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_temp(struct device *, struct device_attribute *attr, char *);
47 static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
49 static struct w1_family_ops w1_therm_fops = {
50 .rname = &w1_therm_read_name,
51 .rbin = &w1_therm_read_bin,
52 .rval = &w1_therm_read_temp,
53 .rvalname = "temp1_input",
56 static struct w1_family w1_therm_family_DS18S20 = {
57 .fid = W1_THERM_DS18S20,
58 .fops = &w1_therm_fops,
61 static struct w1_family w1_therm_family_DS18B20 = {
62 .fid = W1_THERM_DS18B20,
63 .fops = &w1_therm_fops,
65 static struct w1_family w1_therm_family_DS1822 = {
66 .fid = W1_THERM_DS1822,
67 .fops = &w1_therm_fops,
70 struct w1_therm_family_converter
76 int (*convert)(u8 rom[9]);
79 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
80 static inline int w1_DS18S20_convert_temp(u8 rom[9]);
82 static struct w1_therm_family_converter w1_therm_families[] = {
84 .fid = W1_THERM_DS18S20,
85 .f = &w1_therm_family_DS18S20,
86 .convert = w1_DS18S20_convert_temp
89 .fid = W1_THERM_DS1822,
90 .f = &w1_therm_family_DS1822,
91 .convert = w1_DS18B20_convert_temp
94 .fid = W1_THERM_DS18B20,
95 .f = &w1_therm_family_DS18B20,
96 .convert = w1_DS18B20_convert_temp
100 static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
102 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
104 return sprintf(buf, "%s\n", sl->name);
107 static inline int w1_DS18B20_convert_temp(u8 rom[9])
109 int t = (rom[1] << 8) | rom[0];
114 static inline int w1_DS18S20_convert_temp(u8 rom[9])
122 t = ((s32)rom[0] >> 1)*1000;
124 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
127 h = 1000*((s32)rom[7] - (s32)rom[6]);
134 static inline int w1_convert_temp(u8 rom[9], u8 fid)
138 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
139 if (w1_therm_families[i].fid == fid)
140 return w1_therm_families[i].convert(rom);
145 static ssize_t w1_therm_read_temp(struct device *dev, struct device_attribute *attr, char *buf)
147 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
149 return sprintf(buf, "%d\n", w1_convert_temp(sl->rom, sl->family->fid));
152 static int w1_therm_check_rom(u8 rom[9])
156 for (i=0; i<sizeof(bad_roms)/9; ++i)
157 if (!memcmp(bad_roms[i], rom, 9))
163 static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
165 struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
166 struct w1_slave, dev);
167 struct w1_master *dev = sl->master;
168 u8 rom[9], crc, verdict;
169 int i, max_trying = 10;
171 atomic_inc(&sl->refcnt);
172 smp_mb__after_atomic_inc();
173 if (down_interruptible(&sl->master->mutex)) {
178 if (off > W1_SLAVE_DATA_SIZE) {
182 if (off + count > W1_SLAVE_DATA_SIZE) {
187 memset(buf, 0, count);
188 memset(rom, 0, sizeof(rom));
194 while (max_trying--) {
195 if (!w1_reset_bus (dev)) {
197 u8 match[9] = {W1_MATCH_ROM, };
198 unsigned int tm = 750;
200 memcpy(&match[1], (u64 *) & sl->reg_num, 8);
202 w1_write_block(dev, match, 9);
204 w1_write_8(dev, W1_CONVERT_TEMP);
207 tm = msleep_interruptible(tm);
208 if (signal_pending(current))
209 flush_signals(current);
212 if (!w1_reset_bus (dev)) {
213 w1_write_block(dev, match, 9);
215 w1_write_8(dev, W1_READ_SCRATCHPAD);
216 if ((count = w1_read_block(dev, rom, 9)) != 9) {
217 dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
220 crc = w1_calc_crc8(rom, 8);
222 if (rom[8] == crc && rom[0])
228 if (!w1_therm_check_rom(rom))
232 for (i = 0; i < 9; ++i)
233 count += sprintf(buf + count, "%02x ", rom[i]);
234 count += sprintf(buf + count, ": crc=%02x %s\n",
235 crc, (verdict) ? "YES" : "NO");
237 memcpy(sl->rom, rom, sizeof(sl->rom));
239 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
241 for (i = 0; i < 9; ++i)
242 count += sprintf(buf + count, "%02x ", sl->rom[i]);
244 count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
248 smp_mb__before_atomic_inc();
249 atomic_dec(&sl->refcnt);
254 static int __init w1_therm_init(void)
258 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
259 err = w1_register_family(w1_therm_families[i].f);
261 w1_therm_families[i].broken = 1;
267 static void __exit w1_therm_fini(void)
271 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
272 if (!w1_therm_families[i].broken)
273 w1_unregister_family(w1_therm_families[i].f);
276 module_init(w1_therm_init);
277 module_exit(w1_therm_fini);