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9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/moduleparam.h>
12#include <linux/device.h>
13#include <linux/types.h>
14#include <linux/delay.h>
15#include <linux/slab.h>
16
17#include <linux/w1.h>
18
19#define W1_FAMILY_DS2413 0x3A
20
21#define W1_F3A_RETRIES 3
22#define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
23#define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
24#define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
25#define W1_F3A_INVALID_PIO_STATE 0xFF
26
27static ssize_t state_read(struct file *filp, struct kobject *kobj,
28 struct bin_attribute *bin_attr, char *buf, loff_t off,
29 size_t count)
30{
31 struct w1_slave *sl = kobj_to_w1_slave(kobj);
32 unsigned int retries = W1_F3A_RETRIES;
33 ssize_t bytes_read = -EIO;
34 u8 state;
35
36 dev_dbg(&sl->dev,
37 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
38 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
39
40 if (off != 0)
41 return 0;
42 if (!buf)
43 return -EINVAL;
44
45 mutex_lock(&sl->master->bus_mutex);
46 dev_dbg(&sl->dev, "mutex locked");
47
48next:
49 if (w1_reset_select_slave(sl))
50 goto out;
51
52 while (retries--) {
53 w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
54
55 state = w1_read_8(sl->master);
56 if ((state & 0x0F) == ((~state >> 4) & 0x0F)) {
57
58 *buf = state;
59 bytes_read = 1;
60 goto out;
61 } else if (state == W1_F3A_INVALID_PIO_STATE) {
62
63 dev_warn(&sl->dev, "slave device did not respond to PIO_ACCESS_READ, " \
64 "reselecting, retries left: %d\n", retries);
65 goto next;
66 }
67
68 if (w1_reset_resume_command(sl->master))
69 goto out;
70
71 dev_warn(&sl->dev, "PIO_ACCESS_READ error, retries left: %d\n", retries);
72 }
73
74out:
75 mutex_unlock(&sl->master->bus_mutex);
76 dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
77 (bytes_read > 0) ? "succeeded" : "error", retries);
78 return bytes_read;
79}
80
81static BIN_ATTR_RO(state, 1);
82
83static ssize_t output_write(struct file *filp, struct kobject *kobj,
84 struct bin_attribute *bin_attr, char *buf,
85 loff_t off, size_t count)
86{
87 struct w1_slave *sl = kobj_to_w1_slave(kobj);
88 u8 w1_buf[3];
89 unsigned int retries = W1_F3A_RETRIES;
90 ssize_t bytes_written = -EIO;
91
92 if (count != 1 || off != 0)
93 return -EFAULT;
94
95 dev_dbg(&sl->dev, "locking mutex for write_output");
96 mutex_lock(&sl->master->bus_mutex);
97 dev_dbg(&sl->dev, "mutex locked");
98
99 if (w1_reset_select_slave(sl))
100 goto out;
101
102
103
104 *buf = *buf | 0xFC;
105
106 while (retries--) {
107 w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
108 w1_buf[1] = *buf;
109 w1_buf[2] = ~(*buf);
110 w1_write_block(sl->master, w1_buf, 3);
111
112 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
113 bytes_written = 1;
114 goto out;
115 }
116 if (w1_reset_resume_command(sl->master))
117 goto out;
118
119 dev_warn(&sl->dev, "PIO_ACCESS_WRITE error, retries left: %d\n", retries);
120 }
121
122out:
123 mutex_unlock(&sl->master->bus_mutex);
124 dev_dbg(&sl->dev, "%s, mutex unlocked, retries: %d\n",
125 (bytes_written > 0) ? "succeeded" : "error", retries);
126 return bytes_written;
127}
128
129static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
130
131static struct bin_attribute *w1_f3a_bin_attrs[] = {
132 &bin_attr_state,
133 &bin_attr_output,
134 NULL,
135};
136
137static const struct attribute_group w1_f3a_group = {
138 .bin_attrs = w1_f3a_bin_attrs,
139};
140
141static const struct attribute_group *w1_f3a_groups[] = {
142 &w1_f3a_group,
143 NULL,
144};
145
146static const struct w1_family_ops w1_f3a_fops = {
147 .groups = w1_f3a_groups,
148};
149
150static struct w1_family w1_family_3a = {
151 .fid = W1_FAMILY_DS2413,
152 .fops = &w1_f3a_fops,
153};
154module_w1_family(w1_family_3a);
155
156MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
157MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
158MODULE_LICENSE("GPL");
159MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));
160