drivers/char/nwflash.c

   1 /*
   2  * Flash memory interface rev.5 driver for the Intel
   3  * Flash chips used on the NetWinder.
   4  *
   5  * 20/08/2000   RMK     use __ioremap to map flash into virtual memory
   6  *                      make a few more places use "volatile"
   7  * 22/05/2001   RMK     - Lock read against write
   8  *                      - merge printk level changes (with mods) from Alan Cox.
   9  *                      - use *ppos as the file position, not file->f_pos.
  10  *                      - fix check for out of range pos and r/w size
  11  *
  12  * Please note that we are tampering with the only flash chip in the
  13  * machine, which contains the bootup code.  We therefore have the
  14  * power to convert these machines into doorstops...
  15  */
  16
  17 #include <linux/module.h>
  18 #include <linux/types.h>
  19 #include <linux/fs.h>
  20 #include <linux/errno.h>
  21 #include <linux/mm.h>
  22 #include <linux/delay.h>
  23 #include <linux/proc_fs.h>
  24 #include <linux/sched.h>
  25 #include <linux/miscdevice.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/rwsem.h>
  28 #include <linux/init.h>
  29 #include <linux/smp_lock.h>
  30
  31 #include <asm/hardware/dec21285.h>
  32 #include <asm/io.h>
  33 #include <asm/leds.h>
  34 #include <asm/mach-types.h>
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37
  38 /*****************************************************************************/
  39 #include <asm/nwflash.h>
  40
  41 #define NWFLASH_VERSION "6.4"
  42
  43 static void kick_open(void);
  44 static int get_flash_id(void);
  45 static int erase_block(int nBlock);
  46 static int write_block(unsigned long p, const char *buf, int count);
  47 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg);
  48 static ssize_t flash_read(struct file *file, char *buf, size_t count, loff_t * ppos);
  49 static ssize_t flash_write(struct file *file, const char *buf, size_t count, loff_t * ppos);
  50 static loff_t flash_llseek(struct file *file, loff_t offset, int orig);
  51
  52 #define KFLASH_SIZE     1024*1024       //1 Meg
  53 #define KFLASH_SIZE4    4*1024*1024     //4 Meg
  54 #define KFLASH_ID       0x89A6          //Intel flash
  55 #define KFLASH_ID4      0xB0D4          //Intel flash 4Meg
  56
  57 static int flashdebug;          //if set - we will display progress msgs
  58
  59 static int gbWriteEnable;
  60 static int gbWriteBase64Enable;
  61 static volatile unsigned char *FLASH_BASE;
  62 static int gbFlashSize = KFLASH_SIZE;
  63 static DECLARE_MUTEX(nwflash_sem);
  64
  65 extern spinlock_t gpio_lock;
  66
  67 /*
  68  * the delay routine - it is often required to let the flash "breeze"...
  69  */
  70 void flash_wait(int timeout)
  71 {
  72         current->state = TASK_INTERRUPTIBLE;
  73         schedule_timeout(timeout);
  74 }
  75
  76 static int get_flash_id(void)
  77 {
  78         volatile unsigned int c1, c2;
  79
  80         /*
  81          * try to get flash chip ID
  82          */
  83         kick_open();
  84         c2 = inb(0x80);
  85         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
  86         udelay(15);
  87         c1 = *(volatile unsigned char *) FLASH_BASE;
  88         c2 = inb(0x80);
  89
  90         /*
  91          * on 4 Meg flash the second byte is actually at offset 2...
  92          */
  93         if (c1 == 0xB0)
  94                 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
  95         else
  96                 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
  97
  98         c2 += (c1 << 8);
  99
 100         /*
 101          * set it back to read mode
 102          */
 103         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 104
 105         if (c2 == KFLASH_ID4)
 106                 gbFlashSize = KFLASH_SIZE4;
 107
 108         return c2;
 109 }
 110
 111 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg)
 112 {
 113         switch (cmd) {
 114         case CMD_WRITE_DISABLE:
 115                 gbWriteBase64Enable = 0;
 116                 gbWriteEnable = 0;
 117                 break;
 118
 119         case CMD_WRITE_ENABLE:
 120                 gbWriteEnable = 1;
 121                 break;
 122
 123         case CMD_WRITE_BASE64K_ENABLE:
 124                 gbWriteBase64Enable = 1;
 125                 break;
 126
 127         default:
 128                 gbWriteBase64Enable = 0;
 129                 gbWriteEnable = 0;
 130                 return -EINVAL;
 131         }
 132         return 0;
 133 }
 134
 135 static ssize_t flash_read(struct file *file, char *buf, size_t size, loff_t * ppos)
 136 {
 137         unsigned long p = *ppos;
 138         unsigned int count = size;
 139         int ret = 0;
 140
 141         if (flashdebug)
 142                 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%lX, buffer=%p, count=0x%X.\n",
 143                        p, buf, count);
 144
 145         if (count)
 146                 ret = -ENXIO;
 147
 148         if (p < gbFlashSize) {
 149                 if (count > gbFlashSize - p)
 150                         count = gbFlashSize - p;
 151
 152                 /*
 153                  * We now lock against reads and writes. --rmk
 154                  */
 155                 if (down_interruptible(&nwflash_sem))
 156                         return -ERESTARTSYS;
 157
 158                 ret = copy_to_user(buf, (void *)(FLASH_BASE + p), count);
 159                 if (ret == 0) {
 160                         ret = count;
 161                         *ppos += count;
 162                 } else
 163                         ret = -EFAULT;
 164                 up(&nwflash_sem);
 165         }
 166         return ret;
 167 }
 168
 169 static ssize_t flash_write(struct file *file, const char *buf, size_t size, loff_t * ppos)
 170 {
 171         unsigned long p = *ppos;
 172         unsigned int count = size;
 173         int written;
 174         int nBlock, temp, rc;
 175         int i, j;
 176
 177         if (flashdebug)
 178                 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
 179                        p, buf, count);
 180
 181         if (!gbWriteEnable)
 182                 return -EINVAL;
 183
 184         if (p < 64 * 1024 && (!gbWriteBase64Enable))
 185                 return -EINVAL;
 186
 187         /*
 188          * check for out of range pos or count
 189          */
 190         if (p >= gbFlashSize)
 191                 return count ? -ENXIO : 0;
 192
 193         if (count > gbFlashSize - p)
 194                 count = gbFlashSize - p;
 195
 196         if (verify_area(VERIFY_READ, buf, count))
 197                 return -EFAULT;
 198
 199         /*
 200          * We now lock against reads and writes. --rmk
 201          */
 202         if (down_interruptible(&nwflash_sem))
 203                 return -ERESTARTSYS;
 204
 205         written = 0;
 206
 207         leds_event(led_claim);
 208         leds_event(led_green_on);
 209
 210         nBlock = (int) p >> 16; //block # of 64K bytes
 211
 212         /*
 213          * # of 64K blocks to erase and write
 214          */
 215         temp = ((int) (p + count) >> 16) - nBlock + 1;
 216
 217         /*
 218          * write ends at exactly 64k boundary?
 219          */
 220         if (((int) (p + count) & 0xFFFF) == 0)
 221                 temp -= 1;
 222
 223         if (flashdebug)
 224                 printk(KERN_DEBUG "flash_write: writing %d block(s) "
 225                         "starting at %d.\n", temp, nBlock);
 226
 227         for (; temp; temp--, nBlock++) {
 228                 if (flashdebug)
 229                         printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
 230
 231                 /*
 232                  * first we have to erase the block(s), where we will write...
 233                  */
 234                 i = 0;
 235                 j = 0;
 236           RetryBlock:
 237                 do {
 238                         rc = erase_block(nBlock);
 239                         i++;
 240                 } while (rc && i < 10);
 241
 242                 if (rc) {
 243                         printk(KERN_ERR "flash_write: erase error %x\n", rc);
 244                         break;
 245                 }
 246                 if (flashdebug)
 247                         printk(KERN_DEBUG "flash_write: writing offset %lX, from buf "
 248                                 "%p, bytes left %X.\n", p, buf, count - written);
 249
 250                 /*
 251                  * write_block will limit write to space left in this block
 252                  */
 253                 rc = write_block(p, buf, count - written);
 254                 j++;
 255
 256                 /*
 257                  * if somehow write verify failed? Can't happen??
 258                  */
 259                 if (!rc) {
 260                         /*
 261                          * retry up to 10 times
 262                          */
 263                         if (j < 10)
 264                                 goto RetryBlock;
 265                         else
 266                                 /*
 267                                  * else quit with error...
 268                                  */
 269                                 rc = -1;
 270
 271                 }
 272                 if (rc < 0) {
 273                         printk(KERN_ERR "flash_write: write error %X\n", rc);
 274                         break;
 275                 }
 276                 p += rc;
 277                 buf += rc;
 278                 written += rc;
 279                 *ppos += rc;
 280
 281                 if (flashdebug)
 282                         printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
 283         }
 284
 285         /*
 286          * restore reg on exit
 287          */
 288         leds_event(led_release);
 289
 290         up(&nwflash_sem);
 291
 292         return written;
 293 }
 294
 295
 296 /*
 297  * The memory devices use the full 32/64 bits of the offset, and so we cannot
 298  * check against negative addresses: they are ok. The return value is weird,
 299  * though, in that case (0).
 300  *
 301  * also note that seeking relative to the "end of file" isn't supported:
 302  * it has no meaning, so it returns -EINVAL.
 303  */
 304 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
 305 {
 306         loff_t ret;
 307
 308         lock_kernel();
 309         if (flashdebug)
 310                 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
 311                        (unsigned int) offset, orig);
 312
 313         switch (orig) {
 314         case 0:
 315                 if (offset < 0) {
 316                         ret = -EINVAL;
 317                         break;
 318                 }
 319
 320                 if ((unsigned int) offset > gbFlashSize) {
 321                         ret = -EINVAL;
 322                         break;
 323                 }
 324
 325                 file->f_pos = (unsigned int) offset;
 326                 ret = file->f_pos;
 327                 break;
 328         case 1:
 329                 if ((file->f_pos + offset) > gbFlashSize) {
 330                         ret = -EINVAL;
 331                         break;
 332                 }
 333                 if ((file->f_pos + offset) < 0) {
 334                         ret = -EINVAL;
 335                         break;
 336                 }
 337                 file->f_pos += offset;
 338                 ret = file->f_pos;
 339                 break;
 340         default:
 341                 ret = -EINVAL;
 342         }
 343         unlock_kernel();
 344         return ret;
 345 }
 346
 347
 348 /*
 349  * assume that main Write routine did the parameter checking...
 350  * so just go ahead and erase, what requested!
 351  */
 352
 353 static int erase_block(int nBlock)
 354 {
 355         volatile unsigned int c1;
 356         volatile unsigned char *pWritePtr;
 357         unsigned long timeout;
 358         int temp, temp1;
 359
 360         /*
 361          * orange LED == erase
 362          */
 363         leds_event(led_amber_on);
 364
 365         /*
 366          * reset footbridge to the correct offset 0 (...0..3)
 367          */
 368         *CSR_ROMWRITEREG = 0;
 369
 370         /*
 371          * dummy ROM read
 372          */
 373         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 374
 375         kick_open();
 376         /*
 377          * reset status if old errors
 378          */
 379         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 380
 381         /*
 382          * erase a block...
 383          * aim at the middle of a current block...
 384          */
 385         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
 386         /*
 387          * dummy read
 388          */
 389         c1 = *pWritePtr;
 390
 391         kick_open();
 392         /*
 393          * erase
 394          */
 395         *(volatile unsigned char *) pWritePtr = 0x20;
 396
 397         /*
 398          * confirm
 399          */
 400         *(volatile unsigned char *) pWritePtr = 0xD0;
 401
 402         /*
 403          * wait 10 ms
 404          */
 405         flash_wait(HZ / 100);
 406
 407         /*
 408          * wait while erasing in process (up to 10 sec)
 409          */
 410         timeout = jiffies + 10 * HZ;
 411         c1 = 0;
 412         while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
 413                 flash_wait(HZ / 100);
 414                 /*
 415                  * read any address
 416                  */
 417                 c1 = *(volatile unsigned char *) (pWritePtr);
 418                 //              printk("Flash_erase: status=%X.\n",c1);
 419         }
 420
 421         /*
 422          * set flash for normal read access
 423          */
 424         kick_open();
 425 //      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
 426         *(volatile unsigned char *) pWritePtr = 0xFF;   //back to normal operation
 427
 428         /*
 429          * check if erase errors were reported
 430          */
 431         if (c1 & 0x20) {
 432                 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
 433
 434                 /*
 435                  * reset error
 436                  */
 437                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 438                 return -2;
 439         }
 440
 441         /*
 442          * just to make sure - verify if erased OK...
 443          */
 444         flash_wait(HZ / 100);
 445
 446         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
 447
 448         for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
 449                 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
 450                         printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
 451                                pWritePtr, temp1);
 452                         return -1;
 453                 }
 454         }
 455
 456         return 0;
 457
 458 }
 459
 460 /*
 461  * write_block will limit number of bytes written to the space in this block
 462  */
 463 static int write_block(unsigned long p, const char *buf, int count)
 464 {
 465         volatile unsigned int c1;
 466         volatile unsigned int c2;
 467         unsigned char *pWritePtr;
 468         unsigned int uAddress;
 469         unsigned int offset;
 470         unsigned long timeout;
 471         unsigned long timeout1;
 472
 473         /*
 474          * red LED == write
 475          */
 476         leds_event(led_amber_off);
 477         leds_event(led_red_on);
 478
 479         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 480
 481         /*
 482          * check if write will end in this block....
 483          */
 484         offset = p & 0xFFFF;
 485
 486         if (offset + count > 0x10000)
 487                 count = 0x10000 - offset;
 488
 489         /*
 490          * wait up to 30 sec for this block
 491          */
 492         timeout = jiffies + 30 * HZ;
 493
 494         for (offset = 0; offset < count; offset++, pWritePtr++) {
 495                 uAddress = (unsigned int) pWritePtr;
 496                 uAddress &= 0xFFFFFFFC;
 497                 if (__get_user(c2, buf + offset))
 498                         return -EFAULT;
 499
 500           WriteRetry:
 501                 /*
 502                  * dummy read
 503                  */
 504                 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 505
 506                 /*
 507                  * kick open the write gate
 508                  */
 509                 kick_open();
 510
 511                 /*
 512                  * program footbridge to the correct offset...0..3
 513                  */
 514                 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
 515
 516                 /*
 517                  * write cmd
 518                  */
 519                 *(volatile unsigned char *) (uAddress) = 0x40;
 520
 521                 /*
 522                  * data to write
 523                  */
 524                 *(volatile unsigned char *) (uAddress) = c2;
 525
 526                 /*
 527                  * get status
 528                  */
 529                 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
 530
 531                 c1 = 0;
 532
 533                 /*
 534                  * wait up to 1 sec for this byte
 535                  */
 536                 timeout1 = jiffies + 1 * HZ;
 537
 538                 /*
 539                  * while not ready...
 540                  */
 541                 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
 542                         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 543
 544                 /*
 545                  * if timeout getting status
 546                  */
 547                 if (time_after_eq(jiffies, timeout1)) {
 548                         kick_open();
 549                         /*
 550                          * reset err
 551                          */
 552                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 553
 554                         goto WriteRetry;
 555                 }
 556                 /*
 557                  * switch on read access, as a default flash operation mode
 558                  */
 559                 kick_open();
 560                 /*
 561                  * read access
 562                  */
 563                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 564
 565                 /*
 566                  * if hardware reports an error writing, and not timeout -
 567                  * reset the chip and retry
 568                  */
 569                 if (c1 & 0x10) {
 570                         kick_open();
 571                         /*
 572                          * reset err
 573                          */
 574                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 575
 576                         /*
 577                          * before timeout?
 578                          */
 579                         if (time_before(jiffies, timeout)) {
 580                                 if (flashdebug)
 581                                         printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
 582                                                pWritePtr - FLASH_BASE);
 583
 584                                 /*
 585                                  * no LED == waiting
 586                                  */
 587                                 leds_event(led_amber_off);
 588                                 /*
 589                                  * wait couple ms
 590                                  */
 591                                 flash_wait(HZ / 100);
 592                                 /*
 593                                  * red LED == write
 594                                  */
 595                                 leds_event(led_red_on);
 596
 597                                 goto WriteRetry;
 598                         } else {
 599                                 printk(KERN_ERR "write_block: timeout at 0x%X\n",
 600                                        pWritePtr - FLASH_BASE);
 601                                 /*
 602                                  * return error -2
 603                                  */
 604                                 return -2;
 605
 606                         }
 607                 }
 608         }
 609
 610         /*
 611          * green LED == read/verify
 612          */
 613         leds_event(led_amber_off);
 614         leds_event(led_green_on);
 615
 616         flash_wait(HZ / 100);
 617
 618         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 619
 620         for (offset = 0; offset < count; offset++) {
 621                 char c, c1;
 622                 if (__get_user(c, buf))
 623                         return -EFAULT;
 624                 buf++;
 625                 if ((c1 = *pWritePtr++) != c) {
 626                         printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
 627                                pWritePtr - FLASH_BASE, c1, c);
 628                         return 0;
 629                 }
 630         }
 631
 632         return count;
 633 }
 634
 635
 636 static void kick_open(void)
 637 {
 638         unsigned long flags;
 639
 640         /*
 641          * we want to write a bit pattern XXX1 to Xilinx to enable
 642          * the write gate, which will be open for about the next 2ms.
 643          */
 644         spin_lock_irqsave(&gpio_lock, flags);
 645         cpld_modify(1, 1);
 646         spin_unlock_irqrestore(&gpio_lock, flags);
 647
 648         /*
 649          * let the ISA bus to catch on...
 650          */
 651         udelay(25);
 652 }
 653
 654 static struct file_operations flash_fops =
 655 {
 656         .owner          = THIS_MODULE,
 657         .llseek         = flash_llseek,
 658         .read           = flash_read,
 659         .write          = flash_write,
 660         .ioctl          = flash_ioctl,
 661 };
 662
 663 static struct miscdevice flash_miscdev =
 664 {
 665         FLASH_MINOR,
 666         "nwflash",
 667         &flash_fops
 668 };
 669
 670 static int __init nwflash_init(void)
 671 {
 672         int ret = -ENODEV;
 673
 674         if (machine_is_netwinder()) {
 675                 int id;
 676
 677                 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
 678                 if (!FLASH_BASE)
 679                         goto out;
 680
 681                 id = get_flash_id();
 682                 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
 683                         ret = -ENXIO;
 684                         iounmap((void *)FLASH_BASE);
 685                         printk("Flash: incorrect ID 0x%04X.\n", id);
 686                         goto out;
 687                 }
 688
 689                 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
 690                        NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
 691
 692                 ret = misc_register(&flash_miscdev);
 693                 if (ret < 0) {
 694                         iounmap((void *)FLASH_BASE);
 695                 }
 696         }
 697 out:
 698         return ret;
 699 }
 700
 701 static void __exit nwflash_exit(void)
 702 {
 703         misc_deregister(&flash_miscdev);
 704         iounmap((void *)FLASH_BASE);
 705 }
 706
 707 MODULE_LICENSE("GPL");
 708
 709 MODULE_PARM(flashdebug, "i");
 710
 711 module_init(nwflash_init);
 712 module_exit(nwflash_exit);