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Commit | Line | Data |
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1da177e4 | 1 | /* |
7785925d | 2 | * w1_therm.c |
1da177e4 | 3 | * |
a8018766 | 4 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
7785925d | 5 | * |
1da177e4 LT |
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> | |
f6a57033 | 27 | #include <linux/sched.h> |
1da177e4 LT |
28 | #include <linux/device.h> |
29 | #include <linux/types.h> | |
30 | #include <linux/delay.h> | |
31 | ||
bd529cfb | 32 | #include "../w1.h" |
bd529cfb EP |
33 | #include "../w1_int.h" |
34 | #include "../w1_family.h" | |
1da177e4 LT |
35 | |
36 | MODULE_LICENSE("GPL"); | |
a8018766 | 37 | MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>"); |
1da177e4 LT |
38 | MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol, temperature family."); |
39 | ||
6cd15974 DF |
40 | /* Allow the strong pullup to be disabled, but default to enabled. |
41 | * If it was disabled a parasite powered device might not get the require | |
42 | * current to do a temperature conversion. If it is enabled parasite powered | |
43 | * devices have a better chance of getting the current required. | |
44 | */ | |
45 | static int w1_strong_pullup = 1; | |
46 | module_param_named(strong_pullup, w1_strong_pullup, int, 0); | |
47 | ||
1da177e4 | 48 | static u8 bad_roms[][9] = { |
7785925d | 49 | {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87}, |
1da177e4 LT |
50 | {} |
51 | }; | |
52 | ||
347ba8a5 DF |
53 | static ssize_t w1_therm_read(struct device *device, |
54 | struct device_attribute *attr, char *buf); | |
1da177e4 | 55 | |
347ba8a5 DF |
56 | static struct device_attribute w1_therm_attr = |
57 | __ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL); | |
d2a4ef6a EP |
58 | |
59 | static int w1_therm_add_slave(struct w1_slave *sl) | |
60 | { | |
347ba8a5 | 61 | return device_create_file(&sl->dev, &w1_therm_attr); |
d2a4ef6a EP |
62 | } |
63 | ||
64 | static void w1_therm_remove_slave(struct w1_slave *sl) | |
65 | { | |
347ba8a5 | 66 | device_remove_file(&sl->dev, &w1_therm_attr); |
d2a4ef6a EP |
67 | } |
68 | ||
1da177e4 | 69 | static struct w1_family_ops w1_therm_fops = { |
d2a4ef6a EP |
70 | .add_slave = w1_therm_add_slave, |
71 | .remove_slave = w1_therm_remove_slave, | |
1da177e4 LT |
72 | }; |
73 | ||
718a538f EP |
74 | static struct w1_family w1_therm_family_DS18S20 = { |
75 | .fid = W1_THERM_DS18S20, | |
76 | .fops = &w1_therm_fops, | |
77 | }; | |
78 | ||
79 | static struct w1_family w1_therm_family_DS18B20 = { | |
80 | .fid = W1_THERM_DS18B20, | |
81 | .fops = &w1_therm_fops, | |
82 | }; | |
d2a4ef6a | 83 | |
718a538f EP |
84 | static struct w1_family w1_therm_family_DS1822 = { |
85 | .fid = W1_THERM_DS1822, | |
86 | .fops = &w1_therm_fops, | |
87 | }; | |
88 | ||
f7b1371e CG |
89 | static struct w1_family w1_therm_family_DS28EA00 = { |
90 | .fid = W1_THERM_DS28EA00, | |
91 | .fops = &w1_therm_fops, | |
92 | }; | |
93 | ||
718a538f EP |
94 | struct w1_therm_family_converter |
95 | { | |
718a538f EP |
96 | u8 broken; |
97 | u16 reserved; | |
98 | struct w1_family *f; | |
99 | int (*convert)(u8 rom[9]); | |
100 | }; | |
101 | ||
7129b126 | 102 | /* The return value is millidegrees Centigrade. */ |
718a538f EP |
103 | static inline int w1_DS18B20_convert_temp(u8 rom[9]); |
104 | static inline int w1_DS18S20_convert_temp(u8 rom[9]); | |
105 | ||
106 | static struct w1_therm_family_converter w1_therm_families[] = { | |
107 | { | |
718a538f EP |
108 | .f = &w1_therm_family_DS18S20, |
109 | .convert = w1_DS18S20_convert_temp | |
110 | }, | |
111 | { | |
718a538f EP |
112 | .f = &w1_therm_family_DS1822, |
113 | .convert = w1_DS18B20_convert_temp | |
114 | }, | |
115 | { | |
718a538f EP |
116 | .f = &w1_therm_family_DS18B20, |
117 | .convert = w1_DS18B20_convert_temp | |
118 | }, | |
f7b1371e CG |
119 | { |
120 | .f = &w1_therm_family_DS28EA00, | |
121 | .convert = w1_DS18B20_convert_temp | |
122 | }, | |
718a538f EP |
123 | }; |
124 | ||
718a538f EP |
125 | static inline int w1_DS18B20_convert_temp(u8 rom[9]) |
126 | { | |
9a6a1ecd ID |
127 | s16 t = le16_to_cpup((__le16 *)rom); |
128 | return t*1000/16; | |
718a538f EP |
129 | } |
130 | ||
131 | static inline int w1_DS18S20_convert_temp(u8 rom[9]) | |
1da177e4 LT |
132 | { |
133 | int t, h; | |
718a538f EP |
134 | |
135 | if (!rom[7]) | |
136 | return 0; | |
bd529cfb | 137 | |
1da177e4 LT |
138 | if (rom[1] == 0) |
139 | t = ((s32)rom[0] >> 1)*1000; | |
140 | else | |
141 | t = 1000*(-1*(s32)(0x100-rom[0]) >> 1); | |
bd529cfb | 142 | |
1da177e4 LT |
143 | t -= 250; |
144 | h = 1000*((s32)rom[7] - (s32)rom[6]); | |
145 | h /= (s32)rom[7]; | |
146 | t += h; | |
147 | ||
148 | return t; | |
149 | } | |
150 | ||
718a538f EP |
151 | static inline int w1_convert_temp(u8 rom[9], u8 fid) |
152 | { | |
153 | int i; | |
154 | ||
9d0094de | 155 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) |
4e470aa9 | 156 | if (w1_therm_families[i].f->fid == fid) |
718a538f EP |
157 | return w1_therm_families[i].convert(rom); |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
1da177e4 LT |
162 | static int w1_therm_check_rom(u8 rom[9]) |
163 | { | |
164 | int i; | |
165 | ||
166 | for (i=0; i<sizeof(bad_roms)/9; ++i) | |
167 | if (!memcmp(bad_roms[i], rom, 9)) | |
168 | return 1; | |
169 | ||
170 | return 0; | |
171 | } | |
172 | ||
347ba8a5 DF |
173 | static ssize_t w1_therm_read(struct device *device, |
174 | struct device_attribute *attr, char *buf) | |
1da177e4 | 175 | { |
347ba8a5 | 176 | struct w1_slave *sl = dev_to_w1_slave(device); |
1da177e4 LT |
177 | struct w1_master *dev = sl->master; |
178 | u8 rom[9], crc, verdict; | |
179 | int i, max_trying = 10; | |
347ba8a5 | 180 | ssize_t c = PAGE_SIZE; |
1da177e4 | 181 | |
e0d29c76 | 182 | mutex_lock(&dev->mutex); |
1da177e4 | 183 | |
1da177e4 LT |
184 | memset(rom, 0, sizeof(rom)); |
185 | ||
1da177e4 LT |
186 | verdict = 0; |
187 | crc = 0; | |
188 | ||
189 | while (max_trying--) { | |
ea7d8f65 | 190 | if (!w1_reset_select_slave(sl)) { |
1da177e4 | 191 | int count = 0; |
1da177e4 LT |
192 | unsigned int tm = 750; |
193 | ||
6cd15974 DF |
194 | /* 750ms strong pullup (or delay) after the convert */ |
195 | if (w1_strong_pullup) | |
196 | w1_next_pullup(dev, tm); | |
1da177e4 | 197 | w1_write_8(dev, W1_CONVERT_TEMP); |
6cd15974 DF |
198 | if (!w1_strong_pullup) |
199 | msleep(tm); | |
1da177e4 | 200 | |
ea7d8f65 | 201 | if (!w1_reset_select_slave(sl)) { |
7785925d | 202 | |
1da177e4 LT |
203 | w1_write_8(dev, W1_READ_SCRATCHPAD); |
204 | if ((count = w1_read_block(dev, rom, 9)) != 9) { | |
347ba8a5 DF |
205 | dev_warn(device, "w1_read_block() " |
206 | "returned %u instead of 9.\n", | |
207 | count); | |
1da177e4 LT |
208 | } |
209 | ||
210 | crc = w1_calc_crc8(rom, 8); | |
211 | ||
80c002dd | 212 | if (rom[8] == crc) |
1da177e4 | 213 | verdict = 1; |
1da177e4 LT |
214 | } |
215 | } | |
216 | ||
217 | if (!w1_therm_check_rom(rom)) | |
218 | break; | |
219 | } | |
220 | ||
221 | for (i = 0; i < 9; ++i) | |
347ba8a5 DF |
222 | c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]); |
223 | c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", | |
1da177e4 LT |
224 | crc, (verdict) ? "YES" : "NO"); |
225 | if (verdict) | |
226 | memcpy(sl->rom, rom, sizeof(sl->rom)); | |
227 | else | |
347ba8a5 | 228 | dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n"); |
1da177e4 LT |
229 | |
230 | for (i = 0; i < 9; ++i) | |
347ba8a5 | 231 | c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]); |
bd529cfb | 232 | |
347ba8a5 DF |
233 | c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", |
234 | w1_convert_temp(rom, sl->family->fid)); | |
abd52a13 | 235 | mutex_unlock(&dev->mutex); |
1da177e4 | 236 | |
347ba8a5 | 237 | return PAGE_SIZE - c; |
1da177e4 LT |
238 | } |
239 | ||
1da177e4 LT |
240 | static int __init w1_therm_init(void) |
241 | { | |
718a538f EP |
242 | int err, i; |
243 | ||
9d0094de | 244 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { |
718a538f EP |
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; | |
1da177e4 LT |
251 | } |
252 | ||
253 | static void __exit w1_therm_fini(void) | |
254 | { | |
718a538f EP |
255 | int i; |
256 | ||
9d0094de | 257 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) |
718a538f EP |
258 | if (!w1_therm_families[i].broken) |
259 | w1_unregister_family(w1_therm_families[i].f); | |
1da177e4 LT |
260 | } |
261 | ||
262 | module_init(w1_therm_init); | |
263 | module_exit(w1_therm_fini); |