// SPDX-License-Identifier: GPL-2.0-only /* * clk-dfll.c - Tegra DFLL clock source common code * * Copyright (C) 2012-2019 NVIDIA Corporation. All rights reserved. * * Aleksandr Frid * Paul Walmsley * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "clk-dfll.h" #include "cvb.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, }; enum tegra_dfll_pmu_if { TEGRA_DFLL_PMU_I2C = 0, TEGRA_DFLL_PMU_PWM = 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; /* lut array entries are regulator framework selectors or PWM values*/ unsigned lut[MAX_DFLL_VOLTAGES]; unsigned long lut_uv[MAX_DFLL_VOLTAGES]; int lut_size; u8 lut_bottom, lut_min, lut_max, lut_safe; /* PWM interface */ enum tegra_dfll_pmu_if pmu_if; unsigned long pwm_rate; struct pinctrl *pwm_pin; struct pinctrl_state *pwm_enable_state; struct pinctrl_state *pwm_disable_state; u32 reg_init_uV; }; #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->cvb->cpu_dfll_data.tune0_low, DFLL_TUNE0); dfll_writel(td, td->soc->cvb->cpu_dfll_data.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); } /* * DVCO rate control */ static unsigned long get_dvco_rate_below(struct tegra_dfll *td, u8 out_min) { struct dev_pm_opp *opp; unsigned long rate, prev_rate; unsigned long uv, min_uv; min_uv = td->lut_uv[out_min]; for (rate = 0, prev_rate = 0; ; rate++) { opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate); if (IS_ERR(opp)) break; uv = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); if (uv && uv > min_uv) return prev_rate; prev_rate = rate; } return prev_rate; } /* * 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-to-PWM controller interface */ /** * dfll_pwm_set_output_enabled - enable/disable PWM voltage requests * @td: DFLL instance * @enable: whether to enable or disable the PWM voltage requests * * Set the master enable control for PWM control value updates. If disabled, * then the PWM signal is not driven. Also configure the PWM output pad * to the appropriate state. */ static int dfll_pwm_set_output_enabled(struct tegra_dfll *td, bool enable) { int ret; u32 val, div; if (enable) { ret = pinctrl_select_state(td->pwm_pin, td->pwm_enable_state); if (ret < 0) { dev_err(td->dev, "setting enable state failed\n"); return -EINVAL; } val = dfll_readl(td, DFLL_OUTPUT_CFG); val &= ~DFLL_OUTPUT_CFG_PWM_DIV_MASK; div = DIV_ROUND_UP(td->ref_rate, td->pwm_rate); val |= (div << DFLL_OUTPUT_CFG_PWM_DIV_SHIFT) & DFLL_OUTPUT_CFG_PWM_DIV_MASK; dfll_writel(td, val, DFLL_OUTPUT_CFG); dfll_wmb(td); val |= DFLL_OUTPUT_CFG_PWM_ENABLE; dfll_writel(td, val, DFLL_OUTPUT_CFG); dfll_wmb(td); } else { ret = pinctrl_select_state(td->pwm_pin, td->pwm_disable_state); if (ret < 0) dev_warn(td->dev, "setting disable state failed\n"); val = dfll_readl(td, DFLL_OUTPUT_CFG); val &= ~DFLL_OUTPUT_CFG_PWM_ENABLE; dfll_writel(td, val, DFLL_OUTPUT_CFG); dfll_wmb(td); } return 0; } /** * dfll_set_force_output_value - set fixed value for force output * @td: DFLL instance * @out_val: value to force output * * Set the fixed value for force output, DFLL will output this value when * force output is enabled. */ static u32 dfll_set_force_output_value(struct tegra_dfll *td, u8 out_val) { u32 val = dfll_readl(td, DFLL_OUTPUT_FORCE); val = (val & DFLL_OUTPUT_FORCE_ENABLE) | (out_val & OUT_MASK); dfll_writel(td, val, DFLL_OUTPUT_FORCE); dfll_wmb(td); return dfll_readl(td, DFLL_OUTPUT_FORCE); } /** * dfll_set_force_output_enabled - enable/disable force output * @td: DFLL instance * @enable: whether to enable or disable the force output * * Set the enable control for fouce output with fixed value. */ static void dfll_set_force_output_enabled(struct tegra_dfll *td, bool enable) { u32 val = dfll_readl(td, DFLL_OUTPUT_FORCE); if (enable) val |= DFLL_OUTPUT_FORCE_ENABLE; else val &= ~DFLL_OUTPUT_FORCE_ENABLE; dfll_writel(td, val, DFLL_OUTPUT_FORCE); dfll_wmb(td); } /** * dfll_force_output - force output a fixed value * @td: DFLL instance * @out_sel: value to force output * * Set the fixed value for force output, DFLL will output this value. */ static int dfll_force_output(struct tegra_dfll *td, unsigned int out_sel) { u32 val; if (out_sel > OUT_MASK) return -EINVAL; val = dfll_set_force_output_value(td, out_sel); if ((td->mode < DFLL_CLOSED_LOOP) && !(val & DFLL_OUTPUT_FORCE_ENABLE)) { dfll_set_force_output_enabled(td, true); } 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->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 = td->lut_bottom; td->lut_max = td->lut_size - 1; td->lut_safe = td->lut_min + (td->lut_min < td->lut_max ? 1 : 0); /* clear DFLL_OUTPUT_CFG before setting new value */ dfll_writel(td, 0, DFLL_OUTPUT_CFG); dfll_wmb(td); 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_writel(td, val, DFLL_OUTPUT_CFG); dfll_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); if (td->pmu_if == TEGRA_DFLL_PMU_PWM) { u32 vinit = td->reg_init_uV; int vstep = td->soc->alignment.step_uv; unsigned long vmin = td->lut_uv[0]; /* set initial voltage */ if ((vinit >= vmin) && vstep) { unsigned int vsel; vsel = DIV_ROUND_UP((vinit - vmin), vstep); dfll_force_output(td, vsel); } } else { 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, align_step; opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate); if (IS_ERR(opp)) return PTR_ERR(opp); align_step = dev_pm_opp_get_voltage(opp) / td->soc->alignment.step_uv; dev_pm_opp_put(opp); for (i = td->lut_bottom; i < td->lut_size; i++) { if ((td->lut_uv[i] / td->soc->alignment.step_uv) >= align_step) 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; } if (td->pmu_if == TEGRA_DFLL_PMU_PWM) dfll_pwm_set_output_enabled(td, true); else dfll_i2c_set_output_enabled(td, true); dfll_set_mode(td, DFLL_CLOSED_LOOP); dfll_set_frequency_request(td, req); dfll_set_force_output_enabled(td, false); 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); if (td->pmu_if == TEGRA_DFLL_PMU_PWM) dfll_pwm_set_output_enabled(td, false); else 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 = { .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_DEBUGFS_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_DEBUGFS_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_DEBUGFS_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)); if (td->pmu_if == TEGRA_DFLL_PMU_I2C) { 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; } DEFINE_SHOW_ATTRIBUTE(attr_registers); static void dfll_debug_init(struct tegra_dfll *td) { struct dentry *root; if (!td || (td->mode == DFLL_UNINITIALIZED)) return; root = debugfs_create_dir("tegra_dfll_fcpu", NULL); td->debugfs_dir = root; debugfs_create_file_unsafe("enable", 0644, root, td, &enable_fops); debugfs_create_file_unsafe("lock", 0444, root, td, &lock_fops); debugfs_create_file_unsafe("rate", 0444, root, td, &rate_fops); debugfs_create_file("registers", 0444, root, td, &attr_registers_fops); } #else static void inline dfll_debug_init(struct tegra_dfll *td) { } #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_irq_safe(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; } /** * tegra_dfll_suspend - check DFLL is disabled * @dev: DFLL device * * * DFLL clock should be disabled by the CPUFreq driver. So, make * sure it is disabled and disable all clocks needed by the DFLL. */ int tegra_dfll_suspend(struct device *dev) { struct tegra_dfll *td = dev_get_drvdata(dev); if (dfll_is_running(td)) { dev_err(td->dev, "DFLL still enabled while suspending\n"); return -EBUSY; } reset_control_assert(td->dvco_rst); return 0; } EXPORT_SYMBOL(tegra_dfll_suspend); /** * tegra_dfll_resume - reinitialize DFLL on resume * @dev: DFLL instance * * DFLL is disabled and reset during suspend and resume. * So, reinitialize the DFLL IP block back for use. * DFLL clock is enabled later in closed loop mode by CPUFreq * driver before switching its clock source to DFLL output. */ int tegra_dfll_resume(struct device *dev) { struct tegra_dfll *td = dev_get_drvdata(dev); reset_control_deassert(td->dvco_rst); 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; } EXPORT_SYMBOL(tegra_dfll_resume); /* * 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,reg_volt_id, align_step; if (WARN_ON(td->pmu_if == TEGRA_DFLL_PMU_PWM)) return -EINVAL; align_step = uV / td->soc->alignment.step_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; reg_volt_id = reg_uV / td->soc->alignment.step_uv; if (align_step == reg_volt_id) 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, reg_volt_id, align_step; if (WARN_ON(td->pmu_if == TEGRA_DFLL_PMU_PWM)) return -EINVAL; align_step = uV / td->soc->alignment.step_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; reg_volt_id = reg_uV / td->soc->alignment.step_uv; if (align_step <= reg_volt_id) return i; } dev_err(td->dev, "no voltage map entry rounding to %d uV\n", uV); return -EINVAL; } /* * dfll_build_pwm_lut - build the PWM regulator lookup table * @td: DFLL instance * @v_max: Vmax from OPP table * * Look-up table in h/w is ignored when PWM is used as DFLL interface to PMIC. * In this case closed loop output is controlling duty cycle directly. The s/w * look-up that maps PWM duty cycle to voltage is still built by this function. */ static int dfll_build_pwm_lut(struct tegra_dfll *td, unsigned long v_max) { int i; unsigned long rate, reg_volt; u8 lut_bottom = MAX_DFLL_VOLTAGES; int v_min = td->soc->cvb->min_millivolts * 1000; for (i = 0; i < MAX_DFLL_VOLTAGES; i++) { reg_volt = td->lut_uv[i]; /* since opp voltage is exact mv */ reg_volt = (reg_volt / 1000) * 1000; if (reg_volt > v_max) break; td->lut[i] = i; if ((lut_bottom == MAX_DFLL_VOLTAGES) && (reg_volt >= v_min)) lut_bottom = i; } /* determine voltage boundaries */ td->lut_size = i; if ((lut_bottom == MAX_DFLL_VOLTAGES) || (lut_bottom + 1 >= td->lut_size)) { dev_err(td->dev, "no voltage above DFLL minimum %d mV\n", td->soc->cvb->min_millivolts); return -EINVAL; } td->lut_bottom = lut_bottom; /* determine rate boundaries */ rate = get_dvco_rate_below(td, td->lut_bottom); if (!rate) { dev_err(td->dev, "no opp below DFLL minimum voltage %d mV\n", td->soc->cvb->min_millivolts); return -EINVAL; } td->dvco_rate_min = rate; return 0; } /** * dfll_build_i2c_lut - build the I2C voltage register lookup table * @td: DFLL instance * @v_max: Vmax from OPP table * * 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->lut and returns 0, or -err on failure. */ static int dfll_build_i2c_lut(struct tegra_dfll *td, unsigned long v_max) { unsigned long rate, v, v_opp; int ret = -EINVAL; int j, selector, lut; v = td->soc->cvb->min_millivolts * 1000; lut = find_vdd_map_entry_exact(td, v); if (lut < 0) goto out; td->lut[0] = lut; td->lut_bottom = 0; for (j = 1, rate = 0; ; rate++) { struct dev_pm_opp *opp; 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->cvb->min_millivolts * 1000) td->dvco_rate_min = dev_pm_opp_get_freq(opp); dev_pm_opp_put(opp); for (;;) { v += max(1UL, (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->lut[j - 1]) td->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->lut[j - 1]) td->lut[j++] = selector; if (v >= v_max) break; } td->lut_size = j; if (!td->dvco_rate_min) dev_err(td->dev, "no opp above DFLL minimum voltage %d mV\n", td->soc->cvb->min_millivolts); else { ret = 0; for (j = 0; j < td->lut_size; j++) td->lut_uv[j] = regulator_list_voltage(td->vdd_reg, td->lut[j]); } out: return ret; } static int dfll_build_lut(struct tegra_dfll *td) { unsigned long rate, v_max; struct dev_pm_opp *opp; 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"); return -EINVAL; } v_max = dev_pm_opp_get_voltage(opp); dev_pm_opp_put(opp); if (td->pmu_if == TEGRA_DFLL_PMU_PWM) return dfll_build_pwm_lut(td, v_max); else return dfll_build_i2c_lut(td, v_max); } /** * 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; return 0; } static int dfll_fetch_pwm_params(struct tegra_dfll *td) { int ret, i; u32 pwm_period; if (!td->soc->alignment.step_uv || !td->soc->alignment.offset_uv) { dev_err(td->dev, "Missing step or alignment info for PWM regulator"); return -EINVAL; } for (i = 0; i < MAX_DFLL_VOLTAGES; i++) td->lut_uv[i] = td->soc->alignment.offset_uv + i * td->soc->alignment.step_uv; ret = read_dt_param(td, "nvidia,pwm-tristate-microvolts", &td->reg_init_uV); if (!ret) { dev_err(td->dev, "couldn't get initialized voltage\n"); return ret; } ret = read_dt_param(td, "nvidia,pwm-period-nanoseconds", &pwm_period); if (!ret) { dev_err(td->dev, "couldn't get PWM period\n"); return ret; } td->pwm_rate = (NSEC_PER_SEC / pwm_period) * (MAX_DFLL_VOLTAGES - 1); td->pwm_pin = devm_pinctrl_get(td->dev); if (IS_ERR(td->pwm_pin)) { dev_err(td->dev, "DT: missing pinctrl device\n"); return PTR_ERR(td->pwm_pin); } td->pwm_enable_state = pinctrl_lookup_state(td->pwm_pin, "dvfs_pwm_enable"); if (IS_ERR(td->pwm_enable_state)) { dev_err(td->dev, "DT: missing pwm enabled state\n"); return PTR_ERR(td->pwm_enable_state); } td->pwm_disable_state = pinctrl_lookup_state(td->pwm_pin, "dvfs_pwm_disable"); if (IS_ERR(td->pwm_disable_state)) { dev_err(td->dev, "DT: missing pwm disabled state\n"); return PTR_ERR(td->pwm_disable_state); } 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->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; } if (of_property_read_bool(td->dev->of_node, "nvidia,pwm-to-pmic")) { td->pmu_if = TEGRA_DFLL_PMU_PWM; ret = dfll_fetch_pwm_params(td); } else { 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->pmu_if = TEGRA_DFLL_PMU_I2C; ret = dfll_fetch_i2c_params(td); } if (ret) return ret; ret = dfll_build_lut(td); if (ret) { dev_err(td->dev, "couldn't build LUT\n"); 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; } dfll_debug_init(td); 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 a * soc pointer upon success or -EBUSY if the DFLL is still active. */ struct tegra_dfll_soc_data *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 ERR_PTR(-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 td->soc; } EXPORT_SYMBOL(tegra_dfll_unregister);