2 * w1_ds2413.c - w1 family 3a (DS2413) driver
3 * based on w1_ds2408.c by Jean-Francois Dagenais <dagenaisj@sonatest.com>
5 * Copyright (c) 2013 Mariusz Bialonczyk <manio@skyboo.net>
7 * This source code is licensed under the GNU General Public License,
8 * Version 2. See the file COPYING for more details.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/device.h>
15 #include <linux/types.h>
16 #include <linux/delay.h>
17 #include <linux/slab.h>
21 #define W1_FAMILY_DS2413 0x3A
23 #define W1_F3A_RETRIES 3
24 #define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
25 #define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
26 #define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
28 static ssize_t state_read(struct file *filp, struct kobject *kobj,
29 struct bin_attribute *bin_attr, char *buf, loff_t off,
32 struct w1_slave *sl = kobj_to_w1_slave(kobj);
34 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
35 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
42 mutex_lock(&sl->master->bus_mutex);
43 dev_dbg(&sl->dev, "mutex locked");
45 if (w1_reset_select_slave(sl)) {
46 mutex_unlock(&sl->master->bus_mutex);
50 w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
51 *buf = w1_read_8(sl->master);
53 mutex_unlock(&sl->master->bus_mutex);
54 dev_dbg(&sl->dev, "mutex unlocked");
56 /* check for correct complement */
57 if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
63 static BIN_ATTR_RO(state, 1);
65 static ssize_t output_write(struct file *filp, struct kobject *kobj,
66 struct bin_attribute *bin_attr, char *buf,
67 loff_t off, size_t count)
69 struct w1_slave *sl = kobj_to_w1_slave(kobj);
71 unsigned int retries = W1_F3A_RETRIES;
73 if (count != 1 || off != 0)
76 dev_dbg(&sl->dev, "locking mutex for write_output");
77 mutex_lock(&sl->master->bus_mutex);
78 dev_dbg(&sl->dev, "mutex locked");
80 if (w1_reset_select_slave(sl))
83 /* according to the DS2413 datasheet the most significant 6 bits
84 should be set to "1"s, so do it now */
88 w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
91 w1_write_block(sl->master, w1_buf, 3);
93 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
94 mutex_unlock(&sl->master->bus_mutex);
95 dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
98 if (w1_reset_resume_command(sl->master))
103 mutex_unlock(&sl->master->bus_mutex);
104 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
108 static BIN_ATTR(output, S_IRUGO | S_IWUSR | S_IWGRP, NULL, output_write, 1);
110 static struct bin_attribute *w1_f3a_bin_attrs[] = {
116 static const struct attribute_group w1_f3a_group = {
117 .bin_attrs = w1_f3a_bin_attrs,
120 static const struct attribute_group *w1_f3a_groups[] = {
125 static struct w1_family_ops w1_f3a_fops = {
126 .groups = w1_f3a_groups,
129 static struct w1_family w1_family_3a = {
130 .fid = W1_FAMILY_DS2413,
131 .fops = &w1_f3a_fops,
133 module_w1_family(w1_family_3a);
135 MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
136 MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
137 MODULE_LICENSE("GPL");
138 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));