[linux-block.git] / drivers / pwm / pwm-ep93xx.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PWM framework driver for Cirrus Logic EP93xx
 *
 * Copyright (c) 2009        Matthieu Crapet <mcrapet@gmail.com>
 * Copyright (c) 2009, 2013  H Hartley Sweeten <hsweeten@visionengravers.com>
 *
 * EP9301/02 have only one channel:
 *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
 *
 * EP9307 has only one channel:
 *   platform device ep93xx-pwm.0 - PWMOUT
 *
 * EP9312/15 have two channels:
 *   platform device ep93xx-pwm.0 - PWMOUT
 *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
 */

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

#include <asm/div64.h>

#include <linux/soc/cirrus/ep93xx.h>	/* for ep93xx_pwm_{acquire,release}_gpio() */

#define EP93XX_PWMx_TERM_COUNT	0x00
#define EP93XX_PWMx_DUTY_CYCLE	0x04
#define EP93XX_PWMx_ENABLE	0x08
#define EP93XX_PWMx_INVERT	0x0c

struct ep93xx_pwm {
	void __iomem *base;
	struct clk *clk;
	struct pwm_chip chip;
};

static inline struct ep93xx_pwm *to_ep93xx_pwm(struct pwm_chip *chip)
{
	return container_of(chip, struct ep93xx_pwm, chip);
}

static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct platform_device *pdev = to_platform_device(chip->dev);

	return ep93xx_pwm_acquire_gpio(pdev);
}

static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct platform_device *pdev = to_platform_device(chip->dev);

	ep93xx_pwm_release_gpio(pdev);
}

static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			     int duty_ns, int period_ns)
{
	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	void __iomem *base = ep93xx_pwm->base;
	unsigned long long c;
	unsigned long period_cycles;
	unsigned long duty_cycles;
	unsigned long term;
	int ret = 0;

	/*
	 * The clock needs to be enabled to access the PWM registers.
	 * Configuration can be changed at any time.
	 */
	if (!pwm_is_enabled(pwm)) {
		ret = clk_enable(ep93xx_pwm->clk);
		if (ret)
			return ret;
	}

	c = clk_get_rate(ep93xx_pwm->clk);
	c *= period_ns;
	do_div(c, 1000000000);
	period_cycles = c;

	c = period_cycles;
	c *= duty_ns;
	do_div(c, period_ns);
	duty_cycles = c;

	if (period_cycles < 0x10000 && duty_cycles < 0x10000) {
		term = readw(base + EP93XX_PWMx_TERM_COUNT);

		/* Order is important if PWM is running */
		if (period_cycles > term) {
			writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
			writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
		} else {
			writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
			writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
		}
	} else {
		ret = -EINVAL;
	}

	if (!pwm_is_enabled(pwm))
		clk_disable(ep93xx_pwm->clk);

	return ret;
}

static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
			       enum pwm_polarity polarity)
{
	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	int ret;

	/*
	 * The clock needs to be enabled to access the PWM registers.
	 * Polarity can only be changed when the PWM is disabled.
	 */
	ret = clk_enable(ep93xx_pwm->clk);
	if (ret)
		return ret;

	if (polarity == PWM_POLARITY_INVERSED)
		writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
	else
		writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);

	clk_disable(ep93xx_pwm->clk);

	return 0;
}

static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	int ret;

	ret = clk_enable(ep93xx_pwm->clk);
	if (ret)
		return ret;

	writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);

	return 0;
}

static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);

	writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
	clk_disable(ep93xx_pwm->clk);
}

static const struct pwm_ops ep93xx_pwm_ops = {
	.request = ep93xx_pwm_request,
	.free = ep93xx_pwm_free,
	.config = ep93xx_pwm_config,
	.set_polarity = ep93xx_pwm_polarity,
	.enable = ep93xx_pwm_enable,
	.disable = ep93xx_pwm_disable,
	.owner = THIS_MODULE,
};

static int ep93xx_pwm_probe(struct platform_device *pdev)
{
	struct ep93xx_pwm *ep93xx_pwm;
	int ret;

	ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
	if (!ep93xx_pwm)
		return -ENOMEM;

	ep93xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(ep93xx_pwm->base))
		return PTR_ERR(ep93xx_pwm->base);

	ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
	if (IS_ERR(ep93xx_pwm->clk))
		return PTR_ERR(ep93xx_pwm->clk);

	ep93xx_pwm->chip.dev = &pdev->dev;
	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
	ep93xx_pwm->chip.npwm = 1;

	ret = pwmchip_add(&ep93xx_pwm->chip);
	if (ret < 0)
		return ret;

	platform_set_drvdata(pdev, ep93xx_pwm);
	return 0;
}

static int ep93xx_pwm_remove(struct platform_device *pdev)
{
	struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);

	return pwmchip_remove(&ep93xx_pwm->chip);
}

static struct platform_driver ep93xx_pwm_driver = {
	.driver = {
		.name = "ep93xx-pwm",
	},
	.probe = ep93xx_pwm_probe,
	.remove = ep93xx_pwm_remove,
};
module_platform_driver(ep93xx_pwm_driver);

MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>");
MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_ALIAS("platform:ep93xx-pwm");
MODULE_LICENSE("GPL");
Commit	Line	Data
c942fddf	1	// SPDX-License-Identifier: GPL-2.0-or-later
a2308698 HS	2	/*
	3	* PWM framework driver for Cirrus Logic EP93xx
	4	*
	5	* Copyright (c) 2009 Matthieu Crapet <mcrapet@gmail.com>
	6	* Copyright (c) 2009, 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
	7	*
	8	* EP9301/02 have only one channel:
	9	* platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
	10	*
	11	* EP9307 has only one channel:
	12	* platform device ep93xx-pwm.0 - PWMOUT
	13	*
	14	* EP9312/15 have two channels:
	15	* platform device ep93xx-pwm.0 - PWMOUT
	16	* platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
a2308698 HS	17	*/
	18
	19	#include <linux/module.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/slab.h>
	22	#include <linux/clk.h>
	23	#include <linux/err.h>
	24	#include <linux/io.h>
	25	#include <linux/pwm.h>
	26
	27	#include <asm/div64.h>
	28
67e38f57	29	#include <linux/soc/cirrus/ep93xx.h> /* for ep93xx_pwm_{acquire,release}_gpio() */
a2308698 HS	30
	31	#define EP93XX_PWMx_TERM_COUNT 0x00
	32	#define EP93XX_PWMx_DUTY_CYCLE 0x04
	33	#define EP93XX_PWMx_ENABLE 0x08
	34	#define EP93XX_PWMx_INVERT 0x0c
	35
	36	struct ep93xx_pwm {
	37	void __iomem *base;
	38	struct clk *clk;
	39	struct pwm_chip chip;
	40	};
	41
	42	static inline struct ep93xx_pwm to_ep93xx_pwm(struct pwm_chip chip)
	43	{
	44	return container_of(chip, struct ep93xx_pwm, chip);
	45	}
	46
	47	static int ep93xx_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	48	{
	49	struct platform_device *pdev = to_platform_device(chip->dev);
	50
	51	return ep93xx_pwm_acquire_gpio(pdev);
	52	}
	53
	54	static void ep93xx_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	55	{
	56	struct platform_device *pdev = to_platform_device(chip->dev);
	57
	58	ep93xx_pwm_release_gpio(pdev);
	59	}
	60
	61	static int ep93xx_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	62	int duty_ns, int period_ns)
	63	{
	64	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	65	void __iomem *base = ep93xx_pwm->base;
	66	unsigned long long c;
	67	unsigned long period_cycles;
	68	unsigned long duty_cycles;
	69	unsigned long term;
	70	int ret = 0;
	71
	72	/*
	73	* The clock needs to be enabled to access the PWM registers.
	74	* Configuration can be changed at any time.
	75	*/
5c31252c	76	if (!pwm_is_enabled(pwm)) {
a2308698 HS	77	ret = clk_enable(ep93xx_pwm->clk);
	78	if (ret)
	79	return ret;
	80	}
	81
	82	c = clk_get_rate(ep93xx_pwm->clk);
	83	c *= period_ns;
	84	do_div(c, 1000000000);
	85	period_cycles = c;
	86
	87	c = period_cycles;
	88	c *= duty_ns;
	89	do_div(c, period_ns);
	90	duty_cycles = c;
	91
	92	if (period_cycles < 0x10000 && duty_cycles < 0x10000) {
	93	term = readw(base + EP93XX_PWMx_TERM_COUNT);
	94
	95	/* Order is important if PWM is running */
	96	if (period_cycles > term) {
	97	writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
	98	writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
	99	} else {
	100	writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);
	101	writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);
	102	}
	103	} else {
	104	ret = -EINVAL;
	105	}
	106
5c31252c	107	if (!pwm_is_enabled(pwm))
a2308698 HS	108	clk_disable(ep93xx_pwm->clk);
	109
	110	return ret;
	111	}
	112
	113	static int ep93xx_pwm_polarity(struct pwm_chip chip, struct pwm_device pwm,
	114	enum pwm_polarity polarity)
	115	{
	116	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	117	int ret;
	118
	119	/*
	120	* The clock needs to be enabled to access the PWM registers.
	121	* Polarity can only be changed when the PWM is disabled.
	122	*/
	123	ret = clk_enable(ep93xx_pwm->clk);
	124	if (ret)
	125	return ret;
	126
	127	if (polarity == PWM_POLARITY_INVERSED)
	128	writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
	129	else
	130	writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);
	131
	132	clk_disable(ep93xx_pwm->clk);
	133
	134	return 0;
	135	}
	136
	137	static int ep93xx_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	138	{
	139	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	140	int ret;
	141
	142	ret = clk_enable(ep93xx_pwm->clk);
	143	if (ret)
	144	return ret;
	145
	146	writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
	147
	148	return 0;
	149	}
	150
	151	static void ep93xx_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
	152	{
	153	struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);
	154
	155	writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);
	156	clk_disable(ep93xx_pwm->clk);
	157	}
	158
	159	static const struct pwm_ops ep93xx_pwm_ops = {
	160	.request = ep93xx_pwm_request,
	161	.free = ep93xx_pwm_free,
	162	.config = ep93xx_pwm_config,
	163	.set_polarity = ep93xx_pwm_polarity,
	164	.enable = ep93xx_pwm_enable,
	165	.disable = ep93xx_pwm_disable,
	166	.owner = THIS_MODULE,
	167	};
	168
	169	static int ep93xx_pwm_probe(struct platform_device *pdev)
	170	{
	171	struct ep93xx_pwm *ep93xx_pwm;
a2308698 HS	172	int ret;
	173
	174	ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);
	175	if (!ep93xx_pwm)
	176	return -ENOMEM;
	177
fc0155f8	178	ep93xx_pwm->base = devm_platform_ioremap_resource(pdev, 0);
a2308698 HS	179	if (IS_ERR(ep93xx_pwm->base))
	180	return PTR_ERR(ep93xx_pwm->base);
	181
	182	ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");
	183	if (IS_ERR(ep93xx_pwm->clk))
	184	return PTR_ERR(ep93xx_pwm->clk);
	185
	186	ep93xx_pwm->chip.dev = &pdev->dev;
	187	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;
a2308698 HS	188	ep93xx_pwm->chip.npwm = 1;
	189
	190	ret = pwmchip_add(&ep93xx_pwm->chip);
	191	if (ret < 0)
	192	return ret;
	193
	194	platform_set_drvdata(pdev, ep93xx_pwm);
	195	return 0;
	196	}
	197
	198	static int ep93xx_pwm_remove(struct platform_device *pdev)
	199	{
	200	struct ep93xx_pwm *ep93xx_pwm = platform_get_drvdata(pdev);
	201
	202	return pwmchip_remove(&ep93xx_pwm->chip);
	203	}
	204
	205	static struct platform_driver ep93xx_pwm_driver = {
	206	.driver = {
	207	.name = "ep93xx-pwm",
	208	},
	209	.probe = ep93xx_pwm_probe,
	210	.remove = ep93xx_pwm_remove,
	211	};
	212	module_platform_driver(ep93xx_pwm_driver);
	213
	214	MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
5eabf82e JH	215	MODULE_AUTHOR("Matthieu Crapet <mcrapet@gmail.com>");
5eabf82e JH	216	MODULE_AUTHOR("H Hartley Sweeten <hsweeten@visionengravers.com>");
a2308698 HS	217	MODULE_ALIAS("platform:ep93xx-pwm");
a2308698 HS	218	MODULE_LICENSE("GPL");