[linux-block.git] / drivers / pwm / pwm-bcm-iproc.c

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (C) 2016 Broadcom

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>

#define IPROC_PWM_CTRL_OFFSET			0x00
#define IPROC_PWM_CTRL_TYPE_SHIFT(ch)		(15 + (ch))
#define IPROC_PWM_CTRL_POLARITY_SHIFT(ch)	(8 + (ch))
#define IPROC_PWM_CTRL_EN_SHIFT(ch)		(ch)

#define IPROC_PWM_PERIOD_OFFSET(ch)		(0x04 + ((ch) << 3))
#define IPROC_PWM_PERIOD_MIN			0x02
#define IPROC_PWM_PERIOD_MAX			0xffff

#define IPROC_PWM_DUTY_CYCLE_OFFSET(ch)		(0x08 + ((ch) << 3))
#define IPROC_PWM_DUTY_CYCLE_MIN		0x00
#define IPROC_PWM_DUTY_CYCLE_MAX		0xffff

#define IPROC_PWM_PRESCALE_OFFSET		0x24
#define IPROC_PWM_PRESCALE_BITS			0x06
#define IPROC_PWM_PRESCALE_SHIFT(ch)		((3 - (ch)) * \
						 IPROC_PWM_PRESCALE_BITS)
#define IPROC_PWM_PRESCALE_MASK(ch)		(IPROC_PWM_PRESCALE_MAX << \
						 IPROC_PWM_PRESCALE_SHIFT(ch))
#define IPROC_PWM_PRESCALE_MIN			0x00
#define IPROC_PWM_PRESCALE_MAX			0x3f

struct iproc_pwmc {
	struct pwm_chip chip;
	void __iomem *base;
	struct clk *clk;
};

static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *chip)
{
	return container_of(chip, struct iproc_pwmc, chip);
}

static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel)
{
	u32 value;

	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel);
	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);

	/* must be a 400 ns delay between clearing and setting enable bit */
	ndelay(400);
}

static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel)
{
	u32 value;

	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel));
	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);

	/* must be a 400 ns delay between clearing and setting enable bit */
	ndelay(400);
}

static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
				 struct pwm_state *state)
{
	struct iproc_pwmc *ip = to_iproc_pwmc(chip);
	u64 tmp, multi, rate;
	u32 value, prescale;

	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);

	if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
		state->enabled = true;
	else
		state->enabled = false;

	if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
		state->polarity = PWM_POLARITY_NORMAL;
	else
		state->polarity = PWM_POLARITY_INVERSED;

	rate = clk_get_rate(ip->clk);
	if (rate == 0) {
		state->period = 0;
		state->duty_cycle = 0;
		return;
	}

	value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
	prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
	prescale &= IPROC_PWM_PRESCALE_MAX;

	multi = NSEC_PER_SEC * (prescale + 1);

	value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
	tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
	state->period = div64_u64(tmp, rate);

	value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
	tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
	state->duty_cycle = div64_u64(tmp, rate);
}

static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
			    const struct pwm_state *state)
{
	unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
	struct iproc_pwmc *ip = to_iproc_pwmc(chip);
	u32 value, period, duty;
	u64 rate;

	rate = clk_get_rate(ip->clk);

	/*
	 * Find period count, duty count and prescale to suit duty_cycle and
	 * period. This is done according to formulas described below:
	 *
	 * period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE
	 * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
	 *
	 * PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1))
	 * DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1))
	 */
	while (1) {
		u64 value, div;

		div = NSEC_PER_SEC * (prescale + 1);
		value = rate * state->period;
		period = div64_u64(value, div);
		value = rate * state->duty_cycle;
		duty = div64_u64(value, div);

		if (period < IPROC_PWM_PERIOD_MIN)
			return -EINVAL;

		if (period <= IPROC_PWM_PERIOD_MAX &&
		     duty <= IPROC_PWM_DUTY_CYCLE_MAX)
			break;

		/* Otherwise, increase prescale and recalculate counts */
		if (++prescale > IPROC_PWM_PRESCALE_MAX)
			return -EINVAL;
	}

	iproc_pwmc_disable(ip, pwm->hwpwm);

	/* Set prescale */
	value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
	value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
	value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
	writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);

	/* set period and duty cycle */
	writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
	writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));

	/* set polarity */
	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);

	if (state->polarity == PWM_POLARITY_NORMAL)
		value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
	else
		value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));

	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);

	if (state->enabled)
		iproc_pwmc_enable(ip, pwm->hwpwm);

	return 0;
}

static const struct pwm_ops iproc_pwm_ops = {
	.apply = iproc_pwmc_apply,
	.get_state = iproc_pwmc_get_state,
	.owner = THIS_MODULE,
};

static int iproc_pwmc_probe(struct platform_device *pdev)
{
	struct iproc_pwmc *ip;
	unsigned int i;
	u32 value;
	int ret;

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

	platform_set_drvdata(pdev, ip);

	ip->chip.dev = &pdev->dev;
	ip->chip.ops = &iproc_pwm_ops;
	ip->chip.npwm = 4;

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

	ip->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(ip->clk)) {
		dev_err(&pdev->dev, "failed to get clock: %ld\n",
			PTR_ERR(ip->clk));
		return PTR_ERR(ip->clk);
	}

	ret = clk_prepare_enable(ip->clk);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
		return ret;
	}

	/* Set full drive and normal polarity for all channels */
	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);

	for (i = 0; i < ip->chip.npwm; i++) {
		value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
		value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
	}

	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);

	ret = pwmchip_add(&ip->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
		clk_disable_unprepare(ip->clk);
	}

	return ret;
}

static int iproc_pwmc_remove(struct platform_device *pdev)
{
	struct iproc_pwmc *ip = platform_get_drvdata(pdev);

	pwmchip_remove(&ip->chip);

	clk_disable_unprepare(ip->clk);

	return 0;
}

static const struct of_device_id bcm_iproc_pwmc_dt[] = {
	{ .compatible = "brcm,iproc-pwm" },
	{ },
};
MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);

static struct platform_driver iproc_pwmc_driver = {
	.driver = {
		.name = "bcm-iproc-pwm",
		.of_match_table = bcm_iproc_pwmc_dt,
	},
	.probe = iproc_pwmc_probe,
	.remove = iproc_pwmc_remove,
};
module_platform_driver(iproc_pwmc_driver);

MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
MODULE_DESCRIPTION("Broadcom iProc PWM driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2aec85b2 TG	1	// SPDX-License-Identifier: GPL-2.0-only
2aec85b2 TG	2	// Copyright (C) 2016 Broadcom
daa5abc4 YRDR	3
	4	#include <linux/clk.h>
	5	#include <linux/delay.h>
	6	#include <linux/err.h>
	7	#include <linux/io.h>
	8	#include <linux/math64.h>
	9	#include <linux/module.h>
	10	#include <linux/of.h>
	11	#include <linux/platform_device.h>
	12	#include <linux/pwm.h>
	13
	14	#define IPROC_PWM_CTRL_OFFSET 0x00
	15	#define IPROC_PWM_CTRL_TYPE_SHIFT(ch) (15 + (ch))
	16	#define IPROC_PWM_CTRL_POLARITY_SHIFT(ch) (8 + (ch))
	17	#define IPROC_PWM_CTRL_EN_SHIFT(ch) (ch)
	18
	19	#define IPROC_PWM_PERIOD_OFFSET(ch) (0x04 + ((ch) << 3))
	20	#define IPROC_PWM_PERIOD_MIN 0x02
	21	#define IPROC_PWM_PERIOD_MAX 0xffff
	22
	23	#define IPROC_PWM_DUTY_CYCLE_OFFSET(ch) (0x08 + ((ch) << 3))
	24	#define IPROC_PWM_DUTY_CYCLE_MIN 0x00
	25	#define IPROC_PWM_DUTY_CYCLE_MAX 0xffff
	26
	27	#define IPROC_PWM_PRESCALE_OFFSET 0x24
	28	#define IPROC_PWM_PRESCALE_BITS 0x06
	29	#define IPROC_PWM_PRESCALE_SHIFT(ch) ((3 - (ch)) * \
	30	IPROC_PWM_PRESCALE_BITS)
	31	#define IPROC_PWM_PRESCALE_MASK(ch) (IPROC_PWM_PRESCALE_MAX << \
	32	IPROC_PWM_PRESCALE_SHIFT(ch))
	33	#define IPROC_PWM_PRESCALE_MIN 0x00
	34	#define IPROC_PWM_PRESCALE_MAX 0x3f
	35
	36	struct iproc_pwmc {
	37	struct pwm_chip chip;
	38	void __iomem *base;
	39	struct clk *clk;
	40	};
	41
	42	static inline struct iproc_pwmc to_iproc_pwmc(struct pwm_chip chip)
	43	{
	44	return container_of(chip, struct iproc_pwmc, chip);
	45	}
	46
	47	static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel)
	48	{
	49	u32 value;
	50
	51	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	52	value \|= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel);
	53	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
	54
	55	/* must be a 400 ns delay between clearing and setting enable bit */
	56	ndelay(400);
	57	}
	58
	59	static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel)
	60	{
	61	u32 value;
	62
	63	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	64	value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel));
	65	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
	66
67	/* must be a 400 ns delay between clearing and setting enable bit */
68	ndelay(400);
69	}
70
71	static void iproc_pwmc_get_state(struct pwm_chip chip, struct pwm_device pwm,
72	struct pwm_state *state)
73	{
74	struct iproc_pwmc *ip = to_iproc_pwmc(chip);
75	u64 tmp, multi, rate;
76	u32 value, prescale;
77
daa5abc4 YRDR	78	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	79
	80	if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
	81	state->enabled = true;
	82	else
	83	state->enabled = false;
	84
	85	if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
	86	state->polarity = PWM_POLARITY_NORMAL;
	87	else
	88	state->polarity = PWM_POLARITY_INVERSED;
	89
6ced5ff0 RK	90	rate = clk_get_rate(ip->clk);
	91	if (rate == 0) {
	92	state->period = 0;
	93	state->duty_cycle = 0;
	94	return;
	95	}
	96
daa5abc4 YRDR	97	value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
	98	prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
	99	prescale &= IPROC_PWM_PRESCALE_MAX;
	100
	101	multi = NSEC_PER_SEC * (prescale + 1);
	102
	103	value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
	104	tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
	105	state->period = div64_u64(tmp, rate);
	106
	107	value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
	108	tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
	109	state->duty_cycle = div64_u64(tmp, rate);
	110	}
	111
	112	static int iproc_pwmc_apply(struct pwm_chip chip, struct pwm_device pwm,
71523d18	113	const struct pwm_state *state)
daa5abc4 YRDR	114	{
	115	unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
	116	struct iproc_pwmc *ip = to_iproc_pwmc(chip);
	117	u32 value, period, duty;
	118	u64 rate;
	119
	120	rate = clk_get_rate(ip->clk);
	121
	122	/*
	123	* Find period count, duty count and prescale to suit duty_cycle and
	124	* period. This is done according to formulas described below:
	125	*
	126	* period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE
	127	* duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
	128	*
	129	* PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1))
	130	* DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1))
	131	*/
	132	while (1) {
	133	u64 value, div;
	134
	135	div = NSEC_PER_SEC * (prescale + 1);
	136	value = rate * state->period;
	137	period = div64_u64(value, div);
	138	value = rate * state->duty_cycle;
	139	duty = div64_u64(value, div);
	140
9443f2c8	141	if (period < IPROC_PWM_PERIOD_MIN)
daa5abc4 YRDR	142	return -EINVAL;
	143
	144	if (period <= IPROC_PWM_PERIOD_MAX &&
	145	duty <= IPROC_PWM_DUTY_CYCLE_MAX)
	146	break;
	147
	148	/* Otherwise, increase prescale and recalculate counts */
	149	if (++prescale > IPROC_PWM_PRESCALE_MAX)
	150	return -EINVAL;
	151	}
	152
	153	iproc_pwmc_disable(ip, pwm->hwpwm);
	154
	155	/* Set prescale */
	156	value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
	157	value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
	158	value \|= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
	159	writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);
	160
	161	/* set period and duty cycle */
	162	writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
	163	writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
	164
	165	/* set polarity */
	166	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	167
	168	if (state->polarity == PWM_POLARITY_NORMAL)
	169	value \|= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
	170	else
	171	value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));
	172
	173	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
	174
	175	if (state->enabled)
	176	iproc_pwmc_enable(ip, pwm->hwpwm);
	177
	178	return 0;
	179	}
	180
	181	static const struct pwm_ops iproc_pwm_ops = {
	182	.apply = iproc_pwmc_apply,
	183	.get_state = iproc_pwmc_get_state,
24906a41	184	.owner = THIS_MODULE,
daa5abc4 YRDR	185	};
	186
	187	static int iproc_pwmc_probe(struct platform_device *pdev)
	188	{
	189	struct iproc_pwmc *ip;
daa5abc4 YRDR	190	unsigned int i;
	191	u32 value;
	192	int ret;
	193
	194	ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL);
	195	if (!ip)
	196	return -ENOMEM;
	197
	198	platform_set_drvdata(pdev, ip);
	199
	200	ip->chip.dev = &pdev->dev;
	201	ip->chip.ops = &iproc_pwm_ops;
daa5abc4	202	ip->chip.npwm = 4;
daa5abc4	203
ed98401f	204	ip->base = devm_platform_ioremap_resource(pdev, 0);
daa5abc4 YRDR	205	if (IS_ERR(ip->base))
	206	return PTR_ERR(ip->base);
	207
	208	ip->clk = devm_clk_get(&pdev->dev, NULL);
	209	if (IS_ERR(ip->clk)) {
	210	dev_err(&pdev->dev, "failed to get clock: %ld\n",
	211	PTR_ERR(ip->clk));
	212	return PTR_ERR(ip->clk);
	213	}
	214
	215	ret = clk_prepare_enable(ip->clk);
	216	if (ret < 0) {
	217	dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
	218	return ret;
	219	}
	220
	221	/* Set full drive and normal polarity for all channels */
	222	value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
	223
	224	for (i = 0; i < ip->chip.npwm; i++) {
	225	value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
	226	value \|= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
	227	}
	228
	229	writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
	230
	231	ret = pwmchip_add(&ip->chip);
	232	if (ret < 0) {
	233	dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
	234	clk_disable_unprepare(ip->clk);
	235	}
	236
	237	return ret;
	238	}
	239
	240	static int iproc_pwmc_remove(struct platform_device *pdev)
	241	{
	242	struct iproc_pwmc *ip = platform_get_drvdata(pdev);
	243
d4ac3917 UKK	244	pwmchip_remove(&ip->chip);
d4ac3917 UKK	245
daa5abc4 YRDR	246	clk_disable_unprepare(ip->clk);
daa5abc4 YRDR	247
d4ac3917	248	return 0;
daa5abc4 YRDR	249	}
	250
	251	static const struct of_device_id bcm_iproc_pwmc_dt[] = {
	252	{ .compatible = "brcm,iproc-pwm" },
	253	{ },
	254	};
	255	MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);
	256
	257	static struct platform_driver iproc_pwmc_driver = {
	258	.driver = {
	259	.name = "bcm-iproc-pwm",
	260	.of_match_table = bcm_iproc_pwmc_dt,
	261	},
	262	.probe = iproc_pwmc_probe,
	263	.remove = iproc_pwmc_remove,
	264	};
	265	module_platform_driver(iproc_pwmc_driver);
	266
	267	MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
	268	MODULE_DESCRIPTION("Broadcom iProc PWM driver");
	269	MODULE_LICENSE("GPL v2");