1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * w1_ds2406.c - w1 family 12 (DS2406) driver
4 * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
5 *
6 * Copyright (c) 2014 Scott Alfter <scott@alfter.us>
7 */
8
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 #include <linux/crc16.h>
17
18 #include <linux/w1.h>
19
20 #define W1_FAMILY_DS2406 0x12
21
22 #define W1_F12_FUNC_READ_STATUS 0xAA
23 #define W1_F12_FUNC_WRITE_STATUS 0x55
24
w1_f12_read_state(struct file * filp,struct kobject * kobj,const struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)25 static ssize_t w1_f12_read_state(
26 struct file *filp, struct kobject *kobj,
27 const struct bin_attribute *bin_attr,
28 char *buf, loff_t off, size_t count)
29 {
30 u8 w1_buf[6] = {W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
31 struct w1_slave *sl = kobj_to_w1_slave(kobj);
32 ssize_t rtnval = 1;
33
34 if (off != 0)
35 return 0;
36 if (!buf)
37 return -EINVAL;
38
39 mutex_lock(&sl->master->bus_mutex);
40
41 if (w1_reset_select_slave(sl)) {
42 mutex_unlock(&sl->master->bus_mutex);
43 return -EIO;
44 }
45
46 w1_write_block(sl->master, w1_buf, 3);
47 w1_read_block(sl->master, w1_buf+3, 3);
48 if (crc16(0, w1_buf, sizeof(w1_buf)) == 0xb001) /* good read? */
49 *buf = ((w1_buf[3]>>5)&3)|0x30;
50 else
51 rtnval = -EIO;
52
53 mutex_unlock(&sl->master->bus_mutex);
54
55 return rtnval;
56 }
57
w1_f12_write_output(struct file * filp,struct kobject * kobj,const struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)58 static ssize_t w1_f12_write_output(
59 struct file *filp, struct kobject *kobj,
60 const struct bin_attribute *bin_attr,
61 char *buf, loff_t off, size_t count)
62 {
63 struct w1_slave *sl = kobj_to_w1_slave(kobj);
64 u8 w1_buf[6] = {W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
65 ssize_t rtnval = 1;
66
67 if (count != 1 || off != 0)
68 return -EFAULT;
69
70 mutex_lock(&sl->master->bus_mutex);
71
72 if (w1_reset_select_slave(sl)) {
73 mutex_unlock(&sl->master->bus_mutex);
74 return -EIO;
75 }
76
77 w1_buf[3] = (((*buf)&3)<<5)|0x1F;
78 w1_write_block(sl->master, w1_buf, 4);
79 w1_read_block(sl->master, w1_buf+4, 2);
80 if (crc16(0, w1_buf, sizeof(w1_buf)) == 0xb001) /* good read? */
81 w1_write_8(sl->master, 0xFF);
82 else
83 rtnval = -EIO;
84
85 mutex_unlock(&sl->master->bus_mutex);
86 return rtnval;
87 }
88
89 #define NB_SYSFS_BIN_FILES 2
90 static const struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
91 {
92 .attr = {
93 .name = "state",
94 .mode = 0444,
95 },
96 .size = 1,
97 .read = w1_f12_read_state,
98 },
99 {
100 .attr = {
101 .name = "output",
102 .mode = 0664,
103 },
104 .size = 1,
105 .write = w1_f12_write_output,
106 }
107 };
108
w1_f12_add_slave(struct w1_slave * sl)109 static int w1_f12_add_slave(struct w1_slave *sl)
110 {
111 int err = 0;
112 int i;
113
114 for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
115 err = sysfs_create_bin_file(
116 &sl->dev.kobj,
117 &(w1_f12_sysfs_bin_files[i]));
118 if (err)
119 while (--i >= 0)
120 sysfs_remove_bin_file(&sl->dev.kobj,
121 &(w1_f12_sysfs_bin_files[i]));
122 return err;
123 }
124
w1_f12_remove_slave(struct w1_slave * sl)125 static void w1_f12_remove_slave(struct w1_slave *sl)
126 {
127 int i;
128
129 for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
130 sysfs_remove_bin_file(&sl->dev.kobj,
131 &(w1_f12_sysfs_bin_files[i]));
132 }
133
134 static const struct w1_family_ops w1_f12_fops = {
135 .add_slave = w1_f12_add_slave,
136 .remove_slave = w1_f12_remove_slave,
137 };
138
139 static struct w1_family w1_family_12 = {
140 .fid = W1_FAMILY_DS2406,
141 .fops = &w1_f12_fops,
142 };
143 module_w1_family(w1_family_12);
144
145 MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
146 MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");
147 MODULE_LICENSE("GPL");
148