Commit | Line | Data |
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1da177e4 | 1 | /* |
7785925d | 2 | * w1_io.c |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> | |
7785925d | 5 | * |
1da177e4 LT |
6 | * |
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. | |
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/io.h> | |
23 | ||
24 | #include <linux/delay.h> | |
25 | #include <linux/moduleparam.h> | |
26 | ||
27 | #include "w1.h" | |
28 | #include "w1_log.h" | |
29 | #include "w1_io.h" | |
30 | ||
31 | int w1_delay_parm = 1; | |
32 | module_param_named(delay_coef, w1_delay_parm, int, 0); | |
33 | ||
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 | |
51 | }; | |
52 | ||
53 | void w1_delay(unsigned long tm) | |
54 | { | |
55 | udelay(tm * w1_delay_parm); | |
56 | } | |
57 | ||
58 | u8 w1_touch_bit(struct w1_master *dev, int bit) | |
59 | { | |
60 | if (dev->bus_master->touch_bit) | |
61 | return dev->bus_master->touch_bit(dev->bus_master->data, bit); | |
62 | else | |
63 | return w1_read_bit(dev); | |
64 | } | |
65 | ||
66 | void w1_write_bit(struct w1_master *dev, int bit) | |
67 | { | |
68 | if (bit) { | |
69 | dev->bus_master->write_bit(dev->bus_master->data, 0); | |
70 | w1_delay(6); | |
71 | dev->bus_master->write_bit(dev->bus_master->data, 1); | |
72 | w1_delay(64); | |
73 | } else { | |
74 | dev->bus_master->write_bit(dev->bus_master->data, 0); | |
75 | w1_delay(60); | |
76 | dev->bus_master->write_bit(dev->bus_master->data, 1); | |
77 | w1_delay(10); | |
78 | } | |
79 | } | |
80 | ||
81 | void w1_write_8(struct w1_master *dev, u8 byte) | |
82 | { | |
83 | int i; | |
84 | ||
85 | if (dev->bus_master->write_byte) | |
86 | dev->bus_master->write_byte(dev->bus_master->data, byte); | |
87 | else | |
88 | for (i = 0; i < 8; ++i) | |
89 | w1_write_bit(dev, (byte >> i) & 0x1); | |
90 | } | |
91 | ||
92 | u8 w1_read_bit(struct w1_master *dev) | |
93 | { | |
94 | int result; | |
95 | ||
96 | dev->bus_master->write_bit(dev->bus_master->data, 0); | |
97 | w1_delay(6); | |
98 | dev->bus_master->write_bit(dev->bus_master->data, 1); | |
99 | w1_delay(9); | |
100 | ||
101 | result = dev->bus_master->read_bit(dev->bus_master->data); | |
102 | w1_delay(55); | |
103 | ||
104 | return result & 0x1; | |
105 | } | |
106 | ||
107 | u8 w1_read_8(struct w1_master * dev) | |
108 | { | |
109 | int i; | |
110 | u8 res = 0; | |
111 | ||
112 | if (dev->bus_master->read_byte) | |
113 | res = dev->bus_master->read_byte(dev->bus_master->data); | |
114 | else | |
115 | for (i = 0; i < 8; ++i) | |
116 | res |= (w1_read_bit(dev) << i); | |
117 | ||
118 | return res; | |
119 | } | |
120 | ||
121 | void w1_write_block(struct w1_master *dev, u8 *buf, int len) | |
122 | { | |
123 | int i; | |
124 | ||
125 | if (dev->bus_master->write_block) | |
126 | dev->bus_master->write_block(dev->bus_master->data, buf, len); | |
127 | else | |
128 | for (i = 0; i < len; ++i) | |
129 | w1_write_8(dev, buf[i]); | |
130 | } | |
131 | ||
132 | u8 w1_read_block(struct w1_master *dev, u8 *buf, int len) | |
133 | { | |
134 | int i; | |
135 | u8 ret; | |
136 | ||
137 | if (dev->bus_master->read_block) | |
138 | ret = dev->bus_master->read_block(dev->bus_master->data, buf, len); | |
139 | else { | |
140 | for (i = 0; i < len; ++i) | |
141 | buf[i] = w1_read_8(dev); | |
142 | ret = len; | |
143 | } | |
144 | ||
145 | return ret; | |
146 | } | |
147 | ||
148 | int w1_reset_bus(struct w1_master *dev) | |
149 | { | |
150 | int result = 0; | |
151 | ||
152 | if (dev->bus_master->reset_bus) | |
153 | result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1; | |
154 | else { | |
155 | dev->bus_master->write_bit(dev->bus_master->data, 0); | |
156 | w1_delay(480); | |
157 | dev->bus_master->write_bit(dev->bus_master->data, 1); | |
158 | w1_delay(70); | |
159 | ||
160 | result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1; | |
161 | w1_delay(410); | |
162 | } | |
163 | ||
164 | return result; | |
165 | } | |
166 | ||
167 | u8 w1_calc_crc8(u8 * data, int len) | |
168 | { | |
169 | u8 crc = 0; | |
170 | ||
171 | while (len--) | |
172 | crc = w1_crc8_table[crc ^ *data++]; | |
173 | ||
174 | return crc; | |
175 | } | |
176 | ||
177 | void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb) | |
178 | { | |
179 | dev->attempts++; | |
180 | if (dev->bus_master->search) | |
181 | dev->bus_master->search(dev->bus_master->data, cb); | |
182 | else | |
183 | w1_search(dev); | |
184 | } | |
185 | ||
186 | EXPORT_SYMBOL(w1_write_bit); | |
187 | EXPORT_SYMBOL(w1_write_8); | |
188 | EXPORT_SYMBOL(w1_read_bit); | |
189 | EXPORT_SYMBOL(w1_read_8); | |
190 | EXPORT_SYMBOL(w1_reset_bus); | |
191 | EXPORT_SYMBOL(w1_calc_crc8); | |
192 | EXPORT_SYMBOL(w1_delay); | |
193 | EXPORT_SYMBOL(w1_read_block); | |
194 | EXPORT_SYMBOL(w1_write_block); | |
195 | EXPORT_SYMBOL(w1_search_devices); |