blob: 2ed0e0f4826823a1040d029dea4caf5c3b16f228 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Evgeniy Polyakov77859252005-05-20 22:33:25 +04002 * w1_therm.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Evgeniy Polyakov77859252005-05-20 22:33:25 +04005 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
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.
11 *
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.
16 *
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
20 */
21
22#include <asm/types.h>
23
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>
30
31#include "w1.h"
32#include "w1_io.h"
33#include "w1_int.h"
34#include "w1_family.h"
35
36MODULE_LICENSE("GPL");
37MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
38MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family.");
39
40static u8 bad_roms[][9] = {
Evgeniy Polyakov77859252005-05-20 22:33:25 +040041 {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 {}
43 };
44
Yani Ioannou060b8842005-05-17 06:44:04 -040045static ssize_t w1_therm_read_name(struct device *, struct device_attribute *attr, char *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070046static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
47
48static struct w1_family_ops w1_therm_fops = {
49 .rname = &w1_therm_read_name,
50 .rbin = &w1_therm_read_bin,
Linus Torvalds1da177e2005-04-16 15:20:36 -070051};
52
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040053static struct w1_family w1_therm_family_DS18S20 = {
54 .fid = W1_THERM_DS18S20,
55 .fops = &w1_therm_fops,
56};
57
58static struct w1_family w1_therm_family_DS18B20 = {
59 .fid = W1_THERM_DS18B20,
60 .fops = &w1_therm_fops,
61};
62static struct w1_family w1_therm_family_DS1822 = {
63 .fid = W1_THERM_DS1822,
64 .fops = &w1_therm_fops,
65};
66
67struct w1_therm_family_converter
68{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040069 u8 broken;
70 u16 reserved;
71 struct w1_family *f;
72 int (*convert)(u8 rom[9]);
73};
74
75static inline int w1_DS18B20_convert_temp(u8 rom[9]);
76static inline int w1_DS18S20_convert_temp(u8 rom[9]);
77
78static struct w1_therm_family_converter w1_therm_families[] = {
79 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040080 .f = &w1_therm_family_DS18S20,
81 .convert = w1_DS18S20_convert_temp
82 },
83 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040084 .f = &w1_therm_family_DS1822,
85 .convert = w1_DS18B20_convert_temp
86 },
87 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040088 .f = &w1_therm_family_DS18B20,
89 .convert = w1_DS18B20_convert_temp
90 },
91};
92
Yani Ioannou060b8842005-05-17 06:44:04 -040093static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -070094{
Evgeniy Polyakovdb2d0002005-08-11 17:27:49 +040095 struct w1_slave *sl = dev_to_w1_slave(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 return sprintf(buf, "%s\n", sl->name);
97}
98
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040099static inline int w1_DS18B20_convert_temp(u8 rom[9])
100{
101 int t = (rom[1] << 8) | rom[0];
102 t /= 16;
103 return t;
104}
105
106static inline int w1_DS18S20_convert_temp(u8 rom[9])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
108 int t, h;
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400109
110 if (!rom[7])
111 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112
113 if (rom[1] == 0)
114 t = ((s32)rom[0] >> 1)*1000;
115 else
116 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
117
118 t -= 250;
119 h = 1000*((s32)rom[7] - (s32)rom[6]);
120 h /= (s32)rom[7];
121 t += h;
122
123 return t;
124}
125
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400126static inline int w1_convert_temp(u8 rom[9], u8 fid)
127{
128 int i;
129
130 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
Evgeniy Polyakov4e470aa2005-05-20 22:50:33 +0400131 if (w1_therm_families[i].f->fid == fid)
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400132 return w1_therm_families[i].convert(rom);
133
134 return 0;
135}
136
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137static int w1_therm_check_rom(u8 rom[9])
138{
139 int i;
140
141 for (i=0; i<sizeof(bad_roms)/9; ++i)
142 if (!memcmp(bad_roms[i], rom, 9))
143 return 1;
144
145 return 0;
146}
147
148static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
149{
Evgeniy Polyakovdb2d0002005-08-11 17:27:49 +0400150 struct w1_slave *sl = kobj_to_w1_slave(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 struct w1_master *dev = sl->master;
152 u8 rom[9], crc, verdict;
153 int i, max_trying = 10;
154
155 atomic_inc(&sl->refcnt);
156 smp_mb__after_atomic_inc();
157 if (down_interruptible(&sl->master->mutex)) {
158 count = 0;
159 goto out_dec;
160 }
161
162 if (off > W1_SLAVE_DATA_SIZE) {
163 count = 0;
164 goto out;
165 }
166 if (off + count > W1_SLAVE_DATA_SIZE) {
167 count = 0;
168 goto out;
169 }
170
171 memset(buf, 0, count);
172 memset(rom, 0, sizeof(rom));
173
174 count = 0;
175 verdict = 0;
176 crc = 0;
177
178 while (max_trying--) {
Evgeniy Polyakovea7d8f62005-08-11 17:27:49 +0400179 if (!w1_reset_select_slave(sl)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 int count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 unsigned int tm = 750;
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 w1_write_8(dev, W1_CONVERT_TEMP);
184
185 while (tm) {
186 tm = msleep_interruptible(tm);
187 if (signal_pending(current))
188 flush_signals(current);
189 }
190
Evgeniy Polyakovea7d8f62005-08-11 17:27:49 +0400191 if (!w1_reset_select_slave(sl)) {
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400192
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 w1_write_8(dev, W1_READ_SCRATCHPAD);
194 if ((count = w1_read_block(dev, rom, 9)) != 9) {
195 dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
196 }
197
198 crc = w1_calc_crc8(rom, 8);
199
200 if (rom[8] == crc && rom[0])
201 verdict = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
203 }
204
205 if (!w1_therm_check_rom(rom))
206 break;
207 }
208
209 for (i = 0; i < 9; ++i)
210 count += sprintf(buf + count, "%02x ", rom[i]);
211 count += sprintf(buf + count, ": crc=%02x %s\n",
212 crc, (verdict) ? "YES" : "NO");
213 if (verdict)
214 memcpy(sl->rom, rom, sizeof(sl->rom));
215 else
216 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
217
218 for (i = 0; i < 9; ++i)
219 count += sprintf(buf + count, "%02x ", sl->rom[i]);
220
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400221 count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222out:
223 up(&dev->mutex);
224out_dec:
225 smp_mb__before_atomic_inc();
226 atomic_dec(&sl->refcnt);
227
228 return count;
229}
230
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231static int __init w1_therm_init(void)
232{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400233 int err, i;
234
235 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
236 err = w1_register_family(w1_therm_families[i].f);
237 if (err)
238 w1_therm_families[i].broken = 1;
239 }
240
241 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
244static void __exit w1_therm_fini(void)
245{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400246 int i;
247
248 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
249 if (!w1_therm_families[i].broken)
250 w1_unregister_family(w1_therm_families[i].f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251}
252
253module_init(w1_therm_init);
254module_exit(w1_therm_fini);