Merge tag 'tegra-for-4.3-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/dt

ARM: tegra: Devicetree changes for v4.3-rc1

Enables CPU frequency scaling on Jetson TK1 and enables the GK20A GPU on
Venice2 and Jetson TK1. This also enables support for the PMU hardware
found on Tegra124, which among other things, can be used for performance
measurements.

* tag 'tegra-for-4.3-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  ARM: tegra: Add gpio-ranges property
  ARM: tegra: Fix AHB base address on Tegra20, Tegra30 and Tegra114
  ARM: tegra: Add Tegra124 PMU support
  ARM: tegra: jetson-tk1: Add GK20A GPU DT node
  ARM: tegra: venice2: Add GK20A GPU DT node
  ARM: tegra: Add IOMMU node to GK20A
  ARM: tegra: Add CPU regulator to the Jetson TK1 device tree
  ARM: tegra: Add entries for cpufreq on Tegra124
  ARM: tegra: Enable the DFLL on the Jetson TK1
  ARM: tegra: Add the DFLL to Tegra124 device tree
  pinctrl: tegra: Only set the gpio range if needed
  clk: tegra: Add the DFLL as a possible parent of the cclk_g clock
  clk: tegra: Save/restore CCLKG_BURST_POLICY on suspend
  clk: tegra: Add Tegra124 DFLL clocksource platform driver
  clk: tegra: Add DFLL DVCO reset control for Tegra124
  clk: tegra: Introduce ability for SoC-specific reset control callbacks
  clk: tegra: Add functions for parsing CVB tables
  clk: tegra: Add closed loop support for the DFLL
  clk: tegra: Add library for the DFLL clock source (open-loop mode)
  clk: tegra: Add binding for the Tegra124 DFLL clocksource

Signed-off-by: Olof Johansson <olof@lixom.net>

10 files changed, 2304 insertions, 9 deletions

diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
index aec862ba7a17..826c325dc2e8 100644
--- a/drivers/clk/tegra/Makefile
+++ b/drivers/clk/tegra/Makefile
@@ -1,5 +1,6 @@
 obj-y					+= clk.o
 obj-y					+= clk-audio-sync.o
+obj-y					+= clk-dfll.o
 obj-y					+= clk-divider.o
 obj-y					+= clk-periph.o
 obj-y					+= clk-periph-gate.o
@@ -16,4 +17,6 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += clk-tegra20.o
 obj-$(CONFIG_ARCH_TEGRA_3x_SOC)         += clk-tegra30.o
 obj-$(CONFIG_ARCH_TEGRA_114_SOC)	+= clk-tegra114.o
 obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= clk-tegra124.o
+obj-$(CONFIG_ARCH_TEGRA_124_SOC)	+= clk-tegra124-dfll-fcpu.o
 obj-$(CONFIG_ARCH_TEGRA_132_SOC)	+= clk-tegra124.o
+obj-y					+= cvb.o
diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c
new file mode 100644
index 000000000000..109a79b95238
--- /dev/null
+++ b/drivers/clk/tegra/clk-dfll.c
@@ -0,0 +1,1755 @@
+/*
+ * clk-dfll.c - Tegra DFLL clock source common code
+ *
+ * Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved.
+ *
+ * Aleksandr Frid <afrid@nvidia.com>
+ * Paul Walmsley <pwalmsley@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * This library is for the DVCO and DFLL IP blocks on the Tegra124
+ * SoC. These IP blocks together are also known at NVIDIA as
+ * "CL-DVFS". To try to avoid confusion, this code refers to them
+ * collectively as the "DFLL."
+ *
+ * The DFLL is a root clocksource which tolerates some amount of
+ * supply voltage noise. Tegra124 uses it to clock the fast CPU
+ * complex when the target CPU speed is above a particular rate. The
+ * DFLL can be operated in either open-loop mode or closed-loop mode.
+ * In open-loop mode, the DFLL generates an output clock appropriate
+ * to the supply voltage. In closed-loop mode, when configured with a
+ * target frequency, the DFLL minimizes supply voltage while
+ * delivering an average frequency equal to the target.
+ *
+ * Devices clocked by the DFLL must be able to tolerate frequency
+ * variation. In the case of the CPU, it's important to note that the
+ * CPU cycle time will vary. This has implications for
+ * performance-measurement code and any code that relies on the CPU
+ * cycle time to delay for a certain length of time.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/seq_file.h>
+
+#include "clk-dfll.h"
+
+/*
+ * DFLL control registers - access via dfll_{readl,writel}
+ */
+
+/* DFLL_CTRL: DFLL control register */
+#define DFLL_CTRL			0x00
+#define DFLL_CTRL_MODE_MASK		0x03
+
+/* DFLL_CONFIG: DFLL sample rate control */
+#define DFLL_CONFIG			0x04
+#define DFLL_CONFIG_DIV_MASK		0xff
+#define DFLL_CONFIG_DIV_PRESCALE	32
+
+/* DFLL_PARAMS: tuning coefficients for closed loop integrator */
+#define DFLL_PARAMS			0x08
+#define DFLL_PARAMS_CG_SCALE		(0x1 << 24)
+#define DFLL_PARAMS_FORCE_MODE_SHIFT	22
+#define DFLL_PARAMS_FORCE_MODE_MASK	(0x3 << DFLL_PARAMS_FORCE_MODE_SHIFT)
+#define DFLL_PARAMS_CF_PARAM_SHIFT	16
+#define DFLL_PARAMS_CF_PARAM_MASK	(0x3f << DFLL_PARAMS_CF_PARAM_SHIFT)
+#define DFLL_PARAMS_CI_PARAM_SHIFT	8
+#define DFLL_PARAMS_CI_PARAM_MASK	(0x7 << DFLL_PARAMS_CI_PARAM_SHIFT)
+#define DFLL_PARAMS_CG_PARAM_SHIFT	0
+#define DFLL_PARAMS_CG_PARAM_MASK	(0xff << DFLL_PARAMS_CG_PARAM_SHIFT)
+
+/* DFLL_TUNE0: delay line configuration register 0 */
+#define DFLL_TUNE0			0x0c
+
+/* DFLL_TUNE1: delay line configuration register 1 */
+#define DFLL_TUNE1			0x10
+
+/* DFLL_FREQ_REQ: target DFLL frequency control */
+#define DFLL_FREQ_REQ			0x14
+#define DFLL_FREQ_REQ_FORCE_ENABLE	(0x1 << 28)
+#define DFLL_FREQ_REQ_FORCE_SHIFT	16
+#define DFLL_FREQ_REQ_FORCE_MASK	(0xfff << DFLL_FREQ_REQ_FORCE_SHIFT)
+#define FORCE_MAX			2047
+#define FORCE_MIN			-2048
+#define DFLL_FREQ_REQ_SCALE_SHIFT	8
+#define DFLL_FREQ_REQ_SCALE_MASK	(0xff << DFLL_FREQ_REQ_SCALE_SHIFT)
+#define DFLL_FREQ_REQ_SCALE_MAX		256
+#define DFLL_FREQ_REQ_FREQ_VALID	(0x1 << 7)
+#define DFLL_FREQ_REQ_MULT_SHIFT	0
+#define DFLL_FREQ_REG_MULT_MASK		(0x7f << DFLL_FREQ_REQ_MULT_SHIFT)
+#define FREQ_MAX			127
+
+/* DFLL_DROOP_CTRL: droop prevention control */
+#define DFLL_DROOP_CTRL			0x1c
+
+/* DFLL_OUTPUT_CFG: closed loop mode control registers */
+/* NOTE: access via dfll_i2c_{readl,writel} */
+#define DFLL_OUTPUT_CFG			0x20
+#define DFLL_OUTPUT_CFG_I2C_ENABLE	(0x1 << 30)
+#define OUT_MASK			0x3f
+#define DFLL_OUTPUT_CFG_SAFE_SHIFT	24
+#define DFLL_OUTPUT_CFG_SAFE_MASK	\
+		(OUT_MASK << DFLL_OUTPUT_CFG_SAFE_SHIFT)
+#define DFLL_OUTPUT_CFG_MAX_SHIFT	16
+#define DFLL_OUTPUT_CFG_MAX_MASK	\
+		(OUT_MASK << DFLL_OUTPUT_CFG_MAX_SHIFT)
+#define DFLL_OUTPUT_CFG_MIN_SHIFT	8
+#define DFLL_OUTPUT_CFG_MIN_MASK	\
+		(OUT_MASK << DFLL_OUTPUT_CFG_MIN_SHIFT)
+#define DFLL_OUTPUT_CFG_PWM_DELTA	(0x1 << 7)
+#define DFLL_OUTPUT_CFG_PWM_ENABLE	(0x1 << 6)
+#define DFLL_OUTPUT_CFG_PWM_DIV_SHIFT	0
+#define DFLL_OUTPUT_CFG_PWM_DIV_MASK	\
+		(OUT_MASK << DFLL_OUTPUT_CFG_PWM_DIV_SHIFT)
+
+/* DFLL_OUTPUT_FORCE: closed loop mode voltage forcing control */
+#define DFLL_OUTPUT_FORCE		0x24
+#define DFLL_OUTPUT_FORCE_ENABLE	(0x1 << 6)
+#define DFLL_OUTPUT_FORCE_VALUE_SHIFT	0
+#define DFLL_OUTPUT_FORCE_VALUE_MASK	\
+		(OUT_MASK << DFLL_OUTPUT_FORCE_VALUE_SHIFT)
+
+/* DFLL_MONITOR_CTRL: internal monitor data source control */
+#define DFLL_MONITOR_CTRL		0x28
+#define DFLL_MONITOR_CTRL_FREQ		6
+
+/* DFLL_MONITOR_DATA: internal monitor data output */
+#define DFLL_MONITOR_DATA		0x2c
+#define DFLL_MONITOR_DATA_NEW_MASK	(0x1 << 16)
+#define DFLL_MONITOR_DATA_VAL_SHIFT	0
+#define DFLL_MONITOR_DATA_VAL_MASK	(0xFFFF << DFLL_MONITOR_DATA_VAL_SHIFT)
+
+/*
+ * I2C output control registers - access via dfll_i2c_{readl,writel}
+ */
+
+/* DFLL_I2C_CFG: I2C controller configuration register */
+#define DFLL_I2C_CFG			0x40
+#define DFLL_I2C_CFG_ARB_ENABLE		(0x1 << 20)
+#define DFLL_I2C_CFG_HS_CODE_SHIFT	16
+#define DFLL_I2C_CFG_HS_CODE_MASK	(0x7 << DFLL_I2C_CFG_HS_CODE_SHIFT)
+#define DFLL_I2C_CFG_PACKET_ENABLE	(0x1 << 15)
+#define DFLL_I2C_CFG_SIZE_SHIFT		12
+#define DFLL_I2C_CFG_SIZE_MASK		(0x7 << DFLL_I2C_CFG_SIZE_SHIFT)
+#define DFLL_I2C_CFG_SLAVE_ADDR_10	(0x1 << 10)
+#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT	1
+#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT	0
+
+/* DFLL_I2C_VDD_REG_ADDR: PMIC I2C address for closed loop mode */
+#define DFLL_I2C_VDD_REG_ADDR		0x44
+
+/* DFLL_I2C_STS: I2C controller status */
+#define DFLL_I2C_STS			0x48
+#define DFLL_I2C_STS_I2C_LAST_SHIFT	1
+#define DFLL_I2C_STS_I2C_REQ_PENDING	0x1
+
+/* DFLL_INTR_STS: DFLL interrupt status register */
+#define DFLL_INTR_STS			0x5c
+
+/* DFLL_INTR_EN: DFLL interrupt enable register */
+#define DFLL_INTR_EN			0x60
+#define DFLL_INTR_MIN_MASK		0x1
+#define DFLL_INTR_MAX_MASK		0x2
+
+/*
+ * Integrated I2C controller registers - relative to td->i2c_controller_base
+ */
+
+/* DFLL_I2C_CLK_DIVISOR: I2C controller clock divisor */
+#define DFLL_I2C_CLK_DIVISOR		0x6c
+#define DFLL_I2C_CLK_DIVISOR_MASK	0xffff
+#define DFLL_I2C_CLK_DIVISOR_FS_SHIFT	16
+#define DFLL_I2C_CLK_DIVISOR_HS_SHIFT	0
+#define DFLL_I2C_CLK_DIVISOR_PREDIV	8
+#define DFLL_I2C_CLK_DIVISOR_HSMODE_PREDIV	12
+
+/*
+ * Other constants
+ */
+
+/* MAX_DFLL_VOLTAGES: number of LUT entries in the DFLL IP block */
+#define MAX_DFLL_VOLTAGES		33
+
+/*
+ * REF_CLK_CYC_PER_DVCO_SAMPLE: the number of ref_clk cycles that the hardware
+ *    integrates the DVCO counter over - used for debug rate monitoring and
+ *    droop control
+ */
+#define REF_CLK_CYC_PER_DVCO_SAMPLE	4
+
+/*
+ * REF_CLOCK_RATE: the DFLL reference clock rate currently supported by this
+ * driver, in Hz
+ */
+#define REF_CLOCK_RATE			51000000UL
+
+#define DVCO_RATE_TO_MULT(rate, ref_rate)	((rate) / ((ref_rate) / 2))
+#define MULT_TO_DVCO_RATE(mult, ref_rate)	((mult) * ((ref_rate) / 2))
+
+/**
+ * enum dfll_ctrl_mode - DFLL hardware operating mode
+ * @DFLL_UNINITIALIZED: (uninitialized state - not in hardware bitfield)
+ * @DFLL_DISABLED: DFLL not generating an output clock
+ * @DFLL_OPEN_LOOP: DVCO running, but DFLL not adjusting voltage
+ * @DFLL_CLOSED_LOOP: DVCO running, and DFLL adjusting voltage to match
+ *		      the requested rate
+ *
+ * The integer corresponding to the last two states, minus one, is
+ * written to the DFLL hardware to change operating modes.
+ */
+enum dfll_ctrl_mode {
+	DFLL_UNINITIALIZED = 0,
+	DFLL_DISABLED = 1,
+	DFLL_OPEN_LOOP = 2,
+	DFLL_CLOSED_LOOP = 3,
+};
+
+/**
+ * enum dfll_tune_range - voltage range that the driver believes it's in
+ * @DFLL_TUNE_UNINITIALIZED: DFLL tuning not yet programmed
+ * @DFLL_TUNE_LOW: DFLL in the low-voltage range (or open-loop mode)
+ *
+ * Some DFLL tuning parameters may need to change depending on the
+ * DVCO's voltage; these states represent the ranges that the driver
+ * supports. These are software states; these values are never
+ * written into registers.
+ */
+enum dfll_tune_range {
+	DFLL_TUNE_UNINITIALIZED = 0,
+	DFLL_TUNE_LOW = 1,
+};
+
+/**
+ * struct dfll_rate_req - target DFLL rate request data
+ * @rate: target frequency, after the postscaling
+ * @dvco_target_rate: target frequency, after the postscaling
+ * @lut_index: LUT index at which voltage the dvco_target_rate will be reached
+ * @mult_bits: value to program to the MULT bits of the DFLL_FREQ_REQ register
+ * @scale_bits: value to program to the SCALE bits of the DFLL_FREQ_REQ register
+ */
+struct dfll_rate_req {
+	unsigned long rate;
+	unsigned long dvco_target_rate;
+	int lut_index;
+	u8 mult_bits;
+	u8 scale_bits;
+};
+
+struct tegra_dfll {
+	struct device			*dev;
+	struct tegra_dfll_soc_data	*soc;
+
+	void __iomem			*base;
+	void __iomem			*i2c_base;
+	void __iomem			*i2c_controller_base;
+	void __iomem			*lut_base;
+
+	struct regulator		*vdd_reg;
+	struct clk			*soc_clk;
+	struct clk			*ref_clk;
+	struct clk			*i2c_clk;
+	struct clk			*dfll_clk;
+	struct reset_control		*dvco_rst;
+	unsigned long			ref_rate;
+	unsigned long			i2c_clk_rate;
+	unsigned long			dvco_rate_min;
+
+	enum dfll_ctrl_mode		mode;
+	enum dfll_tune_range		tune_range;
+	struct dentry			*debugfs_dir;
+	struct clk_hw			dfll_clk_hw;
+	const char			*output_clock_name;
+	struct dfll_rate_req		last_req;
+	unsigned long			last_unrounded_rate;
+
+	/* Parameters from DT */
+	u32				droop_ctrl;
+	u32				sample_rate;
+	u32				force_mode;
+	u32				cf;
+	u32				ci;
+	u32				cg;
+	bool				cg_scale;
+
+	/* I2C interface parameters */
+	u32				i2c_fs_rate;
+	u32				i2c_reg;
+	u32				i2c_slave_addr;
+
+	/* i2c_lut array entries are regulator framework selectors */
+	unsigned			i2c_lut[MAX_DFLL_VOLTAGES];
+	int				i2c_lut_size;
+	u8				lut_min, lut_max, lut_safe;
+};
+
+#define clk_hw_to_dfll(_hw) container_of(_hw, struct tegra_dfll, dfll_clk_hw)
+
+/* mode_name: map numeric DFLL modes to names for friendly console messages */
+static const char * const mode_name[] = {
+	[DFLL_UNINITIALIZED] = "uninitialized",
+	[DFLL_DISABLED] = "disabled",
+	[DFLL_OPEN_LOOP] = "open_loop",
+	[DFLL_CLOSED_LOOP] = "closed_loop",
+};
+
+/*
+ * Register accessors
+ */
+
+static inline u32 dfll_readl(struct tegra_dfll *td, u32 offs)
+{
+	return __raw_readl(td->base + offs);
+}
+
+static inline void dfll_writel(struct tegra_dfll *td, u32 val, u32 offs)
+{
+	WARN_ON(offs >= DFLL_I2C_CFG);
+	__raw_writel(val, td->base + offs);
+}
+
+static inline void dfll_wmb(struct tegra_dfll *td)
+{
+	dfll_readl(td, DFLL_CTRL);
+}
+
+/* I2C output control registers - for addresses above DFLL_I2C_CFG */
+
+static inline u32 dfll_i2c_readl(struct tegra_dfll *td, u32 offs)
+{
+	return __raw_readl(td->i2c_base + offs);
+}
+
+static inline void dfll_i2c_writel(struct tegra_dfll *td, u32 val, u32 offs)
+{
+	__raw_writel(val, td->i2c_base + offs);
+}
+
+static inline void dfll_i2c_wmb(struct tegra_dfll *td)
+{
+	dfll_i2c_readl(td, DFLL_I2C_CFG);
+}
+
+/**
+ * dfll_is_running - is the DFLL currently generating a clock?
+ * @td: DFLL instance
+ *
+ * If the DFLL is currently generating an output clock signal, return
+ * true; otherwise return false.
+ */
+static bool dfll_is_running(struct tegra_dfll *td)
+{
+	return td->mode >= DFLL_OPEN_LOOP;
+}
+
+/*
+ * Runtime PM suspend/resume callbacks
+ */
+
+/**
+ * tegra_dfll_runtime_resume - enable all clocks needed by the DFLL
+ * @dev: DFLL device *
+ *
+ * Enable all clocks needed by the DFLL. Assumes that clk_prepare()
+ * has already been called on all the clocks.
+ *
+ * XXX Should also handle context restore when returning from off.
+ */
+int tegra_dfll_runtime_resume(struct device *dev)
+{
+	struct tegra_dfll *td = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(td->ref_clk);
+	if (ret) {
+		dev_err(dev, "could not enable ref clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_enable(td->soc_clk);
+	if (ret) {
+		dev_err(dev, "could not enable register clock: %d\n", ret);
+		clk_disable(td->ref_clk);
+		return ret;
+	}
+
+	ret = clk_enable(td->i2c_clk);
+	if (ret) {
+		dev_err(dev, "could not enable i2c clock: %d\n", ret);
+		clk_disable(td->soc_clk);
+		clk_disable(td->ref_clk);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_dfll_runtime_resume);
+
+/**
+ * tegra_dfll_runtime_suspend - disable all clocks needed by the DFLL
+ * @dev: DFLL device *
+ *
+ * Disable all clocks needed by the DFLL. Assumes that other code
+ * will later call clk_unprepare().
+ */
+int tegra_dfll_runtime_suspend(struct device *dev)
+{
+	struct tegra_dfll *td = dev_get_drvdata(dev);
+
+	clk_disable(td->ref_clk);
+	clk_disable(td->soc_clk);
+	clk_disable(td->i2c_clk);
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_dfll_runtime_suspend);
+
+/*
+ * DFLL tuning operations (per-voltage-range tuning settings)
+ */
+
+/**
+ * dfll_tune_low - tune to DFLL and CPU settings valid for any voltage
+ * @td: DFLL instance
+ *
+ * Tune the DFLL oscillator parameters and the CPU clock shaper for
+ * the low-voltage range. These settings are valid for any voltage,
+ * but may not be optimal.
+ */
+static void dfll_tune_low(struct tegra_dfll *td)
+{
+	td->tune_range = DFLL_TUNE_LOW;
+
+	dfll_writel(td, td->soc->tune0_low, DFLL_TUNE0);
+	dfll_writel(td, td->soc->tune1, DFLL_TUNE1);
+	dfll_wmb(td);
+
+	if (td->soc->set_clock_trimmers_low)
+		td->soc->set_clock_trimmers_low();
+}
+
+/*
+ * Output clock scaler helpers
+ */
+
+/**
+ * dfll_scale_dvco_rate - calculate scaled rate from the DVCO rate
+ * @scale_bits: clock scaler value (bits in the DFLL_FREQ_REQ_SCALE field)
+ * @dvco_rate: the DVCO rate
+ *
+ * Apply the same scaling formula that the DFLL hardware uses to scale
+ * the DVCO rate.
+ */
+static unsigned long dfll_scale_dvco_rate(int scale_bits,
+					  unsigned long dvco_rate)
+{
+	return (u64)dvco_rate * (scale_bits + 1) / DFLL_FREQ_REQ_SCALE_MAX;
+}
+
+/*
+ * Monitor control
+ */
+
+/**
+ * dfll_calc_monitored_rate - convert DFLL_MONITOR_DATA_VAL rate into real freq
+ * @monitor_data: value read from the DFLL_MONITOR_DATA_VAL bitfield
+ * @ref_rate: DFLL reference clock rate
+ *
+ * Convert @monitor_data from DFLL_MONITOR_DATA_VAL units into cycles
+ * per second. Returns the converted value.
+ */
+static u64 dfll_calc_monitored_rate(u32 monitor_data,
+				    unsigned long ref_rate)
+{
+	return monitor_data * (ref_rate / REF_CLK_CYC_PER_DVCO_SAMPLE);
+}
+
+/**
+ * dfll_read_monitor_rate - return the DFLL's output rate from internal monitor
+ * @td: DFLL instance
+ *
+ * If the DFLL is enabled, return the last rate reported by the DFLL's
+ * internal monitoring hardware. This works in both open-loop and
+ * closed-loop mode, and takes the output scaler setting into account.
+ * Assumes that the monitor was programmed to monitor frequency before
+ * the sample period started. If the driver believes that the DFLL is
+ * currently uninitialized or disabled, it will return 0, since
+ * otherwise the DFLL monitor data register will return the last
+ * measured rate from when the DFLL was active.
+ */
+static u64 dfll_read_monitor_rate(struct tegra_dfll *td)
+{
+	u32 v, s;
+	u64 pre_scaler_rate, post_scaler_rate;
+
+	if (!dfll_is_running(td))
+		return 0;
+
+	v = dfll_readl(td, DFLL_MONITOR_DATA);
+	v = (v & DFLL_MONITOR_DATA_VAL_MASK) >> DFLL_MONITOR_DATA_VAL_SHIFT;
+	pre_scaler_rate = dfll_calc_monitored_rate(v, td->ref_rate);
+
+	s = dfll_readl(td, DFLL_FREQ_REQ);
+	s = (s & DFLL_FREQ_REQ_SCALE_MASK) >> DFLL_FREQ_REQ_SCALE_SHIFT;
+	post_scaler_rate = dfll_scale_dvco_rate(s, pre_scaler_rate);
+
+	return post_scaler_rate;
+}
+
+/*
+ * DFLL mode switching
+ */
+
+/**
+ * dfll_set_mode - change the DFLL control mode
+ * @td: DFLL instance
+ * @mode: DFLL control mode (see enum dfll_ctrl_mode)
+ *
+ * Change the DFLL's operating mode between disabled, open-loop mode,
+ * and closed-loop mode, or vice versa.
+ */
+static void dfll_set_mode(struct tegra_dfll *td,
+			  enum dfll_ctrl_mode mode)
+{
+	td->mode = mode;
+	dfll_writel(td, mode - 1, DFLL_CTRL);
+	dfll_wmb(td);
+}
+
+/*
+ * DFLL-to-I2C controller interface
+ */
+
+/**
+ * dfll_i2c_set_output_enabled - enable/disable I2C PMIC voltage requests
+ * @td: DFLL instance
+ * @enable: whether to enable or disable the I2C voltage requests
+ *
+ * Set the master enable control for I2C control value updates. If disabled,
+ * then I2C control messages are inhibited, regardless of the DFLL mode.
+ */
+static int dfll_i2c_set_output_enabled(struct tegra_dfll *td, bool enable)
+{
+	u32 val;
+
+	val = dfll_i2c_readl(td, DFLL_OUTPUT_CFG);
+
+	if (enable)
+		val |= DFLL_OUTPUT_CFG_I2C_ENABLE;
+	else
+		val &= ~DFLL_OUTPUT_CFG_I2C_ENABLE;
+
+	dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG);
+	dfll_i2c_wmb(td);
+
+	return 0;
+}
+
+/**
+ * dfll_load_lut - load the voltage lookup table
+ * @td: struct tegra_dfll *
+ *
+ * Load the voltage-to-PMIC register value lookup table into the DFLL
+ * IP block memory. Look-up tables can be loaded at any time.
+ */
+static void dfll_load_i2c_lut(struct tegra_dfll *td)
+{
+	int i, lut_index;
+	u32 val;
+
+	for (i = 0; i < MAX_DFLL_VOLTAGES; i++) {
+		if (i < td->lut_min)
+			lut_index = td->lut_min;
+		else if (i > td->lut_max)
+			lut_index = td->lut_max;
+		else
+			lut_index = i;
+
+		  val = regulator_list_hardware_vsel(td->vdd_reg,
+						     td->i2c_lut[lut_index]);
+		__raw_writel(val, td->lut_base + i * 4);
+	}
+
+	dfll_i2c_wmb(td);
+}
+
+/**
+ * dfll_init_i2c_if - set up the DFLL's DFLL-I2C interface
+ * @td: DFLL instance
+ *
+ * During DFLL driver initialization, program the DFLL-I2C interface
+ * with the PMU slave address, vdd register offset, and transfer mode.
+ * This data is used by the DFLL to automatically construct I2C
+ * voltage-set commands, which are then passed to the DFLL's internal
+ * I2C controller.
+ */
+static void dfll_init_i2c_if(struct tegra_dfll *td)
+{
+	u32 val;
+
+	if (td->i2c_slave_addr > 0x7f) {
+		val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT;
+		val |= DFLL_I2C_CFG_SLAVE_ADDR_10;
+	} else {
+		val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT;
+	}
+	val |= DFLL_I2C_CFG_SIZE_MASK;
+	val |= DFLL_I2C_CFG_ARB_ENABLE;
+	dfll_i2c_writel(td, val, DFLL_I2C_CFG);
+
+	dfll_i2c_writel(td, td->i2c_reg, DFLL_I2C_VDD_REG_ADDR);
+
+	val = DIV_ROUND_UP(td->i2c_clk_rate, td->i2c_fs_rate * 8);
+	BUG_ON(!val || (val > DFLL_I2C_CLK_DIVISOR_MASK));
+	val = (val - 1) << DFLL_I2C_CLK_DIVISOR_FS_SHIFT;
+
+	/* default hs divisor just in case */
+	val |= 1 << DFLL_I2C_CLK_DIVISOR_HS_SHIFT;
+	__raw_writel(val, td->i2c_controller_base + DFLL_I2C_CLK_DIVISOR);
+	dfll_i2c_wmb(td);
+}
+
+/**
+ * dfll_init_out_if - prepare DFLL-to-PMIC interface
+ * @td: DFLL instance
+ *
+ * During DFLL driver initialization or resume from context loss,
+ * disable the I2C command output to the PMIC, set safe voltage and
+ * output limits, and disable and clear limit interrupts.
+ */
+static void dfll_init_out_if(struct tegra_dfll *td)
+{
+	u32 val;
+
+	td->lut_min = 0;
+	td->lut_max = td->i2c_lut_size - 1;
+	td->lut_safe = td->lut_min + 1;
+
+	dfll_i2c_writel(td, 0, DFLL_OUTPUT_CFG);
+	val = (td->lut_safe << DFLL_OUTPUT_CFG_SAFE_SHIFT) |
+		(td->lut_max << DFLL_OUTPUT_CFG_MAX_SHIFT) |
+		(td->lut_min << DFLL_OUTPUT_CFG_MIN_SHIFT);
+	dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG);
+	dfll_i2c_wmb(td);
+
+	dfll_writel(td, 0, DFLL_OUTPUT_FORCE);
+	dfll_i2c_writel(td, 0, DFLL_INTR_EN);
+	dfll_i2c_writel(td, DFLL_INTR_MAX_MASK | DFLL_INTR_MIN_MASK,
+			DFLL_INTR_STS);
+
+	dfll_load_i2c_lut(td);
+	dfll_init_i2c_if(td);
+}
+
+/*
+ * Set/get the DFLL's targeted output clock rate
+ */
+
+/**
+ * find_lut_index_for_rate - determine I2C LUT index for given DFLL rate
+ * @td: DFLL instance
+ * @rate: clock rate
+ *
+ * Determines the index of a I2C LUT entry for a voltage that approximately
+ * produces the given DFLL clock rate. This is used when forcing a value
+ * to the integrator during rate changes. Returns -ENOENT if a suitable
+ * LUT index is not found.
+ */
+static int find_lut_index_for_rate(struct tegra_dfll *td, unsigned long rate)
+{
+	struct dev_pm_opp *opp;
+	int i, uv;
+
+	opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
+	if (IS_ERR(opp))
+		return PTR_ERR(opp);
+	uv = dev_pm_opp_get_voltage(opp);
+
+	for (i = 0; i < td->i2c_lut_size; i++) {
+		if (regulator_list_voltage(td->vdd_reg, td->i2c_lut[i]) == uv)
+			return i;
+	}
+
+	return -ENOENT;
+}
+
+/**
+ * dfll_calculate_rate_request - calculate DFLL parameters for a given rate
+ * @td: DFLL instance
+ * @req: DFLL-rate-request structure
+ * @rate: the desired DFLL rate
+ *
+ * Populate the DFLL-rate-request record @req fields with the scale_bits
+ * and mult_bits fields, based on the target input rate. Returns 0 upon
+ * success, or -EINVAL if the requested rate in req->rate is too high
+ * or low for the DFLL to generate.
+ */
+static int dfll_calculate_rate_request(struct tegra_dfll *td,
+				       struct dfll_rate_req *req,
+				       unsigned long rate)
+{
+	u32 val;
+
+	/*
+	 * If requested rate is below the minimum DVCO rate, active the scaler.
+	 * In the future the DVCO minimum voltage should be selected based on
+	 * chip temperature and the actual minimum rate should be calibrated
+	 * at runtime.
+	 */
+	req->scale_bits = DFLL_FREQ_REQ_SCALE_MAX - 1;
+	if (rate < td->dvco_rate_min) {
+		int scale;
+
+		scale = DIV_ROUND_CLOSEST(rate / 1000 * DFLL_FREQ_REQ_SCALE_MAX,
+					  td->dvco_rate_min / 1000);
+		if (!scale) {
+			dev_err(td->dev, "%s: Rate %lu is too low\n",
+				__func__, rate);
+			return -EINVAL;
+		}
+		req->scale_bits = scale - 1;
+		rate = td->dvco_rate_min;
+	}
+
+	/* Convert requested rate into frequency request and scale settings */
+	val = DVCO_RATE_TO_MULT(rate, td->ref_rate);
+	if (val > FREQ_MAX) {
+		dev_err(td->dev, "%s: Rate %lu is above dfll range\n",
+			__func__, rate);
+		return -EINVAL;
+	}
+	req->mult_bits = val;
+	req->dvco_target_rate = MULT_TO_DVCO_RATE(req->mult_bits, td->ref_rate);
+	req->rate = dfll_scale_dvco_rate(req->scale_bits,
+					 req->dvco_target_rate);
+	req->lut_index = find_lut_index_for_rate(td, req->dvco_target_rate);
+	if (req->lut_index < 0)
+		return req->lut_index;
+
+	return 0;
+}
+
+/**
+ * dfll_set_frequency_request - start the frequency change operation
+ * @td: DFLL instance
+ * @req: rate request structure
+ *
+ * Tell the DFLL to try to change its output frequency to the
+ * frequency represented by @req. DFLL must be in closed-loop mode.
+ */
+static void dfll_set_frequency_request(struct tegra_dfll *td,
+				       struct dfll_rate_req *req)
+{
+	u32 val = 0;
+	int force_val;
+	int coef = 128; /* FIXME: td->cg_scale? */;
+
+	force_val = (req->lut_index - td->lut_safe) * coef / td->cg;
+	force_val = clamp(force_val, FORCE_MIN, FORCE_MAX);
+
+	val |= req->mult_bits << DFLL_FREQ_REQ_MULT_SHIFT;
+	val |= req->scale_bits << DFLL_FREQ_REQ_SCALE_SHIFT;
+	val |= ((u32)force_val << DFLL_FREQ_REQ_FORCE_SHIFT) &
+		DFLL_FREQ_REQ_FORCE_MASK;
+	val |= DFLL_FREQ_REQ_FREQ_VALID | DFLL_FREQ_REQ_FORCE_ENABLE;
+
+	dfll_writel(td, val, DFLL_FREQ_REQ);
+	dfll_wmb(td);
+}
+
+/**
+ * tegra_dfll_request_rate - set the next rate for the DFLL to tune to
+ * @td: DFLL instance
+ * @rate: clock rate to target
+ *
+ * Convert the requested clock rate @rate into the DFLL control logic
+ * settings. In closed-loop mode, update new settings immediately to
+ * adjust DFLL output rate accordingly. Otherwise, just save them
+ * until the next switch to closed loop. Returns 0 upon success,
+ * -EPERM if the DFLL driver has not yet been initialized, or -EINVAL
+ * if @rate is outside the DFLL's tunable range.
+ */
+static int dfll_request_rate(struct tegra_dfll *td, unsigned long rate)
+{
+	int ret;
+	struct dfll_rate_req req;
+
+	if (td->mode == DFLL_UNINITIALIZED) {
+		dev_err(td->dev, "%s: Cannot set DFLL rate in %s mode\n",
+			__func__, mode_name[td->mode]);
+		return -EPERM;
+	}
+
+	ret = dfll_calculate_rate_request(td, &req, rate);
+	if (ret)
+		return ret;
+
+	td->last_unrounded_rate = rate;
+	td->last_req = req;
+
+	if (td->mode == DFLL_CLOSED_LOOP)
+		dfll_set_frequency_request(td, &td->last_req);
+
+	return 0;
+}
+
+/*
+ * DFLL enable/disable & open-loop <-> closed-loop transitions
+ */
+
+/**
+ * dfll_disable - switch from open-loop mode to disabled mode
+ * @td: DFLL instance
+ *
+ * Switch from OPEN_LOOP state to DISABLED state. Returns 0 upon success
+ * or -EPERM if the DFLL is not currently in open-loop mode.
+ */
+static int dfll_disable(struct tegra_dfll *td)
+{
+	if (td->mode != DFLL_OPEN_LOOP) {
+		dev_err(td->dev, "cannot disable DFLL in %s mode\n",
+			mode_name[td->mode]);
+		return -EINVAL;
+	}
+
+	dfll_set_mode(td, DFLL_DISABLED);
+	pm_runtime_put_sync(td->dev);
+
+	return 0;
+}
+
+/**
+ * dfll_enable - switch a disabled DFLL to open-loop mode
+ * @td: DFLL instance
+ *
+ * Switch from DISABLED state to OPEN_LOOP state. Returns 0 upon success
+ * or -EPERM if the DFLL is not currently disabled.
+ */
+static int dfll_enable(struct tegra_dfll *td)
+{
+	if (td->mode != DFLL_DISABLED) {
+		dev_err(td->dev, "cannot enable DFLL in %s mode\n",
+			mode_name[td->mode]);
+		return -EPERM;
+	}
+
+	pm_runtime_get_sync(td->dev);
+	dfll_set_mode(td, DFLL_OPEN_LOOP);
+
+	return 0;
+}
+
+/**
+ * dfll_set_open_loop_config - prepare to switch to open-loop mode
+ * @td: DFLL instance
+ *
+ * Prepare to switch the DFLL to open-loop mode. This switches the
+ * DFLL to the low-voltage tuning range, ensures that I2C output
+ * forcing is disabled, and disables the output clock rate scaler.
+ * The DFLL's low-voltage tuning range parameters must be
+ * characterized to keep the downstream device stable at any DVCO
+ * input voltage. No return value.
+ */
+static void dfll_set_open_loop_config(struct tegra_dfll *td)
+{
+	u32 val;
+
+	/* always tune low (safe) in open loop */
+	if (td->tune_range != DFLL_TUNE_LOW)
+		dfll_tune_low(td);
+
+	val = dfll_readl(td, DFLL_FREQ_REQ);
+	val |= DFLL_FREQ_REQ_SCALE_MASK;
+	val &= ~DFLL_FREQ_REQ_FORCE_ENABLE;
+	dfll_writel(td, val, DFLL_FREQ_REQ);
+	dfll_wmb(td);
+}
+
+/**
+ * tegra_dfll_lock - switch from open-loop to closed-loop mode
+ * @td: DFLL instance
+ *
+ * Switch from OPEN_LOOP state to CLOSED_LOOP state. Returns 0 upon success,
+ * -EINVAL if the DFLL's target rate hasn't been set yet, or -EPERM if the
+ * DFLL is not currently in open-loop mode.
+ */
+static int dfll_lock(struct tegra_dfll *td)
+{
+	struct dfll_rate_req *req = &td->last_req;
+
+	switch (td->mode) {
+	case DFLL_CLOSED_LOOP:
+		return 0;
+
+	case DFLL_OPEN_LOOP:
+		if (req->rate == 0) {
+			dev_err(td->dev, "%s: Cannot lock DFLL at rate 0\n",
+				__func__);
+			return -EINVAL;
+		}
+
+		dfll_i2c_set_output_enabled(td, true);
+		dfll_set_mode(td, DFLL_CLOSED_LOOP);
+		dfll_set_frequency_request(td, req);
+		return 0;
+
+	default:
+		BUG_ON(td->mode > DFLL_CLOSED_LOOP);
+		dev_err(td->dev, "%s: Cannot lock DFLL in %s mode\n",
+			__func__, mode_name[td->mode]);
+		return -EPERM;
+	}
+}
+
+/**
+ * tegra_dfll_unlock - switch from closed-loop to open-loop mode
+ * @td: DFLL instance
+ *
+ * Switch from CLOSED_LOOP state to OPEN_LOOP state. Returns 0 upon success,
+ * or -EPERM if the DFLL is not currently in open-loop mode.
+ */
+static int dfll_unlock(struct tegra_dfll *td)
+{
+	switch (td->mode) {
+	case DFLL_CLOSED_LOOP:
+		dfll_set_open_loop_config(td);
+		dfll_set_mode(td, DFLL_OPEN_LOOP);
+		dfll_i2c_set_output_enabled(td, false);
+		return 0;
+
+	case DFLL_OPEN_LOOP:
+		return 0;
+
+	default:
+		BUG_ON(td->mode > DFLL_CLOSED_LOOP);
+		dev_err(td->dev, "%s: Cannot unlock DFLL in %s mode\n",
+			__func__, mode_name[td->mode]);
+		return -EPERM;
+	}
+}
+
+/*
+ * Clock framework integration
+ *
+ * When the DFLL is being controlled by the CCF, always enter closed loop
+ * mode when the clk is enabled. This requires that a DFLL rate request
+ * has been set beforehand, which implies that a clk_set_rate() call is
+ * always required before a clk_enable().
+ */
+
+static int dfll_clk_is_enabled(struct clk_hw *hw)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+
+	return dfll_is_running(td);
+}
+
+static int dfll_clk_enable(struct clk_hw *hw)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+	int ret;
+
+	ret = dfll_enable(td);
+	if (ret)
+		return ret;
+
+	ret = dfll_lock(td);
+	if (ret)
+		dfll_disable(td);
+
+	return ret;
+}
+
+static void dfll_clk_disable(struct clk_hw *hw)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+	int ret;
+
+	ret = dfll_unlock(td);
+	if (!ret)
+		dfll_disable(td);
+}
+
+static unsigned long dfll_clk_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+
+	return td->last_unrounded_rate;
+}
+
+static long dfll_clk_round_rate(struct clk_hw *hw,
+				unsigned long rate,
+				unsigned long *parent_rate)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+	struct dfll_rate_req req;
+	int ret;
+
+	ret = dfll_calculate_rate_request(td, &req, rate);
+	if (ret)
+		return ret;
+
+	/*
+	 * Don't return the rounded rate, since it doesn't really matter as
+	 * the output rate will be voltage controlled anyway, and cpufreq
+	 * freaks out if any rounding happens.
+	 */
+	return rate;
+}
+
+static int dfll_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+			     unsigned long parent_rate)
+{
+	struct tegra_dfll *td = clk_hw_to_dfll(hw);
+
+	return dfll_request_rate(td, rate);
+}
+
+static const struct clk_ops dfll_clk_ops = {
+	.is_enabled	= dfll_clk_is_enabled,
+	.enable		= dfll_clk_enable,
+	.disable	= dfll_clk_disable,
+	.recalc_rate	= dfll_clk_recalc_rate,
+	.round_rate	= dfll_clk_round_rate,
+	.set_rate	= dfll_clk_set_rate,
+};
+
+static struct clk_init_data dfll_clk_init_data = {
+	.flags		= CLK_IS_ROOT,
+	.ops		= &dfll_clk_ops,
+	.num_parents	= 0,
+};
+
+/**
+ * dfll_register_clk - register the DFLL output clock with the clock framework
+ * @td: DFLL instance
+ *
+ * Register the DFLL's output clock with the Linux clock framework and register
+ * the DFLL driver as an OF clock provider. Returns 0 upon success or -EINVAL
+ * or -ENOMEM upon failure.
+ */
+static int dfll_register_clk(struct tegra_dfll *td)
+{
+	int ret;
+
+	dfll_clk_init_data.name = td->output_clock_name;
+	td->dfll_clk_hw.init = &dfll_clk_init_data;
+
+	td->dfll_clk = clk_register(td->dev, &td->dfll_clk_hw);
+	if (IS_ERR(td->dfll_clk)) {
+		dev_err(td->dev, "DFLL clock registration error\n");
+		return -EINVAL;
+	}
+
+	ret = of_clk_add_provider(td->dev->of_node, of_clk_src_simple_get,
+				  td->dfll_clk);
+	if (ret) {
+		dev_err(td->dev, "of_clk_add_provider() failed\n");
+
+		clk_unregister(td->dfll_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * dfll_unregister_clk - unregister the DFLL output clock
+ * @td: DFLL instance
+ *
+ * Unregister the DFLL's output clock from the Linux clock framework
+ * and from clkdev. No return value.
+ */
+static void dfll_unregister_clk(struct tegra_dfll *td)
+{
+	of_clk_del_provider(td->dev->of_node);
+	clk_unregister(td->dfll_clk);
+	td->dfll_clk = NULL;
+}
+
+/*
+ * Debugfs interface
+ */
+
+#ifdef CONFIG_DEBUG_FS
+
+static int attr_enable_get(void *data, u64 *val)
+{
+	struct tegra_dfll *td = data;
+
+	*val = dfll_is_running(td);
+
+	return 0;
+}
+static int attr_enable_set(void *data, u64 val)
+{
+	struct tegra_dfll *td = data;
+
+	return val ? dfll_enable(td) : dfll_disable(td);
+}
+DEFINE_SIMPLE_ATTRIBUTE(enable_fops, attr_enable_get, attr_enable_set,
+			"%llu\n");
+
+static int attr_lock_get(void *data, u64 *val)
+{
+	struct tegra_dfll *td = data;
+
+	*val = (td->mode == DFLL_CLOSED_LOOP);
+
+	return 0;
+}
+static int attr_lock_set(void *data, u64 val)
+{
+	struct tegra_dfll *td = data;
+
+	return val ? dfll_lock(td) :  dfll_unlock(td);
+}
+DEFINE_SIMPLE_ATTRIBUTE(lock_fops, attr_lock_get, attr_lock_set,
+			"%llu\n");
+
+static int attr_rate_get(void *data, u64 *val)
+{
+	struct tegra_dfll *td = data;
+
+	*val = dfll_read_monitor_rate(td);
+
+	return 0;
+}
+
+static int attr_rate_set(void *data, u64 val)
+{
+	struct tegra_dfll *td = data;
+
+	return dfll_request_rate(td, val);
+}
+DEFINE_SIMPLE_ATTRIBUTE(rate_fops, attr_rate_get, attr_rate_set, "%llu\n");
+
+static int attr_registers_show(struct seq_file *s, void *data)
+{
+	u32 val, offs;
+	struct tegra_dfll *td = s->private;
+
+	seq_puts(s, "CONTROL REGISTERS:\n");
+	for (offs = 0; offs <= DFLL_MONITOR_DATA; offs += 4) {
+		if (offs == DFLL_OUTPUT_CFG)
+			val = dfll_i2c_readl(td, offs);
+		else
+			val = dfll_readl(td, offs);
+		seq_printf(s, "[0x%02x] = 0x%08x\n", offs, val);
+	}
+
+	seq_puts(s, "\nI2C and INTR REGISTERS:\n");
+	for (offs = DFLL_I2C_CFG; offs <= DFLL_I2C_STS; offs += 4)
+		seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
+			   dfll_i2c_readl(td, offs));
+	for (offs = DFLL_INTR_STS; offs <= DFLL_INTR_EN; offs += 4)
+		seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
+			   dfll_i2c_readl(td, offs));
+
+	seq_puts(s, "\nINTEGRATED I2C CONTROLLER REGISTERS:\n");
+	offs = DFLL_I2C_CLK_DIVISOR;
+	seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
+		   __raw_readl(td->i2c_controller_base + offs));
+
+	seq_puts(s, "\nLUT:\n");
+	for (offs = 0; offs <  4 * MAX_DFLL_VOLTAGES; offs += 4)
+		seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
+			   __raw_readl(td->lut_base + offs));
+
+	return 0;
+}
+
+static int attr_registers_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, attr_registers_show, inode->i_private);
+}
+
+static const struct file_operations attr_registers_fops = {
+	.open		= attr_registers_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int dfll_debug_init(struct tegra_dfll *td)
+{
+	int ret;
+
+	if (!td || (td->mode == DFLL_UNINITIALIZED))
+		return 0;
+
+	td->debugfs_dir = debugfs_create_dir("tegra_dfll_fcpu", NULL);
+	if (!td->debugfs_dir)
+		return -ENOMEM;
+
+	ret = -ENOMEM;
+
+	if (!debugfs_create_file("enable", S_IRUGO | S_IWUSR,
+				 td->debugfs_dir, td, &enable_fops))
+		goto err_out;
+
+	if (!debugfs_create_file("lock", S_IRUGO,
+				 td->debugfs_dir, td, &lock_fops))
+		goto err_out;
+
+	if (!debugfs_create_file("rate", S_IRUGO,
+				 td->debugfs_dir, td, &rate_fops))
+		goto err_out;
+
+	if (!debugfs_create_file("registers", S_IRUGO,
+				 td->debugfs_dir, td, &attr_registers_fops))
+		goto err_out;
+
+	return 0;
+
+err_out:
+	debugfs_remove_recursive(td->debugfs_dir);
+	return ret;
+}
+
+#endif /* CONFIG_DEBUG_FS */
+
+/*
+ * DFLL initialization
+ */
+
+/**
+ * dfll_set_default_params - program non-output related DFLL parameters
+ * @td: DFLL instance
+ *
+ * During DFLL driver initialization or resume from context loss,
+ * program parameters for the closed loop integrator, DVCO tuning,
+ * voltage droop control and monitor control.
+ */
+static void dfll_set_default_params(struct tegra_dfll *td)
+{
+	u32 val;
+
+	val = DIV_ROUND_UP(td->ref_rate, td->sample_rate * 32);
+	BUG_ON(val > DFLL_CONFIG_DIV_MASK);
+	dfll_writel(td, val, DFLL_CONFIG);
+
+	val = (td->force_mode << DFLL_PARAMS_FORCE_MODE_SHIFT) |
+		(td->cf << DFLL_PARAMS_CF_PARAM_SHIFT) |
+		(td->ci << DFLL_PARAMS_CI_PARAM_SHIFT) |
+		(td->cg << DFLL_PARAMS_CG_PARAM_SHIFT) |
+		(td->cg_scale ? DFLL_PARAMS_CG_SCALE : 0);
+	dfll_writel(td, val, DFLL_PARAMS);
+
+	dfll_tune_low(td);
+	dfll_writel(td, td->droop_ctrl, DFLL_DROOP_CTRL);
+	dfll_writel(td, DFLL_MONITOR_CTRL_FREQ, DFLL_MONITOR_CTRL);
+}
+
+/**
+ * dfll_init_clks - clk_get() the DFLL source clocks
+ * @td: DFLL instance
+ *
+ * Call clk_get() on the DFLL source clocks and save the pointers for later
+ * use. Returns 0 upon success or error (see devm_clk_get) if one or more
+ * of the clocks couldn't be looked up.
+ */
+static int dfll_init_clks(struct tegra_dfll *td)
+{
+	td->ref_clk = devm_clk_get(td->dev, "ref");
+	if (IS_ERR(td->ref_clk)) {
+		dev_err(td->dev, "missing ref clock\n");
+		return PTR_ERR(td->ref_clk);
+	}
+
+	td->soc_clk = devm_clk_get(td->dev, "soc");
+	if (IS_ERR(td->soc_clk)) {
+		dev_err(td->dev, "missing soc clock\n");
+		return PTR_ERR(td->soc_clk);
+	}
+
+	td->i2c_clk = devm_clk_get(td->dev, "i2c");
+	if (IS_ERR(td->i2c_clk)) {
+		dev_err(td->dev, "missing i2c clock\n");
+		return PTR_ERR(td->i2c_clk);
+	}
+	td->i2c_clk_rate = clk_get_rate(td->i2c_clk);
+
+	return 0;
+}
+
+/**
+ * dfll_init - Prepare the DFLL IP block for use
+ * @td: DFLL instance
+ *
+ * Do everything necessary to prepare the DFLL IP block for use. The
+ * DFLL will be left in DISABLED state. Called by dfll_probe().
+ * Returns 0 upon success, or passes along the error from whatever
+ * function returned it.
+ */
+static int dfll_init(struct tegra_dfll *td)
+{
+	int ret;
+
+	td->ref_rate = clk_get_rate(td->ref_clk);
+	if (td->ref_rate != REF_CLOCK_RATE) {
+		dev_err(td->dev, "unexpected ref clk rate %lu, expecting %lu",
+			td->ref_rate, REF_CLOCK_RATE);
+		return -EINVAL;
+	}
+
+	reset_control_deassert(td->dvco_rst);
+
+	ret = clk_prepare(td->ref_clk);
+	if (ret) {
+		dev_err(td->dev, "failed to prepare ref_clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare(td->soc_clk);
+	if (ret) {
+		dev_err(td->dev, "failed to prepare soc_clk\n");
+		goto di_err1;
+	}
+
+	ret = clk_prepare(td->i2c_clk);
+	if (ret) {
+		dev_err(td->dev, "failed to prepare i2c_clk\n");
+		goto di_err2;
+	}
+
+	td->last_unrounded_rate = 0;
+
+	pm_runtime_enable(td->dev);
+	pm_runtime_get_sync(td->dev);
+
+	dfll_set_mode(td, DFLL_DISABLED);
+	dfll_set_default_params(td);
+
+	if (td->soc->init_clock_trimmers)
+		td->soc->init_clock_trimmers();
+
+	dfll_set_open_loop_config(td);
+
+	dfll_init_out_if(td);
+
+	pm_runtime_put_sync(td->dev);
+
+	return 0;
+
+di_err2:
+	clk_unprepare(td->soc_clk);
+di_err1:
+	clk_unprepare(td->ref_clk);
+
+	reset_control_assert(td->dvco_rst);
+
+	return ret;
+}
+
+/*
+ * DT data fetch
+ */
+
+/*
+ * Find a PMIC voltage register-to-voltage mapping for the given voltage.
+ * An exact voltage match is required.
+ */
+static int find_vdd_map_entry_exact(struct tegra_dfll *td, int uV)
+{
+	int i, n_voltages, reg_uV;
+
+	n_voltages = regulator_count_voltages(td->vdd_reg);
+	for (i = 0; i < n_voltages; i++) {
+		reg_uV = regulator_list_voltage(td->vdd_reg, i);
+		if (reg_uV < 0)
+			break;
+
+		if (uV == reg_uV)
+			return i;
+	}
+
+	dev_err(td->dev, "no voltage map entry for %d uV\n", uV);
+	return -EINVAL;
+}
+
+/*
+ * Find a PMIC voltage register-to-voltage mapping for the given voltage,
+ * rounding up to the closest supported voltage.
+ * */
+static int find_vdd_map_entry_min(struct tegra_dfll *td, int uV)
+{
+	int i, n_voltages, reg_uV;
+
+	n_voltages = regulator_count_voltages(td->vdd_reg);
+	for (i = 0; i < n_voltages; i++) {
+		reg_uV = regulator_list_voltage(td->vdd_reg, i);
+		if (reg_uV < 0)
+			break;
+
+		if (uV <= reg_uV)
+			return i;
+	}
+
+	dev_err(td->dev, "no voltage map entry rounding to %d uV\n", uV);
+	return -EINVAL;
+}
+
+/**
+ * dfll_build_i2c_lut - build the I2C voltage register lookup table
+ * @td: DFLL instance
+ *
+ * The DFLL hardware has 33 bytes of look-up table RAM that must be filled with
+ * PMIC voltage register values that span the entire DFLL operating range.
+ * This function builds the look-up table based on the OPP table provided by
+ * the soc-specific platform driver (td->soc->opp_dev) and the PMIC
+ * register-to-voltage mapping queried from the regulator framework.
+ *
+ * On success, fills in td->i2c_lut and returns 0, or -err on failure.
+ */
+static int dfll_build_i2c_lut(struct tegra_dfll *td)
+{
+	int ret = -EINVAL;
+	int j, v, v_max, v_opp;
+	int selector;
+	unsigned long rate;
+	struct dev_pm_opp *opp;
+
+	rcu_read_lock();
+
+	rate = ULONG_MAX;
+	opp = dev_pm_opp_find_freq_floor(td->soc->dev, &rate);
+	if (IS_ERR(opp)) {
+		dev_err(td->dev, "couldn't get vmax opp, empty opp table?\n");
+		goto out;
+	}
+	v_max = dev_pm_opp_get_voltage(opp);
+
+	v = td->soc->min_millivolts * 1000;
+	td->i2c_lut[0] = find_vdd_map_entry_exact(td, v);
+	if (td->i2c_lut[0] < 0)
+		goto out;
+
+	for (j = 1, rate = 0; ; rate++) {
+		opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
+		if (IS_ERR(opp))
+			break;
+		v_opp = dev_pm_opp_get_voltage(opp);
+
+		if (v_opp <= td->soc->min_millivolts * 1000)
+			td->dvco_rate_min = dev_pm_opp_get_freq(opp);
+
+		for (;;) {
+			v += max(1, (v_max - v) / (MAX_DFLL_VOLTAGES - j));
+			if (v >= v_opp)
+				break;
+
+			selector = find_vdd_map_entry_min(td, v);
+			if (selector < 0)
+				goto out;
+			if (selector != td->i2c_lut[j - 1])
+				td->i2c_lut[j++] = selector;
+		}
+
+		v = (j == MAX_DFLL_VOLTAGES - 1) ? v_max : v_opp;
+		selector = find_vdd_map_entry_exact(td, v);
+		if (selector < 0)
+			goto out;
+		if (selector != td->i2c_lut[j - 1])
+			td->i2c_lut[j++] = selector;
+
+		if (v >= v_max)
+			break;
+	}
+	td->i2c_lut_size = j;
+
+	if (!td->dvco_rate_min)
+		dev_err(td->dev, "no opp above DFLL minimum voltage %d mV\n",
+			td->soc->min_millivolts);
+	else
+		ret = 0;
+
+out:
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/**
+ * read_dt_param - helper function for reading required parameters from the DT
+ * @td: DFLL instance
+ * @param: DT property name
+ * @dest: output pointer for the value read
+ *
+ * Read a required numeric parameter from the DFLL device node, or complain
+ * if the property doesn't exist. Returns a boolean indicating success for
+ * easy chaining of multiple calls to this function.
+ */
+static bool read_dt_param(struct tegra_dfll *td, const char *param, u32 *dest)
+{
+	int err = of_property_read_u32(td->dev->of_node, param, dest);
+
+	if (err < 0) {
+		dev_err(td->dev, "failed to read DT parameter %s: %d\n",
+			param, err);
+		return false;
+	}
+
+	return true;
+}
+
+/**
+ * dfll_fetch_i2c_params - query PMIC I2C params from DT & regulator subsystem
+ * @td: DFLL instance
+ *
+ * Read all the parameters required for operation in I2C mode. The parameters
+ * can originate from the device tree or the regulator subsystem.
+ * Returns 0 on success or -err on failure.
+ */
+static int dfll_fetch_i2c_params(struct tegra_dfll *td)
+{
+	struct regmap *regmap;
+	struct device *i2c_dev;
+	struct i2c_client *i2c_client;
+	int vsel_reg, vsel_mask;
+	int ret;
+
+	if (!read_dt_param(td, "nvidia,i2c-fs-rate", &td->i2c_fs_rate))
+		return -EINVAL;
+
+	regmap = regulator_get_regmap(td->vdd_reg);
+	i2c_dev = regmap_get_device(regmap);
+	i2c_client = to_i2c_client(i2c_dev);
+
+	td->i2c_slave_addr = i2c_client->addr;
+
+	ret = regulator_get_hardware_vsel_register(td->vdd_reg,
+						   &vsel_reg,
+						   &vsel_mask);
+	if (ret < 0) {
+		dev_err(td->dev,
+			"regulator unsuitable for DFLL I2C operation\n");
+		return -EINVAL;
+	}
+	td->i2c_reg = vsel_reg;
+
+	ret = dfll_build_i2c_lut(td);
+	if (ret) {
+		dev_err(td->dev, "couldn't build I2C LUT\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * dfll_fetch_common_params - read DFLL parameters from the device tree
+ * @td: DFLL instance
+ *
+ * Read all the DT parameters that are common to both I2C and PWM operation.
+ * Returns 0 on success or -EINVAL on any failure.
+ */
+static int dfll_fetch_common_params(struct tegra_dfll *td)
+{
+	bool ok = true;
+
+	ok &= read_dt_param(td, "nvidia,droop-ctrl", &td->droop_ctrl);
+	ok &= read_dt_param(td, "nvidia,sample-rate", &td->sample_rate);
+	ok &= read_dt_param(td, "nvidia,force-mode", &td->force_mode);
+	ok &= read_dt_param(td, "nvidia,cf", &td->cf);
+	ok &= read_dt_param(td, "nvidia,ci", &td->ci);
+	ok &= read_dt_param(td, "nvidia,cg", &td->cg);
+	td->cg_scale = of_property_read_bool(td->dev->of_node,
+					     "nvidia,cg-scale");
+
+	if (of_property_read_string(td->dev->of_node, "clock-output-names",
+				    &td->output_clock_name)) {
+		dev_err(td->dev, "missing clock-output-names property\n");
+		ok = false;
+	}
+
+	return ok ? 0 : -EINVAL;
+}
+
+/*
+ * API exported to per-SoC platform drivers
+ */
+
+/**
+ * tegra_dfll_register - probe a Tegra DFLL device
+ * @pdev: DFLL platform_device *
+ * @soc: Per-SoC integration and characterization data for this DFLL instance
+ *
+ * Probe and initialize a DFLL device instance. Intended to be called
+ * by a SoC-specific shim driver that passes in per-SoC integration
+ * and configuration data via @soc. Returns 0 on success or -err on failure.
+ */
+int tegra_dfll_register(struct platform_device *pdev,
+			struct tegra_dfll_soc_data *soc)
+{
+	struct resource *mem;
+	struct tegra_dfll *td;
+	int ret;
+
+	if (!soc) {
+		dev_err(&pdev->dev, "no tegra_dfll_soc_data provided\n");
+		return -EINVAL;
+	}
+
+	td = devm_kzalloc(&pdev->dev, sizeof(*td), GFP_KERNEL);
+	if (!td)
+		return -ENOMEM;
+	td->dev = &pdev->dev;
+	platform_set_drvdata(pdev, td);
+
+	td->soc = soc;
+
+	td->vdd_reg = devm_regulator_get(td->dev, "vdd-cpu");
+	if (IS_ERR(td->vdd_reg)) {
+		dev_err(td->dev, "couldn't get vdd_cpu regulator\n");
+		return PTR_ERR(td->vdd_reg);
+	}
+
+	td->dvco_rst = devm_reset_control_get(td->dev, "dvco");
+	if (IS_ERR(td->dvco_rst)) {
+		dev_err(td->dev, "couldn't get dvco reset\n");
+		return PTR_ERR(td->dvco_rst);
+	}
+
+	ret = dfll_fetch_common_params(td);
+	if (ret) {
+		dev_err(td->dev, "couldn't parse device tree parameters\n");
+		return ret;
+	}
+
+	ret = dfll_fetch_i2c_params(td);
+	if (ret)
+		return ret;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(td->dev, "no control register resource\n");
+		return -ENODEV;
+	}
+
+	td->base = devm_ioremap(td->dev, mem->start, resource_size(mem));
+	if (!td->base) {
+		dev_err(td->dev, "couldn't ioremap DFLL control registers\n");
+		return -ENODEV;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!mem) {
+		dev_err(td->dev, "no i2c_base resource\n");
+		return -ENODEV;
+	}
+
+	td->i2c_base = devm_ioremap(td->dev, mem->start, resource_size(mem));
+	if (!td->i2c_base) {
+		dev_err(td->dev, "couldn't ioremap i2c_base resource\n");
+		return -ENODEV;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (!mem) {
+		dev_err(td->dev, "no i2c_controller_base resource\n");
+		return -ENODEV;
+	}
+
+	td->i2c_controller_base = devm_ioremap(td->dev, mem->start,
+					       resource_size(mem));
+	if (!td->i2c_controller_base) {
+		dev_err(td->dev,
+			"couldn't ioremap i2c_controller_base resource\n");
+		return -ENODEV;
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 3);
+	if (!mem) {
+		dev_err(td->dev, "no lut_base resource\n");
+		return -ENODEV;
+	}
+
+	td->lut_base = devm_ioremap(td->dev, mem->start, resource_size(mem));
+	if (!td->lut_base) {
+		dev_err(td->dev,
+			"couldn't ioremap lut_base resource\n");
+		return -ENODEV;
+	}
+
+	ret = dfll_init_clks(td);
+	if (ret) {
+		dev_err(&pdev->dev, "DFLL clock init error\n");
+		return ret;
+	}
+
+	/* Enable the clocks and set the device up */
+	ret = dfll_init(td);
+	if (ret)
+		return ret;
+
+	ret = dfll_register_clk(td);
+	if (ret) {
+		dev_err(&pdev->dev, "DFLL clk registration failed\n");
+		return ret;
+	}
+
+#ifdef CONFIG_DEBUG_FS
+	dfll_debug_init(td);
+#endif
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_dfll_register);
+
+/**
+ * tegra_dfll_unregister - release all of the DFLL driver resources for a device
+ * @pdev: DFLL platform_device *
+ *
+ * Unbind this driver from the DFLL hardware device represented by
+ * @pdev. The DFLL must be disabled for this to succeed. Returns 0
+ * upon success or -EBUSY if the DFLL is still active.
+ */
+int tegra_dfll_unregister(struct platform_device *pdev)
+{
+	struct tegra_dfll *td = platform_get_drvdata(pdev);
+
+	/* Try to prevent removal while the DFLL is active */
+	if (td->mode != DFLL_DISABLED) {
+		dev_err(&pdev->dev,
+			"must disable DFLL before removing driver\n");
+		return -EBUSY;
+	}
+
+	debugfs_remove_recursive(td->debugfs_dir);
+
+	dfll_unregister_clk(td);
+	pm_runtime_disable(&pdev->dev);
+
+	clk_unprepare(td->ref_clk);
+	clk_unprepare(td->soc_clk);
+	clk_unprepare(td->i2c_clk);
+
+	reset_control_assert(td->dvco_rst);
+
+	return 0;
+}
+EXPORT_SYMBOL(tegra_dfll_unregister);
diff --git a/drivers/clk/tegra/clk-dfll.h b/drivers/clk/tegra/clk-dfll.h
new file mode 100644
index 000000000000..2e4c0772a5dc
--- /dev/null
+++ b/drivers/clk/tegra/clk-dfll.h
@@ -0,0 +1,54 @@
+/*
+ * clk-dfll.h - prototypes and macros for the Tegra DFLL clocksource driver
+ * Copyright (C) 2013 NVIDIA Corporation.  All rights reserved.
+ *
+ * Aleksandr Frid <afrid@nvidia.com>
+ * Paul Walmsley <pwalmsley@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#ifndef __DRIVERS_CLK_TEGRA_CLK_DFLL_H
+#define __DRIVERS_CLK_TEGRA_CLK_DFLL_H
+
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+/**
+ * struct tegra_dfll_soc_data - SoC-specific hooks/integration for the DFLL driver
+ * @opp_dev: struct device * that holds the OPP table for the DFLL
+ * @min_millivolts: minimum voltage (in mV) that the DFLL can operate
+ * @tune0_low: DFLL tuning register 0 (low voltage range)
+ * @tune0_high: DFLL tuning register 0 (high voltage range)
+ * @tune1: DFLL tuning register 1
+ * @assert_dvco_reset: fn ptr to place the DVCO in reset
+ * @deassert_dvco_reset: fn ptr to release the DVCO reset
+ * @set_clock_trimmers_high: fn ptr to tune clock trimmers for high voltage
+ * @set_clock_trimmers_low: fn ptr to tune clock trimmers for low voltage
+ */
+struct tegra_dfll_soc_data {
+	struct device *dev;
+	unsigned int min_millivolts;
+	u32 tune0_low;
+	u32 tune0_high;
+	u32 tune1;
+	void (*init_clock_trimmers)(void);
+	void (*set_clock_trimmers_high)(void);
+	void (*set_clock_trimmers_low)(void);
+};
+
+int tegra_dfll_register(struct platform_device *pdev,
+			struct tegra_dfll_soc_data *soc);
+int tegra_dfll_unregister(struct platform_device *pdev);
+int tegra_dfll_runtime_suspend(struct device *dev);
+int tegra_dfll_runtime_resume(struct device *dev);
+
+#endif /* __DRIVERS_CLK_TEGRA_CLK_DFLL_H */
diff --git a/drivers/clk/tegra/clk-tegra-super-gen4.c b/drivers/clk/tegra/clk-tegra-super-gen4.c
index feb3201c85ce..f1f441034b86 100644
--- a/drivers/clk/tegra/clk-tegra-super-gen4.c
+++ b/drivers/clk/tegra/clk-tegra-super-gen4.c
@@ -44,7 +44,9 @@ static const char *sclk_parents[] = { "clk_m", "pll_c_out1", "pll_p_out4",
 
 static const char *cclk_g_parents[] = { "clk_m", "pll_c", "clk_32k", "pll_m",
 					"pll_p", "pll_p_out4", "unused",
-					"unused", "pll_x" };
+					"unused", "pll_x", "unused", "unused",
+					"unused", "unused", "unused", "unused",
+					"dfllCPU_out" };
 
 static const char *cclk_lp_parents[] = { "clk_m", "pll_c", "clk_32k", "pll_m",
 					 "pll_p", "pll_p_out4", "unused",
diff --git a/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
new file mode 100644
index 000000000000..61253330c12b
--- /dev/null
+++ b/drivers/clk/tegra/clk-tegra124-dfll-fcpu.c
@@ -0,0 +1,166 @@
+/*
+ * Tegra124 DFLL FCPU clock source driver
+ *
+ * Copyright (C) 2012-2014 NVIDIA Corporation.  All rights reserved.
+ *
+ * Aleksandr Frid <afrid@nvidia.com>
+ * Paul Walmsley <pwalmsley@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <soc/tegra/fuse.h>
+
+#include "clk.h"
+#include "clk-dfll.h"
+#include "cvb.h"
+
+/* Maximum CPU frequency, indexed by CPU speedo id */
+static const unsigned long cpu_max_freq_table[] = {
+	[0] = 2014500000UL,
+	[1] = 2320500000UL,
+	[2] = 2116500000UL,
+	[3] = 2524500000UL,
+};
+
+static const struct cvb_table tegra124_cpu_cvb_tables[] = {
+	{
+		.speedo_id = -1,
+		.process_id = -1,
+		.min_millivolts = 900,
+		.max_millivolts = 1260,
+		.alignment = {
+			.step_uv = 10000, /* 10mV */
+		},
+		.speedo_scale = 100,
+		.voltage_scale = 1000,
+		.cvb_table = {
+			{204000000UL,   {1112619, -29295, 402} },
+			{306000000UL,	{1150460, -30585, 402} },
+			{408000000UL,	{1190122, -31865, 402} },
+			{510000000UL,	{1231606, -33155, 402} },
+			{612000000UL,	{1274912, -34435, 402} },
+			{714000000UL,	{1320040, -35725, 402} },
+			{816000000UL,	{1366990, -37005, 402} },
+			{918000000UL,	{1415762, -38295, 402} },
+			{1020000000UL,	{1466355, -39575, 402} },
+			{1122000000UL,	{1518771, -40865, 402} },
+			{1224000000UL,	{1573009, -42145, 402} },
+			{1326000000UL,	{1629068, -43435, 402} },
+			{1428000000UL,	{1686950, -44715, 402} },
+			{1530000000UL,	{1746653, -46005, 402} },
+			{1632000000UL,	{1808179, -47285, 402} },
+			{1734000000UL,	{1871526, -48575, 402} },
+			{1836000000UL,	{1936696, -49855, 402} },
+			{1938000000UL,	{2003687, -51145, 402} },
+			{2014500000UL,	{2054787, -52095, 402} },
+			{2116500000UL,	{2124957, -53385, 402} },
+			{2218500000UL,	{2196950, -54665, 402} },
+			{2320500000UL,	{2270765, -55955, 402} },
+			{2422500000UL,	{2346401, -57235, 402} },
+			{2524500000UL,	{2437299, -58535, 402} },
+			{0,		{      0,      0,   0} },
+		},
+		.cpu_dfll_data = {
+			.tune0_low = 0x005020ff,
+			.tune0_high = 0x005040ff,
+			.tune1 = 0x00000060,
+		}
+	},
+};
+
+static int tegra124_dfll_fcpu_probe(struct platform_device *pdev)
+{
+	int process_id, speedo_id, speedo_value;
+	struct tegra_dfll_soc_data *soc;
+	const struct cvb_table *cvb;
+
+	process_id = tegra_sku_info.cpu_process_id;
+	speedo_id = tegra_sku_info.cpu_speedo_id;
+	speedo_value = tegra_sku_info.cpu_speedo_value;
+
+	if (speedo_id >= ARRAY_SIZE(cpu_max_freq_table)) {
+		dev_err(&pdev->dev, "unknown max CPU freq for speedo_id=%d\n",
+			speedo_id);
+		return -ENODEV;
+	}
+
+	soc = devm_kzalloc(&pdev->dev, sizeof(*soc), GFP_KERNEL);
+	if (!soc)
+		return -ENOMEM;
+
+	soc->dev = get_cpu_device(0);
+	if (!soc->dev) {
+		dev_err(&pdev->dev, "no CPU0 device\n");
+		return -ENODEV;
+	}
+
+	cvb = tegra_cvb_build_opp_table(tegra124_cpu_cvb_tables,
+					ARRAY_SIZE(tegra124_cpu_cvb_tables),
+					process_id, speedo_id, speedo_value,
+					cpu_max_freq_table[speedo_id],
+					soc->dev);
+	if (IS_ERR(cvb)) {
+		dev_err(&pdev->dev, "couldn't build OPP table: %ld\n",
+			PTR_ERR(cvb));
+		return PTR_ERR(cvb);
+	}
+
+	soc->min_millivolts = cvb->min_millivolts;
+	soc->tune0_low = cvb->cpu_dfll_data.tune0_low;
+	soc->tune0_high = cvb->cpu_dfll_data.tune0_high;
+	soc->tune1 = cvb->cpu_dfll_data.tune1;
+
+	return tegra_dfll_register(pdev, soc);
+}
+
+static const struct of_device_id tegra124_dfll_fcpu_of_match[] = {
+	{ .compatible = "nvidia,tegra124-dfll", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra124_dfll_fcpu_of_match);
+
+static const struct dev_pm_ops tegra124_dfll_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra_dfll_runtime_suspend,
+			   tegra_dfll_runtime_resume, NULL)
+};
+
+static struct platform_driver tegra124_dfll_fcpu_driver = {
+	.probe = tegra124_dfll_fcpu_probe,
+	.remove = tegra_dfll_unregister,
+	.driver = {
+		.name = "tegra124-dfll",
+		.of_match_table = tegra124_dfll_fcpu_of_match,
+		.pm = &tegra124_dfll_pm_ops,
+	},
+};
+
+static int __init tegra124_dfll_fcpu_init(void)
+{
+	return platform_driver_register(&tegra124_dfll_fcpu_driver);
+}
+module_init(tegra124_dfll_fcpu_init);
+
+static void __exit tegra124_dfll_fcpu_exit(void)
+{
+	platform_driver_unregister(&tegra124_dfll_fcpu_driver);
+}
+module_exit(tegra124_dfll_fcpu_exit);
+
+MODULE_DESCRIPTION("Tegra124 DFLL clock source driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Aleksandr Frid <afrid@nvidia.com>");
+MODULE_AUTHOR("Paul Walmsley <pwalmsley@nvidia.com>");
diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c
index e8cca3eac007..a4886741e293 100644
--- a/drivers/clk/tegra/clk-tegra124.c
+++ b/drivers/clk/tegra/clk-tegra124.c
@@ -24,6 +24,7 @@
 #include <linux/export.h>
 #include <linux/clk/tegra.h>
 #include <dt-bindings/clock/tegra124-car.h>
+#include <dt-bindings/reset/tegra124-car.h>
 
 #include "clk.h"
 #include "clk-id.h"
@@ -39,6 +40,9 @@
 #define CLK_SOURCE_CSITE 0x1d4
 #define CLK_SOURCE_EMC 0x19c
 
+#define RST_DFLL_DVCO			0x2f4
+#define DVFS_DFLL_RESET_SHIFT		0
+
 #define PLLC_BASE 0x80
 #define PLLC_OUT 0x84
 #define PLLC_MISC2 0x88
@@ -94,6 +98,8 @@
 #define PMC_PLLM_WB0_OVERRIDE 0x1dc
 #define PMC_PLLM_WB0_OVERRIDE_2 0x2b0
 
+#define CCLKG_BURST_POLICY 0x368
+
 #define UTMIP_PLL_CFG2 0x488
 #define UTMIP_PLL_CFG2_STABLE_COUNT(x) (((x) & 0xffff) << 6)
 #define UTMIP_PLL_CFG2_ACTIVE_DLY_COUNT(x) (((x) & 0x3f) << 18)
@@ -126,6 +132,8 @@
 #ifdef CONFIG_PM_SLEEP
 static struct cpu_clk_suspend_context {
 	u32 clk_csite_src;
+	u32 cclkg_burst;
+	u32 cclkg_divider;
 } tegra124_cpu_clk_sctx;
 #endif
 
@@ -1319,12 +1327,22 @@ static void tegra124_cpu_clock_suspend(void)
 	tegra124_cpu_clk_sctx.clk_csite_src =
 				readl(clk_base + CLK_SOURCE_CSITE);
 	writel(3 << 30, clk_base + CLK_SOURCE_CSITE);
+
+	tegra124_cpu_clk_sctx.cclkg_burst =
+				readl(clk_base + CCLKG_BURST_POLICY);
+	tegra124_cpu_clk_sctx.cclkg_divider =
+				readl(clk_base + CCLKG_BURST_POLICY + 4);
 }
 
 static void tegra124_cpu_clock_resume(void)
 {
 	writel(tegra124_cpu_clk_sctx.clk_csite_src,
 				clk_base + CLK_SOURCE_CSITE);
+
+	writel(tegra124_cpu_clk_sctx.cclkg_burst,
+					clk_base + CCLKG_BURST_POLICY);
+	writel(tegra124_cpu_clk_sctx.cclkg_divider,
+					clk_base + CCLKG_BURST_POLICY + 4);
 }
 #endif
 
@@ -1415,6 +1433,68 @@ static void __init tegra124_clock_apply_init_table(void)
 }
 
 /**
+ * tegra124_car_barrier - wait for pending writes to the CAR to complete
+ *
+ * Wait for any outstanding writes to the CAR MMIO space from this CPU
+ * to complete before continuing execution.  No return value.
+ */
+static void tegra124_car_barrier(void)
+{
+	readl_relaxed(clk_base + RST_DFLL_DVCO);
+}
+
+/**
+ * tegra124_clock_assert_dfll_dvco_reset - assert the DFLL's DVCO reset
+ *
+ * Assert the reset line of the DFLL's DVCO.  No return value.
+ */
+void tegra124_clock_assert_dfll_dvco_reset(void)
+{
+	u32 v;
+
+	v = readl_relaxed(clk_base + RST_DFLL_DVCO);
+	v |= (1 << DVFS_DFLL_RESET_SHIFT);
+	writel_relaxed(v, clk_base + RST_DFLL_DVCO);
+	tegra124_car_barrier();
+}
+
+/**
+ * tegra124_clock_deassert_dfll_dvco_reset - deassert the DFLL's DVCO reset
+ *
+ * Deassert the reset line of the DFLL's DVCO, allowing the DVCO to
+ * operate.  No return value.
+ */
+void tegra124_clock_deassert_dfll_dvco_reset(void)
+{
+	u32 v;
+
+	v = readl_relaxed(clk_base + RST_DFLL_DVCO);
+	v &= ~(1 << DVFS_DFLL_RESET_SHIFT);
+	writel_relaxed(v, clk_base + RST_DFLL_DVCO);
+	tegra124_car_barrier();
+}
+
+int tegra124_reset_assert(unsigned long id)
+{
+	if (id == TEGRA124_RST_DFLL_DVCO)
+		tegra124_clock_assert_dfll_dvco_reset();
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+int tegra124_reset_deassert(unsigned long id)
+{
+	if (id == TEGRA124_RST_DFLL_DVCO)
+		tegra124_clock_deassert_dfll_dvco_reset();
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
  * tegra132_clock_apply_init_table - initialize clocks on Tegra132 SoCs
  *
  * Program an initial clock rate and enable or disable clocks needed
@@ -1499,6 +1579,8 @@ static void __init tegra124_132_clock_init_post(struct device_node *np)
 {
 	tegra_super_clk_gen4_init(clk_base, pmc_base, tegra124_clks,
 				  &pll_x_params);
+	tegra_init_special_resets(1, tegra124_reset_assert,
+				  tegra124_reset_deassert);
 	tegra_add_of_provider(np);
 
 	clks[TEGRA124_CLK_EMC] = tegra_clk_register_emc(clk_base, np,
diff --git a/drivers/clk/tegra/clk.c b/drivers/clk/tegra/clk.c
index 41cd87c67be6..3290fd648d1e 100644
--- a/drivers/clk/tegra/clk.c
+++ b/drivers/clk/tegra/clk.c
@@ -49,7 +49,6 @@
 #define RST_DEVICES_L			0x004
 #define RST_DEVICES_H			0x008
 #define RST_DEVICES_U			0x00C
-#define RST_DFLL_DVCO			0x2F4
 #define RST_DEVICES_V			0x358
 #define RST_DEVICES_W			0x35C
 #define RST_DEVICES_X			0x28C
@@ -79,6 +78,11 @@ static struct clk **clks;
 static int clk_num;
 static struct clk_onecell_data clk_data;
 
+/* Handlers for SoC-specific reset lines */
+static int (*special_reset_assert)(unsigned long);
+static int (*special_reset_deassert)(unsigned long);
+static unsigned int num_special_reset;
+
 static struct tegra_clk_periph_regs periph_regs[] = {
 	[0] = {
 		.enb_reg = CLK_OUT_ENB_L,
@@ -152,19 +156,29 @@ static int tegra_clk_rst_assert(struct reset_controller_dev *rcdev,
 	 */
 	tegra_read_chipid();
 
-	writel_relaxed(BIT(id % 32),
-			clk_base + periph_regs[id / 32].rst_set_reg);
+	if (id < periph_banks * 32) {
+		writel_relaxed(BIT(id % 32),
+			       clk_base + periph_regs[id / 32].rst_set_reg);
+		return 0;
+	} else if (id < periph_banks * 32 + num_special_reset) {
+		return special_reset_assert(id);
+	}
 
-	return 0;
+	return -EINVAL;
 }
 
 static int tegra_clk_rst_deassert(struct reset_controller_dev *rcdev,
 		unsigned long id)
 {
-	writel_relaxed(BIT(id % 32),
-			clk_base + periph_regs[id / 32].rst_clr_reg);
+	if (id < periph_banks * 32) {
+		writel_relaxed(BIT(id % 32),
+			       clk_base + periph_regs[id / 32].rst_clr_reg);
+		return 0;
+	} else if (id < periph_banks * 32 + num_special_reset) {
+		return special_reset_deassert(id);
+	}
 
-	return 0;
+	return -EINVAL;
 }
 
 struct tegra_clk_periph_regs *get_reg_bank(int clkid)
@@ -286,10 +300,19 @@ void __init tegra_add_of_provider(struct device_node *np)
 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
 
 	rst_ctlr.of_node = np;
-	rst_ctlr.nr_resets = periph_banks * 32;
+	rst_ctlr.nr_resets = periph_banks * 32 + num_special_reset;
 	reset_controller_register(&rst_ctlr);
 }
 
+void __init tegra_init_special_resets(unsigned int num,
+				      int (*assert)(unsigned long),
+				      int (*deassert)(unsigned long))
+{
+	num_special_reset = num;
+	special_reset_assert = assert;
+	special_reset_deassert = deassert;
+}
+
 void __init tegra_register_devclks(struct tegra_devclk *dev_clks, int num)
 {
 	int i;
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index 75ddc8ff8bd4..0621887e06f7 100644
--- a/drivers/clk/tegra/clk.h
+++ b/drivers/clk/tegra/clk.h
@@ -591,6 +591,9 @@ struct tegra_devclk {
 	char		*con_id;
 };
 
+void tegra_init_special_resets(unsigned int num, int (*assert)(unsigned long),
+			       int (*deassert)(unsigned long));
+
 void tegra_init_from_table(struct tegra_clk_init_table *tbl,
 		struct clk *clks[], int clk_max);
 
diff --git a/drivers/clk/tegra/cvb.c b/drivers/clk/tegra/cvb.c
new file mode 100644
index 000000000000..0204e0861134
--- /dev/null
+++ b/drivers/clk/tegra/cvb.c
@@ -0,0 +1,140 @@
+/*
+ * Utility functions for parsing Tegra CVB voltage tables
+ *
+ * Copyright (C) 2012-2014 NVIDIA Corporation.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/pm_opp.h>
+
+#include "cvb.h"
+
+/* cvb_mv = ((c2 * speedo / s_scale + c1) * speedo / s_scale + c0) */
+static inline int get_cvb_voltage(int speedo, int s_scale,
+				  const struct cvb_coefficients *cvb)
+{
+	int mv;
+
+	/* apply only speedo scale: output mv = cvb_mv * v_scale */
+	mv = DIV_ROUND_CLOSEST(cvb->c2 * speedo, s_scale);
+	mv = DIV_ROUND_CLOSEST((mv + cvb->c1) * speedo, s_scale) + cvb->c0;
+	return mv;
+}
+
+static int round_cvb_voltage(int mv, int v_scale,
+			     const struct rail_alignment *align)
+{
+	/* combined: apply voltage scale and round to cvb alignment step */
+	int uv;
+	int step = (align->step_uv ? : 1000) * v_scale;
+	int offset = align->offset_uv * v_scale;
+
+	uv = max(mv * 1000, offset) - offset;
+	uv = DIV_ROUND_UP(uv, step) * align->step_uv + align->offset_uv;
+	return uv / 1000;
+}
+
+enum {
+	DOWN,
+	UP
+};
+
+static int round_voltage(int mv, const struct rail_alignment *align, int up)
+{
+	if (align->step_uv) {
+		int uv;
+
+		uv = max(mv * 1000, align->offset_uv) - align->offset_uv;
+		uv = (uv + (up ? align->step_uv - 1 : 0)) / align->step_uv;
+		return (uv * align->step_uv + align->offset_uv) / 1000;
+	}
+	return mv;
+}
+
+static int build_opp_table(const struct cvb_table *d,
+			   int speedo_value,
+			   unsigned long max_freq,
+			   struct device *opp_dev)
+{
+	int i, ret, dfll_mv, min_mv, max_mv;
+	const struct cvb_table_freq_entry *table = NULL;
+	const struct rail_alignment *align = &d->alignment;
+
+	min_mv = round_voltage(d->min_millivolts, align, UP);
+	max_mv = round_voltage(d->max_millivolts, align, DOWN);
+
+	for (i = 0; i < MAX_DVFS_FREQS; i++) {
+		table = &d->cvb_table[i];
+		if (!table->freq || (table->freq > max_freq))
+			break;
+
+		/*
+		 * FIXME after clk_round_rate/clk_determine_rate prototypes
+		 * have been updated
+		 */
+		if (table->freq & (1<<31))
+			continue;
+
+		dfll_mv = get_cvb_voltage(
+			speedo_value, d->speedo_scale, &table->coefficients);
+		dfll_mv = round_cvb_voltage(dfll_mv, d->voltage_scale, align);
+		dfll_mv = clamp(dfll_mv, min_mv, max_mv);
+
+		ret = dev_pm_opp_add(opp_dev, table->freq, dfll_mv * 1000);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * tegra_cvb_build_opp_table - build OPP table from Tegra CVB tables
+ * @cvb_tables: array of CVB tables
+ * @sz: size of the previously mentioned array
+ * @process_id: process id of the HW module
+ * @speedo_id: speedo id of the HW module
+ * @speedo_value: speedo value of the HW module
+ * @max_rate: highest safe clock rate
+ * @opp_dev: the struct device * for which the OPP table is built
+ *
+ * On Tegra, a CVB table encodes the relationship between operating voltage
+ * and safe maximal frequency for a given module (e.g. GPU or CPU). This
+ * function calculates the optimal voltage-frequency operating points
+ * for the given arguments and exports them via the OPP library for the
+ * given @opp_dev. Returns a pointer to the struct cvb_table that matched
+ * or an ERR_PTR on failure.
+ */
+const struct cvb_table *tegra_cvb_build_opp_table(
+		const struct cvb_table *cvb_tables,
+		size_t sz, int process_id,
+		int speedo_id, int speedo_value,
+		unsigned long max_rate,
+		struct device *opp_dev)
+{
+	int i, ret;
+
+	for (i = 0; i < sz; i++) {
+		const struct cvb_table *d = &cvb_tables[i];
+
+		if (d->speedo_id != -1 && d->speedo_id != speedo_id)
+			continue;
+		if (d->process_id != -1 && d->process_id != process_id)
+			continue;
+
+		ret = build_opp_table(d, speedo_value, max_rate, opp_dev);
+		return ret ? ERR_PTR(ret) : d;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
diff --git a/drivers/clk/tegra/cvb.h b/drivers/clk/tegra/cvb.h
new file mode 100644
index 000000000000..f62cdc4f4234
--- /dev/null
+++ b/drivers/clk/tegra/cvb.h
@@ -0,0 +1,67 @@
+/*
+ * Utility functions for parsing Tegra CVB voltage tables
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ */
+
+#ifndef __DRIVERS_CLK_TEGRA_CVB_H
+#define __DRIVERS_CLK_TEGRA_CVB_H
+
+#include <linux/types.h>
+
+struct device;
+
+#define MAX_DVFS_FREQS	40
+
+struct rail_alignment {
+	int offset_uv;
+	int step_uv;
+};
+
+struct cvb_coefficients {
+	int c0;
+	int c1;
+	int c2;
+};
+
+struct cvb_table_freq_entry {
+	unsigned long freq;
+	struct cvb_coefficients coefficients;
+};
+
+struct cvb_cpu_dfll_data {
+	u32 tune0_low;
+	u32 tune0_high;
+	u32 tune1;
+};
+
+struct cvb_table {
+	int speedo_id;
+	int process_id;
+
+	int min_millivolts;
+	int max_millivolts;
+	struct rail_alignment alignment;
+
+	int speedo_scale;
+	int voltage_scale;
+	struct cvb_table_freq_entry cvb_table[MAX_DVFS_FREQS];
+	struct cvb_cpu_dfll_data cpu_dfll_data;
+};
+
+const struct cvb_table *tegra_cvb_build_opp_table(
+		const struct cvb_table *cvb_tables,
+		size_t sz, int process_id,
+		int speedo_id, int speedo_value,
+		unsigned long max_rate,
+		struct device *opp_dev);
+
+#endif