1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* Copyright (C) ST-Ericsson SA 2010
*
* Author: Arun R Murthy <arun.murthy@stericsson.com>
* 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/abx500.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/module.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 ab8500_pwm_chip {
struct pwm_chip chip;
};
static int ab8500_pwm_config(struct pwm_chip *chip, 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 + ((chip->base - 1) * 2);
ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
reg, (u8)lower_val);
if (ret < 0)
return ret;
ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
(reg + 1), (u8)higher_val);
return ret;
}
static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
ret = abx500_mask_and_set_register_interruptible(chip->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (chip->base - 1), ENABLE_PWM);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
pwm->label, ret);
return ret;
}
static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
{
int ret;
ret = abx500_mask_and_set_register_interruptible(chip->dev,
AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
1 << (chip->base - 1), DISABLE_PWM);
if (ret < 0)
dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
pwm->label, ret);
return;
}
static const struct pwm_ops ab8500_pwm_ops = {
.config = ab8500_pwm_config,
.enable = ab8500_pwm_enable,
.disable = ab8500_pwm_disable,
};
static int ab8500_pwm_probe(struct platform_device *pdev)
{
struct ab8500_pwm_chip *ab8500;
int err;
/*
* Nothing to be done in probe, this is required to get the
* device which is required for ab8500 read and write
*/
ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
if (ab8500 == NULL) {
dev_err(&pdev->dev, "failed to allocate memory\n");
return -ENOMEM;
}
ab8500->chip.dev = &pdev->dev;
ab8500->chip.ops = &ab8500_pwm_ops;
ab8500->chip.base = pdev->id;
ab8500->chip.npwm = 1;
err = pwmchip_add(&ab8500->chip);
if (err < 0)
return err;
dev_dbg(&pdev->dev, "pwm probe successful\n");
platform_set_drvdata(pdev, ab8500);
return 0;
}
static int ab8500_pwm_remove(struct platform_device *pdev)
{
struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
int err;
err = pwmchip_remove(&ab8500->chip);
if (err < 0)
return err;
dev_dbg(&pdev->dev, "pwm driver removed\n");
return 0;
}
static struct platform_driver ab8500_pwm_driver = {
.driver = {
.name = "ab8500-pwm",
.owner = THIS_MODULE,
},
.probe = ab8500_pwm_probe,
.remove = ab8500_pwm_remove,
};
module_platform_driver(ab8500_pwm_driver);
MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
MODULE_ALIAS("platform:ab8500-pwm");
MODULE_LICENSE("GPL v2");
|
