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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /*!***************************************************************************** |
3 | *! | |
0779bf2d ML |
4 | *! Implements an interface for i2c compatible eeproms to run under Linux. |
5 | *! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustments by | |
1da177e4 LT |
6 | *! Johan.Adolfsson@axis.com |
7 | *! | |
8 | *! Probing results: | |
9 | *! 8k or not is detected (the assumes 2k or 16k) | |
10 | *! 2k or 16k detected using test reads and writes. | |
11 | *! | |
12 | *!------------------------------------------------------------------------ | |
13 | *! HISTORY | |
14 | *! | |
15 | *! DATE NAME CHANGES | |
16 | *! ---- ---- ------- | |
17 | *! Aug 28 1999 Edgar Iglesias Initial Version | |
18 | *! Aug 31 1999 Edgar Iglesias Allow simultaneous users. | |
19 | *! Sep 03 1999 Edgar Iglesias Updated probe. | |
20 | *! Sep 03 1999 Edgar Iglesias Added bail-out stuff if we get interrupted | |
21 | *! in the spin-lock. | |
22 | *! | |
1da177e4 LT |
23 | *! (c) 1999 Axis Communications AB, Lund, Sweden |
24 | *!*****************************************************************************/ | |
25 | ||
1da177e4 LT |
26 | #include <linux/kernel.h> |
27 | #include <linux/sched.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/delay.h> | |
31 | #include <linux/interrupt.h> | |
7e920426 | 32 | #include <linux/wait.h> |
7c0f6ba6 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include "i2c.h" |
35 | ||
3d6c03fc | 36 | #define D(x) |
1da177e4 LT |
37 | |
38 | /* If we should use adaptive timing or not: */ | |
3d6c03fc | 39 | /* #define EEPROM_ADAPTIVE_TIMING */ |
1da177e4 LT |
40 | |
41 | #define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */ | |
42 | #define EEPROM_MINOR_NR 0 | |
43 | ||
44 | /* Empirical sane initial value of the delay, the value will be adapted to | |
45 | * what the chip needs when using EEPROM_ADAPTIVE_TIMING. | |
46 | */ | |
47 | #define INITIAL_WRITEDELAY_US 4000 | |
48 | #define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */ | |
49 | ||
50 | /* This one defines how many times to try when eeprom fails. */ | |
51 | #define EEPROM_RETRIES 10 | |
52 | ||
53 | #define EEPROM_2KB (2 * 1024) | |
54 | /*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */ | |
55 | #define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */ | |
56 | #define EEPROM_16KB (16 * 1024) | |
57 | ||
58 | #define i2c_delay(x) udelay(x) | |
59 | ||
60 | /* | |
61 | * This structure describes the attached eeprom chip. | |
62 | * The values are probed for. | |
63 | */ | |
64 | ||
65 | struct eeprom_type | |
66 | { | |
67 | unsigned long size; | |
68 | unsigned long sequential_write_pagesize; | |
69 | unsigned char select_cmd; | |
70 | unsigned long usec_delay_writecycles; /* Min time between write cycles | |
71 | (up to 10ms for some models) */ | |
72 | unsigned long usec_delay_step; /* For adaptive algorithm */ | |
73 | int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */ | |
74 | ||
75 | /* this one is to keep the read/write operations atomic */ | |
4f0447b8 | 76 | struct mutex lock; |
1da177e4 LT |
77 | int retry_cnt_addr; /* Used to keep track of number of retries for |
78 | adaptive timing adjustments */ | |
79 | int retry_cnt_read; | |
80 | }; | |
81 | ||
82 | static int eeprom_open(struct inode * inode, struct file * file); | |
83 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig); | |
84 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, | |
85 | loff_t *off); | |
86 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
87 | loff_t *off); | |
88 | static int eeprom_close(struct inode * inode, struct file * file); | |
89 | ||
90 | static int eeprom_address(unsigned long addr); | |
91 | static int read_from_eeprom(char * buf, int count); | |
92 | static int eeprom_write_buf(loff_t addr, const char * buf, int count); | |
93 | static int eeprom_read_buf(loff_t addr, char * buf, int count); | |
94 | ||
95 | static void eeprom_disable_write_protect(void); | |
96 | ||
97 | ||
98 | static const char eeprom_name[] = "eeprom"; | |
99 | ||
100 | /* chip description */ | |
101 | static struct eeprom_type eeprom; | |
102 | ||
103 | /* This is the exported file-operations structure for this device. */ | |
5dfe4c96 | 104 | const struct file_operations eeprom_fops = |
1da177e4 LT |
105 | { |
106 | .llseek = eeprom_lseek, | |
107 | .read = eeprom_read, | |
108 | .write = eeprom_write, | |
109 | .open = eeprom_open, | |
110 | .release = eeprom_close | |
111 | }; | |
112 | ||
113 | /* eeprom init call. Probes for different eeprom models. */ | |
114 | ||
115 | int __init eeprom_init(void) | |
116 | { | |
4f0447b8 | 117 | mutex_init(&eeprom.lock); |
1da177e4 LT |
118 | |
119 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
120 | #define EETEXT "Found" | |
121 | #else | |
122 | #define EETEXT "Assuming" | |
123 | #endif | |
124 | if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops)) | |
125 | { | |
126 | printk(KERN_INFO "%s: unable to get major %d for eeprom device\n", | |
127 | eeprom_name, EEPROM_MAJOR_NR); | |
128 | return -1; | |
129 | } | |
130 | ||
131 | printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n"); | |
132 | ||
133 | /* | |
134 | * Note: Most of this probing method was taken from the printserver (5470e) | |
135 | * codebase. It did not contain a way of finding the 16kB chips | |
136 | * (M24128 or variants). The method used here might not work | |
137 | * for all models. If you encounter problems the easiest way | |
138 | * is probably to define your model within #ifdef's, and hard- | |
139 | * code it. | |
140 | */ | |
141 | ||
142 | eeprom.size = 0; | |
143 | eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US; | |
144 | eeprom.usec_delay_step = 128; | |
145 | eeprom.adapt_state = 0; | |
146 | ||
147 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE | |
148 | i2c_start(); | |
149 | i2c_outbyte(0x80); | |
150 | if(!i2c_getack()) | |
151 | { | |
152 | /* It's not 8k.. */ | |
153 | int success = 0; | |
154 | unsigned char buf_2k_start[16]; | |
155 | ||
156 | /* Im not sure this will work... :) */ | |
157 | /* assume 2kB, if failure go for 16kB */ | |
158 | /* Test with 16kB settings.. */ | |
159 | /* If it's a 2kB EEPROM and we address it outside it's range | |
160 | * it will mirror the address space: | |
161 | * 1. We read two locations (that are mirrored), | |
162 | * if the content differs * it's a 16kB EEPROM. | |
163 | * 2. if it doesn't differ - write different value to one of the locations, | |
164 | * check the other - if content still is the same it's a 2k EEPROM, | |
165 | * restore original data. | |
166 | */ | |
167 | #define LOC1 8 | |
168 | #define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */ | |
169 | ||
170 | /* 2k settings */ | |
171 | i2c_stop(); | |
172 | eeprom.size = EEPROM_2KB; | |
173 | eeprom.select_cmd = 0xA0; | |
174 | eeprom.sequential_write_pagesize = 16; | |
175 | if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 ) | |
176 | { | |
177 | D(printk("2k start: '%16.16s'\n", buf_2k_start)); | |
178 | } | |
179 | else | |
180 | { | |
181 | printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name); | |
182 | } | |
183 | ||
184 | /* 16k settings */ | |
185 | eeprom.size = EEPROM_16KB; | |
186 | eeprom.select_cmd = 0xA0; | |
187 | eeprom.sequential_write_pagesize = 64; | |
188 | ||
189 | { | |
190 | unsigned char loc1[4], loc2[4], tmp[4]; | |
191 | if( eeprom_read_buf(LOC2, loc2, 4) == 4) | |
192 | { | |
193 | if( eeprom_read_buf(LOC1, loc1, 4) == 4) | |
194 | { | |
195 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
196 | LOC1, loc1, LOC2, loc2)); | |
197 | #if 0 | |
198 | if (memcmp(loc1, loc2, 4) != 0 ) | |
199 | { | |
200 | /* It's 16k */ | |
201 | printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name); | |
202 | eeprom.size = EEPROM_16KB; | |
203 | success = 1; | |
204 | } | |
205 | else | |
206 | #endif | |
207 | { | |
208 | /* Do step 2 check */ | |
209 | /* Invert value */ | |
210 | loc1[0] = ~loc1[0]; | |
211 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
212 | { | |
213 | /* If 2k EEPROM this write will actually write 10 bytes | |
214 | * from pos 0 | |
215 | */ | |
216 | D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
217 | LOC1, loc1, LOC2, loc2)); | |
218 | if( eeprom_read_buf(LOC1, tmp, 4) == 4) | |
219 | { | |
220 | D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n", | |
221 | LOC1, loc1, tmp)); | |
222 | if (memcmp(loc1, tmp, 4) != 0 ) | |
223 | { | |
224 | printk(KERN_INFO "%s: read and write differs! Not 16kB\n", | |
225 | eeprom_name); | |
226 | loc1[0] = ~loc1[0]; | |
227 | ||
228 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
229 | { | |
230 | success = 1; | |
231 | } | |
232 | else | |
233 | { | |
234 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
235 | " EEPROM might be corrupt!\n", eeprom_name); | |
236 | ||
237 | } | |
238 | i2c_stop(); | |
239 | /* Go to 2k mode and write original data */ | |
240 | eeprom.size = EEPROM_2KB; | |
241 | eeprom.select_cmd = 0xA0; | |
242 | eeprom.sequential_write_pagesize = 16; | |
243 | if( eeprom_write_buf(0, buf_2k_start, 16) == 16) | |
244 | { | |
245 | } | |
246 | else | |
247 | { | |
248 | printk(KERN_INFO "%s: Failed to write back 2k start!\n", | |
249 | eeprom_name); | |
250 | } | |
251 | ||
252 | eeprom.size = EEPROM_2KB; | |
253 | } | |
254 | } | |
255 | ||
256 | if(!success) | |
257 | { | |
258 | if( eeprom_read_buf(LOC2, loc2, 1) == 1) | |
259 | { | |
260 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", | |
261 | LOC1, loc1, LOC2, loc2)); | |
262 | if (memcmp(loc1, loc2, 4) == 0 ) | |
263 | { | |
264 | /* Data the same, must be mirrored -> 2k */ | |
265 | /* Restore data */ | |
266 | printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name); | |
267 | loc1[0] = ~loc1[0]; | |
268 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
269 | { | |
270 | success = 1; | |
271 | } | |
272 | else | |
273 | { | |
274 | printk(KERN_INFO "%s: Restore 2k failed during probe," | |
275 | " EEPROM might be corrupt!\n", eeprom_name); | |
276 | ||
277 | } | |
278 | ||
279 | eeprom.size = EEPROM_2KB; | |
280 | } | |
281 | else | |
282 | { | |
283 | printk(KERN_INFO "%s: 16k detected in step 2\n", | |
284 | eeprom_name); | |
285 | loc1[0] = ~loc1[0]; | |
286 | /* Data differs, assume 16k */ | |
287 | /* Restore data */ | |
288 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) | |
289 | { | |
290 | success = 1; | |
291 | } | |
292 | else | |
293 | { | |
294 | printk(KERN_INFO "%s: Restore 16k failed during probe," | |
295 | " EEPROM might be corrupt!\n", eeprom_name); | |
296 | } | |
297 | ||
298 | eeprom.size = EEPROM_16KB; | |
299 | } | |
300 | } | |
301 | } | |
302 | } | |
303 | } /* read LOC1 */ | |
304 | } /* address LOC1 */ | |
305 | if (!success) | |
306 | { | |
307 | printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name); | |
308 | eeprom.size = EEPROM_2KB; | |
309 | } | |
310 | } /* read */ | |
311 | } | |
312 | } | |
313 | else | |
314 | { | |
315 | i2c_outbyte(0x00); | |
316 | if(!i2c_getack()) | |
317 | { | |
318 | /* No 8k */ | |
319 | eeprom.size = EEPROM_2KB; | |
320 | } | |
321 | else | |
322 | { | |
323 | i2c_start(); | |
324 | i2c_outbyte(0x81); | |
325 | if (!i2c_getack()) | |
326 | { | |
327 | eeprom.size = EEPROM_2KB; | |
328 | } | |
329 | else | |
330 | { | |
331 | /* It's a 8kB */ | |
332 | i2c_inbyte(); | |
333 | eeprom.size = EEPROM_8KB; | |
334 | } | |
335 | } | |
336 | } | |
337 | i2c_stop(); | |
338 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB) | |
339 | eeprom.size = EEPROM_16KB; | |
340 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB) | |
341 | eeprom.size = EEPROM_8KB; | |
342 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB) | |
343 | eeprom.size = EEPROM_2KB; | |
344 | #endif | |
345 | ||
346 | switch(eeprom.size) | |
347 | { | |
348 | case (EEPROM_2KB): | |
349 | printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name); | |
350 | eeprom.sequential_write_pagesize = 16; | |
351 | eeprom.select_cmd = 0xA0; | |
352 | break; | |
353 | case (EEPROM_8KB): | |
354 | printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name); | |
355 | eeprom.sequential_write_pagesize = 16; | |
356 | eeprom.select_cmd = 0x80; | |
357 | break; | |
358 | case (EEPROM_16KB): | |
359 | printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name); | |
360 | eeprom.sequential_write_pagesize = 64; | |
361 | eeprom.select_cmd = 0xA0; | |
362 | break; | |
363 | default: | |
364 | eeprom.size = 0; | |
365 | printk("%s: Did not find a supported eeprom\n", eeprom_name); | |
366 | break; | |
367 | } | |
368 | ||
369 | ||
370 | ||
371 | eeprom_disable_write_protect(); | |
372 | ||
373 | return 0; | |
374 | } | |
375 | ||
376 | /* Opens the device. */ | |
1da177e4 LT |
377 | static int eeprom_open(struct inode * inode, struct file * file) |
378 | { | |
32ea086b | 379 | if(iminor(inode) != EEPROM_MINOR_NR) |
1da177e4 | 380 | return -ENXIO; |
32ea086b | 381 | if(imajor(inode) != EEPROM_MAJOR_NR) |
1da177e4 LT |
382 | return -ENXIO; |
383 | ||
384 | if( eeprom.size > 0 ) | |
385 | { | |
386 | /* OK */ | |
387 | return 0; | |
388 | } | |
389 | ||
390 | /* No EEprom found */ | |
391 | return -EFAULT; | |
392 | } | |
393 | ||
394 | /* Changes the current file position. */ | |
395 | ||
396 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig) | |
397 | { | |
398 | /* | |
8d59dc11 | 399 | * orig 0: position from beginning of eeprom |
1da177e4 LT |
400 | * orig 1: relative from current position |
401 | * orig 2: position from last eeprom address | |
402 | */ | |
403 | ||
404 | switch (orig) | |
405 | { | |
406 | case 0: | |
407 | file->f_pos = offset; | |
408 | break; | |
409 | case 1: | |
410 | file->f_pos += offset; | |
411 | break; | |
412 | case 2: | |
413 | file->f_pos = eeprom.size - offset; | |
414 | break; | |
415 | default: | |
416 | return -EINVAL; | |
417 | } | |
418 | ||
419 | /* truncate position */ | |
420 | if (file->f_pos < 0) | |
421 | { | |
422 | file->f_pos = 0; | |
423 | return(-EOVERFLOW); | |
424 | } | |
425 | ||
426 | if (file->f_pos >= eeprom.size) | |
427 | { | |
428 | file->f_pos = eeprom.size - 1; | |
429 | return(-EOVERFLOW); | |
430 | } | |
431 | ||
432 | return ( file->f_pos ); | |
433 | } | |
434 | ||
435 | /* Reads data from eeprom. */ | |
436 | ||
437 | static int eeprom_read_buf(loff_t addr, char * buf, int count) | |
438 | { | |
82f3952c | 439 | return eeprom_read(NULL, buf, count, &addr); |
1da177e4 LT |
440 | } |
441 | ||
442 | ||
443 | ||
444 | /* Reads data from eeprom. */ | |
445 | ||
446 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off) | |
447 | { | |
448 | int read=0; | |
82f3952c | 449 | unsigned long p = *off; |
1da177e4 LT |
450 | |
451 | unsigned char page; | |
452 | ||
453 | if(p >= eeprom.size) /* Address i 0 - (size-1) */ | |
454 | { | |
455 | return -EFAULT; | |
456 | } | |
457 | ||
4f0447b8 | 458 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 459 | return -EINTR; |
1da177e4 | 460 | |
1da177e4 LT |
461 | page = (unsigned char) (p >> 8); |
462 | ||
463 | if(!eeprom_address(p)) | |
464 | { | |
465 | printk(KERN_INFO "%s: Read failed to address the eeprom: " | |
466 | "0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page); | |
467 | i2c_stop(); | |
468 | ||
469 | /* don't forget to wake them up */ | |
4f0447b8 | 470 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
471 | return -EFAULT; |
472 | } | |
473 | ||
474 | if( (p + count) > eeprom.size) | |
475 | { | |
476 | /* truncate count */ | |
477 | count = eeprom.size - p; | |
478 | } | |
479 | ||
480 | /* stop dummy write op and initiate the read op */ | |
481 | i2c_start(); | |
482 | ||
483 | /* special case for small eeproms */ | |
484 | if(eeprom.size < EEPROM_16KB) | |
485 | { | |
486 | i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) ); | |
487 | } | |
488 | ||
489 | /* go on with the actual read */ | |
490 | read = read_from_eeprom( buf, count); | |
491 | ||
492 | if(read > 0) | |
493 | { | |
82f3952c | 494 | *off += read; |
1da177e4 LT |
495 | } |
496 | ||
4f0447b8 | 497 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
498 | return read; |
499 | } | |
500 | ||
501 | /* Writes data to eeprom. */ | |
502 | ||
503 | static int eeprom_write_buf(loff_t addr, const char * buf, int count) | |
504 | { | |
82f3952c | 505 | return eeprom_write(NULL, buf, count, &addr); |
1da177e4 LT |
506 | } |
507 | ||
508 | ||
509 | /* Writes data to eeprom. */ | |
510 | ||
511 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
512 | loff_t *off) | |
513 | { | |
514 | int i, written, restart=1; | |
515 | unsigned long p; | |
516 | ||
517 | if (!access_ok(VERIFY_READ, buf, count)) | |
518 | { | |
519 | return -EFAULT; | |
520 | } | |
521 | ||
7e920426 | 522 | /* bail out if we get interrupted */ |
4f0447b8 | 523 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 524 | return -EINTR; |
1da177e4 LT |
525 | for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++) |
526 | { | |
527 | restart = 0; | |
528 | written = 0; | |
82f3952c | 529 | p = *off; |
1da177e4 LT |
530 | |
531 | ||
532 | while( (written < count) && (p < eeprom.size)) | |
533 | { | |
534 | /* address the eeprom */ | |
535 | if(!eeprom_address(p)) | |
536 | { | |
537 | printk(KERN_INFO "%s: Write failed to address the eeprom: " | |
538 | "0x%08X (%i) \n", eeprom_name, (int)p, (int)p); | |
539 | i2c_stop(); | |
540 | ||
541 | /* don't forget to wake them up */ | |
4f0447b8 | 542 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
543 | return -EFAULT; |
544 | } | |
545 | #ifdef EEPROM_ADAPTIVE_TIMING | |
546 | /* Adaptive algorithm to adjust timing */ | |
547 | if (eeprom.retry_cnt_addr > 0) | |
548 | { | |
549 | /* To Low now */ | |
550 | D(printk(">D=%i d=%i\n", | |
551 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
552 | ||
553 | if (eeprom.usec_delay_step < 4) | |
554 | { | |
555 | eeprom.usec_delay_step++; | |
556 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
557 | } | |
558 | else | |
559 | { | |
560 | ||
561 | if (eeprom.adapt_state > 0) | |
562 | { | |
563 | /* To Low before */ | |
564 | eeprom.usec_delay_step *= 2; | |
565 | if (eeprom.usec_delay_step > 2) | |
566 | { | |
567 | eeprom.usec_delay_step--; | |
568 | } | |
569 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
570 | } | |
571 | else if (eeprom.adapt_state < 0) | |
572 | { | |
573 | /* To High before (toggle dir) */ | |
574 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
575 | if (eeprom.usec_delay_step > 1) | |
576 | { | |
577 | eeprom.usec_delay_step /= 2; | |
578 | eeprom.usec_delay_step--; | |
579 | } | |
580 | } | |
581 | } | |
582 | ||
583 | eeprom.adapt_state = 1; | |
584 | } | |
585 | else | |
586 | { | |
587 | /* To High (or good) now */ | |
588 | D(printk("<D=%i d=%i\n", | |
589 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
590 | ||
591 | if (eeprom.adapt_state < 0) | |
592 | { | |
593 | /* To High before */ | |
594 | if (eeprom.usec_delay_step > 1) | |
595 | { | |
596 | eeprom.usec_delay_step *= 2; | |
597 | eeprom.usec_delay_step--; | |
598 | ||
599 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
600 | { | |
601 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
602 | } | |
603 | } | |
604 | } | |
605 | else if (eeprom.adapt_state > 0) | |
606 | { | |
607 | /* To Low before (toggle dir) */ | |
608 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
609 | { | |
610 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
611 | } | |
612 | if (eeprom.usec_delay_step > 1) | |
613 | { | |
614 | eeprom.usec_delay_step /= 2; | |
615 | eeprom.usec_delay_step--; | |
616 | } | |
617 | ||
618 | eeprom.adapt_state = -1; | |
619 | } | |
620 | ||
621 | if (eeprom.adapt_state > -100) | |
622 | { | |
623 | eeprom.adapt_state--; | |
624 | } | |
625 | else | |
626 | { | |
627 | /* Restart adaption */ | |
628 | D(printk("#Restart\n")); | |
629 | eeprom.usec_delay_step++; | |
630 | } | |
631 | } | |
632 | #endif /* EEPROM_ADAPTIVE_TIMING */ | |
633 | /* write until we hit a page boundary or count */ | |
634 | do | |
635 | { | |
636 | i2c_outbyte(buf[written]); | |
637 | if(!i2c_getack()) | |
638 | { | |
639 | restart=1; | |
640 | printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i); | |
641 | i2c_stop(); | |
642 | break; | |
643 | } | |
644 | written++; | |
645 | p++; | |
646 | } while( written < count && ( p % eeprom.sequential_write_pagesize )); | |
647 | ||
648 | /* end write cycle */ | |
649 | i2c_stop(); | |
650 | i2c_delay(eeprom.usec_delay_writecycles); | |
651 | } /* while */ | |
652 | } /* for */ | |
653 | ||
4f0447b8 | 654 | mutex_unlock(&eeprom.lock); |
82f3952c | 655 | if (written == 0 && p >= eeprom.size){ |
1da177e4 LT |
656 | return -ENOSPC; |
657 | } | |
82f3952c | 658 | *off = p; |
1da177e4 LT |
659 | return written; |
660 | } | |
661 | ||
662 | /* Closes the device. */ | |
663 | ||
664 | static int eeprom_close(struct inode * inode, struct file * file) | |
665 | { | |
666 | /* do nothing for now */ | |
667 | return 0; | |
668 | } | |
669 | ||
670 | /* Sets the current address of the eeprom. */ | |
671 | ||
672 | static int eeprom_address(unsigned long addr) | |
673 | { | |
674 | int i; | |
675 | unsigned char page, offset; | |
676 | ||
677 | page = (unsigned char) (addr >> 8); | |
678 | offset = (unsigned char) addr; | |
679 | ||
680 | for(i = 0; i < EEPROM_RETRIES; i++) | |
681 | { | |
682 | /* start a dummy write for addressing */ | |
683 | i2c_start(); | |
684 | ||
685 | if(eeprom.size == EEPROM_16KB) | |
686 | { | |
687 | i2c_outbyte( eeprom.select_cmd ); | |
688 | i2c_getack(); | |
689 | i2c_outbyte(page); | |
690 | } | |
691 | else | |
692 | { | |
693 | i2c_outbyte( eeprom.select_cmd | (page << 1) ); | |
694 | } | |
695 | if(!i2c_getack()) | |
696 | { | |
697 | /* retry */ | |
698 | i2c_stop(); | |
699 | /* Must have a delay here.. 500 works, >50, 100->works 5th time*/ | |
700 | i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i); | |
701 | /* The chip needs up to 10 ms from write stop to next start */ | |
702 | ||
703 | } | |
704 | else | |
705 | { | |
706 | i2c_outbyte(offset); | |
707 | ||
708 | if(!i2c_getack()) | |
709 | { | |
710 | /* retry */ | |
711 | i2c_stop(); | |
712 | } | |
713 | else | |
714 | break; | |
715 | } | |
716 | } | |
717 | ||
718 | ||
719 | eeprom.retry_cnt_addr = i; | |
720 | D(printk("%i\n", eeprom.retry_cnt_addr)); | |
721 | if(eeprom.retry_cnt_addr == EEPROM_RETRIES) | |
722 | { | |
723 | /* failed */ | |
724 | return 0; | |
725 | } | |
726 | return 1; | |
727 | } | |
728 | ||
729 | /* Reads from current address. */ | |
730 | ||
731 | static int read_from_eeprom(char * buf, int count) | |
732 | { | |
733 | int i, read=0; | |
734 | ||
735 | for(i = 0; i < EEPROM_RETRIES; i++) | |
736 | { | |
737 | if(eeprom.size == EEPROM_16KB) | |
738 | { | |
739 | i2c_outbyte( eeprom.select_cmd | 1 ); | |
740 | } | |
741 | ||
742 | if(i2c_getack()) | |
743 | { | |
744 | break; | |
745 | } | |
746 | } | |
747 | ||
748 | if(i == EEPROM_RETRIES) | |
749 | { | |
750 | printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name); | |
751 | i2c_stop(); | |
752 | ||
753 | return -EFAULT; | |
754 | } | |
755 | ||
756 | while( (read < count)) | |
757 | { | |
758 | if (put_user(i2c_inbyte(), &buf[read++])) | |
759 | { | |
760 | i2c_stop(); | |
761 | ||
762 | return -EFAULT; | |
763 | } | |
764 | ||
765 | /* | |
766 | * make sure we don't ack last byte or you will get very strange | |
767 | * results! | |
768 | */ | |
769 | if(read < count) | |
770 | { | |
771 | i2c_sendack(); | |
772 | } | |
773 | } | |
774 | ||
775 | /* stop the operation */ | |
776 | i2c_stop(); | |
777 | ||
778 | return read; | |
779 | } | |
780 | ||
781 | /* Disables write protection if applicable. */ | |
782 | ||
783 | #define DBP_SAVE(x) | |
784 | #define ax_printf printk | |
785 | static void eeprom_disable_write_protect(void) | |
786 | { | |
787 | /* Disable write protect */ | |
788 | if (eeprom.size == EEPROM_8KB) | |
789 | { | |
790 | /* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */ | |
791 | i2c_start(); | |
792 | i2c_outbyte(0xbe); | |
793 | if(!i2c_getack()) | |
794 | { | |
795 | DBP_SAVE(ax_printf("Get ack returns false\n")); | |
796 | } | |
797 | i2c_outbyte(0xFF); | |
798 | if(!i2c_getack()) | |
799 | { | |
800 | DBP_SAVE(ax_printf("Get ack returns false 2\n")); | |
801 | } | |
802 | i2c_outbyte(0x02); | |
803 | if(!i2c_getack()) | |
804 | { | |
805 | DBP_SAVE(ax_printf("Get ack returns false 3\n")); | |
806 | } | |
807 | i2c_stop(); | |
808 | ||
809 | i2c_delay(1000); | |
810 | ||
811 | /* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */ | |
812 | i2c_start(); | |
813 | i2c_outbyte(0xbe); | |
814 | if(!i2c_getack()) | |
815 | { | |
816 | DBP_SAVE(ax_printf("Get ack returns false 55\n")); | |
817 | } | |
818 | i2c_outbyte(0xFF); | |
819 | if(!i2c_getack()) | |
820 | { | |
821 | DBP_SAVE(ax_printf("Get ack returns false 52\n")); | |
822 | } | |
823 | i2c_outbyte(0x06); | |
824 | if(!i2c_getack()) | |
825 | { | |
826 | DBP_SAVE(ax_printf("Get ack returns false 53\n")); | |
827 | } | |
828 | i2c_stop(); | |
829 | ||
830 | /* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */ | |
831 | i2c_start(); | |
832 | i2c_outbyte(0xbe); | |
833 | if(!i2c_getack()) | |
834 | { | |
835 | DBP_SAVE(ax_printf("Get ack returns false 56\n")); | |
836 | } | |
837 | i2c_outbyte(0xFF); | |
838 | if(!i2c_getack()) | |
839 | { | |
840 | DBP_SAVE(ax_printf("Get ack returns false 57\n")); | |
841 | } | |
842 | i2c_outbyte(0x06); | |
843 | if(!i2c_getack()) | |
844 | { | |
845 | DBP_SAVE(ax_printf("Get ack returns false 58\n")); | |
846 | } | |
847 | i2c_stop(); | |
848 | ||
849 | /* Write protect disabled */ | |
850 | } | |
851 | } | |
84c3e5bf | 852 | device_initcall(eeprom_init); |