David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 1 | /* ------------------------------------------------------------------------- |
| 2 | * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters |
| 3 | * ------------------------------------------------------------------------- |
| 4 | * Copyright (C) 1995-2000 Simon G. Vogl |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 19 | * ------------------------------------------------------------------------- */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
Jan Engelhardt | 96de0e2 | 2007-10-19 23:21:04 +0200 | [diff] [blame] | 21 | /* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */ |
| 23 | |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/delay.h> |
| 27 | #include <linux/slab.h> |
| 28 | #include <linux/init.h> |
| 29 | #include <linux/errno.h> |
| 30 | #include <linux/sched.h> |
| 31 | #include <linux/i2c.h> |
| 32 | #include <linux/i2c-algo-bit.h> |
| 33 | |
| 34 | |
| 35 | /* ----- global defines ----------------------------------------------- */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 37 | #ifdef DEBUG |
| 38 | #define bit_dbg(level, dev, format, args...) \ |
| 39 | do { \ |
| 40 | if (i2c_debug >= level) \ |
| 41 | dev_dbg(dev, format, ##args); \ |
| 42 | } while (0) |
| 43 | #else |
| 44 | #define bit_dbg(level, dev, format, args...) \ |
| 45 | do {} while (0) |
| 46 | #endif /* DEBUG */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | |
| 48 | /* ----- global variables --------------------------------------------- */ |
| 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | static int bit_test; /* see if the line-setting functions work */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 51 | module_param(bit_test, bool, 0); |
| 52 | MODULE_PARM_DESC(bit_test, "Test the lines of the bus to see if it is stuck"); |
| 53 | |
| 54 | #ifdef DEBUG |
| 55 | static int i2c_debug = 1; |
| 56 | module_param(i2c_debug, int, S_IRUGO | S_IWUSR); |
| 57 | MODULE_PARM_DESC(i2c_debug, |
| 58 | "debug level - 0 off; 1 normal; 2 verbose; 3 very verbose"); |
| 59 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
| 61 | /* --- setting states on the bus with the right timing: --------------- */ |
| 62 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 63 | #define setsda(adap, val) adap->setsda(adap->data, val) |
| 64 | #define setscl(adap, val) adap->setscl(adap->data, val) |
| 65 | #define getsda(adap) adap->getsda(adap->data) |
| 66 | #define getscl(adap) adap->getscl(adap->data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
| 68 | static inline void sdalo(struct i2c_algo_bit_data *adap) |
| 69 | { |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 70 | setsda(adap, 0); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 71 | udelay((adap->udelay + 1) / 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | } |
| 73 | |
| 74 | static inline void sdahi(struct i2c_algo_bit_data *adap) |
| 75 | { |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 76 | setsda(adap, 1); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 77 | udelay((adap->udelay + 1) / 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | } |
| 79 | |
| 80 | static inline void scllo(struct i2c_algo_bit_data *adap) |
| 81 | { |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 82 | setscl(adap, 0); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 83 | udelay(adap->udelay / 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | } |
| 85 | |
| 86 | /* |
| 87 | * Raise scl line, and do checking for delays. This is necessary for slower |
| 88 | * devices. |
| 89 | */ |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 90 | static int sclhi(struct i2c_algo_bit_data *adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | { |
| 92 | unsigned long start; |
| 93 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 94 | setscl(adap, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | |
| 96 | /* Not all adapters have scl sense line... */ |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 97 | if (!adap->getscl) |
| 98 | goto done; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 100 | start = jiffies; |
| 101 | while (!getscl(adap)) { |
| 102 | /* This hw knows how to read the clock line, so we wait |
| 103 | * until it actually gets high. This is safer as some |
| 104 | * chips may hold it low ("clock stretching") while they |
| 105 | * are processing data internally. |
| 106 | */ |
| 107 | if (time_after_eq(jiffies, start + adap->timeout)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | return -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | cond_resched(); |
| 110 | } |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 111 | #ifdef DEBUG |
| 112 | if (jiffies != start && i2c_debug >= 3) |
| 113 | pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " |
| 114 | "high\n", jiffies - start); |
| 115 | #endif |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 116 | |
| 117 | done: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | udelay(adap->udelay); |
| 119 | return 0; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 120 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | |
| 122 | |
| 123 | /* --- other auxiliary functions -------------------------------------- */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 124 | static void i2c_start(struct i2c_algo_bit_data *adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | { |
| 126 | /* assert: scl, sda are high */ |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 127 | setsda(adap, 0); |
| 128 | udelay(adap->udelay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | scllo(adap); |
| 130 | } |
| 131 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 132 | static void i2c_repstart(struct i2c_algo_bit_data *adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | { |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 134 | /* assert: scl is low */ |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 135 | sdahi(adap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | sclhi(adap); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 137 | setsda(adap, 0); |
| 138 | udelay(adap->udelay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | scllo(adap); |
| 140 | } |
| 141 | |
| 142 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 143 | static void i2c_stop(struct i2c_algo_bit_data *adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | /* assert: scl is low */ |
| 146 | sdalo(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 147 | sclhi(adap); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 148 | setsda(adap, 1); |
| 149 | udelay(adap->udelay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | } |
| 151 | |
| 152 | |
| 153 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 154 | /* send a byte without start cond., look for arbitration, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | check ackn. from slave */ |
| 156 | /* returns: |
| 157 | * 1 if the device acknowledged |
| 158 | * 0 if the device did not ack |
| 159 | * -ETIMEDOUT if an error occurred (while raising the scl line) |
| 160 | */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 161 | static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 162 | { |
| 163 | int i; |
| 164 | int sb; |
| 165 | int ack; |
| 166 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
| 167 | |
| 168 | /* assert: scl is low */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 169 | for (i = 7; i >= 0; i--) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 170 | sb = (c >> i) & 1; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 171 | setsda(adap, sb); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 172 | udelay((adap->udelay + 1) / 2); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 173 | if (sclhi(adap) < 0) { /* timed out */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 174 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
| 175 | "timeout at bit #%d\n", (int)c, i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | return -ETIMEDOUT; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 177 | } |
| 178 | /* FIXME do arbitration here: |
| 179 | * if (sb && !getsda(adap)) -> ouch! Get out of here. |
| 180 | * |
| 181 | * Report a unique code, so higher level code can retry |
| 182 | * the whole (combined) message and *NOT* issue STOP. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | */ |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 184 | scllo(adap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 185 | } |
| 186 | sdahi(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 187 | if (sclhi(adap) < 0) { /* timeout */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 188 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
| 189 | "timeout at ack\n", (int)c); |
| 190 | return -ETIMEDOUT; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 191 | } |
| 192 | |
| 193 | /* read ack: SDA should be pulled down by slave, or it may |
| 194 | * NAK (usually to report problems with the data we wrote). |
| 195 | */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 196 | ack = !getsda(adap); /* ack: sda is pulled low -> success */ |
| 197 | bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, |
| 198 | ack ? "A" : "NA"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | scllo(adap); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 201 | return ack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | /* assert: scl is low (sda undef) */ |
| 203 | } |
| 204 | |
| 205 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 206 | static int i2c_inb(struct i2c_adapter *i2c_adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | { |
| 208 | /* read byte via i2c port, without start/stop sequence */ |
| 209 | /* acknowledge is sent in i2c_read. */ |
| 210 | int i; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 211 | unsigned char indata = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
| 213 | |
| 214 | /* assert: scl is low */ |
| 215 | sdahi(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 216 | for (i = 0; i < 8; i++) { |
| 217 | if (sclhi(adap) < 0) { /* timeout */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 218 | bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " |
| 219 | "#%d\n", 7 - i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | return -ETIMEDOUT; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 221 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | indata *= 2; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 223 | if (getsda(adap)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 224 | indata |= 0x01; |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 225 | setscl(adap, 0); |
| 226 | udelay(i == 7 ? adap->udelay / 2 : adap->udelay); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | } |
| 228 | /* assert: scl is low */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 229 | return indata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | } |
| 231 | |
| 232 | /* |
| 233 | * Sanity check for the adapter hardware - check the reaction of |
| 234 | * the bus lines only if it seems to be idle. |
| 235 | */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 236 | static int test_bus(struct i2c_algo_bit_data *adap, char *name) |
| 237 | { |
| 238 | int scl, sda; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 240 | if (adap->getscl == NULL) |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 241 | pr_info("%s: Testing SDA only, SCL is not readable\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 243 | sda = getsda(adap); |
| 244 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
| 245 | if (!scl || !sda) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 246 | printk(KERN_WARNING "%s: bus seems to be busy\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | goto bailout; |
| 248 | } |
| 249 | |
| 250 | sdalo(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 251 | sda = getsda(adap); |
| 252 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
| 253 | if (sda) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 254 | printk(KERN_WARNING "%s: SDA stuck high!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | goto bailout; |
| 256 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 257 | if (!scl) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 258 | printk(KERN_WARNING "%s: SCL unexpected low " |
| 259 | "while pulling SDA low!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | goto bailout; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 261 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | |
| 263 | sdahi(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 264 | sda = getsda(adap); |
| 265 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
| 266 | if (!sda) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 267 | printk(KERN_WARNING "%s: SDA stuck low!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | goto bailout; |
| 269 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 270 | if (!scl) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 271 | printk(KERN_WARNING "%s: SCL unexpected low " |
| 272 | "while pulling SDA high!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | goto bailout; |
| 274 | } |
| 275 | |
| 276 | scllo(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 277 | sda = getsda(adap); |
| 278 | scl = (adap->getscl == NULL) ? 0 : getscl(adap); |
| 279 | if (scl) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 280 | printk(KERN_WARNING "%s: SCL stuck high!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | goto bailout; |
| 282 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 283 | if (!sda) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 284 | printk(KERN_WARNING "%s: SDA unexpected low " |
| 285 | "while pulling SCL low!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 286 | goto bailout; |
| 287 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 288 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | sclhi(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 290 | sda = getsda(adap); |
| 291 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
| 292 | if (!scl) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 293 | printk(KERN_WARNING "%s: SCL stuck low!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | goto bailout; |
| 295 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 296 | if (!sda) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 297 | printk(KERN_WARNING "%s: SDA unexpected low " |
| 298 | "while pulling SCL high!\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | goto bailout; |
| 300 | } |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 301 | pr_info("%s: Test OK\n", name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 302 | return 0; |
| 303 | bailout: |
| 304 | sdahi(adap); |
| 305 | sclhi(adap); |
| 306 | return -ENODEV; |
| 307 | } |
| 308 | |
| 309 | /* ----- Utility functions |
| 310 | */ |
| 311 | |
| 312 | /* try_address tries to contact a chip for a number of |
| 313 | * times before it gives up. |
| 314 | * return values: |
| 315 | * 1 chip answered |
| 316 | * 0 chip did not answer |
| 317 | * -x transmission error |
| 318 | */ |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 319 | static int try_address(struct i2c_adapter *i2c_adap, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | unsigned char addr, int retries) |
| 321 | { |
| 322 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 323 | int i, ret = -1; |
| 324 | |
| 325 | for (i = 0; i <= retries; i++) { |
| 326 | ret = i2c_outb(i2c_adap, addr); |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 327 | if (ret == 1 || i == retries) |
| 328 | break; |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 329 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 330 | i2c_stop(adap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | udelay(adap->udelay); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 332 | yield(); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 333 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
Jean Delvare | 424ed67 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 334 | i2c_start(adap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | } |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 336 | if (i && ret) |
| 337 | bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " |
| 338 | "0x%02x: %s\n", i + 1, |
| 339 | addr & 1 ? "read from" : "write to", addr >> 1, |
| 340 | ret == 1 ? "success" : "failed, timeout?"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | return ret; |
| 342 | } |
| 343 | |
| 344 | static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
| 345 | { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 346 | const unsigned char *temp = msg->buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | int count = msg->len; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 348 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 349 | int retval; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 350 | int wrcount = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | |
| 352 | while (count > 0) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 353 | retval = i2c_outb(i2c_adap, *temp); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 354 | |
| 355 | /* OK/ACK; or ignored NAK */ |
| 356 | if ((retval > 0) || (nak_ok && (retval == 0))) { |
| 357 | count--; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 358 | temp++; |
| 359 | wrcount++; |
David Brownell | bf3e2d1 | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 360 | |
| 361 | /* A slave NAKing the master means the slave didn't like |
| 362 | * something about the data it saw. For example, maybe |
| 363 | * the SMBus PEC was wrong. |
| 364 | */ |
| 365 | } else if (retval == 0) { |
| 366 | dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); |
| 367 | return -EIO; |
| 368 | |
| 369 | /* Timeout; or (someday) lost arbitration |
| 370 | * |
| 371 | * FIXME Lost ARB implies retrying the transaction from |
| 372 | * the first message, after the "winning" master issues |
| 373 | * its STOP. As a rule, upper layer code has no reason |
| 374 | * to know or care about this ... it is *NOT* an error. |
| 375 | */ |
| 376 | } else { |
| 377 | dev_err(&i2c_adap->dev, "sendbytes: error %d\n", |
| 378 | retval); |
| 379 | return retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 380 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | } |
| 382 | return wrcount; |
| 383 | } |
| 384 | |
David Brownell | 939bc49 | 2007-09-09 22:29:14 +0200 | [diff] [blame] | 385 | static int acknak(struct i2c_adapter *i2c_adap, int is_ack) |
| 386 | { |
| 387 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
| 388 | |
| 389 | /* assert: sda is high */ |
| 390 | if (is_ack) /* send ack */ |
| 391 | setsda(adap, 0); |
| 392 | udelay((adap->udelay + 1) / 2); |
| 393 | if (sclhi(adap) < 0) { /* timeout */ |
| 394 | dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); |
| 395 | return -ETIMEDOUT; |
| 396 | } |
| 397 | scllo(adap); |
| 398 | return 0; |
| 399 | } |
| 400 | |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 401 | static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | { |
| 403 | int inval; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 404 | int rdcount = 0; /* counts bytes read */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 405 | unsigned char *temp = msg->buf; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | int count = msg->len; |
David Brownell | 939bc49 | 2007-09-09 22:29:14 +0200 | [diff] [blame] | 407 | const unsigned flags = msg->flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | |
| 409 | while (count > 0) { |
| 410 | inval = i2c_inb(i2c_adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 411 | if (inval >= 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | *temp = inval; |
| 413 | rdcount++; |
| 414 | } else { /* read timed out */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | break; |
| 416 | } |
| 417 | |
| 418 | temp++; |
| 419 | count--; |
| 420 | |
Jean Delvare | 3c4bb24 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 421 | /* Some SMBus transactions require that we receive the |
| 422 | transaction length as the first read byte. */ |
David Brownell | 939bc49 | 2007-09-09 22:29:14 +0200 | [diff] [blame] | 423 | if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { |
Jean Delvare | 3c4bb24 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 424 | if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { |
David Brownell | 939bc49 | 2007-09-09 22:29:14 +0200 | [diff] [blame] | 425 | if (!(flags & I2C_M_NO_RD_ACK)) |
| 426 | acknak(i2c_adap, 0); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 427 | dev_err(&i2c_adap->dev, "readbytes: invalid " |
| 428 | "block length (%d)\n", inval); |
Jean Delvare | 3c4bb24 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 429 | return -EREMOTEIO; |
| 430 | } |
| 431 | /* The original count value accounts for the extra |
| 432 | bytes, that is, either 1 for a regular transaction, |
| 433 | or 2 for a PEC transaction. */ |
| 434 | count += inval; |
| 435 | msg->len += inval; |
| 436 | } |
David Brownell | 939bc49 | 2007-09-09 22:29:14 +0200 | [diff] [blame] | 437 | |
| 438 | bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", |
| 439 | inval, |
| 440 | (flags & I2C_M_NO_RD_ACK) |
| 441 | ? "(no ack/nak)" |
| 442 | : (count ? "A" : "NA")); |
| 443 | |
| 444 | if (!(flags & I2C_M_NO_RD_ACK)) { |
| 445 | inval = acknak(i2c_adap, count); |
| 446 | if (inval < 0) |
| 447 | return inval; |
| 448 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | } |
| 450 | return rdcount; |
| 451 | } |
| 452 | |
| 453 | /* doAddress initiates the transfer by generating the start condition (in |
| 454 | * try_address) and transmits the address in the necessary format to handle |
| 455 | * reads, writes as well as 10bit-addresses. |
| 456 | * returns: |
| 457 | * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set |
| 458 | * -x an error occurred (like: -EREMOTEIO if the device did not answer, or |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 459 | * -ETIMEDOUT, for example if the lines are stuck...) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | */ |
Jean Delvare | 7b288a0 | 2006-09-03 22:22:12 +0200 | [diff] [blame] | 461 | static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | { |
| 463 | unsigned short flags = msg->flags; |
| 464 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
| 465 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
| 466 | |
| 467 | unsigned char addr; |
| 468 | int ret, retries; |
| 469 | |
| 470 | retries = nak_ok ? 0 : i2c_adap->retries; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 471 | |
| 472 | if (flags & I2C_M_TEN) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | /* a ten bit address */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 474 | addr = 0xf0 | ((msg->addr >> 7) & 0x03); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 475 | bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 476 | /* try extended address code...*/ |
| 477 | ret = try_address(i2c_adap, addr, retries); |
| 478 | if ((ret != 1) && !nak_ok) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 479 | dev_err(&i2c_adap->dev, |
| 480 | "died at extended address code\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | return -EREMOTEIO; |
| 482 | } |
| 483 | /* the remaining 8 bit address */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 484 | ret = i2c_outb(i2c_adap, msg->addr & 0x7f); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | if ((ret != 1) && !nak_ok) { |
| 486 | /* the chip did not ack / xmission error occurred */ |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 487 | dev_err(&i2c_adap->dev, "died at 2nd address code\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | return -EREMOTEIO; |
| 489 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 490 | if (flags & I2C_M_RD) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 491 | bit_dbg(3, &i2c_adap->dev, "emitting repeated " |
| 492 | "start condition\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | i2c_repstart(adap); |
| 494 | /* okay, now switch into reading mode */ |
| 495 | addr |= 0x01; |
| 496 | ret = try_address(i2c_adap, addr, retries); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 497 | if ((ret != 1) && !nak_ok) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 498 | dev_err(&i2c_adap->dev, |
| 499 | "died at repeated address code\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 500 | return -EREMOTEIO; |
| 501 | } |
| 502 | } |
| 503 | } else { /* normal 7bit address */ |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 504 | addr = msg->addr << 1; |
| 505 | if (flags & I2C_M_RD) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | addr |= 1; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 507 | if (flags & I2C_M_REV_DIR_ADDR) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | addr ^= 1; |
| 509 | ret = try_address(i2c_adap, addr, retries); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 510 | if ((ret != 1) && !nak_ok) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | return -EREMOTEIO; |
| 512 | } |
| 513 | |
| 514 | return 0; |
| 515 | } |
| 516 | |
| 517 | static int bit_xfer(struct i2c_adapter *i2c_adap, |
| 518 | struct i2c_msg msgs[], int num) |
| 519 | { |
| 520 | struct i2c_msg *pmsg; |
| 521 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 522 | int i, ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | unsigned short nak_ok; |
| 524 | |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 525 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 526 | i2c_start(adap); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 527 | for (i = 0; i < num; i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 528 | pmsg = &msgs[i]; |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 529 | nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | if (!(pmsg->flags & I2C_M_NOSTART)) { |
| 531 | if (i) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 532 | bit_dbg(3, &i2c_adap->dev, "emitting " |
| 533 | "repeated start condition\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | i2c_repstart(adap); |
| 535 | } |
| 536 | ret = bit_doAddress(i2c_adap, pmsg); |
| 537 | if ((ret != 0) && !nak_ok) { |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 538 | bit_dbg(1, &i2c_adap->dev, "NAK from " |
| 539 | "device addr 0x%02x msg #%d\n", |
| 540 | msgs[i].addr, i); |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 541 | goto bailout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 542 | } |
| 543 | } |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 544 | if (pmsg->flags & I2C_M_RD) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | /* read bytes into buffer*/ |
| 546 | ret = readbytes(i2c_adap, pmsg); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 547 | if (ret >= 1) |
| 548 | bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", |
| 549 | ret, ret == 1 ? "" : "s"); |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 550 | if (ret < pmsg->len) { |
| 551 | if (ret >= 0) |
| 552 | ret = -EREMOTEIO; |
| 553 | goto bailout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | } |
| 555 | } else { |
| 556 | /* write bytes from buffer */ |
| 557 | ret = sendbytes(i2c_adap, pmsg); |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 558 | if (ret >= 1) |
| 559 | bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", |
| 560 | ret, ret == 1 ? "" : "s"); |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 561 | if (ret < pmsg->len) { |
| 562 | if (ret >= 0) |
| 563 | ret = -EREMOTEIO; |
| 564 | goto bailout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | } |
| 566 | } |
| 567 | } |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 568 | ret = i; |
| 569 | |
| 570 | bailout: |
Jean Delvare | 494dbb6 | 2007-05-01 23:26:33 +0200 | [diff] [blame] | 571 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 572 | i2c_stop(adap); |
Jean Delvare | 1ecac07 | 2007-05-01 23:26:28 +0200 | [diff] [blame] | 573 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | } |
| 575 | |
| 576 | static u32 bit_func(struct i2c_adapter *adap) |
| 577 | { |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 578 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
Jean Delvare | 3c4bb24 | 2007-05-01 23:26:29 +0200 | [diff] [blame] | 579 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
| 580 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 581 | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; |
| 582 | } |
| 583 | |
| 584 | |
| 585 | /* -----exported algorithm data: ------------------------------------- */ |
| 586 | |
Jean Delvare | 9e11a9f | 2006-09-03 22:38:52 +0200 | [diff] [blame] | 587 | static const struct i2c_algorithm i2c_bit_algo = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | .master_xfer = bit_xfer, |
| 589 | .functionality = bit_func, |
| 590 | }; |
| 591 | |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 592 | /* |
| 593 | * registering functions to load algorithms at runtime |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | */ |
Jean Delvare | 0f3b483 | 2007-05-01 23:26:31 +0200 | [diff] [blame] | 595 | static int i2c_bit_prepare_bus(struct i2c_adapter *adap) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 596 | { |
| 597 | struct i2c_algo_bit_data *bit_adap = adap->algo_data; |
| 598 | |
| 599 | if (bit_test) { |
| 600 | int ret = test_bus(bit_adap, adap->name); |
David Brownell | cf978ab | 2008-01-27 18:14:46 +0100 | [diff] [blame] | 601 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | return -ENODEV; |
| 603 | } |
| 604 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | /* register new adapter to i2c module... */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 606 | adap->algo = &i2c_bit_algo; |
| 607 | |
| 608 | adap->timeout = 100; /* default values, should */ |
| 609 | adap->retries = 3; /* be replaced by defines */ |
| 610 | |
Jean Delvare | 0f3b483 | 2007-05-01 23:26:31 +0200 | [diff] [blame] | 611 | return 0; |
| 612 | } |
| 613 | |
| 614 | int i2c_bit_add_bus(struct i2c_adapter *adap) |
| 615 | { |
| 616 | int err; |
| 617 | |
| 618 | err = i2c_bit_prepare_bus(adap); |
| 619 | if (err) |
| 620 | return err; |
| 621 | |
Mark M. Hoffman | b39ad0c | 2006-07-01 17:16:06 +0200 | [diff] [blame] | 622 | return i2c_add_adapter(adap); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 623 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 624 | EXPORT_SYMBOL(i2c_bit_add_bus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 625 | |
Jean Delvare | 0f3b483 | 2007-05-01 23:26:31 +0200 | [diff] [blame] | 626 | int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) |
| 627 | { |
| 628 | int err; |
| 629 | |
| 630 | err = i2c_bit_prepare_bus(adap); |
| 631 | if (err) |
| 632 | return err; |
| 633 | |
| 634 | return i2c_add_numbered_adapter(adap); |
| 635 | } |
| 636 | EXPORT_SYMBOL(i2c_bit_add_numbered_bus); |
| 637 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 638 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
| 639 | MODULE_DESCRIPTION("I2C-Bus bit-banging algorithm"); |
| 640 | MODULE_LICENSE("GPL"); |