--- /dev/null
+/*
+ * 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;
+}
+
+/*
+ * 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;
+
+ rcu_read_lock();
+
+ opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
+ if (IS_ERR(opp)) {
+ rcu_read_unlock();
+ return PTR_ERR(opp);
+ }
+ uv = dev_pm_opp_get_voltage(opp);
+
+ rcu_read_unlock();
+
+ 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;
+}
+
+/* Must use determine_rate since it allows for rates exceeding 2^31-1 */
+static int dfll_clk_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *clk_req)
+{
+ struct tegra_dfll *td = clk_hw_to_dfll(hw);
+ struct dfll_rate_req req;
+ int ret;
+
+ ret = dfll_calculate_rate_request(td, &req, clk_req->rate);
+ if (ret)
+ return ret;
+
+ /*
+ * Don't set 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 0;
+}
+
+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,
+ .determine_rate = dfll_clk_determine_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
+/*
+ * 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;
+}
+
+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;
+ int lut;
+
+ 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;
+ lut = find_vdd_map_entry_exact(td, v);
+ if (lut < 0)
+ goto out;
+ td->i2c_lut[0] = lut;
+
+ 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);
Code Review / kvmfornfv.git / blobdiff