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1da177e4 LT |
1 | /*!***************************************************************************** |
2 | *! | |
0779bf2d ML |
3 | *! Implements an interface for i2c compatible eeproms to run under Linux. |
4 | *! Supports 2k, 8k(?) and 16k. Uses adaptive timing adjustments by | |
1da177e4 LT |
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 | *! | |
1da177e4 LT |
22 | *! (c) 1999 Axis Communications AB, Lund, Sweden |
23 | *!*****************************************************************************/ | |
24 | ||
1da177e4 LT |
25 | #include <linux/kernel.h> |
26 | #include <linux/sched.h> | |
27 | #include <linux/fs.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/delay.h> | |
30 | #include <linux/interrupt.h> | |
f2b9857e | 31 | #include <linux/smp_lock.h> |
7e920426 | 32 | #include <linux/wait.h> |
1da177e4 LT |
33 | #include <asm/uaccess.h> |
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 | { | |
f2b9857e | 379 | cycle_kernel_lock(); |
32ea086b | 380 | if(iminor(inode) != EEPROM_MINOR_NR) |
1da177e4 | 381 | return -ENXIO; |
32ea086b | 382 | if(imajor(inode) != EEPROM_MAJOR_NR) |
1da177e4 LT |
383 | return -ENXIO; |
384 | ||
385 | if( eeprom.size > 0 ) | |
386 | { | |
387 | /* OK */ | |
388 | return 0; | |
389 | } | |
390 | ||
391 | /* No EEprom found */ | |
392 | return -EFAULT; | |
393 | } | |
394 | ||
395 | /* Changes the current file position. */ | |
396 | ||
397 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig) | |
398 | { | |
399 | /* | |
400 | * orig 0: position from begning of eeprom | |
401 | * orig 1: relative from current position | |
402 | * orig 2: position from last eeprom address | |
403 | */ | |
404 | ||
405 | switch (orig) | |
406 | { | |
407 | case 0: | |
408 | file->f_pos = offset; | |
409 | break; | |
410 | case 1: | |
411 | file->f_pos += offset; | |
412 | break; | |
413 | case 2: | |
414 | file->f_pos = eeprom.size - offset; | |
415 | break; | |
416 | default: | |
417 | return -EINVAL; | |
418 | } | |
419 | ||
420 | /* truncate position */ | |
421 | if (file->f_pos < 0) | |
422 | { | |
423 | file->f_pos = 0; | |
424 | return(-EOVERFLOW); | |
425 | } | |
426 | ||
427 | if (file->f_pos >= eeprom.size) | |
428 | { | |
429 | file->f_pos = eeprom.size - 1; | |
430 | return(-EOVERFLOW); | |
431 | } | |
432 | ||
433 | return ( file->f_pos ); | |
434 | } | |
435 | ||
436 | /* Reads data from eeprom. */ | |
437 | ||
438 | static int eeprom_read_buf(loff_t addr, char * buf, int count) | |
439 | { | |
82f3952c | 440 | return eeprom_read(NULL, buf, count, &addr); |
1da177e4 LT |
441 | } |
442 | ||
443 | ||
444 | ||
445 | /* Reads data from eeprom. */ | |
446 | ||
447 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off) | |
448 | { | |
449 | int read=0; | |
82f3952c | 450 | unsigned long p = *off; |
1da177e4 LT |
451 | |
452 | unsigned char page; | |
453 | ||
454 | if(p >= eeprom.size) /* Address i 0 - (size-1) */ | |
455 | { | |
456 | return -EFAULT; | |
457 | } | |
458 | ||
4f0447b8 | 459 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 460 | return -EINTR; |
1da177e4 | 461 | |
1da177e4 LT |
462 | page = (unsigned char) (p >> 8); |
463 | ||
464 | if(!eeprom_address(p)) | |
465 | { | |
466 | printk(KERN_INFO "%s: Read failed to address the eeprom: " | |
467 | "0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page); | |
468 | i2c_stop(); | |
469 | ||
470 | /* don't forget to wake them up */ | |
4f0447b8 | 471 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
472 | return -EFAULT; |
473 | } | |
474 | ||
475 | if( (p + count) > eeprom.size) | |
476 | { | |
477 | /* truncate count */ | |
478 | count = eeprom.size - p; | |
479 | } | |
480 | ||
481 | /* stop dummy write op and initiate the read op */ | |
482 | i2c_start(); | |
483 | ||
484 | /* special case for small eeproms */ | |
485 | if(eeprom.size < EEPROM_16KB) | |
486 | { | |
487 | i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) ); | |
488 | } | |
489 | ||
490 | /* go on with the actual read */ | |
491 | read = read_from_eeprom( buf, count); | |
492 | ||
493 | if(read > 0) | |
494 | { | |
82f3952c | 495 | *off += read; |
1da177e4 LT |
496 | } |
497 | ||
4f0447b8 | 498 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
499 | return read; |
500 | } | |
501 | ||
502 | /* Writes data to eeprom. */ | |
503 | ||
504 | static int eeprom_write_buf(loff_t addr, const char * buf, int count) | |
505 | { | |
82f3952c | 506 | return eeprom_write(NULL, buf, count, &addr); |
1da177e4 LT |
507 | } |
508 | ||
509 | ||
510 | /* Writes data to eeprom. */ | |
511 | ||
512 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, | |
513 | loff_t *off) | |
514 | { | |
515 | int i, written, restart=1; | |
516 | unsigned long p; | |
517 | ||
518 | if (!access_ok(VERIFY_READ, buf, count)) | |
519 | { | |
520 | return -EFAULT; | |
521 | } | |
522 | ||
7e920426 | 523 | /* bail out if we get interrupted */ |
4f0447b8 | 524 | if (mutex_lock_interruptible(&eeprom.lock)) |
7e920426 | 525 | return -EINTR; |
1da177e4 LT |
526 | for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++) |
527 | { | |
528 | restart = 0; | |
529 | written = 0; | |
82f3952c | 530 | p = *off; |
1da177e4 LT |
531 | |
532 | ||
533 | while( (written < count) && (p < eeprom.size)) | |
534 | { | |
535 | /* address the eeprom */ | |
536 | if(!eeprom_address(p)) | |
537 | { | |
538 | printk(KERN_INFO "%s: Write failed to address the eeprom: " | |
539 | "0x%08X (%i) \n", eeprom_name, (int)p, (int)p); | |
540 | i2c_stop(); | |
541 | ||
542 | /* don't forget to wake them up */ | |
4f0447b8 | 543 | mutex_unlock(&eeprom.lock); |
1da177e4 LT |
544 | return -EFAULT; |
545 | } | |
546 | #ifdef EEPROM_ADAPTIVE_TIMING | |
547 | /* Adaptive algorithm to adjust timing */ | |
548 | if (eeprom.retry_cnt_addr > 0) | |
549 | { | |
550 | /* To Low now */ | |
551 | D(printk(">D=%i d=%i\n", | |
552 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
553 | ||
554 | if (eeprom.usec_delay_step < 4) | |
555 | { | |
556 | eeprom.usec_delay_step++; | |
557 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
558 | } | |
559 | else | |
560 | { | |
561 | ||
562 | if (eeprom.adapt_state > 0) | |
563 | { | |
564 | /* To Low before */ | |
565 | eeprom.usec_delay_step *= 2; | |
566 | if (eeprom.usec_delay_step > 2) | |
567 | { | |
568 | eeprom.usec_delay_step--; | |
569 | } | |
570 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
571 | } | |
572 | else if (eeprom.adapt_state < 0) | |
573 | { | |
574 | /* To High before (toggle dir) */ | |
575 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; | |
576 | if (eeprom.usec_delay_step > 1) | |
577 | { | |
578 | eeprom.usec_delay_step /= 2; | |
579 | eeprom.usec_delay_step--; | |
580 | } | |
581 | } | |
582 | } | |
583 | ||
584 | eeprom.adapt_state = 1; | |
585 | } | |
586 | else | |
587 | { | |
588 | /* To High (or good) now */ | |
589 | D(printk("<D=%i d=%i\n", | |
590 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); | |
591 | ||
592 | if (eeprom.adapt_state < 0) | |
593 | { | |
594 | /* To High before */ | |
595 | if (eeprom.usec_delay_step > 1) | |
596 | { | |
597 | eeprom.usec_delay_step *= 2; | |
598 | eeprom.usec_delay_step--; | |
599 | ||
600 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
601 | { | |
602 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
603 | } | |
604 | } | |
605 | } | |
606 | else if (eeprom.adapt_state > 0) | |
607 | { | |
608 | /* To Low before (toggle dir) */ | |
609 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) | |
610 | { | |
611 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; | |
612 | } | |
613 | if (eeprom.usec_delay_step > 1) | |
614 | { | |
615 | eeprom.usec_delay_step /= 2; | |
616 | eeprom.usec_delay_step--; | |
617 | } | |
618 | ||
619 | eeprom.adapt_state = -1; | |
620 | } | |
621 | ||
622 | if (eeprom.adapt_state > -100) | |
623 | { | |
624 | eeprom.adapt_state--; | |
625 | } | |
626 | else | |
627 | { | |
628 | /* Restart adaption */ | |
629 | D(printk("#Restart\n")); | |
630 | eeprom.usec_delay_step++; | |
631 | } | |
632 | } | |
633 | #endif /* EEPROM_ADAPTIVE_TIMING */ | |
634 | /* write until we hit a page boundary or count */ | |
635 | do | |
636 | { | |
637 | i2c_outbyte(buf[written]); | |
638 | if(!i2c_getack()) | |
639 | { | |
640 | restart=1; | |
641 | printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i); | |
642 | i2c_stop(); | |
643 | break; | |
644 | } | |
645 | written++; | |
646 | p++; | |
647 | } while( written < count && ( p % eeprom.sequential_write_pagesize )); | |
648 | ||
649 | /* end write cycle */ | |
650 | i2c_stop(); | |
651 | i2c_delay(eeprom.usec_delay_writecycles); | |
652 | } /* while */ | |
653 | } /* for */ | |
654 | ||
4f0447b8 | 655 | mutex_unlock(&eeprom.lock); |
82f3952c | 656 | if (written == 0 && p >= eeprom.size){ |
1da177e4 LT |
657 | return -ENOSPC; |
658 | } | |
82f3952c | 659 | *off = p; |
1da177e4 LT |
660 | return written; |
661 | } | |
662 | ||
663 | /* Closes the device. */ | |
664 | ||
665 | static int eeprom_close(struct inode * inode, struct file * file) | |
666 | { | |
667 | /* do nothing for now */ | |
668 | return 0; | |
669 | } | |
670 | ||
671 | /* Sets the current address of the eeprom. */ | |
672 | ||
673 | static int eeprom_address(unsigned long addr) | |
674 | { | |
675 | int i; | |
676 | unsigned char page, offset; | |
677 | ||
678 | page = (unsigned char) (addr >> 8); | |
679 | offset = (unsigned char) addr; | |
680 | ||
681 | for(i = 0; i < EEPROM_RETRIES; i++) | |
682 | { | |
683 | /* start a dummy write for addressing */ | |
684 | i2c_start(); | |
685 | ||
686 | if(eeprom.size == EEPROM_16KB) | |
687 | { | |
688 | i2c_outbyte( eeprom.select_cmd ); | |
689 | i2c_getack(); | |
690 | i2c_outbyte(page); | |
691 | } | |
692 | else | |
693 | { | |
694 | i2c_outbyte( eeprom.select_cmd | (page << 1) ); | |
695 | } | |
696 | if(!i2c_getack()) | |
697 | { | |
698 | /* retry */ | |
699 | i2c_stop(); | |
700 | /* Must have a delay here.. 500 works, >50, 100->works 5th time*/ | |
701 | i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i); | |
702 | /* The chip needs up to 10 ms from write stop to next start */ | |
703 | ||
704 | } | |
705 | else | |
706 | { | |
707 | i2c_outbyte(offset); | |
708 | ||
709 | if(!i2c_getack()) | |
710 | { | |
711 | /* retry */ | |
712 | i2c_stop(); | |
713 | } | |
714 | else | |
715 | break; | |
716 | } | |
717 | } | |
718 | ||
719 | ||
720 | eeprom.retry_cnt_addr = i; | |
721 | D(printk("%i\n", eeprom.retry_cnt_addr)); | |
722 | if(eeprom.retry_cnt_addr == EEPROM_RETRIES) | |
723 | { | |
724 | /* failed */ | |
725 | return 0; | |
726 | } | |
727 | return 1; | |
728 | } | |
729 | ||
730 | /* Reads from current address. */ | |
731 | ||
732 | static int read_from_eeprom(char * buf, int count) | |
733 | { | |
734 | int i, read=0; | |
735 | ||
736 | for(i = 0; i < EEPROM_RETRIES; i++) | |
737 | { | |
738 | if(eeprom.size == EEPROM_16KB) | |
739 | { | |
740 | i2c_outbyte( eeprom.select_cmd | 1 ); | |
741 | } | |
742 | ||
743 | if(i2c_getack()) | |
744 | { | |
745 | break; | |
746 | } | |
747 | } | |
748 | ||
749 | if(i == EEPROM_RETRIES) | |
750 | { | |
751 | printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name); | |
752 | i2c_stop(); | |
753 | ||
754 | return -EFAULT; | |
755 | } | |
756 | ||
757 | while( (read < count)) | |
758 | { | |
759 | if (put_user(i2c_inbyte(), &buf[read++])) | |
760 | { | |
761 | i2c_stop(); | |
762 | ||
763 | return -EFAULT; | |
764 | } | |
765 | ||
766 | /* | |
767 | * make sure we don't ack last byte or you will get very strange | |
768 | * results! | |
769 | */ | |
770 | if(read < count) | |
771 | { | |
772 | i2c_sendack(); | |
773 | } | |
774 | } | |
775 | ||
776 | /* stop the operation */ | |
777 | i2c_stop(); | |
778 | ||
779 | return read; | |
780 | } | |
781 | ||
782 | /* Disables write protection if applicable. */ | |
783 | ||
784 | #define DBP_SAVE(x) | |
785 | #define ax_printf printk | |
786 | static void eeprom_disable_write_protect(void) | |
787 | { | |
788 | /* Disable write protect */ | |
789 | if (eeprom.size == EEPROM_8KB) | |
790 | { | |
791 | /* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */ | |
792 | i2c_start(); | |
793 | i2c_outbyte(0xbe); | |
794 | if(!i2c_getack()) | |
795 | { | |
796 | DBP_SAVE(ax_printf("Get ack returns false\n")); | |
797 | } | |
798 | i2c_outbyte(0xFF); | |
799 | if(!i2c_getack()) | |
800 | { | |
801 | DBP_SAVE(ax_printf("Get ack returns false 2\n")); | |
802 | } | |
803 | i2c_outbyte(0x02); | |
804 | if(!i2c_getack()) | |
805 | { | |
806 | DBP_SAVE(ax_printf("Get ack returns false 3\n")); | |
807 | } | |
808 | i2c_stop(); | |
809 | ||
810 | i2c_delay(1000); | |
811 | ||
812 | /* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */ | |
813 | i2c_start(); | |
814 | i2c_outbyte(0xbe); | |
815 | if(!i2c_getack()) | |
816 | { | |
817 | DBP_SAVE(ax_printf("Get ack returns false 55\n")); | |
818 | } | |
819 | i2c_outbyte(0xFF); | |
820 | if(!i2c_getack()) | |
821 | { | |
822 | DBP_SAVE(ax_printf("Get ack returns false 52\n")); | |
823 | } | |
824 | i2c_outbyte(0x06); | |
825 | if(!i2c_getack()) | |
826 | { | |
827 | DBP_SAVE(ax_printf("Get ack returns false 53\n")); | |
828 | } | |
829 | i2c_stop(); | |
830 | ||
831 | /* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */ | |
832 | i2c_start(); | |
833 | i2c_outbyte(0xbe); | |
834 | if(!i2c_getack()) | |
835 | { | |
836 | DBP_SAVE(ax_printf("Get ack returns false 56\n")); | |
837 | } | |
838 | i2c_outbyte(0xFF); | |
839 | if(!i2c_getack()) | |
840 | { | |
841 | DBP_SAVE(ax_printf("Get ack returns false 57\n")); | |
842 | } | |
843 | i2c_outbyte(0x06); | |
844 | if(!i2c_getack()) | |
845 | { | |
846 | DBP_SAVE(ax_printf("Get ack returns false 58\n")); | |
847 | } | |
848 | i2c_stop(); | |
849 | ||
850 | /* Write protect disabled */ | |
851 | } | |
852 | } | |
853 | ||
854 | module_init(eeprom_init); |