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linux_old1/drivers/clk/tegra/clk-dfll.c

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/*
* clk-dfll.c - Tegra DFLL clock source common code
*
* Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved.
*
* Aleksandr Frid <afrid@nvidia.com>
* Paul Walmsley <pwalmsley@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* This library is for the DVCO and DFLL IP blocks on the Tegra124
* SoC. These IP blocks together are also known at NVIDIA as
* "CL-DVFS". To try to avoid confusion, this code refers to them
* collectively as the "DFLL."
*
* The DFLL is a root clocksource which tolerates some amount of
* supply voltage noise. Tegra124 uses it to clock the fast CPU
* complex when the target CPU speed is above a particular rate. The
* DFLL can be operated in either open-loop mode or closed-loop mode.
* In open-loop mode, the DFLL generates an output clock appropriate
* to the supply voltage. In closed-loop mode, when configured with a
* target frequency, the DFLL minimizes supply voltage while
* delivering an average frequency equal to the target.
*
* Devices clocked by the DFLL must be able to tolerate frequency
* variation. In the case of the CPU, it's important to note that the
* CPU cycle time will vary. This has implications for
* performance-measurement code and any code that relies on the CPU
* cycle time to delay for a certain length of time.
*
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pm_opp.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/reset.h>
#include <linux/seq_file.h>
#include "clk-dfll.h"
/*
* DFLL control registers - access via dfll_{readl,writel}
*/
/* DFLL_CTRL: DFLL control register */
#define DFLL_CTRL 0x00
#define DFLL_CTRL_MODE_MASK 0x03
/* DFLL_CONFIG: DFLL sample rate control */
#define DFLL_CONFIG 0x04
#define DFLL_CONFIG_DIV_MASK 0xff
#define DFLL_CONFIG_DIV_PRESCALE 32
/* DFLL_PARAMS: tuning coefficients for closed loop integrator */
#define DFLL_PARAMS 0x08
#define DFLL_PARAMS_CG_SCALE (0x1 << 24)
#define DFLL_PARAMS_FORCE_MODE_SHIFT 22
#define DFLL_PARAMS_FORCE_MODE_MASK (0x3 << DFLL_PARAMS_FORCE_MODE_SHIFT)
#define DFLL_PARAMS_CF_PARAM_SHIFT 16
#define DFLL_PARAMS_CF_PARAM_MASK (0x3f << DFLL_PARAMS_CF_PARAM_SHIFT)
#define DFLL_PARAMS_CI_PARAM_SHIFT 8
#define DFLL_PARAMS_CI_PARAM_MASK (0x7 << DFLL_PARAMS_CI_PARAM_SHIFT)
#define DFLL_PARAMS_CG_PARAM_SHIFT 0
#define DFLL_PARAMS_CG_PARAM_MASK (0xff << DFLL_PARAMS_CG_PARAM_SHIFT)
/* DFLL_TUNE0: delay line configuration register 0 */
#define DFLL_TUNE0 0x0c
/* DFLL_TUNE1: delay line configuration register 1 */
#define DFLL_TUNE1 0x10
/* DFLL_FREQ_REQ: target DFLL frequency control */
#define DFLL_FREQ_REQ 0x14
#define DFLL_FREQ_REQ_FORCE_ENABLE (0x1 << 28)
#define DFLL_FREQ_REQ_FORCE_SHIFT 16
#define DFLL_FREQ_REQ_FORCE_MASK (0xfff << DFLL_FREQ_REQ_FORCE_SHIFT)
#define FORCE_MAX 2047
#define FORCE_MIN -2048
#define DFLL_FREQ_REQ_SCALE_SHIFT 8
#define DFLL_FREQ_REQ_SCALE_MASK (0xff << DFLL_FREQ_REQ_SCALE_SHIFT)
#define DFLL_FREQ_REQ_SCALE_MAX 256
#define DFLL_FREQ_REQ_FREQ_VALID (0x1 << 7)
#define DFLL_FREQ_REQ_MULT_SHIFT 0
#define DFLL_FREQ_REG_MULT_MASK (0x7f << DFLL_FREQ_REQ_MULT_SHIFT)
#define FREQ_MAX 127
/* DFLL_DROOP_CTRL: droop prevention control */
#define DFLL_DROOP_CTRL 0x1c
/* DFLL_OUTPUT_CFG: closed loop mode control registers */
/* NOTE: access via dfll_i2c_{readl,writel} */
#define DFLL_OUTPUT_CFG 0x20
#define DFLL_OUTPUT_CFG_I2C_ENABLE (0x1 << 30)
#define OUT_MASK 0x3f
#define DFLL_OUTPUT_CFG_SAFE_SHIFT 24
#define DFLL_OUTPUT_CFG_SAFE_MASK \
(OUT_MASK << DFLL_OUTPUT_CFG_SAFE_SHIFT)
#define DFLL_OUTPUT_CFG_MAX_SHIFT 16
#define DFLL_OUTPUT_CFG_MAX_MASK \
(OUT_MASK << DFLL_OUTPUT_CFG_MAX_SHIFT)
#define DFLL_OUTPUT_CFG_MIN_SHIFT 8
#define DFLL_OUTPUT_CFG_MIN_MASK \
(OUT_MASK << DFLL_OUTPUT_CFG_MIN_SHIFT)
#define DFLL_OUTPUT_CFG_PWM_DELTA (0x1 << 7)
#define DFLL_OUTPUT_CFG_PWM_ENABLE (0x1 << 6)
#define DFLL_OUTPUT_CFG_PWM_DIV_SHIFT 0
#define DFLL_OUTPUT_CFG_PWM_DIV_MASK \
(OUT_MASK << DFLL_OUTPUT_CFG_PWM_DIV_SHIFT)
/* DFLL_OUTPUT_FORCE: closed loop mode voltage forcing control */
#define DFLL_OUTPUT_FORCE 0x24
#define DFLL_OUTPUT_FORCE_ENABLE (0x1 << 6)
#define DFLL_OUTPUT_FORCE_VALUE_SHIFT 0
#define DFLL_OUTPUT_FORCE_VALUE_MASK \
(OUT_MASK << DFLL_OUTPUT_FORCE_VALUE_SHIFT)
/* DFLL_MONITOR_CTRL: internal monitor data source control */
#define DFLL_MONITOR_CTRL 0x28
#define DFLL_MONITOR_CTRL_FREQ 6
/* DFLL_MONITOR_DATA: internal monitor data output */
#define DFLL_MONITOR_DATA 0x2c
#define DFLL_MONITOR_DATA_NEW_MASK (0x1 << 16)
#define DFLL_MONITOR_DATA_VAL_SHIFT 0
#define DFLL_MONITOR_DATA_VAL_MASK (0xFFFF << DFLL_MONITOR_DATA_VAL_SHIFT)
/*
* I2C output control registers - access via dfll_i2c_{readl,writel}
*/
/* DFLL_I2C_CFG: I2C controller configuration register */
#define DFLL_I2C_CFG 0x40
#define DFLL_I2C_CFG_ARB_ENABLE (0x1 << 20)
#define DFLL_I2C_CFG_HS_CODE_SHIFT 16
#define DFLL_I2C_CFG_HS_CODE_MASK (0x7 << DFLL_I2C_CFG_HS_CODE_SHIFT)
#define DFLL_I2C_CFG_PACKET_ENABLE (0x1 << 15)
#define DFLL_I2C_CFG_SIZE_SHIFT 12
#define DFLL_I2C_CFG_SIZE_MASK (0x7 << DFLL_I2C_CFG_SIZE_SHIFT)
#define DFLL_I2C_CFG_SLAVE_ADDR_10 (0x1 << 10)
#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT 1
#define DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT 0
/* DFLL_I2C_VDD_REG_ADDR: PMIC I2C address for closed loop mode */
#define DFLL_I2C_VDD_REG_ADDR 0x44
/* DFLL_I2C_STS: I2C controller status */
#define DFLL_I2C_STS 0x48
#define DFLL_I2C_STS_I2C_LAST_SHIFT 1
#define DFLL_I2C_STS_I2C_REQ_PENDING 0x1
/* DFLL_INTR_STS: DFLL interrupt status register */
#define DFLL_INTR_STS 0x5c
/* DFLL_INTR_EN: DFLL interrupt enable register */
#define DFLL_INTR_EN 0x60
#define DFLL_INTR_MIN_MASK 0x1
#define DFLL_INTR_MAX_MASK 0x2
/*
* Integrated I2C controller registers - relative to td->i2c_controller_base
*/
/* DFLL_I2C_CLK_DIVISOR: I2C controller clock divisor */
#define DFLL_I2C_CLK_DIVISOR 0x6c
#define DFLL_I2C_CLK_DIVISOR_MASK 0xffff
#define DFLL_I2C_CLK_DIVISOR_FS_SHIFT 16
#define DFLL_I2C_CLK_DIVISOR_HS_SHIFT 0
#define DFLL_I2C_CLK_DIVISOR_PREDIV 8
#define DFLL_I2C_CLK_DIVISOR_HSMODE_PREDIV 12
/*
* Other constants
*/
/* MAX_DFLL_VOLTAGES: number of LUT entries in the DFLL IP block */
#define MAX_DFLL_VOLTAGES 33
/*
* REF_CLK_CYC_PER_DVCO_SAMPLE: the number of ref_clk cycles that the hardware
* integrates the DVCO counter over - used for debug rate monitoring and
* droop control
*/
#define REF_CLK_CYC_PER_DVCO_SAMPLE 4
/*
* REF_CLOCK_RATE: the DFLL reference clock rate currently supported by this
* driver, in Hz
*/
#define REF_CLOCK_RATE 51000000UL
#define DVCO_RATE_TO_MULT(rate, ref_rate) ((rate) / ((ref_rate) / 2))
#define MULT_TO_DVCO_RATE(mult, ref_rate) ((mult) * ((ref_rate) / 2))
/**
* enum dfll_ctrl_mode - DFLL hardware operating mode
* @DFLL_UNINITIALIZED: (uninitialized state - not in hardware bitfield)
* @DFLL_DISABLED: DFLL not generating an output clock
* @DFLL_OPEN_LOOP: DVCO running, but DFLL not adjusting voltage
* @DFLL_CLOSED_LOOP: DVCO running, and DFLL adjusting voltage to match
* the requested rate
*
* The integer corresponding to the last two states, minus one, is
* written to the DFLL hardware to change operating modes.
*/
enum dfll_ctrl_mode {
DFLL_UNINITIALIZED = 0,
DFLL_DISABLED = 1,
DFLL_OPEN_LOOP = 2,
DFLL_CLOSED_LOOP = 3,
};
/**
* enum dfll_tune_range - voltage range that the driver believes it's in
* @DFLL_TUNE_UNINITIALIZED: DFLL tuning not yet programmed
* @DFLL_TUNE_LOW: DFLL in the low-voltage range (or open-loop mode)
*
* Some DFLL tuning parameters may need to change depending on the
* DVCO's voltage; these states represent the ranges that the driver
* supports. These are software states; these values are never
* written into registers.
*/
enum dfll_tune_range {
DFLL_TUNE_UNINITIALIZED = 0,
DFLL_TUNE_LOW = 1,
};
/**
* struct dfll_rate_req - target DFLL rate request data
* @rate: target frequency, after the postscaling
* @dvco_target_rate: target frequency, after the postscaling
* @lut_index: LUT index at which voltage the dvco_target_rate will be reached
* @mult_bits: value to program to the MULT bits of the DFLL_FREQ_REQ register
* @scale_bits: value to program to the SCALE bits of the DFLL_FREQ_REQ register
*/
struct dfll_rate_req {
unsigned long rate;
unsigned long dvco_target_rate;
int lut_index;
u8 mult_bits;
u8 scale_bits;
};
struct tegra_dfll {
struct device *dev;
struct tegra_dfll_soc_data *soc;
void __iomem *base;
void __iomem *i2c_base;
void __iomem *i2c_controller_base;
void __iomem *lut_base;
struct regulator *vdd_reg;
struct clk *soc_clk;
struct clk *ref_clk;
struct clk *i2c_clk;
struct clk *dfll_clk;
struct reset_control *dvco_rst;
unsigned long ref_rate;
unsigned long i2c_clk_rate;
unsigned long dvco_rate_min;
enum dfll_ctrl_mode mode;
enum dfll_tune_range tune_range;
struct dentry *debugfs_dir;
struct clk_hw dfll_clk_hw;
const char *output_clock_name;
struct dfll_rate_req last_req;
unsigned long last_unrounded_rate;
/* Parameters from DT */
u32 droop_ctrl;
u32 sample_rate;
u32 force_mode;
u32 cf;
u32 ci;
u32 cg;
bool cg_scale;
/* I2C interface parameters */
u32 i2c_fs_rate;
u32 i2c_reg;
u32 i2c_slave_addr;
/* i2c_lut array entries are regulator framework selectors */
unsigned i2c_lut[MAX_DFLL_VOLTAGES];
int i2c_lut_size;
u8 lut_min, lut_max, lut_safe;
};
#define clk_hw_to_dfll(_hw) container_of(_hw, struct tegra_dfll, dfll_clk_hw)
/* mode_name: map numeric DFLL modes to names for friendly console messages */
static const char * const mode_name[] = {
[DFLL_UNINITIALIZED] = "uninitialized",
[DFLL_DISABLED] = "disabled",
[DFLL_OPEN_LOOP] = "open_loop",
[DFLL_CLOSED_LOOP] = "closed_loop",
};
/*
* Register accessors
*/
static inline u32 dfll_readl(struct tegra_dfll *td, u32 offs)
{
return __raw_readl(td->base + offs);
}
static inline void dfll_writel(struct tegra_dfll *td, u32 val, u32 offs)
{
WARN_ON(offs >= DFLL_I2C_CFG);
__raw_writel(val, td->base + offs);
}
static inline void dfll_wmb(struct tegra_dfll *td)
{
dfll_readl(td, DFLL_CTRL);
}
/* I2C output control registers - for addresses above DFLL_I2C_CFG */
static inline u32 dfll_i2c_readl(struct tegra_dfll *td, u32 offs)
{
return __raw_readl(td->i2c_base + offs);
}
static inline void dfll_i2c_writel(struct tegra_dfll *td, u32 val, u32 offs)
{
__raw_writel(val, td->i2c_base + offs);
}
static inline void dfll_i2c_wmb(struct tegra_dfll *td)
{
dfll_i2c_readl(td, DFLL_I2C_CFG);
}
/**
* dfll_is_running - is the DFLL currently generating a clock?
* @td: DFLL instance
*
* If the DFLL is currently generating an output clock signal, return
* true; otherwise return false.
*/
static bool dfll_is_running(struct tegra_dfll *td)
{
return td->mode >= DFLL_OPEN_LOOP;
}
/*
* Runtime PM suspend/resume callbacks
*/
/**
* tegra_dfll_runtime_resume - enable all clocks needed by the DFLL
* @dev: DFLL device *
*
* Enable all clocks needed by the DFLL. Assumes that clk_prepare()
* has already been called on all the clocks.
*
* XXX Should also handle context restore when returning from off.
*/
int tegra_dfll_runtime_resume(struct device *dev)
{
struct tegra_dfll *td = dev_get_drvdata(dev);
int ret;
ret = clk_enable(td->ref_clk);
if (ret) {
dev_err(dev, "could not enable ref clock: %d\n", ret);
return ret;
}
ret = clk_enable(td->soc_clk);
if (ret) {
dev_err(dev, "could not enable register clock: %d\n", ret);
clk_disable(td->ref_clk);
return ret;
}
ret = clk_enable(td->i2c_clk);
if (ret) {
dev_err(dev, "could not enable i2c clock: %d\n", ret);
clk_disable(td->soc_clk);
clk_disable(td->ref_clk);
return ret;
}
return 0;
}
EXPORT_SYMBOL(tegra_dfll_runtime_resume);
/**
* tegra_dfll_runtime_suspend - disable all clocks needed by the DFLL
* @dev: DFLL device *
*
* Disable all clocks needed by the DFLL. Assumes that other code
* will later call clk_unprepare().
*/
int tegra_dfll_runtime_suspend(struct device *dev)
{
struct tegra_dfll *td = dev_get_drvdata(dev);
clk_disable(td->ref_clk);
clk_disable(td->soc_clk);
clk_disable(td->i2c_clk);
return 0;
}
EXPORT_SYMBOL(tegra_dfll_runtime_suspend);
/*
* DFLL tuning operations (per-voltage-range tuning settings)
*/
/**
* dfll_tune_low - tune to DFLL and CPU settings valid for any voltage
* @td: DFLL instance
*
* Tune the DFLL oscillator parameters and the CPU clock shaper for
* the low-voltage range. These settings are valid for any voltage,
* but may not be optimal.
*/
static void dfll_tune_low(struct tegra_dfll *td)
{
td->tune_range = DFLL_TUNE_LOW;
dfll_writel(td, td->soc->tune0_low, DFLL_TUNE0);
dfll_writel(td, td->soc->tune1, DFLL_TUNE1);
dfll_wmb(td);
if (td->soc->set_clock_trimmers_low)
td->soc->set_clock_trimmers_low();
}
/*
* Output clock scaler helpers
*/
/**
* dfll_scale_dvco_rate - calculate scaled rate from the DVCO rate
* @scale_bits: clock scaler value (bits in the DFLL_FREQ_REQ_SCALE field)
* @dvco_rate: the DVCO rate
*
* Apply the same scaling formula that the DFLL hardware uses to scale
* the DVCO rate.
*/
static unsigned long dfll_scale_dvco_rate(int scale_bits,
unsigned long dvco_rate)
{
return (u64)dvco_rate * (scale_bits + 1) / DFLL_FREQ_REQ_SCALE_MAX;
}
/*
* DFLL mode switching
*/
/**
* dfll_set_mode - change the DFLL control mode
* @td: DFLL instance
* @mode: DFLL control mode (see enum dfll_ctrl_mode)
*
* Change the DFLL's operating mode between disabled, open-loop mode,
* and closed-loop mode, or vice versa.
*/
static void dfll_set_mode(struct tegra_dfll *td,
enum dfll_ctrl_mode mode)
{
td->mode = mode;
dfll_writel(td, mode - 1, DFLL_CTRL);
dfll_wmb(td);
}
/*
* DFLL-to-I2C controller interface
*/
/**
* dfll_i2c_set_output_enabled - enable/disable I2C PMIC voltage requests
* @td: DFLL instance
* @enable: whether to enable or disable the I2C voltage requests
*
* Set the master enable control for I2C control value updates. If disabled,
* then I2C control messages are inhibited, regardless of the DFLL mode.
*/
static int dfll_i2c_set_output_enabled(struct tegra_dfll *td, bool enable)
{
u32 val;
val = dfll_i2c_readl(td, DFLL_OUTPUT_CFG);
if (enable)
val |= DFLL_OUTPUT_CFG_I2C_ENABLE;
else
val &= ~DFLL_OUTPUT_CFG_I2C_ENABLE;
dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG);
dfll_i2c_wmb(td);
return 0;
}
/**
* dfll_load_lut - load the voltage lookup table
* @td: struct tegra_dfll *
*
* Load the voltage-to-PMIC register value lookup table into the DFLL
* IP block memory. Look-up tables can be loaded at any time.
*/
static void dfll_load_i2c_lut(struct tegra_dfll *td)
{
int i, lut_index;
u32 val;
for (i = 0; i < MAX_DFLL_VOLTAGES; i++) {
if (i < td->lut_min)
lut_index = td->lut_min;
else if (i > td->lut_max)
lut_index = td->lut_max;
else
lut_index = i;
val = regulator_list_hardware_vsel(td->vdd_reg,
td->i2c_lut[lut_index]);
__raw_writel(val, td->lut_base + i * 4);
}
dfll_i2c_wmb(td);
}
/**
* dfll_init_i2c_if - set up the DFLL's DFLL-I2C interface
* @td: DFLL instance
*
* During DFLL driver initialization, program the DFLL-I2C interface
* with the PMU slave address, vdd register offset, and transfer mode.
* This data is used by the DFLL to automatically construct I2C
* voltage-set commands, which are then passed to the DFLL's internal
* I2C controller.
*/
static void dfll_init_i2c_if(struct tegra_dfll *td)
{
u32 val;
if (td->i2c_slave_addr > 0x7f) {
val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_10BIT;
val |= DFLL_I2C_CFG_SLAVE_ADDR_10;
} else {
val = td->i2c_slave_addr << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT_7BIT;
}
val |= DFLL_I2C_CFG_SIZE_MASK;
val |= DFLL_I2C_CFG_ARB_ENABLE;
dfll_i2c_writel(td, val, DFLL_I2C_CFG);
dfll_i2c_writel(td, td->i2c_reg, DFLL_I2C_VDD_REG_ADDR);
val = DIV_ROUND_UP(td->i2c_clk_rate, td->i2c_fs_rate * 8);
BUG_ON(!val || (val > DFLL_I2C_CLK_DIVISOR_MASK));
val = (val - 1) << DFLL_I2C_CLK_DIVISOR_FS_SHIFT;
/* default hs divisor just in case */
val |= 1 << DFLL_I2C_CLK_DIVISOR_HS_SHIFT;
__raw_writel(val, td->i2c_controller_base + DFLL_I2C_CLK_DIVISOR);
dfll_i2c_wmb(td);
}
/**
* dfll_init_out_if - prepare DFLL-to-PMIC interface
* @td: DFLL instance
*
* During DFLL driver initialization or resume from context loss,
* disable the I2C command output to the PMIC, set safe voltage and
* output limits, and disable and clear limit interrupts.
*/
static void dfll_init_out_if(struct tegra_dfll *td)
{
u32 val;
td->lut_min = 0;
td->lut_max = td->i2c_lut_size - 1;
td->lut_safe = td->lut_min + 1;
dfll_i2c_writel(td, 0, DFLL_OUTPUT_CFG);
val = (td->lut_safe << DFLL_OUTPUT_CFG_SAFE_SHIFT) |
(td->lut_max << DFLL_OUTPUT_CFG_MAX_SHIFT) |
(td->lut_min << DFLL_OUTPUT_CFG_MIN_SHIFT);
dfll_i2c_writel(td, val, DFLL_OUTPUT_CFG);
dfll_i2c_wmb(td);
dfll_writel(td, 0, DFLL_OUTPUT_FORCE);
dfll_i2c_writel(td, 0, DFLL_INTR_EN);
dfll_i2c_writel(td, DFLL_INTR_MAX_MASK | DFLL_INTR_MIN_MASK,
DFLL_INTR_STS);
dfll_load_i2c_lut(td);
dfll_init_i2c_if(td);
}
/*
* Set/get the DFLL's targeted output clock rate
*/
/**
* find_lut_index_for_rate - determine I2C LUT index for given DFLL rate
* @td: DFLL instance
* @rate: clock rate
*
* Determines the index of a I2C LUT entry for a voltage that approximately
* produces the given DFLL clock rate. This is used when forcing a value
* to the integrator during rate changes. Returns -ENOENT if a suitable
* LUT index is not found.
*/
static int find_lut_index_for_rate(struct tegra_dfll *td, unsigned long rate)
{
struct dev_pm_opp *opp;
int i, uv;
rcu_read_lock();
opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
if (IS_ERR(opp)) {
rcu_read_unlock();
return PTR_ERR(opp);
}
uv = dev_pm_opp_get_voltage(opp);
rcu_read_unlock();
for (i = 0; i < td->i2c_lut_size; i++) {
if (regulator_list_voltage(td->vdd_reg, td->i2c_lut[i]) == uv)
return i;
}
return -ENOENT;
}
/**
* dfll_calculate_rate_request - calculate DFLL parameters for a given rate
* @td: DFLL instance
* @req: DFLL-rate-request structure
* @rate: the desired DFLL rate
*
* Populate the DFLL-rate-request record @req fields with the scale_bits
* and mult_bits fields, based on the target input rate. Returns 0 upon
* success, or -EINVAL if the requested rate in req->rate is too high
* or low for the DFLL to generate.
*/
static int dfll_calculate_rate_request(struct tegra_dfll *td,
struct dfll_rate_req *req,
unsigned long rate)
{
u32 val;
/*
* If requested rate is below the minimum DVCO rate, active the scaler.
* In the future the DVCO minimum voltage should be selected based on
* chip temperature and the actual minimum rate should be calibrated
* at runtime.
*/
req->scale_bits = DFLL_FREQ_REQ_SCALE_MAX - 1;
if (rate < td->dvco_rate_min) {
int scale;
scale = DIV_ROUND_CLOSEST(rate / 1000 * DFLL_FREQ_REQ_SCALE_MAX,
td->dvco_rate_min / 1000);
if (!scale) {
dev_err(td->dev, "%s: Rate %lu is too low\n",
__func__, rate);
return -EINVAL;
}
req->scale_bits = scale - 1;
rate = td->dvco_rate_min;
}
/* Convert requested rate into frequency request and scale settings */
val = DVCO_RATE_TO_MULT(rate, td->ref_rate);
if (val > FREQ_MAX) {
dev_err(td->dev, "%s: Rate %lu is above dfll range\n",
__func__, rate);
return -EINVAL;
}
req->mult_bits = val;
req->dvco_target_rate = MULT_TO_DVCO_RATE(req->mult_bits, td->ref_rate);
req->rate = dfll_scale_dvco_rate(req->scale_bits,
req->dvco_target_rate);
req->lut_index = find_lut_index_for_rate(td, req->dvco_target_rate);
if (req->lut_index < 0)
return req->lut_index;
return 0;
}
/**
* dfll_set_frequency_request - start the frequency change operation
* @td: DFLL instance
* @req: rate request structure
*
* Tell the DFLL to try to change its output frequency to the
* frequency represented by @req. DFLL must be in closed-loop mode.
*/
static void dfll_set_frequency_request(struct tegra_dfll *td,
struct dfll_rate_req *req)
{
u32 val = 0;
int force_val;
int coef = 128; /* FIXME: td->cg_scale? */;
force_val = (req->lut_index - td->lut_safe) * coef / td->cg;
force_val = clamp(force_val, FORCE_MIN, FORCE_MAX);
val |= req->mult_bits << DFLL_FREQ_REQ_MULT_SHIFT;
val |= req->scale_bits << DFLL_FREQ_REQ_SCALE_SHIFT;
val |= ((u32)force_val << DFLL_FREQ_REQ_FORCE_SHIFT) &
DFLL_FREQ_REQ_FORCE_MASK;
val |= DFLL_FREQ_REQ_FREQ_VALID | DFLL_FREQ_REQ_FORCE_ENABLE;
dfll_writel(td, val, DFLL_FREQ_REQ);
dfll_wmb(td);
}
/**
* tegra_dfll_request_rate - set the next rate for the DFLL to tune to
* @td: DFLL instance
* @rate: clock rate to target
*
* Convert the requested clock rate @rate into the DFLL control logic
* settings. In closed-loop mode, update new settings immediately to
* adjust DFLL output rate accordingly. Otherwise, just save them
* until the next switch to closed loop. Returns 0 upon success,
* -EPERM if the DFLL driver has not yet been initialized, or -EINVAL
* if @rate is outside the DFLL's tunable range.
*/
static int dfll_request_rate(struct tegra_dfll *td, unsigned long rate)
{
int ret;
struct dfll_rate_req req;
if (td->mode == DFLL_UNINITIALIZED) {
dev_err(td->dev, "%s: Cannot set DFLL rate in %s mode\n",
__func__, mode_name[td->mode]);
return -EPERM;
}
ret = dfll_calculate_rate_request(td, &req, rate);
if (ret)
return ret;
td->last_unrounded_rate = rate;
td->last_req = req;
if (td->mode == DFLL_CLOSED_LOOP)
dfll_set_frequency_request(td, &td->last_req);
return 0;
}
/*
* DFLL enable/disable & open-loop <-> closed-loop transitions
*/
/**
* dfll_disable - switch from open-loop mode to disabled mode
* @td: DFLL instance
*
* Switch from OPEN_LOOP state to DISABLED state. Returns 0 upon success
* or -EPERM if the DFLL is not currently in open-loop mode.
*/
static int dfll_disable(struct tegra_dfll *td)
{
if (td->mode != DFLL_OPEN_LOOP) {
dev_err(td->dev, "cannot disable DFLL in %s mode\n",
mode_name[td->mode]);
return -EINVAL;
}
dfll_set_mode(td, DFLL_DISABLED);
pm_runtime_put_sync(td->dev);
return 0;
}
/**
* dfll_enable - switch a disabled DFLL to open-loop mode
* @td: DFLL instance
*
* Switch from DISABLED state to OPEN_LOOP state. Returns 0 upon success
* or -EPERM if the DFLL is not currently disabled.
*/
static int dfll_enable(struct tegra_dfll *td)
{
if (td->mode != DFLL_DISABLED) {
dev_err(td->dev, "cannot enable DFLL in %s mode\n",
mode_name[td->mode]);
return -EPERM;
}
pm_runtime_get_sync(td->dev);
dfll_set_mode(td, DFLL_OPEN_LOOP);
return 0;
}
/**
* dfll_set_open_loop_config - prepare to switch to open-loop mode
* @td: DFLL instance
*
* Prepare to switch the DFLL to open-loop mode. This switches the
* DFLL to the low-voltage tuning range, ensures that I2C output
* forcing is disabled, and disables the output clock rate scaler.
* The DFLL's low-voltage tuning range parameters must be
* characterized to keep the downstream device stable at any DVCO
* input voltage. No return value.
*/
static void dfll_set_open_loop_config(struct tegra_dfll *td)
{
u32 val;
/* always tune low (safe) in open loop */
if (td->tune_range != DFLL_TUNE_LOW)
dfll_tune_low(td);
val = dfll_readl(td, DFLL_FREQ_REQ);
val |= DFLL_FREQ_REQ_SCALE_MASK;
val &= ~DFLL_FREQ_REQ_FORCE_ENABLE;
dfll_writel(td, val, DFLL_FREQ_REQ);
dfll_wmb(td);
}
/**
* tegra_dfll_lock - switch from open-loop to closed-loop mode
* @td: DFLL instance
*
* Switch from OPEN_LOOP state to CLOSED_LOOP state. Returns 0 upon success,
* -EINVAL if the DFLL's target rate hasn't been set yet, or -EPERM if the
* DFLL is not currently in open-loop mode.
*/
static int dfll_lock(struct tegra_dfll *td)
{
struct dfll_rate_req *req = &td->last_req;
switch (td->mode) {
case DFLL_CLOSED_LOOP:
return 0;
case DFLL_OPEN_LOOP:
if (req->rate == 0) {
dev_err(td->dev, "%s: Cannot lock DFLL at rate 0\n",
__func__);
return -EINVAL;
}
dfll_i2c_set_output_enabled(td, true);
dfll_set_mode(td, DFLL_CLOSED_LOOP);
dfll_set_frequency_request(td, req);
return 0;
default:
BUG_ON(td->mode > DFLL_CLOSED_LOOP);
dev_err(td->dev, "%s: Cannot lock DFLL in %s mode\n",
__func__, mode_name[td->mode]);
return -EPERM;
}
}
/**
* tegra_dfll_unlock - switch from closed-loop to open-loop mode
* @td: DFLL instance
*
* Switch from CLOSED_LOOP state to OPEN_LOOP state. Returns 0 upon success,
* or -EPERM if the DFLL is not currently in open-loop mode.
*/
static int dfll_unlock(struct tegra_dfll *td)
{
switch (td->mode) {
case DFLL_CLOSED_LOOP:
dfll_set_open_loop_config(td);
dfll_set_mode(td, DFLL_OPEN_LOOP);
dfll_i2c_set_output_enabled(td, false);
return 0;
case DFLL_OPEN_LOOP:
return 0;
default:
BUG_ON(td->mode > DFLL_CLOSED_LOOP);
dev_err(td->dev, "%s: Cannot unlock DFLL in %s mode\n",
__func__, mode_name[td->mode]);
return -EPERM;
}
}
/*
* Clock framework integration
*
* When the DFLL is being controlled by the CCF, always enter closed loop
* mode when the clk is enabled. This requires that a DFLL rate request
* has been set beforehand, which implies that a clk_set_rate() call is
* always required before a clk_enable().
*/
static int dfll_clk_is_enabled(struct clk_hw *hw)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
return dfll_is_running(td);
}
static int dfll_clk_enable(struct clk_hw *hw)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
int ret;
ret = dfll_enable(td);
if (ret)
return ret;
ret = dfll_lock(td);
if (ret)
dfll_disable(td);
return ret;
}
static void dfll_clk_disable(struct clk_hw *hw)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
int ret;
ret = dfll_unlock(td);
if (!ret)
dfll_disable(td);
}
static unsigned long dfll_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
return td->last_unrounded_rate;
}
/* Must use determine_rate since it allows for rates exceeding 2^31-1 */
static int dfll_clk_determine_rate(struct clk_hw *hw,
struct clk_rate_request *clk_req)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
struct dfll_rate_req req;
int ret;
ret = dfll_calculate_rate_request(td, &req, clk_req->rate);
if (ret)
return ret;
/*
* Don't set the rounded rate, since it doesn't really matter as
* the output rate will be voltage controlled anyway, and cpufreq
* freaks out if any rounding happens.
*/
return 0;
}
static int dfll_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct tegra_dfll *td = clk_hw_to_dfll(hw);
return dfll_request_rate(td, rate);
}
static const struct clk_ops dfll_clk_ops = {
.is_enabled = dfll_clk_is_enabled,
.enable = dfll_clk_enable,
.disable = dfll_clk_disable,
.recalc_rate = dfll_clk_recalc_rate,
.determine_rate = dfll_clk_determine_rate,
.set_rate = dfll_clk_set_rate,
};
static struct clk_init_data dfll_clk_init_data = {
.flags = CLK_IS_ROOT,
.ops = &dfll_clk_ops,
.num_parents = 0,
};
/**
* dfll_register_clk - register the DFLL output clock with the clock framework
* @td: DFLL instance
*
* Register the DFLL's output clock with the Linux clock framework and register
* the DFLL driver as an OF clock provider. Returns 0 upon success or -EINVAL
* or -ENOMEM upon failure.
*/
static int dfll_register_clk(struct tegra_dfll *td)
{
int ret;
dfll_clk_init_data.name = td->output_clock_name;
td->dfll_clk_hw.init = &dfll_clk_init_data;
td->dfll_clk = clk_register(td->dev, &td->dfll_clk_hw);
if (IS_ERR(td->dfll_clk)) {
dev_err(td->dev, "DFLL clock registration error\n");
return -EINVAL;
}
ret = of_clk_add_provider(td->dev->of_node, of_clk_src_simple_get,
td->dfll_clk);
if (ret) {
dev_err(td->dev, "of_clk_add_provider() failed\n");
clk_unregister(td->dfll_clk);
return ret;
}
return 0;
}
/**
* dfll_unregister_clk - unregister the DFLL output clock
* @td: DFLL instance
*
* Unregister the DFLL's output clock from the Linux clock framework
* and from clkdev. No return value.
*/
static void dfll_unregister_clk(struct tegra_dfll *td)
{
of_clk_del_provider(td->dev->of_node);
clk_unregister(td->dfll_clk);
td->dfll_clk = NULL;
}
/*
* Debugfs interface
*/
#ifdef CONFIG_DEBUG_FS
/*
* Monitor control
*/
/**
* dfll_calc_monitored_rate - convert DFLL_MONITOR_DATA_VAL rate into real freq
* @monitor_data: value read from the DFLL_MONITOR_DATA_VAL bitfield
* @ref_rate: DFLL reference clock rate
*
* Convert @monitor_data from DFLL_MONITOR_DATA_VAL units into cycles
* per second. Returns the converted value.
*/
static u64 dfll_calc_monitored_rate(u32 monitor_data,
unsigned long ref_rate)
{
return monitor_data * (ref_rate / REF_CLK_CYC_PER_DVCO_SAMPLE);
}
/**
* dfll_read_monitor_rate - return the DFLL's output rate from internal monitor
* @td: DFLL instance
*
* If the DFLL is enabled, return the last rate reported by the DFLL's
* internal monitoring hardware. This works in both open-loop and
* closed-loop mode, and takes the output scaler setting into account.
* Assumes that the monitor was programmed to monitor frequency before
* the sample period started. If the driver believes that the DFLL is
* currently uninitialized or disabled, it will return 0, since
* otherwise the DFLL monitor data register will return the last
* measured rate from when the DFLL was active.
*/
static u64 dfll_read_monitor_rate(struct tegra_dfll *td)
{
u32 v, s;
u64 pre_scaler_rate, post_scaler_rate;
if (!dfll_is_running(td))
return 0;
v = dfll_readl(td, DFLL_MONITOR_DATA);
v = (v & DFLL_MONITOR_DATA_VAL_MASK) >> DFLL_MONITOR_DATA_VAL_SHIFT;
pre_scaler_rate = dfll_calc_monitored_rate(v, td->ref_rate);
s = dfll_readl(td, DFLL_FREQ_REQ);
s = (s & DFLL_FREQ_REQ_SCALE_MASK) >> DFLL_FREQ_REQ_SCALE_SHIFT;
post_scaler_rate = dfll_scale_dvco_rate(s, pre_scaler_rate);
return post_scaler_rate;
}
static int attr_enable_get(void *data, u64 *val)
{
struct tegra_dfll *td = data;
*val = dfll_is_running(td);
return 0;
}
static int attr_enable_set(void *data, u64 val)
{
struct tegra_dfll *td = data;
return val ? dfll_enable(td) : dfll_disable(td);
}
DEFINE_SIMPLE_ATTRIBUTE(enable_fops, attr_enable_get, attr_enable_set,
"%llu\n");
static int attr_lock_get(void *data, u64 *val)
{
struct tegra_dfll *td = data;
*val = (td->mode == DFLL_CLOSED_LOOP);
return 0;
}
static int attr_lock_set(void *data, u64 val)
{
struct tegra_dfll *td = data;
return val ? dfll_lock(td) : dfll_unlock(td);
}
DEFINE_SIMPLE_ATTRIBUTE(lock_fops, attr_lock_get, attr_lock_set,
"%llu\n");
static int attr_rate_get(void *data, u64 *val)
{
struct tegra_dfll *td = data;
*val = dfll_read_monitor_rate(td);
return 0;
}
static int attr_rate_set(void *data, u64 val)
{
struct tegra_dfll *td = data;
return dfll_request_rate(td, val);
}
DEFINE_SIMPLE_ATTRIBUTE(rate_fops, attr_rate_get, attr_rate_set, "%llu\n");
static int attr_registers_show(struct seq_file *s, void *data)
{
u32 val, offs;
struct tegra_dfll *td = s->private;
seq_puts(s, "CONTROL REGISTERS:\n");
for (offs = 0; offs <= DFLL_MONITOR_DATA; offs += 4) {
if (offs == DFLL_OUTPUT_CFG)
val = dfll_i2c_readl(td, offs);
else
val = dfll_readl(td, offs);
seq_printf(s, "[0x%02x] = 0x%08x\n", offs, val);
}
seq_puts(s, "\nI2C and INTR REGISTERS:\n");
for (offs = DFLL_I2C_CFG; offs <= DFLL_I2C_STS; offs += 4)
seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
dfll_i2c_readl(td, offs));
for (offs = DFLL_INTR_STS; offs <= DFLL_INTR_EN; offs += 4)
seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
dfll_i2c_readl(td, offs));
seq_puts(s, "\nINTEGRATED I2C CONTROLLER REGISTERS:\n");
offs = DFLL_I2C_CLK_DIVISOR;
seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
__raw_readl(td->i2c_controller_base + offs));
seq_puts(s, "\nLUT:\n");
for (offs = 0; offs < 4 * MAX_DFLL_VOLTAGES; offs += 4)
seq_printf(s, "[0x%02x] = 0x%08x\n", offs,
__raw_readl(td->lut_base + offs));
return 0;
}
static int attr_registers_open(struct inode *inode, struct file *file)
{
return single_open(file, attr_registers_show, inode->i_private);
}
static const struct file_operations attr_registers_fops = {
.open = attr_registers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int dfll_debug_init(struct tegra_dfll *td)
{
int ret;
if (!td || (td->mode == DFLL_UNINITIALIZED))
return 0;
td->debugfs_dir = debugfs_create_dir("tegra_dfll_fcpu", NULL);
if (!td->debugfs_dir)
return -ENOMEM;
ret = -ENOMEM;
if (!debugfs_create_file("enable", S_IRUGO | S_IWUSR,
td->debugfs_dir, td, &enable_fops))
goto err_out;
if (!debugfs_create_file("lock", S_IRUGO,
td->debugfs_dir, td, &lock_fops))
goto err_out;
if (!debugfs_create_file("rate", S_IRUGO,
td->debugfs_dir, td, &rate_fops))
goto err_out;
if (!debugfs_create_file("registers", S_IRUGO,
td->debugfs_dir, td, &attr_registers_fops))
goto err_out;
return 0;
err_out:
debugfs_remove_recursive(td->debugfs_dir);
return ret;
}
#endif /* CONFIG_DEBUG_FS */
/*
* DFLL initialization
*/
/**
* dfll_set_default_params - program non-output related DFLL parameters
* @td: DFLL instance
*
* During DFLL driver initialization or resume from context loss,
* program parameters for the closed loop integrator, DVCO tuning,
* voltage droop control and monitor control.
*/
static void dfll_set_default_params(struct tegra_dfll *td)
{
u32 val;
val = DIV_ROUND_UP(td->ref_rate, td->sample_rate * 32);
BUG_ON(val > DFLL_CONFIG_DIV_MASK);
dfll_writel(td, val, DFLL_CONFIG);
val = (td->force_mode << DFLL_PARAMS_FORCE_MODE_SHIFT) |
(td->cf << DFLL_PARAMS_CF_PARAM_SHIFT) |
(td->ci << DFLL_PARAMS_CI_PARAM_SHIFT) |
(td->cg << DFLL_PARAMS_CG_PARAM_SHIFT) |
(td->cg_scale ? DFLL_PARAMS_CG_SCALE : 0);
dfll_writel(td, val, DFLL_PARAMS);
dfll_tune_low(td);
dfll_writel(td, td->droop_ctrl, DFLL_DROOP_CTRL);
dfll_writel(td, DFLL_MONITOR_CTRL_FREQ, DFLL_MONITOR_CTRL);
}
/**
* dfll_init_clks - clk_get() the DFLL source clocks
* @td: DFLL instance
*
* Call clk_get() on the DFLL source clocks and save the pointers for later
* use. Returns 0 upon success or error (see devm_clk_get) if one or more
* of the clocks couldn't be looked up.
*/
static int dfll_init_clks(struct tegra_dfll *td)
{
td->ref_clk = devm_clk_get(td->dev, "ref");
if (IS_ERR(td->ref_clk)) {
dev_err(td->dev, "missing ref clock\n");
return PTR_ERR(td->ref_clk);
}
td->soc_clk = devm_clk_get(td->dev, "soc");
if (IS_ERR(td->soc_clk)) {
dev_err(td->dev, "missing soc clock\n");
return PTR_ERR(td->soc_clk);
}
td->i2c_clk = devm_clk_get(td->dev, "i2c");
if (IS_ERR(td->i2c_clk)) {
dev_err(td->dev, "missing i2c clock\n");
return PTR_ERR(td->i2c_clk);
}
td->i2c_clk_rate = clk_get_rate(td->i2c_clk);
return 0;
}
/**
* dfll_init - Prepare the DFLL IP block for use
* @td: DFLL instance
*
* Do everything necessary to prepare the DFLL IP block for use. The
* DFLL will be left in DISABLED state. Called by dfll_probe().
* Returns 0 upon success, or passes along the error from whatever
* function returned it.
*/
static int dfll_init(struct tegra_dfll *td)
{
int ret;
td->ref_rate = clk_get_rate(td->ref_clk);
if (td->ref_rate != REF_CLOCK_RATE) {
dev_err(td->dev, "unexpected ref clk rate %lu, expecting %lu",
td->ref_rate, REF_CLOCK_RATE);
return -EINVAL;
}
reset_control_deassert(td->dvco_rst);
ret = clk_prepare(td->ref_clk);
if (ret) {
dev_err(td->dev, "failed to prepare ref_clk\n");
return ret;
}
ret = clk_prepare(td->soc_clk);
if (ret) {
dev_err(td->dev, "failed to prepare soc_clk\n");
goto di_err1;
}
ret = clk_prepare(td->i2c_clk);
if (ret) {
dev_err(td->dev, "failed to prepare i2c_clk\n");
goto di_err2;
}
td->last_unrounded_rate = 0;
pm_runtime_enable(td->dev);
pm_runtime_get_sync(td->dev);
dfll_set_mode(td, DFLL_DISABLED);
dfll_set_default_params(td);
if (td->soc->init_clock_trimmers)
td->soc->init_clock_trimmers();
dfll_set_open_loop_config(td);
dfll_init_out_if(td);
pm_runtime_put_sync(td->dev);
return 0;
di_err2:
clk_unprepare(td->soc_clk);
di_err1:
clk_unprepare(td->ref_clk);
reset_control_assert(td->dvco_rst);
return ret;
}
/*
* DT data fetch
*/
/*
* Find a PMIC voltage register-to-voltage mapping for the given voltage.
* An exact voltage match is required.
*/
static int find_vdd_map_entry_exact(struct tegra_dfll *td, int uV)
{
int i, n_voltages, reg_uV;
n_voltages = regulator_count_voltages(td->vdd_reg);
for (i = 0; i < n_voltages; i++) {
reg_uV = regulator_list_voltage(td->vdd_reg, i);
if (reg_uV < 0)
break;
if (uV == reg_uV)
return i;
}
dev_err(td->dev, "no voltage map entry for %d uV\n", uV);
return -EINVAL;
}
/*
* Find a PMIC voltage register-to-voltage mapping for the given voltage,
* rounding up to the closest supported voltage.
* */
static int find_vdd_map_entry_min(struct tegra_dfll *td, int uV)
{
int i, n_voltages, reg_uV;
n_voltages = regulator_count_voltages(td->vdd_reg);
for (i = 0; i < n_voltages; i++) {
reg_uV = regulator_list_voltage(td->vdd_reg, i);
if (reg_uV < 0)
break;
if (uV <= reg_uV)
return i;
}
dev_err(td->dev, "no voltage map entry rounding to %d uV\n", uV);
return -EINVAL;
}
/**
* dfll_build_i2c_lut - build the I2C voltage register lookup table
* @td: DFLL instance
*
* The DFLL hardware has 33 bytes of look-up table RAM that must be filled with
* PMIC voltage register values that span the entire DFLL operating range.
* This function builds the look-up table based on the OPP table provided by
* the soc-specific platform driver (td->soc->opp_dev) and the PMIC
* register-to-voltage mapping queried from the regulator framework.
*
* On success, fills in td->i2c_lut and returns 0, or -err on failure.
*/
static int dfll_build_i2c_lut(struct tegra_dfll *td)
{
int ret = -EINVAL;
int j, v, v_max, v_opp;
int selector;
unsigned long rate;
struct dev_pm_opp *opp;
int lut;
rcu_read_lock();
rate = ULONG_MAX;
opp = dev_pm_opp_find_freq_floor(td->soc->dev, &rate);
if (IS_ERR(opp)) {
dev_err(td->dev, "couldn't get vmax opp, empty opp table?\n");
goto out;
}
v_max = dev_pm_opp_get_voltage(opp);
v = td->soc->min_millivolts * 1000;
lut = find_vdd_map_entry_exact(td, v);
if (lut < 0)
goto out;
td->i2c_lut[0] = lut;
for (j = 1, rate = 0; ; rate++) {
opp = dev_pm_opp_find_freq_ceil(td->soc->dev, &rate);
if (IS_ERR(opp))
break;
v_opp = dev_pm_opp_get_voltage(opp);
if (v_opp <= td->soc->min_millivolts * 1000)
td->dvco_rate_min = dev_pm_opp_get_freq(opp);
for (;;) {
v += max(1, (v_max - v) / (MAX_DFLL_VOLTAGES - j));
if (v >= v_opp)
break;
selector = find_vdd_map_entry_min(td, v);
if (selector < 0)
goto out;
if (selector != td->i2c_lut[j - 1])
td->i2c_lut[j++] = selector;
}
v = (j == MAX_DFLL_VOLTAGES - 1) ? v_max : v_opp;
selector = find_vdd_map_entry_exact(td, v);
if (selector < 0)
goto out;
if (selector != td->i2c_lut[j - 1])
td->i2c_lut[j++] = selector;
if (v >= v_max)
break;
}
td->i2c_lut_size = j;
if (!td->dvco_rate_min)
dev_err(td->dev, "no opp above DFLL minimum voltage %d mV\n",
td->soc->min_millivolts);
else
ret = 0;
out:
rcu_read_unlock();
return ret;
}
/**
* read_dt_param - helper function for reading required parameters from the DT
* @td: DFLL instance
* @param: DT property name
* @dest: output pointer for the value read
*
* Read a required numeric parameter from the DFLL device node, or complain
* if the property doesn't exist. Returns a boolean indicating success for
* easy chaining of multiple calls to this function.
*/
static bool read_dt_param(struct tegra_dfll *td, const char *param, u32 *dest)
{
int err = of_property_read_u32(td->dev->of_node, param, dest);
if (err < 0) {
dev_err(td->dev, "failed to read DT parameter %s: %d\n",
param, err);
return false;
}
return true;
}
/**
* dfll_fetch_i2c_params - query PMIC I2C params from DT & regulator subsystem
* @td: DFLL instance
*
* Read all the parameters required for operation in I2C mode. The parameters
* can originate from the device tree or the regulator subsystem.
* Returns 0 on success or -err on failure.
*/
static int dfll_fetch_i2c_params(struct tegra_dfll *td)
{
struct regmap *regmap;
struct device *i2c_dev;
struct i2c_client *i2c_client;
int vsel_reg, vsel_mask;
int ret;
if (!read_dt_param(td, "nvidia,i2c-fs-rate", &td->i2c_fs_rate))
return -EINVAL;
regmap = regulator_get_regmap(td->vdd_reg);
i2c_dev = regmap_get_device(regmap);
i2c_client = to_i2c_client(i2c_dev);
td->i2c_slave_addr = i2c_client->addr;
ret = regulator_get_hardware_vsel_register(td->vdd_reg,
&vsel_reg,
&vsel_mask);
if (ret < 0) {
dev_err(td->dev,
"regulator unsuitable for DFLL I2C operation\n");
return -EINVAL;
}
td->i2c_reg = vsel_reg;
ret = dfll_build_i2c_lut(td);
if (ret) {
dev_err(td->dev, "couldn't build I2C LUT\n");
return ret;
}
return 0;
}
/**
* dfll_fetch_common_params - read DFLL parameters from the device tree
* @td: DFLL instance
*
* Read all the DT parameters that are common to both I2C and PWM operation.
* Returns 0 on success or -EINVAL on any failure.
*/
static int dfll_fetch_common_params(struct tegra_dfll *td)
{
bool ok = true;
ok &= read_dt_param(td, "nvidia,droop-ctrl", &td->droop_ctrl);
ok &= read_dt_param(td, "nvidia,sample-rate", &td->sample_rate);
ok &= read_dt_param(td, "nvidia,force-mode", &td->force_mode);
ok &= read_dt_param(td, "nvidia,cf", &td->cf);
ok &= read_dt_param(td, "nvidia,ci", &td->ci);
ok &= read_dt_param(td, "nvidia,cg", &td->cg);
td->cg_scale = of_property_read_bool(td->dev->of_node,
"nvidia,cg-scale");
if (of_property_read_string(td->dev->of_node, "clock-output-names",
&td->output_clock_name)) {
dev_err(td->dev, "missing clock-output-names property\n");
ok = false;
}
return ok ? 0 : -EINVAL;
}
/*
* API exported to per-SoC platform drivers
*/
/**
* tegra_dfll_register - probe a Tegra DFLL device
* @pdev: DFLL platform_device *
* @soc: Per-SoC integration and characterization data for this DFLL instance
*
* Probe and initialize a DFLL device instance. Intended to be called
* by a SoC-specific shim driver that passes in per-SoC integration
* and configuration data via @soc. Returns 0 on success or -err on failure.
*/
int tegra_dfll_register(struct platform_device *pdev,
struct tegra_dfll_soc_data *soc)
{
struct resource *mem;
struct tegra_dfll *td;
int ret;
if (!soc) {
dev_err(&pdev->dev, "no tegra_dfll_soc_data provided\n");
return -EINVAL;
}
td = devm_kzalloc(&pdev->dev, sizeof(*td), GFP_KERNEL);
if (!td)
return -ENOMEM;
td->dev = &pdev->dev;
platform_set_drvdata(pdev, td);
td->soc = soc;
td->vdd_reg = devm_regulator_get(td->dev, "vdd-cpu");
if (IS_ERR(td->vdd_reg)) {
dev_err(td->dev, "couldn't get vdd_cpu regulator\n");
return PTR_ERR(td->vdd_reg);
}
td->dvco_rst = devm_reset_control_get(td->dev, "dvco");
if (IS_ERR(td->dvco_rst)) {
dev_err(td->dev, "couldn't get dvco reset\n");
return PTR_ERR(td->dvco_rst);
}
ret = dfll_fetch_common_params(td);
if (ret) {
dev_err(td->dev, "couldn't parse device tree parameters\n");
return ret;
}
ret = dfll_fetch_i2c_params(td);
if (ret)
return ret;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem) {
dev_err(td->dev, "no control register resource\n");
return -ENODEV;
}
td->base = devm_ioremap(td->dev, mem->start, resource_size(mem));
if (!td->base) {
dev_err(td->dev, "couldn't ioremap DFLL control registers\n");
return -ENODEV;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!mem) {
dev_err(td->dev, "no i2c_base resource\n");
return -ENODEV;
}
td->i2c_base = devm_ioremap(td->dev, mem->start, resource_size(mem));
if (!td->i2c_base) {
dev_err(td->dev, "couldn't ioremap i2c_base resource\n");
return -ENODEV;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 2);
if (!mem) {
dev_err(td->dev, "no i2c_controller_base resource\n");
return -ENODEV;
}
td->i2c_controller_base = devm_ioremap(td->dev, mem->start,
resource_size(mem));
if (!td->i2c_controller_base) {
dev_err(td->dev,
"couldn't ioremap i2c_controller_base resource\n");
return -ENODEV;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 3);
if (!mem) {
dev_err(td->dev, "no lut_base resource\n");
return -ENODEV;
}
td->lut_base = devm_ioremap(td->dev, mem->start, resource_size(mem));
if (!td->lut_base) {
dev_err(td->dev,
"couldn't ioremap lut_base resource\n");
return -ENODEV;
}
ret = dfll_init_clks(td);
if (ret) {
dev_err(&pdev->dev, "DFLL clock init error\n");
return ret;
}
/* Enable the clocks and set the device up */
ret = dfll_init(td);
if (ret)
return ret;
ret = dfll_register_clk(td);
if (ret) {
dev_err(&pdev->dev, "DFLL clk registration failed\n");
return ret;
}
#ifdef CONFIG_DEBUG_FS
dfll_debug_init(td);
#endif
return 0;
}
EXPORT_SYMBOL(tegra_dfll_register);
/**
* tegra_dfll_unregister - release all of the DFLL driver resources for a device
* @pdev: DFLL platform_device *
*
* Unbind this driver from the DFLL hardware device represented by
* @pdev. The DFLL must be disabled for this to succeed. Returns 0
* upon success or -EBUSY if the DFLL is still active.
*/
int tegra_dfll_unregister(struct platform_device *pdev)
{
struct tegra_dfll *td = platform_get_drvdata(pdev);
/* Try to prevent removal while the DFLL is active */
if (td->mode != DFLL_DISABLED) {
dev_err(&pdev->dev,
"must disable DFLL before removing driver\n");
return -EBUSY;
}
debugfs_remove_recursive(td->debugfs_dir);
dfll_unregister_clk(td);
pm_runtime_disable(&pdev->dev);
clk_unprepare(td->ref_clk);
clk_unprepare(td->soc_clk);
clk_unprepare(td->i2c_clk);
reset_control_assert(td->dvco_rst);
return 0;
}
EXPORT_SYMBOL(tegra_dfll_unregister);
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