diff options
Diffstat (limited to 'drivers/clk/tegra/clk-dfll.c')
| -rw-r--r-- | drivers/clk/tegra/clk-dfll.c | 1095 |
1 files changed, 1095 insertions, 0 deletions
diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c new file mode 100644 index 000000000000..fb138bfa0af2 --- /dev/null +++ b/drivers/clk/tegra/clk-dfll.c @@ -0,0 +1,1095 @@ +/* + * clk-dfll.c - Tegra DFLL clock source common code + * + * Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved. + * + * Aleksandr Frid <afrid@nvidia.com> + * Paul Walmsley <pwalmsley@nvidia.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * This library is for the DVCO and DFLL IP blocks on the Tegra124 + * SoC. These IP blocks together are also known at NVIDIA as + * "CL-DVFS". To try to avoid confusion, this code refers to them + * collectively as the "DFLL." + * + * The DFLL is a root clocksource which tolerates some amount of + * supply voltage noise. Tegra124 uses it to clock the fast CPU + * complex when the target CPU speed is above a particular rate. The + * DFLL can be operated in either open-loop mode or closed-loop mode. + * In open-loop mode, the DFLL generates an output clock appropriate + * to the supply voltage. In closed-loop mode, when configured with a + * target frequency, the DFLL minimizes supply voltage while + * delivering an average frequency equal to the target. + * + * Devices clocked by the DFLL must be able to tolerate frequency + * variation. In the case of the CPU, it's important to note that the + * CPU cycle time will vary. This has implications for + * performance-measurement code and any code that relies on the CPU + * cycle time to delay for a certain length of time. + * + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/debugfs.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pm_opp.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/reset.h> +#include <linux/seq_file.h> + +#include "clk-dfll.h" + +/* + * DFLL control registers - access via dfll_{readl,writel} + */ + +/* DFLL_CTRL: DFLL control register */ +#define DFLL_CTRL 0x00 +#define DFLL_CTRL_MODE_MASK 0x03 + +/* DFLL_CONFIG: DFLL sample rate control */ +#define DFLL_CONFIG 0x04 +#define DFLL_CONFIG_DIV_MASK 0xff +#define DFLL_CONFIG_DIV_PRESCALE 32 + +/* DFLL_PARAMS: tuning coefficients for closed loop integrator */ +#define DFLL_PARAMS 0x08 +#define DFLL_PARAMS_CG_SCALE (0x1 << 24) +#define DFLL_PARAMS_FORCE_MODE_SHIFT 22 +#define DFLL_PARAMS_FORCE_MODE_MASK (0x3 << DFLL_PARAMS_FORCE_MODE_SHIFT) +#define DFLL_PARAMS_CF_PARAM_SHIFT 16 +#define DFLL_PARAMS_CF_PARAM_MASK (0x3f << DFLL_PARAMS_CF_PARAM_SHIFT) +#define DFLL_PARAMS_CI_PARAM_SHIFT 8 +#define DFLL_PARAMS_CI_PARAM_MASK (0x7 << DFLL_PARAMS_CI_PARAM_SHIFT) +#define DFLL_PARAMS_CG_PARAM_SHIFT 0 +#define DFLL_PARAMS_CG_PARAM_MASK (0xff << DFLL_PARAMS_CG_PARAM_SHIFT) + +/* DFLL_TUNE0: delay line configuration register 0 */ +#define DFLL_TUNE0 0x0c + +/* DFLL_TUNE1: delay line configuration register 1 */ +#define DFLL_TUNE1 0x10 + +/* DFLL_FREQ_REQ: target DFLL frequency control */ +#define DFLL_FREQ_REQ 0x14 +#define DFLL_FREQ_REQ_FORCE_ENABLE (0x1 << 28) +#define DFLL_FREQ_REQ_FORCE_SHIFT 16 +#define DFLL_FREQ_REQ_FORCE_MASK (0xfff << DFLL_FREQ_REQ_FORCE_SHIFT) +#define FORCE_MAX 2047 +#define FORCE_MIN -2048 +#define DFLL_FREQ_REQ_SCALE_SHIFT 8 +#define DFLL_FREQ_REQ_SCALE_MASK (0xff << DFLL_FREQ_REQ_SCALE_SHIFT) +#define DFLL_FREQ_REQ_SCALE_MAX 256 +#define DFLL_FREQ_REQ_FREQ_VALID (0x1 << 7) +#define DFLL_FREQ_REQ_MULT_SHIFT 0 +#define DFLL_FREQ_REG_MULT_MASK (0x7f << DFLL_FREQ_REQ_MULT_SHIFT) +#define FREQ_MAX 127 + +/* DFLL_DROOP_CTRL: droop prevention control */ +#define DFLL_DROOP_CTRL 0x1c + +/* DFLL_OUTPUT_CFG: closed loop mode control registers */ +/* NOTE: access via dfll_i2c_{readl,writel} */ +#define DFLL_OUTPUT_CFG 0x20 +#define DFLL_OUTPUT_CFG_I2C_ENABLE (0x1 << 30) +#define OUT_MASK 0x3f +#define DFLL_OUTPUT_CFG_SAFE_SHIFT 24 +#define DFLL_OUTPUT_CFG_SAFE_MASK \ + (OUT_MASK << DFLL_OUTPUT_CFG_SAFE_SHIFT) +#define DFLL_OUTPUT_CFG_MAX_SHIFT 16 +#define DFLL_OUTPUT_CFG_MAX_MASK \ + (OUT_MASK << DFLL_OUTPUT_CFG_MAX_SHIFT) +#define DFLL_OUTPUT_CFG_MIN_SHIFT 8 +#define DFLL_OUTPUT_CFG_MIN_MASK \ + (OUT_MASK << DFLL_OUTPUT_CFG_MIN_SHIFT) +#define DFLL_OUTPUT_CFG_PWM_DELTA (0x1 << 7) +#define DFLL_OUTPUT_CFG_PWM_ENABLE (0x1 << 6) +#define DFLL_OUTPUT_CFG_PWM_DIV_SHIFT 0 +#define DFLL_OUTPUT_CFG_PWM_DIV_MASK \ + (OUT_MASK << DFLL_OUTPUT_CFG_PWM_DIV_SHIFT) + +/* DFLL_OUTPUT_FORCE: closed loop mode voltage forcing control */ +#define DFLL_OUTPUT_FORCE 0x24 +#define DFLL_OUTPUT_FORCE_ENABLE (0x1 << 6) +#define DFLL_OUTPUT_FORCE_VALUE_SHIFT 0 +#define DFLL_OUTPUT_FORCE_VALUE_MASK \ + (OUT_MASK << DFLL_OUTPUT_FORCE_VALUE_SHIFT) + +/* DFLL_MONITOR_CTRL: internal monitor data source control */ +#define DFLL_MONITOR_CTRL 0x28 +#define DFLL_MONITOR_CTRL_FREQ 6 + +/* DFLL_MONITOR_DATA: internal monitor data output */ +#define DFLL_MONITOR_DATA 0x2c +#define DFLL_MONITOR_DATA_NEW_MASK (0x1 << 16) +#define DFLL_MONITOR_DATA_VAL_SHIFT 0 +#define DFLL_MONITOR_DATA_VAL_MASK (0xFFFF << DFLL_MONITOR_DATA_VAL_SHIFT) + +/* + * I2C output control registers - access via dfll_i2c_{readl,writel} + */ + +/* DFLL_I2C_CFG: I2C controller configuration register */ +#define DFLL_I2C_CFG 0x40 +#define DFLL_I2C_CFG_ARB_ENABLE (0x1 << 20) +#define DFLL_I2C_CFG_HS_CODE_SHIFT 16 +#define DFLL_I2C_CFG_HS_CODE_MASK (0x7 << DFLL_I2C_CFG_HS_CODE_SHIFT) +#define DFLL_I2C_CFG_PACKET_ENABLE (0x1 << 15) +#define DFLL_I2C_CFG_SIZE_SHIFT 12 +#define DFLL_I2C_CFG_SIZE_MASK (0x7 << DFLL_I2C_CFG_SIZE_SHIFT) +#define DFLL_I2C_CFG_SLAVE_ADDR_10 (0x1 << 10) +#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT 1 +#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT 0 + +/* DFLL_I2C_VDD_REG_ADDR: PMIC I2C address for closed loop mode */ +#define DFLL_I2C_VDD_REG_ADDR 0x44 + +/* DFLL_I2C_STS: I2C controller status */ +#define DFLL_I2C_STS 0x48 +#define DFLL_I2C_STS_I2C_LAST_SHIFT 1 +#define DFLL_I2C_STS_I2C_REQ_PENDING 0x1 + +/* DFLL_INTR_STS: DFLL interrupt status register */ +#define DFLL_INTR_STS 0x5c + +/* DFLL_INTR_EN: DFLL interrupt enable register */ +#define DFLL_INTR_EN 0x60 +#define DFLL_INTR_MIN_MASK 0x1 +#define DFLL_INTR_MAX_MASK 0x2 + +/* + * Integrated I2C controller registers - relative to td->i2c_controller_base + */ + +/* DFLL_I2C_CLK_DIVISOR: I2C controller clock divisor */ +#define DFLL_I2C_CLK_DIVISOR 0x6c +#define DFLL_I2C_CLK_DIVISOR_MASK 0xffff +#define DFLL_I2C_CLK_DIVISOR_FS_SHIFT 16 +#define DFLL_I2C_CLK_DIVISOR_HS_SHIFT 0 +#define DFLL_I2C_CLK_DIVISOR_PREDIV 8 +#define DFLL_I2C_CLK_DIVISOR_HSMODE_PREDIV 12 + +/* + * Other constants + */ + +/* MAX_DFLL_VOLTAGES: number of LUT entries in the DFLL IP block */ +#define MAX_DFLL_VOLTAGES 33 + +/* + * REF_CLK_CYC_PER_DVCO_SAMPLE: the number of ref_clk cycles that the hardware + * integrates the DVCO counter over - used for debug rate monitoring and + * droop control + */ +#define REF_CLK_CYC_PER_DVCO_SAMPLE 4 + +/* + * REF_CLOCK_RATE: the DFLL reference clock rate currently supported by this + * driver, in Hz + */ +#define REF_CLOCK_RATE 51000000UL + + +/** + * 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 + * + * 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, +}; + +/** + * 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 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; + + /* Parameters from DT */ + u32 droop_ctrl; +}; + +#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", +}; + +/* + * Register accessors + */ + +static inline u32 dfll_readl(struct tegra_dfll *td, u32 offs) +{ + return __raw_readl(td->base + offs); +} + +static inline void dfll_writel(struct tegra_dfll *td, u32 val, u32 offs) +{ + WARN_ON(offs >= DFLL_I2C_CFG); + __raw_writel(val, td->base + offs); +} + +static inline void dfll_wmb(struct tegra_dfll *td) +{ + dfll_readl(td, DFLL_CTRL); +} + +/* I2C output control registers - for addresses above DFLL_I2C_CFG */ + +static inline u32 dfll_i2c_readl(struct tegra_dfll *td, u32 offs) +{ + return __raw_readl(td->i2c_base + offs); +} + +static inline void dfll_i2c_writel(struct tegra_dfll *td, u32 val, u32 offs) +{ + __raw_writel(val, td->i2c_base + offs); +} + +static inline void dfll_i2c_wmb(struct tegra_dfll *td) +{ + dfll_i2c_readl(td, DFLL_I2C_CFG); +} + +/** + * dfll_is_running - is the DFLL currently generating a clock? + * @td: DFLL instance + * + * If the DFLL is currently generating an output clock signal, return + * true; otherwise return false. + */ +static bool dfll_is_running(struct tegra_dfll *td) +{ + return td->mode >= DFLL_OPEN_LOOP; +} + +/* + * Runtime PM suspend/resume callbacks + */ + +/** + * tegra_dfll_runtime_resume - enable all clocks needed by the DFLL + * @dev: DFLL device * + * + * Enable all clocks needed by the DFLL. Assumes that clk_prepare() + * has already been called on all the clocks. + * + * XXX Should also handle context restore when returning from off. + */ +int tegra_dfll_runtime_resume(struct device *dev) +{ + struct tegra_dfll *td = dev_get_drvdata(dev); + int ret; + + ret = clk_enable(td->ref_clk); + if (ret) { + dev_err(dev, "could not enable ref clock: %d\n", ret); + return ret; + } + + ret = clk_enable(td->soc_clk); + if (ret) { + dev_err(dev, "could not enable register clock: %d\n", ret); + clk_disable(td->ref_clk); + return ret; + } + + ret = clk_enable(td->i2c_clk); + if (ret) { + dev_err(dev, "could not enable i2c clock: %d\n", ret); + clk_disable(td->soc_clk); + clk_disable(td->ref_clk); + return ret; + } + + return 0; +} +EXPORT_SYMBOL(tegra_dfll_runtime_resume); + +/** + * tegra_dfll_runtime_suspend - disable all clocks needed by the DFLL + * @dev: DFLL device * + * + * Disable all clocks needed by the DFLL. Assumes that other code + * will later call clk_unprepare(). + */ +int tegra_dfll_runtime_suspend(struct device *dev) +{ + struct tegra_dfll *td = dev_get_drvdata(dev); + + clk_disable(td->ref_clk); + clk_disable(td->soc_clk); + clk_disable(td->i2c_clk); + + return 0; +} +EXPORT_SYMBOL(tegra_dfll_runtime_suspend); + +/* + * DFLL tuning operations (per-voltage-range tuning settings) + */ + +/** + * dfll_tune_low - tune to DFLL and CPU settings valid for any voltage + * @td: DFLL instance + * + * Tune the DFLL oscillator parameters and the CPU clock shaper for + * the low-voltage range. These settings are valid for any voltage, + * but may not be optimal. + */ +static void dfll_tune_low(struct tegra_dfll *td) +{ + td->tune_range = DFLL_TUNE_LOW; + + dfll_writel(td, td->soc->tune0_low, DFLL_TUNE0); + dfll_writel(td, td->soc->tune1, DFLL_TUNE1); + dfll_wmb(td); + + if (td->soc->set_clock_trimmers_low) + td->soc->set_clock_trimmers_low(); +} + +/* + * Output clock scaler helpers + */ + +/** + * dfll_scale_dvco_rate - calculate scaled rate from the DVCO rate + * @scale_bits: clock scaler value (bits in the DFLL_FREQ_REQ_SCALE field) + * @dvco_rate: the DVCO rate + * + * Apply the same scaling formula that the DFLL hardware uses to scale + * the DVCO rate. + */ +static unsigned long dfll_scale_dvco_rate(int scale_bits, + unsigned long dvco_rate) +{ + return (u64)dvco_rate * (scale_bits + 1) / DFLL_FREQ_REQ_SCALE_MAX; +} + +/* + * Monitor control + */ + +/** + * dfll_calc_monitored_rate - convert DFLL_MONITOR_DATA_VAL rate into real freq + * @monitor_data: value read from the DFLL_MONITOR_DATA_VAL bitfield + * @ref_rate: DFLL reference clock rate + * + * Convert @monitor_data from DFLL_MONITOR_DATA_VAL units into cycles + * per second. Returns the converted value. + */ +static u64 dfll_calc_monitored_rate(u32 monitor_data, + unsigned long ref_rate) +{ + return monitor_data * (ref_rate / REF_CLK_CYC_PER_DVCO_SAMPLE); +} + +/** + * dfll_read_monitor_rate - return the DFLL's output rate from internal monitor + * @td: DFLL instance + * + * If the DFLL is enabled, return the last rate reported by the DFLL's + * internal monitoring hardware. This works in both open-loop and + * closed-loop mode, and takes the output scaler setting into account. + * Assumes that the monitor was programmed to monitor frequency before + * the sample period started. If the driver believes that the DFLL is + * currently uninitialized or disabled, it will return 0, since + * otherwise the DFLL monitor data register will return the last + * measured rate from when the DFLL was active. + */ +static u64 dfll_read_monitor_rate(struct tegra_dfll *td) +{ + u32 v, s; + u64 pre_scaler_rate, post_scaler_rate; + + if (!dfll_is_running(td)) + return 0; + + v = dfll_readl(td, DFLL_MONITOR_DATA); + v = (v & DFLL_MONITOR_DATA_VAL_MASK) >> DFLL_MONITOR_DATA_VAL_SHIFT; + pre_scaler_rate = dfll_calc_monitored_rate(v, td->ref_rate); + + s = dfll_readl(td, DFLL_FREQ_REQ); + s = (s & DFLL_FREQ_REQ_SCALE_MASK) >> DFLL_FREQ_REQ_SCALE_SHIFT; + post_scaler_rate = dfll_scale_dvco_rate(s, pre_scaler_rate); + + return post_scaler_rate; +} + +/* + * DFLL mode switching + */ + +/** + * dfll_set_mode - change the DFLL control mode + * @td: DFLL instance + * @mode: DFLL control mode (see enum dfll_ctrl_mode) + * + * Change the DFLL's operating mode between disabled, open-loop mode, + * and closed-loop mode, or vice versa. + */ +static void dfll_set_mode(struct tegra_dfll *td, + enum dfll_ctrl_mode mode) +{ + td->mode = mode; + dfll_writel(td, mode - 1, DFLL_CTRL); + dfll_wmb(td); +} + +/* + * DFLL 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); +} + +/* + * Clock framework integration + */ + +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); + + return dfll_enable(td); +} + +static void dfll_clk_disable(struct clk_hw *hw) +{ + struct tegra_dfll *td = clk_hw_to_dfll(hw); + + dfll_disable(td); +} + +static const struct clk_ops dfll_clk_ops = { + .is_enabled = dfll_clk_is_enabled, + .enable = dfll_clk_enable, + .disable = dfll_clk_disable, +}; + +static struct clk_init_data dfll_clk_init_data = { + .flags = CLK_IS_ROOT, + .ops = &dfll_clk_ops, + .num_parents = 0, +}; + +/** + * dfll_register_clk - register the DFLL output clock with the clock framework + * @td: DFLL instance + * + * Register the DFLL's output clock with the Linux clock framework and register + * the DFLL driver as an OF clock provider. Returns 0 upon success or -EINVAL + * or -ENOMEM upon failure. + */ +static int dfll_register_clk(struct tegra_dfll *td) +{ + int ret; + + dfll_clk_init_data.name = td->output_clock_name; + td->dfll_clk_hw.init = &dfll_clk_init_data; + + td->dfll_clk = clk_register(td->dev, &td->dfll_clk_hw); + if (IS_ERR(td->dfll_clk)) { + dev_err(td->dev, "DFLL clock registration error\n"); + return -EINVAL; + } + + ret = of_clk_add_provider(td->dev->of_node, of_clk_src_simple_get, + td->dfll_clk); + if (ret) { + dev_err(td->dev, "of_clk_add_provider() failed\n"); + + clk_unregister(td->dfll_clk); + return ret; + } + + return 0; +} + +/** + * dfll_unregister_clk - unregister the DFLL output clock + * @td: DFLL instance + * + * Unregister the DFLL's output clock from the Linux clock framework + * and from clkdev. No return value. + */ +static void dfll_unregister_clk(struct tegra_dfll *td) +{ + of_clk_del_provider(td->dev->of_node); + clk_unregister(td->dfll_clk); + td->dfll_clk = NULL; +} + +/* + * Debugfs interface + */ + +#ifdef CONFIG_DEBUG_FS + +static int attr_enable_get(void *data, u64 *val) +{ + struct tegra_dfll *td = data; + + *val = dfll_is_running(td); + + return 0; +} +static int attr_enable_set(void *data, u64 val) +{ + struct tegra_dfll *td = data; + + return val ? dfll_enable(td) : dfll_disable(td); +} +DEFINE_SIMPLE_ATTRIBUTE(enable_fops, attr_enable_get, attr_enable_set, + "%llu\n"); + +static int attr_rate_get(void *data, u64 *val) +{ + struct tegra_dfll *td = data; + + *val = dfll_read_monitor_rate(td); + + return 0; +} +DEFINE_SIMPLE_ATTRIBUTE(rate_fops, attr_rate_get, NULL, "%llu\n"); + +static int attr_registers_show(struct seq_file *s, void *data) +{ + u32 val, offs; + struct tegra_dfll *td = s->private; + + seq_puts(s, "CONTROL REGISTERS:\n"); + for (offs = 0; offs <= DFLL_MONITOR_DATA; offs += 4) { + if (offs == DFLL_OUTPUT_CFG) + val = dfll_i2c_readl(td, offs); + else + val = dfll_readl(td, offs); + seq_printf(s, "[0x%02x] = 0x%08x\n", offs, val); + } + + seq_puts(s, "\nI2C and INTR REGISTERS:\n"); + for (offs = DFLL_I2C_CFG; offs <= DFLL_I2C_STS; offs += 4) + seq_printf(s, "[0x%02x] = 0x%08x\n", offs, + dfll_i2c_readl(td, offs)); + for (offs = DFLL_INTR_STS; offs <= DFLL_INTR_EN; offs += 4) + seq_printf(s, "[0x%02x] = 0x%08x\n", offs, + dfll_i2c_readl(td, offs)); + + seq_puts(s, "\nINTEGRATED I2C CONTROLLER REGISTERS:\n"); + offs = DFLL_I2C_CLK_DIVISOR; + seq_printf(s, "[0x%02x] = 0x%08x\n", offs, + __raw_readl(td->i2c_controller_base + offs)); + + seq_puts(s, "\nLUT:\n"); + for (offs = 0; offs < 4 * MAX_DFLL_VOLTAGES; offs += 4) + seq_printf(s, "[0x%02x] = 0x%08x\n", offs, + __raw_readl(td->lut_base + offs)); + + return 0; +} + +static int attr_registers_open(struct inode *inode, struct file *file) +{ + return single_open(file, attr_registers_show, inode->i_private); +} + +static const struct file_operations attr_registers_fops = { + .open = attr_registers_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int dfll_debug_init(struct tegra_dfll *td) +{ + int ret; + + if (!td || (td->mode == DFLL_UNINITIALIZED)) + return 0; + + td->debugfs_dir = debugfs_create_dir("tegra_dfll_fcpu", NULL); + if (!td->debugfs_dir) + return -ENOMEM; + + ret = -ENOMEM; + + if (!debugfs_create_file("enable", S_IRUGO | S_IWUSR, + td->debugfs_dir, td, &enable_fops)) + goto err_out; + + if (!debugfs_create_file("rate", S_IRUGO, + td->debugfs_dir, td, &rate_fops)) + goto err_out; + + if (!debugfs_create_file("registers", S_IRUGO, + td->debugfs_dir, td, &attr_registers_fops)) + goto err_out; + + return 0; + +err_out: + debugfs_remove_recursive(td->debugfs_dir); + return ret; +} + +#endif /* CONFIG_DEBUG_FS */ + +/* + * DFLL initialization + */ + +/** + * dfll_set_default_params - program non-output related DFLL parameters + * @td: DFLL instance + * + * During DFLL driver initialization or resume from context loss, + * program parameters for the closed loop integrator, DVCO tuning, + * voltage droop control and monitor control. + */ +static void dfll_set_default_params(struct tegra_dfll *td) +{ + 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; + } + + 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); + + 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 + */ + +/** + * 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_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); + + 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; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(td->dev, "no control register resource\n"); + return -ENODEV; + } + + td->base = devm_ioremap(td->dev, mem->start, resource_size(mem)); + if (!td->base) { + dev_err(td->dev, "couldn't ioremap DFLL control registers\n"); + return -ENODEV; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!mem) { + dev_err(td->dev, "no i2c_base resource\n"); + return -ENODEV; + } + + td->i2c_base = devm_ioremap(td->dev, mem->start, resource_size(mem)); + if (!td->i2c_base) { + dev_err(td->dev, "couldn't ioremap i2c_base resource\n"); + return -ENODEV; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 2); + if (!mem) { + dev_err(td->dev, "no i2c_controller_base resource\n"); + return -ENODEV; + } + + td->i2c_controller_base = devm_ioremap(td->dev, mem->start, + resource_size(mem)); + if (!td->i2c_controller_base) { + dev_err(td->dev, + "couldn't ioremap i2c_controller_base resource\n"); + return -ENODEV; + } + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 3); + if (!mem) { + dev_err(td->dev, "no lut_base resource\n"); + return -ENODEV; + } + + td->lut_base = devm_ioremap(td->dev, mem->start, resource_size(mem)); + if (!td->lut_base) { + dev_err(td->dev, + "couldn't ioremap lut_base resource\n"); + return -ENODEV; + } + + ret = dfll_init_clks(td); + if (ret) { + dev_err(&pdev->dev, "DFLL clock init error\n"); + return ret; + } + + /* Enable the clocks and set the device up */ + ret = dfll_init(td); + if (ret) + return ret; + + ret = dfll_register_clk(td); + if (ret) { + dev_err(&pdev->dev, "DFLL clk registration failed\n"); + return ret; + } + +#ifdef CONFIG_DEBUG_FS + dfll_debug_init(td); +#endif + + return 0; +} +EXPORT_SYMBOL(tegra_dfll_register); + +/** + * tegra_dfll_unregister - release all of the DFLL driver resources for a device + * @pdev: DFLL platform_device * + * + * Unbind this driver from the DFLL hardware device represented by + * @pdev. The DFLL must be disabled for this to succeed. Returns 0 + * upon success or -EBUSY if the DFLL is still active. + */ +int tegra_dfll_unregister(struct platform_device *pdev) +{ + struct tegra_dfll *td = platform_get_drvdata(pdev); + + /* Try to prevent removal while the DFLL is active */ + if (td->mode != DFLL_DISABLED) { + dev_err(&pdev->dev, + "must disable DFLL before removing driver\n"); + return -EBUSY; + } + + debugfs_remove_recursive(td->debugfs_dir); + + dfll_unregister_clk(td); + pm_runtime_disable(&pdev->dev); + + clk_unprepare(td->ref_clk); + clk_unprepare(td->soc_clk); + clk_unprepare(td->i2c_clk); + + reset_control_assert(td->dvco_rst); + + return 0; +} +EXPORT_SYMBOL(tegra_dfll_unregister); |
