[linux.git] / drivers / pwm / pwm-lpc32xx.c

/*
 * Copyright 2012 Alexandre Pereira da Silva <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.
 *
 */

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

struct lpc32xx_pwm_chip {
	struct pwm_chip chip;
	struct clk *clk;
	void __iomem *base;
};

#define PWM_ENABLE	(1 << 31)
#define PWM_RELOADV(x)	(((x) & 0xFF) << 8)
#define PWM_DUTY(x)	((x) & 0xFF)

#define to_lpc32xx_pwm_chip(_chip) \
	container_of(_chip, struct lpc32xx_pwm_chip, chip)

static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			      int duty_ns, int period_ns)
{
	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
	unsigned long long c;
	int period_cycles, duty_cycles;

	c = clk_get_rate(lpc32xx->clk) / 256;
	c = c * period_ns;
	do_div(c, NSEC_PER_SEC);

	/* Handle high and low extremes */
	if (c == 0)
		c = 1;
	if (c > 255)
		c = 0; /* 0 set division by 256 */
	period_cycles = c;

	c = 256 * duty_ns;
	do_div(c, period_ns);
	duty_cycles = c;

	writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
		lpc32xx->base + (pwm->hwpwm << 2));

	return 0;
}

static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);

	return clk_enable(lpc32xx->clk);
}

static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);

	writel(0, lpc32xx->base + (pwm->hwpwm << 2));
	clk_disable(lpc32xx->clk);
}

static const struct pwm_ops lpc32xx_pwm_ops = {
	.config = lpc32xx_pwm_config,
	.enable = lpc32xx_pwm_enable,
	.disable = lpc32xx_pwm_disable,
	.owner = THIS_MODULE,
};

static int lpc32xx_pwm_probe(struct platform_device *pdev)
{
	struct lpc32xx_pwm_chip *lpc32xx;
	struct resource *res;
	int ret;

	lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
	if (!lpc32xx)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -EINVAL;

	lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res);
	if (!lpc32xx->base)
		return -EADDRNOTAVAIL;

	lpc32xx->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(lpc32xx->clk))
		return PTR_ERR(lpc32xx->clk);

	lpc32xx->chip.dev = &pdev->dev;
	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
	lpc32xx->chip.npwm = 2;

	ret = pwmchip_add(&lpc32xx->chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, lpc32xx);

	return 0;
}

static int __devexit lpc32xx_pwm_remove(struct platform_device *pdev)
{
	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);

	clk_disable(lpc32xx->clk);
	return pwmchip_remove(&lpc32xx->chip);
}

static struct of_device_id lpc32xx_pwm_dt_ids[] = {
	{ .compatible = "nxp,lpc3220-pwm", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);

static struct platform_driver lpc32xx_pwm_driver = {
	.driver = {
		.name = "lpc32xx-pwm",
		.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
	},
	.probe = lpc32xx_pwm_probe,
	.remove = __devexit_p(lpc32xx_pwm_remove),
};
module_platform_driver(lpc32xx_pwm_driver);

MODULE_ALIAS("platform:lpc32xx-pwm");
MODULE_AUTHOR("Alexandre Pereira da Silva <[email protected]>");
MODULE_DESCRIPTION("LPC32XX PWM Driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2132fa8d APS	1	/*
	2	* Copyright 2012 Alexandre Pereira da Silva <[email protected]>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; version 2.
	7	*
	8	*/
	9
	10	#include <linux/clk.h>
	11	#include <linux/err.h>
	12	#include <linux/io.h>
	13	#include <linux/kernel.h>
	14	#include <linux/module.h>
	15	#include <linux/of.h>
	16	#include <linux/of_address.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/pwm.h>
	19	#include <linux/slab.h>
	20
	21	struct lpc32xx_pwm_chip {
	22	struct pwm_chip chip;
	23	struct clk *clk;
	24	void __iomem *base;
	25	};
	26
	27	#define PWM_ENABLE (1 << 31)
	28	#define PWM_RELOADV(x) (((x) & 0xFF) << 8)
	29	#define PWM_DUTY(x) ((x) & 0xFF)
	30
	31	#define to_lpc32xx_pwm_chip(_chip) \
	32	container_of(_chip, struct lpc32xx_pwm_chip, chip)
	33
	34	static int lpc32xx_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
	35	int duty_ns, int period_ns)
	36	{
	37	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
	38	unsigned long long c;
	39	int period_cycles, duty_cycles;
	40
	41	c = clk_get_rate(lpc32xx->clk) / 256;
	42	c = c * period_ns;
	43	do_div(c, NSEC_PER_SEC);
	44
	45	/* Handle high and low extremes */
	46	if (c == 0)
	47	c = 1;
	48	if (c > 255)
	49	c = 0; /* 0 set division by 256 */
	50	period_cycles = c;
	51
	52	c = 256 * duty_ns;
	53	do_div(c, period_ns);
	54	duty_cycles = c;
	55
	56	writel(PWM_ENABLE \| PWM_RELOADV(period_cycles) \| PWM_DUTY(duty_cycles),
	57	lpc32xx->base + (pwm->hwpwm << 2));
	58
	59	return 0;
	60	}
	61
	62	static int lpc32xx_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
	63	{
	64	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
65
66	return clk_enable(lpc32xx->clk);
67	}
68
69	static void lpc32xx_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
70	{
71	struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip);
72
73	writel(0, lpc32xx->base + (pwm->hwpwm << 2));
74	clk_disable(lpc32xx->clk);
75	}
76
77	static const struct pwm_ops lpc32xx_pwm_ops = {
78	.config = lpc32xx_pwm_config,
79	.enable = lpc32xx_pwm_enable,
80	.disable = lpc32xx_pwm_disable,
81	.owner = THIS_MODULE,
82	};
83
84	static int lpc32xx_pwm_probe(struct platform_device *pdev)
85	{
86	struct lpc32xx_pwm_chip *lpc32xx;
87	struct resource *res;
88	int ret;
89
90	lpc32xx = devm_kzalloc(&pdev->dev, sizeof(*lpc32xx), GFP_KERNEL);
91	if (!lpc32xx)
92	return -ENOMEM;
93
94	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
95	if (!res)
96	return -EINVAL;
97
98	lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res);
99	if (!lpc32xx->base)
100	return -EADDRNOTAVAIL;
101
102	lpc32xx->clk = devm_clk_get(&pdev->dev, NULL);
103	if (IS_ERR(lpc32xx->clk))
104	return PTR_ERR(lpc32xx->clk);
105
106	lpc32xx->chip.dev = &pdev->dev;
107	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
108	lpc32xx->chip.npwm = 2;
109
110	ret = pwmchip_add(&lpc32xx->chip);
111	if (ret < 0) {
112	dev_err(&pdev->dev, "failed to add PWM chip, error %d\n", ret);
113	return ret;
114	}
115
116	platform_set_drvdata(pdev, lpc32xx);
117
118	return 0;
119	}
120
121	static int __devexit lpc32xx_pwm_remove(struct platform_device *pdev)
122	{
123	struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev);
124
125	clk_disable(lpc32xx->clk);
126	return pwmchip_remove(&lpc32xx->chip);
127	}
128
129	static struct of_device_id lpc32xx_pwm_dt_ids[] = {
130	{ .compatible = "nxp,lpc3220-pwm", },
131	{ /* sentinel */ }
132	};
133	MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids);
134
135	static struct platform_driver lpc32xx_pwm_driver = {
136	.driver = {
137	.name = "lpc32xx-pwm",
138	.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
139	},
140	.probe = lpc32xx_pwm_probe,
141	.remove = __devexit_p(lpc32xx_pwm_remove),
142	};
143	module_platform_driver(lpc32xx_pwm_driver);
144
145	MODULE_ALIAS("platform:lpc32xx-pwm");
146	MODULE_AUTHOR("Alexandre Pereira da Silva <[email protected]>");
147	MODULE_DESCRIPTION("LPC32XX PWM Driver");
148	MODULE_LICENSE("GPL v2");