[linux.git] / drivers / pwm / pwm-lpc18xx-sct.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * NXP LPC18xx State Configurable Timer - Pulse Width Modulator driver
 *
 * Copyright (c) 2015 Ariel D'Alessandro <[email protected]>
 *
 * Notes
 * =====
 * NXP LPC18xx provides a State Configurable Timer (SCT) which can be configured
 * as a Pulse Width Modulator.
 *
 * SCT supports 16 outputs, 16 events and 16 registers. Each event will be
 * triggered when its related register matches the SCT counter value, and it
 * will set or clear a selected output.
 *
 * One of the events is preselected to generate the period, thus the maximum
 * number of simultaneous channels is limited to 15. Notice that period is
 * global to all the channels, thus PWM driver will refuse setting different
 * values to it, unless there's only one channel requested.
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>

/* LPC18xx SCT registers */
#define LPC18XX_PWM_CONFIG		0x000
#define LPC18XX_PWM_CONFIG_UNIFY	BIT(0)
#define LPC18XX_PWM_CONFIG_NORELOAD	BIT(7)

#define LPC18XX_PWM_CTRL		0x004
#define LPC18XX_PWM_CTRL_HALT		BIT(2)
#define LPC18XX_PWM_BIDIR		BIT(4)
#define LPC18XX_PWM_PRE_SHIFT		5
#define LPC18XX_PWM_PRE_MASK		(0xff << LPC18XX_PWM_PRE_SHIFT)
#define LPC18XX_PWM_PRE(x)		(x << LPC18XX_PWM_PRE_SHIFT)

#define LPC18XX_PWM_LIMIT		0x008

#define LPC18XX_PWM_RES_BASE		0x058
#define LPC18XX_PWM_RES_SHIFT(_ch)	(_ch * 2)
#define LPC18XX_PWM_RES(_ch, _action)	(_action << LPC18XX_PWM_RES_SHIFT(_ch))
#define LPC18XX_PWM_RES_MASK(_ch)	(0x3 << LPC18XX_PWM_RES_SHIFT(_ch))

#define LPC18XX_PWM_MATCH_BASE		0x100
#define LPC18XX_PWM_MATCH(_ch)		(LPC18XX_PWM_MATCH_BASE + _ch * 4)

#define LPC18XX_PWM_MATCHREL_BASE	0x200
#define LPC18XX_PWM_MATCHREL(_ch)	(LPC18XX_PWM_MATCHREL_BASE + _ch * 4)

#define LPC18XX_PWM_EVSTATEMSK_BASE	0x300
#define LPC18XX_PWM_EVSTATEMSK(_ch)	(LPC18XX_PWM_EVSTATEMSK_BASE + _ch * 8)
#define LPC18XX_PWM_EVSTATEMSK_ALL	0xffffffff

#define LPC18XX_PWM_EVCTRL_BASE		0x304
#define LPC18XX_PWM_EVCTRL(_ev)		(LPC18XX_PWM_EVCTRL_BASE + _ev * 8)

#define LPC18XX_PWM_EVCTRL_MATCH(_ch)	_ch

#define LPC18XX_PWM_EVCTRL_COMB_SHIFT	12
#define LPC18XX_PWM_EVCTRL_COMB_MATCH	(0x1 << LPC18XX_PWM_EVCTRL_COMB_SHIFT)

#define LPC18XX_PWM_OUTPUTSET_BASE	0x500
#define LPC18XX_PWM_OUTPUTSET(_ch)	(LPC18XX_PWM_OUTPUTSET_BASE + _ch * 8)

#define LPC18XX_PWM_OUTPUTCL_BASE	0x504
#define LPC18XX_PWM_OUTPUTCL(_ch)	(LPC18XX_PWM_OUTPUTCL_BASE + _ch * 8)

/* LPC18xx SCT unified counter */
#define LPC18XX_PWM_TIMER_MAX		0xffffffff

/* LPC18xx SCT events */
#define LPC18XX_PWM_EVENT_PERIOD	0
#define LPC18XX_PWM_EVENT_MAX		16

#define LPC18XX_NUM_PWMS		16

/* SCT conflict resolution */
enum lpc18xx_pwm_res_action {
	LPC18XX_PWM_RES_NONE,
	LPC18XX_PWM_RES_SET,
	LPC18XX_PWM_RES_CLEAR,
	LPC18XX_PWM_RES_TOGGLE,
};

struct lpc18xx_pwm_data {
	unsigned int duty_event;
};

struct lpc18xx_pwm_chip {
	struct device *dev;
	struct pwm_chip chip;
	void __iomem *base;
	struct clk *pwm_clk;
	unsigned long clk_rate;
	unsigned int period_ns;
	unsigned int min_period_ns;
	u64 max_period_ns;
	unsigned int period_event;
	unsigned long event_map;
	struct mutex res_lock;
	struct mutex period_lock;
	struct lpc18xx_pwm_data channeldata[LPC18XX_NUM_PWMS];
};

static inline struct lpc18xx_pwm_chip *
to_lpc18xx_pwm_chip(struct pwm_chip *chip)
{
	return container_of(chip, struct lpc18xx_pwm_chip, chip);
}

static inline void lpc18xx_pwm_writel(struct lpc18xx_pwm_chip *lpc18xx_pwm,
				      u32 reg, u32 val)
{
	writel(val, lpc18xx_pwm->base + reg);
}

static inline u32 lpc18xx_pwm_readl(struct lpc18xx_pwm_chip *lpc18xx_pwm,
				    u32 reg)
{
	return readl(lpc18xx_pwm->base + reg);
}

static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
					 struct pwm_device *pwm,
					 enum lpc18xx_pwm_res_action action)
{
	u32 val;

	mutex_lock(&lpc18xx_pwm->res_lock);

	/*
	 * Simultaneous set and clear may happen on an output, that is the case
	 * when duty_ns == period_ns. LPC18xx SCT allows to set a conflict
	 * resolution action to be taken in such a case.
	 */
	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_RES_BASE);
	val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);
	val |= LPC18XX_PWM_RES(pwm->hwpwm, action);
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_RES_BASE, val);

	mutex_unlock(&lpc18xx_pwm->res_lock);
}

static void lpc18xx_pwm_config_period(struct pwm_chip *chip, u64 period_ns)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	u32 val;

	/*
	 * With clk_rate < NSEC_PER_SEC this cannot overflow.
	 * With period_ns < max_period_ns this also fits into an u32.
	 * As period_ns >= min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, lpc18xx_pwm->clk_rate);
	 * we have val >= 1.
	 */
	val = mul_u64_u64_div_u64(period_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),
			   val - 1);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),
			   val - 1);
}

static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
				    struct pwm_device *pwm, u64 duty_ns)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
	u32 val;

	/*
	 * With clk_rate < NSEC_PER_SEC this cannot overflow.
	 * With duty_ns <= period_ns < max_period_ns this also fits into an u32.
	 */
	val = mul_u64_u64_div_u64(duty_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),
			   val);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),
			   val);
}

static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			      int duty_ns, int period_ns)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	int requested_events, i;

	if (period_ns < lpc18xx_pwm->min_period_ns ||
	    period_ns > lpc18xx_pwm->max_period_ns) {
		dev_err(chip->dev, "period %d not in range\n", period_ns);
		return -ERANGE;
	}

	mutex_lock(&lpc18xx_pwm->period_lock);

	requested_events = bitmap_weight(&lpc18xx_pwm->event_map,
					 LPC18XX_PWM_EVENT_MAX);

	/*
	 * The PWM supports only a single period for all PWM channels.
	 * Once the period is set, it can only be changed if no more than one
	 * channel is requested at that moment.
	 */
	if (requested_events > 2 && lpc18xx_pwm->period_ns != period_ns &&
	    lpc18xx_pwm->period_ns) {
		dev_err(chip->dev, "conflicting period requested for PWM %u\n",
			pwm->hwpwm);
		mutex_unlock(&lpc18xx_pwm->period_lock);
		return -EBUSY;
	}

	if ((requested_events <= 2 && lpc18xx_pwm->period_ns != period_ns) ||
	    !lpc18xx_pwm->period_ns) {
		lpc18xx_pwm->period_ns = period_ns;
		for (i = 0; i < chip->npwm; i++)
			pwm_set_period(&chip->pwms[i], period_ns);
		lpc18xx_pwm_config_period(chip, period_ns);
	}

	mutex_unlock(&lpc18xx_pwm->period_lock);

	lpc18xx_pwm_config_duty(chip, pwm, duty_ns);

	return 0;
}

static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm, enum pwm_polarity polarity)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
	enum lpc18xx_pwm_res_action res_action;
	unsigned int set_event, clear_event;

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event),
			   LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_data->duty_event) |
			   LPC18XX_PWM_EVCTRL_COMB_MATCH);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
			   LPC18XX_PWM_EVSTATEMSK_ALL);

	if (polarity == PWM_POLARITY_NORMAL) {
		set_event = lpc18xx_pwm->period_event;
		clear_event = lpc18xx_data->duty_event;
		res_action = LPC18XX_PWM_RES_SET;
	} else {
		set_event = lpc18xx_data->duty_event;
		clear_event = lpc18xx_pwm->period_event;
		res_action = LPC18XX_PWM_RES_CLEAR;
	}

	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm),
			   BIT(set_event));
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm),
			   BIT(clear_event));
	lpc18xx_pwm_set_conflict_res(lpc18xx_pwm, pwm, res_action);

	return 0;
}

static void lpc18xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm), 0);
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm), 0);
}

static int lpc18xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
	unsigned long event;

	event = find_first_zero_bit(&lpc18xx_pwm->event_map,
				    LPC18XX_PWM_EVENT_MAX);

	if (event >= LPC18XX_PWM_EVENT_MAX) {
		dev_err(lpc18xx_pwm->dev,
			"maximum number of simultaneous channels reached\n");
		return -EBUSY;
	}

	set_bit(event, &lpc18xx_pwm->event_map);
	lpc18xx_data->duty_event = event;

	return 0;
}

static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];

	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
}

static int lpc18xx_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
			     const struct pwm_state *state)
{
	int err;
	bool enabled = pwm->state.enabled;

	if (state->polarity != pwm->state.polarity && pwm->state.enabled) {
		lpc18xx_pwm_disable(chip, pwm);
		enabled = false;
	}

	if (!state->enabled) {
		if (enabled)
			lpc18xx_pwm_disable(chip, pwm);

		return 0;
	}

	err = lpc18xx_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
	if (err)
		return err;

	if (!enabled)
		err = lpc18xx_pwm_enable(chip, pwm, state->polarity);

	return err;
}
static const struct pwm_ops lpc18xx_pwm_ops = {
	.apply = lpc18xx_pwm_apply,
	.request = lpc18xx_pwm_request,
	.free = lpc18xx_pwm_free,
	.owner = THIS_MODULE,
};

static const struct of_device_id lpc18xx_pwm_of_match[] = {
	{ .compatible = "nxp,lpc1850-sct-pwm" },
	{}
};
MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);

static int lpc18xx_pwm_probe(struct platform_device *pdev)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm;
	int ret;
	u64 val;

	lpc18xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*lpc18xx_pwm),
				   GFP_KERNEL);
	if (!lpc18xx_pwm)
		return -ENOMEM;

	lpc18xx_pwm->dev = &pdev->dev;

	lpc18xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(lpc18xx_pwm->base))
		return PTR_ERR(lpc18xx_pwm->base);

	lpc18xx_pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
	if (IS_ERR(lpc18xx_pwm->pwm_clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(lpc18xx_pwm->pwm_clk),
				     "failed to get pwm clock\n");

	ret = clk_prepare_enable(lpc18xx_pwm->pwm_clk);
	if (ret < 0)
		return dev_err_probe(&pdev->dev, ret,
				     "could not prepare or enable pwm clock\n");

	lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
	if (!lpc18xx_pwm->clk_rate) {
		ret = dev_err_probe(&pdev->dev,
				    -EINVAL, "pwm clock has no frequency\n");
		goto disable_pwmclk;
	}

	/*
	 * If clkrate is too fast, the calculations in .apply() might overflow.
	 */
	if (lpc18xx_pwm->clk_rate > NSEC_PER_SEC) {
		ret = dev_err_probe(&pdev->dev, -EINVAL, "pwm clock to fast\n");
		goto disable_pwmclk;
	}

	mutex_init(&lpc18xx_pwm->res_lock);
	mutex_init(&lpc18xx_pwm->period_lock);

	lpc18xx_pwm->max_period_ns =
		mul_u64_u64_div_u64(NSEC_PER_SEC, LPC18XX_PWM_TIMER_MAX, lpc18xx_pwm->clk_rate);

	lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,
						  lpc18xx_pwm->clk_rate);

	lpc18xx_pwm->chip.dev = &pdev->dev;
	lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
	lpc18xx_pwm->chip.npwm = LPC18XX_NUM_PWMS;

	/* SCT counter must be in unify (32 bit) mode */
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
			   LPC18XX_PWM_CONFIG_UNIFY);

	/*
	 * Everytime the timer counter reaches the period value, the related
	 * event will be triggered and the counter reset to 0.
	 */
	set_bit(LPC18XX_PWM_EVENT_PERIOD, &lpc18xx_pwm->event_map);
	lpc18xx_pwm->period_event = LPC18XX_PWM_EVENT_PERIOD;

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_EVSTATEMSK(lpc18xx_pwm->period_event),
			   LPC18XX_PWM_EVSTATEMSK_ALL);

	val = LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_pwm->period_event) |
	      LPC18XX_PWM_EVCTRL_COMB_MATCH;
	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_EVCTRL(lpc18xx_pwm->period_event), val);

	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
			   BIT(lpc18xx_pwm->period_event));

	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	val &= ~LPC18XX_PWM_BIDIR;
	val &= ~LPC18XX_PWM_CTRL_HALT;
	val &= ~LPC18XX_PWM_PRE_MASK;
	val |= LPC18XX_PWM_PRE(0);
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);

	ret = pwmchip_add(&lpc18xx_pwm->chip);
	if (ret < 0) {
		dev_err_probe(&pdev->dev, ret, "pwmchip_add failed\n");
		goto disable_pwmclk;
	}

	platform_set_drvdata(pdev, lpc18xx_pwm);

	return 0;

disable_pwmclk:
	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
	return ret;
}

static int lpc18xx_pwm_remove(struct platform_device *pdev)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = platform_get_drvdata(pdev);
	u32 val;

	pwmchip_remove(&lpc18xx_pwm->chip);

	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL,
			   val | LPC18XX_PWM_CTRL_HALT);

	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);

	return 0;
}

static struct platform_driver lpc18xx_pwm_driver = {
	.driver = {
		.name = "lpc18xx-sct-pwm",
		.of_match_table = lpc18xx_pwm_of_match,
	},
	.probe = lpc18xx_pwm_probe,
	.remove = lpc18xx_pwm_remove,
};
module_platform_driver(lpc18xx_pwm_driver);

MODULE_AUTHOR("Ariel D'Alessandro <[email protected]>");
MODULE_DESCRIPTION("NXP LPC18xx PWM driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
84a14ae8	1	// SPDX-License-Identifier: GPL-2.0-only
841e6f90 AA	2	/*
	3	* NXP LPC18xx State Configurable Timer - Pulse Width Modulator driver
	4	*
	5	* Copyright (c) 2015 Ariel D'Alessandro <[email protected]>
	6	*
841e6f90 AA	7	* Notes
	8	* =====
	9	* NXP LPC18xx provides a State Configurable Timer (SCT) which can be configured
	10	* as a Pulse Width Modulator.
	11	*
	12	* SCT supports 16 outputs, 16 events and 16 registers. Each event will be
	13	* triggered when its related register matches the SCT counter value, and it
	14	* will set or clear a selected output.
	15	*
	16	* One of the events is preselected to generate the period, thus the maximum
	17	* number of simultaneous channels is limited to 15. Notice that period is
	18	* global to all the channels, thus PWM driver will refuse setting different
	19	* values to it, unless there's only one channel requested.
	20	*/
	21
	22	#include <linux/clk.h>
	23	#include <linux/err.h>
	24	#include <linux/io.h>
	25	#include <linux/module.h>
	26	#include <linux/platform_device.h>
	27	#include <linux/pwm.h>
	28
	29	/* LPC18xx SCT registers */
	30	#define LPC18XX_PWM_CONFIG 0x000
	31	#define LPC18XX_PWM_CONFIG_UNIFY BIT(0)
	32	#define LPC18XX_PWM_CONFIG_NORELOAD BIT(7)
	33
	34	#define LPC18XX_PWM_CTRL 0x004
	35	#define LPC18XX_PWM_CTRL_HALT BIT(2)
	36	#define LPC18XX_PWM_BIDIR BIT(4)
	37	#define LPC18XX_PWM_PRE_SHIFT 5
	38	#define LPC18XX_PWM_PRE_MASK (0xff << LPC18XX_PWM_PRE_SHIFT)
	39	#define LPC18XX_PWM_PRE(x) (x << LPC18XX_PWM_PRE_SHIFT)
	40
	41	#define LPC18XX_PWM_LIMIT 0x008
	42
	43	#define LPC18XX_PWM_RES_BASE 0x058
	44	#define LPC18XX_PWM_RES_SHIFT(_ch) (_ch * 2)
	45	#define LPC18XX_PWM_RES(_ch, _action) (_action << LPC18XX_PWM_RES_SHIFT(_ch))
	46	#define LPC18XX_PWM_RES_MASK(_ch) (0x3 << LPC18XX_PWM_RES_SHIFT(_ch))
	47
	48	#define LPC18XX_PWM_MATCH_BASE 0x100
	49	#define LPC18XX_PWM_MATCH(_ch) (LPC18XX_PWM_MATCH_BASE + _ch * 4)
	50
	51	#define LPC18XX_PWM_MATCHREL_BASE 0x200
	52	#define LPC18XX_PWM_MATCHREL(_ch) (LPC18XX_PWM_MATCHREL_BASE + _ch * 4)
	53
	54	#define LPC18XX_PWM_EVSTATEMSK_BASE 0x300
	55	#define LPC18XX_PWM_EVSTATEMSK(_ch) (LPC18XX_PWM_EVSTATEMSK_BASE + _ch * 8)
	56	#define LPC18XX_PWM_EVSTATEMSK_ALL 0xffffffff
	57
	58	#define LPC18XX_PWM_EVCTRL_BASE 0x304
	59	#define LPC18XX_PWM_EVCTRL(_ev) (LPC18XX_PWM_EVCTRL_BASE + _ev * 8)
	60
	61	#define LPC18XX_PWM_EVCTRL_MATCH(_ch) _ch
	62
	63	#define LPC18XX_PWM_EVCTRL_COMB_SHIFT 12
	64	#define LPC18XX_PWM_EVCTRL_COMB_MATCH (0x1 << LPC18XX_PWM_EVCTRL_COMB_SHIFT)
	65
	66	#define LPC18XX_PWM_OUTPUTSET_BASE 0x500
	67	#define LPC18XX_PWM_OUTPUTSET(_ch) (LPC18XX_PWM_OUTPUTSET_BASE + _ch * 8)
	68
	69	#define LPC18XX_PWM_OUTPUTCL_BASE 0x504
	70	#define LPC18XX_PWM_OUTPUTCL(_ch) (LPC18XX_PWM_OUTPUTCL_BASE + _ch * 8)
71
72	/* LPC18xx SCT unified counter */
73	#define LPC18XX_PWM_TIMER_MAX 0xffffffff
74
75	/* LPC18xx SCT events */
76	#define LPC18XX_PWM_EVENT_PERIOD 0
77	#define LPC18XX_PWM_EVENT_MAX 16
78
20d9de9c UKK	79	#define LPC18XX_NUM_PWMS 16
20d9de9c UKK	80
841e6f90 AA	81	/* SCT conflict resolution */
	82	enum lpc18xx_pwm_res_action {
	83	LPC18XX_PWM_RES_NONE,
	84	LPC18XX_PWM_RES_SET,
	85	LPC18XX_PWM_RES_CLEAR,
	86	LPC18XX_PWM_RES_TOGGLE,
	87	};
	88
	89	struct lpc18xx_pwm_data {
	90	unsigned int duty_event;
	91	};
	92
	93	struct lpc18xx_pwm_chip {
	94	struct device *dev;
	95	struct pwm_chip chip;
	96	void __iomem *base;
	97	struct clk *pwm_clk;
	98	unsigned long clk_rate;
	99	unsigned int period_ns;
	100	unsigned int min_period_ns;
8933d30c	101	u64 max_period_ns;
841e6f90 AA	102	unsigned int period_event;
	103	unsigned long event_map;
	104	struct mutex res_lock;
	105	struct mutex period_lock;
20d9de9c	106	struct lpc18xx_pwm_data channeldata[LPC18XX_NUM_PWMS];
841e6f90 AA	107	};
	108
	109	static inline struct lpc18xx_pwm_chip *
	110	to_lpc18xx_pwm_chip(struct pwm_chip *chip)
	111	{
	112	return container_of(chip, struct lpc18xx_pwm_chip, chip);
	113	}
	114
	115	static inline void lpc18xx_pwm_writel(struct lpc18xx_pwm_chip *lpc18xx_pwm,
	116	u32 reg, u32 val)
	117	{
	118	writel(val, lpc18xx_pwm->base + reg);
	119	}
	120
	121	static inline u32 lpc18xx_pwm_readl(struct lpc18xx_pwm_chip *lpc18xx_pwm,
	122	u32 reg)
	123	{
	124	return readl(lpc18xx_pwm->base + reg);
	125	}
	126
	127	static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
	128	struct pwm_device *pwm,
	129	enum lpc18xx_pwm_res_action action)
	130	{
	131	u32 val;
	132
	133	mutex_lock(&lpc18xx_pwm->res_lock);
	134
	135	/*
	136	* Simultaneous set and clear may happen on an output, that is the case
	137	* when duty_ns == period_ns. LPC18xx SCT allows to set a conflict
	138	* resolution action to be taken in such a case.
	139	*/
	140	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_RES_BASE);
	141	val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);
	142	val \|= LPC18XX_PWM_RES(pwm->hwpwm, action);
	143	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_RES_BASE, val);
	144
	145	mutex_unlock(&lpc18xx_pwm->res_lock);
	146	}
	147
8933d30c	148	static void lpc18xx_pwm_config_period(struct pwm_chip *chip, u64 period_ns)
841e6f90 AA	149	{
841e6f90 AA	150	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
8933d30c	151	u32 val;
841e6f90	152
8933d30c UKK	153	/*
	154	* With clk_rate < NSEC_PER_SEC this cannot overflow.
	155	* With period_ns < max_period_ns this also fits into an u32.
	156	* As period_ns >= min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC, lpc18xx_pwm->clk_rate);
	157	* we have val >= 1.
	158	*/
	159	val = mul_u64_u64_div_u64(period_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);
841e6f90 AA	160
	161	lpc18xx_pwm_writel(lpc18xx_pwm,
	162	LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),
8933d30c	163	val - 1);
841e6f90 AA	164
	165	lpc18xx_pwm_writel(lpc18xx_pwm,
	166	LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),
8933d30c	167	val - 1);
841e6f90 AA	168	}
	169
	170	static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
8933d30c	171	struct pwm_device *pwm, u64 duty_ns)
841e6f90 AA	172	{
841e6f90 AA	173	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
9136a39e	174	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
8933d30c	175	u32 val;
841e6f90	176
8933d30c UKK	177	/*
	178	* With clk_rate < NSEC_PER_SEC this cannot overflow.
	179	* With duty_ns <= period_ns < max_period_ns this also fits into an u32.
	180	*/
	181	val = mul_u64_u64_div_u64(duty_ns, lpc18xx_pwm->clk_rate, NSEC_PER_SEC);
841e6f90 AA	182
	183	lpc18xx_pwm_writel(lpc18xx_pwm,
	184	LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),
8933d30c	185	val);
841e6f90 AA	186
	187	lpc18xx_pwm_writel(lpc18xx_pwm,
	188	LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),
8933d30c	189	val);
841e6f90 AA	190	}
	191
	192	static int lpc18xx_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	193	int duty_ns, int period_ns)
	194	{
	195	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	196	int requested_events, i;
	197
	198	if (period_ns < lpc18xx_pwm->min_period_ns \|\|
	199	period_ns > lpc18xx_pwm->max_period_ns) {
	200	dev_err(chip->dev, "period %d not in range\n", period_ns);
	201	return -ERANGE;
	202	}
	203
	204	mutex_lock(&lpc18xx_pwm->period_lock);
	205
	206	requested_events = bitmap_weight(&lpc18xx_pwm->event_map,
	207	LPC18XX_PWM_EVENT_MAX);
	208
	209	/*
	210	* The PWM supports only a single period for all PWM channels.
	211	* Once the period is set, it can only be changed if no more than one
	212	* channel is requested at that moment.
	213	*/
	214	if (requested_events > 2 && lpc18xx_pwm->period_ns != period_ns &&
	215	lpc18xx_pwm->period_ns) {
	216	dev_err(chip->dev, "conflicting period requested for PWM %u\n",
	217	pwm->hwpwm);
	218	mutex_unlock(&lpc18xx_pwm->period_lock);
	219	return -EBUSY;
	220	}
	221
	222	if ((requested_events <= 2 && lpc18xx_pwm->period_ns != period_ns) \|\|
	223	!lpc18xx_pwm->period_ns) {
	224	lpc18xx_pwm->period_ns = period_ns;
	225	for (i = 0; i < chip->npwm; i++)
	226	pwm_set_period(&chip->pwms[i], period_ns);
	227	lpc18xx_pwm_config_period(chip, period_ns);
	228	}
	229
	230	mutex_unlock(&lpc18xx_pwm->period_lock);
	231
	232	lpc18xx_pwm_config_duty(chip, pwm, duty_ns);
	233
	234	return 0;
	235	}
	236
c449a8ca	237	static int lpc18xx_pwm_enable(struct pwm_chip chip, struct pwm_device pwm, enum pwm_polarity polarity)
841e6f90 AA	238	{
841e6f90 AA	239	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
9136a39e	240	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
841e6f90 AA	241	enum lpc18xx_pwm_res_action res_action;
	242	unsigned int set_event, clear_event;
	243
	244	lpc18xx_pwm_writel(lpc18xx_pwm,
	245	LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event),
	246	LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_data->duty_event) \|
	247	LPC18XX_PWM_EVCTRL_COMB_MATCH);
	248
	249	lpc18xx_pwm_writel(lpc18xx_pwm,
	250	LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
	251	LPC18XX_PWM_EVSTATEMSK_ALL);
	252
c449a8ca	253	if (polarity == PWM_POLARITY_NORMAL) {
841e6f90 AA	254	set_event = lpc18xx_pwm->period_event;
	255	clear_event = lpc18xx_data->duty_event;
	256	res_action = LPC18XX_PWM_RES_SET;
	257	} else {
	258	set_event = lpc18xx_data->duty_event;
	259	clear_event = lpc18xx_pwm->period_event;
	260	res_action = LPC18XX_PWM_RES_CLEAR;
	261	}
	262
	263	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm),
	264	BIT(set_event));
	265	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm),
	266	BIT(clear_event));
	267	lpc18xx_pwm_set_conflict_res(lpc18xx_pwm, pwm, res_action);
	268
	269	return 0;
	270	}
	271
	272	static void lpc18xx_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	273	{
	274	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
9136a39e	275	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
841e6f90 AA	276
	277	lpc18xx_pwm_writel(lpc18xx_pwm,
	278	LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);
	279	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm), 0);
	280	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm), 0);
	281	}
	282
	283	static int lpc18xx_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	284	{
	285	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
9136a39e	286	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
841e6f90 AA	287	unsigned long event;
	288
	289	event = find_first_zero_bit(&lpc18xx_pwm->event_map,
	290	LPC18XX_PWM_EVENT_MAX);
	291
	292	if (event >= LPC18XX_PWM_EVENT_MAX) {
	293	dev_err(lpc18xx_pwm->dev,
	294	"maximum number of simultaneous channels reached\n");
	295	return -EBUSY;
9a9dd7e4	296	}
841e6f90 AA	297
	298	set_bit(event, &lpc18xx_pwm->event_map);
	299	lpc18xx_data->duty_event = event;
841e6f90 AA	300
	301	return 0;
	302	}
	303
	304	static void lpc18xx_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	305	{
	306	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
9136a39e	307	struct lpc18xx_pwm_data *lpc18xx_data = &lpc18xx_pwm->channeldata[pwm->hwpwm];
841e6f90	308
841e6f90 AA	309	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
	310	}
	311
c449a8ca UKK	312	static int lpc18xx_pwm_apply(struct pwm_chip chip, struct pwm_device pwm,
	313	const struct pwm_state *state)
	314	{
	315	int err;
	316	bool enabled = pwm->state.enabled;
	317
	318	if (state->polarity != pwm->state.polarity && pwm->state.enabled) {
	319	lpc18xx_pwm_disable(chip, pwm);
	320	enabled = false;
	321	}
	322
	323	if (!state->enabled) {
	324	if (enabled)
	325	lpc18xx_pwm_disable(chip, pwm);
	326
	327	return 0;
	328	}
	329
	330	err = lpc18xx_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
	331	if (err)
	332	return err;
	333
	334	if (!enabled)
	335	err = lpc18xx_pwm_enable(chip, pwm, state->polarity);
	336
	337	return err;
	338	}
841e6f90	339	static const struct pwm_ops lpc18xx_pwm_ops = {
c449a8ca	340	.apply = lpc18xx_pwm_apply,
841e6f90 AA	341	.request = lpc18xx_pwm_request,
	342	.free = lpc18xx_pwm_free,
	343	.owner = THIS_MODULE,
	344	};
	345
	346	static const struct of_device_id lpc18xx_pwm_of_match[] = {
	347	{ .compatible = "nxp,lpc1850-sct-pwm" },
	348	{}
	349	};
	350	MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);
	351
	352	static int lpc18xx_pwm_probe(struct platform_device *pdev)
	353	{
	354	struct lpc18xx_pwm_chip *lpc18xx_pwm;
9136a39e	355	int ret;
841e6f90 AA	356	u64 val;
	357
	358	lpc18xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*lpc18xx_pwm),
	359	GFP_KERNEL);
	360	if (!lpc18xx_pwm)
	361	return -ENOMEM;
	362
	363	lpc18xx_pwm->dev = &pdev->dev;
	364
74ec20a4	365	lpc18xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
841e6f90 AA	366	if (IS_ERR(lpc18xx_pwm->base))
	367	return PTR_ERR(lpc18xx_pwm->base);
	368
	369	lpc18xx_pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
2ba1aede UKK	370	if (IS_ERR(lpc18xx_pwm->pwm_clk))
	371	return dev_err_probe(&pdev->dev, PTR_ERR(lpc18xx_pwm->pwm_clk),
	372	"failed to get pwm clock\n");
841e6f90 AA	373
841e6f90 AA	374	ret = clk_prepare_enable(lpc18xx_pwm->pwm_clk);
2ba1aede UKK	375	if (ret < 0)
	376	return dev_err_probe(&pdev->dev, ret,
	377	"could not prepare or enable pwm clock\n");
841e6f90 AA	378
841e6f90 AA	379	lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
0e47b598	380	if (!lpc18xx_pwm->clk_rate) {
2ba1aede UKK	381	ret = dev_err_probe(&pdev->dev,
2ba1aede UKK	382	-EINVAL, "pwm clock has no frequency\n");
0e47b598 WS	383	goto disable_pwmclk;
0e47b598 WS	384	}
841e6f90	385
8933d30c UKK	386	/*
	387	* If clkrate is too fast, the calculations in .apply() might overflow.
	388	*/
	389	if (lpc18xx_pwm->clk_rate > NSEC_PER_SEC) {
	390	ret = dev_err_probe(&pdev->dev, -EINVAL, "pwm clock to fast\n");
	391	goto disable_pwmclk;
	392	}
	393
841e6f90 AA	394	mutex_init(&lpc18xx_pwm->res_lock);
	395	mutex_init(&lpc18xx_pwm->period_lock);
	396
8933d30c UKK	397	lpc18xx_pwm->max_period_ns =
8933d30c UKK	398	mul_u64_u64_div_u64(NSEC_PER_SEC, LPC18XX_PWM_TIMER_MAX, lpc18xx_pwm->clk_rate);
841e6f90 AA	399
	400	lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,
	401	lpc18xx_pwm->clk_rate);
	402
	403	lpc18xx_pwm->chip.dev = &pdev->dev;
	404	lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
20d9de9c	405	lpc18xx_pwm->chip.npwm = LPC18XX_NUM_PWMS;
841e6f90 AA	406
	407	/* SCT counter must be in unify (32 bit) mode */
	408	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
	409	LPC18XX_PWM_CONFIG_UNIFY);
	410
	411	/*
	412	* Everytime the timer counter reaches the period value, the related
	413	* event will be triggered and the counter reset to 0.
	414	*/
	415	set_bit(LPC18XX_PWM_EVENT_PERIOD, &lpc18xx_pwm->event_map);
	416	lpc18xx_pwm->period_event = LPC18XX_PWM_EVENT_PERIOD;
	417
	418	lpc18xx_pwm_writel(lpc18xx_pwm,
	419	LPC18XX_PWM_EVSTATEMSK(lpc18xx_pwm->period_event),
	420	LPC18XX_PWM_EVSTATEMSK_ALL);
	421
	422	val = LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_pwm->period_event) \|
	423	LPC18XX_PWM_EVCTRL_COMB_MATCH;
	424	lpc18xx_pwm_writel(lpc18xx_pwm,
	425	LPC18XX_PWM_EVCTRL(lpc18xx_pwm->period_event), val);
	426
	427	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
	428	BIT(lpc18xx_pwm->period_event));
	429
841e6f90 AA	430	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	431	val &= ~LPC18XX_PWM_BIDIR;
	432	val &= ~LPC18XX_PWM_CTRL_HALT;
	433	val &= ~LPC18XX_PWM_PRE_MASK;
	434	val \|= LPC18XX_PWM_PRE(0);
	435	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);
	436
0401f24c UKK	437	ret = pwmchip_add(&lpc18xx_pwm->chip);
0401f24c UKK	438	if (ret < 0) {
2ba1aede	439	dev_err_probe(&pdev->dev, ret, "pwmchip_add failed\n");
0401f24c UKK	440	goto disable_pwmclk;
	441	}
	442
	443	platform_set_drvdata(pdev, lpc18xx_pwm);
	444
841e6f90 AA	445	return 0;
841e6f90 AA	446
841e6f90 AA	447	disable_pwmclk:
	448	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
	449	return ret;
	450	}
	451
	452	static int lpc18xx_pwm_remove(struct platform_device *pdev)
	453	{
	454	struct lpc18xx_pwm_chip *lpc18xx_pwm = platform_get_drvdata(pdev);
	455	u32 val;
	456
d58a484e UKK	457	pwmchip_remove(&lpc18xx_pwm->chip);
d58a484e UKK	458
841e6f90 AA	459	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	460	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL,
	461	val \| LPC18XX_PWM_CTRL_HALT);
	462
	463	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
	464
d58a484e	465	return 0;
841e6f90 AA	466	}
	467
	468	static struct platform_driver lpc18xx_pwm_driver = {
	469	.driver = {
	470	.name = "lpc18xx-sct-pwm",
	471	.of_match_table = lpc18xx_pwm_of_match,
	472	},
	473	.probe = lpc18xx_pwm_probe,
	474	.remove = lpc18xx_pwm_remove,
	475	};
	476	module_platform_driver(lpc18xx_pwm_driver);
	477
	478	MODULE_AUTHOR("Ariel D'Alessandro <[email protected]>");
	479	MODULE_DESCRIPTION("NXP LPC18xx PWM driver");
	480	MODULE_LICENSE("GPL v2");