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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/cris/arch-v10/drivers/eeprom.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/cris/arch-v10/drivers/eeprom.c')
-rw-r--r--arch/cris/arch-v10/drivers/eeprom.c945
1 files changed, 945 insertions, 0 deletions
diff --git a/arch/cris/arch-v10/drivers/eeprom.c b/arch/cris/arch-v10/drivers/eeprom.c
new file mode 100644
index 000000000000..316ca15d6802
--- /dev/null
+++ b/arch/cris/arch-v10/drivers/eeprom.c
@@ -0,0 +1,945 @@
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
129struct 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
147static int eeprom_open(struct inode * inode, struct file * file);
148static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig);
149static ssize_t eeprom_read(struct file * file, char * buf, size_t count,
150 loff_t *off);
151static ssize_t eeprom_write(struct file * file, const char * buf, size_t count,
152 loff_t *off);
153static int eeprom_close(struct inode * inode, struct file * file);
154
155static int eeprom_address(unsigned long addr);
156static int read_from_eeprom(char * buf, int count);
157static int eeprom_write_buf(loff_t addr, const char * buf, int count);
158static int eeprom_read_buf(loff_t addr, char * buf, int count);
159
160static void eeprom_disable_write_protect(void);
161
162
163static const char eeprom_name[] = "eeprom";
164
165/* chip description */
166static struct eeprom_type eeprom;
167
168/* This is the exported file-operations structure for this device. */
169struct 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
180int __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
444static 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
464static 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
505static 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
517static 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
584static 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
596static 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
756static 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
764static 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
823static 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
877static 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
945module_init(eeprom_init);
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-14 17:55:29 -0500