[PATCH] Driver Core: drivers/usb/input/aiptek.c - drivers/zorro/zorro-sysfs.c: update...
[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 ssize_t w1_therm_read_name(struct device *dev, struct device_attribute *attr, char *buf)
57 {
58         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
59
60         return sprintf(buf, "%s\n", sl->name);
61 }
62
63 static inline int w1_convert_temp(u8 rom[9])
64 {
65         int t, h;
66         
67         if (rom[1] == 0)
68                 t = ((s32)rom[0] >> 1)*1000;
69         else
70                 t = 1000*(-1*(s32)(0x100-rom[0]) >> 1);
71         
72         t -= 250;
73         h = 1000*((s32)rom[7] - (s32)rom[6]);
74         h /= (s32)rom[7];
75         t += h;
76
77         return t;
78 }
79
80 static ssize_t w1_therm_read_temp(struct device *dev, struct device_attribute *attr, char *buf)
81 {
82         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
83
84         return sprintf(buf, "%d\n", w1_convert_temp(sl->rom));
85 }
86
87 static int w1_therm_check_rom(u8 rom[9])
88 {
89         int i;
90
91         for (i=0; i<sizeof(bad_roms)/9; ++i)
92                 if (!memcmp(bad_roms[i], rom, 9))
93                         return 1;
94
95         return 0;
96 }
97
98 static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, size_t count)
99 {
100         struct w1_slave *sl = container_of(container_of(kobj, struct device, kobj),
101                                                 struct w1_slave, dev);
102         struct w1_master *dev = sl->master;
103         u8 rom[9], crc, verdict;
104         int i, max_trying = 10;
105
106         atomic_inc(&sl->refcnt);
107         smp_mb__after_atomic_inc();
108         if (down_interruptible(&sl->master->mutex)) {
109                 count = 0;
110                 goto out_dec;
111         }
112
113         if (off > W1_SLAVE_DATA_SIZE) {
114                 count = 0;
115                 goto out;
116         }
117         if (off + count > W1_SLAVE_DATA_SIZE) {
118                 count = 0;
119                 goto out;
120         }
121
122         memset(buf, 0, count);
123         memset(rom, 0, sizeof(rom));
124
125         count = 0;
126         verdict = 0;
127         crc = 0;
128
129         while (max_trying--) {
130                 if (!w1_reset_bus (dev)) {
131                         int count = 0;
132                         u8 match[9] = {W1_MATCH_ROM, };
133                         unsigned int tm = 750;
134
135                         memcpy(&match[1], (u64 *) & sl->reg_num, 8);
136                         
137                         w1_write_block(dev, match, 9);
138
139                         w1_write_8(dev, W1_CONVERT_TEMP);
140
141                         while (tm) {
142                                 tm = msleep_interruptible(tm);
143                                 if (signal_pending(current))
144                                         flush_signals(current);
145                         }
146
147                         if (!w1_reset_bus (dev)) {
148                                 w1_write_block(dev, match, 9);
149                                 
150                                 w1_write_8(dev, W1_READ_SCRATCHPAD);
151                                 if ((count = w1_read_block(dev, rom, 9)) != 9) {
152                                         dev_warn(&dev->dev, "w1_read_block() returned %d instead of 9.\n", count);
153                                 }
154
155                                 crc = w1_calc_crc8(rom, 8);
156
157                                 if (rom[8] == crc && rom[0])
158                                         verdict = 1;
159
160                         }
161                 }
162
163                 if (!w1_therm_check_rom(rom))
164                         break;
165         }
166
167         for (i = 0; i < 9; ++i)
168                 count += sprintf(buf + count, "%02x ", rom[i]);
169         count += sprintf(buf + count, ": crc=%02x %s\n",
170                            crc, (verdict) ? "YES" : "NO");
171         if (verdict)
172                 memcpy(sl->rom, rom, sizeof(sl->rom));
173         else
174                 dev_warn(&dev->dev, "18S20 doesn't respond to CONVERT_TEMP.\n");
175
176         for (i = 0; i < 9; ++i)
177                 count += sprintf(buf + count, "%02x ", sl->rom[i]);
178         
179         count += sprintf(buf + count, "t=%d\n", w1_convert_temp(rom));
180 out:
181         up(&dev->mutex);
182 out_dec:
183         smp_mb__before_atomic_inc();
184         atomic_dec(&sl->refcnt);
185
186         return count;
187 }
188
189 static struct w1_family w1_therm_family = {
190         .fid = W1_FAMILY_THERM,
191         .fops = &w1_therm_fops,
192 };
193
194 static int __init w1_therm_init(void)
195 {
196         return w1_register_family(&w1_therm_family);
197 }
198
199 static void __exit w1_therm_fini(void)
200 {
201         w1_unregister_family(&w1_therm_family);
202 }
203
204 module_init(w1_therm_init);
205 module_exit(w1_therm_fini);