4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the therms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 #include <asm/types.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/moduleparam.h>
27 #include <linux/device.h>
28 #include <linux/types.h>
33 #include "w1_family.h"
35 MODULE_LICENSE("GPL");
36 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
37 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
39 static ssize_t w1_therm_read_name(struct device *, char *);
40 static ssize_t w1_therm_read_temp(struct device *, char *);
41 static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
43 static struct w1_family_ops w1_therm_fops = {
44 .rname = &w1_therm_read_name,
45 .rbin = &w1_therm_read_bin,
46 .rval = &w1_therm_read_temp,
47 .rvalname = "temp1_input",
50 static ssize_t w1_therm_read_name(struct device *dev, char *buf)
52 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
54 return sprintf(buf, "%s\n", sl->name);
57 static ssize_t w1_therm_read_temp(struct device *dev, char *buf)
59 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
63 * Must be more precise.
66 temp <<= sl->rom[1] / 2;
67 temp |= sl->rom[0] / 2;
69 return sprintf(buf, "%d\n", temp * 1000);
72 static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
74 struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
75 struct w1_slave, dev);
76 struct w1_master *dev = sl->master;
77 u8 rom[9], crc, verdict;
82 atomic_inc(&sl->refcnt);
83 if (down_interruptible(&sl->master->mutex)) {
88 if (off > W1_SLAVE_DATA_SIZE) {
92 if (off + count > W1_SLAVE_DATA_SIZE)
93 count = W1_SLAVE_DATA_SIZE - off;
97 memset(buf, 0, count);
98 memset(rom, 0, sizeof(rom));
103 if (!w1_reset_bus(dev)) {
104 u64 id = *(u64 *) & sl->reg_num;
107 w1_write_8(dev, W1_MATCH_ROM);
108 for (i = 0; i < 8; ++i)
109 w1_write_8(dev, (id >> i * 8) & 0xff);
111 w1_write_8(dev, W1_CONVERT_TEMP);
113 while (dev->bus_master->read_bit(dev->bus_master->data) == 0
120 if (!w1_reset_bus(dev)) {
121 w1_write_8(dev, W1_MATCH_ROM);
122 for (i = 0; i < 8; ++i)
124 (id >> i * 8) & 0xff);
126 w1_write_8(dev, W1_READ_SCRATCHPAD);
127 for (i = 0; i < 9; ++i)
128 rom[i] = w1_read_8(dev);
130 crc = w1_calc_crc8(rom, 8);
132 if (rom[8] == crc && rom[0])
138 "18S20 doesn't respond to CONVERT_TEMP.\n");
141 for (i = 0; i < 9; ++i)
142 count += snprintf(buf + count, icount - count, "%02x ", rom[i]);
143 count += snprintf(buf + count, icount - count, ": crc=%02x %s\n",
144 crc, (verdict) ? "YES" : "NO");
146 memcpy(sl->rom, rom, sizeof(sl->rom));
147 for (i = 0; i < 9; ++i)
148 count += snprintf(buf + count, icount - count, "%02x ", sl->rom[i]);
150 temp <<= sl->rom[1] / 2;
151 temp |= sl->rom[0] / 2;
152 count += snprintf(buf + count, icount - count, "t=%u\n", temp);
156 atomic_dec(&sl->refcnt);
161 static struct w1_family w1_therm_family = {
162 .fid = W1_FAMILY_THERM,
163 .fops = &w1_therm_fops,
166 static int __init w1_therm_init(void)
168 return w1_register_family(&w1_therm_family);
171 static void __exit w1_therm_fini(void)
173 w1_unregister_family(&w1_therm_family);
176 module_init(w1_therm_init);
177 module_exit(w1_therm_fini);