pwm-fsl-ftm.c
/*
* Freescale FlexTimer Module (FTM) PWM Driver
*
* Copyright 2012-2013 Freescale Semiconductor, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#define FTM_SC 0x00
#define FTM_SC_CLK_MASK_SHIFT 3
#define FTM_SC_CLK_MASK (3 << FTM_SC_CLK_MASK_SHIFT)
#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
#define FTM_SC_PS_MASK 0x7
#define FTM_CNT 0x04
#define FTM_MOD 0x08
#define FTM_CSC_BASE 0x0C
#define FTM_CSC_MSB BIT(5)
#define FTM_CSC_MSA BIT(4)
#define FTM_CSC_ELSB BIT(3)
#define FTM_CSC_ELSA BIT(2)
#define FTM_CSC(_channel) (FTM_CSC_BASE + ((_channel) * 8))
#define FTM_CV_BASE 0x10
#define FTM_CV(_channel) (FTM_CV_BASE + ((_channel) * 8))
#define FTM_CNTIN 0x4C
#define FTM_STATUS 0x50
#define FTM_MODE 0x54
#define FTM_MODE_FTMEN BIT(0)
#define FTM_MODE_INIT BIT(2)
#define FTM_MODE_PWMSYNC BIT(3)
#define FTM_SYNC 0x58
#define FTM_OUTINIT 0x5C
#define FTM_OUTMASK 0x60
#define FTM_COMBINE 0x64
#define FTM_DEADTIME 0x68
#define FTM_EXTTRIG 0x6C
#define FTM_POL 0x70
#define FTM_FMS 0x74
#define FTM_FILTER 0x78
#define FTM_FLTCTRL 0x7C
#define FTM_QDCTRL 0x80
#define FTM_CONF 0x84
#define FTM_FLTPOL 0x88
#define FTM_SYNCONF 0x8C
#define FTM_INVCTRL 0x90
#define FTM_SWOCTRL 0x94
#define FTM_PWMLOAD 0x98
enum fsl_pwm_clk {
FSL_PWM_CLK_SYS,
FSL_PWM_CLK_FIX,
FSL_PWM_CLK_EXT,
FSL_PWM_CLK_CNTEN,
FSL_PWM_CLK_MAX
};
struct fsl_pwm_chip {
struct pwm_chip chip;
struct mutex lock;
unsigned int cnt_select;
unsigned int clk_ps;
struct regmap *regmap;
int period_ns;
struct clk *clk[FSL_PWM_CLK_MAX];
};
static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
{
return container_of(chip, struct fsl_pwm_chip, chip);
}
static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
return clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
}
static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
}
static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
enum fsl_pwm_clk index)
{
unsigned long sys_rate, cnt_rate;
unsigned long long ratio;
sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
if (!sys_rate)
return -EINVAL;
cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
if (!cnt_rate)
return -EINVAL;
switch (index) {
case FSL_PWM_CLK_SYS:
fpc->clk_ps = 1;
break;
case FSL_PWM_CLK_FIX:
ratio = 2 * cnt_rate - 1;
do_div(ratio, sys_rate);
fpc->clk_ps = ratio;
break;
case FSL_PWM_CLK_EXT:
ratio = 4 * cnt_rate - 1;
do_div(ratio, sys_rate);
fpc->clk_ps = ratio;
break;
default:
return -EINVAL;
}
return 0;
}
static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
unsigned long period_ns)
{
unsigned long long c, c0;
c = clk_get_rate(fpc->clk[fpc->cnt_select]);
c = c * period_ns;
do_div(c, 1000000000UL);
do {
c0 = c;
do_div(c0, (1 << fpc->clk_ps));
if (c0 <= 0xFFFF)
return (unsigned long)c0;
} while (++fpc->clk_ps < 8);
return 0;
}
static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
unsigned long period_ns,
enum fsl_pwm_clk index)
{
int ret;
ret = fsl_pwm_calculate_default_ps(fpc, index);
if (ret) {
dev_err(fpc->chip.dev,
"failed to calculate default prescaler: %d\n",
ret);
return 0;
}
return fsl_pwm_calculate_cycles(fpc, period_ns);
}
static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
unsigned long period_ns)
{
enum fsl_pwm_clk m0, m1;
unsigned long fix_rate, ext_rate, cycles;
cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
FSL_PWM_CLK_SYS);
if (cycles) {
fpc->cnt_select = FSL_PWM_CLK_SYS;
return cycles;
}
fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
if (fix_rate > ext_rate) {
m0 = FSL_PWM_CLK_FIX;
m1 = FSL_PWM_CLK_EXT;
} else {
m0 = FSL_PWM_CLK_EXT;
m1 = FSL_PWM_CLK_FIX;
}
cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
if (cycles) {
fpc->cnt_select = m0;
return cycles;
}
fpc->cnt_select = m1;
return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
}
static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
unsigned long period_ns,
unsigned long duty_ns)
{
unsigned long long duty;
u32 val;
regmap_read(fpc->regmap, FTM_MOD, &val);
duty = (unsigned long long)duty_ns * (val + 1);
do_div(duty, period_ns);
return (unsigned long)duty;
}
static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
int duty_ns, int period_ns)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
u32 period, duty;
mutex_lock(&fpc->lock);
/*
* The Freescale FTM controller supports only a single period for
* all PWM channels, therefore incompatible changes need to be
* refused.
*/
if (fpc->period_ns && fpc->period_ns != period_ns) {
dev_err(fpc->chip.dev,
"conflicting period requested for PWM %u\n",
pwm->hwpwm);
mutex_unlock(&fpc->lock);
return -EBUSY;
}
if (!fpc->period_ns && duty_ns) {
period = fsl_pwm_calculate_period(fpc, period_ns);
if (!period) {
dev_err(fpc->chip.dev, "failed to calculate period\n");
mutex_unlock(&fpc->lock);
return -EINVAL;
}
regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
fpc->clk_ps);
regmap_write(fpc->regmap, FTM_MOD, period - 1);
fpc->period_ns = period_ns;
}
mutex_unlock(&fpc->lock);
duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
FTM_CSC_MSB | FTM_CSC_ELSB);
regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
return 0;
}
static int fsl_pwm_set_polarity(struct pwm_chip *chip,
struct pwm_device *pwm,
enum pwm_polarity polarity)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
u32 val;
regmap_read(fpc->regmap, FTM_POL, &val);
if (polarity == PWM_POLARITY_INVERSED)
val |= BIT(pwm->hwpwm);
else
val &= ~BIT(pwm->hwpwm);
regmap_write(fpc->regmap, FTM_POL, val);
return 0;
}
static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
{
int ret;
/* select counter clock source */
regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
FTM_SC_CLK(fpc->cnt_select));
ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
if (ret)
return ret;
ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
if (ret) {
clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
return ret;
}
return 0;
}
static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
int ret;
mutex_lock(&fpc->lock);
regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
ret = fsl_counter_clock_enable(fpc);
mutex_unlock(&fpc->lock);
return ret;
}
static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
u32 val;
mutex_lock(&fpc->lock);
regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
BIT(pwm->hwpwm));
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
regmap_read(fpc->regmap, FTM_OUTMASK, &val);
if ((val & 0xFF) == 0xFF)
fpc->period_ns = 0;
mutex_unlock(&fpc->lock);
}
static const struct pwm_ops fsl_pwm_ops = {
.request = fsl_pwm_request,
.free = fsl_pwm_free,
.config = fsl_pwm_config,
.set_polarity = fsl_pwm_set_polarity,
.enable = fsl_pwm_enable,
.disable = fsl_pwm_disable,
.owner = THIS_MODULE,
};
static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
{
int ret;
ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
if (ret)
return ret;
regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
return 0;
}
static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case FTM_CNT:
return true;
}
return false;
}
static const struct regmap_config fsl_pwm_regmap_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.max_register = FTM_PWMLOAD,
.volatile_reg = fsl_pwm_volatile_reg,
.cache_type = REGCACHE_FLAT,
};
static int fsl_pwm_probe(struct platform_device *pdev)
{
struct fsl_pwm_chip *fpc;
struct resource *res;
void __iomem *base;
int ret;
fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
if (!fpc)
return -ENOMEM;
mutex_init(&fpc->lock);
fpc->chip.dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
&fsl_pwm_regmap_config);
if (IS_ERR(fpc->regmap)) {
dev_err(&pdev->dev, "regmap init failed\n");
return PTR_ERR(fpc->regmap);
}
fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
}
fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
fpc->clk[FSL_PWM_CLK_CNTEN] =
devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
fpc->chip.ops = &fsl_pwm_ops;
fpc->chip.of_xlate = of_pwm_xlate_with_flags;
fpc->chip.of_pwm_n_cells = 3;
fpc->chip.base = -1;
fpc->chip.npwm = 8;
ret = pwmchip_add(&fpc->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, fpc);
return fsl_pwm_init(fpc);
}
static int fsl_pwm_remove(struct platform_device *pdev)
{
struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
return pwmchip_remove(&fpc->chip);
}
#ifdef CONFIG_PM_SLEEP
static int fsl_pwm_suspend(struct device *dev)
{
struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
int i;
regcache_cache_only(fpc->regmap, true);
regcache_mark_dirty(fpc->regmap);
for (i = 0; i < fpc->chip.npwm; i++) {
struct pwm_device *pwm = &fpc->chip.pwms[i];
if (!test_bit(PWMF_REQUESTED, &pwm->flags))
continue;
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_SYS]);
if (!pwm_is_enabled(pwm))
continue;
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
}
return 0;
}
static int fsl_pwm_resume(struct device *dev)
{
struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
int i;
for (i = 0; i < fpc->chip.npwm; i++) {
struct pwm_device *pwm = &fpc->chip.pwms[i];
if (!test_bit(PWMF_REQUESTED, &pwm->flags))
continue;
clk_prepare_enable(fpc->clk[FSL_PWM_CLK_SYS]);
if (!pwm_is_enabled(pwm))
continue;
clk_prepare_enable(fpc->clk[fpc->cnt_select]);
clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
}
/* restore all registers from cache */
regcache_cache_only(fpc->regmap, false);
regcache_sync(fpc->regmap);
return 0;
}
#endif
static const struct dev_pm_ops fsl_pwm_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
};
static const struct of_device_id fsl_pwm_dt_ids[] = {
{ .compatible = "fsl,vf610-ftm-pwm", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
static struct platform_driver fsl_pwm_driver = {
.driver = {
.name = "fsl-ftm-pwm",
.of_match_table = fsl_pwm_dt_ids,
.pm = &fsl_pwm_pm_ops,
},
.probe = fsl_pwm_probe,
.remove = fsl_pwm_remove,
};
module_platform_driver(fsl_pwm_driver);
MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
MODULE_ALIAS("platform:fsl-ftm-pwm");
MODULE_LICENSE("GPL");