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>
29 #include <linux/delay.h>
34 #include "w1_family.h"
36 MODULE_LICENSE("GPL");
37 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
38 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
40 static u8 bad_roms[][9] = {
41 {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
45 static ssize_t w1_therm_read_name(struct device *, struct device_attribute *attr, char *);
46 static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
48 static struct w1_family_ops w1_therm_fops = {
49 .rname = &w1_therm_read_name,
50 .rbin = &w1_therm_read_bin,
53 static struct w1_family w1_therm_family_DS18S20 = {
54 .fid = W1_THERM_DS18S20,
55 .fops = &w1_therm_fops,
58 static struct w1_family w1_therm_family_DS18B20 = {
59 .fid = W1_THERM_DS18B20,
60 .fops = &w1_therm_fops,
62 static struct w1_family w1_therm_family_DS1822 = {
63 .fid = W1_THERM_DS1822,
64 .fops = &w1_therm_fops,
67 struct w1_therm_family_converter
73 int (*convert)(u8 rom[9]);
76 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
77 static inline int w1_DS18S20_convert_temp(u8 rom[9]);
79 static struct w1_therm_family_converter w1_therm_families[] = {
81 .fid = W1_THERM_DS18S20,
82 .f = &w1_therm_family_DS18S20,
83 .convert = w1_DS18S20_convert_temp
86 .fid = W1_THERM_DS1822,
87 .f = &w1_therm_family_DS1822,
88 .convert = w1_DS18B20_convert_temp
91 .fid = W1_THERM_DS18B20,
92 .f = &w1_therm_family_DS18B20,
93 .convert = w1_DS18B20_convert_temp
97 static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
99 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
101 return sprintf(buf, "%s\n", sl->name);
104 static inline int w1_DS18B20_convert_temp(u8 rom[9])
106 int t = (rom[1] << 8) | rom[0];
111 static inline int w1_DS18S20_convert_temp(u8 rom[9])
119 t = ((s32)rom[0] >> 1)*1000;
121 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
124 h = 1000*((s32)rom[7] - (s32)rom[6]);
131 static inline int w1_convert_temp(u8 rom[9], u8 fid)
135 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
136 if (w1_therm_families[i].fid == fid)
137 return w1_therm_families[i].convert(rom);
142 static int w1_therm_check_rom(u8 rom[9])
146 for (i=0; i<sizeof(bad_roms)/9; ++i)
147 if (!memcmp(bad_roms[i], rom, 9))
153 static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
155 struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
156 struct w1_slave, dev);
157 struct w1_master *dev = sl->master;
158 u8 rom[9], crc, verdict;
159 int i, max_trying = 10;
161 atomic_inc(&sl->refcnt);
162 smp_mb__after_atomic_inc();
163 if (down_interruptible(&sl->master->mutex)) {
168 if (off > W1_SLAVE_DATA_SIZE) {
172 if (off + count > W1_SLAVE_DATA_SIZE) {
177 memset(buf, 0, count);
178 memset(rom, 0, sizeof(rom));
184 while (max_trying--) {
185 if (!w1_reset_bus (dev)) {
187 u8 match[9] = {W1_MATCH_ROM, };
188 unsigned int tm = 750;
190 memcpy(&match[1], (u64 *) & sl->reg_num, 8);
192 w1_write_block(dev, match, 9);
194 w1_write_8(dev, W1_CONVERT_TEMP);
197 tm = msleep_interruptible(tm);
198 if (signal_pending(current))
199 flush_signals(current);
202 if (!w1_reset_bus (dev)) {
203 w1_write_block(dev, match, 9);
205 w1_write_8(dev, W1_READ_SCRATCHPAD);
206 if ((count = w1_read_block(dev, rom, 9)) != 9) {
207 dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
210 crc = w1_calc_crc8(rom, 8);
212 if (rom[8] == crc && rom[0])
218 if (!w1_therm_check_rom(rom))
222 for (i = 0; i < 9; ++i)
223 count += sprintf(buf + count, "%02x ", rom[i]);
224 count += sprintf(buf + count, ": crc=%02x %s\n",
225 crc, (verdict) ? "YES" : "NO");
227 memcpy(sl->rom, rom, sizeof(sl->rom));
229 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
231 for (i = 0; i < 9; ++i)
232 count += sprintf(buf + count, "%02x ", sl->rom[i]);
234 count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
238 smp_mb__before_atomic_inc();
239 atomic_dec(&sl->refcnt);
244 static int __init w1_therm_init(void)
248 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
249 err = w1_register_family(w1_therm_families[i].f);
251 w1_therm_families[i].broken = 1;
257 static void __exit w1_therm_fini(void)
261 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
262 if (!w1_therm_families[i].broken)
263 w1_unregister_family(w1_therm_families[i].f);
266 module_init(w1_therm_init);
267 module_exit(w1_therm_fini);