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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* w1_ds2413.c - w1 family 3a (DS2413) driver
* based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
*
* Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
*/
#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/w1.h>
#define W1_FAMILY_DS2413 0x3A
#define W1_F3A_RETRIES 3
#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
#define W1_F3A_INVALID_PIO_STATE 0xFF
static ssize_t state_read(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);
unsigned int retries = W1_F3A_RETRIES;
ssize_t bytes_read = -EIO;
u8 state;
dev_dbg(&sl->dev,
"Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
if (off != 0)
return 0;
if (!buf)
return -EINVAL;
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
next:
if (w1_reset_select_slave(sl))
goto out;
while (retries--) {
w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
state = w1_read_8(sl->master);
if ((state & 0x0F) == ((~state >> 4) & 0x0F)) {
/* complement is correct */
*buf = state;
bytes_read = 1;
goto out;
} else if (state == W1_F3A_INVALID_PIO_STATE) {
/* slave didn't respond, try to select it again */
dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \
"reselecting, retries left: %d\n", retries);
goto next;
}
if (w1_reset_resume_command(sl->master))
goto out; /* unrecoverable error */
dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries);
}
out:
mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
(bytes_read > 0) ? "succeeded" : "error", retries);
return bytes_read;
}
static BIN_ATTR_RO(state, 1);
static ssize_t output_write(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[3];
unsigned int retries = W1_F3A_RETRIES;
ssize_t bytes_written = -EIO;
if (count != 1 || off != 0)
return -EFAULT;
dev_dbg(&sl->dev, "locking mutex for write_output");
mutex_lock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "mutex locked");
if (w1_reset_select_slave(sl))
goto out;
/*
* according to the DS2413 datasheet the most significant 6 bits
* should be set to "1"s, so do it now
*/
*buf = *buf | 0xFC;
while (retries--) {
w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
w1_buf[1] = *buf;
w1_buf[2] = ~(*buf);
w1_write_block(sl->master, w1_buf, 3);
if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
bytes_written = 1;
goto out;
}
if (w1_reset_resume_command(sl->master))
goto out; /* unrecoverable error */
dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
}
out:
mutex_unlock(&sl->master->bus_mutex);
dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
(bytes_written > 0) ? "succeeded" : "error", retries);
return bytes_written;
}
static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
static struct bin_attribute *w1_f3a_bin_attrs[] = {
&bin_attr_state,
&bin_attr_output,
NULL,
};
static const struct attribute_group w1_f3a_group = {
.bin_attrs = w1_f3a_bin_attrs,
};
static const struct attribute_group *w1_f3a_groups[] = {
&w1_f3a_group,
NULL,
};
static const struct w1_family_ops w1_f3a_fops = {
.groups = w1_f3a_groups,
};
static struct w1_family w1_family_3a = {
.fid = W1_FAMILY_DS2413,
.fops = &w1_f3a_fops,
};
module_w1_family(w1_family_3a);
MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));
|
