[linux-2.6-block.git] / drivers / pwm / pwm-jz4740.c

/*
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 *  JZ4740 platform PWM support
 *
 *  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;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/clk.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>

#include <asm/mach-jz4740/gpio.h>
#include <asm/mach-jz4740/timer.h>

#define NUM_PWM 8

static const unsigned int jz4740_pwm_gpio_list[NUM_PWM] = {
	JZ_GPIO_PWM0,
	JZ_GPIO_PWM1,
	JZ_GPIO_PWM2,
	JZ_GPIO_PWM3,
	JZ_GPIO_PWM4,
	JZ_GPIO_PWM5,
	JZ_GPIO_PWM6,
	JZ_GPIO_PWM7,
};

struct jz4740_pwm_chip {
	struct pwm_chip chip;
	struct clk *clk;
};

static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
{
	return container_of(chip, struct jz4740_pwm_chip, chip);
}

static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
{
	unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];
	int ret;

	/*
	 * Timers 0 and 1 are used for system tasks, so they are unavailable
	 * for use as PWMs.
	 */
	if (pwm->hwpwm < 2)
		return -EBUSY;

	ret = gpio_request(gpio, pwm->label);
	if (ret) {
		dev_err(chip->dev, "Failed to request GPIO#%u for PWM: %d\n",
			gpio, ret);
		return ret;
	}

	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_PWM);

	jz4740_timer_start(pwm->hwpwm);

	return 0;
}

static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
	unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];

	jz4740_timer_set_ctrl(pwm->hwpwm, 0);

	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_NONE);
	gpio_free(gpio);

	jz4740_timer_stop(pwm->hwpwm);
}

static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);

	ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
	jz4740_timer_enable(pwm->hwpwm);

	return 0;
}

static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);

	ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
	jz4740_timer_disable(pwm->hwpwm);
	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
}

static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
			     int duty_ns, int period_ns)
{
	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
	unsigned long long tmp;
	unsigned long period, duty;
	unsigned int prescaler = 0;
	uint16_t ctrl;
	bool is_enabled;

	tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
	do_div(tmp, 1000000000);
	period = tmp;

	while (period > 0xffff && prescaler < 6) {
		period >>= 2;
		++prescaler;
	}

	if (prescaler == 6)
		return -EINVAL;

	tmp = (unsigned long long)period * duty_ns;
	do_div(tmp, period_ns);
	duty = period - tmp;

	if (duty >= period)
		duty = period - 1;

	is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
	if (is_enabled)
		jz4740_pwm_disable(chip, pwm);

	jz4740_timer_set_count(pwm->hwpwm, 0);
	jz4740_timer_set_duty(pwm->hwpwm, duty);
	jz4740_timer_set_period(pwm->hwpwm, period);

	ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
		JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;

	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);

	if (is_enabled)
		jz4740_pwm_enable(chip, pwm);

	return 0;
}

static const struct pwm_ops jz4740_pwm_ops = {
	.request = jz4740_pwm_request,
	.free = jz4740_pwm_free,
	.config = jz4740_pwm_config,
	.enable = jz4740_pwm_enable,
	.disable = jz4740_pwm_disable,
	.owner = THIS_MODULE,
};

static int jz4740_pwm_probe(struct platform_device *pdev)
{
	struct jz4740_pwm_chip *jz4740;

	jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
	if (!jz4740)
		return -ENOMEM;

	jz4740->clk = devm_clk_get(&pdev->dev, "ext");
	if (IS_ERR(jz4740->clk))
		return PTR_ERR(jz4740->clk);

	jz4740->chip.dev = &pdev->dev;
	jz4740->chip.ops = &jz4740_pwm_ops;
	jz4740->chip.npwm = NUM_PWM;
	jz4740->chip.base = -1;

	platform_set_drvdata(pdev, jz4740);

	return pwmchip_add(&jz4740->chip);
}

static int jz4740_pwm_remove(struct platform_device *pdev)
{
	struct jz4740_pwm_chip *jz4740 = platform_get_drvdata(pdev);

	return pwmchip_remove(&jz4740->chip);
}

static struct platform_driver jz4740_pwm_driver = {
	.driver = {
		.name = "jz4740-pwm",
	},
	.probe = jz4740_pwm_probe,
	.remove = jz4740_pwm_remove,
};
module_platform_driver(jz4740_pwm_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Ingenic JZ4740 PWM driver");
MODULE_ALIAS("platform:jz4740-pwm");
MODULE_LICENSE("GPL");
Commit	Line	Data
f6b8a570 TR	1	/*
	2	* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
	3	* JZ4740 platform PWM support
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License as published by the
	7	* Free Software Foundation; either version 2 of the License, or (at your
	8	* option) any later version.
	9	*
	10	* You should have received a copy of the GNU General Public License along
	11	* with this program; if not, write to the Free Software Foundation, Inc.,
	12	* 675 Mass Ave, Cambridge, MA 02139, USA.
	13	*
	14	*/
	15
	16	#include <linux/clk.h>
	17	#include <linux/err.h>
	18	#include <linux/gpio.h>
	19	#include <linux/kernel.h>
	20	#include <linux/module.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/pwm.h>
	23
	24	#include <asm/mach-jz4740/gpio.h>
	25	#include <asm/mach-jz4740/timer.h>
	26
	27	#define NUM_PWM 8
	28
	29	static const unsigned int jz4740_pwm_gpio_list[NUM_PWM] = {
	30	JZ_GPIO_PWM0,
	31	JZ_GPIO_PWM1,
	32	JZ_GPIO_PWM2,
	33	JZ_GPIO_PWM3,
	34	JZ_GPIO_PWM4,
	35	JZ_GPIO_PWM5,
	36	JZ_GPIO_PWM6,
	37	JZ_GPIO_PWM7,
	38	};
	39
	40	struct jz4740_pwm_chip {
	41	struct pwm_chip chip;
	42	struct clk *clk;
	43	};
	44
	45	static inline struct jz4740_pwm_chip to_jz4740(struct pwm_chip chip)
	46	{
	47	return container_of(chip, struct jz4740_pwm_chip, chip);
	48	}
	49
	50	static int jz4740_pwm_request(struct pwm_chip chip, struct pwm_device pwm)
	51	{
	52	unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];
	53	int ret;
	54
	55	/*
	56	* Timers 0 and 1 are used for system tasks, so they are unavailable
	57	* for use as PWMs.
	58	*/
	59	if (pwm->hwpwm < 2)
	60	return -EBUSY;
	61
	62	ret = gpio_request(gpio, pwm->label);
	63	if (ret) {
	64	dev_err(chip->dev, "Failed to request GPIO#%u for PWM: %d\n",
65	gpio, ret);
66	return ret;
67	}
68
69	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_PWM);
70
71	jz4740_timer_start(pwm->hwpwm);
72
73	return 0;
74	}
75
76	static void jz4740_pwm_free(struct pwm_chip chip, struct pwm_device pwm)
77	{
78	unsigned int gpio = jz4740_pwm_gpio_list[pwm->hwpwm];
79
80	jz4740_timer_set_ctrl(pwm->hwpwm, 0);
81
82	jz_gpio_set_function(gpio, JZ_GPIO_FUNC_NONE);
83	gpio_free(gpio);
84
85	jz4740_timer_stop(pwm->hwpwm);
86	}
87
88	static int jz4740_pwm_enable(struct pwm_chip chip, struct pwm_device pwm)
89	{
90	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
91
92	ctrl \|= JZ_TIMER_CTRL_PWM_ENABLE;
93	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
94	jz4740_timer_enable(pwm->hwpwm);
95
96	return 0;
97	}
98
99	static void jz4740_pwm_disable(struct pwm_chip chip, struct pwm_device pwm)
100	{
101	uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
102
103	ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
104	jz4740_timer_disable(pwm->hwpwm);
105	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
106	}
107
108	static int jz4740_pwm_config(struct pwm_chip chip, struct pwm_device pwm,
109	int duty_ns, int period_ns)
110	{
111	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
112	unsigned long long tmp;
113	unsigned long period, duty;
114	unsigned int prescaler = 0;
115	uint16_t ctrl;
116	bool is_enabled;
117
118	tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
119	do_div(tmp, 1000000000);
120	period = tmp;
121
122	while (period > 0xffff && prescaler < 6) {
123	period >>= 2;
124	++prescaler;
125	}
126
127	if (prescaler == 6)
128	return -EINVAL;
129
130	tmp = (unsigned long long)period * duty_ns;
131	do_div(tmp, period_ns);
132	duty = period - tmp;
133
134	if (duty >= period)
135	duty = period - 1;
136
137	is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
138	if (is_enabled)
139	jz4740_pwm_disable(chip, pwm);
140
141	jz4740_timer_set_count(pwm->hwpwm, 0);
142	jz4740_timer_set_duty(pwm->hwpwm, duty);
143	jz4740_timer_set_period(pwm->hwpwm, period);
144
145	ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) \| JZ_TIMER_CTRL_SRC_EXT \|
146	JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
147
148	jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
149
150	if (is_enabled)
151	jz4740_pwm_enable(chip, pwm);
152
153	return 0;
154	}
155
156	static const struct pwm_ops jz4740_pwm_ops = {
157	.request = jz4740_pwm_request,
158	.free = jz4740_pwm_free,
159	.config = jz4740_pwm_config,
160	.enable = jz4740_pwm_enable,
161	.disable = jz4740_pwm_disable,
162	.owner = THIS_MODULE,
163	};
164
3e9fe83d	165	static int jz4740_pwm_probe(struct platform_device *pdev)
f6b8a570 TR	166	{
f6b8a570 TR	167	struct jz4740_pwm_chip *jz4740;
f6b8a570 TR	168
	169	jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
	170	if (!jz4740)
	171	return -ENOMEM;
	172
0dc1135f	173	jz4740->clk = devm_clk_get(&pdev->dev, "ext");
f6b8a570 TR	174	if (IS_ERR(jz4740->clk))
	175	return PTR_ERR(jz4740->clk);
	176
	177	jz4740->chip.dev = &pdev->dev;
	178	jz4740->chip.ops = &jz4740_pwm_ops;
	179	jz4740->chip.npwm = NUM_PWM;
	180	jz4740->chip.base = -1;
	181
f6b8a570 TR	182	platform_set_drvdata(pdev, jz4740);
f6b8a570 TR	183
0dc1135f	184	return pwmchip_add(&jz4740->chip);
f6b8a570 TR	185	}
f6b8a570 TR	186
77f37917	187	static int jz4740_pwm_remove(struct platform_device *pdev)
f6b8a570 TR	188	{
f6b8a570 TR	189	struct jz4740_pwm_chip *jz4740 = platform_get_drvdata(pdev);
f6b8a570	190
0dc1135f	191	return pwmchip_remove(&jz4740->chip);
f6b8a570 TR	192	}
	193
	194	static struct platform_driver jz4740_pwm_driver = {
	195	.driver = {
	196	.name = "jz4740-pwm",
f6b8a570 TR	197	},
f6b8a570 TR	198	.probe = jz4740_pwm_probe,
fd109112	199	.remove = jz4740_pwm_remove,
f6b8a570 TR	200	};
	201	module_platform_driver(jz4740_pwm_driver);
	202
	203	MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
	204	MODULE_DESCRIPTION("Ingenic JZ4740 PWM driver");
	205	MODULE_ALIAS("platform:jz4740-pwm");
	206	MODULE_LICENSE("GPL");