[PATCH] Cleanup patch for process freezing
[linux-2.6.git] / drivers / w1 / 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/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
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_name(struct device *, struct device_attribute *attr, char *);
46 static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
47
48 static struct w1_family_ops w1_therm_fops = {
49         .rname = &w1_therm_read_name,
50         .rbin = &w1_therm_read_bin,
51 };
52
53 static struct w1_family w1_therm_family_DS18S20 = {
54         .fid = W1_THERM_DS18S20,
55         .fops = &w1_therm_fops,
56 };
57
58 static struct w1_family w1_therm_family_DS18B20 = {
59         .fid = W1_THERM_DS18B20,
60         .fops = &w1_therm_fops,
61 };
62 static struct w1_family w1_therm_family_DS1822 = {
63         .fid = W1_THERM_DS1822,
64         .fops = &w1_therm_fops,
65 };
66
67 struct w1_therm_family_converter
68 {
69         u8                      broken;
70         u16                     reserved;
71         struct w1_family        *f;
72         int                     (*convert)(u8 rom[9]);
73 };
74
75 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
76 static inline int w1_DS18S20_convert_temp(u8 rom[9]);
77
78 static struct w1_therm_family_converter w1_therm_families[] = {
79         {
80                 .f              = &w1_therm_family_DS18S20,
81                 .convert        = w1_DS18S20_convert_temp
82         },
83         {
84                 .f              = &w1_therm_family_DS1822,
85                 .convert        = w1_DS18B20_convert_temp
86         },
87         {
88                 .f              = &w1_therm_family_DS18B20,
89                 .convert        = w1_DS18B20_convert_temp
90         },
91 };
92
93 static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
94 {
95         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
96
97         return sprintf(buf, "%s\n", sl->name);
98 }
99
100 static inline int w1_DS18B20_convert_temp(u8 rom[9])
101 {
102         int t = (rom[1] << 8) | rom[0];
103         t /= 16;
104         return t;
105 }
106
107 static inline int w1_DS18S20_convert_temp(u8 rom[9])
108 {
109         int t, h;
110
111         if (!rom[7])
112                 return 0;
113         
114         if (rom[1] == 0)
115                 t = ((s32)rom[0] >> 1)*1000;
116         else
117                 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
118         
119         t -= 250;
120         h = 1000*((s32)rom[7] - (s32)rom[6]);
121         h /= (s32)rom[7];
122         t += h;
123
124         return t;
125 }
126
127 static inline int w1_convert_temp(u8 rom[9], u8 fid)
128 {
129         int i;
130
131         for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
132                 if (w1_therm_families[i].f->fid == fid)
133                         return w1_therm_families[i].convert(rom);
134
135         return 0;
136 }
137
138 static int w1_therm_check_rom(u8 rom[9])
139 {
140         int i;
141
142         for (i=0; i<sizeof(bad_roms)/9; ++i)
143                 if (!memcmp(bad_roms[i], rom, 9))
144                         return 1;
145
146         return 0;
147 }
148
149 static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
150 {
151         struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
152                                            struct w1_slave, dev);
153         struct w1_master *dev = sl->master;
154         u8 rom[9], crc, verdict;
155         int i, max_trying = 10;
156
157         atomic_inc(&sl->refcnt);
158         smp_mb__after_atomic_inc();
159         if (down_interruptible(&sl->master->mutex)) {
160                 count = 0;
161                 goto out_dec;
162         }
163
164         if (off > W1_SLAVE_DATA_SIZE) {
165                 count = 0;
166                 goto out;
167         }
168         if (off + count > W1_SLAVE_DATA_SIZE) {
169                 count = 0;
170                 goto out;
171         }
172
173         memset(buf, 0, count);
174         memset(rom, 0, sizeof(rom));
175
176         count = 0;
177         verdict = 0;
178         crc = 0;
179
180         while (max_trying--) {
181                 if (!w1_reset_bus (dev)) {
182                         int count = 0;
183                         u8 match[9] = {W1_MATCH_ROM, };
184                         unsigned int tm = 750;
185
186                         memcpy(&match[1], (u64 *) & sl->reg_num, 8);
187
188                         w1_write_block(dev, match, 9);
189
190                         w1_write_8(dev, W1_CONVERT_TEMP);
191
192                         while (tm) {
193                                 tm = msleep_interruptible(tm);
194                                 if (signal_pending(current))
195                                         flush_signals(current);
196                         }
197
198                         if (!w1_reset_bus (dev)) {
199                                 w1_write_block(dev, match, 9);
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 && rom[0])
209                                         verdict = 1;
210
211                         }
212                 }
213
214                 if (!w1_therm_check_rom(rom))
215                         break;
216         }
217
218         for (i = 0; i < 9; ++i)
219                 count += sprintf(buf + count, "%02x ", rom[i]);
220         count += sprintf(buf + count, ": crc=%02x %s\n",
221                            crc, (verdict) ? "YES" : "NO");
222         if (verdict)
223                 memcpy(sl->rom, rom, sizeof(sl->rom));
224         else
225                 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
226
227         for (i = 0; i < 9; ++i)
228                 count += sprintf(buf + count, "%02x ", sl->rom[i]);
229         
230         count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
231 out:
232         up(&dev->mutex);
233 out_dec:
234         smp_mb__before_atomic_inc();
235         atomic_dec(&sl->refcnt);
236
237         return count;
238 }
239
240 static int __init w1_therm_init(void)
241 {
242         int err, i;
243
244         for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i) {
245                 err = w1_register_family(w1_therm_families[i].f);
246                 if (err)
247                         w1_therm_families[i].broken = 1;
248         }
249
250         return 0;
251 }
252
253 static void __exit w1_therm_fini(void)
254 {
255         int i;
256
257         for (i=0; i<sizeof(w1_therm_families)/sizeof(w1_therm_families[0]); ++i)
258                 if (!w1_therm_families[i].broken)
259                         w1_unregister_family(w1_therm_families[i].f);
260 }
261
262 module_init(w1_therm_init);
263 module_exit(w1_therm_fini);