Rev 1125 | Rev 1963 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
1125 | serge | 1 | /* ------------------------------------------------------------------------- |
2 | * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters |
||
3 | * ------------------------------------------------------------------------- |
||
4 | * Copyright (C) 1995-2000 Simon G. Vogl |
||
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 |
||
18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
||
19 | * ------------------------------------------------------------------------- */ |
||
20 | |||
21 | /* With some changes from Frodo Looijaard |
||
22 |
|
||
23 | |||
24 | #include |
||
25 | #include |
||
1403 | serge | 26 | #include |
1125 | serge | 27 | #include |
28 | #include |
||
29 | #include |
||
30 | #include |
||
31 | |||
32 | |||
33 | /* ----- global defines ----------------------------------------------- */ |
||
34 | |||
35 | #ifdef DEBUG |
||
36 | #define bit_dbg(level, dev, format, args...) \ |
||
37 | do { \ |
||
38 | if (i2c_debug >= level) \ |
||
39 | dev_dbg(dev, format, ##args); \ |
||
40 | } while (0) |
||
41 | #else |
||
42 | #define bit_dbg(level, dev, format, args...) \ |
||
43 | do {} while (0) |
||
44 | #endif /* DEBUG */ |
||
45 | |||
46 | |||
47 | /* ----- global variables --------------------------------------------- */ |
||
48 | |||
49 | static int bit_test; /* see if the line-setting functions work */ |
||
50 | |||
51 | |||
52 | /* --- setting states on the bus with the right timing: --------------- */ |
||
53 | |||
54 | #define setsda(adap, val) adap->setsda(adap->data, val) |
||
55 | #define setscl(adap, val) adap->setscl(adap->data, val) |
||
56 | #define getsda(adap) adap->getsda(adap->data) |
||
57 | #define getscl(adap) adap->getscl(adap->data) |
||
58 | |||
59 | static inline void sdalo(struct i2c_algo_bit_data *adap) |
||
60 | { |
||
61 | setsda(adap, 0); |
||
62 | udelay((adap->udelay + 1) / 2); |
||
63 | } |
||
64 | |||
65 | static inline void sdahi(struct i2c_algo_bit_data *adap) |
||
66 | { |
||
67 | setsda(adap, 1); |
||
68 | udelay((adap->udelay + 1) / 2); |
||
69 | } |
||
70 | |||
71 | static inline void scllo(struct i2c_algo_bit_data *adap) |
||
72 | { |
||
73 | setscl(adap, 0); |
||
74 | udelay(adap->udelay / 2); |
||
75 | } |
||
76 | |||
77 | /* |
||
78 | * Raise scl line, and do checking for delays. This is necessary for slower |
||
79 | * devices. |
||
80 | */ |
||
81 | static int sclhi(struct i2c_algo_bit_data *adap) |
||
82 | { |
||
83 | unsigned long start; |
||
84 | |||
85 | setscl(adap, 1); |
||
86 | |||
87 | /* Not all adapters have scl sense line... */ |
||
88 | if (!adap->getscl) |
||
89 | goto done; |
||
90 | |||
91 | // start = jiffies; |
||
92 | while (!getscl(adap)) { |
||
93 | /* This hw knows how to read the clock line, so we wait |
||
94 | * until it actually gets high. This is safer as some |
||
95 | * chips may hold it low ("clock stretching") while they |
||
96 | * are processing data internally. |
||
97 | */ |
||
98 | // if (time_after(jiffies, start + adap->timeout)) |
||
99 | // return -ETIMEDOUT; |
||
100 | |||
101 | udelay(adap->udelay); |
||
102 | |||
103 | // cond_resched(); |
||
104 | } |
||
105 | #ifdef DEBUG |
||
106 | if (jiffies != start && i2c_debug >= 3) |
||
107 | pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " |
||
108 | "high\n", jiffies - start); |
||
109 | #endif |
||
110 | |||
111 | done: |
||
112 | udelay(adap->udelay); |
||
113 | return 0; |
||
114 | } |
||
115 | |||
116 | |||
117 | /* --- other auxiliary functions -------------------------------------- */ |
||
118 | static void i2c_start(struct i2c_algo_bit_data *adap) |
||
119 | { |
||
120 | /* assert: scl, sda are high */ |
||
121 | setsda(adap, 0); |
||
122 | udelay(adap->udelay); |
||
123 | scllo(adap); |
||
124 | } |
||
125 | |||
126 | static void i2c_repstart(struct i2c_algo_bit_data *adap) |
||
127 | { |
||
128 | /* assert: scl is low */ |
||
129 | sdahi(adap); |
||
130 | sclhi(adap); |
||
131 | setsda(adap, 0); |
||
132 | udelay(adap->udelay); |
||
133 | scllo(adap); |
||
134 | } |
||
135 | |||
136 | |||
137 | static void i2c_stop(struct i2c_algo_bit_data *adap) |
||
138 | { |
||
139 | /* assert: scl is low */ |
||
140 | sdalo(adap); |
||
141 | sclhi(adap); |
||
142 | setsda(adap, 1); |
||
143 | udelay(adap->udelay); |
||
144 | } |
||
145 | |||
146 | |||
147 | |||
148 | /* send a byte without start cond., look for arbitration, |
||
149 | check ackn. from slave */ |
||
150 | /* returns: |
||
151 | * 1 if the device acknowledged |
||
152 | * 0 if the device did not ack |
||
153 | * -ETIMEDOUT if an error occurred (while raising the scl line) |
||
154 | */ |
||
155 | static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c) |
||
156 | { |
||
157 | int i; |
||
158 | int sb; |
||
159 | int ack; |
||
160 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
161 | |||
162 | /* assert: scl is low */ |
||
163 | for (i = 7; i >= 0; i--) { |
||
164 | sb = (c >> i) & 1; |
||
165 | setsda(adap, sb); |
||
166 | udelay((adap->udelay + 1) / 2); |
||
167 | if (sclhi(adap) < 0) { /* timed out */ |
||
168 | // bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
||
169 | // "timeout at bit #%d\n", (int)c, i); |
||
170 | return -ETIMEDOUT; |
||
171 | } |
||
172 | /* FIXME do arbitration here: |
||
173 | * if (sb && !getsda(adap)) -> ouch! Get out of here. |
||
174 | * |
||
175 | * Report a unique code, so higher level code can retry |
||
176 | * the whole (combined) message and *NOT* issue STOP. |
||
177 | */ |
||
178 | scllo(adap); |
||
179 | } |
||
180 | sdahi(adap); |
||
181 | if (sclhi(adap) < 0) { /* timeout */ |
||
182 | // bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " |
||
183 | // "timeout at ack\n", (int)c); |
||
184 | return -ETIMEDOUT; |
||
185 | } |
||
186 | |||
187 | /* read ack: SDA should be pulled down by slave, or it may |
||
188 | * NAK (usually to report problems with the data we wrote). |
||
189 | */ |
||
190 | ack = !getsda(adap); /* ack: sda is pulled low -> success */ |
||
191 | // bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, |
||
192 | // ack ? "A" : "NA"); |
||
193 | |||
194 | scllo(adap); |
||
195 | return ack; |
||
196 | /* assert: scl is low (sda undef) */ |
||
197 | } |
||
198 | |||
199 | |||
200 | static int i2c_inb(struct i2c_adapter *i2c_adap) |
||
201 | { |
||
202 | /* read byte via i2c port, without start/stop sequence */ |
||
203 | /* acknowledge is sent in i2c_read. */ |
||
204 | int i; |
||
205 | unsigned char indata = 0; |
||
206 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
207 | |||
208 | /* assert: scl is low */ |
||
209 | sdahi(adap); |
||
210 | for (i = 0; i < 8; i++) { |
||
211 | if (sclhi(adap) < 0) { /* timeout */ |
||
212 | bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " |
||
213 | "#%d\n", 7 - i); |
||
214 | return -ETIMEDOUT; |
||
215 | } |
||
216 | indata *= 2; |
||
217 | if (getsda(adap)) |
||
218 | indata |= 0x01; |
||
219 | setscl(adap, 0); |
||
220 | udelay(i == 7 ? adap->udelay / 2 : adap->udelay); |
||
221 | } |
||
222 | /* assert: scl is low */ |
||
223 | return indata; |
||
224 | } |
||
225 | |||
226 | /* |
||
227 | * Sanity check for the adapter hardware - check the reaction of |
||
228 | * the bus lines only if it seems to be idle. |
||
229 | */ |
||
230 | static int test_bus(struct i2c_algo_bit_data *adap, char *name) |
||
231 | { |
||
232 | int scl, sda; |
||
233 | |||
234 | if (adap->getscl == NULL) |
||
235 | pr_info("%s: Testing SDA only, SCL is not readable\n", name); |
||
236 | |||
237 | sda = getsda(adap); |
||
238 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
||
239 | if (!scl || !sda) { |
||
240 | printk(KERN_WARNING "%s: bus seems to be busy\n", name); |
||
241 | goto bailout; |
||
242 | } |
||
243 | |||
244 | sdalo(adap); |
||
245 | sda = getsda(adap); |
||
246 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
||
247 | if (sda) { |
||
248 | printk(KERN_WARNING "%s: SDA stuck high!\n", name); |
||
249 | goto bailout; |
||
250 | } |
||
251 | if (!scl) { |
||
252 | printk(KERN_WARNING "%s: SCL unexpected low " |
||
253 | "while pulling SDA low!\n", name); |
||
254 | goto bailout; |
||
255 | } |
||
256 | |||
257 | sdahi(adap); |
||
258 | sda = getsda(adap); |
||
259 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
||
260 | if (!sda) { |
||
261 | printk(KERN_WARNING "%s: SDA stuck low!\n", name); |
||
262 | goto bailout; |
||
263 | } |
||
264 | if (!scl) { |
||
265 | printk(KERN_WARNING "%s: SCL unexpected low " |
||
266 | "while pulling SDA high!\n", name); |
||
267 | goto bailout; |
||
268 | } |
||
269 | |||
270 | scllo(adap); |
||
271 | sda = getsda(adap); |
||
272 | scl = (adap->getscl == NULL) ? 0 : getscl(adap); |
||
273 | if (scl) { |
||
274 | printk(KERN_WARNING "%s: SCL stuck high!\n", name); |
||
275 | goto bailout; |
||
276 | } |
||
277 | if (!sda) { |
||
278 | printk(KERN_WARNING "%s: SDA unexpected low " |
||
279 | "while pulling SCL low!\n", name); |
||
280 | goto bailout; |
||
281 | } |
||
282 | |||
283 | sclhi(adap); |
||
284 | sda = getsda(adap); |
||
285 | scl = (adap->getscl == NULL) ? 1 : getscl(adap); |
||
286 | if (!scl) { |
||
287 | printk(KERN_WARNING "%s: SCL stuck low!\n", name); |
||
288 | goto bailout; |
||
289 | } |
||
290 | if (!sda) { |
||
291 | printk(KERN_WARNING "%s: SDA unexpected low " |
||
292 | "while pulling SCL high!\n", name); |
||
293 | goto bailout; |
||
294 | } |
||
295 | pr_info("%s: Test OK\n", name); |
||
296 | return 0; |
||
297 | bailout: |
||
298 | sdahi(adap); |
||
299 | sclhi(adap); |
||
300 | return -ENODEV; |
||
301 | } |
||
302 | |||
303 | /* ----- Utility functions |
||
304 | */ |
||
305 | |||
306 | /* try_address tries to contact a chip for a number of |
||
307 | * times before it gives up. |
||
308 | * return values: |
||
309 | * 1 chip answered |
||
310 | * 0 chip did not answer |
||
311 | * -x transmission error |
||
312 | */ |
||
313 | static int try_address(struct i2c_adapter *i2c_adap, |
||
314 | unsigned char addr, int retries) |
||
315 | { |
||
316 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
317 | int i, ret = 0; |
||
318 | |||
319 | for (i = 0; i <= retries; i++) { |
||
320 | ret = i2c_outb(i2c_adap, addr); |
||
321 | if (ret == 1 || i == retries) |
||
322 | break; |
||
323 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
||
324 | i2c_stop(adap); |
||
325 | udelay(adap->udelay); |
||
326 | // yield(); |
||
327 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
||
328 | i2c_start(adap); |
||
329 | } |
||
330 | if (i && ret) |
||
331 | bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " |
||
332 | "0x%02x: %s\n", i + 1, |
||
333 | addr & 1 ? "read from" : "write to", addr >> 1, |
||
334 | ret == 1 ? "success" : "failed, timeout?"); |
||
335 | return ret; |
||
336 | } |
||
337 | |||
338 | static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
||
339 | { |
||
340 | const unsigned char *temp = msg->buf; |
||
341 | int count = msg->len; |
||
342 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
||
343 | int retval; |
||
344 | int wrcount = 0; |
||
345 | |||
346 | while (count > 0) { |
||
347 | retval = i2c_outb(i2c_adap, *temp); |
||
348 | |||
349 | /* OK/ACK; or ignored NAK */ |
||
350 | if ((retval > 0) || (nak_ok && (retval == 0))) { |
||
351 | count--; |
||
352 | temp++; |
||
353 | wrcount++; |
||
354 | |||
355 | /* A slave NAKing the master means the slave didn't like |
||
356 | * something about the data it saw. For example, maybe |
||
357 | * the SMBus PEC was wrong. |
||
358 | */ |
||
359 | } else if (retval == 0) { |
||
360 | // dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); |
||
361 | return -EIO; |
||
362 | |||
363 | /* Timeout; or (someday) lost arbitration |
||
364 | * |
||
365 | * FIXME Lost ARB implies retrying the transaction from |
||
366 | * the first message, after the "winning" master issues |
||
367 | * its STOP. As a rule, upper layer code has no reason |
||
368 | * to know or care about this ... it is *NOT* an error. |
||
369 | */ |
||
370 | } else { |
||
371 | // dev_err(&i2c_adap->dev, "sendbytes: error %d\n", |
||
372 | // retval); |
||
373 | return retval; |
||
374 | } |
||
375 | } |
||
376 | return wrcount; |
||
377 | } |
||
378 | |||
379 | static int acknak(struct i2c_adapter *i2c_adap, int is_ack) |
||
380 | { |
||
381 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
382 | |||
383 | /* assert: sda is high */ |
||
384 | if (is_ack) /* send ack */ |
||
385 | setsda(adap, 0); |
||
386 | udelay((adap->udelay + 1) / 2); |
||
387 | if (sclhi(adap) < 0) { /* timeout */ |
||
388 | // dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); |
||
389 | // return -ETIMEDOUT; |
||
390 | } |
||
391 | scllo(adap); |
||
392 | return 0; |
||
393 | } |
||
394 | |||
395 | static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
||
396 | { |
||
397 | int inval; |
||
398 | int rdcount = 0; /* counts bytes read */ |
||
399 | unsigned char *temp = msg->buf; |
||
400 | int count = msg->len; |
||
401 | const unsigned flags = msg->flags; |
||
402 | |||
403 | while (count > 0) { |
||
404 | inval = i2c_inb(i2c_adap); |
||
405 | if (inval >= 0) { |
||
406 | *temp = inval; |
||
407 | rdcount++; |
||
408 | } else { /* read timed out */ |
||
409 | break; |
||
410 | } |
||
411 | |||
412 | temp++; |
||
413 | count--; |
||
414 | |||
415 | /* Some SMBus transactions require that we receive the |
||
416 | transaction length as the first read byte. */ |
||
417 | if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { |
||
418 | if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { |
||
419 | if (!(flags & I2C_M_NO_RD_ACK)) |
||
420 | acknak(i2c_adap, 0); |
||
421 | // dev_err(&i2c_adap->dev, "readbytes: invalid " |
||
422 | // "block length (%d)\n", inval); |
||
423 | return -EREMOTEIO; |
||
424 | } |
||
425 | /* The original count value accounts for the extra |
||
426 | bytes, that is, either 1 for a regular transaction, |
||
427 | or 2 for a PEC transaction. */ |
||
428 | count += inval; |
||
429 | msg->len += inval; |
||
430 | } |
||
431 | |||
432 | // bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", |
||
433 | // inval, |
||
434 | // (flags & I2C_M_NO_RD_ACK) |
||
435 | // ? "(no ack/nak)" |
||
436 | // : (count ? "A" : "NA")); |
||
437 | |||
438 | if (!(flags & I2C_M_NO_RD_ACK)) { |
||
439 | inval = acknak(i2c_adap, count); |
||
440 | if (inval < 0) |
||
441 | return inval; |
||
442 | } |
||
443 | } |
||
444 | return rdcount; |
||
445 | } |
||
446 | |||
447 | /* doAddress initiates the transfer by generating the start condition (in |
||
448 | * try_address) and transmits the address in the necessary format to handle |
||
449 | * reads, writes as well as 10bit-addresses. |
||
450 | * returns: |
||
451 | * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set |
||
452 | * -x an error occurred (like: -EREMOTEIO if the device did not answer, or |
||
453 | * -ETIMEDOUT, for example if the lines are stuck...) |
||
454 | */ |
||
455 | static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) |
||
456 | { |
||
457 | unsigned short flags = msg->flags; |
||
458 | unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; |
||
459 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
460 | |||
461 | unsigned char addr; |
||
462 | int ret, retries; |
||
463 | |||
464 | retries = nak_ok ? 0 : i2c_adap->retries; |
||
465 | |||
466 | if (flags & I2C_M_TEN) { |
||
467 | /* a ten bit address */ |
||
468 | addr = 0xf0 | ((msg->addr >> 7) & 0x03); |
||
469 | bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); |
||
470 | /* try extended address code...*/ |
||
471 | ret = try_address(i2c_adap, addr, retries); |
||
472 | if ((ret != 1) && !nak_ok) { |
||
473 | // dev_err(&i2c_adap->dev, |
||
474 | // "died at extended address code\n"); |
||
475 | return -EREMOTEIO; |
||
476 | } |
||
477 | /* the remaining 8 bit address */ |
||
478 | ret = i2c_outb(i2c_adap, msg->addr & 0x7f); |
||
479 | if ((ret != 1) && !nak_ok) { |
||
480 | /* the chip did not ack / xmission error occurred */ |
||
481 | // dev_err(&i2c_adap->dev, "died at 2nd address code\n"); |
||
482 | return -EREMOTEIO; |
||
483 | } |
||
484 | if (flags & I2C_M_RD) { |
||
485 | bit_dbg(3, &i2c_adap->dev, "emitting repeated " |
||
486 | "start condition\n"); |
||
487 | i2c_repstart(adap); |
||
488 | /* okay, now switch into reading mode */ |
||
489 | addr |= 0x01; |
||
490 | ret = try_address(i2c_adap, addr, retries); |
||
491 | if ((ret != 1) && !nak_ok) { |
||
492 | // dev_err(&i2c_adap->dev, |
||
493 | // "died at repeated address code\n"); |
||
494 | return -EREMOTEIO; |
||
495 | } |
||
496 | } |
||
497 | } else { /* normal 7bit address */ |
||
498 | addr = msg->addr << 1; |
||
499 | if (flags & I2C_M_RD) |
||
500 | addr |= 1; |
||
501 | if (flags & I2C_M_REV_DIR_ADDR) |
||
502 | addr ^= 1; |
||
503 | ret = try_address(i2c_adap, addr, retries); |
||
504 | if ((ret != 1) && !nak_ok) |
||
505 | return -ENXIO; |
||
506 | } |
||
507 | |||
508 | return 0; |
||
509 | } |
||
510 | |||
511 | static int bit_xfer(struct i2c_adapter *i2c_adap, |
||
512 | struct i2c_msg msgs[], int num) |
||
513 | { |
||
514 | struct i2c_msg *pmsg; |
||
515 | struct i2c_algo_bit_data *adap = i2c_adap->algo_data; |
||
516 | int i, ret; |
||
517 | unsigned short nak_ok; |
||
518 | |||
519 | bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); |
||
520 | i2c_start(adap); |
||
521 | for (i = 0; i < num; i++) { |
||
522 | pmsg = &msgs[i]; |
||
523 | nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; |
||
524 | if (!(pmsg->flags & I2C_M_NOSTART)) { |
||
525 | if (i) { |
||
526 | bit_dbg(3, &i2c_adap->dev, "emitting " |
||
527 | "repeated start condition\n"); |
||
528 | i2c_repstart(adap); |
||
529 | } |
||
530 | ret = bit_doAddress(i2c_adap, pmsg); |
||
531 | if ((ret != 0) && !nak_ok) { |
||
532 | bit_dbg(1, &i2c_adap->dev, "NAK from " |
||
533 | "device addr 0x%02x msg #%d\n", |
||
534 | msgs[i].addr, i); |
||
535 | goto bailout; |
||
536 | } |
||
537 | } |
||
538 | if (pmsg->flags & I2C_M_RD) { |
||
539 | /* read bytes into buffer*/ |
||
540 | ret = readbytes(i2c_adap, pmsg); |
||
541 | if (ret >= 1) |
||
542 | bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", |
||
543 | ret, ret == 1 ? "" : "s"); |
||
544 | if (ret < pmsg->len) { |
||
545 | if (ret >= 0) |
||
546 | ret = -EREMOTEIO; |
||
547 | goto bailout; |
||
548 | } |
||
549 | } else { |
||
550 | /* write bytes from buffer */ |
||
551 | ret = sendbytes(i2c_adap, pmsg); |
||
552 | if (ret >= 1) |
||
553 | bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", |
||
554 | ret, ret == 1 ? "" : "s"); |
||
555 | if (ret < pmsg->len) { |
||
556 | if (ret >= 0) |
||
557 | ret = -EREMOTEIO; |
||
558 | goto bailout; |
||
559 | } |
||
560 | } |
||
561 | } |
||
562 | ret = i; |
||
563 | |||
564 | bailout: |
||
565 | bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); |
||
566 | i2c_stop(adap); |
||
567 | return ret; |
||
568 | } |
||
569 | |||
570 | static u32 bit_func(struct i2c_adapter *adap) |
||
571 | { |
||
572 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | |
||
573 | I2C_FUNC_SMBUS_READ_BLOCK_DATA | |
||
574 | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | |
||
575 | I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; |
||
576 | } |
||
577 | |||
578 | |||
579 | /* -----exported algorithm data: ------------------------------------- */ |
||
580 | |||
581 | static const struct i2c_algorithm i2c_bit_algo = { |
||
582 | .master_xfer = bit_xfer, |
||
583 | .functionality = bit_func, |
||
584 | }; |
||
585 | |||
586 | /* |
||
587 | * registering functions to load algorithms at runtime |
||
588 | */ |
||
589 | static int i2c_bit_prepare_bus(struct i2c_adapter *adap) |
||
590 | { |
||
591 | struct i2c_algo_bit_data *bit_adap = adap->algo_data; |
||
592 | |||
593 | // if (bit_test) { |
||
594 | // int ret = test_bus(bit_adap, adap->name); |
||
595 | // if (ret < 0) |
||
596 | // return -ENODEV; |
||
597 | // } |
||
598 | |||
599 | /* register new adapter to i2c module... */ |
||
600 | adap->algo = &i2c_bit_algo; |
||
601 | adap->retries = 3; |
||
602 | |||
603 | return 0; |
||
604 | } |
||
605 | |||
606 | int i2c_bit_add_bus(struct i2c_adapter *adap) |
||
607 | { |
||
608 | int err; |
||
609 | |||
610 | err = i2c_bit_prepare_bus(adap); |
||
611 | if (err) |
||
612 | return err; |
||
613 | |||
614 | return 0; //i2c_add_adapter(adap); |
||
615 | }>>>>><>>=>>=>>>>> |
||
616 |