linux/drivers/pwm/pwm-fsl-ftm.c
Uwe Kleine-König 5ba3eb4bb3 pwm: fsl-ftm: Simplify using devm_pwmchip_add()
This allows to drop the platform_driver's remove function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:41 +02:00

555 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Freescale FlexTimer Module (FTM) PWM Driver
*
* Copyright 2012-2013 Freescale Semiconductor, Inc.
*/
#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/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/fsl/ftm.h>
#define FTM_SC_CLK(c) (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
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_ftm_soc {
bool has_enable_bits;
};
struct fsl_pwm_periodcfg {
enum fsl_pwm_clk clk_select;
unsigned int clk_ps;
unsigned int mod_period;
};
struct fsl_pwm_chip {
struct pwm_chip chip;
struct mutex lock;
struct regmap *regmap;
/* This value is valid iff a pwm is running */
struct fsl_pwm_periodcfg period;
struct clk *ipg_clk;
struct clk *clk[FSL_PWM_CLK_MAX];
const struct fsl_ftm_soc *soc;
};
static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
{
return container_of(chip, struct fsl_pwm_chip, chip);
}
static void ftm_clear_write_protection(struct fsl_pwm_chip *fpc)
{
u32 val;
regmap_read(fpc->regmap, FTM_FMS, &val);
if (val & FTM_FMS_WPEN)
regmap_update_bits(fpc->regmap, FTM_MODE, FTM_MODE_WPDIS,
FTM_MODE_WPDIS);
}
static void ftm_set_write_protection(struct fsl_pwm_chip *fpc)
{
regmap_update_bits(fpc->regmap, FTM_FMS, FTM_FMS_WPEN, FTM_FMS_WPEN);
}
static bool fsl_pwm_periodcfg_are_equal(const struct fsl_pwm_periodcfg *a,
const struct fsl_pwm_periodcfg *b)
{
if (a->clk_select != b->clk_select)
return false;
if (a->clk_ps != b->clk_ps)
return false;
if (a->mod_period != b->mod_period)
return false;
return true;
}
static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
ret = clk_prepare_enable(fpc->ipg_clk);
if (!ret && fpc->soc->has_enable_bits) {
mutex_lock(&fpc->lock);
regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
BIT(pwm->hwpwm + 16));
mutex_unlock(&fpc->lock);
}
return ret;
}
static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
if (fpc->soc->has_enable_bits) {
mutex_lock(&fpc->lock);
regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
0);
mutex_unlock(&fpc->lock);
}
clk_disable_unprepare(fpc->ipg_clk);
}
static unsigned int fsl_pwm_ticks_to_ns(struct fsl_pwm_chip *fpc,
unsigned int ticks)
{
unsigned long rate;
unsigned long long exval;
rate = clk_get_rate(fpc->clk[fpc->period.clk_select]);
exval = ticks;
exval *= 1000000000UL;
do_div(exval, rate >> fpc->period.clk_ps);
return exval;
}
static bool fsl_pwm_calculate_period_clk(struct fsl_pwm_chip *fpc,
unsigned int period_ns,
enum fsl_pwm_clk index,
struct fsl_pwm_periodcfg *periodcfg
)
{
unsigned long long c;
unsigned int ps;
c = clk_get_rate(fpc->clk[index]);
c = c * period_ns;
do_div(c, 1000000000UL);
if (c == 0)
return false;
for (ps = 0; ps < 8 ; ++ps, c >>= 1) {
if (c <= 0x10000) {
periodcfg->clk_select = index;
periodcfg->clk_ps = ps;
periodcfg->mod_period = c - 1;
return true;
}
}
return false;
}
static bool fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
unsigned int period_ns,
struct fsl_pwm_periodcfg *periodcfg)
{
enum fsl_pwm_clk m0, m1;
unsigned long fix_rate, ext_rate;
bool ret;
ret = fsl_pwm_calculate_period_clk(fpc, period_ns, FSL_PWM_CLK_SYS,
periodcfg);
if (ret)
return true;
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;
}
ret = fsl_pwm_calculate_period_clk(fpc, period_ns, m0, periodcfg);
if (ret)
return true;
return fsl_pwm_calculate_period_clk(fpc, period_ns, m1, periodcfg);
}
static unsigned int fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
unsigned int duty_ns)
{
unsigned long long duty;
unsigned int period = fpc->period.mod_period + 1;
unsigned int period_ns = fsl_pwm_ticks_to_ns(fpc, period);
duty = (unsigned long long)duty_ns * period;
do_div(duty, period_ns);
return (unsigned int)duty;
}
static bool fsl_pwm_is_any_pwm_enabled(struct fsl_pwm_chip *fpc,
struct pwm_device *pwm)
{
u32 val;
regmap_read(fpc->regmap, FTM_OUTMASK, &val);
if (~val & 0xFF)
return true;
else
return false;
}
static bool fsl_pwm_is_other_pwm_enabled(struct fsl_pwm_chip *fpc,
struct pwm_device *pwm)
{
u32 val;
regmap_read(fpc->regmap, FTM_OUTMASK, &val);
if (~(val | BIT(pwm->hwpwm)) & 0xFF)
return true;
else
return false;
}
static int fsl_pwm_apply_config(struct fsl_pwm_chip *fpc,
struct pwm_device *pwm,
const struct pwm_state *newstate)
{
unsigned int duty;
u32 reg_polarity;
struct fsl_pwm_periodcfg periodcfg;
bool do_write_period = false;
if (!fsl_pwm_calculate_period(fpc, newstate->period, &periodcfg)) {
dev_err(fpc->chip.dev, "failed to calculate new period\n");
return -EINVAL;
}
if (!fsl_pwm_is_any_pwm_enabled(fpc, pwm))
do_write_period = true;
/*
* The Freescale FTM controller supports only a single period for
* all PWM channels, therefore verify if the newly computed period
* is different than the current period being used. In such case
* we allow to change the period only if no other pwm is running.
*/
else if (!fsl_pwm_periodcfg_are_equal(&fpc->period, &periodcfg)) {
if (fsl_pwm_is_other_pwm_enabled(fpc, pwm)) {
dev_err(fpc->chip.dev,
"Cannot change period for PWM %u, disable other PWMs first\n",
pwm->hwpwm);
return -EBUSY;
}
if (fpc->period.clk_select != periodcfg.clk_select) {
int ret;
enum fsl_pwm_clk oldclk = fpc->period.clk_select;
enum fsl_pwm_clk newclk = periodcfg.clk_select;
ret = clk_prepare_enable(fpc->clk[newclk]);
if (ret)
return ret;
clk_disable_unprepare(fpc->clk[oldclk]);
}
do_write_period = true;
}
ftm_clear_write_protection(fpc);
if (do_write_period) {
regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
FTM_SC_CLK(periodcfg.clk_select));
regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
periodcfg.clk_ps);
regmap_write(fpc->regmap, FTM_MOD, periodcfg.mod_period);
fpc->period = periodcfg;
}
duty = fsl_pwm_calculate_duty(fpc, newstate->duty_cycle);
regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
FTM_CSC_MSB | FTM_CSC_ELSB);
regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
reg_polarity = 0;
if (newstate->polarity == PWM_POLARITY_INVERSED)
reg_polarity = BIT(pwm->hwpwm);
regmap_update_bits(fpc->regmap, FTM_POL, BIT(pwm->hwpwm), reg_polarity);
ftm_set_write_protection(fpc);
return 0;
}
static int fsl_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
const struct pwm_state *newstate)
{
struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
struct pwm_state *oldstate = &pwm->state;
int ret = 0;
/*
* oldstate to newstate : action
*
* disabled to disabled : ignore
* enabled to disabled : disable
* enabled to enabled : update settings
* disabled to enabled : update settings + enable
*/
mutex_lock(&fpc->lock);
if (!newstate->enabled) {
if (oldstate->enabled) {
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->period.clk_select]);
}
goto end_mutex;
}
ret = fsl_pwm_apply_config(fpc, pwm, newstate);
if (ret)
goto end_mutex;
/* check if need to enable */
if (!oldstate->enabled) {
ret = clk_prepare_enable(fpc->clk[fpc->period.clk_select]);
if (ret)
goto end_mutex;
ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
if (ret) {
clk_disable_unprepare(fpc->clk[fpc->period.clk_select]);
goto end_mutex;
}
regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
0);
}
end_mutex:
mutex_unlock(&fpc->lock);
return ret;
}
static const struct pwm_ops fsl_pwm_ops = {
.request = fsl_pwm_request,
.free = fsl_pwm_free,
.apply = fsl_pwm_apply,
.owner = THIS_MODULE,
};
static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
{
int ret;
ret = clk_prepare_enable(fpc->ipg_clk);
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->ipg_clk);
return 0;
}
static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case FTM_FMS:
case FTM_MODE:
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;
void __iomem *base;
int ret;
fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
if (!fpc)
return -ENOMEM;
mutex_init(&fpc->lock);
fpc->soc = of_device_get_match_data(&pdev->dev);
fpc->chip.dev = &pdev->dev;
base = devm_platform_ioremap_resource(pdev, 0);
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]);
/*
* ipg_clk is the interface clock for the IP. If not provided, use the
* ftm_sys clock as the default.
*/
fpc->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(fpc->ipg_clk))
fpc->ipg_clk = fpc->clk[FSL_PWM_CLK_SYS];
fpc->chip.ops = &fsl_pwm_ops;
fpc->chip.npwm = 8;
ret = devm_pwmchip_add(&pdev->dev, &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);
}
#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->ipg_clk);
if (!pwm_is_enabled(pwm))
continue;
clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
clk_disable_unprepare(fpc->clk[fpc->period.clk_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->ipg_clk);
if (!pwm_is_enabled(pwm))
continue;
clk_prepare_enable(fpc->clk[fpc->period.clk_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 fsl_ftm_soc vf610_ftm_pwm = {
.has_enable_bits = false,
};
static const struct fsl_ftm_soc imx8qm_ftm_pwm = {
.has_enable_bits = true,
};
static const struct of_device_id fsl_pwm_dt_ids[] = {
{ .compatible = "fsl,vf610-ftm-pwm", .data = &vf610_ftm_pwm },
{ .compatible = "fsl,imx8qm-ftm-pwm", .data = &imx8qm_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,
};
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");