4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms 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.
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.
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
24 #include <linux/delay.h>
25 #include <linux/moduleparam.h>
31 int w1_delay_parm = 1;
32 module_param_named(delay_coef, w1_delay_parm, int, 0);
34 static u8 w1_crc8_table[] = {
35 0, 94, 188, 226, 97, 63, 221, 131, 194, 156, 126, 32, 163, 253, 31, 65,
36 157, 195, 33, 127, 252, 162, 64, 30, 95, 1, 227, 189, 62, 96, 130, 220,
37 35, 125, 159, 193, 66, 28, 254, 160, 225, 191, 93, 3, 128, 222, 60, 98,
38 190, 224, 2, 92, 223, 129, 99, 61, 124, 34, 192, 158, 29, 67, 161, 255,
39 70, 24, 250, 164, 39, 121, 155, 197, 132, 218, 56, 102, 229, 187, 89, 7,
40 219, 133, 103, 57, 186, 228, 6, 88, 25, 71, 165, 251, 120, 38, 196, 154,
41 101, 59, 217, 135, 4, 90, 184, 230, 167, 249, 27, 69, 198, 152, 122, 36,
42 248, 166, 68, 26, 153, 199, 37, 123, 58, 100, 134, 216, 91, 5, 231, 185,
43 140, 210, 48, 110, 237, 179, 81, 15, 78, 16, 242, 172, 47, 113, 147, 205,
44 17, 79, 173, 243, 112, 46, 204, 146, 211, 141, 111, 49, 178, 236, 14, 80,
45 175, 241, 19, 77, 206, 144, 114, 44, 109, 51, 209, 143, 12, 82, 176, 238,
46 50, 108, 142, 208, 83, 13, 239, 177, 240, 174, 76, 18, 145, 207, 45, 115,
47 202, 148, 118, 40, 171, 245, 23, 73, 8, 86, 180, 234, 105, 55, 213, 139,
48 87, 9, 235, 181, 54, 104, 138, 212, 149, 203, 41, 119, 244, 170, 72, 22,
49 233, 183, 85, 11, 136, 214, 52, 106, 43, 117, 151, 201, 74, 20, 246, 168,
50 116, 42, 200, 150, 21, 75, 169, 247, 182, 232, 10, 84, 215, 137, 107, 53
53 void w1_delay(unsigned long tm)
55 udelay(tm * w1_delay_parm);
58 void w1_write_bit(struct w1_master *dev, int bit)
61 dev->bus_master->write_bit(dev->bus_master->data, 0);
63 dev->bus_master->write_bit(dev->bus_master->data, 1);
66 dev->bus_master->write_bit(dev->bus_master->data, 0);
68 dev->bus_master->write_bit(dev->bus_master->data, 1);
73 void w1_write_8(struct w1_master *dev, u8 byte)
77 for (i = 0; i < 8; ++i)
78 w1_write_bit(dev, (byte >> i) & 0x1);
81 u8 w1_read_bit(struct w1_master *dev)
85 dev->bus_master->write_bit(dev->bus_master->data, 0);
87 dev->bus_master->write_bit(dev->bus_master->data, 1);
90 result = dev->bus_master->read_bit(dev->bus_master->data);
96 u8 w1_read_8(struct w1_master * dev)
101 for (i = 0; i < 8; ++i)
102 res |= (w1_read_bit(dev) << i);
107 int w1_reset_bus(struct w1_master *dev)
111 dev->bus_master->write_bit(dev->bus_master->data, 0);
113 dev->bus_master->write_bit(dev->bus_master->data, 1);
116 result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
122 u8 w1_calc_crc8(u8 * data, int len)
127 crc = w1_crc8_table[crc ^ *data++];
132 EXPORT_SYMBOL(w1_write_bit);
133 EXPORT_SYMBOL(w1_write_8);
134 EXPORT_SYMBOL(w1_read_bit);
135 EXPORT_SYMBOL(w1_read_8);
136 EXPORT_SYMBOL(w1_reset_bus);
137 EXPORT_SYMBOL(w1_calc_crc8);
138 EXPORT_SYMBOL(w1_delay);