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
|
/*
* linux/drivers/leds-pwm.c
*
* simple PWM based LED control
*
* Copyright 2009 Luotao Fu @ Pengutronix (l.fu@pengutronix.de)
*
* based on leds-gpio.c by Raphael Assenat <raph@8d.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/fb.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/pwm.h>
#include <linux/leds_pwm.h>
#include <linux/slab.h>
struct led_pwm_data {
struct led_classdev cdev;
struct pwm_device *pwm;
unsigned int active_low;
unsigned int period;
};
static void led_pwm_set(struct led_classdev *led_cdev,
enum led_brightness brightness)
{
struct led_pwm_data *led_dat =
container_of(led_cdev, struct led_pwm_data, cdev);
unsigned int max = led_dat->cdev.max_brightness;
unsigned int period = led_dat->period;
if (brightness == 0) {
pwm_config(led_dat->pwm, 0, period);
pwm_disable(led_dat->pwm);
} else {
pwm_config(led_dat->pwm, brightness * period / max, period);
pwm_enable(led_dat->pwm);
}
}
static int led_pwm_probe(struct platform_device *pdev)
{
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
struct led_pwm *cur_led;
struct led_pwm_data *leds_data, *led_dat;
int i, ret = 0;
if (!pdata)
return -EBUSY;
leds_data = kzalloc(sizeof(struct led_pwm_data) * pdata->num_leds,
GFP_KERNEL);
if (!leds_data)
return -ENOMEM;
for (i = 0; i < pdata->num_leds; i++) {
cur_led = &pdata->leds[i];
led_dat = &leds_data[i];
led_dat->pwm = pwm_request(cur_led->pwm_id,
cur_led->name);
if (IS_ERR(led_dat->pwm)) {
dev_err(&pdev->dev, "unable to request PWM %d\n",
cur_led->pwm_id);
goto err;
}
led_dat->cdev.name = cur_led->name;
led_dat->cdev.default_trigger = cur_led->default_trigger;
led_dat->active_low = cur_led->active_low;
led_dat->period = cur_led->pwm_period_ns;
led_dat->cdev.brightness_set = led_pwm_set;
led_dat->cdev.brightness = LED_OFF;
led_dat->cdev.max_brightness = cur_led->max_brightness;
led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
if (ret < 0) {
pwm_free(led_dat->pwm);
goto err;
}
}
platform_set_drvdata(pdev, leds_data);
return 0;
err:
if (i > 0) {
for (i = i - 1; i >= 0; i--) {
led_classdev_unregister(&leds_data[i].cdev);
pwm_free(leds_data[i].pwm);
}
}
kfree(leds_data);
return ret;
}
static int __devexit led_pwm_remove(struct platform_device *pdev)
{
int i;
struct led_pwm_platform_data *pdata = pdev->dev.platform_data;
struct led_pwm_data *leds_data;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++) {
led_classdev_unregister(&leds_data[i].cdev);
pwm_free(leds_data[i].pwm);
}
kfree(leds_data);
return 0;
}
static struct platform_driver led_pwm_driver = {
.probe = led_pwm_probe,
.remove = __devexit_p(led_pwm_remove),
.driver = {
.name = "leds_pwm",
.owner = THIS_MODULE,
},
};
static int __init led_pwm_init(void)
{
return platform_driver_register(&led_pwm_driver);
}
static void __exit led_pwm_exit(void)
{
platform_driver_unregister(&led_pwm_driver);
}
module_init(led_pwm_init);
module_exit(led_pwm_exit);
MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>");
MODULE_DESCRIPTION("PWM LED driver for PXA");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:leds-pwm");
|
