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
|
/*
* drivers/extcon/extcon_gpio.c
*
* Single-state GPIO extcon driver based on extcon class
*
* Copyright (C) 2008 Google, Inc.
* Author: Mike Lockwood <lockwood@android.com>
*
* Modified by MyungJoo Ham <myungjoo.ham@samsung.com> to support extcon
* (originally switch class is supported)
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/extcon.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/extcon.h>
#include <linux/extcon/extcon_gpio.h>
struct gpio_extcon_data {
struct extcon_dev edev;
unsigned gpio;
const char *state_on;
const char *state_off;
int irq;
struct delayed_work work;
unsigned long debounce_jiffies;
};
static void gpio_extcon_work(struct work_struct *work)
{
int state;
struct gpio_extcon_data *data =
container_of(to_delayed_work(work), struct gpio_extcon_data,
work);
state = gpio_get_value(data->gpio);
extcon_set_state(&data->edev, state);
}
static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
{
struct gpio_extcon_data *extcon_data = dev_id;
schedule_delayed_work(&extcon_data->work,
extcon_data->debounce_jiffies);
return IRQ_HANDLED;
}
static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)
{
struct gpio_extcon_data *extcon_data =
container_of(edev, struct gpio_extcon_data, edev);
const char *state;
if (extcon_get_state(edev))
state = extcon_data->state_on;
else
state = extcon_data->state_off;
if (state)
return sprintf(buf, "%s\n", state);
return -EINVAL;
}
static int __devinit gpio_extcon_probe(struct platform_device *pdev)
{
struct gpio_extcon_platform_data *pdata = pdev->dev.platform_data;
struct gpio_extcon_data *extcon_data;
int ret = 0;
if (!pdata)
return -EBUSY;
if (!pdata->irq_flags) {
dev_err(&pdev->dev, "IRQ flag is not specified.\n");
return -EINVAL;
}
extcon_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_extcon_data),
GFP_KERNEL);
if (!extcon_data)
return -ENOMEM;
extcon_data->edev.name = pdata->name;
extcon_data->gpio = pdata->gpio;
extcon_data->state_on = pdata->state_on;
extcon_data->state_off = pdata->state_off;
if (pdata->state_on && pdata->state_off)
extcon_data->edev.print_state = extcon_gpio_print_state;
extcon_data->debounce_jiffies = msecs_to_jiffies(pdata->debounce);
ret = extcon_dev_register(&extcon_data->edev, &pdev->dev);
if (ret < 0)
goto err_extcon_dev_register;
ret = gpio_request_one(extcon_data->gpio, GPIOF_DIR_IN, pdev->name);
if (ret < 0)
goto err_request_gpio;
INIT_DELAYED_WORK(&extcon_data->work, gpio_extcon_work);
extcon_data->irq = gpio_to_irq(extcon_data->gpio);
if (extcon_data->irq < 0) {
ret = extcon_data->irq;
goto err_detect_irq_num_failed;
}
ret = request_any_context_irq(extcon_data->irq, gpio_irq_handler,
pdata->irq_flags, pdev->name,
extcon_data);
if (ret < 0)
goto err_request_irq;
/* Perform initial detection */
gpio_extcon_work(&extcon_data->work.work);
return 0;
err_request_irq:
err_detect_irq_num_failed:
gpio_free(extcon_data->gpio);
err_request_gpio:
extcon_dev_unregister(&extcon_data->edev);
err_extcon_dev_register:
devm_kfree(&pdev->dev, extcon_data);
return ret;
}
static int __devexit gpio_extcon_remove(struct platform_device *pdev)
{
struct gpio_extcon_data *extcon_data = platform_get_drvdata(pdev);
cancel_delayed_work_sync(&extcon_data->work);
gpio_free(extcon_data->gpio);
extcon_dev_unregister(&extcon_data->edev);
devm_kfree(&pdev->dev, extcon_data);
return 0;
}
static struct platform_driver gpio_extcon_driver = {
.probe = gpio_extcon_probe,
.remove = __devexit_p(gpio_extcon_remove),
.driver = {
.name = "extcon-gpio",
.owner = THIS_MODULE,
},
};
module_platform_driver(gpio_extcon_driver);
MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
MODULE_DESCRIPTION("GPIO extcon driver");
MODULE_LICENSE("GPL");
|
