Hi Tuomas, A bunch of small nit picks from me. On Wed, Aug 20, 2014 at 2:04 PM, Tuomas Tynkkynen <ttynkkynen@xxxxxxxxxx> wrote: > Add shared code to support the Tegra DFLL clocksource in open-loop > mode. This root clocksource is present on the Tegra124 SoCs. The > DFLL is the intended primary clock source for the fast CPU cluster. > > This code is very closely based on a patch by Paul Walmsley from > December (http://comments.gmane.org/gmane.linux.ports.tegra/15273), > which in turn comes from the internal driver by originally created > by Aleksandr Frid <afrid@xxxxxxxxxx>. > > Subsequent patches will add support for closed loop mode and drivers > for the Tegra124 fast CPU cluster DFLL devices, which rely on this > code. > > Signed-off-by: Paul Walmsley <pwalmsley@xxxxxxxxxx> > Signed-off-by: Tuomas Tynkkynen <ttynkkynen@xxxxxxxxxx> > --- > v4: Use correct accessor function for the DFLL_OUTPUT_CFG register > v3: Fix incorrect order of arguments to dfll_scale_dvco_rate call > --- > drivers/clk/tegra/Makefile | 1 + > drivers/clk/tegra/clk-dfll.c | 1090 ++++++++++++++++++++++++++++++++++++++++++ > drivers/clk/tegra/clk-dfll.h | 55 +++ > 3 files changed, 1146 insertions(+) > create mode 100644 drivers/clk/tegra/clk-dfll.c > create mode 100644 drivers/clk/tegra/clk-dfll.h > > diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile > index f7dfb72..47320ca 100644 > --- a/drivers/clk/tegra/Makefile > +++ b/drivers/clk/tegra/Makefile > @@ -1,5 +1,6 @@ > obj-y += clk.o > obj-y += clk-audio-sync.o > +obj-y += clk-dfll.o > obj-y += clk-divider.o > obj-y += clk-periph.o > obj-y += clk-periph-gate.o > diff --git a/drivers/clk/tegra/clk-dfll.c b/drivers/clk/tegra/clk-dfll.c > new file mode 100644 > index 0000000..fb21018 > --- /dev/null > +++ b/drivers/clk/tegra/clk-dfll.c > @@ -0,0 +1,1090 @@ > +/* > + * clk-dfll.c - Tegra DFLL clock source common code > + * > + * Copyright (C) 2012-2014 NVIDIA Corporation. All rights reserved. > + * > + * Aleksandr Frid <afrid@xxxxxxxxxx> > + * Paul Walmsley <pwalmsley@xxxxxxxxxx> > + * > + * 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/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 Missing a tab? > +#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 > +#define DFLL_I2C_CFG_SLAVE_ADDR_MASK (0x3ff << DFLL_I2C_CFG_SLAVE_ADDR_SHIFT) DFLL_I2C_CFG_SLAVE_ADDR_SHIFT isn't defined, and DFLL_I2C_CFG_SLAVE_ADDR_MASK does the wrong thing for 7-bit shift. > + > +/* DFLL_I2C_VDD_REG_ADDR: PMIC I2C address for closed loop mode */ > +#define DFLL_I2C_VDD_REG_ADDR 0x44 Missing a tab? I think some of the above section also might not be lined up with the rest. > + > +/* 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; > + 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->i2c_clk); > + if (ret) { > + dev_err(dev, "could not enable I2C clock: %d\n", ret); > + return 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); > + 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->soc_clk); > + clk_disable(td->ref_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 > + * upon failure. > + */ Can also return -ENOMEM from of_clk_add_provider. > +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"); > + goto out_unregister_clk; > + } > + > + return 0; > + > +out_unregister_clk: > + clk_unregister(td->dfll_clk); > + > + return ret; > +} > + > +/** > + * 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 -ENODEV if one or more of the clocks > + * couldn't be looked up. The comment about -ENODEV doesn't seem accurate. > + */ > +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); The ordering of the various operations which operate on all the clocks seem to change between each function. > + > + 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; > + } > + > + if (td->soc->deassert_dvco_reset) > + td->soc->deassert_dvco_reset(); > + > + ret = clk_prepare(td->i2c_clk); > + if (ret) { > + dev_err(td->dev, "failed to prepare i2c_clk\n"); > + return ret; > + } > + > + ret = clk_prepare(td->ref_clk); > + if (ret) { > + dev_err(td->dev, "failed to prepare ref_clk\n"); > + goto di_err1; > + } > + > + ret = clk_prepare(td->soc_clk); > + if (ret) { > + dev_err(td->dev, "failed to prepare soc_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->ref_clk); > +di_err1: > + clk_unprepare(td->i2c_clk); > + > + if (td->soc->assert_dvco_reset) > + td->soc->assert_dvco_reset(); > + > + 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; > + > + td = devm_kzalloc(&pdev->dev, sizeof(*td), GFP_KERNEL); > + if (!td) > + return -ENOMEM; > + td->dev = &pdev->dev; > + platform_set_drvdata(pdev, td); > + > + if (!soc) { > + dev_err(td->dev, "no tegra_dfll_soc_data provided\n"); > + return -EINVAL; > + } Could check this parameter first to avoid a potentially unnecessary allocation. > + 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); > + } > + > + 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->soc_clk); > + clk_unprepare(td->ref_clk); > + clk_unprepare(td->i2c_clk); > + > + if (td->soc->assert_dvco_reset) > + td->soc->assert_dvco_reset(); > + > + return 0; > +} > +EXPORT_SYMBOL(tegra_dfll_unregister); > diff --git a/drivers/clk/tegra/clk-dfll.h b/drivers/clk/tegra/clk-dfll.h > new file mode 100644 > index 0000000..fbf90c4 > --- /dev/null > +++ b/drivers/clk/tegra/clk-dfll.h > @@ -0,0 +1,55 @@ > +/* > + * clk-dfll.h - prototypes and macros for the Tegra DFLL clocksource driver > + * Copyright (C) 2013 NVIDIA Corporation. All rights reserved. > + * > + * Aleksandr Frid <afrid@xxxxxxxxxx> > + * Paul Walmsley <pwalmsley@xxxxxxxxxx> > + * > + * 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. > + */ > + > +#ifndef __DRIVERS_CLK_TEGRA_CLK_DFLL_H > +#define __DRIVERS_CLK_TEGRA_CLK_DFLL_H > + > +#include <linux/platform_device.h> > +#include <linux/types.h> > + > +/** > + * struct tegra_dfll_soc - SoC-specific hooks/integration for the DFLL driver Should be tegra_dfll_soc_data. > + * @opp_dev: struct device * that holds the OPP table for the DFLL > + * @min_millivolts: minimum voltage (in mV) that the DFLL can operate > + * @tune0_low: DFLL tuning register 0 (low voltage range) > + * @tune0_high: DFLL tuning register 0 (high voltage range) > + * @tune1: DFLL tuning register 1 > + * @assert_dvco_reset: fn ptr to place the DVCO in reset > + * @deassert_dvco_reset: fn ptr to release the DVCO reset > + * @set_clock_trimmers_high: fn ptr to tune clock trimmers for high voltage > + * @set_clock_trimmers_low: fn ptr to tune clock trimmers for low voltage > + */ > +struct tegra_dfll_soc_data { > + struct device *opp_dev; > + unsigned int min_millivolts; > + u32 tune0_low; > + u32 tune0_high; > + u32 tune1; > + void (*assert_dvco_reset)(void); > + void (*deassert_dvco_reset)(void); > + void (*init_clock_trimmers)(void); > + void (*set_clock_trimmers_high)(void); > + void (*set_clock_trimmers_low)(void); > +}; > + > +int tegra_dfll_register(struct platform_device *pdev, > + struct tegra_dfll_soc_data *soc); > +int tegra_dfll_unregister(struct platform_device *pdev); > +int tegra_dfll_runtime_suspend(struct device *dev); > +int tegra_dfll_runtime_resume(struct device *dev); > + > +#endif /* __DRIVERS_CLK_TEGRA_CLK_DFLL_H */ > -- > 1.8.1.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
