Commit | Line | Data |
---|---|---|
cf978ab2 DB |
1 | /* ------------------------------------------------------------------------- |
2 | * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters | |
3 | * ------------------------------------------------------------------------- | |
4 | * Copyright (C) 1995-2000 Simon G. Vogl | |
1da177e4 LT |
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 | |
5694f8a8 JD |
18 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
19 | MA 02110-1301 USA. | |
cf978ab2 | 20 | * ------------------------------------------------------------------------- */ |
1da177e4 | 21 | |
96de0e25 | 22 | /* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki |
1da177e4 LT |
23 | <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */ |
24 | ||
25 | #include <linux/kernel.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/delay.h> | |
1da177e4 LT |
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 ----------------------------------------------- */ | |
1da177e4 | 36 | |
494dbb64 JD |
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 */ | |
1da177e4 LT |
47 | |
48 | /* ----- global variables --------------------------------------------- */ | |
49 | ||
1da177e4 | 50 | static int bit_test; /* see if the line-setting functions work */ |
1bddab7f JD |
51 | module_param(bit_test, int, S_IRUGO); |
52 | MODULE_PARM_DESC(bit_test, "lines testing - 0 off; 1 report; 2 fail if stuck"); | |
494dbb64 JD |
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 | |
1da177e4 LT |
60 | |
61 | /* --- setting states on the bus with the right timing: --------------- */ | |
62 | ||
cf978ab2 DB |
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) | |
1da177e4 LT |
67 | |
68 | static inline void sdalo(struct i2c_algo_bit_data *adap) | |
69 | { | |
cf978ab2 | 70 | setsda(adap, 0); |
424ed67c | 71 | udelay((adap->udelay + 1) / 2); |
1da177e4 LT |
72 | } |
73 | ||
74 | static inline void sdahi(struct i2c_algo_bit_data *adap) | |
75 | { | |
cf978ab2 | 76 | setsda(adap, 1); |
424ed67c | 77 | udelay((adap->udelay + 1) / 2); |
1da177e4 LT |
78 | } |
79 | ||
80 | static inline void scllo(struct i2c_algo_bit_data *adap) | |
81 | { | |
cf978ab2 | 82 | setscl(adap, 0); |
424ed67c | 83 | udelay(adap->udelay / 2); |
1da177e4 LT |
84 | } |
85 | ||
86 | /* | |
87 | * Raise scl line, and do checking for delays. This is necessary for slower | |
88 | * devices. | |
89 | */ | |
7b288a01 | 90 | static int sclhi(struct i2c_algo_bit_data *adap) |
1da177e4 LT |
91 | { |
92 | unsigned long start; | |
93 | ||
cf978ab2 | 94 | setscl(adap, 1); |
1da177e4 LT |
95 | |
96 | /* Not all adapters have scl sense line... */ | |
7b288a01 JD |
97 | if (!adap->getscl) |
98 | goto done; | |
1da177e4 | 99 | |
cf978ab2 DB |
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 | */ | |
8ee161ce VS |
107 | if (time_after(jiffies, start + adap->timeout)) { |
108 | /* Test one last time, as we may have been preempted | |
109 | * between last check and timeout test. | |
110 | */ | |
111 | if (getscl(adap)) | |
112 | break; | |
1da177e4 | 113 | return -ETIMEDOUT; |
8ee161ce | 114 | } |
41101a33 | 115 | cpu_relax(); |
1da177e4 | 116 | } |
494dbb64 JD |
117 | #ifdef DEBUG |
118 | if (jiffies != start && i2c_debug >= 3) | |
119 | pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " | |
120 | "high\n", jiffies - start); | |
121 | #endif | |
7b288a01 JD |
122 | |
123 | done: | |
1da177e4 LT |
124 | udelay(adap->udelay); |
125 | return 0; | |
cf978ab2 | 126 | } |
1da177e4 LT |
127 | |
128 | ||
129 | /* --- other auxiliary functions -------------------------------------- */ | |
cf978ab2 | 130 | static void i2c_start(struct i2c_algo_bit_data *adap) |
1da177e4 LT |
131 | { |
132 | /* assert: scl, sda are high */ | |
424ed67c JD |
133 | setsda(adap, 0); |
134 | udelay(adap->udelay); | |
1da177e4 LT |
135 | scllo(adap); |
136 | } | |
137 | ||
cf978ab2 | 138 | static void i2c_repstart(struct i2c_algo_bit_data *adap) |
1da177e4 | 139 | { |
424ed67c | 140 | /* assert: scl is low */ |
424ed67c | 141 | sdahi(adap); |
1da177e4 | 142 | sclhi(adap); |
424ed67c JD |
143 | setsda(adap, 0); |
144 | udelay(adap->udelay); | |
1da177e4 LT |
145 | scllo(adap); |
146 | } | |
147 | ||
148 | ||
cf978ab2 | 149 | static void i2c_stop(struct i2c_algo_bit_data *adap) |
1da177e4 | 150 | { |
1da177e4 LT |
151 | /* assert: scl is low */ |
152 | sdalo(adap); | |
cf978ab2 | 153 | sclhi(adap); |
424ed67c JD |
154 | setsda(adap, 1); |
155 | udelay(adap->udelay); | |
1da177e4 LT |
156 | } |
157 | ||
158 | ||
159 | ||
cf978ab2 | 160 | /* send a byte without start cond., look for arbitration, |
1da177e4 LT |
161 | check ackn. from slave */ |
162 | /* returns: | |
163 | * 1 if the device acknowledged | |
164 | * 0 if the device did not ack | |
165 | * -ETIMEDOUT if an error occurred (while raising the scl line) | |
166 | */ | |
494dbb64 | 167 | static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c) |
1da177e4 LT |
168 | { |
169 | int i; | |
170 | int sb; | |
171 | int ack; | |
172 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; | |
173 | ||
174 | /* assert: scl is low */ | |
cf978ab2 | 175 | for (i = 7; i >= 0; i--) { |
494dbb64 | 176 | sb = (c >> i) & 1; |
cf978ab2 | 177 | setsda(adap, sb); |
424ed67c | 178 | udelay((adap->udelay + 1) / 2); |
cf978ab2 | 179 | if (sclhi(adap) < 0) { /* timed out */ |
494dbb64 JD |
180 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
181 | "timeout at bit #%d\n", (int)c, i); | |
1da177e4 | 182 | return -ETIMEDOUT; |
cf978ab2 DB |
183 | } |
184 | /* FIXME do arbitration here: | |
185 | * if (sb && !getsda(adap)) -> ouch! Get out of here. | |
186 | * | |
187 | * Report a unique code, so higher level code can retry | |
188 | * the whole (combined) message and *NOT* issue STOP. | |
1da177e4 | 189 | */ |
424ed67c | 190 | scllo(adap); |
1da177e4 LT |
191 | } |
192 | sdahi(adap); | |
cf978ab2 | 193 | if (sclhi(adap) < 0) { /* timeout */ |
494dbb64 JD |
194 | bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
195 | "timeout at ack\n", (int)c); | |
196 | return -ETIMEDOUT; | |
cf978ab2 DB |
197 | } |
198 | ||
199 | /* read ack: SDA should be pulled down by slave, or it may | |
200 | * NAK (usually to report problems with the data we wrote). | |
201 | */ | |
494dbb64 JD |
202 | ack = !getsda(adap); /* ack: sda is pulled low -> success */ |
203 | bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, | |
204 | ack ? "A" : "NA"); | |
1da177e4 | 205 | |
1da177e4 | 206 | scllo(adap); |
494dbb64 | 207 | return ack; |
1da177e4 LT |
208 | /* assert: scl is low (sda undef) */ |
209 | } | |
210 | ||
211 | ||
cf978ab2 | 212 | static int i2c_inb(struct i2c_adapter *i2c_adap) |
1da177e4 LT |
213 | { |
214 | /* read byte via i2c port, without start/stop sequence */ | |
215 | /* acknowledge is sent in i2c_read. */ | |
216 | int i; | |
cf978ab2 | 217 | unsigned char indata = 0; |
1da177e4 LT |
218 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
219 | ||
220 | /* assert: scl is low */ | |
221 | sdahi(adap); | |
cf978ab2 DB |
222 | for (i = 0; i < 8; i++) { |
223 | if (sclhi(adap) < 0) { /* timeout */ | |
494dbb64 JD |
224 | bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " |
225 | "#%d\n", 7 - i); | |
1da177e4 | 226 | return -ETIMEDOUT; |
cf978ab2 | 227 | } |
1da177e4 | 228 | indata *= 2; |
cf978ab2 | 229 | if (getsda(adap)) |
1da177e4 | 230 | indata |= 0x01; |
424ed67c JD |
231 | setscl(adap, 0); |
232 | udelay(i == 7 ? adap->udelay / 2 : adap->udelay); | |
1da177e4 LT |
233 | } |
234 | /* assert: scl is low */ | |
494dbb64 | 235 | return indata; |
1da177e4 LT |
236 | } |
237 | ||
238 | /* | |
239 | * Sanity check for the adapter hardware - check the reaction of | |
240 | * the bus lines only if it seems to be idle. | |
241 | */ | |
d3b3e15d | 242 | static int test_bus(struct i2c_adapter *i2c_adap) |
cf978ab2 | 243 | { |
d3b3e15d AD |
244 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
245 | const char *name = i2c_adap->name; | |
246 | int scl, sda, ret; | |
247 | ||
248 | if (adap->pre_xfer) { | |
249 | ret = adap->pre_xfer(i2c_adap); | |
250 | if (ret < 0) | |
251 | return -ENODEV; | |
252 | } | |
1da177e4 | 253 | |
cf978ab2 | 254 | if (adap->getscl == NULL) |
494dbb64 | 255 | pr_info("%s: Testing SDA only, SCL is not readable\n", name); |
1da177e4 | 256 | |
cf978ab2 DB |
257 | sda = getsda(adap); |
258 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); | |
259 | if (!scl || !sda) { | |
f6beb67d JD |
260 | printk(KERN_WARNING |
261 | "%s: bus seems to be busy (scl=%d, sda=%d)\n", | |
262 | name, scl, sda); | |
1da177e4 LT |
263 | goto bailout; |
264 | } | |
265 | ||
266 | sdalo(adap); | |
cf978ab2 DB |
267 | sda = getsda(adap); |
268 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); | |
269 | if (sda) { | |
494dbb64 | 270 | printk(KERN_WARNING "%s: SDA stuck high!\n", name); |
1da177e4 LT |
271 | goto bailout; |
272 | } | |
cf978ab2 | 273 | if (!scl) { |
494dbb64 JD |
274 | printk(KERN_WARNING "%s: SCL unexpected low " |
275 | "while pulling SDA low!\n", name); | |
1da177e4 | 276 | goto bailout; |
cf978ab2 | 277 | } |
1da177e4 LT |
278 | |
279 | sdahi(adap); | |
cf978ab2 DB |
280 | sda = getsda(adap); |
281 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); | |
282 | if (!sda) { | |
494dbb64 | 283 | printk(KERN_WARNING "%s: SDA stuck low!\n", name); |
1da177e4 LT |
284 | goto bailout; |
285 | } | |
cf978ab2 | 286 | if (!scl) { |
494dbb64 JD |
287 | printk(KERN_WARNING "%s: SCL unexpected low " |
288 | "while pulling SDA high!\n", name); | |
1da177e4 LT |
289 | goto bailout; |
290 | } | |
291 | ||
292 | scllo(adap); | |
cf978ab2 DB |
293 | sda = getsda(adap); |
294 | scl = (adap->getscl == NULL) ? 0 : getscl(adap); | |
295 | if (scl) { | |
494dbb64 | 296 | printk(KERN_WARNING "%s: SCL stuck high!\n", name); |
1da177e4 LT |
297 | goto bailout; |
298 | } | |
cf978ab2 | 299 | if (!sda) { |
494dbb64 JD |
300 | printk(KERN_WARNING "%s: SDA unexpected low " |
301 | "while pulling SCL low!\n", name); | |
1da177e4 LT |
302 | goto bailout; |
303 | } | |
cf978ab2 | 304 | |
1da177e4 | 305 | sclhi(adap); |
cf978ab2 DB |
306 | sda = getsda(adap); |
307 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); | |
308 | if (!scl) { | |
494dbb64 | 309 | printk(KERN_WARNING "%s: SCL stuck low!\n", name); |
1da177e4 LT |
310 | goto bailout; |
311 | } | |
cf978ab2 | 312 | if (!sda) { |
494dbb64 JD |
313 | printk(KERN_WARNING "%s: SDA unexpected low " |
314 | "while pulling SCL high!\n", name); | |
1da177e4 LT |
315 | goto bailout; |
316 | } | |
d3b3e15d AD |
317 | |
318 | if (adap->post_xfer) | |
319 | adap->post_xfer(i2c_adap); | |
320 | ||
494dbb64 | 321 | pr_info("%s: Test OK\n", name); |
1da177e4 LT |
322 | return 0; |
323 | bailout: | |
324 | sdahi(adap); | |
325 | sclhi(adap); | |
d3b3e15d AD |
326 | |
327 | if (adap->post_xfer) | |
328 | adap->post_xfer(i2c_adap); | |
329 | ||
1da177e4 LT |
330 | return -ENODEV; |
331 | } | |
332 | ||
333 | /* ----- Utility functions | |
334 | */ | |
335 | ||
336 | /* try_address tries to contact a chip for a number of | |
337 | * times before it gives up. | |
338 | * return values: | |
339 | * 1 chip answered | |
340 | * 0 chip did not answer | |
341 | * -x transmission error | |
342 | */ | |
7b288a01 | 343 | static int try_address(struct i2c_adapter *i2c_adap, |
1da177e4 LT |
344 | unsigned char addr, int retries) |
345 | { | |
346 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; | |
97140342 | 347 | int i, ret = 0; |
cf978ab2 DB |
348 | |
349 | for (i = 0; i <= retries; i++) { | |
350 | ret = i2c_outb(i2c_adap, addr); | |
1ecac07a JD |
351 | if (ret == 1 || i == retries) |
352 | break; | |
494dbb64 | 353 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
1da177e4 | 354 | i2c_stop(adap); |
1da177e4 | 355 | udelay(adap->udelay); |
424ed67c | 356 | yield(); |
494dbb64 | 357 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
424ed67c | 358 | i2c_start(adap); |
1da177e4 | 359 | } |
494dbb64 JD |
360 | if (i && ret) |
361 | bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " | |
362 | "0x%02x: %s\n", i + 1, | |
363 | addr & 1 ? "read from" : "write to", addr >> 1, | |
364 | ret == 1 ? "success" : "failed, timeout?"); | |
1da177e4 LT |
365 | return ret; |
366 | } | |
367 | ||
368 | static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) | |
369 | { | |
494dbb64 | 370 | const unsigned char *temp = msg->buf; |
1da177e4 | 371 | int count = msg->len; |
cf978ab2 | 372 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
1da177e4 | 373 | int retval; |
cf978ab2 | 374 | int wrcount = 0; |
1da177e4 LT |
375 | |
376 | while (count > 0) { | |
494dbb64 | 377 | retval = i2c_outb(i2c_adap, *temp); |
cf978ab2 DB |
378 | |
379 | /* OK/ACK; or ignored NAK */ | |
380 | if ((retval > 0) || (nak_ok && (retval == 0))) { | |
381 | count--; | |
1da177e4 LT |
382 | temp++; |
383 | wrcount++; | |
bf3e2d1d DB |
384 | |
385 | /* A slave NAKing the master means the slave didn't like | |
386 | * something about the data it saw. For example, maybe | |
387 | * the SMBus PEC was wrong. | |
388 | */ | |
389 | } else if (retval == 0) { | |
390 | dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); | |
391 | return -EIO; | |
392 | ||
393 | /* Timeout; or (someday) lost arbitration | |
394 | * | |
395 | * FIXME Lost ARB implies retrying the transaction from | |
396 | * the first message, after the "winning" master issues | |
397 | * its STOP. As a rule, upper layer code has no reason | |
398 | * to know or care about this ... it is *NOT* an error. | |
399 | */ | |
400 | } else { | |
401 | dev_err(&i2c_adap->dev, "sendbytes: error %d\n", | |
402 | retval); | |
403 | return retval; | |
1da177e4 | 404 | } |
1da177e4 LT |
405 | } |
406 | return wrcount; | |
407 | } | |
408 | ||
939bc494 DB |
409 | static int acknak(struct i2c_adapter *i2c_adap, int is_ack) |
410 | { | |
411 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; | |
412 | ||
413 | /* assert: sda is high */ | |
414 | if (is_ack) /* send ack */ | |
415 | setsda(adap, 0); | |
416 | udelay((adap->udelay + 1) / 2); | |
417 | if (sclhi(adap) < 0) { /* timeout */ | |
418 | dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); | |
419 | return -ETIMEDOUT; | |
420 | } | |
421 | scllo(adap); | |
422 | return 0; | |
423 | } | |
424 | ||
7b288a01 | 425 | static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
1da177e4 LT |
426 | { |
427 | int inval; | |
cf978ab2 | 428 | int rdcount = 0; /* counts bytes read */ |
494dbb64 | 429 | unsigned char *temp = msg->buf; |
1da177e4 | 430 | int count = msg->len; |
939bc494 | 431 | const unsigned flags = msg->flags; |
1da177e4 LT |
432 | |
433 | while (count > 0) { | |
434 | inval = i2c_inb(i2c_adap); | |
cf978ab2 | 435 | if (inval >= 0) { |
1da177e4 LT |
436 | *temp = inval; |
437 | rdcount++; | |
438 | } else { /* read timed out */ | |
1da177e4 LT |
439 | break; |
440 | } | |
441 | ||
442 | temp++; | |
443 | count--; | |
444 | ||
3c4bb241 JD |
445 | /* Some SMBus transactions require that we receive the |
446 | transaction length as the first read byte. */ | |
939bc494 | 447 | if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { |
3c4bb241 | 448 | if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { |
939bc494 DB |
449 | if (!(flags & I2C_M_NO_RD_ACK)) |
450 | acknak(i2c_adap, 0); | |
494dbb64 JD |
451 | dev_err(&i2c_adap->dev, "readbytes: invalid " |
452 | "block length (%d)\n", inval); | |
abc01b27 | 453 | return -EPROTO; |
3c4bb241 JD |
454 | } |
455 | /* The original count value accounts for the extra | |
456 | bytes, that is, either 1 for a regular transaction, | |
457 | or 2 for a PEC transaction. */ | |
458 | count += inval; | |
459 | msg->len += inval; | |
460 | } | |
939bc494 DB |
461 | |
462 | bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", | |
463 | inval, | |
464 | (flags & I2C_M_NO_RD_ACK) | |
465 | ? "(no ack/nak)" | |
466 | : (count ? "A" : "NA")); | |
467 | ||
468 | if (!(flags & I2C_M_NO_RD_ACK)) { | |
469 | inval = acknak(i2c_adap, count); | |
470 | if (inval < 0) | |
471 | return inval; | |
472 | } | |
1da177e4 LT |
473 | } |
474 | return rdcount; | |
475 | } | |
476 | ||
477 | /* doAddress initiates the transfer by generating the start condition (in | |
478 | * try_address) and transmits the address in the necessary format to handle | |
479 | * reads, writes as well as 10bit-addresses. | |
480 | * returns: | |
481 | * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set | |
abc01b27 | 482 | * -x an error occurred (like: -ENXIO if the device did not answer, or |
cf978ab2 | 483 | * -ETIMEDOUT, for example if the lines are stuck...) |
1da177e4 | 484 | */ |
7b288a01 | 485 | static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
1da177e4 LT |
486 | { |
487 | unsigned short flags = msg->flags; | |
488 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; | |
489 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; | |
490 | ||
491 | unsigned char addr; | |
492 | int ret, retries; | |
493 | ||
494 | retries = nak_ok ? 0 : i2c_adap->retries; | |
cf978ab2 DB |
495 | |
496 | if (flags & I2C_M_TEN) { | |
1da177e4 | 497 | /* a ten bit address */ |
cc6bcf7d | 498 | addr = 0xf0 | ((msg->addr >> 7) & 0x06); |
494dbb64 | 499 | bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); |
1da177e4 LT |
500 | /* try extended address code...*/ |
501 | ret = try_address(i2c_adap, addr, retries); | |
502 | if ((ret != 1) && !nak_ok) { | |
494dbb64 JD |
503 | dev_err(&i2c_adap->dev, |
504 | "died at extended address code\n"); | |
abc01b27 | 505 | return -ENXIO; |
1da177e4 LT |
506 | } |
507 | /* the remaining 8 bit address */ | |
cc6bcf7d | 508 | ret = i2c_outb(i2c_adap, msg->addr & 0xff); |
1da177e4 LT |
509 | if ((ret != 1) && !nak_ok) { |
510 | /* the chip did not ack / xmission error occurred */ | |
494dbb64 | 511 | dev_err(&i2c_adap->dev, "died at 2nd address code\n"); |
abc01b27 | 512 | return -ENXIO; |
1da177e4 | 513 | } |
cf978ab2 | 514 | if (flags & I2C_M_RD) { |
494dbb64 JD |
515 | bit_dbg(3, &i2c_adap->dev, "emitting repeated " |
516 | "start condition\n"); | |
1da177e4 LT |
517 | i2c_repstart(adap); |
518 | /* okay, now switch into reading mode */ | |
519 | addr |= 0x01; | |
520 | ret = try_address(i2c_adap, addr, retries); | |
cf978ab2 | 521 | if ((ret != 1) && !nak_ok) { |
494dbb64 JD |
522 | dev_err(&i2c_adap->dev, |
523 | "died at repeated address code\n"); | |
abc01b27 | 524 | return -EIO; |
1da177e4 LT |
525 | } |
526 | } | |
527 | } else { /* normal 7bit address */ | |
cf978ab2 DB |
528 | addr = msg->addr << 1; |
529 | if (flags & I2C_M_RD) | |
1da177e4 | 530 | addr |= 1; |
cf978ab2 | 531 | if (flags & I2C_M_REV_DIR_ADDR) |
1da177e4 LT |
532 | addr ^= 1; |
533 | ret = try_address(i2c_adap, addr, retries); | |
cf978ab2 | 534 | if ((ret != 1) && !nak_ok) |
97140342 | 535 | return -ENXIO; |
1da177e4 LT |
536 | } |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
541 | static int bit_xfer(struct i2c_adapter *i2c_adap, | |
542 | struct i2c_msg msgs[], int num) | |
543 | { | |
544 | struct i2c_msg *pmsg; | |
545 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; | |
cf978ab2 | 546 | int i, ret; |
1da177e4 LT |
547 | unsigned short nak_ok; |
548 | ||
0a9c1475 JD |
549 | if (adap->pre_xfer) { |
550 | ret = adap->pre_xfer(i2c_adap); | |
551 | if (ret < 0) | |
552 | return ret; | |
553 | } | |
554 | ||
494dbb64 | 555 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
1da177e4 | 556 | i2c_start(adap); |
cf978ab2 | 557 | for (i = 0; i < num; i++) { |
1da177e4 | 558 | pmsg = &msgs[i]; |
cf978ab2 | 559 | nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; |
1da177e4 LT |
560 | if (!(pmsg->flags & I2C_M_NOSTART)) { |
561 | if (i) { | |
494dbb64 JD |
562 | bit_dbg(3, &i2c_adap->dev, "emitting " |
563 | "repeated start condition\n"); | |
1da177e4 LT |
564 | i2c_repstart(adap); |
565 | } | |
566 | ret = bit_doAddress(i2c_adap, pmsg); | |
567 | if ((ret != 0) && !nak_ok) { | |
494dbb64 JD |
568 | bit_dbg(1, &i2c_adap->dev, "NAK from " |
569 | "device addr 0x%02x msg #%d\n", | |
570 | msgs[i].addr, i); | |
1ecac07a | 571 | goto bailout; |
1da177e4 LT |
572 | } |
573 | } | |
cf978ab2 | 574 | if (pmsg->flags & I2C_M_RD) { |
1da177e4 LT |
575 | /* read bytes into buffer*/ |
576 | ret = readbytes(i2c_adap, pmsg); | |
494dbb64 JD |
577 | if (ret >= 1) |
578 | bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", | |
579 | ret, ret == 1 ? "" : "s"); | |
1ecac07a JD |
580 | if (ret < pmsg->len) { |
581 | if (ret >= 0) | |
abc01b27 | 582 | ret = -EIO; |
1ecac07a | 583 | goto bailout; |
1da177e4 LT |
584 | } |
585 | } else { | |
586 | /* write bytes from buffer */ | |
587 | ret = sendbytes(i2c_adap, pmsg); | |
494dbb64 JD |
588 | if (ret >= 1) |
589 | bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", | |
590 | ret, ret == 1 ? "" : "s"); | |
1ecac07a JD |
591 | if (ret < pmsg->len) { |
592 | if (ret >= 0) | |
abc01b27 | 593 | ret = -EIO; |
1ecac07a | 594 | goto bailout; |
1da177e4 LT |
595 | } |
596 | } | |
597 | } | |
1ecac07a JD |
598 | ret = i; |
599 | ||
600 | bailout: | |
494dbb64 | 601 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
1da177e4 | 602 | i2c_stop(adap); |
0a9c1475 JD |
603 | |
604 | if (adap->post_xfer) | |
605 | adap->post_xfer(i2c_adap); | |
1ecac07a | 606 | return ret; |
1da177e4 LT |
607 | } |
608 | ||
609 | static u32 bit_func(struct i2c_adapter *adap) | |
610 | { | |
cf978ab2 | 611 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
3c4bb241 JD |
612 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
613 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | | |
1da177e4 LT |
614 | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; |
615 | } | |
616 | ||
617 | ||
618 | /* -----exported algorithm data: ------------------------------------- */ | |
619 | ||
b0209b39 | 620 | const struct i2c_algorithm i2c_bit_algo = { |
1da177e4 LT |
621 | .master_xfer = bit_xfer, |
622 | .functionality = bit_func, | |
623 | }; | |
b0209b39 | 624 | EXPORT_SYMBOL(i2c_bit_algo); |
1da177e4 | 625 | |
cf978ab2 DB |
626 | /* |
627 | * registering functions to load algorithms at runtime | |
1da177e4 | 628 | */ |
f451171c JD |
629 | static int __i2c_bit_add_bus(struct i2c_adapter *adap, |
630 | int (*add_adapter)(struct i2c_adapter *)) | |
1da177e4 LT |
631 | { |
632 | struct i2c_algo_bit_data *bit_adap = adap->algo_data; | |
af5a60ba | 633 | int ret; |
1da177e4 LT |
634 | |
635 | if (bit_test) { | |
d3b3e15d | 636 | ret = test_bus(adap); |
1bddab7f | 637 | if (bit_test >= 2 && ret < 0) |
1da177e4 LT |
638 | return -ENODEV; |
639 | } | |
640 | ||
1da177e4 | 641 | /* register new adapter to i2c module... */ |
1da177e4 | 642 | adap->algo = &i2c_bit_algo; |
8fcfef6e | 643 | adap->retries = 3; |
1da177e4 | 644 | |
af5a60ba JD |
645 | ret = add_adapter(adap); |
646 | if (ret < 0) | |
647 | return ret; | |
648 | ||
649 | /* Complain if SCL can't be read */ | |
650 | if (bit_adap->getscl == NULL) { | |
651 | dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n"); | |
652 | dev_warn(&adap->dev, "Bus may be unreliable\n"); | |
653 | } | |
654 | return 0; | |
0f3b4838 JD |
655 | } |
656 | ||
657 | int i2c_bit_add_bus(struct i2c_adapter *adap) | |
658 | { | |
f451171c | 659 | return __i2c_bit_add_bus(adap, i2c_add_adapter); |
1da177e4 | 660 | } |
1da177e4 | 661 | EXPORT_SYMBOL(i2c_bit_add_bus); |
1da177e4 | 662 | |
0f3b4838 JD |
663 | int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) |
664 | { | |
f451171c | 665 | return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter); |
0f3b4838 JD |
666 | } |
667 | EXPORT_SYMBOL(i2c_bit_add_numbered_bus); | |
668 | ||
1da177e4 LT |
669 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
670 | MODULE_DESCRIPTION("I2C-Bus bit-banging algorithm"); | |
671 | MODULE_LICENSE("GPL"); |