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
|
/*
* w1_ds2406.c - w1 family 12 (DS2406) driver
* based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
*
* Copyright (c) 2014 Scott Alfter <scott@alfter.us>
*
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/crc16.h>
#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
#define W1_F12_FUNC_READ_STATUS 0xAA
#define W1_F12_FUNC_WRITE_STATUS 0x55
static ssize_t w1_f12_read_state(
struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u16 crc=0;
int i;
ssize_t rtnval=1;
if (off != 0)
return 0;
if (!buf)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
if (w1_reset_select_slave(sl)) {
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
w1_write_block(sl->master, w1_buf, 3);
w1_read_block(sl->master, w1_buf+3, 3);
for (i=0; i<6; i++)
crc=crc16_byte(crc, w1_buf[i]);
if (crc==0xb001) /* good read? */
*buf=((w1_buf[3]>>5)&3)|0x30;
else
rtnval=-EIO;
mutex_unlock(&sl->master->bus_mutex);
return rtnval;
}
static ssize_t w1_f12_write_output(
struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
u16 crc=0;
int i;
ssize_t rtnval=1;
if (count != 1 || off != 0)
return -EFAULT;
mutex_lock(&sl->master->bus_mutex);
if (w1_reset_select_slave(sl)) {
mutex_unlock(&sl->master->bus_mutex);
return -EIO;
}
w1_buf[3] = (((*buf)&3)<<5)|0x1F;
w1_write_block(sl->master, w1_buf, 4);
w1_read_block(sl->master, w1_buf+4, 2);
for (i=0; i<6; i++)
crc=crc16_byte(crc, w1_buf[i]);
if (crc==0xb001) /* good read? */
w1_write_8(sl->master, 0xFF);
else
rtnval=-EIO;
mutex_unlock(&sl->master->bus_mutex);
return rtnval;
}
#define NB_SYSFS_BIN_FILES 2
static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
{
.attr = {
.name = "state",
.mode = S_IRUGO,
},
.size = 1,
.read = w1_f12_read_state,
},
{
.attr = {
.name = "output",
.mode = S_IRUGO | S_IWUSR | S_IWGRP,
},
.size = 1,
.write = w1_f12_write_output,
}
};
static int w1_f12_add_slave(struct w1_slave *sl)
{
int err = 0;
int i;
for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
err = sysfs_create_bin_file(
&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
if (err)
while (--i >= 0)
sysfs_remove_bin_file(&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
return err;
}
static void w1_f12_remove_slave(struct w1_slave *sl)
{
int i;
for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
sysfs_remove_bin_file(&sl->dev.kobj,
&(w1_f12_sysfs_bin_files[i]));
}
static struct w1_family_ops w1_f12_fops = {
.add_slave = w1_f12_add_slave,
.remove_slave = w1_f12_remove_slave,
};
static struct w1_family w1_family_12 = {
.fid = W1_FAMILY_DS2406,
.fops = &w1_f12_fops,
};
static int __init w1_f12_init(void)
{
return w1_register_family(&w1_family_12);
}
static void __exit w1_f12_exit(void)
{
w1_unregister_family(&w1_family_12);
}
module_init(w1_f12_init);
module_exit(w1_f12_exit);
|
