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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* 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/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 <arun.murthy@stericsson.com>");
MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
MODULE_ALIAS("platform:ab8500-pwm");
MODULE_LICENSE("GPL v2");
|
