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
|
/*
* w1-gpio - GPIO w1 bus master driver
*
* Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
*
* 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/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/w1-gpio.h>
#include "../w1.h"
#include "../w1_int.h"
#include <asm/gpio.h>
static void w1_gpio_write_bit_dir(void *data, u8 bit)
{
struct w1_gpio_platform_data *pdata = data;
if (bit)
gpio_direction_input(pdata->pin);
else
gpio_direction_output(pdata->pin, 0);
}
static void w1_gpio_write_bit_val(void *data, u8 bit)
{
struct w1_gpio_platform_data *pdata = data;
gpio_set_value(pdata->pin, bit);
}
static u8 w1_gpio_read_bit(void *data)
{
struct w1_gpio_platform_data *pdata = data;
return gpio_get_value(pdata->pin) ? 1 : 0;
}
static int __init w1_gpio_probe(struct platform_device *pdev)
{
struct w1_bus_master *master;
struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
int err;
if (!pdata)
return -ENXIO;
master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL);
if (!master)
return -ENOMEM;
err = gpio_request(pdata->pin, "w1");
if (err)
goto free_master;
master->data = pdata;
master->read_bit = w1_gpio_read_bit;
if (pdata->is_open_drain) {
gpio_direction_output(pdata->pin, 1);
master->write_bit = w1_gpio_write_bit_val;
} else {
gpio_direction_input(pdata->pin);
master->write_bit = w1_gpio_write_bit_dir;
}
err = w1_add_master_device(master);
if (err)
goto free_gpio;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
platform_set_drvdata(pdev, master);
return 0;
free_gpio:
gpio_free(pdata->pin);
free_master:
kfree(master);
return err;
}
static int __exit w1_gpio_remove(struct platform_device *pdev)
{
struct w1_bus_master *master = platform_get_drvdata(pdev);
struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
w1_remove_master_device(master);
gpio_free(pdata->pin);
kfree(master);
return 0;
}
#ifdef CONFIG_PM
static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state)
{
struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(0);
return 0;
}
static int w1_gpio_resume(struct platform_device *pdev)
{
struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
return 0;
}
#else
#define w1_gpio_suspend NULL
#define w1_gpio_resume NULL
#endif
static struct platform_driver w1_gpio_driver = {
.driver = {
.name = "w1-gpio",
.owner = THIS_MODULE,
},
.remove = __exit_p(w1_gpio_remove),
.suspend = w1_gpio_suspend,
.resume = w1_gpio_resume,
};
static int __init w1_gpio_init(void)
{
return platform_driver_probe(&w1_gpio_driver, w1_gpio_probe);
}
static void __exit w1_gpio_exit(void)
{
platform_driver_unregister(&w1_gpio_driver);
}
module_init(w1_gpio_init);
module_exit(w1_gpio_exit);
MODULE_DESCRIPTION("GPIO w1 bus master driver");
MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
MODULE_LICENSE("GPL");
|
