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>
20 #include "../w1_int.h"
21 #include "../w1_family.h"
23 MODULE_LICENSE("GPL");
24 MODULE_AUTHOR("Mariusz Bialonczyk <manio@skyboo.net>");
25 MODULE_DESCRIPTION("w1 family 3a driver for DS2413 2 Pin IO");
26 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2413));
28 #define W1_F3A_RETRIES 3
29 #define W1_F3A_FUNC_PIO_ACCESS_READ 0xF5
30 #define W1_F3A_FUNC_PIO_ACCESS_WRITE 0x5A
31 #define W1_F3A_SUCCESS_CONFIRM_BYTE 0xAA
33 static ssize_t w1_f3a_read_state(
34 struct file *filp, struct kobject *kobj,
35 struct bin_attribute *bin_attr,
36 char *buf, loff_t off, size_t count)
38 struct w1_slave *sl = kobj_to_w1_slave(kobj);
40 "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p",
41 bin_attr->attr.name, kobj, (unsigned int)off, count, buf);
48 mutex_lock(&sl->master->bus_mutex);
49 dev_dbg(&sl->dev, "mutex locked");
51 if (w1_reset_select_slave(sl)) {
52 mutex_unlock(&sl->master->bus_mutex);
56 w1_write_8(sl->master, W1_F3A_FUNC_PIO_ACCESS_READ);
57 *buf = w1_read_8(sl->master);
59 mutex_unlock(&sl->master->bus_mutex);
60 dev_dbg(&sl->dev, "mutex unlocked");
62 /* check for correct complement */
63 if ((*buf & 0x0F) != ((~*buf >> 4) & 0x0F))
69 static ssize_t w1_f3a_write_output(
70 struct file *filp, struct kobject *kobj,
71 struct bin_attribute *bin_attr,
72 char *buf, loff_t off, size_t count)
74 struct w1_slave *sl = kobj_to_w1_slave(kobj);
76 unsigned int retries = W1_F3A_RETRIES;
78 if (count != 1 || off != 0)
81 dev_dbg(&sl->dev, "locking mutex for write_output");
82 mutex_lock(&sl->master->bus_mutex);
83 dev_dbg(&sl->dev, "mutex locked");
85 if (w1_reset_select_slave(sl))
88 /* according to the DS2413 datasheet the most significant 6 bits
89 should be set to "1"s, so do it now */
93 w1_buf[0] = W1_F3A_FUNC_PIO_ACCESS_WRITE;
96 w1_write_block(sl->master, w1_buf, 3);
98 if (w1_read_8(sl->master) == W1_F3A_SUCCESS_CONFIRM_BYTE) {
99 mutex_unlock(&sl->master->bus_mutex);
100 dev_dbg(&sl->dev, "mutex unlocked, retries:%d", retries);
103 if (w1_reset_resume_command(sl->master))
108 mutex_unlock(&sl->master->bus_mutex);
109 dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
113 #define NB_SYSFS_BIN_FILES 2
114 static struct bin_attribute w1_f3a_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
121 .read = w1_f3a_read_state,
126 .mode = S_IRUGO | S_IWUSR | S_IWGRP,
129 .write = w1_f3a_write_output,
133 static int w1_f3a_add_slave(struct w1_slave *sl)
138 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
139 err = sysfs_create_bin_file(
141 &(w1_f3a_sysfs_bin_files[i]));
144 sysfs_remove_bin_file(&sl->dev.kobj,
145 &(w1_f3a_sysfs_bin_files[i]));
149 static void w1_f3a_remove_slave(struct w1_slave *sl)
152 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
153 sysfs_remove_bin_file(&sl->dev.kobj,
154 &(w1_f3a_sysfs_bin_files[i]));
157 static struct w1_family_ops w1_f3a_fops = {
158 .add_slave = w1_f3a_add_slave,
159 .remove_slave = w1_f3a_remove_slave,
162 static struct w1_family w1_family_3a = {
163 .fid = W1_FAMILY_DS2413,
164 .fops = &w1_f3a_fops,
167 static int __init w1_f3a_init(void)
169 return w1_register_family(&w1_family_3a);
172 static void __exit w1_f3a_exit(void)
174 w1_unregister_family(&w1_family_3a);
177 module_init(w1_f3a_init);
178 module_exit(w1_f3a_exit);