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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
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +030031#include "../w1.h"
32#include "../w1_io.h"
33#include "../w1_int.h"
34#include "../w1_family.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070045static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
46
Evgeniy Polyakovd2a4ef62005-08-11 17:27:50 +040047static struct bin_attribute w1_therm_bin_attr = {
48 .attr = {
49 .name = "w1_slave",
50 .mode = S_IRUGO,
51 .owner = THIS_MODULE,
52 },
53 .size = W1_SLAVE_DATA_SIZE,
54 .read = w1_therm_read_bin,
55};
56
57static int w1_therm_add_slave(struct w1_slave *sl)
58{
59 return sysfs_create_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
60}
61
62static void w1_therm_remove_slave(struct w1_slave *sl)
63{
64 sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
65}
66
Linus Torvalds1da177e2005-04-16 15:20:36 -070067static struct w1_family_ops w1_therm_fops = {
Evgeniy Polyakovd2a4ef62005-08-11 17:27:50 +040068 .add_slave = w1_therm_add_slave,
69 .remove_slave = w1_therm_remove_slave,
Linus Torvalds1da177e2005-04-16 15:20:36 -070070};
71
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040072static struct w1_family w1_therm_family_DS18S20 = {
73 .fid = W1_THERM_DS18S20,
74 .fops = &w1_therm_fops,
75};
76
77static struct w1_family w1_therm_family_DS18B20 = {
78 .fid = W1_THERM_DS18B20,
79 .fops = &w1_therm_fops,
80};
Evgeniy Polyakovd2a4ef62005-08-11 17:27:50 +040081
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040082static struct w1_family w1_therm_family_DS1822 = {
83 .fid = W1_THERM_DS1822,
84 .fops = &w1_therm_fops,
85};
86
87struct w1_therm_family_converter
88{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +040089 u8 broken;
90 u16 reserved;
91 struct w1_family *f;
92 int (*convert)(u8 rom[9]);
93};
94
95static inline int w1_DS18B20_convert_temp(u8 rom[9]);
96static inline int w1_DS18S20_convert_temp(u8 rom[9]);
97
98static struct w1_therm_family_converter w1_therm_families[] = {
99 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400100 .f = &w1_therm_family_DS18S20,
101 .convert = w1_DS18S20_convert_temp
102 },
103 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400104 .f = &w1_therm_family_DS1822,
105 .convert = w1_DS18B20_convert_temp
106 },
107 {
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400108 .f = &w1_therm_family_DS18B20,
109 .convert = w1_DS18B20_convert_temp
110 },
111};
112
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400113static inline int w1_DS18B20_convert_temp(u8 rom[9])
114{
115 int t = (rom[1] << 8) | rom[0];
116 t /= 16;
117 return t;
118}
119
120static inline int w1_DS18S20_convert_temp(u8 rom[9])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121{
122 int t, h;
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400123
124 if (!rom[7])
125 return 0;
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +0300126
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 if (rom[1] == 0)
128 t = ((s32)rom[0] >> 1)*1000;
129 else
130 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +0300131
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 t -= 250;
133 h = 1000*((s32)rom[7] - (s32)rom[6]);
134 h /= (s32)rom[7];
135 t += h;
136
137 return t;
138}
139
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400140static inline int w1_convert_temp(u8 rom[9], u8 fid)
141{
142 int i;
143
144 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
Evgeniy Polyakov4e470aa2005-05-20 22:50:33 +0400145 if (w1_therm_families[i].f->fid == fid)
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400146 return w1_therm_families[i].convert(rom);
147
148 return 0;
149}
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151static int w1_therm_check_rom(u8 rom[9])
152{
153 int i;
154
155 for (i=0; i<sizeof(bad_roms)/9; ++i)
156 if (!memcmp(bad_roms[i], rom, 9))
157 return 1;
158
159 return 0;
160}
161
162static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
163{
Evgeniy Polyakovdb2d0002005-08-11 17:27:49 +0400164 struct w1_slave *sl = kobj_to_w1_slave(kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 struct w1_master *dev = sl->master;
166 u8 rom[9], crc, verdict;
167 int i, max_trying = 10;
168
169 atomic_inc(&sl->refcnt);
170 smp_mb__after_atomic_inc();
171 if (down_interruptible(&sl->master->mutex)) {
172 count = 0;
173 goto out_dec;
174 }
175
176 if (off > W1_SLAVE_DATA_SIZE) {
177 count = 0;
178 goto out;
179 }
180 if (off + count > W1_SLAVE_DATA_SIZE) {
181 count = 0;
182 goto out;
183 }
184
185 memset(buf, 0, count);
186 memset(rom, 0, sizeof(rom));
187
188 count = 0;
189 verdict = 0;
190 crc = 0;
191
192 while (max_trying--) {
Evgeniy Polyakovea7d8f62005-08-11 17:27:49 +0400193 if (!w1_reset_select_slave(sl)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 int count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 unsigned int tm = 750;
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 w1_write_8(dev, W1_CONVERT_TEMP);
198
199 while (tm) {
200 tm = msleep_interruptible(tm);
201 if (signal_pending(current))
202 flush_signals(current);
203 }
204
Evgeniy Polyakovea7d8f62005-08-11 17:27:49 +0400205 if (!w1_reset_select_slave(sl)) {
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 w1_write_8(dev, W1_READ_SCRATCHPAD);
208 if ((count = w1_read_block(dev, rom, 9)) != 9) {
209 dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
210 }
211
212 crc = w1_calc_crc8(rom, 8);
213
214 if (rom[8] == crc && rom[0])
215 verdict = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 }
217 }
218
219 if (!w1_therm_check_rom(rom))
220 break;
221 }
222
223 for (i = 0; i < 9; ++i)
224 count += sprintf(buf + count, "%02x ", rom[i]);
225 count += sprintf(buf + count, ": crc=%02x %s\n",
226 crc, (verdict) ? "YES" : "NO");
227 if (verdict)
228 memcpy(sl->rom, rom, sizeof(sl->rom));
229 else
230 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
231
232 for (i = 0; i < 9; ++i)
233 count += sprintf(buf + count, "%02x ", sl->rom[i]);
Evgeniy Polyakovbd529cf2005-12-06 13:38:28 +0300234
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400235 count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236out:
237 up(&dev->mutex);
238out_dec:
239 smp_mb__before_atomic_inc();
240 atomic_dec(&sl->refcnt);
241
242 return count;
243}
244
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245static int __init w1_therm_init(void)
246{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400247 int err, i;
248
249 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
250 err = w1_register_family(w1_therm_families[i].f);
251 if (err)
252 w1_therm_families[i].broken = 1;
253 }
254
255 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258static void __exit w1_therm_fini(void)
259{
Evgeniy Polyakov718a5382005-04-17 22:58:14 +0400260 int i;
261
262 for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
263 if (!w1_therm_families[i].broken)
264 w1_unregister_family(w1_therm_families[i].f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267module_init(w1_therm_init);
268module_exit(w1_therm_fini);