Merge branch 'async-tx-for-linus' of git://lost.foo-projects.org/~dwillia2/git/iop...
[linux-2.6] / drivers / w1 / slaves / w1_therm.c
1 /*
2  *      w1_therm.c
3  *
4  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5  *
6  *
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/sched.h>
28 #include <linux/device.h>
29 #include <linux/types.h>
30 #include <linux/delay.h>
31
32 #include "../w1.h"
33 #include "../w1_int.h"
34 #include "../w1_family.h"
35
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.");
39
40 static u8 bad_roms[][9] = {
41                                 {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87},
42                                 {}
43                         };
44
45 static ssize_t w1_therm_read_bin(struct kobject *, struct bin_attribute *,
46                                  char *, loff_t, size_t);
47
48 static struct bin_attribute w1_therm_bin_attr = {
49         .attr = {
50                 .name = "w1_slave",
51                 .mode = S_IRUGO,
52         },
53         .size = W1_SLAVE_DATA_SIZE,
54         .read = w1_therm_read_bin,
55 };
56
57 static 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
62 static void w1_therm_remove_slave(struct w1_slave *sl)
63 {
64         sysfs_remove_bin_file(&sl->dev.kobj, &w1_therm_bin_attr);
65 }
66
67 static struct w1_family_ops w1_therm_fops = {
68         .add_slave      = w1_therm_add_slave,
69         .remove_slave   = w1_therm_remove_slave,
70 };
71
72 static struct w1_family w1_therm_family_DS18S20 = {
73         .fid = W1_THERM_DS18S20,
74         .fops = &w1_therm_fops,
75 };
76
77 static struct w1_family w1_therm_family_DS18B20 = {
78         .fid = W1_THERM_DS18B20,
79         .fops = &w1_therm_fops,
80 };
81
82 static struct w1_family w1_therm_family_DS1822 = {
83         .fid = W1_THERM_DS1822,
84         .fops = &w1_therm_fops,
85 };
86
87 struct w1_therm_family_converter
88 {
89         u8                      broken;
90         u16                     reserved;
91         struct w1_family        *f;
92         int                     (*convert)(u8 rom[9]);
93 };
94
95 /* The return value is millidegrees Centigrade. */
96 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
97 static inline int w1_DS18S20_convert_temp(u8 rom[9]);
98
99 static struct w1_therm_family_converter w1_therm_families[] = {
100         {
101                 .f              = &w1_therm_family_DS18S20,
102                 .convert        = w1_DS18S20_convert_temp
103         },
104         {
105                 .f              = &w1_therm_family_DS1822,
106                 .convert        = w1_DS18B20_convert_temp
107         },
108         {
109                 .f              = &w1_therm_family_DS18B20,
110                 .convert        = w1_DS18B20_convert_temp
111         },
112 };
113
114 static inline int w1_DS18B20_convert_temp(u8 rom[9])
115 {
116         s16 t = (rom[1] << 8) | rom[0];
117         t = t*1000/16;
118         return t;
119 }
120
121 static inline int w1_DS18S20_convert_temp(u8 rom[9])
122 {
123         int t, h;
124
125         if (!rom[7])
126                 return 0;
127
128         if (rom[1] == 0)
129                 t = ((s32)rom[0] >> 1)*1000;
130         else
131                 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
132
133         t -= 250;
134         h = 1000*((s32)rom[7] - (s32)rom[6]);
135         h /= (s32)rom[7];
136         t += h;
137
138         return t;
139 }
140
141 static inline int w1_convert_temp(u8 rom[9], u8 fid)
142 {
143         int i;
144
145         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
146                 if (w1_therm_families[i].f->fid == fid)
147                         return w1_therm_families[i].convert(rom);
148
149         return 0;
150 }
151
152 static int w1_therm_check_rom(u8 rom[9])
153 {
154         int i;
155
156         for (i=0; i<sizeof(bad_roms)/9; ++i)
157                 if (!memcmp(bad_roms[i], rom, 9))
158                         return 1;
159
160         return 0;
161 }
162
163 static ssize_t w1_therm_read_bin(struct kobject *kobj,
164                                  struct bin_attribute *bin_attr,
165                                  char *buf, loff_t off, size_t count)
166 {
167         struct w1_slave *sl = kobj_to_w1_slave(kobj);
168         struct w1_master *dev = sl->master;
169         u8 rom[9], crc, verdict;
170         int i, max_trying = 10;
171
172         mutex_lock(&sl->master->mutex);
173
174         if (off > W1_SLAVE_DATA_SIZE) {
175                 count = 0;
176                 goto out;
177         }
178         if (off + count > W1_SLAVE_DATA_SIZE) {
179                 count = 0;
180                 goto out;
181         }
182
183         memset(buf, 0, count);
184         memset(rom, 0, sizeof(rom));
185
186         count = 0;
187         verdict = 0;
188         crc = 0;
189
190         while (max_trying--) {
191                 if (!w1_reset_select_slave(sl)) {
192                         int count = 0;
193                         unsigned int tm = 750;
194
195                         w1_write_8(dev, W1_CONVERT_TEMP);
196
197                         msleep(tm);
198
199                         if (!w1_reset_select_slave(sl)) {
200
201                                 w1_write_8(dev, W1_READ_SCRATCHPAD);
202                                 if ((count = w1_read_block(dev, rom, 9)) != 9) {
203                                         dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
204                                 }
205
206                                 crc = w1_calc_crc8(rom, 8);
207
208                                 if (rom[8] == crc)
209                                         verdict = 1;
210                         }
211                 }
212
213                 if (!w1_therm_check_rom(rom))
214                         break;
215         }
216
217         for (i = 0; i < 9; ++i)
218                 count += sprintf(buf + count, "%02x ", rom[i]);
219         count += sprintf(buf + count, ": crc=%02x %s\n",
220                            crc, (verdict) ? "YES" : "NO");
221         if (verdict)
222                 memcpy(sl->rom, rom, sizeof(sl->rom));
223         else
224                 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
225
226         for (i = 0; i < 9; ++i)
227                 count += sprintf(buf + count, "%02x ", sl->rom[i]);
228
229         count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
230 out:
231         mutex_unlock(&dev->mutex);
232
233         return count;
234 }
235
236 static int __init w1_therm_init(void)
237 {
238         int err, i;
239
240         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
241                 err = w1_register_family(w1_therm_families[i].f);
242                 if (err)
243                         w1_therm_families[i].broken = 1;
244         }
245
246         return 0;
247 }
248
249 static void __exit w1_therm_fini(void)
250 {
251         int i;
252
253         for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i)
254                 if (!w1_therm_families[i].broken)
255                         w1_unregister_family(w1_therm_families[i].f);
256 }
257
258 module_init(w1_therm_init);
259 module_exit(w1_therm_fini);