,
-						 &tegra_devfreq_profile,
-						 "tegra",
-						 NULL);
-
-	irq = platform_get_irq(pdev, 0);
-	err = devm_request_threaded_irq(&pdev->dev, irq, actmon_isr,
-					actmon_thread_isr, IRQF_SHARED,
-					"tegra-devfreq", tegra);
-	if (err) {
-		dev_err(&pdev->dev, "Interrupt request failed\n");
-		return err;
-	}
-
-	platform_set_drvdata(pdev, tegra);
-
-	return 0;
-}
-
-static int tegra_devfreq_remove(struct platform_device *pdev)
-{
-	struct tegra_devfreq *tegra = platform_get_drvdata(pdev);
-
-	clk_notifier_unregister(tegra->emc_clock, &tegra->rate_change_nb);
-
-	clk_disable_unprepare(tegra->clock);
-
-	return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(tegra_devfreq_pm_ops,
-			 tegra_devfreq_suspend,
-			 tegra_devfreq_resume);
-
-static struct of_device_id tegra_devfreq_of_match[] = {
-	{ .compatible = "nvidia,tegra124-actmon" },
-	{ },
-};
-
-static struct platform_driver tegra_devfreq_driver = {
-	.probe	= tegra_devfreq_probe,
-	.remove	= tegra_devfreq_remove,
-	.driver = {
-		.name		= "tegra-devfreq",
-		.owner		= THIS_MODULE,
-		.of_match_table = tegra_devfreq_of_match,
-		.pm		= &tegra_devfreq_pm_ops,
-	},
-};
-module_platform_driver(tegra_devfreq_driver);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("Tegra devfreq driver");
-MODULE_AUTHOR("Tomeu Vizoso <tomeu.vizoso@collabora.com>");
-MODULE_DEVICE_TABLE(of, tegra_devfreq_of_match);