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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/*
* 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/slab.h>
#include <linux/w1-gpio.h>
#include <linux/gpio.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/err.h>
#include <linux/of.h>
#include "../w1.h"
#include "../w1_int.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 struct of_device_id w1_gpio_dt_ids[] = {
{ .compatible = "w1-gpio" },
{}
};
MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids);
static int w1_gpio_probe_dt(struct platform_device *pdev)
{
struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
struct device_node *np = pdev->dev.of_node;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
if (of_get_property(np, "linux,open-drain", NULL))
pdata->is_open_drain = 1;
pdata->pin = of_get_gpio(np, 0);
pdata->ext_pullup_enable_pin = of_get_gpio(np, 1);
pdev->dev.platform_data = pdata;
return 0;
}
static int w1_gpio_probe(struct platform_device *pdev)
{
struct w1_bus_master *master;
struct w1_gpio_platform_data *pdata;
struct pinctrl *pinctrl;
int err;
pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
if (IS_ERR(pinctrl))
dev_warn(&pdev->dev, "unable to select pin group\n");
if (of_have_populated_dt()) {
err = w1_gpio_probe_dt(pdev);
if (err < 0) {
dev_err(&pdev->dev, "Failed to parse DT\n");
return err;
}
}
pdata = pdev->dev.platform_data;
if (!pdata) {
dev_err(&pdev->dev, "No configuration data\n");
return -ENXIO;
}
master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL);
if (!master) {
dev_err(&pdev->dev, "Out of memory\n");
return -ENOMEM;
}
err = gpio_request(pdata->pin, "w1");
if (err) {
dev_err(&pdev->dev, "gpio_request (pin) failed\n");
goto free_master;
}
if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
err = gpio_request_one(pdata->ext_pullup_enable_pin,
GPIOF_INIT_LOW, "w1 pullup");
if (err < 0) {
dev_err(&pdev->dev, "gpio_request_one "
"(ext_pullup_enable_pin) failed\n");
goto free_gpio;
}
}
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) {
dev_err(&pdev->dev, "w1_add_master device failed\n");
goto free_gpio_ext_pu;
}
if (pdata->enable_external_pullup)
pdata->enable_external_pullup(1);
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_set_value(pdata->ext_pullup_enable_pin, 1);
platform_set_drvdata(pdev, master);
return 0;
free_gpio_ext_pu:
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_free(pdata->ext_pullup_enable_pin);
free_gpio:
gpio_free(pdata->pin);
free_master:
kfree(master);
return err;
}
static int 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);
if (gpio_is_valid(pdata->ext_pullup_enable_pin))
gpio_set_value(pdata->ext_pullup_enable_pin, 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,
.of_match_table = of_match_ptr(w1_gpio_dt_ids),
},
.probe = w1_gpio_probe,
.remove = w1_gpio_remove,
.suspend = w1_gpio_suspend,
.resume = w1_gpio_resume,
};
module_platform_driver(w1_gpio_driver);
MODULE_DESCRIPTION("GPIO w1 bus master driver");
MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
MODULE_LICENSE("GPL");
|
