1/*
2 * Copyright (C) ST-Ericsson SA 2010
3 *
4 * Author: Arun R Murthy <arun.murthy@stericsson.com>
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/abx500.h>
12#include <linux/mfd/abx500/ab8500.h>
13#include <linux/module.h>
14
15/*
16 * PWM Out generators
17 * Bank: 0x10
18 */
19#define AB8500_PWM_OUT_CTRL1_REG	0x60
20#define AB8500_PWM_OUT_CTRL2_REG	0x61
21#define AB8500_PWM_OUT_CTRL7_REG	0x66
22
23struct ab8500_pwm_chip {
24	struct pwm_chip chip;
25};
26
27static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
28			     int duty_ns, int period_ns)
29{
30	int ret = 0;
31	unsigned int higher_val, lower_val;
32	u8 reg;
33
34	/*
35	 * get the first 8 bits that are be written to
36	 * AB8500_PWM_OUT_CTRL1_REG[0:7]
37	 */
38	lower_val = duty_ns & 0x00FF;
39	/*
40	 * get bits [9:10] that are to be written to
41	 * AB8500_PWM_OUT_CTRL2_REG[0:1]
42	 */
43	higher_val = ((duty_ns & 0x0300) >> 8);
44
45	reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2);
46
47	ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
48			reg, (u8)lower_val);
49	if (ret < 0)
50		return ret;
51	ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
52			(reg + 1), (u8)higher_val);
53
54	return ret;
55}
56
57static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
58{
59	int ret;
60
61	ret = abx500_mask_and_set_register_interruptible(chip->dev,
62				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
63				1 << (chip->base - 1), 1 << (chip->base - 1));
64	if (ret < 0)
65		dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
66							pwm->label, ret);
67	return ret;
68}
69
70static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
71{
72	int ret;
73
74	ret = abx500_mask_and_set_register_interruptible(chip->dev,
75				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
76				1 << (chip->base - 1), 0);
77	if (ret < 0)
78		dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
79							pwm->label, ret);
80}
81
82static const struct pwm_ops ab8500_pwm_ops = {
83	.config = ab8500_pwm_config,
84	.enable = ab8500_pwm_enable,
85	.disable = ab8500_pwm_disable,
86	.owner = THIS_MODULE,
87};
88
89static int ab8500_pwm_probe(struct platform_device *pdev)
90{
91	struct ab8500_pwm_chip *ab8500;
92	int err;
93
94	/*
95	 * Nothing to be done in probe, this is required to get the
96	 * device which is required for ab8500 read and write
97	 */
98	ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
99	if (ab8500 == NULL)
100		return -ENOMEM;
101
102	ab8500->chip.dev = &pdev->dev;
103	ab8500->chip.ops = &ab8500_pwm_ops;
104	ab8500->chip.base = pdev->id;
105	ab8500->chip.npwm = 1;
106
107	err = pwmchip_add(&ab8500->chip);
108	if (err < 0)
109		return err;
110
111	dev_dbg(&pdev->dev, "pwm probe successful\n");
112	platform_set_drvdata(pdev, ab8500);
113
114	return 0;
115}
116
117static int ab8500_pwm_remove(struct platform_device *pdev)
118{
119	struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
120	int err;
121
122	err = pwmchip_remove(&ab8500->chip);
123	if (err < 0)
124		return err;
125
126	dev_dbg(&pdev->dev, "pwm driver removed\n");
127
128	return 0;
129}
130
131static struct platform_driver ab8500_pwm_driver = {
132	.driver = {
133		.name = "ab8500-pwm",
134	},
135	.probe = ab8500_pwm_probe,
136	.remove = ab8500_pwm_remove,
137};
138module_platform_driver(ab8500_pwm_driver);
139
140MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
141MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
142MODULE_ALIAS("platform:ab8500-pwm");
143MODULE_LICENSE("GPL v2");
144