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/miscdevice.h>
  25 #include <linux/spinlock.h>
  26 #include <linux/rwsem.h>
  27 #include <linux/init.h>
  28 #include <linux/smp_lock.h>
  29 #include <linux/mutex.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 __user *buf, int count);
  47
  48 #define KFLASH_SIZE     1024*1024       //1 Meg
  49 #define KFLASH_SIZE4    4*1024*1024     //4 Meg
  50 #define KFLASH_ID       0x89A6          //Intel flash
  51 #define KFLASH_ID4      0xB0D4          //Intel flash 4Meg
  52
  53 static int flashdebug;          //if set - we will display progress msgs
  54
  55 static int gbWriteEnable;
  56 static int gbWriteBase64Enable;
  57 static volatile unsigned char *FLASH_BASE;
  58 static int gbFlashSize = KFLASH_SIZE;
  59 static DEFINE_MUTEX(nwflash_mutex);
  60
  61 static int get_flash_id(void)
  62 {
  63         volatile unsigned int c1, c2;
  64
  65         /*
  66          * try to get flash chip ID
  67          */
  68         kick_open();
  69         c2 = inb(0x80);
  70         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
  71         udelay(15);
  72         c1 = *(volatile unsigned char *) FLASH_BASE;
  73         c2 = inb(0x80);
  74
  75         /*
  76          * on 4 Meg flash the second byte is actually at offset 2...
  77          */
  78         if (c1 == 0xB0)
  79                 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
  80         else
  81                 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
  82
  83         c2 += (c1 << 8);
  84
  85         /*
  86          * set it back to read mode
  87          */
  88         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
  89
  90         if (c2 == KFLASH_ID4)
  91                 gbFlashSize = KFLASH_SIZE4;
  92
  93         return c2;
  94 }
  95
  96 static int flash_ioctl(struct inode *inodep, struct file *filep, unsigned int cmd, unsigned long arg)
  97 {
  98         switch (cmd) {
  99         case CMD_WRITE_DISABLE:
 100                 gbWriteBase64Enable = 0;
 101                 gbWriteEnable = 0;
 102                 break;
 103
 104         case CMD_WRITE_ENABLE:
 105                 gbWriteEnable = 1;
 106                 break;
 107
 108         case CMD_WRITE_BASE64K_ENABLE:
 109                 gbWriteBase64Enable = 1;
 110                 break;
 111
 112         default:
 113                 gbWriteBase64Enable = 0;
 114                 gbWriteEnable = 0;
 115                 return -EINVAL;
 116         }
 117         return 0;
 118 }
 119
 120 static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
 121                           loff_t *ppos)
 122 {
 123         ssize_t ret;
 124
 125         if (flashdebug)
 126                 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
 127                        "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
 128         /*
 129          * We now lock against reads and writes. --rmk
 130          */
 131         if (mutex_lock_interruptible(&nwflash_mutex))
 132                 return -ERESTARTSYS;
 133
 134         ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
 135         mutex_unlock(&nwflash_mutex);
 136
 137         return ret;
 138 }
 139
 140 static ssize_t flash_write(struct file *file, const char __user *buf,
 141                            size_t size, loff_t * ppos)
 142 {
 143         unsigned long p = *ppos;
 144         unsigned int count = size;
 145         int written;
 146         int nBlock, temp, rc;
 147         int i, j;
 148
 149         if (flashdebug)
 150                 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
 151                        p, buf, count);
 152
 153         if (!gbWriteEnable)
 154                 return -EINVAL;
 155
 156         if (p < 64 * 1024 && (!gbWriteBase64Enable))
 157                 return -EINVAL;
 158
 159         /*
 160          * check for out of range pos or count
 161          */
 162         if (p >= gbFlashSize)
 163                 return count ? -ENXIO : 0;
 164
 165         if (count > gbFlashSize - p)
 166                 count = gbFlashSize - p;
 167
 168         if (!access_ok(VERIFY_READ, buf, count))
 169                 return -EFAULT;
 170
 171         /*
 172          * We now lock against reads and writes. --rmk
 173          */
 174         if (mutex_lock_interruptible(&nwflash_mutex))
 175                 return -ERESTARTSYS;
 176
 177         written = 0;
 178
 179         leds_event(led_claim);
 180         leds_event(led_green_on);
 181
 182         nBlock = (int) p >> 16; //block # of 64K bytes
 183
 184         /*
 185          * # of 64K blocks to erase and write
 186          */
 187         temp = ((int) (p + count) >> 16) - nBlock + 1;
 188
 189         /*
 190          * write ends at exactly 64k boundary?
 191          */
 192         if (((int) (p + count) & 0xFFFF) == 0)
 193                 temp -= 1;
 194
 195         if (flashdebug)
 196                 printk(KERN_DEBUG "flash_write: writing %d block(s) "
 197                         "starting at %d.\n", temp, nBlock);
 198
 199         for (; temp; temp--, nBlock++) {
 200                 if (flashdebug)
 201                         printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
 202
 203                 /*
 204                  * first we have to erase the block(s), where we will write...
 205                  */
 206                 i = 0;
 207                 j = 0;
 208           RetryBlock:
 209                 do {
 210                         rc = erase_block(nBlock);
 211                         i++;
 212                 } while (rc && i < 10);
 213
 214                 if (rc) {
 215                         printk(KERN_ERR "flash_write: erase error %x\n", rc);
 216                         break;
 217                 }
 218                 if (flashdebug)
 219                         printk(KERN_DEBUG "flash_write: writing offset %lX, "
 220                                "from buf %p, bytes left %X.\n", p, buf,
 221                                count - written);
 222
 223                 /*
 224                  * write_block will limit write to space left in this block
 225                  */
 226                 rc = write_block(p, buf, count - written);
 227                 j++;
 228
 229                 /*
 230                  * if somehow write verify failed? Can't happen??
 231                  */
 232                 if (!rc) {
 233                         /*
 234                          * retry up to 10 times
 235                          */
 236                         if (j < 10)
 237                                 goto RetryBlock;
 238                         else
 239                                 /*
 240                                  * else quit with error...
 241                                  */
 242                                 rc = -1;
 243
 244                 }
 245                 if (rc < 0) {
 246                         printk(KERN_ERR "flash_write: write error %X\n", rc);
 247                         break;
 248                 }
 249                 p += rc;
 250                 buf += rc;
 251                 written += rc;
 252                 *ppos += rc;
 253
 254                 if (flashdebug)
 255                         printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
 256         }
 257
 258         /*
 259          * restore reg on exit
 260          */
 261         leds_event(led_release);
 262
 263         mutex_unlock(&nwflash_mutex);
 264
 265         return written;
 266 }
 267
 268
 269 /*
 270  * The memory devices use the full 32/64 bits of the offset, and so we cannot
 271  * check against negative addresses: they are ok. The return value is weird,
 272  * though, in that case (0).
 273  *
 274  * also note that seeking relative to the "end of file" isn't supported:
 275  * it has no meaning, so it returns -EINVAL.
 276  */
 277 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
 278 {
 279         loff_t ret;
 280
 281         lock_kernel();
 282         if (flashdebug)
 283                 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
 284                        (unsigned int) offset, orig);
 285
 286         switch (orig) {
 287         case 0:
 288                 if (offset < 0) {
 289                         ret = -EINVAL;
 290                         break;
 291                 }
 292
 293                 if ((unsigned int) offset > gbFlashSize) {
 294                         ret = -EINVAL;
 295                         break;
 296                 }
 297
 298                 file->f_pos = (unsigned int) offset;
 299                 ret = file->f_pos;
 300                 break;
 301         case 1:
 302                 if ((file->f_pos + offset) > gbFlashSize) {
 303                         ret = -EINVAL;
 304                         break;
 305                 }
 306                 if ((file->f_pos + offset) < 0) {
 307                         ret = -EINVAL;
 308                         break;
 309                 }
 310                 file->f_pos += offset;
 311                 ret = file->f_pos;
 312                 break;
 313         default:
 314                 ret = -EINVAL;
 315         }
 316         unlock_kernel();
 317         return ret;
 318 }
 319
 320
 321 /*
 322  * assume that main Write routine did the parameter checking...
 323  * so just go ahead and erase, what requested!
 324  */
 325
 326 static int erase_block(int nBlock)
 327 {
 328         volatile unsigned int c1;
 329         volatile unsigned char *pWritePtr;
 330         unsigned long timeout;
 331         int temp, temp1;
 332
 333         /*
 334          * orange LED == erase
 335          */
 336         leds_event(led_amber_on);
 337
 338         /*
 339          * reset footbridge to the correct offset 0 (...0..3)
 340          */
 341         *CSR_ROMWRITEREG = 0;
 342
 343         /*
 344          * dummy ROM read
 345          */
 346         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 347
 348         kick_open();
 349         /*
 350          * reset status if old errors
 351          */
 352         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 353
 354         /*
 355          * erase a block...
 356          * aim at the middle of a current block...
 357          */
 358         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
 359         /*
 360          * dummy read
 361          */
 362         c1 = *pWritePtr;
 363
 364         kick_open();
 365         /*
 366          * erase
 367          */
 368         *(volatile unsigned char *) pWritePtr = 0x20;
 369
 370         /*
 371          * confirm
 372          */
 373         *(volatile unsigned char *) pWritePtr = 0xD0;
 374
 375         /*
 376          * wait 10 ms
 377          */
 378         msleep(10);
 379
 380         /*
 381          * wait while erasing in process (up to 10 sec)
 382          */
 383         timeout = jiffies + 10 * HZ;
 384         c1 = 0;
 385         while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
 386                 msleep(10);
 387                 /*
 388                  * read any address
 389                  */
 390                 c1 = *(volatile unsigned char *) (pWritePtr);
 391                 //              printk("Flash_erase: status=%X.\n",c1);
 392         }
 393
 394         /*
 395          * set flash for normal read access
 396          */
 397         kick_open();
 398 //      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
 399         *(volatile unsigned char *) pWritePtr = 0xFF;   //back to normal operation
 400
 401         /*
 402          * check if erase errors were reported
 403          */
 404         if (c1 & 0x20) {
 405                 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
 406
 407                 /*
 408                  * reset error
 409                  */
 410                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 411                 return -2;
 412         }
 413
 414         /*
 415          * just to make sure - verify if erased OK...
 416          */
 417         msleep(10);
 418
 419         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
 420
 421         for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
 422                 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
 423                         printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
 424                                pWritePtr, temp1);
 425                         return -1;
 426                 }
 427         }
 428
 429         return 0;
 430
 431 }
 432
 433 /*
 434  * write_block will limit number of bytes written to the space in this block
 435  */
 436 static int write_block(unsigned long p, const char __user *buf, int count)
 437 {
 438         volatile unsigned int c1;
 439         volatile unsigned int c2;
 440         unsigned char *pWritePtr;
 441         unsigned int uAddress;
 442         unsigned int offset;
 443         unsigned long timeout;
 444         unsigned long timeout1;
 445
 446         /*
 447          * red LED == write
 448          */
 449         leds_event(led_amber_off);
 450         leds_event(led_red_on);
 451
 452         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 453
 454         /*
 455          * check if write will end in this block....
 456          */
 457         offset = p & 0xFFFF;
 458
 459         if (offset + count > 0x10000)
 460                 count = 0x10000 - offset;
 461
 462         /*
 463          * wait up to 30 sec for this block
 464          */
 465         timeout = jiffies + 30 * HZ;
 466
 467         for (offset = 0; offset < count; offset++, pWritePtr++) {
 468                 uAddress = (unsigned int) pWritePtr;
 469                 uAddress &= 0xFFFFFFFC;
 470                 if (__get_user(c2, buf + offset))
 471                         return -EFAULT;
 472
 473           WriteRetry:
 474                 /*
 475                  * dummy read
 476                  */
 477                 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 478
 479                 /*
 480                  * kick open the write gate
 481                  */
 482                 kick_open();
 483
 484                 /*
 485                  * program footbridge to the correct offset...0..3
 486                  */
 487                 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
 488
 489                 /*
 490                  * write cmd
 491                  */
 492                 *(volatile unsigned char *) (uAddress) = 0x40;
 493
 494                 /*
 495                  * data to write
 496                  */
 497                 *(volatile unsigned char *) (uAddress) = c2;
 498
 499                 /*
 500                  * get status
 501                  */
 502                 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
 503
 504                 c1 = 0;
 505
 506                 /*
 507                  * wait up to 1 sec for this byte
 508                  */
 509                 timeout1 = jiffies + 1 * HZ;
 510
 511                 /*
 512                  * while not ready...
 513                  */
 514                 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
 515                         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 516
 517                 /*
 518                  * if timeout getting status
 519                  */
 520                 if (time_after_eq(jiffies, timeout1)) {
 521                         kick_open();
 522                         /*
 523                          * reset err
 524                          */
 525                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 526
 527                         goto WriteRetry;
 528                 }
 529                 /*
 530                  * switch on read access, as a default flash operation mode
 531                  */
 532                 kick_open();
 533                 /*
 534                  * read access
 535                  */
 536                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 537
 538                 /*
 539                  * if hardware reports an error writing, and not timeout -
 540                  * reset the chip and retry
 541                  */
 542                 if (c1 & 0x10) {
 543                         kick_open();
 544                         /*
 545                          * reset err
 546                          */
 547                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 548
 549                         /*
 550                          * before timeout?
 551                          */
 552                         if (time_before(jiffies, timeout)) {
 553                                 if (flashdebug)
 554                                         printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
 555                                                pWritePtr - FLASH_BASE);
 556
 557                                 /*
 558                                  * no LED == waiting
 559                                  */
 560                                 leds_event(led_amber_off);
 561                                 /*
 562                                  * wait couple ms
 563                                  */
 564                                 msleep(10);
 565                                 /*
 566                                  * red LED == write
 567                                  */
 568                                 leds_event(led_red_on);
 569
 570                                 goto WriteRetry;
 571                         } else {
 572                                 printk(KERN_ERR "write_block: timeout at 0x%X\n",
 573                                        pWritePtr - FLASH_BASE);
 574                                 /*
 575                                  * return error -2
 576                                  */
 577                                 return -2;
 578
 579                         }
 580                 }
 581         }
 582
 583         /*
 584          * green LED == read/verify
 585          */
 586         leds_event(led_amber_off);
 587         leds_event(led_green_on);
 588
 589         msleep(10);
 590
 591         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 592
 593         for (offset = 0; offset < count; offset++) {
 594                 char c, c1;
 595                 if (__get_user(c, buf))
 596                         return -EFAULT;
 597                 buf++;
 598                 if ((c1 = *pWritePtr++) != c) {
 599                         printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
 600                                pWritePtr - FLASH_BASE, c1, c);
 601                         return 0;
 602                 }
 603         }
 604
 605         return count;
 606 }
 607
 608
 609 static void kick_open(void)
 610 {
 611         unsigned long flags;
 612
 613         /*
 614          * we want to write a bit pattern XXX1 to Xilinx to enable
 615          * the write gate, which will be open for about the next 2ms.
 616          */
 617         spin_lock_irqsave(&nw_gpio_lock, flags);
 618         nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
 619         spin_unlock_irqrestore(&nw_gpio_lock, flags);
 620
 621         /*
 622          * let the ISA bus to catch on...
 623          */
 624         udelay(25);
 625 }
 626
 627 static const struct file_operations flash_fops =
 628 {
 629         .owner          = THIS_MODULE,
 630         .llseek         = flash_llseek,
 631         .read           = flash_read,
 632         .write          = flash_write,
 633         .ioctl          = flash_ioctl,
 634 };
 635
 636 static struct miscdevice flash_miscdev =
 637 {
 638         FLASH_MINOR,
 639         "nwflash",
 640         &flash_fops
 641 };
 642
 643 static int __init nwflash_init(void)
 644 {
 645         int ret = -ENODEV;
 646
 647         if (machine_is_netwinder()) {
 648                 int id;
 649
 650                 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
 651                 if (!FLASH_BASE)
 652                         goto out;
 653
 654                 id = get_flash_id();
 655                 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
 656                         ret = -ENXIO;
 657                         iounmap((void *)FLASH_BASE);
 658                         printk("Flash: incorrect ID 0x%04X.\n", id);
 659                         goto out;
 660                 }
 661
 662                 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
 663                        NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
 664
 665                 ret = misc_register(&flash_miscdev);
 666                 if (ret < 0) {
 667                         iounmap((void *)FLASH_BASE);
 668                 }
 669         }
 670 out:
 671         return ret;
 672 }
 673
 674 static void __exit nwflash_exit(void)
 675 {
 676         misc_deregister(&flash_miscdev);
 677         iounmap((void *)FLASH_BASE);
 678 }
 679
 680 MODULE_LICENSE("GPL");
 681
 682 module_param(flashdebug, bool, 0644);
 683
 684 module_init(nwflash_init);
 685 module_exit(nwflash_exit);