blob: d488961a8c903c3600a65460fc7a5bd9a7f1f4b6 [file] [log] [blame]
Scott Alfter948593082014-06-17 20:42:05 +00001/*
2 * w1_ds2406.c - w1 family 12 (DS2406) driver
3 * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
4 *
5 * Copyright (c) 2014 Scott Alfter <scott@alfter.us>
6 *
7 * This source code is licensed under the GNU General Public License,
8 * Version 2. See the file COPYING for more details.
9 */
10
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>
18#include <linux/crc16.h>
19
20#include "../w1.h"
21#include "../w1_int.h"
22#include "../w1_family.h"
23
24MODULE_LICENSE("GPL");
25MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
26MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
27
28#define W1_F12_FUNC_READ_STATUS 0xAA
29#define W1_F12_FUNC_WRITE_STATUS 0x55
30
31static ssize_t w1_f12_read_state(
32 struct file *filp, struct kobject *kobj,
33 struct bin_attribute *bin_attr,
34 char *buf, loff_t off, size_t count)
35{
36 u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
37 struct w1_slave *sl = kobj_to_w1_slave(kobj);
38 u16 crc=0;
39 int i;
40 ssize_t rtnval=1;
41
42 if (off != 0)
43 return 0;
44 if (!buf)
45 return -EINVAL;
46
47 mutex_lock(&sl->master->bus_mutex);
48
49 if (w1_reset_select_slave(sl)) {
50 mutex_unlock(&sl->master->bus_mutex);
51 return -EIO;
52 }
53
54 w1_write_block(sl->master, w1_buf, 3);
55 w1_read_block(sl->master, w1_buf+3, 3);
56 for (i=0; i<6; i++)
57 crc=crc16_byte(crc, w1_buf[i]);
58 if (crc==0xb001) /* good read? */
59 *buf=((w1_buf[3]>>5)&3)|0x30;
60 else
61 rtnval=-EIO;
62
63 mutex_unlock(&sl->master->bus_mutex);
64
65 return rtnval;
66}
67
68static ssize_t w1_f12_write_output(
69 struct file *filp, struct kobject *kobj,
70 struct bin_attribute *bin_attr,
71 char *buf, loff_t off, size_t count)
72{
73 struct w1_slave *sl = kobj_to_w1_slave(kobj);
74 u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
75 u16 crc=0;
76 int i;
77 ssize_t rtnval=1;
78
79 if (count != 1 || off != 0)
80 return -EFAULT;
81
82 mutex_lock(&sl->master->bus_mutex);
83
84 if (w1_reset_select_slave(sl)) {
85 mutex_unlock(&sl->master->bus_mutex);
86 return -EIO;
87 }
88
89 w1_buf[3] = (((*buf)&3)<<5)|0x1F;
90 w1_write_block(sl->master, w1_buf, 4);
91 w1_read_block(sl->master, w1_buf+4, 2);
92 for (i=0; i<6; i++)
93 crc=crc16_byte(crc, w1_buf[i]);
94 if (crc==0xb001) /* good read? */
95 w1_write_8(sl->master, 0xFF);
96 else
97 rtnval=-EIO;
98
99 mutex_unlock(&sl->master->bus_mutex);
100 return rtnval;
101}
102
103#define NB_SYSFS_BIN_FILES 2
104static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
105 {
106 .attr = {
107 .name = "state",
108 .mode = S_IRUGO,
109 },
110 .size = 1,
111 .read = w1_f12_read_state,
112 },
113 {
114 .attr = {
115 .name = "output",
116 .mode = S_IRUGO | S_IWUSR | S_IWGRP,
117 },
118 .size = 1,
119 .write = w1_f12_write_output,
120 }
121};
122
123static int w1_f12_add_slave(struct w1_slave *sl)
124{
125 int err = 0;
126 int i;
127
128 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
129 err = sysfs_create_bin_file(
130 &sl->dev.kobj,
131 &(w1_f12_sysfs_bin_files[i]));
132 if (err)
133 while (--i >= 0)
134 sysfs_remove_bin_file(&sl->dev.kobj,
135 &(w1_f12_sysfs_bin_files[i]));
136 return err;
137}
138
139static void w1_f12_remove_slave(struct w1_slave *sl)
140{
141 int i;
142 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
143 sysfs_remove_bin_file(&sl->dev.kobj,
144 &(w1_f12_sysfs_bin_files[i]));
145}
146
147static struct w1_family_ops w1_f12_fops = {
148 .add_slave = w1_f12_add_slave,
149 .remove_slave = w1_f12_remove_slave,
150};
151
152static struct w1_family w1_family_12 = {
153 .fid = W1_FAMILY_DS2406,
154 .fops = &w1_f12_fops,
155};
156
157static int __init w1_f12_init(void)
158{
159 return w1_register_family(&w1_family_12);
160}
161
162static void __exit w1_f12_exit(void)
163{
164 w1_unregister_family(&w1_family_12);
165}
166
167module_init(w1_f12_init);
168module_exit(w1_f12_exit);