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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/*
* LEDs driver for GPIOs
*
* Copyright (C) 2007 8D Technologies inc.
* 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/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/workqueue.h>
#include <asm/gpio.h>
struct gpio_led_data {
struct led_classdev cdev;
unsigned gpio;
struct work_struct work;
u8 new_level;
u8 can_sleep;
u8 active_low;
};
static void gpio_led_work(struct work_struct *work)
{
struct gpio_led_data *led_dat =
container_of(work, struct gpio_led_data, work);
gpio_set_value_cansleep(led_dat->gpio, led_dat->new_level);
}
static void gpio_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct gpio_led_data *led_dat =
container_of(led_cdev, struct gpio_led_data, cdev);
int level;
if (value == LED_OFF)
level = 0;
else
level = 1;
if (led_dat->active_low)
level = !level;
/* setting GPIOs with I2C/etc requires a preemptible task context */
if (led_dat->can_sleep) {
if (preempt_count()) {
led_dat->new_level = level;
schedule_work(&led_dat->work);
} else
gpio_set_value_cansleep(led_dat->gpio, level);
} else
gpio_set_value(led_dat->gpio, level);
}
static int gpio_led_probe(struct platform_device *pdev)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led *cur_led;
struct gpio_led_data *leds_data, *led_dat;
int i, ret = 0;
if (!pdata)
return -EBUSY;
leds_data = kzalloc(sizeof(struct gpio_led_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];
ret = gpio_request(cur_led->gpio, cur_led->name);
if (ret < 0)
goto err;
led_dat->cdev.name = cur_led->name;
led_dat->cdev.default_trigger = cur_led->default_trigger;
led_dat->gpio = cur_led->gpio;
led_dat->can_sleep = gpio_cansleep(cur_led->gpio);
led_dat->active_low = cur_led->active_low;
led_dat->cdev.brightness_set = gpio_led_set;
led_dat->cdev.brightness = LED_OFF;
gpio_direction_output(led_dat->gpio, led_dat->active_low);
INIT_WORK(&led_dat->work, gpio_led_work);
ret = led_classdev_register(&pdev->dev, &led_dat->cdev);
if (ret < 0) {
gpio_free(led_dat->gpio);
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);
cancel_work_sync(&leds_data[i].work);
gpio_free(leds_data[i].gpio);
}
}
kfree(leds_data);
return ret;
}
static int __devexit gpio_led_remove(struct platform_device *pdev)
{
int i;
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++) {
led_classdev_unregister(&leds_data[i].cdev);
cancel_work_sync(&leds_data[i].work);
gpio_free(leds_data[i].gpio);
}
kfree(leds_data);
return 0;
}
#ifdef CONFIG_PM
static int gpio_led_suspend(struct platform_device *pdev, pm_message_t state)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
int i;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++)
led_classdev_suspend(&leds_data[i].cdev);
return 0;
}
static int gpio_led_resume(struct platform_device *pdev)
{
struct gpio_led_platform_data *pdata = pdev->dev.platform_data;
struct gpio_led_data *leds_data;
int i;
leds_data = platform_get_drvdata(pdev);
for (i = 0; i < pdata->num_leds; i++)
led_classdev_resume(&leds_data[i].cdev);
return 0;
}
#else
#define gpio_led_suspend NULL
#define gpio_led_resume NULL
#endif
static struct platform_driver gpio_led_driver = {
.probe = gpio_led_probe,
.remove = __devexit_p(gpio_led_remove),
.suspend = gpio_led_suspend,
.resume = gpio_led_resume,
.driver = {
.name = "leds-gpio",
.owner = THIS_MODULE,
},
};
static int __init gpio_led_init(void)
{
return platform_driver_register(&gpio_led_driver);
}
static void __exit gpio_led_exit(void)
{
platform_driver_unregister(&gpio_led_driver);
}
module_init(gpio_led_init);
module_exit(gpio_led_exit);
MODULE_AUTHOR("Raphael Assenat <raph@8d.com>");
MODULE_DESCRIPTION("GPIO LED driver");
MODULE_LICENSE("GPL");
|
