[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

/* 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;
	unsigned int max_period_ns;
	unsigned int period_event;
	unsigned long event_map;
	struct mutex res_lock;
	struct mutex period_lock;
};

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, int period_ns)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	u64 val;

	val = (u64)period_ns * lpc18xx_pwm->clk_rate;
	do_div(val, NSEC_PER_SEC);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),
			   (u32)val - 1);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),
			   (u32)val - 1);
}

static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
				    struct pwm_device *pwm, int duty_ns)
{
	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
	u64 val;

	val = (u64)duty_ns * lpc18xx_pwm->clk_rate;
	do_div(val, NSEC_PER_SEC);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),
			   (u32)val);

	lpc18xx_pwm_writel(lpc18xx_pwm,
			   LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),
			   (u32)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_set_polarity(struct pwm_chip *chip,
				    struct pwm_device *pwm,
				    enum pwm_polarity polarity)
{
	return 0;
}

static int lpc18xx_pwm_enable(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 = pwm_get_chip_data(pwm);
	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 (pwm_get_polarity(pwm) == 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 = pwm_get_chip_data(pwm);

	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 = pwm_get_chip_data(pwm);
	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 = pwm_get_chip_data(pwm);

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

static const struct pwm_ops lpc18xx_pwm_ops = {
	.config = lpc18xx_pwm_config,
	.set_polarity = lpc18xx_pwm_set_polarity,
	.enable = lpc18xx_pwm_enable,
	.disable = lpc18xx_pwm_disable,
	.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;
	struct pwm_device *pwm;
	struct resource *res;
	int ret, i;
	u64 val;

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

	lpc18xx_pwm->dev = &pdev->dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	lpc18xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
	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)) {
		dev_err(&pdev->dev, "failed to get pwm clock\n");
		return PTR_ERR(lpc18xx_pwm->pwm_clk);
	}

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

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

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

	val = (u64)NSEC_PER_SEC * LPC18XX_PWM_TIMER_MAX;
	do_div(val, lpc18xx_pwm->clk_rate);
	lpc18xx_pwm->max_period_ns = val;

	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.base = -1;
	lpc18xx_pwm->chip.npwm = 16;
	lpc18xx_pwm->chip.of_xlate = of_pwm_xlate_with_flags;
	lpc18xx_pwm->chip.of_pwm_n_cells = 3;

	/* 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));

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

	for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
		struct lpc18xx_pwm_data *data;

		pwm = &lpc18xx_pwm->chip.pwms[i];

		data = devm_kzalloc(lpc18xx_pwm->dev, sizeof(*data),
				    GFP_KERNEL);
		if (!data) {
			ret = -ENOMEM;
			goto remove_pwmchip;
		}

		pwm_set_chip_data(pwm, data);
	}

	platform_set_drvdata(pdev, lpc18xx_pwm);

	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);

	return 0;

remove_pwmchip:
	pwmchip_remove(&lpc18xx_pwm->chip);
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;

	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 pwmchip_remove(&lpc18xx_pwm->chip);
}

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
79	/* SCT conflict resolution */
80	enum lpc18xx_pwm_res_action {
81	LPC18XX_PWM_RES_NONE,
82	LPC18XX_PWM_RES_SET,
83	LPC18XX_PWM_RES_CLEAR,
84	LPC18XX_PWM_RES_TOGGLE,
85	};
86
87	struct lpc18xx_pwm_data {
88	unsigned int duty_event;
89	};
90
91	struct lpc18xx_pwm_chip {
92	struct device *dev;
93	struct pwm_chip chip;
94	void __iomem *base;
95	struct clk *pwm_clk;
96	unsigned long clk_rate;
97	unsigned int period_ns;
98	unsigned int min_period_ns;
99	unsigned int max_period_ns;
100	unsigned int period_event;
101	unsigned long event_map;
102	struct mutex res_lock;
103	struct mutex period_lock;
104	};
105
106	static inline struct lpc18xx_pwm_chip *
107	to_lpc18xx_pwm_chip(struct pwm_chip *chip)
108	{
109	return container_of(chip, struct lpc18xx_pwm_chip, chip);
110	}
111
112	static inline void lpc18xx_pwm_writel(struct lpc18xx_pwm_chip *lpc18xx_pwm,
113	u32 reg, u32 val)
114	{
115	writel(val, lpc18xx_pwm->base + reg);
116	}
117
118	static inline u32 lpc18xx_pwm_readl(struct lpc18xx_pwm_chip *lpc18xx_pwm,
119	u32 reg)
120	{
121	return readl(lpc18xx_pwm->base + reg);
122	}
123
124	static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
125	struct pwm_device *pwm,
126	enum lpc18xx_pwm_res_action action)
127	{
128	u32 val;
129
130	mutex_lock(&lpc18xx_pwm->res_lock);
131
132	/*
133	* Simultaneous set and clear may happen on an output, that is the case
134	* when duty_ns == period_ns. LPC18xx SCT allows to set a conflict
135	* resolution action to be taken in such a case.
136	*/
137	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_RES_BASE);
138	val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);
139	val \|= LPC18XX_PWM_RES(pwm->hwpwm, action);
140	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_RES_BASE, val);
141
142	mutex_unlock(&lpc18xx_pwm->res_lock);
143	}
144
145	static void lpc18xx_pwm_config_period(struct pwm_chip *chip, int period_ns)
146	{
147	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
148	u64 val;
149
150	val = (u64)period_ns * lpc18xx_pwm->clk_rate;
151	do_div(val, NSEC_PER_SEC);
152
153	lpc18xx_pwm_writel(lpc18xx_pwm,
154	LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),
155	(u32)val - 1);
156
157	lpc18xx_pwm_writel(lpc18xx_pwm,
158	LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),
159	(u32)val - 1);
160	}
161
162	static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
163	struct pwm_device *pwm, int duty_ns)
164	{
165	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
166	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
167	u64 val;
168
169	val = (u64)duty_ns * lpc18xx_pwm->clk_rate;
170	do_div(val, NSEC_PER_SEC);
171
172	lpc18xx_pwm_writel(lpc18xx_pwm,
173	LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),
174	(u32)val);
175
176	lpc18xx_pwm_writel(lpc18xx_pwm,
177	LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),
178	(u32)val);
179	}
180
181	static int lpc18xx_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
182	int duty_ns, int period_ns)
183	{
184	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
185	int requested_events, i;
186
187	if (period_ns < lpc18xx_pwm->min_period_ns \|\|
188	period_ns > lpc18xx_pwm->max_period_ns) {
189	dev_err(chip->dev, "period %d not in range\n", period_ns);
190	return -ERANGE;
191	}
192
193	mutex_lock(&lpc18xx_pwm->period_lock);
194
195	requested_events = bitmap_weight(&lpc18xx_pwm->event_map,
196	LPC18XX_PWM_EVENT_MAX);
197
198	/*
199	* The PWM supports only a single period for all PWM channels.
200	* Once the period is set, it can only be changed if no more than one
201	* channel is requested at that moment.
202	*/
203	if (requested_events > 2 && lpc18xx_pwm->period_ns != period_ns &&
204	lpc18xx_pwm->period_ns) {
205	dev_err(chip->dev, "conflicting period requested for PWM %u\n",
206	pwm->hwpwm);
207	mutex_unlock(&lpc18xx_pwm->period_lock);
208	return -EBUSY;
209	}
210
211	if ((requested_events <= 2 && lpc18xx_pwm->period_ns != period_ns) \|\|
212	!lpc18xx_pwm->period_ns) {
213	lpc18xx_pwm->period_ns = period_ns;
214	for (i = 0; i < chip->npwm; i++)
215	pwm_set_period(&chip->pwms[i], period_ns);
216	lpc18xx_pwm_config_period(chip, period_ns);
217	}
218
219	mutex_unlock(&lpc18xx_pwm->period_lock);
220
221	lpc18xx_pwm_config_duty(chip, pwm, duty_ns);
222
223	return 0;
224	}
225
226	static int lpc18xx_pwm_set_polarity(struct pwm_chip *chip,
227	struct pwm_device *pwm,
228	enum pwm_polarity polarity)
229	{
230	return 0;
231	}
232
233	static int lpc18xx_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
234	{
235	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
236	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
237	enum lpc18xx_pwm_res_action res_action;
238	unsigned int set_event, clear_event;
239
240	lpc18xx_pwm_writel(lpc18xx_pwm,
241	LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event),
242	LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_data->duty_event) \|
243	LPC18XX_PWM_EVCTRL_COMB_MATCH);
244
245	lpc18xx_pwm_writel(lpc18xx_pwm,
246	LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
247	LPC18XX_PWM_EVSTATEMSK_ALL);
248
4b58896f	249	if (pwm_get_polarity(pwm) == PWM_POLARITY_NORMAL) {
841e6f90 AA	250	set_event = lpc18xx_pwm->period_event;
	251	clear_event = lpc18xx_data->duty_event;
	252	res_action = LPC18XX_PWM_RES_SET;
	253	} else {
	254	set_event = lpc18xx_data->duty_event;
	255	clear_event = lpc18xx_pwm->period_event;
	256	res_action = LPC18XX_PWM_RES_CLEAR;
	257	}
	258
	259	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm),
	260	BIT(set_event));
	261	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm),
	262	BIT(clear_event));
	263	lpc18xx_pwm_set_conflict_res(lpc18xx_pwm, pwm, res_action);
	264
	265	return 0;
	266	}
	267
	268	static void lpc18xx_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	269	{
	270	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	271	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
	272
	273	lpc18xx_pwm_writel(lpc18xx_pwm,
	274	LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);
	275	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm), 0);
	276	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm), 0);
	277	}
	278
	279	static int lpc18xx_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	280	{
	281	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	282	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
	283	unsigned long event;
	284
	285	event = find_first_zero_bit(&lpc18xx_pwm->event_map,
	286	LPC18XX_PWM_EVENT_MAX);
	287
	288	if (event >= LPC18XX_PWM_EVENT_MAX) {
	289	dev_err(lpc18xx_pwm->dev,
	290	"maximum number of simultaneous channels reached\n");
	291	return -EBUSY;
	292	};
	293
	294	set_bit(event, &lpc18xx_pwm->event_map);
	295	lpc18xx_data->duty_event = event;
841e6f90 AA	296
	297	return 0;
	298	}
	299
	300	static void lpc18xx_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	301	{
	302	struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
	303	struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
	304
841e6f90 AA	305	clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
	306	}
	307
	308	static const struct pwm_ops lpc18xx_pwm_ops = {
	309	.config = lpc18xx_pwm_config,
	310	.set_polarity = lpc18xx_pwm_set_polarity,
	311	.enable = lpc18xx_pwm_enable,
	312	.disable = lpc18xx_pwm_disable,
	313	.request = lpc18xx_pwm_request,
	314	.free = lpc18xx_pwm_free,
	315	.owner = THIS_MODULE,
	316	};
	317
	318	static const struct of_device_id lpc18xx_pwm_of_match[] = {
	319	{ .compatible = "nxp,lpc1850-sct-pwm" },
	320	{}
	321	};
	322	MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);
	323
	324	static int lpc18xx_pwm_probe(struct platform_device *pdev)
	325	{
	326	struct lpc18xx_pwm_chip *lpc18xx_pwm;
	327	struct pwm_device *pwm;
	328	struct resource *res;
	329	int ret, i;
	330	u64 val;
	331
	332	lpc18xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*lpc18xx_pwm),
	333	GFP_KERNEL);
	334	if (!lpc18xx_pwm)
	335	return -ENOMEM;
	336
	337	lpc18xx_pwm->dev = &pdev->dev;
	338
	339	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	340	lpc18xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
	341	if (IS_ERR(lpc18xx_pwm->base))
	342	return PTR_ERR(lpc18xx_pwm->base);
	343
	344	lpc18xx_pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
	345	if (IS_ERR(lpc18xx_pwm->pwm_clk)) {
	346	dev_err(&pdev->dev, "failed to get pwm clock\n");
	347	return PTR_ERR(lpc18xx_pwm->pwm_clk);
	348	}
	349
	350	ret = clk_prepare_enable(lpc18xx_pwm->pwm_clk);
	351	if (ret < 0) {
	352	dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");
	353	return ret;
	354	}
	355
	356	lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
0e47b598 WS	357	if (!lpc18xx_pwm->clk_rate) {
	358	dev_err(&pdev->dev, "pwm clock has no frequency\n");
	359	ret = -EINVAL;
	360	goto disable_pwmclk;
	361	}
841e6f90 AA	362
	363	mutex_init(&lpc18xx_pwm->res_lock);
	364	mutex_init(&lpc18xx_pwm->period_lock);
	365
	366	val = (u64)NSEC_PER_SEC * LPC18XX_PWM_TIMER_MAX;
	367	do_div(val, lpc18xx_pwm->clk_rate);
	368	lpc18xx_pwm->max_period_ns = val;
	369
	370	lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,
	371	lpc18xx_pwm->clk_rate);
	372
	373	lpc18xx_pwm->chip.dev = &pdev->dev;
	374	lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
	375	lpc18xx_pwm->chip.base = -1;
	376	lpc18xx_pwm->chip.npwm = 16;
	377	lpc18xx_pwm->chip.of_xlate = of_pwm_xlate_with_flags;
	378	lpc18xx_pwm->chip.of_pwm_n_cells = 3;
	379
	380	/* SCT counter must be in unify (32 bit) mode */
	381	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
	382	LPC18XX_PWM_CONFIG_UNIFY);
	383
	384	/*
	385	* Everytime the timer counter reaches the period value, the related
	386	* event will be triggered and the counter reset to 0.
	387	*/
	388	set_bit(LPC18XX_PWM_EVENT_PERIOD, &lpc18xx_pwm->event_map);
	389	lpc18xx_pwm->period_event = LPC18XX_PWM_EVENT_PERIOD;
	390
	391	lpc18xx_pwm_writel(lpc18xx_pwm,
	392	LPC18XX_PWM_EVSTATEMSK(lpc18xx_pwm->period_event),
	393	LPC18XX_PWM_EVSTATEMSK_ALL);
	394
	395	val = LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_pwm->period_event) \|
	396	LPC18XX_PWM_EVCTRL_COMB_MATCH;
	397	lpc18xx_pwm_writel(lpc18xx_pwm,
	398	LPC18XX_PWM_EVCTRL(lpc18xx_pwm->period_event), val);
	399
	400	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
	401	BIT(lpc18xx_pwm->period_event));
	402
	403	ret = pwmchip_add(&lpc18xx_pwm->chip);
	404	if (ret < 0) {
	405	dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
	406	goto disable_pwmclk;
	407	}
	408
	409	for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
fe0e2cf9	410	struct lpc18xx_pwm_data *data;
fe0e2cf9	411
841e6f90	412	pwm = &lpc18xx_pwm->chip.pwms[i];
fe0e2cf9	413
	414	data = devm_kzalloc(lpc18xx_pwm->dev, sizeof(*data),
	415	GFP_KERNEL);
	416	if (!data) {
841e6f90 AA	417	ret = -ENOMEM;
	418	goto remove_pwmchip;
	419	}
fe0e2cf9	420
fe0e2cf9	421	pwm_set_chip_data(pwm, data);
841e6f90 AA	422	}
	423
	424	platform_set_drvdata(pdev, lpc18xx_pwm);
	425
	426	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	427	val &= ~LPC18XX_PWM_BIDIR;
	428	val &= ~LPC18XX_PWM_CTRL_HALT;
	429	val &= ~LPC18XX_PWM_PRE_MASK;
	430	val \|= LPC18XX_PWM_PRE(0);
	431	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);
	432
	433	return 0;
	434
	435	remove_pwmchip:
	436	pwmchip_remove(&lpc18xx_pwm->chip);
	437	disable_pwmclk:
	438	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
	439	return ret;
	440	}
	441
	442	static int lpc18xx_pwm_remove(struct platform_device *pdev)
	443	{
	444	struct lpc18xx_pwm_chip *lpc18xx_pwm = platform_get_drvdata(pdev);
	445	u32 val;
	446
	447	val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
	448	lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL,
	449	val \| LPC18XX_PWM_CTRL_HALT);
	450
	451	clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
	452
	453	return pwmchip_remove(&lpc18xx_pwm->chip);
	454	}
	455
	456	static struct platform_driver lpc18xx_pwm_driver = {
	457	.driver = {
	458	.name = "lpc18xx-sct-pwm",
	459	.of_match_table = lpc18xx_pwm_of_match,
	460	},
	461	.probe = lpc18xx_pwm_probe,
	462	.remove = lpc18xx_pwm_remove,
	463	};
	464	module_platform_driver(lpc18xx_pwm_driver);
	465
	466	MODULE_AUTHOR("Ariel D'Alessandro <[email protected]>");
	467	MODULE_DESCRIPTION("NXP LPC18xx PWM driver");
	468	MODULE_LICENSE("GPL v2");