Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 $ |
Mikael Starvik | 7e92042 | 2005-07-27 11:44:34 -0700 | [diff] [blame] | 23 | *! Revision 1.12 2005/06/19 17:06:46 starvik |
| 24 | *! Merge of Linux 2.6.12. |
| 25 | *! |
| 26 | *! Revision 1.11 2005/01/26 07:14:46 starvik |
| 27 | *! Applied diff from kernel janitors (Nish Aravamudan). |
| 28 | *! |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | *! Revision 1.10 2003/09/11 07:29:48 starvik |
| 30 | *! Merge of Linux 2.6.0-test5 |
| 31 | *! |
| 32 | *! Revision 1.9 2003/07/04 08:27:37 starvik |
| 33 | *! Merge of Linux 2.5.74 |
| 34 | *! |
| 35 | *! Revision 1.8 2003/04/09 05:20:47 starvik |
| 36 | *! Merge of Linux 2.5.67 |
| 37 | *! |
| 38 | *! Revision 1.6 2003/02/10 07:19:28 starvik |
| 39 | *! Removed misplaced ; |
| 40 | *! |
| 41 | *! Revision 1.5 2002/12/11 13:13:57 starvik |
| 42 | *! Added arch/ to v10 specific includes |
| 43 | *! Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer) |
| 44 | *! |
| 45 | *! Revision 1.4 2002/11/20 11:56:10 starvik |
| 46 | *! Merge of Linux 2.5.48 |
| 47 | *! |
| 48 | *! Revision 1.3 2002/11/18 13:16:06 starvik |
| 49 | *! Linux 2.5 port of latest 2.4 drivers |
| 50 | *! |
| 51 | *! Revision 1.8 2001/06/15 13:24:29 jonashg |
| 52 | *! * Added verification of pointers from userspace in read and write. |
| 53 | *! * Made busy counter volatile. |
| 54 | *! * Added define for inital write delay. |
| 55 | *! * Removed warnings by using loff_t instead of unsigned long. |
| 56 | *! |
| 57 | *! Revision 1.7 2001/06/14 15:26:54 jonashg |
| 58 | *! Removed test because condition is always true. |
| 59 | *! |
| 60 | *! Revision 1.6 2001/06/14 15:18:20 jonashg |
| 61 | *! Kb -> kB (makes quite a difference if you don't know if you have 2k or 16k). |
| 62 | *! |
| 63 | *! Revision 1.5 2001/06/14 14:39:51 jonashg |
| 64 | *! Forgot to use name when registering the driver. |
| 65 | *! |
| 66 | *! Revision 1.4 2001/06/14 14:35:47 jonashg |
| 67 | *! * Gave driver a name and used it in printk's. |
| 68 | *! * Cleanup. |
| 69 | *! |
| 70 | *! Revision 1.3 2001/03/19 16:04:46 markusl |
| 71 | *! Fixed init of fops struct |
| 72 | *! |
| 73 | *! Revision 1.2 2001/03/19 10:35:07 markusl |
| 74 | *! 2.4 port of eeprom driver |
| 75 | *! |
| 76 | *! Revision 1.8 2000/05/18 10:42:25 edgar |
| 77 | *! Make sure to end write cycle on _every_ write |
| 78 | *! |
| 79 | *! Revision 1.7 2000/01/17 17:41:01 johana |
| 80 | *! Adjusted probing and return -ENOSPC when writing outside EEPROM |
| 81 | *! |
| 82 | *! Revision 1.6 2000/01/17 15:50:36 johana |
| 83 | *! Added adaptive timing adjustments and fixed autoprobing for 2k and 16k(?) |
| 84 | *! EEPROMs |
| 85 | *! |
| 86 | *! Revision 1.5 1999/09/03 15:07:37 edgar |
| 87 | *! Added bail-out check to the spinlock |
| 88 | *! |
| 89 | *! Revision 1.4 1999/09/03 12:11:17 bjornw |
| 90 | *! Proper atomicity (need to use spinlocks, not if's). users -> busy. |
| 91 | *! |
| 92 | *! |
| 93 | *! (c) 1999 Axis Communications AB, Lund, Sweden |
| 94 | *!*****************************************************************************/ |
| 95 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | #include <linux/kernel.h> |
| 97 | #include <linux/sched.h> |
| 98 | #include <linux/fs.h> |
| 99 | #include <linux/init.h> |
| 100 | #include <linux/delay.h> |
| 101 | #include <linux/interrupt.h> |
Mikael Starvik | 7e92042 | 2005-07-27 11:44:34 -0700 | [diff] [blame] | 102 | #include <linux/wait.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | #include <asm/uaccess.h> |
| 104 | #include "i2c.h" |
| 105 | |
| 106 | #define D(x) |
| 107 | |
| 108 | /* If we should use adaptive timing or not: */ |
| 109 | //#define EEPROM_ADAPTIVE_TIMING |
| 110 | |
| 111 | #define EEPROM_MAJOR_NR 122 /* use a LOCAL/EXPERIMENTAL major for now */ |
| 112 | #define EEPROM_MINOR_NR 0 |
| 113 | |
| 114 | /* Empirical sane initial value of the delay, the value will be adapted to |
| 115 | * what the chip needs when using EEPROM_ADAPTIVE_TIMING. |
| 116 | */ |
| 117 | #define INITIAL_WRITEDELAY_US 4000 |
| 118 | #define MAX_WRITEDELAY_US 10000 /* 10 ms according to spec for 2KB EEPROM */ |
| 119 | |
| 120 | /* This one defines how many times to try when eeprom fails. */ |
| 121 | #define EEPROM_RETRIES 10 |
| 122 | |
| 123 | #define EEPROM_2KB (2 * 1024) |
| 124 | /*#define EEPROM_4KB (4 * 1024)*/ /* Exists but not used in Axis products */ |
| 125 | #define EEPROM_8KB (8 * 1024 - 1 ) /* Last byte has write protection bit */ |
| 126 | #define EEPROM_16KB (16 * 1024) |
| 127 | |
| 128 | #define i2c_delay(x) udelay(x) |
| 129 | |
| 130 | /* |
| 131 | * This structure describes the attached eeprom chip. |
| 132 | * The values are probed for. |
| 133 | */ |
| 134 | |
| 135 | struct eeprom_type |
| 136 | { |
| 137 | unsigned long size; |
| 138 | unsigned long sequential_write_pagesize; |
| 139 | unsigned char select_cmd; |
| 140 | unsigned long usec_delay_writecycles; /* Min time between write cycles |
| 141 | (up to 10ms for some models) */ |
| 142 | unsigned long usec_delay_step; /* For adaptive algorithm */ |
| 143 | int adapt_state; /* 1 = To high , 0 = Even, -1 = To low */ |
| 144 | |
| 145 | /* this one is to keep the read/write operations atomic */ |
| 146 | wait_queue_head_t wait_q; |
| 147 | volatile int busy; |
| 148 | int retry_cnt_addr; /* Used to keep track of number of retries for |
| 149 | adaptive timing adjustments */ |
| 150 | int retry_cnt_read; |
| 151 | }; |
| 152 | |
| 153 | static int eeprom_open(struct inode * inode, struct file * file); |
| 154 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig); |
| 155 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, |
| 156 | loff_t *off); |
| 157 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, |
| 158 | loff_t *off); |
| 159 | static int eeprom_close(struct inode * inode, struct file * file); |
| 160 | |
| 161 | static int eeprom_address(unsigned long addr); |
| 162 | static int read_from_eeprom(char * buf, int count); |
| 163 | static int eeprom_write_buf(loff_t addr, const char * buf, int count); |
| 164 | static int eeprom_read_buf(loff_t addr, char * buf, int count); |
| 165 | |
| 166 | static void eeprom_disable_write_protect(void); |
| 167 | |
| 168 | |
| 169 | static const char eeprom_name[] = "eeprom"; |
| 170 | |
| 171 | /* chip description */ |
| 172 | static struct eeprom_type eeprom; |
| 173 | |
| 174 | /* This is the exported file-operations structure for this device. */ |
| 175 | struct file_operations eeprom_fops = |
| 176 | { |
| 177 | .llseek = eeprom_lseek, |
| 178 | .read = eeprom_read, |
| 179 | .write = eeprom_write, |
| 180 | .open = eeprom_open, |
| 181 | .release = eeprom_close |
| 182 | }; |
| 183 | |
| 184 | /* eeprom init call. Probes for different eeprom models. */ |
| 185 | |
| 186 | int __init eeprom_init(void) |
| 187 | { |
| 188 | init_waitqueue_head(&eeprom.wait_q); |
| 189 | eeprom.busy = 0; |
| 190 | |
| 191 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE |
| 192 | #define EETEXT "Found" |
| 193 | #else |
| 194 | #define EETEXT "Assuming" |
| 195 | #endif |
| 196 | if (register_chrdev(EEPROM_MAJOR_NR, eeprom_name, &eeprom_fops)) |
| 197 | { |
| 198 | printk(KERN_INFO "%s: unable to get major %d for eeprom device\n", |
| 199 | eeprom_name, EEPROM_MAJOR_NR); |
| 200 | return -1; |
| 201 | } |
| 202 | |
| 203 | printk("EEPROM char device v0.3, (c) 2000 Axis Communications AB\n"); |
| 204 | |
| 205 | /* |
| 206 | * Note: Most of this probing method was taken from the printserver (5470e) |
| 207 | * codebase. It did not contain a way of finding the 16kB chips |
| 208 | * (M24128 or variants). The method used here might not work |
| 209 | * for all models. If you encounter problems the easiest way |
| 210 | * is probably to define your model within #ifdef's, and hard- |
| 211 | * code it. |
| 212 | */ |
| 213 | |
| 214 | eeprom.size = 0; |
| 215 | eeprom.usec_delay_writecycles = INITIAL_WRITEDELAY_US; |
| 216 | eeprom.usec_delay_step = 128; |
| 217 | eeprom.adapt_state = 0; |
| 218 | |
| 219 | #ifdef CONFIG_ETRAX_I2C_EEPROM_PROBE |
| 220 | i2c_start(); |
| 221 | i2c_outbyte(0x80); |
| 222 | if(!i2c_getack()) |
| 223 | { |
| 224 | /* It's not 8k.. */ |
| 225 | int success = 0; |
| 226 | unsigned char buf_2k_start[16]; |
| 227 | |
| 228 | /* Im not sure this will work... :) */ |
| 229 | /* assume 2kB, if failure go for 16kB */ |
| 230 | /* Test with 16kB settings.. */ |
| 231 | /* If it's a 2kB EEPROM and we address it outside it's range |
| 232 | * it will mirror the address space: |
| 233 | * 1. We read two locations (that are mirrored), |
| 234 | * if the content differs * it's a 16kB EEPROM. |
| 235 | * 2. if it doesn't differ - write different value to one of the locations, |
| 236 | * check the other - if content still is the same it's a 2k EEPROM, |
| 237 | * restore original data. |
| 238 | */ |
| 239 | #define LOC1 8 |
| 240 | #define LOC2 (0x1fb) /*1fb, 3ed, 5df, 7d1 */ |
| 241 | |
| 242 | /* 2k settings */ |
| 243 | i2c_stop(); |
| 244 | eeprom.size = EEPROM_2KB; |
| 245 | eeprom.select_cmd = 0xA0; |
| 246 | eeprom.sequential_write_pagesize = 16; |
| 247 | if( eeprom_read_buf( 0, buf_2k_start, 16 ) == 16 ) |
| 248 | { |
| 249 | D(printk("2k start: '%16.16s'\n", buf_2k_start)); |
| 250 | } |
| 251 | else |
| 252 | { |
| 253 | printk(KERN_INFO "%s: Failed to read in 2k mode!\n", eeprom_name); |
| 254 | } |
| 255 | |
| 256 | /* 16k settings */ |
| 257 | eeprom.size = EEPROM_16KB; |
| 258 | eeprom.select_cmd = 0xA0; |
| 259 | eeprom.sequential_write_pagesize = 64; |
| 260 | |
| 261 | { |
| 262 | unsigned char loc1[4], loc2[4], tmp[4]; |
| 263 | if( eeprom_read_buf(LOC2, loc2, 4) == 4) |
| 264 | { |
| 265 | if( eeprom_read_buf(LOC1, loc1, 4) == 4) |
| 266 | { |
| 267 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", |
| 268 | LOC1, loc1, LOC2, loc2)); |
| 269 | #if 0 |
| 270 | if (memcmp(loc1, loc2, 4) != 0 ) |
| 271 | { |
| 272 | /* It's 16k */ |
| 273 | printk(KERN_INFO "%s: 16k detected in step 1\n", eeprom_name); |
| 274 | eeprom.size = EEPROM_16KB; |
| 275 | success = 1; |
| 276 | } |
| 277 | else |
| 278 | #endif |
| 279 | { |
| 280 | /* Do step 2 check */ |
| 281 | /* Invert value */ |
| 282 | loc1[0] = ~loc1[0]; |
| 283 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) |
| 284 | { |
| 285 | /* If 2k EEPROM this write will actually write 10 bytes |
| 286 | * from pos 0 |
| 287 | */ |
| 288 | D(printk("1 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", |
| 289 | LOC1, loc1, LOC2, loc2)); |
| 290 | if( eeprom_read_buf(LOC1, tmp, 4) == 4) |
| 291 | { |
| 292 | D(printk("2 loc1: (%i) '%4.4s' tmp '%4.4s'\n", |
| 293 | LOC1, loc1, tmp)); |
| 294 | if (memcmp(loc1, tmp, 4) != 0 ) |
| 295 | { |
| 296 | printk(KERN_INFO "%s: read and write differs! Not 16kB\n", |
| 297 | eeprom_name); |
| 298 | loc1[0] = ~loc1[0]; |
| 299 | |
| 300 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) |
| 301 | { |
| 302 | success = 1; |
| 303 | } |
| 304 | else |
| 305 | { |
| 306 | printk(KERN_INFO "%s: Restore 2k failed during probe," |
| 307 | " EEPROM might be corrupt!\n", eeprom_name); |
| 308 | |
| 309 | } |
| 310 | i2c_stop(); |
| 311 | /* Go to 2k mode and write original data */ |
| 312 | eeprom.size = EEPROM_2KB; |
| 313 | eeprom.select_cmd = 0xA0; |
| 314 | eeprom.sequential_write_pagesize = 16; |
| 315 | if( eeprom_write_buf(0, buf_2k_start, 16) == 16) |
| 316 | { |
| 317 | } |
| 318 | else |
| 319 | { |
| 320 | printk(KERN_INFO "%s: Failed to write back 2k start!\n", |
| 321 | eeprom_name); |
| 322 | } |
| 323 | |
| 324 | eeprom.size = EEPROM_2KB; |
| 325 | } |
| 326 | } |
| 327 | |
| 328 | if(!success) |
| 329 | { |
| 330 | if( eeprom_read_buf(LOC2, loc2, 1) == 1) |
| 331 | { |
| 332 | D(printk("0 loc1: (%i) '%4.4s' loc2 (%i) '%4.4s'\n", |
| 333 | LOC1, loc1, LOC2, loc2)); |
| 334 | if (memcmp(loc1, loc2, 4) == 0 ) |
| 335 | { |
| 336 | /* Data the same, must be mirrored -> 2k */ |
| 337 | /* Restore data */ |
| 338 | printk(KERN_INFO "%s: 2k detected in step 2\n", eeprom_name); |
| 339 | loc1[0] = ~loc1[0]; |
| 340 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) |
| 341 | { |
| 342 | success = 1; |
| 343 | } |
| 344 | else |
| 345 | { |
| 346 | printk(KERN_INFO "%s: Restore 2k failed during probe," |
| 347 | " EEPROM might be corrupt!\n", eeprom_name); |
| 348 | |
| 349 | } |
| 350 | |
| 351 | eeprom.size = EEPROM_2KB; |
| 352 | } |
| 353 | else |
| 354 | { |
| 355 | printk(KERN_INFO "%s: 16k detected in step 2\n", |
| 356 | eeprom_name); |
| 357 | loc1[0] = ~loc1[0]; |
| 358 | /* Data differs, assume 16k */ |
| 359 | /* Restore data */ |
| 360 | if (eeprom_write_buf(LOC1, loc1, 1) == 1) |
| 361 | { |
| 362 | success = 1; |
| 363 | } |
| 364 | else |
| 365 | { |
| 366 | printk(KERN_INFO "%s: Restore 16k failed during probe," |
| 367 | " EEPROM might be corrupt!\n", eeprom_name); |
| 368 | } |
| 369 | |
| 370 | eeprom.size = EEPROM_16KB; |
| 371 | } |
| 372 | } |
| 373 | } |
| 374 | } |
| 375 | } /* read LOC1 */ |
| 376 | } /* address LOC1 */ |
| 377 | if (!success) |
| 378 | { |
| 379 | printk(KERN_INFO "%s: Probing failed!, using 2KB!\n", eeprom_name); |
| 380 | eeprom.size = EEPROM_2KB; |
| 381 | } |
| 382 | } /* read */ |
| 383 | } |
| 384 | } |
| 385 | else |
| 386 | { |
| 387 | i2c_outbyte(0x00); |
| 388 | if(!i2c_getack()) |
| 389 | { |
| 390 | /* No 8k */ |
| 391 | eeprom.size = EEPROM_2KB; |
| 392 | } |
| 393 | else |
| 394 | { |
| 395 | i2c_start(); |
| 396 | i2c_outbyte(0x81); |
| 397 | if (!i2c_getack()) |
| 398 | { |
| 399 | eeprom.size = EEPROM_2KB; |
| 400 | } |
| 401 | else |
| 402 | { |
| 403 | /* It's a 8kB */ |
| 404 | i2c_inbyte(); |
| 405 | eeprom.size = EEPROM_8KB; |
| 406 | } |
| 407 | } |
| 408 | } |
| 409 | i2c_stop(); |
| 410 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_16KB) |
| 411 | eeprom.size = EEPROM_16KB; |
| 412 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_8KB) |
| 413 | eeprom.size = EEPROM_8KB; |
| 414 | #elif defined(CONFIG_ETRAX_I2C_EEPROM_2KB) |
| 415 | eeprom.size = EEPROM_2KB; |
| 416 | #endif |
| 417 | |
| 418 | switch(eeprom.size) |
| 419 | { |
| 420 | case (EEPROM_2KB): |
| 421 | printk("%s: " EETEXT " i2c compatible 2kB eeprom.\n", eeprom_name); |
| 422 | eeprom.sequential_write_pagesize = 16; |
| 423 | eeprom.select_cmd = 0xA0; |
| 424 | break; |
| 425 | case (EEPROM_8KB): |
| 426 | printk("%s: " EETEXT " i2c compatible 8kB eeprom.\n", eeprom_name); |
| 427 | eeprom.sequential_write_pagesize = 16; |
| 428 | eeprom.select_cmd = 0x80; |
| 429 | break; |
| 430 | case (EEPROM_16KB): |
| 431 | printk("%s: " EETEXT " i2c compatible 16kB eeprom.\n", eeprom_name); |
| 432 | eeprom.sequential_write_pagesize = 64; |
| 433 | eeprom.select_cmd = 0xA0; |
| 434 | break; |
| 435 | default: |
| 436 | eeprom.size = 0; |
| 437 | printk("%s: Did not find a supported eeprom\n", eeprom_name); |
| 438 | break; |
| 439 | } |
| 440 | |
| 441 | |
| 442 | |
| 443 | eeprom_disable_write_protect(); |
| 444 | |
| 445 | return 0; |
| 446 | } |
| 447 | |
| 448 | /* Opens the device. */ |
| 449 | |
| 450 | static int eeprom_open(struct inode * inode, struct file * file) |
| 451 | { |
| 452 | |
| 453 | if(MINOR(inode->i_rdev) != EEPROM_MINOR_NR) |
| 454 | return -ENXIO; |
| 455 | if(MAJOR(inode->i_rdev) != EEPROM_MAJOR_NR) |
| 456 | return -ENXIO; |
| 457 | |
| 458 | if( eeprom.size > 0 ) |
| 459 | { |
| 460 | /* OK */ |
| 461 | return 0; |
| 462 | } |
| 463 | |
| 464 | /* No EEprom found */ |
| 465 | return -EFAULT; |
| 466 | } |
| 467 | |
| 468 | /* Changes the current file position. */ |
| 469 | |
| 470 | static loff_t eeprom_lseek(struct file * file, loff_t offset, int orig) |
| 471 | { |
| 472 | /* |
| 473 | * orig 0: position from begning of eeprom |
| 474 | * orig 1: relative from current position |
| 475 | * orig 2: position from last eeprom address |
| 476 | */ |
| 477 | |
| 478 | switch (orig) |
| 479 | { |
| 480 | case 0: |
| 481 | file->f_pos = offset; |
| 482 | break; |
| 483 | case 1: |
| 484 | file->f_pos += offset; |
| 485 | break; |
| 486 | case 2: |
| 487 | file->f_pos = eeprom.size - offset; |
| 488 | break; |
| 489 | default: |
| 490 | return -EINVAL; |
| 491 | } |
| 492 | |
| 493 | /* truncate position */ |
| 494 | if (file->f_pos < 0) |
| 495 | { |
| 496 | file->f_pos = 0; |
| 497 | return(-EOVERFLOW); |
| 498 | } |
| 499 | |
| 500 | if (file->f_pos >= eeprom.size) |
| 501 | { |
| 502 | file->f_pos = eeprom.size - 1; |
| 503 | return(-EOVERFLOW); |
| 504 | } |
| 505 | |
| 506 | return ( file->f_pos ); |
| 507 | } |
| 508 | |
| 509 | /* Reads data from eeprom. */ |
| 510 | |
| 511 | static int eeprom_read_buf(loff_t addr, char * buf, int count) |
| 512 | { |
| 513 | struct file f; |
| 514 | |
| 515 | f.f_pos = addr; |
| 516 | return eeprom_read(&f, buf, count, &addr); |
| 517 | } |
| 518 | |
| 519 | |
| 520 | |
| 521 | /* Reads data from eeprom. */ |
| 522 | |
| 523 | static ssize_t eeprom_read(struct file * file, char * buf, size_t count, loff_t *off) |
| 524 | { |
| 525 | int read=0; |
| 526 | unsigned long p = file->f_pos; |
| 527 | |
| 528 | unsigned char page; |
| 529 | |
| 530 | if(p >= eeprom.size) /* Address i 0 - (size-1) */ |
| 531 | { |
| 532 | return -EFAULT; |
| 533 | } |
| 534 | |
Mikael Starvik | 7e92042 | 2005-07-27 11:44:34 -0700 | [diff] [blame] | 535 | wait_event_interruptible(eeprom.wait_q, !eeprom.busy); |
| 536 | if (signal_pending(current)) |
| 537 | return -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 538 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 539 | eeprom.busy++; |
| 540 | |
| 541 | page = (unsigned char) (p >> 8); |
| 542 | |
| 543 | if(!eeprom_address(p)) |
| 544 | { |
| 545 | printk(KERN_INFO "%s: Read failed to address the eeprom: " |
| 546 | "0x%08X (%i) page: %i\n", eeprom_name, (int)p, (int)p, page); |
| 547 | i2c_stop(); |
| 548 | |
| 549 | /* don't forget to wake them up */ |
| 550 | eeprom.busy--; |
| 551 | wake_up_interruptible(&eeprom.wait_q); |
| 552 | return -EFAULT; |
| 553 | } |
| 554 | |
| 555 | if( (p + count) > eeprom.size) |
| 556 | { |
| 557 | /* truncate count */ |
| 558 | count = eeprom.size - p; |
| 559 | } |
| 560 | |
| 561 | /* stop dummy write op and initiate the read op */ |
| 562 | i2c_start(); |
| 563 | |
| 564 | /* special case for small eeproms */ |
| 565 | if(eeprom.size < EEPROM_16KB) |
| 566 | { |
| 567 | i2c_outbyte( eeprom.select_cmd | 1 | (page << 1) ); |
| 568 | } |
| 569 | |
| 570 | /* go on with the actual read */ |
| 571 | read = read_from_eeprom( buf, count); |
| 572 | |
| 573 | if(read > 0) |
| 574 | { |
| 575 | file->f_pos += read; |
| 576 | } |
| 577 | |
| 578 | eeprom.busy--; |
| 579 | wake_up_interruptible(&eeprom.wait_q); |
| 580 | return read; |
| 581 | } |
| 582 | |
| 583 | /* Writes data to eeprom. */ |
| 584 | |
| 585 | static int eeprom_write_buf(loff_t addr, const char * buf, int count) |
| 586 | { |
| 587 | struct file f; |
| 588 | |
| 589 | f.f_pos = addr; |
| 590 | |
| 591 | return eeprom_write(&f, buf, count, &addr); |
| 592 | } |
| 593 | |
| 594 | |
| 595 | /* Writes data to eeprom. */ |
| 596 | |
| 597 | static ssize_t eeprom_write(struct file * file, const char * buf, size_t count, |
| 598 | loff_t *off) |
| 599 | { |
| 600 | int i, written, restart=1; |
| 601 | unsigned long p; |
| 602 | |
| 603 | if (!access_ok(VERIFY_READ, buf, count)) |
| 604 | { |
| 605 | return -EFAULT; |
| 606 | } |
| 607 | |
Mikael Starvik | 7e92042 | 2005-07-27 11:44:34 -0700 | [diff] [blame] | 608 | wait_event_interruptible(eeprom.wait_q, !eeprom.busy); |
| 609 | /* bail out if we get interrupted */ |
| 610 | if (signal_pending(current)) |
| 611 | return -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | eeprom.busy++; |
| 613 | for(i = 0; (i < EEPROM_RETRIES) && (restart > 0); i++) |
| 614 | { |
| 615 | restart = 0; |
| 616 | written = 0; |
| 617 | p = file->f_pos; |
| 618 | |
| 619 | |
| 620 | while( (written < count) && (p < eeprom.size)) |
| 621 | { |
| 622 | /* address the eeprom */ |
| 623 | if(!eeprom_address(p)) |
| 624 | { |
| 625 | printk(KERN_INFO "%s: Write failed to address the eeprom: " |
| 626 | "0x%08X (%i) \n", eeprom_name, (int)p, (int)p); |
| 627 | i2c_stop(); |
| 628 | |
| 629 | /* don't forget to wake them up */ |
| 630 | eeprom.busy--; |
| 631 | wake_up_interruptible(&eeprom.wait_q); |
| 632 | return -EFAULT; |
| 633 | } |
| 634 | #ifdef EEPROM_ADAPTIVE_TIMING |
| 635 | /* Adaptive algorithm to adjust timing */ |
| 636 | if (eeprom.retry_cnt_addr > 0) |
| 637 | { |
| 638 | /* To Low now */ |
| 639 | D(printk(">D=%i d=%i\n", |
| 640 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); |
| 641 | |
| 642 | if (eeprom.usec_delay_step < 4) |
| 643 | { |
| 644 | eeprom.usec_delay_step++; |
| 645 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; |
| 646 | } |
| 647 | else |
| 648 | { |
| 649 | |
| 650 | if (eeprom.adapt_state > 0) |
| 651 | { |
| 652 | /* To Low before */ |
| 653 | eeprom.usec_delay_step *= 2; |
| 654 | if (eeprom.usec_delay_step > 2) |
| 655 | { |
| 656 | eeprom.usec_delay_step--; |
| 657 | } |
| 658 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; |
| 659 | } |
| 660 | else if (eeprom.adapt_state < 0) |
| 661 | { |
| 662 | /* To High before (toggle dir) */ |
| 663 | eeprom.usec_delay_writecycles += eeprom.usec_delay_step; |
| 664 | if (eeprom.usec_delay_step > 1) |
| 665 | { |
| 666 | eeprom.usec_delay_step /= 2; |
| 667 | eeprom.usec_delay_step--; |
| 668 | } |
| 669 | } |
| 670 | } |
| 671 | |
| 672 | eeprom.adapt_state = 1; |
| 673 | } |
| 674 | else |
| 675 | { |
| 676 | /* To High (or good) now */ |
| 677 | D(printk("<D=%i d=%i\n", |
| 678 | eeprom.usec_delay_writecycles, eeprom.usec_delay_step)); |
| 679 | |
| 680 | if (eeprom.adapt_state < 0) |
| 681 | { |
| 682 | /* To High before */ |
| 683 | if (eeprom.usec_delay_step > 1) |
| 684 | { |
| 685 | eeprom.usec_delay_step *= 2; |
| 686 | eeprom.usec_delay_step--; |
| 687 | |
| 688 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) |
| 689 | { |
| 690 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; |
| 691 | } |
| 692 | } |
| 693 | } |
| 694 | else if (eeprom.adapt_state > 0) |
| 695 | { |
| 696 | /* To Low before (toggle dir) */ |
| 697 | if (eeprom.usec_delay_writecycles > eeprom.usec_delay_step) |
| 698 | { |
| 699 | eeprom.usec_delay_writecycles -= eeprom.usec_delay_step; |
| 700 | } |
| 701 | if (eeprom.usec_delay_step > 1) |
| 702 | { |
| 703 | eeprom.usec_delay_step /= 2; |
| 704 | eeprom.usec_delay_step--; |
| 705 | } |
| 706 | |
| 707 | eeprom.adapt_state = -1; |
| 708 | } |
| 709 | |
| 710 | if (eeprom.adapt_state > -100) |
| 711 | { |
| 712 | eeprom.adapt_state--; |
| 713 | } |
| 714 | else |
| 715 | { |
| 716 | /* Restart adaption */ |
| 717 | D(printk("#Restart\n")); |
| 718 | eeprom.usec_delay_step++; |
| 719 | } |
| 720 | } |
| 721 | #endif /* EEPROM_ADAPTIVE_TIMING */ |
| 722 | /* write until we hit a page boundary or count */ |
| 723 | do |
| 724 | { |
| 725 | i2c_outbyte(buf[written]); |
| 726 | if(!i2c_getack()) |
| 727 | { |
| 728 | restart=1; |
| 729 | printk(KERN_INFO "%s: write error, retrying. %d\n", eeprom_name, i); |
| 730 | i2c_stop(); |
| 731 | break; |
| 732 | } |
| 733 | written++; |
| 734 | p++; |
| 735 | } while( written < count && ( p % eeprom.sequential_write_pagesize )); |
| 736 | |
| 737 | /* end write cycle */ |
| 738 | i2c_stop(); |
| 739 | i2c_delay(eeprom.usec_delay_writecycles); |
| 740 | } /* while */ |
| 741 | } /* for */ |
| 742 | |
| 743 | eeprom.busy--; |
| 744 | wake_up_interruptible(&eeprom.wait_q); |
| 745 | if (written == 0 && file->f_pos >= eeprom.size){ |
| 746 | return -ENOSPC; |
| 747 | } |
| 748 | file->f_pos += written; |
| 749 | return written; |
| 750 | } |
| 751 | |
| 752 | /* Closes the device. */ |
| 753 | |
| 754 | static int eeprom_close(struct inode * inode, struct file * file) |
| 755 | { |
| 756 | /* do nothing for now */ |
| 757 | return 0; |
| 758 | } |
| 759 | |
| 760 | /* Sets the current address of the eeprom. */ |
| 761 | |
| 762 | static int eeprom_address(unsigned long addr) |
| 763 | { |
| 764 | int i; |
| 765 | unsigned char page, offset; |
| 766 | |
| 767 | page = (unsigned char) (addr >> 8); |
| 768 | offset = (unsigned char) addr; |
| 769 | |
| 770 | for(i = 0; i < EEPROM_RETRIES; i++) |
| 771 | { |
| 772 | /* start a dummy write for addressing */ |
| 773 | i2c_start(); |
| 774 | |
| 775 | if(eeprom.size == EEPROM_16KB) |
| 776 | { |
| 777 | i2c_outbyte( eeprom.select_cmd ); |
| 778 | i2c_getack(); |
| 779 | i2c_outbyte(page); |
| 780 | } |
| 781 | else |
| 782 | { |
| 783 | i2c_outbyte( eeprom.select_cmd | (page << 1) ); |
| 784 | } |
| 785 | if(!i2c_getack()) |
| 786 | { |
| 787 | /* retry */ |
| 788 | i2c_stop(); |
| 789 | /* Must have a delay here.. 500 works, >50, 100->works 5th time*/ |
| 790 | i2c_delay(MAX_WRITEDELAY_US / EEPROM_RETRIES * i); |
| 791 | /* The chip needs up to 10 ms from write stop to next start */ |
| 792 | |
| 793 | } |
| 794 | else |
| 795 | { |
| 796 | i2c_outbyte(offset); |
| 797 | |
| 798 | if(!i2c_getack()) |
| 799 | { |
| 800 | /* retry */ |
| 801 | i2c_stop(); |
| 802 | } |
| 803 | else |
| 804 | break; |
| 805 | } |
| 806 | } |
| 807 | |
| 808 | |
| 809 | eeprom.retry_cnt_addr = i; |
| 810 | D(printk("%i\n", eeprom.retry_cnt_addr)); |
| 811 | if(eeprom.retry_cnt_addr == EEPROM_RETRIES) |
| 812 | { |
| 813 | /* failed */ |
| 814 | return 0; |
| 815 | } |
| 816 | return 1; |
| 817 | } |
| 818 | |
| 819 | /* Reads from current address. */ |
| 820 | |
| 821 | static int read_from_eeprom(char * buf, int count) |
| 822 | { |
| 823 | int i, read=0; |
| 824 | |
| 825 | for(i = 0; i < EEPROM_RETRIES; i++) |
| 826 | { |
| 827 | if(eeprom.size == EEPROM_16KB) |
| 828 | { |
| 829 | i2c_outbyte( eeprom.select_cmd | 1 ); |
| 830 | } |
| 831 | |
| 832 | if(i2c_getack()) |
| 833 | { |
| 834 | break; |
| 835 | } |
| 836 | } |
| 837 | |
| 838 | if(i == EEPROM_RETRIES) |
| 839 | { |
| 840 | printk(KERN_INFO "%s: failed to read from eeprom\n", eeprom_name); |
| 841 | i2c_stop(); |
| 842 | |
| 843 | return -EFAULT; |
| 844 | } |
| 845 | |
| 846 | while( (read < count)) |
| 847 | { |
| 848 | if (put_user(i2c_inbyte(), &buf[read++])) |
| 849 | { |
| 850 | i2c_stop(); |
| 851 | |
| 852 | return -EFAULT; |
| 853 | } |
| 854 | |
| 855 | /* |
| 856 | * make sure we don't ack last byte or you will get very strange |
| 857 | * results! |
| 858 | */ |
| 859 | if(read < count) |
| 860 | { |
| 861 | i2c_sendack(); |
| 862 | } |
| 863 | } |
| 864 | |
| 865 | /* stop the operation */ |
| 866 | i2c_stop(); |
| 867 | |
| 868 | return read; |
| 869 | } |
| 870 | |
| 871 | /* Disables write protection if applicable. */ |
| 872 | |
| 873 | #define DBP_SAVE(x) |
| 874 | #define ax_printf printk |
| 875 | static void eeprom_disable_write_protect(void) |
| 876 | { |
| 877 | /* Disable write protect */ |
| 878 | if (eeprom.size == EEPROM_8KB) |
| 879 | { |
| 880 | /* Step 1 Set WEL = 1 (write 00000010 to address 1FFFh */ |
| 881 | i2c_start(); |
| 882 | i2c_outbyte(0xbe); |
| 883 | if(!i2c_getack()) |
| 884 | { |
| 885 | DBP_SAVE(ax_printf("Get ack returns false\n")); |
| 886 | } |
| 887 | i2c_outbyte(0xFF); |
| 888 | if(!i2c_getack()) |
| 889 | { |
| 890 | DBP_SAVE(ax_printf("Get ack returns false 2\n")); |
| 891 | } |
| 892 | i2c_outbyte(0x02); |
| 893 | if(!i2c_getack()) |
| 894 | { |
| 895 | DBP_SAVE(ax_printf("Get ack returns false 3\n")); |
| 896 | } |
| 897 | i2c_stop(); |
| 898 | |
| 899 | i2c_delay(1000); |
| 900 | |
| 901 | /* Step 2 Set RWEL = 1 (write 00000110 to address 1FFFh */ |
| 902 | i2c_start(); |
| 903 | i2c_outbyte(0xbe); |
| 904 | if(!i2c_getack()) |
| 905 | { |
| 906 | DBP_SAVE(ax_printf("Get ack returns false 55\n")); |
| 907 | } |
| 908 | i2c_outbyte(0xFF); |
| 909 | if(!i2c_getack()) |
| 910 | { |
| 911 | DBP_SAVE(ax_printf("Get ack returns false 52\n")); |
| 912 | } |
| 913 | i2c_outbyte(0x06); |
| 914 | if(!i2c_getack()) |
| 915 | { |
| 916 | DBP_SAVE(ax_printf("Get ack returns false 53\n")); |
| 917 | } |
| 918 | i2c_stop(); |
| 919 | |
| 920 | /* Step 3 Set BP1, BP0, and/or WPEN bits (write 00000110 to address 1FFFh */ |
| 921 | i2c_start(); |
| 922 | i2c_outbyte(0xbe); |
| 923 | if(!i2c_getack()) |
| 924 | { |
| 925 | DBP_SAVE(ax_printf("Get ack returns false 56\n")); |
| 926 | } |
| 927 | i2c_outbyte(0xFF); |
| 928 | if(!i2c_getack()) |
| 929 | { |
| 930 | DBP_SAVE(ax_printf("Get ack returns false 57\n")); |
| 931 | } |
| 932 | i2c_outbyte(0x06); |
| 933 | if(!i2c_getack()) |
| 934 | { |
| 935 | DBP_SAVE(ax_printf("Get ack returns false 58\n")); |
| 936 | } |
| 937 | i2c_stop(); |
| 938 | |
| 939 | /* Write protect disabled */ |
| 940 | } |
| 941 | } |
| 942 | |
| 943 | module_init(eeprom_init); |