84e8043a4499f8bd0ebb6462e1f21307ff1ce659
[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_temp(struct device *, struct device_attribute *attr, char *);
47 static ssize_t w1_therm_read_bin(struct kobject *, char *, loff_t, size_t);
48
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",
54 };
55
56 static struct w1_family w1_therm_family_DS18S20 = {
57         .fid = W1_THERM_DS18S20,
58         .fops = &w1_therm_fops,
59 };
60
61 static struct w1_family w1_therm_family_DS18B20 = {
62         .fid = W1_THERM_DS18B20,
63         .fops = &w1_therm_fops,
64 };
65 static struct w1_family w1_therm_family_DS1822 = {
66         .fid = W1_THERM_DS1822,
67         .fops = &w1_therm_fops,
68 };
69
70 struct w1_therm_family_converter
71 {
72         u8                      fid;
73         u8                      broken;
74         u16                     reserved;
75         struct w1_family        *f;
76         int                     (*convert)(u8 rom[9]);
77 };
78
79 static inline int w1_DS18B20_convert_temp(u8 rom[9]);
80 static inline int w1_DS18S20_convert_temp(u8 rom[9]);
81
82 static struct w1_therm_family_converter w1_therm_families[] = {
83         {
84                 .fid            = W1_THERM_DS18S20,
85                 .f              = &w1_therm_family_DS18S20,
86                 .convert        = w1_DS18S20_convert_temp
87         },
88         {
89                 .fid            = W1_THERM_DS1822,
90                 .f              = &w1_therm_family_DS1822,
91                 .convert        = w1_DS18B20_convert_temp
92         },
93         {
94                 .fid            = W1_THERM_DS18B20,
95                 .f              = &w1_therm_family_DS18B20,
96                 .convert        = w1_DS18B20_convert_temp
97         },
98 };
99
100 static ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
101 {
102         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
103
104         return sprintf(buf, "%s\n", sl->name);
105 }
106
107 static inline int w1_DS18B20_convert_temp(u8 rom[9])
108 {
109         int t = (rom[1] << 8) | rom[0];
110         t /= 16;
111         return t;
112 }
113
114 static inline int w1_DS18S20_convert_temp(u8 rom[9])
115 {
116         int t, h;
117
118         if (!rom[7])
119                 return 0;
120         
121         if (rom[1] == 0)
122                 t = ((s32)rom[0] >> 1)*1000;
123         else
124                 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
125         
126         t -= 250;
127         h = 1000*((s32)rom[7] - (s32)rom[6]);
128         h /= (s32)rom[7];
129         t += h;
130
131         return t;
132 }
133
134 static inline int w1_convert_temp(u8 rom[9], u8 fid)
135 {
136         int i;
137
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);
141
142         return 0;
143 }
144
145 static ssize_t w1_therm_read_temp(struct device *dev, struct device_attribute *attr, char *buf)
146 {
147         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
148
149         return sprintf(buf, "%d\n", w1_convert_temp(sl->rom, sl->family->fid));
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, char *buf, loff_t off, size_t count)
164 {
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;
170
171         atomic_inc(&sl->refcnt);
172         smp_mb__after_atomic_inc();
173         if (down_interruptible(&sl->master->mutex)) {
174                 count = 0;
175                 goto out_dec;
176         }
177
178         if (off > W1_SLAVE_DATA_SIZE) {
179                 count = 0;
180                 goto out;
181         }
182         if (off + count > W1_SLAVE_DATA_SIZE) {
183                 count = 0;
184                 goto out;
185         }
186
187         memset(buf, 0, count);
188         memset(rom, 0, sizeof(rom));
189
190         count = 0;
191         verdict = 0;
192         crc = 0;
193
194         while (max_trying--) {
195                 if (!w1_reset_bus (dev)) {
196                         int count = 0;
197                         u8 match[9] = {W1_MATCH_ROM, };
198                         unsigned int tm = 750;
199
200                         memcpy(&match[1], (u64 *) & sl->reg_num, 8);
201                         
202                         w1_write_block(dev, match, 9);
203
204                         w1_write_8(dev, W1_CONVERT_TEMP);
205
206                         while (tm) {
207                                 tm = msleep_interruptible(tm);
208                                 if (signal_pending(current))
209                                         flush_signals(current);
210                         }
211
212                         if (!w1_reset_bus (dev)) {
213                                 w1_write_block(dev, match, 9);
214                                 
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);
218                                 }
219
220                                 crc = w1_calc_crc8(rom, 8);
221
222                                 if (rom[8] == crc && rom[0])
223                                         verdict = 1;
224
225                         }
226                 }
227
228                 if (!w1_therm_check_rom(rom))
229                         break;
230         }
231
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");
236         if (verdict)
237                 memcpy(sl->rom, rom, sizeof(sl->rom));
238         else
239                 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
240
241         for (i = 0; i < 9; ++i)
242                 count += sprintf(buf + count, "%02x ", sl->rom[i]);
243         
244         count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom, sl->family->fid));
245 out:
246         up(&dev->mutex);
247 out_dec:
248         smp_mb__before_atomic_inc();
249         atomic_dec(&sl->refcnt);
250
251         return count;
252 }
253
254 static int __init w1_therm_init(void)
255 {
256         int err, i;
257
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);
260                 if (err)
261                         w1_therm_families[i].broken = 1;
262         }
263
264         return 0;
265 }
266
267 static void __exit w1_therm_fini(void)
268 {
269         int i;
270
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);
274 }
275
276 module_init(w1_therm_init);
277 module_exit(w1_therm_fini);