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Diffstat (limited to 'drivers/clk/tegra/clk-dfll.c')
| -rw-r--r-- | drivers/clk/tegra/clk-dfll.c | 1738 |
1 files changed, 1738 insertions, 0 deletions
diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c new file mode 100644 index 000000000..48ee43734 --- /dev/null +++ b/drivers/clk/tegra/clk-dfll.c @@ -0,0 +1,1738 @@ +/* + * 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" +#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, +}; + +/** + * 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->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); +} + +/* + * DFLL-to-I2C controller interface + */ + +/** + * dfll_i2c_set_output_enabled - enable/disable I2C PMIC voltage requests + * @td: DFLL instance + * @enable: whether to enable or disable the I2C voltage requests + * + * Set the master enable control for I2C control value updates. If disabled, + * then I2C control messages are inhibited, regardless of the DFLL mode. + */ +static int dfll_i2c_set_output_enabled(struct tegra_dfll *td, bool enable) +{ + u32 val; + + val = dfll_i2c_readl(td, DFLL_OUTPUT_CFG); + + if (enable) + val |= DFLL_OUTPUT_CFG_I2C_ENABLE; + else + val &= ~DFLL_OUTPUT_CFG_I2C_ENABLE; + + dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG); + dfll_i2c_wmb(td); + + return 0; +} + +/** + * dfll_load_lut - load the voltage lookup table + * @td: struct tegra_dfll * + * + * Load the voltage-to-PMIC register value lookup table into the DFLL + * IP block memory. Look-up tables can be loaded at any time. + */ +static void dfll_load_i2c_lut(struct tegra_dfll *td) +{ + int i, lut_index; + u32 val; + + for (i = 0; i < MAX_DFLL_VOLTAGES; i++) { + if (i < td->lut_min) + lut_index = td->lut_min; + else if (i > td->lut_max) + lut_index = td->lut_max; + else + lut_index = i; + + val = regulator_list_hardware_vsel(td->vdd_reg, + td->i2c_lut[lut_index]); + __raw_writel(val, td->lut_base + i * 4); + } + + dfll_i2c_wmb(td); +} + +/** + * dfll_init_i2c_if - set up the DFLL's DFLL-I2C interface + * @td: DFLL instance + * + * During DFLL driver initialization, program the DFLL-I2C interface + * with the PMU slave address, vdd register offset, and transfer mode. + * This data is used by the DFLL to automatically construct I2C + * voltage-set commands, which are then passed to the DFLL's internal + * I2C controller. + */ +static void dfll_init_i2c_if(struct tegra_dfll *td) +{ + u32 val; + + if (td->i2c_slave_addr > 0x7f) { + val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT; + val |= DFLL_I2C_CFG_SLAVE_ADDR_10; + } else { + val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT; + } + val |= DFLL_I2C_CFG_SIZE_MASK; + val |= DFLL_I2C_CFG_ARB_ENABLE; + dfll_i2c_writel(td, val, DFLL_I2C_CFG); + + dfll_i2c_writel(td, td->i2c_reg, DFLL_I2C_VDD_REG_ADDR); + + val = DIV_ROUND_UP(td->i2c_clk_rate, td->i2c_fs_rate * 8); + BUG_ON(!val || (val > DFLL_I2C_CLK_DIVISOR_MASK)); + val = (val - 1) << DFLL_I2C_CLK_DIVISOR_FS_SHIFT; + + /* default hs divisor just in case */ + val |= 1 << DFLL_I2C_CLK_DIVISOR_HS_SHIFT; + __raw_writel(val, td->i2c_controller_base + DFLL_I2C_CLK_DIVISOR); + dfll_i2c_wmb(td); +} + +/** + * dfll_init_out_if - prepare DFLL-to-PMIC interface + * @td: DFLL instance + * + * During DFLL driver initialization or resume from context loss, + * disable the I2C command output to the PMIC, set safe voltage and + * output limits, and disable and clear limit interrupts. + */ +static void dfll_init_out_if(struct tegra_dfll *td) +{ + u32 val; + + td->lut_min = 0; + td->lut_max = td->i2c_lut_size - 1; + td->lut_safe = td->lut_min + 1; + + dfll_i2c_writel(td, 0, DFLL_OUTPUT_CFG); + val = (td->lut_safe << DFLL_OUTPUT_CFG_SAFE_SHIFT) | + (td->lut_max << DFLL_OUTPUT_CFG_MAX_SHIFT) | + (td->lut_min << DFLL_OUTPUT_CFG_MIN_SHIFT); + dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG); + dfll_i2c_wmb(td); + + dfll_writel(td, 0, DFLL_OUTPUT_FORCE); + dfll_i2c_writel(td, 0, DFLL_INTR_EN); + dfll_i2c_writel(td, DFLL_INTR_MAX_MASK | DFLL_INTR_MIN_MASK, + DFLL_INTR_STS); + + dfll_load_i2c_lut(td); + dfll_init_i2c_if(td); +} + +/* + * Set/get the DFLL's targeted output clock rate + */ + +/** + * find_lut_index_for_rate - determine I2C LUT index for given DFLL rate + * @td: DFLL instance + * @rate: clock rate + * + * Determines the index of a I2C LUT entry for a voltage that approximately + * produces the given DFLL clock rate. This is used when forcing a value + * to the integrator during rate changes. Returns -ENOENT if a suitable + * LUT index is not found. + */ +static int find_lut_index_for_rate(struct tegra_dfll *td, unsigned long rate) +{ + struct dev_pm_opp *opp; + int i, uv; + + opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate); + if (IS_ERR(opp)) + return PTR_ERR(opp); + + uv = dev_pm_opp_get_voltage(opp); + dev_pm_opp_put(opp); + + for (i = 0; i < td->i2c_lut_size; i++) { + if (regulator_list_voltage(td->vdd_reg, td->i2c_lut[i]) == uv) + return i; + } + + return -ENOENT; +} + +/** + * dfll_calculate_rate_request - calculate DFLL parameters for a given rate + * @td: DFLL instance + * @req: DFLL-rate-request structure + * @rate: the desired DFLL rate + * + * Populate the DFLL-rate-request record @req fields with the scale_bits + * and mult_bits fields, based on the target input rate. Returns 0 upon + * success, or -EINVAL if the requested rate in req->rate is too high + * or low for the DFLL to generate. + */ +static int dfll_calculate_rate_request(struct tegra_dfll *td, + struct dfll_rate_req *req, + unsigned long rate) +{ + u32 val; + + /* + * If requested rate is below the minimum DVCO rate, active the scaler. + * In the future the DVCO minimum voltage should be selected based on + * chip temperature and the actual minimum rate should be calibrated + * at runtime. + */ + req->scale_bits = DFLL_FREQ_REQ_SCALE_MAX - 1; + if (rate < td->dvco_rate_min) { + int scale; + + scale = DIV_ROUND_CLOSEST(rate / 1000 * DFLL_FREQ_REQ_SCALE_MAX, + td->dvco_rate_min / 1000); + if (!scale) { + dev_err(td->dev, "%s: Rate %lu is too low\n", + __func__, rate); + return -EINVAL; + } + req->scale_bits = scale - 1; + rate = td->dvco_rate_min; + } + + /* Convert requested rate into frequency request and scale settings */ + val = DVCO_RATE_TO_MULT(rate, td->ref_rate); + if (val > FREQ_MAX) { + dev_err(td->dev, "%s: Rate %lu is above dfll range\n", + __func__, rate); + return -EINVAL; + } + req->mult_bits = val; + req->dvco_target_rate = MULT_TO_DVCO_RATE(req->mult_bits, td->ref_rate); + req->rate = dfll_scale_dvco_rate(req->scale_bits, + req->dvco_target_rate); + req->lut_index = find_lut_index_for_rate(td, req->dvco_target_rate); + if (req->lut_index < 0) + return req->lut_index; + + return 0; +} + +/** + * dfll_set_frequency_request - start the frequency change operation + * @td: DFLL instance + * @req: rate request structure + * + * Tell the DFLL to try to change its output frequency to the + * frequency represented by @req. DFLL must be in closed-loop mode. + */ +static void dfll_set_frequency_request(struct tegra_dfll *td, + struct dfll_rate_req *req) +{ + u32 val = 0; + int force_val; + int coef = 128; /* FIXME: td->cg_scale? */; + + force_val = (req->lut_index - td->lut_safe) * coef / td->cg; + force_val = clamp(force_val, FORCE_MIN, FORCE_MAX); + + val |= req->mult_bits << DFLL_FREQ_REQ_MULT_SHIFT; + val |= req->scale_bits << DFLL_FREQ_REQ_SCALE_SHIFT; + val |= ((u32)force_val << DFLL_FREQ_REQ_FORCE_SHIFT) & + DFLL_FREQ_REQ_FORCE_MASK; + val |= DFLL_FREQ_REQ_FREQ_VALID | DFLL_FREQ_REQ_FORCE_ENABLE; + + dfll_writel(td, val, DFLL_FREQ_REQ); + dfll_wmb(td); +} + +/** + * tegra_dfll_request_rate - set the next rate for the DFLL to tune to + * @td: DFLL instance + * @rate: clock rate to target + * + * Convert the requested clock rate @rate into the DFLL control logic + * settings. In closed-loop mode, update new settings immediately to + * adjust DFLL output rate accordingly. Otherwise, just save them + * until the next switch to closed loop. Returns 0 upon success, + * -EPERM if the DFLL driver has not yet been initialized, or -EINVAL + * if @rate is outside the DFLL's tunable range. + */ +static int dfll_request_rate(struct tegra_dfll *td, unsigned long rate) +{ + int ret; + struct dfll_rate_req req; + + if (td->mode == DFLL_UNINITIALIZED) { + dev_err(td->dev, "%s: Cannot set DFLL rate in %s mode\n", + __func__, mode_name[td->mode]); + return -EPERM; + } + + ret = dfll_calculate_rate_request(td, &req, rate); + if (ret) + return ret; + + td->last_unrounded_rate = rate; + td->last_req = req; + + if (td->mode == DFLL_CLOSED_LOOP) + dfll_set_frequency_request(td, &td->last_req); + + return 0; +} + +/* + * DFLL enable/disable & open-loop <-> closed-loop transitions + */ + +/** + * dfll_disable - switch from open-loop mode to disabled mode + * @td: DFLL instance + * + * Switch from OPEN_LOOP state to DISABLED state. Returns 0 upon success + * or -EPERM if the DFLL is not currently in open-loop mode. + */ +static int dfll_disable(struct tegra_dfll *td) +{ + if (td->mode != DFLL_OPEN_LOOP) { + dev_err(td->dev, "cannot disable DFLL in %s mode\n", + mode_name[td->mode]); + return -EINVAL; + } + + dfll_set_mode(td, DFLL_DISABLED); + pm_runtime_put_sync(td->dev); + + return 0; +} + +/** + * dfll_enable - switch a disabled DFLL to open-loop mode + * @td: DFLL instance + * + * Switch from DISABLED state to OPEN_LOOP state. Returns 0 upon success + * or -EPERM if the DFLL is not currently disabled. + */ +static int dfll_enable(struct tegra_dfll *td) +{ + if (td->mode != DFLL_DISABLED) { + dev_err(td->dev, "cannot enable DFLL in %s mode\n", + mode_name[td->mode]); + return -EPERM; + } + + pm_runtime_get_sync(td->dev); + dfll_set_mode(td, DFLL_OPEN_LOOP); + + return 0; +} + +/** + * dfll_set_open_loop_config - prepare to switch to open-loop mode + * @td: DFLL instance + * + * Prepare to switch the DFLL to open-loop mode. This switches the + * DFLL to the low-voltage tuning range, ensures that I2C output + * forcing is disabled, and disables the output clock rate scaler. + * The DFLL's low-voltage tuning range parameters must be + * characterized to keep the downstream device stable at any DVCO + * input voltage. No return value. + */ +static void dfll_set_open_loop_config(struct tegra_dfll *td) +{ + u32 val; + + /* always tune low (safe) in open loop */ + if (td->tune_range != DFLL_TUNE_LOW) + dfll_tune_low(td); + + val = dfll_readl(td, DFLL_FREQ_REQ); + val |= DFLL_FREQ_REQ_SCALE_MASK; + val &= ~DFLL_FREQ_REQ_FORCE_ENABLE; + dfll_writel(td, val, DFLL_FREQ_REQ); + dfll_wmb(td); +} + +/** + * tegra_dfll_lock - switch from open-loop to closed-loop mode + * @td: DFLL instance + * + * Switch from OPEN_LOOP state to CLOSED_LOOP state. Returns 0 upon success, + * -EINVAL if the DFLL's target rate hasn't been set yet, or -EPERM if the + * DFLL is not currently in open-loop mode. + */ +static int dfll_lock(struct tegra_dfll *td) +{ + struct dfll_rate_req *req = &td->last_req; + + switch (td->mode) { + case DFLL_CLOSED_LOOP: + return 0; + + case DFLL_OPEN_LOOP: + if (req->rate == 0) { + dev_err(td->dev, "%s: Cannot lock DFLL at rate 0\n", + __func__); + return -EINVAL; + } + + dfll_i2c_set_output_enabled(td, true); + dfll_set_mode(td, DFLL_CLOSED_LOOP); + dfll_set_frequency_request(td, req); + return 0; + + default: + BUG_ON(td->mode > DFLL_CLOSED_LOOP); + dev_err(td->dev, "%s: Cannot lock DFLL in %s mode\n", + __func__, mode_name[td->mode]); + return -EPERM; + } +} + +/** + * tegra_dfll_unlock - switch from closed-loop to open-loop mode + * @td: DFLL instance + * + * Switch from CLOSED_LOOP state to OPEN_LOOP state. Returns 0 upon success, + * or -EPERM if the DFLL is not currently in open-loop mode. + */ +static int dfll_unlock(struct tegra_dfll *td) +{ + switch (td->mode) { + case DFLL_CLOSED_LOOP: + dfll_set_open_loop_config(td); + dfll_set_mode(td, DFLL_OPEN_LOOP); + dfll_i2c_set_output_enabled(td, false); + return 0; + + case DFLL_OPEN_LOOP: + return 0; + + default: + BUG_ON(td->mode > DFLL_CLOSED_LOOP); + dev_err(td->dev, "%s: Cannot unlock DFLL in %s mode\n", + __func__, mode_name[td->mode]); + return -EPERM; + } +} + +/* + * Clock framework integration + * + * When the DFLL is being controlled by the CCF, always enter closed loop + * mode when the clk is enabled. This requires that a DFLL rate request + * has been set beforehand, which implies that a clk_set_rate() call is + * always required before a clk_enable(). + */ + +static int dfll_clk_is_enabled(struct clk_hw *hw) +{ + struct tegra_dfll *td = clk_hw_to_dfll(hw); + + return dfll_is_running(td); +} + +static int dfll_clk_enable(struct clk_hw *hw) +{ + struct tegra_dfll *td = clk_hw_to_dfll(hw); + int ret; + + ret = dfll_enable(td); + if (ret) + return ret; + + ret = dfll_lock(td); + if (ret) + dfll_disable(td); + + return ret; +} + +static void dfll_clk_disable(struct clk_hw *hw) +{ + struct tegra_dfll *td = clk_hw_to_dfll(hw); + int ret; + + ret = dfll_unlock(td); + if (!ret) + dfll_disable(td); +} + +static unsigned long dfll_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct tegra_dfll *td = clk_hw_to_dfll(hw); + + return td->last_unrounded_rate; +} + +/* 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_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 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("enable", S_IRUGO | S_IWUSR, root, td, &enable_fops); + debugfs_create_file("lock", S_IRUGO, root, td, &lock_fops); + debugfs_create_file("rate", S_IRUGO, root, td, &rate_fops); + debugfs_create_file("registers", S_IRUGO, 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_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; + + 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); + dev_pm_opp_put(opp); + + v = td->soc->cvb->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->cvb->min_millivolts * 1000) + td->dvco_rate_min = dev_pm_opp_get_freq(opp); + + dev_pm_opp_put(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->cvb->min_millivolts); + else + ret = 0; + +out: + 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; + } + + 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); |