Commit | Line | Data |
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1da177e4 LT |
1 | /*!***************************************************************************** |
2 | *! | |
3 | *! Implements an interface for i2c compatible eeproms to run under linux. | |
4 | *! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustents by | |
5 | *! Johan.Adolfsson@axis.com | |
6 | *! | |
7 | *! Probing results: | |
8 | *! 8k or not is detected (the assumes 2k or 16k) | |
9 | *! 2k or 16k detected using test reads and writes. | |
10 | *! | |
11 | *!------------------------------------------------------------------------ | |
12 | *! HISTORY | |
13 | *! | |
14 | *! DATE NAME CHANGES | |
15 | *! ---- ---- ------- | |
16 | *! Aug 28 1999 Edgar Iglesias Initial Version | |
17 | *! Aug 31 1999 Edgar Iglesias Allow simultaneous users. | |
18 | *! Sep 03 1999 Edgar Iglesias Updated probe. | |
19 | *! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted | |
20 | *! in the spin-lock. | |
21 | *! | |
22 | *! $Log: eeprom.c,v $ | |
23 | *! Revision 1.10 2003/09/11 07:29:48 starvik | |
24 | *! Merge of Linux 2.6.0-test5 | |
25 | *! | |
26 | *! Revision 1.9 2003/07/04 08:27:37 starvik | |
27 | *! Merge of Linux 2.5.74 | |
28 | *! | |
29 | *! Revision 1.8 2003/04/09 05:20:47 starvik | |
30 | *! Merge of Linux 2.5.67 | |
31 | *! | |
32 | *! Revision 1.6 2003/02/10 07:19:28 starvik | |
33 | *! Removed misplaced ; | |
34 | *! | |
35 | *! Revision 1.5 2002/12/11 13:13:57 starvik | |
36 | *! Added arch/ to v10 specific includes | |
37 | *! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer) | |
38 | *! | |
39 | *! Revision 1.4 2002/11/20 11:56:10 starvik | |
40 | *! Merge of Linux 2.5.48 | |
41 | *! | |
42 | *! Revision 1.3 2002/11/18 13:16:06 starvik | |
43 | *! Linux 2.5 port of latest 2.4 drivers | |
44 | *! | |
45 | *! Revision 1.8 2001/06/15 13:24:29 jonashg | |
46 | *! * Added verification of pointers from userspace in read and write. | |
47 | *! * Made busy counter volatile. | |
48 | *! * Added define for inital write delay. | |
49 | *! * Removed warnings by using loff_t instead of unsigned long. | |
50 | *! | |
51 | *! Revision 1.7 2001/06/14 15:26:54 jonashg | |
52 | *! Removed test because condition is always true. | |
53 | *! | |
54 | *! Revision 1.6 2001/06/14 15:18:20 jonashg | |
55 | *! Kb -> kB (makes quite a difference if you don't know if you have 2k or 16k). | |
56 | *! | |
57 | *! Revision 1.5 2001/06/14 14:39:51 jonashg | |
58 | *! Forgot to use name when registering the driver. | |
59 | *! | |
60 | *! Revision 1.4 2001/06/14 14:35:47 jonashg | |
61 | *! * Gave driver a name and used it in printk's. | |
62 | *! * Cleanup. | |
63 | *! | |
64 | *! Revision 1.3 2001/03/19 16:04:46 markusl | |
65 | *! Fixed init of fops struct | |
66 | *! | |
67 | *! Revision 1.2 2001/03/19 10:35:07 markusl | |
68 | *! 2.4 port of eeprom driver | |
69 | *! | |
70 | *! Revision 1.8 2000/05/18 10:42:25 edgar | |
71 | *! Make sure to end write cycle on _every_ write | |
72 | *! | |
73 | *! Revision 1.7 2000/01/17 17:41:01 johana | |
74 | *! Adjusted probing and return -ENOSPC when writing outside EEPROM | |
75 | *! | |
76 | *! Revision 1.6 2000/01/17 15:50:36 johana | |
77 | *! Added adaptive timing adjustments and fixed autoprobing for 2k and 16k(?) | |
78 | *! EEPROMs | |
79 | *! | |
80 | *! Revision 1.5 1999/09/03 15:07:37 edgar | |
81 | *! Added bail-out check to the spinlock | |
82 | *! | |
83 | *! Revision 1.4 1999/09/03 12:11:17 bjornw | |
84 | *! Proper atomicity (need to use spinlocks, not if's). users -> busy. | |
85 | *! | |
86 | *! | |
87 | *! (c) 1999 Axis Communications AB, Lund, Sweden | |
88 | *!*****************************************************************************/ | |
89 | ||
90 | #include <linux/config.h> | |
91 | #include <linux/kernel.h> | |
92 | #include <linux/sched.h> | |
93 | #include <linux/fs.h> | |
94 | #include <linux/init.h> | |
95 | #include <linux/delay.h> | |
96 | #include <linux/interrupt.h> | |
97 | #include <asm/uaccess.h> | |
98 | #include "i2c.h" | |
99 | ||
100 | #define D(x) | |
101 | ||
102 | /* If we should use adaptive timing or not: */ | |
103 | //#define EEPROM_ADAPTIVE_TIMING | |
104 | ||
105 | #define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */ | |
106 | #define EEPROM_MINOR_NR 0 | |
107 | ||
108 | /* Empirical sane initial value of the delay, the value will be adapted to | |
109 | * what the chip needs when using EEPROM_ADAPTIVE_TIMING. | |
110 | */ | |
111 | #define INITIAL_WRITEDELAY_US 4000 | |
112 | #define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */ | |
113 | ||
114 | /* This one defines how many times to try when eeprom fails. */ | |
115 | #define EEPROM_RETRIES 10 | |
116 | ||
117 | #define EEPROM_2KB (2 * 1024) | |
118 | /*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */ | |
119 | #define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */ | |
120 | #define EEPROM_16KB (16 * 1024) | |
121 | ||
122 | #define i2c_delay(x) udelay(x) | |
123 | ||
124 | /* | |
125 | * This structure describes the attached eeprom chip. | |
126 | * The values are probed for. | |
127 | */ | |
128 | ||
129 | struct eeprom_type | |
130 | { | |
131 | unsigned long size; | |
132 | unsigned long sequential_write_pagesize; | |
133 | unsigned char select_cmd; | |
134 | unsigned long usec_delay_writecycles; /* Min time between write cycles | |
135 | (up to 10ms for some models) */ | |
136 | unsigned long usec_delay_step; /* For adaptive algorithm */ | |
137 | int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */ | |
138 | ||
139 | /* this one is to keep the read/write operations atomic */ | |
140 | wait_queue_head_t wait_q; | |
141 | volatile int busy; | |
142 | int retry_cnt_addr; /* Used to keep track of number of retries for | |
143 | adaptive timing adjustments */ | |
144 | int retry_cnt_read; | |
145 | }; | |
146 | ||
147 | static int eeprom_open(struct inode * inode, struct file * file); | |
148 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig); | |
149 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, | |
150 | loff_t *off); | |
151 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
152 | loff_t *off); | |
153 | static int eeprom_close(struct inode * inode, struct file * file); | |
154 | ||
155 | static int eeprom_address(unsigned long addr); | |
156 | static int read_from_eeprom(char * buf, int count); | |
157 | static int eeprom_write_buf(loff_t addr, const char * buf, int count); | |
158 | static int eeprom_read_buf(loff_t addr, char * buf, int count); | |
159 | ||
160 | static void eeprom_disable_write_protect(void); | |
161 | ||
162 | ||
163 | static const char eeprom_name[] = "eeprom"; | |
164 | ||
165 | /* chip description */ | |
166 | static struct eeprom_type eeprom; | |
167 | ||
168 | /* This is the exported file-operations structure for this device. */ | |
169 | struct file_operations eeprom_fops = | |
170 | { | |
171 | .llseek = eeprom_lseek, | |
172 | .read = eeprom_read, | |
173 | .write = eeprom_write, | |
174 | .open = eeprom_open, | |
175 | .release = eeprom_close | |
176 | }; | |
177 | ||
178 | /* eeprom init call. Probes for different eeprom models. */ | |
179 | ||
180 | int __init eeprom_init(void) | |
181 | { | |
182 | init_waitqueue_head(&eeprom.wait_q); | |
183 | eeprom.busy = 0; | |
184 | ||
185 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
186 | #define EETEXT "Found" | |
187 | #else | |
188 | #define EETEXT "Assuming" | |
189 | #endif | |
190 | if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops)) | |
191 | { | |
192 | printk(KERN_INFO "%s: unable to get major %d for eeprom device\n", | |
193 | eeprom_name, EEPROM_MAJOR_NR); | |
194 | return -1; | |
195 | } | |
196 | ||
197 | printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n"); | |
198 | ||
199 | /* | |
200 | * Note: Most of this probing method was taken from the printserver (5470e) | |
201 | * codebase. It did not contain a way of finding the 16kB chips | |
202 | * (M24128 or variants). The method used here might not work | |
203 | * for all models. If you encounter problems the easiest way | |
204 | * is probably to define your model within #ifdef's, and hard- | |
205 | * code it. | |
206 | */ | |
207 | ||
208 | eeprom.size = 0; | |
209 | eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US; | |
210 | eeprom.usec_delay_step = 128; | |
211 | eeprom.adapt_state = 0; | |
212 | ||
213 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
214 | i2c_start(); | |
215 | i2c_outbyte(0x80); | |
216 | if(!i2c_getack()) | |
217 | { | |
218 | /* It's not 8k.. */ | |
219 | int success = 0; | |
220 | unsigned char buf_2k_start[16]; | |
221 | ||
222 | /* Im not sure this will work... :) */ | |
223 | /* assume 2kB, if failure go for 16kB */ | |
224 | /* Test with 16kB settings.. */ | |
225 | /* If it's a 2kB EEPROM and we address it outside it's range | |
226 | * it will mirror the address space: | |
227 | * 1. We read two locations (that are mirrored), | |
228 | * if the content differs * it's a 16kB EEPROM. | |
229 | * 2. if it doesn't differ - write different value to one of the locations, | |
230 | * check the other - if content still is the same it's a 2k EEPROM, | |
231 | * restore original data. | |
232 | */ | |
233 | #define LOC1 8 | |
234 | #define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */ | |
235 | ||
236 | /* 2k settings */ | |
237 | i2c_stop(); | |
238 | eeprom.size = EEPROM_2KB; | |
239 | eeprom.select_cmd = 0xA0; | |
240 | eeprom.sequential_write_pagesize = 16; | |
241 | if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 ) | |
242 | { | |
243 | D(printk("2k start: '%16.16s'\n", buf_2k_start)); | |
244 | } | |
245 | else | |
246 | { | |
247 | printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name); | |
248 | } | |
249 | ||
250 | /* 16k settings */ | |
251 | eeprom.size = EEPROM_16KB; | |
252 | eeprom.select_cmd = 0xA0; | |
253 | eeprom.sequential_write_pagesize = 64; | |
254 | ||
255 | { | |
256 | unsigned char loc1[4], loc2[4], tmp[4]; | |
257 | if( eeprom_read_buf(LOC2, loc2, 4) == 4) | |
258 | { | |
259 | if( eeprom_read_buf(LOC1, loc1, 4) == 4) | |
260 | { | |
261 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
262 | LOC1, loc1, LOC2, loc2)); | |
263 | #if 0 | |
264 | if (memcmp(loc1, loc2, 4) != 0 ) | |
265 | { | |
266 | /* It's 16k */ | |
267 | printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name); | |
268 | eeprom.size = EEPROM_16KB; | |
269 | success = 1; | |
270 | } | |
271 | else | |
272 | #endif | |
273 | { | |
274 | /* Do step 2 check */ | |
275 | /* Invert value */ | |
276 | loc1[0] = ~loc1[0]; | |
277 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
278 | { | |
279 | /* If 2k EEPROM this write will actually write 10 bytes | |
280 | * from pos 0 | |
281 | */ | |
282 | D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
283 | LOC1, loc1, LOC2, loc2)); | |
284 | if( eeprom_read_buf(LOC1, tmp, 4) == 4) | |
285 | { | |
286 | D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n", | |
287 | LOC1, loc1, tmp)); | |
288 | if (memcmp(loc1, tmp, 4) != 0 ) | |
289 | { | |
290 | printk(KERN_INFO "%s: read and write differs! Not 16kB\n", | |
291 | eeprom_name); | |
292 | loc1[0] = ~loc1[0]; | |
293 | ||
294 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
295 | { | |
296 | success = 1; | |
297 | } | |
298 | else | |
299 | { | |
300 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
301 | " EEPROM might be corrupt!\n", eeprom_name); | |
302 | ||
303 | } | |
304 | i2c_stop(); | |
305 | /* Go to 2k mode and write original data */ | |
306 | eeprom.size = EEPROM_2KB; | |
307 | eeprom.select_cmd = 0xA0; | |
308 | eeprom.sequential_write_pagesize = 16; | |
309 | if( eeprom_write_buf(0, buf_2k_start, 16) == 16) | |
310 | { | |
311 | } | |
312 | else | |
313 | { | |
314 | printk(KERN_INFO "%s: Failed to write back 2k start!\n", | |
315 | eeprom_name); | |
316 | } | |
317 | ||
318 | eeprom.size = EEPROM_2KB; | |
319 | } | |
320 | } | |
321 | ||
322 | if(!success) | |
323 | { | |
324 | if( eeprom_read_buf(LOC2, loc2, 1) == 1) | |
325 | { | |
326 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
327 | LOC1, loc1, LOC2, loc2)); | |
328 | if (memcmp(loc1, loc2, 4) == 0 ) | |
329 | { | |
330 | /* Data the same, must be mirrored -> 2k */ | |
331 | /* Restore data */ | |
332 | printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name); | |
333 | loc1[0] = ~loc1[0]; | |
334 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
335 | { | |
336 | success = 1; | |
337 | } | |
338 | else | |
339 | { | |
340 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
341 | " EEPROM might be corrupt!\n", eeprom_name); | |
342 | ||
343 | } | |
344 | ||
345 | eeprom.size = EEPROM_2KB; | |
346 | } | |
347 | else | |
348 | { | |
349 | printk(KERN_INFO "%s: 16k detected in step 2\n", | |
350 | eeprom_name); | |
351 | loc1[0] = ~loc1[0]; | |
352 | /* Data differs, assume 16k */ | |
353 | /* Restore data */ | |
354 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
355 | { | |
356 | success = 1; | |
357 | } | |
358 | else | |
359 | { | |
360 | printk(KERN_INFO "%s: Restore 16k failed during probe," | |
361 | " EEPROM might be corrupt!\n", eeprom_name); | |
362 | } | |
363 | ||
364 | eeprom.size = EEPROM_16KB; | |
365 | } | |
366 | } | |
367 | } | |
368 | } | |
369 | } /* read LOC1 */ | |
370 | } /* address LOC1 */ | |
371 | if (!success) | |
372 | { | |
373 | printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name); | |
374 | eeprom.size = EEPROM_2KB; | |
375 | } | |
376 | } /* read */ | |
377 | } | |
378 | } | |
379 | else | |
380 | { | |
381 | i2c_outbyte(0x00); | |
382 | if(!i2c_getack()) | |
383 | { | |
384 | /* No 8k */ | |
385 | eeprom.size = EEPROM_2KB; | |
386 | } | |
387 | else | |
388 | { | |
389 | i2c_start(); | |
390 | i2c_outbyte(0x81); | |
391 | if (!i2c_getack()) | |
392 | { | |
393 | eeprom.size = EEPROM_2KB; | |
394 | } | |
395 | else | |
396 | { | |
397 | /* It's a 8kB */ | |
398 | i2c_inbyte(); | |
399 | eeprom.size = EEPROM_8KB; | |
400 | } | |
401 | } | |
402 | } | |
403 | i2c_stop(); | |
404 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB) | |
405 | eeprom.size = EEPROM_16KB; | |
406 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB) | |
407 | eeprom.size = EEPROM_8KB; | |
408 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB) | |
409 | eeprom.size = EEPROM_2KB; | |
410 | #endif | |
411 | ||
412 | switch(eeprom.size) | |
413 | { | |
414 | case (EEPROM_2KB): | |
415 | printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name); | |
416 | eeprom.sequential_write_pagesize = 16; | |
417 | eeprom.select_cmd = 0xA0; | |
418 | break; | |
419 | case (EEPROM_8KB): | |
420 | printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name); | |
421 | eeprom.sequential_write_pagesize = 16; | |
422 | eeprom.select_cmd = 0x80; | |
423 | break; | |
424 | case (EEPROM_16KB): | |
425 | printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name); | |
426 | eeprom.sequential_write_pagesize = 64; | |
427 | eeprom.select_cmd = 0xA0; | |
428 | break; | |
429 | default: | |
430 | eeprom.size = 0; | |
431 | printk("%s: Did not find a supported eeprom\n", eeprom_name); | |
432 | break; | |
433 | } | |
434 | ||
435 | ||
436 | ||
437 | eeprom_disable_write_protect(); | |
438 | ||
439 | return 0; | |
440 | } | |
441 | ||
442 | /* Opens the device. */ | |
443 | ||
444 | static int eeprom_open(struct inode * inode, struct file * file) | |
445 | { | |
446 | ||
447 | if(MINOR(inode->i_rdev) != EEPROM_MINOR_NR) | |
448 | return -ENXIO; | |
449 | if(MAJOR(inode->i_rdev) != EEPROM_MAJOR_NR) | |
450 | return -ENXIO; | |
451 | ||
452 | if( eeprom.size > 0 ) | |
453 | { | |
454 | /* OK */ | |
455 | return 0; | |
456 | } | |
457 | ||
458 | /* No EEprom found */ | |
459 | return -EFAULT; | |
460 | } | |
461 | ||
462 | /* Changes the current file position. */ | |
463 | ||
464 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig) | |
465 | { | |
466 | /* | |
467 | * orig 0: position from begning of eeprom | |
468 | * orig 1: relative from current position | |
469 | * orig 2: position from last eeprom address | |
470 | */ | |
471 | ||
472 | switch (orig) | |
473 | { | |
474 | case 0: | |
475 | file->f_pos = offset; | |
476 | break; | |
477 | case 1: | |
478 | file->f_pos += offset; | |
479 | break; | |
480 | case 2: | |
481 | file->f_pos = eeprom.size - offset; | |
482 | break; | |
483 | default: | |
484 | return -EINVAL; | |
485 | } | |
486 | ||
487 | /* truncate position */ | |
488 | if (file->f_pos < 0) | |
489 | { | |
490 | file->f_pos = 0; | |
491 | return(-EOVERFLOW); | |
492 | } | |
493 | ||
494 | if (file->f_pos >= eeprom.size) | |
495 | { | |
496 | file->f_pos = eeprom.size - 1; | |
497 | return(-EOVERFLOW); | |
498 | } | |
499 | ||
500 | return ( file->f_pos ); | |
501 | } | |
502 | ||
503 | /* Reads data from eeprom. */ | |
504 | ||
505 | static int eeprom_read_buf(loff_t addr, char * buf, int count) | |
506 | { | |
507 | struct file f; | |
508 | ||
509 | f.f_pos = addr; | |
510 | return eeprom_read(&f, buf, count, &addr); | |
511 | } | |
512 | ||
513 | ||
514 | ||
515 | /* Reads data from eeprom. */ | |
516 | ||
517 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off) | |
518 | { | |
519 | int read=0; | |
520 | unsigned long p = file->f_pos; | |
521 | ||
522 | unsigned char page; | |
523 | ||
524 | if(p >= eeprom.size) /* Address i 0 - (size-1) */ | |
525 | { | |
526 | return -EFAULT; | |
527 | } | |
528 | ||
529 | while(eeprom.busy) | |
530 | { | |
531 | interruptible_sleep_on(&eeprom.wait_q); | |
532 | ||
533 | /* bail out if we get interrupted */ | |
534 | if (signal_pending(current)) | |
535 | return -EINTR; | |
536 | ||
537 | } | |
538 | eeprom.busy++; | |
539 | ||
540 | page = (unsigned char) (p >> 8); | |
541 | ||
542 | if(!eeprom_address(p)) | |
543 | { | |
544 | printk(KERN_INFO "%s: Read failed to address the eeprom: " | |
545 | "0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page); | |
546 | i2c_stop(); | |
547 | ||
548 | /* don't forget to wake them up */ | |
549 | eeprom.busy--; | |
550 | wake_up_interruptible(&eeprom.wait_q); | |
551 | return -EFAULT; | |
552 | } | |
553 | ||
554 | if( (p + count) > eeprom.size) | |
555 | { | |
556 | /* truncate count */ | |
557 | count = eeprom.size - p; | |
558 | } | |
559 | ||
560 | /* stop dummy write op and initiate the read op */ | |
561 | i2c_start(); | |
562 | ||
563 | /* special case for small eeproms */ | |
564 | if(eeprom.size < EEPROM_16KB) | |
565 | { | |
566 | i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) ); | |
567 | } | |
568 | ||
569 | /* go on with the actual read */ | |
570 | read = read_from_eeprom( buf, count); | |
571 | ||
572 | if(read > 0) | |
573 | { | |
574 | file->f_pos += read; | |
575 | } | |
576 | ||
577 | eeprom.busy--; | |
578 | wake_up_interruptible(&eeprom.wait_q); | |
579 | return read; | |
580 | } | |
581 | ||
582 | /* Writes data to eeprom. */ | |
583 | ||
584 | static int eeprom_write_buf(loff_t addr, const char * buf, int count) | |
585 | { | |
586 | struct file f; | |
587 | ||
588 | f.f_pos = addr; | |
589 | ||
590 | return eeprom_write(&f, buf, count, &addr); | |
591 | } | |
592 | ||
593 | ||
594 | /* Writes data to eeprom. */ | |
595 | ||
596 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
597 | loff_t *off) | |
598 | { | |
599 | int i, written, restart=1; | |
600 | unsigned long p; | |
601 | ||
602 | if (!access_ok(VERIFY_READ, buf, count)) | |
603 | { | |
604 | return -EFAULT; | |
605 | } | |
606 | ||
607 | while(eeprom.busy) | |
608 | { | |
609 | interruptible_sleep_on(&eeprom.wait_q); | |
610 | /* bail out if we get interrupted */ | |
611 | if (signal_pending(current)) | |
612 | return -EINTR; | |
613 | } | |
614 | eeprom.busy++; | |
615 | for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++) | |
616 | { | |
617 | restart = 0; | |
618 | written = 0; | |
619 | p = file->f_pos; | |
620 | ||
621 | ||
622 | while( (written < count) && (p < eeprom.size)) | |
623 | { | |
624 | /* address the eeprom */ | |
625 | if(!eeprom_address(p)) | |
626 | { | |
627 | printk(KERN_INFO "%s: Write failed to address the eeprom: " | |
628 | "0x%08X (%i) \n", eeprom_name, (int)p, (int)p); | |
629 | i2c_stop(); | |
630 | ||
631 | /* don't forget to wake them up */ | |
632 | eeprom.busy--; | |
633 | wake_up_interruptible(&eeprom.wait_q); | |
634 | return -EFAULT; | |
635 | } | |
636 | #ifdef EEPROM_ADAPTIVE_TIMING | |
637 | /* Adaptive algorithm to adjust timing */ | |
638 | if (eeprom.retry_cnt_addr > 0) | |
639 | { | |
640 | /* To Low now */ | |
641 | D(printk(">D=%i d=%i\n", | |
642 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
643 | ||
644 | if (eeprom.usec_delay_step < 4) | |
645 | { | |
646 | eeprom.usec_delay_step++; | |
647 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
648 | } | |
649 | else | |
650 | { | |
651 | ||
652 | if (eeprom.adapt_state > 0) | |
653 | { | |
654 | /* To Low before */ | |
655 | eeprom.usec_delay_step *= 2; | |
656 | if (eeprom.usec_delay_step > 2) | |
657 | { | |
658 | eeprom.usec_delay_step--; | |
659 | } | |
660 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
661 | } | |
662 | else if (eeprom.adapt_state < 0) | |
663 | { | |
664 | /* To High before (toggle dir) */ | |
665 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
666 | if (eeprom.usec_delay_step > 1) | |
667 | { | |
668 | eeprom.usec_delay_step /= 2; | |
669 | eeprom.usec_delay_step--; | |
670 | } | |
671 | } | |
672 | } | |
673 | ||
674 | eeprom.adapt_state = 1; | |
675 | } | |
676 | else | |
677 | { | |
678 | /* To High (or good) now */ | |
679 | D(printk("<D=%i d=%i\n", | |
680 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
681 | ||
682 | if (eeprom.adapt_state < 0) | |
683 | { | |
684 | /* To High before */ | |
685 | if (eeprom.usec_delay_step > 1) | |
686 | { | |
687 | eeprom.usec_delay_step *= 2; | |
688 | eeprom.usec_delay_step--; | |
689 | ||
690 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
691 | { | |
692 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
693 | } | |
694 | } | |
695 | } | |
696 | else if (eeprom.adapt_state > 0) | |
697 | { | |
698 | /* To Low before (toggle dir) */ | |
699 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
700 | { | |
701 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
702 | } | |
703 | if (eeprom.usec_delay_step > 1) | |
704 | { | |
705 | eeprom.usec_delay_step /= 2; | |
706 | eeprom.usec_delay_step--; | |
707 | } | |
708 | ||
709 | eeprom.adapt_state = -1; | |
710 | } | |
711 | ||
712 | if (eeprom.adapt_state > -100) | |
713 | { | |
714 | eeprom.adapt_state--; | |
715 | } | |
716 | else | |
717 | { | |
718 | /* Restart adaption */ | |
719 | D(printk("#Restart\n")); | |
720 | eeprom.usec_delay_step++; | |
721 | } | |
722 | } | |
723 | #endif /* EEPROM_ADAPTIVE_TIMING */ | |
724 | /* write until we hit a page boundary or count */ | |
725 | do | |
726 | { | |
727 | i2c_outbyte(buf[written]); | |
728 | if(!i2c_getack()) | |
729 | { | |
730 | restart=1; | |
731 | printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i); | |
732 | i2c_stop(); | |
733 | break; | |
734 | } | |
735 | written++; | |
736 | p++; | |
737 | } while( written < count && ( p % eeprom.sequential_write_pagesize )); | |
738 | ||
739 | /* end write cycle */ | |
740 | i2c_stop(); | |
741 | i2c_delay(eeprom.usec_delay_writecycles); | |
742 | } /* while */ | |
743 | } /* for */ | |
744 | ||
745 | eeprom.busy--; | |
746 | wake_up_interruptible(&eeprom.wait_q); | |
747 | if (written == 0 && file->f_pos >= eeprom.size){ | |
748 | return -ENOSPC; | |
749 | } | |
750 | file->f_pos += written; | |
751 | return written; | |
752 | } | |
753 | ||
754 | /* Closes the device. */ | |
755 | ||
756 | static int eeprom_close(struct inode * inode, struct file * file) | |
757 | { | |
758 | /* do nothing for now */ | |
759 | return 0; | |
760 | } | |
761 | ||
762 | /* Sets the current address of the eeprom. */ | |
763 | ||
764 | static int eeprom_address(unsigned long addr) | |
765 | { | |
766 | int i; | |
767 | unsigned char page, offset; | |
768 | ||
769 | page = (unsigned char) (addr >> 8); | |
770 | offset = (unsigned char) addr; | |
771 | ||
772 | for(i = 0; i < EEPROM_RETRIES; i++) | |
773 | { | |
774 | /* start a dummy write for addressing */ | |
775 | i2c_start(); | |
776 | ||
777 | if(eeprom.size == EEPROM_16KB) | |
778 | { | |
779 | i2c_outbyte( eeprom.select_cmd ); | |
780 | i2c_getack(); | |
781 | i2c_outbyte(page); | |
782 | } | |
783 | else | |
784 | { | |
785 | i2c_outbyte( eeprom.select_cmd | (page << 1) ); | |
786 | } | |
787 | if(!i2c_getack()) | |
788 | { | |
789 | /* retry */ | |
790 | i2c_stop(); | |
791 | /* Must have a delay here.. 500 works, >50, 100->works 5th time*/ | |
792 | i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i); | |
793 | /* The chip needs up to 10 ms from write stop to next start */ | |
794 | ||
795 | } | |
796 | else | |
797 | { | |
798 | i2c_outbyte(offset); | |
799 | ||
800 | if(!i2c_getack()) | |
801 | { | |
802 | /* retry */ | |
803 | i2c_stop(); | |
804 | } | |
805 | else | |
806 | break; | |
807 | } | |
808 | } | |
809 | ||
810 | ||
811 | eeprom.retry_cnt_addr = i; | |
812 | D(printk("%i\n", eeprom.retry_cnt_addr)); | |
813 | if(eeprom.retry_cnt_addr == EEPROM_RETRIES) | |
814 | { | |
815 | /* failed */ | |
816 | return 0; | |
817 | } | |
818 | return 1; | |
819 | } | |
820 | ||
821 | /* Reads from current address. */ | |
822 | ||
823 | static int read_from_eeprom(char * buf, int count) | |
824 | { | |
825 | int i, read=0; | |
826 | ||
827 | for(i = 0; i < EEPROM_RETRIES; i++) | |
828 | { | |
829 | if(eeprom.size == EEPROM_16KB) | |
830 | { | |
831 | i2c_outbyte( eeprom.select_cmd | 1 ); | |
832 | } | |
833 | ||
834 | if(i2c_getack()) | |
835 | { | |
836 | break; | |
837 | } | |
838 | } | |
839 | ||
840 | if(i == EEPROM_RETRIES) | |
841 | { | |
842 | printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name); | |
843 | i2c_stop(); | |
844 | ||
845 | return -EFAULT; | |
846 | } | |
847 | ||
848 | while( (read < count)) | |
849 | { | |
850 | if (put_user(i2c_inbyte(), &buf[read++])) | |
851 | { | |
852 | i2c_stop(); | |
853 | ||
854 | return -EFAULT; | |
855 | } | |
856 | ||
857 | /* | |
858 | * make sure we don't ack last byte or you will get very strange | |
859 | * results! | |
860 | */ | |
861 | if(read < count) | |
862 | { | |
863 | i2c_sendack(); | |
864 | } | |
865 | } | |
866 | ||
867 | /* stop the operation */ | |
868 | i2c_stop(); | |
869 | ||
870 | return read; | |
871 | } | |
872 | ||
873 | /* Disables write protection if applicable. */ | |
874 | ||
875 | #define DBP_SAVE(x) | |
876 | #define ax_printf printk | |
877 | static void eeprom_disable_write_protect(void) | |
878 | { | |
879 | /* Disable write protect */ | |
880 | if (eeprom.size == EEPROM_8KB) | |
881 | { | |
882 | /* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */ | |
883 | i2c_start(); | |
884 | i2c_outbyte(0xbe); | |
885 | if(!i2c_getack()) | |
886 | { | |
887 | DBP_SAVE(ax_printf("Get ack returns false\n")); | |
888 | } | |
889 | i2c_outbyte(0xFF); | |
890 | if(!i2c_getack()) | |
891 | { | |
892 | DBP_SAVE(ax_printf("Get ack returns false 2\n")); | |
893 | } | |
894 | i2c_outbyte(0x02); | |
895 | if(!i2c_getack()) | |
896 | { | |
897 | DBP_SAVE(ax_printf("Get ack returns false 3\n")); | |
898 | } | |
899 | i2c_stop(); | |
900 | ||
901 | i2c_delay(1000); | |
902 | ||
903 | /* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */ | |
904 | i2c_start(); | |
905 | i2c_outbyte(0xbe); | |
906 | if(!i2c_getack()) | |
907 | { | |
908 | DBP_SAVE(ax_printf("Get ack returns false 55\n")); | |
909 | } | |
910 | i2c_outbyte(0xFF); | |
911 | if(!i2c_getack()) | |
912 | { | |
913 | DBP_SAVE(ax_printf("Get ack returns false 52\n")); | |
914 | } | |
915 | i2c_outbyte(0x06); | |
916 | if(!i2c_getack()) | |
917 | { | |
918 | DBP_SAVE(ax_printf("Get ack returns false 53\n")); | |
919 | } | |
920 | i2c_stop(); | |
921 | ||
922 | /* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */ | |
923 | i2c_start(); | |
924 | i2c_outbyte(0xbe); | |
925 | if(!i2c_getack()) | |
926 | { | |
927 | DBP_SAVE(ax_printf("Get ack returns false 56\n")); | |
928 | } | |
929 | i2c_outbyte(0xFF); | |
930 | if(!i2c_getack()) | |
931 | { | |
932 | DBP_SAVE(ax_printf("Get ack returns false 57\n")); | |
933 | } | |
934 | i2c_outbyte(0x06); | |
935 | if(!i2c_getack()) | |
936 | { | |
937 | DBP_SAVE(ax_printf("Get ack returns false 58\n")); | |
938 | } | |
939 | i2c_stop(); | |
940 | ||
941 | /* Write protect disabled */ | |
942 | } | |
943 | } | |
944 | ||
945 | module_init(eeprom_init); |