Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 2 | * w1_therm.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 5 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Al Viro | f6a5703 | 2006-10-18 01:47:25 -0400 | [diff] [blame] | 27 | #include <linux/sched.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | #include <linux/device.h> |
| 29 | #include <linux/types.h> |
| 30 | #include <linux/delay.h> |
| 31 | |
Evgeniy Polyakov | bd529cf | 2005-12-06 13:38:28 +0300 | [diff] [blame] | 32 | #include "../w1.h" |
Evgeniy Polyakov | bd529cf | 2005-12-06 13:38:28 +0300 | [diff] [blame] | 33 | #include "../w1_int.h" |
| 34 | #include "../w1_family.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
David Fries | 6cd1597 | 2008-10-15 22:04:43 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | static u8 bad_roms[][9] = { |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 49 | {0xaa, 0x00, 0x4b, 0x46, 0xff, 0xff, 0x0c, 0x10, 0x87}, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | {} |
| 51 | }; |
| 52 | |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 53 | static ssize_t w1_therm_read(struct device *device, |
| 54 | struct device_attribute *attr, char *buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 56 | static struct device_attribute w1_therm_attr = |
| 57 | __ATTR(w1_slave, S_IRUGO, w1_therm_read, NULL); |
Evgeniy Polyakov | d2a4ef6 | 2005-08-11 17:27:50 +0400 | [diff] [blame] | 58 | |
| 59 | static int w1_therm_add_slave(struct w1_slave *sl) |
| 60 | { |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 61 | return device_create_file(&sl->dev, &w1_therm_attr); |
Evgeniy Polyakov | d2a4ef6 | 2005-08-11 17:27:50 +0400 | [diff] [blame] | 62 | } |
| 63 | |
| 64 | static void w1_therm_remove_slave(struct w1_slave *sl) |
| 65 | { |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 66 | device_remove_file(&sl->dev, &w1_therm_attr); |
Evgeniy Polyakov | d2a4ef6 | 2005-08-11 17:27:50 +0400 | [diff] [blame] | 67 | } |
| 68 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | static struct w1_family_ops w1_therm_fops = { |
Evgeniy Polyakov | d2a4ef6 | 2005-08-11 17:27:50 +0400 | [diff] [blame] | 70 | .add_slave = w1_therm_add_slave, |
| 71 | .remove_slave = w1_therm_remove_slave, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | }; |
| 73 | |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 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 | }; |
Evgeniy Polyakov | d2a4ef6 | 2005-08-11 17:27:50 +0400 | [diff] [blame] | 83 | |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 84 | static struct w1_family w1_therm_family_DS1822 = { |
| 85 | .fid = W1_THERM_DS1822, |
| 86 | .fops = &w1_therm_fops, |
| 87 | }; |
| 88 | |
Christian Glindkamp | f7b1371 | 2011-07-26 16:08:55 -0700 | [diff] [blame^] | 89 | static struct w1_family w1_therm_family_DS28EA00 = { |
| 90 | .fid = W1_THERM_DS28EA00, |
| 91 | .fops = &w1_therm_fops, |
| 92 | }; |
| 93 | |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 94 | struct w1_therm_family_converter |
| 95 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 96 | u8 broken; |
| 97 | u16 reserved; |
| 98 | struct w1_family *f; |
| 99 | int (*convert)(u8 rom[9]); |
| 100 | }; |
| 101 | |
David Fries | 7129b12 | 2008-02-06 01:38:09 -0800 | [diff] [blame] | 102 | /* The return value is millidegrees Centigrade. */ |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 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 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 108 | .f = &w1_therm_family_DS18S20, |
| 109 | .convert = w1_DS18S20_convert_temp |
| 110 | }, |
| 111 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 112 | .f = &w1_therm_family_DS1822, |
| 113 | .convert = w1_DS18B20_convert_temp |
| 114 | }, |
| 115 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 116 | .f = &w1_therm_family_DS18B20, |
| 117 | .convert = w1_DS18B20_convert_temp |
| 118 | }, |
Christian Glindkamp | f7b1371 | 2011-07-26 16:08:55 -0700 | [diff] [blame^] | 119 | { |
| 120 | .f = &w1_therm_family_DS28EA00, |
| 121 | .convert = w1_DS18B20_convert_temp |
| 122 | }, |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 123 | }; |
| 124 | |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 125 | static inline int w1_DS18B20_convert_temp(u8 rom[9]) |
| 126 | { |
Ian Dall | 9a6a1ec | 2010-04-23 13:17:53 -0400 | [diff] [blame] | 127 | s16 t = le16_to_cpup((__le16 *)rom); |
| 128 | return t*1000/16; |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 129 | } |
| 130 | |
| 131 | static inline int w1_DS18S20_convert_temp(u8 rom[9]) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | { |
| 133 | int t, h; |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 134 | |
| 135 | if (!rom[7]) |
| 136 | return 0; |
Evgeniy Polyakov | bd529cf | 2005-12-06 13:38:28 +0300 | [diff] [blame] | 137 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | if (rom[1] == 0) |
| 139 | t = ((s32)rom[0] >> 1)*1000; |
| 140 | else |
| 141 | t = 1000*(-1*(s32)(0x100-rom[0]) >> 1); |
Evgeniy Polyakov | bd529cf | 2005-12-06 13:38:28 +0300 | [diff] [blame] | 142 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 151 | static inline int w1_convert_temp(u8 rom[9], u8 fid) |
| 152 | { |
| 153 | int i; |
| 154 | |
Ahmed S. Darwish | 9d0094d | 2007-02-12 00:52:05 -0800 | [diff] [blame] | 155 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) |
Evgeniy Polyakov | 4e470aa | 2005-05-20 22:50:33 +0400 | [diff] [blame] | 156 | if (w1_therm_families[i].f->fid == fid) |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 157 | return w1_therm_families[i].convert(rom); |
| 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 173 | static ssize_t w1_therm_read(struct device *device, |
| 174 | struct device_attribute *attr, char *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | { |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 176 | struct w1_slave *sl = dev_to_w1_slave(device); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | struct w1_master *dev = sl->master; |
| 178 | u8 rom[9], crc, verdict; |
| 179 | int i, max_trying = 10; |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 180 | ssize_t c = PAGE_SIZE; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
David Fries | e0d29c7 | 2008-10-15 22:04:52 -0700 | [diff] [blame] | 182 | mutex_lock(&dev->mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | memset(rom, 0, sizeof(rom)); |
| 185 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | verdict = 0; |
| 187 | crc = 0; |
| 188 | |
| 189 | while (max_trying--) { |
Evgeniy Polyakov | ea7d8f6 | 2005-08-11 17:27:49 +0400 | [diff] [blame] | 190 | if (!w1_reset_select_slave(sl)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | int count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 192 | unsigned int tm = 750; |
| 193 | |
David Fries | 6cd1597 | 2008-10-15 22:04:43 -0700 | [diff] [blame] | 194 | /* 750ms strong pullup (or delay) after the convert */ |
| 195 | if (w1_strong_pullup) |
| 196 | w1_next_pullup(dev, tm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | w1_write_8(dev, W1_CONVERT_TEMP); |
David Fries | 6cd1597 | 2008-10-15 22:04:43 -0700 | [diff] [blame] | 198 | if (!w1_strong_pullup) |
| 199 | msleep(tm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | |
Evgeniy Polyakov | ea7d8f6 | 2005-08-11 17:27:49 +0400 | [diff] [blame] | 201 | if (!w1_reset_select_slave(sl)) { |
Evgeniy Polyakov | 7785925 | 2005-05-20 22:33:25 +0400 | [diff] [blame] | 202 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | w1_write_8(dev, W1_READ_SCRATCHPAD); |
| 204 | if ((count = w1_read_block(dev, rom, 9)) != 9) { |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 205 | dev_warn(device, "w1_read_block() " |
| 206 | "returned %u instead of 9.\n", |
| 207 | count); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | } |
| 209 | |
| 210 | crc = w1_calc_crc8(rom, 8); |
| 211 | |
David Fries | 80c002d | 2008-01-22 03:31:39 -0800 | [diff] [blame] | 212 | if (rom[8] == crc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 213 | verdict = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | } |
| 215 | } |
| 216 | |
| 217 | if (!w1_therm_check_rom(rom)) |
| 218 | break; |
| 219 | } |
| 220 | |
| 221 | for (i = 0; i < 9; ++i) |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 222 | c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", rom[i]); |
| 223 | c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | crc, (verdict) ? "YES" : "NO"); |
| 225 | if (verdict) |
| 226 | memcpy(sl->rom, rom, sizeof(sl->rom)); |
| 227 | else |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 228 | dev_warn(device, "18S20 doesn't respond to CONVERT_TEMP.\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 229 | |
| 230 | for (i = 0; i < 9; ++i) |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 231 | c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]); |
Evgeniy Polyakov | bd529cf | 2005-12-06 13:38:28 +0300 | [diff] [blame] | 232 | |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 233 | c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n", |
| 234 | w1_convert_temp(rom, sl->family->fid)); |
Evgeniy Polyakov | abd52a1 | 2006-04-03 12:04:27 +0400 | [diff] [blame] | 235 | mutex_unlock(&dev->mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | |
David Fries | 347ba8a | 2008-10-15 22:04:51 -0700 | [diff] [blame] | 237 | return PAGE_SIZE - c; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | } |
| 239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | static int __init w1_therm_init(void) |
| 241 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 242 | int err, i; |
| 243 | |
Ahmed S. Darwish | 9d0094d | 2007-02-12 00:52:05 -0800 | [diff] [blame] | 244 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 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; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | } |
| 252 | |
| 253 | static void __exit w1_therm_fini(void) |
| 254 | { |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 255 | int i; |
| 256 | |
Ahmed S. Darwish | 9d0094d | 2007-02-12 00:52:05 -0800 | [diff] [blame] | 257 | for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) |
Evgeniy Polyakov | 718a538 | 2005-04-17 22:58:14 +0400 | [diff] [blame] | 258 | if (!w1_therm_families[i].broken) |
| 259 | w1_unregister_family(w1_therm_families[i].f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | } |
| 261 | |
| 262 | module_init(w1_therm_init); |
| 263 | module_exit(w1_therm_fini); |