[linux.git] / drivers / misc / ab8500-pwm.c

/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * Author: Arun R Murthy <[email protected]>
 * License terms: GNU General Public License (GPL) version 2
 */
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/pwm.h>
#include <linux/mfd/ab8500.h>
#include <linux/mfd/abx500.h>

/*
 * PWM Out generators
 * Bank: 0x10
 */
#define AB8500_PWM_OUT_CTRL1_REG	0x60
#define AB8500_PWM_OUT_CTRL2_REG	0x61
#define AB8500_PWM_OUT_CTRL7_REG	0x66

/* backlight driver constants */
#define ENABLE_PWM			1
#define DISABLE_PWM			0

struct pwm_device {
	struct device *dev;
	struct list_head node;
	const char *label;
	unsigned int pwm_id;
};

static LIST_HEAD(pwm_list);

int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
	int ret = 0;
	unsigned int higher_val, lower_val;
	u8 reg;

	/*
	 * get the first 8 bits that are be written to
	 * AB8500_PWM_OUT_CTRL1_REG[0:7]
	 */
	lower_val = duty_ns & 0x00FF;
	/*
	 * get bits [9:10] that are to be written to
	 * AB8500_PWM_OUT_CTRL2_REG[0:1]
	 */
	higher_val = ((duty_ns & 0x0300) >> 8);

	reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);

	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
			reg, (u8)lower_val);
	if (ret < 0)
		return ret;
	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
			(reg + 1), (u8)higher_val);

	return ret;
}
EXPORT_SYMBOL(pwm_config);

int pwm_enable(struct pwm_device *pwm)
{
	int ret;

	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
				1 << (pwm->pwm_id-1), ENABLE_PWM);
	if (ret < 0)
		dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
							pwm->label, ret);
	return ret;
}
EXPORT_SYMBOL(pwm_enable);

void pwm_disable(struct pwm_device *pwm)
{
	int ret;

	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
				1 << (pwm->pwm_id-1), DISABLE_PWM);
	if (ret < 0)
		dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
							pwm->label, ret);
	return;
}
EXPORT_SYMBOL(pwm_disable);

struct pwm_device *pwm_request(int pwm_id, const char *label)
{
	struct pwm_device *pwm;

	list_for_each_entry(pwm, &pwm_list, node) {
		if (pwm->pwm_id == pwm_id) {
			pwm->label = label;
			pwm->pwm_id = pwm_id;
			return pwm;
		}
	}

	return ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(pwm_request);

void pwm_free(struct pwm_device *pwm)
{
	pwm_disable(pwm);
}
EXPORT_SYMBOL(pwm_free);

static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
{
	struct pwm_device *pwm;
	/*
	 * Nothing to be done in probe, this is required to get the
	 * device which is required for ab8500 read and write
	 */
	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
	if (pwm == NULL) {
		dev_err(&pdev->dev, "failed to allocate memory\n");
		return -ENOMEM;
	}
	pwm->dev = &pdev->dev;
	pwm->pwm_id = pdev->id;
	list_add_tail(&pwm->node, &pwm_list);
	platform_set_drvdata(pdev, pwm);
	dev_dbg(pwm->dev, "pwm probe successful\n");
	return 0;
}

static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
{
	struct pwm_device *pwm = platform_get_drvdata(pdev);
	list_del(&pwm->node);
	dev_dbg(&pdev->dev, "pwm driver removed\n");
	kfree(pwm);
	return 0;
}

static struct platform_driver ab8500_pwm_driver = {
	.driver = {
		.name = "ab8500-pwm",
		.owner = THIS_MODULE,
	},
	.probe = ab8500_pwm_probe,
	.remove = __devexit_p(ab8500_pwm_remove),
};

static int __init ab8500_pwm_init(void)
{
	return platform_driver_register(&ab8500_pwm_driver);
}

static void __exit ab8500_pwm_exit(void)
{
	platform_driver_unregister(&ab8500_pwm_driver);
}

subsys_initcall(ab8500_pwm_init);
module_exit(ab8500_pwm_exit);
MODULE_AUTHOR("Arun MURTHY <[email protected]>");
MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
MODULE_ALIAS("AB8500 PWM driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
f0f05b1c AM	1	/*
	2	* Copyright (C) ST-Ericsson SA 2010
	3	*
	4	* Author: Arun R Murthy <[email protected]>
	5	* License terms: GNU General Public License (GPL) version 2
	6	*/
	7	#include <linux/err.h>
	8	#include <linux/platform_device.h>
	9	#include <linux/slab.h>
	10	#include <linux/pwm.h>
	11	#include <linux/mfd/ab8500.h>
	12	#include <linux/mfd/abx500.h>
	13
	14	/*
	15	* PWM Out generators
	16	* Bank: 0x10
	17	*/
	18	#define AB8500_PWM_OUT_CTRL1_REG 0x60
	19	#define AB8500_PWM_OUT_CTRL2_REG 0x61
	20	#define AB8500_PWM_OUT_CTRL7_REG 0x66
	21
	22	/* backlight driver constants */
	23	#define ENABLE_PWM 1
	24	#define DISABLE_PWM 0
	25
	26	struct pwm_device {
	27	struct device *dev;
	28	struct list_head node;
	29	const char *label;
	30	unsigned int pwm_id;
	31	};
	32
	33	static LIST_HEAD(pwm_list);
	34
	35	int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
	36	{
	37	int ret = 0;
	38	unsigned int higher_val, lower_val;
	39	u8 reg;
	40
	41	/*
	42	* get the first 8 bits that are be written to
	43	* AB8500_PWM_OUT_CTRL1_REG[0:7]
	44	*/
	45	lower_val = duty_ns & 0x00FF;
	46	/*
	47	* get bits [9:10] that are to be written to
	48	* AB8500_PWM_OUT_CTRL2_REG[0:1]
	49	*/
	50	higher_val = ((duty_ns & 0x0300) >> 8);
	51
	52	reg = AB8500_PWM_OUT_CTRL1_REG + ((pwm->pwm_id - 1) * 2);
	53
	54	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
	55	reg, (u8)lower_val);
	56	if (ret < 0)
	57	return ret;
	58	ret = abx500_set_register_interruptible(pwm->dev, AB8500_MISC,
	59	(reg + 1), (u8)higher_val);
	60
	61	return ret;
	62	}
	63	EXPORT_SYMBOL(pwm_config);
	64
65	int pwm_enable(struct pwm_device *pwm)
66	{
67	int ret;
68
69	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
70	AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
71	1 << (pwm->pwm_id-1), ENABLE_PWM);
72	if (ret < 0)
73	dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
74	pwm->label, ret);
75	return ret;
76	}
77	EXPORT_SYMBOL(pwm_enable);
78
79	void pwm_disable(struct pwm_device *pwm)
80	{
81	int ret;
82
83	ret = abx500_mask_and_set_register_interruptible(pwm->dev,
84	AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
85	1 << (pwm->pwm_id-1), DISABLE_PWM);
86	if (ret < 0)
87	dev_err(pwm->dev, "%s: Failed to disable PWM, Error %d\n",
88	pwm->label, ret);
89	return;
90	}
91	EXPORT_SYMBOL(pwm_disable);
92
93	struct pwm_device pwm_request(int pwm_id, const char label)
94	{
95	struct pwm_device *pwm;
96
97	list_for_each_entry(pwm, &pwm_list, node) {
98	if (pwm->pwm_id == pwm_id) {
99	pwm->label = label;
100	pwm->pwm_id = pwm_id;
101	return pwm;
102	}
103	}
104
105	return ERR_PTR(-ENOENT);
106	}
107	EXPORT_SYMBOL(pwm_request);
108
109	void pwm_free(struct pwm_device *pwm)
110	{
111	pwm_disable(pwm);
112	}
113	EXPORT_SYMBOL(pwm_free);
114
115	static int __devinit ab8500_pwm_probe(struct platform_device *pdev)
116	{
117	struct pwm_device *pwm;
118	/*
119	* Nothing to be done in probe, this is required to get the
120	* device which is required for ab8500 read and write
121	*/
122	pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL);
123	if (pwm == NULL) {
124	dev_err(&pdev->dev, "failed to allocate memory\n");
125	return -ENOMEM;
126	}
127	pwm->dev = &pdev->dev;
128	pwm->pwm_id = pdev->id;
129	list_add_tail(&pwm->node, &pwm_list);
130	platform_set_drvdata(pdev, pwm);
131	dev_dbg(pwm->dev, "pwm probe successful\n");
132	return 0;
133	}
134
135	static int __devexit ab8500_pwm_remove(struct platform_device *pdev)
136	{
137	struct pwm_device *pwm = platform_get_drvdata(pdev);
138	list_del(&pwm->node);
139	dev_dbg(&pdev->dev, "pwm driver removed\n");
140	kfree(pwm);
141	return 0;
142	}
143
144	static struct platform_driver ab8500_pwm_driver = {
145	.driver = {
146	.name = "ab8500-pwm",
147	.owner = THIS_MODULE,
148	},
149	.probe = ab8500_pwm_probe,
150	.remove = __devexit_p(ab8500_pwm_remove),
151	};
152
153	static int __init ab8500_pwm_init(void)
154	{
155	return platform_driver_register(&ab8500_pwm_driver);
156	}
157
158	static void __exit ab8500_pwm_exit(void)
159	{
160	platform_driver_unregister(&ab8500_pwm_driver);
161	}
162
163	subsys_initcall(ab8500_pwm_init);
164	module_exit(ab8500_pwm_exit);
165	MODULE_AUTHOR("Arun MURTHY <[email protected]>");
166	MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
167	MODULE_ALIAS("AB8500 PWM driver");
168	MODULE_LICENSE("GPL v2");