[linux-2.6-block.git] / drivers / pwm / pwm-berlin.c

/*
 * Marvell Berlin PWM driver
 *
 * Copyright (C) 2015 Marvell Technology Group Ltd.
 *
 * Author: Antoine Tenart <antoine.tenart@free-electrons.com>
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

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

#define BERLIN_PWM_EN			0x0
#define  BERLIN_PWM_ENABLE		BIT(0)
#define BERLIN_PWM_CONTROL		0x4
/*
 * The prescaler claims to support 8 different moduli, configured using the
 * low three bits of PWM_CONTROL. (Sequentially, they are 1, 4, 8, 16, 64,
 * 256, 1024, and 4096.)  However, the moduli from 4 to 1024 appear to be
 * implemented by internally shifting TCNT left without adding additional
 * bits. So, the max TCNT that actually works for a modulus of 4 is 0x3fff;
 * for 8, 0x1fff; and so on. This means that those moduli are entirely
 * useless, as we could just do the shift ourselves. The 4096 modulus is
 * implemented with a real prescaler, so we do use that, but we treat it
 * as a flag instead of pretending the modulus is actually configurable.
 */
#define  BERLIN_PWM_PRESCALE_4096	0x7
#define  BERLIN_PWM_INVERT_POLARITY	BIT(3)
#define BERLIN_PWM_DUTY			0x8
#define BERLIN_PWM_TCNT			0xc
#define  BERLIN_PWM_MAX_TCNT		65535

struct berlin_pwm_channel {
	u32 enable;
	u32 ctrl;
	u32 duty;
	u32 tcnt;
};

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

static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip)
{
	return container_of(chip, struct berlin_pwm_chip, chip);
}

static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
				   unsigned int channel, unsigned long offset)
{
	return readl_relaxed(chip->base + channel * 0x10 + offset);
}

static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
				     unsigned int channel, u32 value,
				     unsigned long offset)
{
	writel_relaxed(value, chip->base + channel * 0x10 + offset);
}

static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct berlin_pwm_channel *channel;

	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	if (!channel)
		return -ENOMEM;

	return pwm_set_chip_data(pwm, channel);
}

static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);

	pwm_set_chip_data(pwm, NULL);
	kfree(channel);
}

static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm_dev,
			     int duty_ns, int period_ns)
{
	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	bool prescale_4096 = false;
	u32 value, duty, period;
	u64 cycles;

	cycles = clk_get_rate(pwm->clk);
	cycles *= period_ns;
	do_div(cycles, NSEC_PER_SEC);

	if (cycles > BERLIN_PWM_MAX_TCNT) {
		prescale_4096 = true;
		cycles >>= 12; // Prescaled by 4096

		if (cycles > BERLIN_PWM_MAX_TCNT)
			return -ERANGE;
	}

	period = cycles;
	cycles *= duty_ns;
	do_div(cycles, period_ns);
	duty = cycles;

	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
	if (prescale_4096)
		value |= BERLIN_PWM_PRESCALE_4096;
	else
		value &= ~BERLIN_PWM_PRESCALE_4096;
	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);

	berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
	berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);

	return 0;
}

static int berlin_pwm_set_polarity(struct pwm_chip *chip,
				   struct pwm_device *pwm_dev,
				   enum pwm_polarity polarity)
{
	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	u32 value;

	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);

	if (polarity == PWM_POLARITY_NORMAL)
		value &= ~BERLIN_PWM_INVERT_POLARITY;
	else
		value |= BERLIN_PWM_INVERT_POLARITY;

	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);

	return 0;
}

static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm_dev)
{
	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	u32 value;

	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
	value |= BERLIN_PWM_ENABLE;
	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);

	return 0;
}

static void berlin_pwm_disable(struct pwm_chip *chip,
			       struct pwm_device *pwm_dev)
{
	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	u32 value;

	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
	value &= ~BERLIN_PWM_ENABLE;
	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
}

static const struct pwm_ops berlin_pwm_ops = {
	.request = berlin_pwm_request,
	.free = berlin_pwm_free,
	.config = berlin_pwm_config,
	.set_polarity = berlin_pwm_set_polarity,
	.enable = berlin_pwm_enable,
	.disable = berlin_pwm_disable,
	.owner = THIS_MODULE,
};

static const struct of_device_id berlin_pwm_match[] = {
	{ .compatible = "marvell,berlin-pwm" },
	{ },
};
MODULE_DEVICE_TABLE(of, berlin_pwm_match);

static int berlin_pwm_probe(struct platform_device *pdev)
{
	struct berlin_pwm_chip *pwm;
	struct resource *res;
	int ret;

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

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	pwm->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(pwm->base))
		return PTR_ERR(pwm->base);

	pwm->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(pwm->clk))
		return PTR_ERR(pwm->clk);

	ret = clk_prepare_enable(pwm->clk);
	if (ret)
		return ret;

	pwm->chip.dev = &pdev->dev;
	pwm->chip.ops = &berlin_pwm_ops;
	pwm->chip.base = -1;
	pwm->chip.npwm = 4;
	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
	pwm->chip.of_pwm_n_cells = 3;

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

	platform_set_drvdata(pdev, pwm);

	return 0;
}

static int berlin_pwm_remove(struct platform_device *pdev)
{
	struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
	int ret;

	ret = pwmchip_remove(&pwm->chip);
	clk_disable_unprepare(pwm->clk);

	return ret;
}

#ifdef CONFIG_PM_SLEEP
static int berlin_pwm_suspend(struct device *dev)
{
	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
	unsigned int i;

	for (i = 0; i < pwm->chip.npwm; i++) {
		struct berlin_pwm_channel *channel;

		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
		if (!channel)
			continue;

		channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
		channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
		channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
		channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
	}

	clk_disable_unprepare(pwm->clk);

	return 0;
}

static int berlin_pwm_resume(struct device *dev)
{
	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
	unsigned int i;
	int ret;

	ret = clk_prepare_enable(pwm->clk);
	if (ret)
		return ret;

	for (i = 0; i < pwm->chip.npwm; i++) {
		struct berlin_pwm_channel *channel;

		channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
		if (!channel)
			continue;

		berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
		berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
		berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
		berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
	}

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
			 berlin_pwm_resume);

static struct platform_driver berlin_pwm_driver = {
	.probe = berlin_pwm_probe,
	.remove = berlin_pwm_remove,
	.driver = {
		.name = "berlin-pwm",
		.of_match_table = berlin_pwm_match,
		.pm = &berlin_pwm_pm_ops,
	},
};
module_platform_driver(berlin_pwm_driver);

MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
MODULE_DESCRIPTION("Marvell Berlin PWM driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
59d5c8b1 AT	1	/*
	2	* Marvell Berlin PWM driver
	3	*
	4	* Copyright (C) 2015 Marvell Technology Group Ltd.
	5	*
	6	* Author: Antoine Tenart <antoine.tenart@free-electrons.com>
	7	*
	8	* This file is licensed under the terms of the GNU General Public
	9	* License version 2. This program is licensed "as is" without any
	10	* warranty of any kind, whether express or implied.
	11	*/
	12
	13	#include <linux/clk.h>
	14	#include <linux/io.h>
	15	#include <linux/kernel.h>
	16	#include <linux/module.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/pwm.h>
bbf0722c	19	#include <linux/slab.h>
59d5c8b1 AT	20
	21	#define BERLIN_PWM_EN 0x0
	22	#define BERLIN_PWM_ENABLE BIT(0)
	23	#define BERLIN_PWM_CONTROL 0x4
4de445cb TH	24	/*
	25	* The prescaler claims to support 8 different moduli, configured using the
	26	* low three bits of PWM_CONTROL. (Sequentially, they are 1, 4, 8, 16, 64,
	27	* 256, 1024, and 4096.) However, the moduli from 4 to 1024 appear to be
	28	* implemented by internally shifting TCNT left without adding additional
	29	* bits. So, the max TCNT that actually works for a modulus of 4 is 0x3fff;
	30	* for 8, 0x1fff; and so on. This means that those moduli are entirely
	31	* useless, as we could just do the shift ourselves. The 4096 modulus is
	32	* implemented with a real prescaler, so we do use that, but we treat it
	33	* as a flag instead of pretending the modulus is actually configurable.
	34	*/
	35	#define BERLIN_PWM_PRESCALE_4096 0x7
59d5c8b1 AT	36	#define BERLIN_PWM_INVERT_POLARITY BIT(3)
	37	#define BERLIN_PWM_DUTY 0x8
	38	#define BERLIN_PWM_TCNT 0xc
	39	#define BERLIN_PWM_MAX_TCNT 65535
	40
bbf0722c JZ	41	struct berlin_pwm_channel {
	42	u32 enable;
	43	u32 ctrl;
	44	u32 duty;
	45	u32 tcnt;
	46	};
	47
59d5c8b1 AT	48	struct berlin_pwm_chip {
	49	struct pwm_chip chip;
	50	struct clk *clk;
	51	void __iomem *base;
	52	};
	53
	54	static inline struct berlin_pwm_chip to_berlin_pwm_chip(struct pwm_chip chip)
	55	{
	56	return container_of(chip, struct berlin_pwm_chip, chip);
	57	}
	58
59d5c8b1 AT	59	static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *chip,
	60	unsigned int channel, unsigned long offset)
	61	{
	62	return readl_relaxed(chip->base + channel * 0x10 + offset);
	63	}
	64
	65	static inline void berlin_pwm_writel(struct berlin_pwm_chip *chip,
	66	unsigned int channel, u32 value,
	67	unsigned long offset)
	68	{
	69	writel_relaxed(value, chip->base + channel * 0x10 + offset);
	70	}
	71
bbf0722c JZ	72	static int berlin_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	73	{
	74	struct berlin_pwm_channel *channel;
	75
	76	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	77	if (!channel)
	78	return -ENOMEM;
	79
	80	return pwm_set_chip_data(pwm, channel);
	81	}
	82
	83	static void berlin_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
	84	{
	85	struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm);
	86
	87	pwm_set_chip_data(pwm, NULL);
	88	kfree(channel);
	89	}
	90
59d5c8b1 AT	91	static int berlin_pwm_config(struct pwm_chip chip, struct pwm_device pwm_dev,
	92	int duty_ns, int period_ns)
	93	{
	94	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
4de445cb	95	bool prescale_4096 = false;
59d5c8b1	96	u32 value, duty, period;
4de445cb	97	u64 cycles;
59d5c8b1 AT	98
	99	cycles = clk_get_rate(pwm->clk);
	100	cycles *= period_ns;
	101	do_div(cycles, NSEC_PER_SEC);
	102
4de445cb TH	103	if (cycles > BERLIN_PWM_MAX_TCNT) {
	104	prescale_4096 = true;
	105	cycles >>= 12; // Prescaled by 4096
59d5c8b1	106
4de445cb TH	107	if (cycles > BERLIN_PWM_MAX_TCNT)
4de445cb TH	108	return -ERANGE;
59d5c8b1 AT	109	}
59d5c8b1 AT	110
4de445cb TH	111	period = cycles;
4de445cb TH	112	cycles *= duty_ns;
59d5c8b1 AT	113	do_div(cycles, period_ns);
	114	duty = cycles;
	115
	116	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
4de445cb TH	117	if (prescale_4096)
	118	value \|= BERLIN_PWM_PRESCALE_4096;
	119	else
	120	value &= ~BERLIN_PWM_PRESCALE_4096;
59d5c8b1 AT	121	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
	122
	123	berlin_pwm_writel(pwm, pwm_dev->hwpwm, duty, BERLIN_PWM_DUTY);
	124	berlin_pwm_writel(pwm, pwm_dev->hwpwm, period, BERLIN_PWM_TCNT);
	125
	126	return 0;
	127	}
	128
	129	static int berlin_pwm_set_polarity(struct pwm_chip *chip,
	130	struct pwm_device *pwm_dev,
	131	enum pwm_polarity polarity)
	132	{
	133	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	134	u32 value;
	135
	136	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_CONTROL);
	137
	138	if (polarity == PWM_POLARITY_NORMAL)
	139	value &= ~BERLIN_PWM_INVERT_POLARITY;
	140	else
	141	value \|= BERLIN_PWM_INVERT_POLARITY;
	142
	143	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_CONTROL);
	144
	145	return 0;
	146	}
	147
	148	static int berlin_pwm_enable(struct pwm_chip chip, struct pwm_device pwm_dev)
	149	{
	150	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	151	u32 value;
	152
	153	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
	154	value \|= BERLIN_PWM_ENABLE;
	155	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
	156
	157	return 0;
	158	}
	159
	160	static void berlin_pwm_disable(struct pwm_chip *chip,
	161	struct pwm_device *pwm_dev)
	162	{
	163	struct berlin_pwm_chip *pwm = to_berlin_pwm_chip(chip);
	164	u32 value;
	165
	166	value = berlin_pwm_readl(pwm, pwm_dev->hwpwm, BERLIN_PWM_EN);
	167	value &= ~BERLIN_PWM_ENABLE;
	168	berlin_pwm_writel(pwm, pwm_dev->hwpwm, value, BERLIN_PWM_EN);
	169	}
	170
	171	static const struct pwm_ops berlin_pwm_ops = {
bbf0722c JZ	172	.request = berlin_pwm_request,
bbf0722c JZ	173	.free = berlin_pwm_free,
59d5c8b1 AT	174	.config = berlin_pwm_config,
	175	.set_polarity = berlin_pwm_set_polarity,
	176	.enable = berlin_pwm_enable,
	177	.disable = berlin_pwm_disable,
	178	.owner = THIS_MODULE,
	179	};
	180
	181	static const struct of_device_id berlin_pwm_match[] = {
	182	{ .compatible = "marvell,berlin-pwm" },
	183	{ },
	184	};
	185	MODULE_DEVICE_TABLE(of, berlin_pwm_match);
	186
	187	static int berlin_pwm_probe(struct platform_device *pdev)
	188	{
	189	struct berlin_pwm_chip *pwm;
	190	struct resource *res;
	191	int ret;
	192
	193	pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
	194	if (!pwm)
	195	return -ENOMEM;
	196
	197	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	198	pwm->base = devm_ioremap_resource(&pdev->dev, res);
	199	if (IS_ERR(pwm->base))
	200	return PTR_ERR(pwm->base);
	201
	202	pwm->clk = devm_clk_get(&pdev->dev, NULL);
	203	if (IS_ERR(pwm->clk))
	204	return PTR_ERR(pwm->clk);
	205
	206	ret = clk_prepare_enable(pwm->clk);
	207	if (ret)
	208	return ret;
	209
	210	pwm->chip.dev = &pdev->dev;
	211	pwm->chip.ops = &berlin_pwm_ops;
	212	pwm->chip.base = -1;
	213	pwm->chip.npwm = 4;
59d5c8b1 AT	214	pwm->chip.of_xlate = of_pwm_xlate_with_flags;
	215	pwm->chip.of_pwm_n_cells = 3;
	216
	217	ret = pwmchip_add(&pwm->chip);
	218	if (ret < 0) {
	219	dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
	220	clk_disable_unprepare(pwm->clk);
	221	return ret;
	222	}
	223
	224	platform_set_drvdata(pdev, pwm);
	225
	226	return 0;
	227	}
	228
	229	static int berlin_pwm_remove(struct platform_device *pdev)
	230	{
	231	struct berlin_pwm_chip *pwm = platform_get_drvdata(pdev);
	232	int ret;
	233
	234	ret = pwmchip_remove(&pwm->chip);
	235	clk_disable_unprepare(pwm->clk);
	236
	237	return ret;
	238	}
	239
bbf0722c JZ	240	#ifdef CONFIG_PM_SLEEP
	241	static int berlin_pwm_suspend(struct device *dev)
	242	{
	243	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
	244	unsigned int i;
	245
	246	for (i = 0; i < pwm->chip.npwm; i++) {
	247	struct berlin_pwm_channel *channel;
	248
	249	channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
	250	if (!channel)
	251	continue;
	252
	253	channel->enable = berlin_pwm_readl(pwm, i, BERLIN_PWM_ENABLE);
	254	channel->ctrl = berlin_pwm_readl(pwm, i, BERLIN_PWM_CONTROL);
	255	channel->duty = berlin_pwm_readl(pwm, i, BERLIN_PWM_DUTY);
	256	channel->tcnt = berlin_pwm_readl(pwm, i, BERLIN_PWM_TCNT);
	257	}
	258
	259	clk_disable_unprepare(pwm->clk);
	260
	261	return 0;
	262	}
	263
	264	static int berlin_pwm_resume(struct device *dev)
	265	{
	266	struct berlin_pwm_chip *pwm = dev_get_drvdata(dev);
	267	unsigned int i;
	268	int ret;
	269
	270	ret = clk_prepare_enable(pwm->clk);
	271	if (ret)
	272	return ret;
	273
	274	for (i = 0; i < pwm->chip.npwm; i++) {
	275	struct berlin_pwm_channel *channel;
	276
	277	channel = pwm_get_chip_data(&pwm->chip.pwms[i]);
	278	if (!channel)
	279	continue;
	280
	281	berlin_pwm_writel(pwm, i, channel->ctrl, BERLIN_PWM_CONTROL);
	282	berlin_pwm_writel(pwm, i, channel->duty, BERLIN_PWM_DUTY);
	283	berlin_pwm_writel(pwm, i, channel->tcnt, BERLIN_PWM_TCNT);
	284	berlin_pwm_writel(pwm, i, channel->enable, BERLIN_PWM_ENABLE);
	285	}
	286
	287	return 0;
	288	}
	289	#endif
	290
	291	static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend,
	292	berlin_pwm_resume);
	293
59d5c8b1 AT	294	static struct platform_driver berlin_pwm_driver = {
	295	.probe = berlin_pwm_probe,
	296	.remove = berlin_pwm_remove,
	297	.driver = {
	298	.name = "berlin-pwm",
	299	.of_match_table = berlin_pwm_match,
bbf0722c	300	.pm = &berlin_pwm_pm_ops,
59d5c8b1 AT	301	},
	302	};
	303	module_platform_driver(berlin_pwm_driver);
	304
	305	MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>");
	306	MODULE_DESCRIPTION("Marvell Berlin PWM driver");
	307	MODULE_LICENSE("GPL v2");