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/mutex.h>
  29 #include <linux/jiffies.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 DEFINE_MUTEX(flash_mutex);
  44 static void kick_open(void);
  45 static int get_flash_id(void);
  46 static int erase_block(int nBlock);
  47 static int write_block(unsigned long p, const char __user *buf, int count);
  48
  49 #define KFLASH_SIZE     1024*1024       //1 Meg
  50 #define KFLASH_SIZE4    4*1024*1024     //4 Meg
  51 #define KFLASH_ID       0x89A6          //Intel flash
  52 #define KFLASH_ID4      0xB0D4          //Intel flash 4Meg
  53
  54 static bool flashdebug;         //if set - we will display progress msgs
  55
  56 static int gbWriteEnable;
  57 static int gbWriteBase64Enable;
  58 static volatile unsigned char *FLASH_BASE;
  59 static int gbFlashSize = KFLASH_SIZE;
  60 static DEFINE_MUTEX(nwflash_mutex);
  61
  62 static int get_flash_id(void)
  63 {
  64         volatile unsigned int c1, c2;
  65
  66         /*
  67          * try to get flash chip ID
  68          */
  69         kick_open();
  70         c2 = inb(0x80);
  71         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
  72         udelay(15);
  73         c1 = *(volatile unsigned char *) FLASH_BASE;
  74         c2 = inb(0x80);
  75
  76         /*
  77          * on 4 Meg flash the second byte is actually at offset 2...
  78          */
  79         if (c1 == 0xB0)
  80                 c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
  81         else
  82                 c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
  83
  84         c2 += (c1 << 8);
  85
  86         /*
  87          * set it back to read mode
  88          */
  89         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
  90
  91         if (c2 == KFLASH_ID4)
  92                 gbFlashSize = KFLASH_SIZE4;
  93
  94         return c2;
  95 }
  96
  97 static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
  98 {
  99         mutex_lock(&flash_mutex);
 100         switch (cmd) {
 101         case CMD_WRITE_DISABLE:
 102                 gbWriteBase64Enable = 0;
 103                 gbWriteEnable = 0;
 104                 break;
 105
 106         case CMD_WRITE_ENABLE:
 107                 gbWriteEnable = 1;
 108                 break;
 109
 110         case CMD_WRITE_BASE64K_ENABLE:
 111                 gbWriteBase64Enable = 1;
 112                 break;
 113
 114         default:
 115                 gbWriteBase64Enable = 0;
 116                 gbWriteEnable = 0;
 117                 mutex_unlock(&flash_mutex);
 118                 return -EINVAL;
 119         }
 120         mutex_unlock(&flash_mutex);
 121         return 0;
 122 }
 123
 124 static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
 125                           loff_t *ppos)
 126 {
 127         ssize_t ret;
 128
 129         if (flashdebug)
 130                 printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
 131                        "buffer=%p, count=0x%zx.\n", *ppos, buf, size);
 132         /*
 133          * We now lock against reads and writes. --rmk
 134          */
 135         if (mutex_lock_interruptible(&nwflash_mutex))
 136                 return -ERESTARTSYS;
 137
 138         ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
 139         mutex_unlock(&nwflash_mutex);
 140
 141         return ret;
 142 }
 143
 144 static ssize_t flash_write(struct file *file, const char __user *buf,
 145                            size_t size, loff_t * ppos)
 146 {
 147         unsigned long p = *ppos;
 148         unsigned int count = size;
 149         int written;
 150         int nBlock, temp, rc;
 151         int i, j;
 152
 153         if (flashdebug)
 154                 printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
 155                        p, buf, count);
 156
 157         if (!gbWriteEnable)
 158                 return -EINVAL;
 159
 160         if (p < 64 * 1024 && (!gbWriteBase64Enable))
 161                 return -EINVAL;
 162
 163         /*
 164          * check for out of range pos or count
 165          */
 166         if (p >= gbFlashSize)
 167                 return count ? -ENXIO : 0;
 168
 169         if (count > gbFlashSize - p)
 170                 count = gbFlashSize - p;
 171
 172         if (!access_ok(VERIFY_READ, buf, count))
 173                 return -EFAULT;
 174
 175         /*
 176          * We now lock against reads and writes. --rmk
 177          */
 178         if (mutex_lock_interruptible(&nwflash_mutex))
 179                 return -ERESTARTSYS;
 180
 181         written = 0;
 182
 183         leds_event(led_claim);
 184         leds_event(led_green_on);
 185
 186         nBlock = (int) p >> 16; //block # of 64K bytes
 187
 188         /*
 189          * # of 64K blocks to erase and write
 190          */
 191         temp = ((int) (p + count) >> 16) - nBlock + 1;
 192
 193         /*
 194          * write ends at exactly 64k boundary?
 195          */
 196         if (((int) (p + count) & 0xFFFF) == 0)
 197                 temp -= 1;
 198
 199         if (flashdebug)
 200                 printk(KERN_DEBUG "flash_write: writing %d block(s) "
 201                         "starting at %d.\n", temp, nBlock);
 202
 203         for (; temp; temp--, nBlock++) {
 204                 if (flashdebug)
 205                         printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
 206
 207                 /*
 208                  * first we have to erase the block(s), where we will write...
 209                  */
 210                 i = 0;
 211                 j = 0;
 212           RetryBlock:
 213                 do {
 214                         rc = erase_block(nBlock);
 215                         i++;
 216                 } while (rc && i < 10);
 217
 218                 if (rc) {
 219                         printk(KERN_ERR "flash_write: erase error %x\n", rc);
 220                         break;
 221                 }
 222                 if (flashdebug)
 223                         printk(KERN_DEBUG "flash_write: writing offset %lX, "
 224                                "from buf %p, bytes left %X.\n", p, buf,
 225                                count - written);
 226
 227                 /*
 228                  * write_block will limit write to space left in this block
 229                  */
 230                 rc = write_block(p, buf, count - written);
 231                 j++;
 232
 233                 /*
 234                  * if somehow write verify failed? Can't happen??
 235                  */
 236                 if (!rc) {
 237                         /*
 238                          * retry up to 10 times
 239                          */
 240                         if (j < 10)
 241                                 goto RetryBlock;
 242                         else
 243                                 /*
 244                                  * else quit with error...
 245                                  */
 246                                 rc = -1;
 247
 248                 }
 249                 if (rc < 0) {
 250                         printk(KERN_ERR "flash_write: write error %X\n", rc);
 251                         break;
 252                 }
 253                 p += rc;
 254                 buf += rc;
 255                 written += rc;
 256                 *ppos += rc;
 257
 258                 if (flashdebug)
 259                         printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
 260         }
 261
 262         /*
 263          * restore reg on exit
 264          */
 265         leds_event(led_release);
 266
 267         mutex_unlock(&nwflash_mutex);
 268
 269         return written;
 270 }
 271
 272
 273 /*
 274  * The memory devices use the full 32/64 bits of the offset, and so we cannot
 275  * check against negative addresses: they are ok. The return value is weird,
 276  * though, in that case (0).
 277  *
 278  * also note that seeking relative to the "end of file" isn't supported:
 279  * it has no meaning, so it returns -EINVAL.
 280  */
 281 static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
 282 {
 283         loff_t ret;
 284
 285         mutex_lock(&flash_mutex);
 286         if (flashdebug)
 287                 printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
 288                        (unsigned int) offset, orig);
 289
 290         switch (orig) {
 291         case 0:
 292                 if (offset < 0) {
 293                         ret = -EINVAL;
 294                         break;
 295                 }
 296
 297                 if ((unsigned int) offset > gbFlashSize) {
 298                         ret = -EINVAL;
 299                         break;
 300                 }
 301
 302                 file->f_pos = (unsigned int) offset;
 303                 ret = file->f_pos;
 304                 break;
 305         case 1:
 306                 if ((file->f_pos + offset) > gbFlashSize) {
 307                         ret = -EINVAL;
 308                         break;
 309                 }
 310                 if ((file->f_pos + offset) < 0) {
 311                         ret = -EINVAL;
 312                         break;
 313                 }
 314                 file->f_pos += offset;
 315                 ret = file->f_pos;
 316                 break;
 317         default:
 318                 ret = -EINVAL;
 319         }
 320         mutex_unlock(&flash_mutex);
 321         return ret;
 322 }
 323
 324
 325 /*
 326  * assume that main Write routine did the parameter checking...
 327  * so just go ahead and erase, what requested!
 328  */
 329
 330 static int erase_block(int nBlock)
 331 {
 332         volatile unsigned int c1;
 333         volatile unsigned char *pWritePtr;
 334         unsigned long timeout;
 335         int temp, temp1;
 336
 337         /*
 338          * orange LED == erase
 339          */
 340         leds_event(led_amber_on);
 341
 342         /*
 343          * reset footbridge to the correct offset 0 (...0..3)
 344          */
 345         *CSR_ROMWRITEREG = 0;
 346
 347         /*
 348          * dummy ROM read
 349          */
 350         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 351
 352         kick_open();
 353         /*
 354          * reset status if old errors
 355          */
 356         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 357
 358         /*
 359          * erase a block...
 360          * aim at the middle of a current block...
 361          */
 362         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
 363         /*
 364          * dummy read
 365          */
 366         c1 = *pWritePtr;
 367
 368         kick_open();
 369         /*
 370          * erase
 371          */
 372         *(volatile unsigned char *) pWritePtr = 0x20;
 373
 374         /*
 375          * confirm
 376          */
 377         *(volatile unsigned char *) pWritePtr = 0xD0;
 378
 379         /*
 380          * wait 10 ms
 381          */
 382         msleep(10);
 383
 384         /*
 385          * wait while erasing in process (up to 10 sec)
 386          */
 387         timeout = jiffies + 10 * HZ;
 388         c1 = 0;
 389         while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
 390                 msleep(10);
 391                 /*
 392                  * read any address
 393                  */
 394                 c1 = *(volatile unsigned char *) (pWritePtr);
 395                 //              printk("Flash_erase: status=%X.\n",c1);
 396         }
 397
 398         /*
 399          * set flash for normal read access
 400          */
 401         kick_open();
 402 //      *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
 403         *(volatile unsigned char *) pWritePtr = 0xFF;   //back to normal operation
 404
 405         /*
 406          * check if erase errors were reported
 407          */
 408         if (c1 & 0x20) {
 409                 printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
 410
 411                 /*
 412                  * reset error
 413                  */
 414                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 415                 return -2;
 416         }
 417
 418         /*
 419          * just to make sure - verify if erased OK...
 420          */
 421         msleep(10);
 422
 423         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
 424
 425         for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
 426                 if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
 427                         printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
 428                                pWritePtr, temp1);
 429                         return -1;
 430                 }
 431         }
 432
 433         return 0;
 434
 435 }
 436
 437 /*
 438  * write_block will limit number of bytes written to the space in this block
 439  */
 440 static int write_block(unsigned long p, const char __user *buf, int count)
 441 {
 442         volatile unsigned int c1;
 443         volatile unsigned int c2;
 444         unsigned char *pWritePtr;
 445         unsigned int uAddress;
 446         unsigned int offset;
 447         unsigned long timeout;
 448         unsigned long timeout1;
 449
 450         /*
 451          * red LED == write
 452          */
 453         leds_event(led_amber_off);
 454         leds_event(led_red_on);
 455
 456         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 457
 458         /*
 459          * check if write will end in this block....
 460          */
 461         offset = p & 0xFFFF;
 462
 463         if (offset + count > 0x10000)
 464                 count = 0x10000 - offset;
 465
 466         /*
 467          * wait up to 30 sec for this block
 468          */
 469         timeout = jiffies + 30 * HZ;
 470
 471         for (offset = 0; offset < count; offset++, pWritePtr++) {
 472                 uAddress = (unsigned int) pWritePtr;
 473                 uAddress &= 0xFFFFFFFC;
 474                 if (__get_user(c2, buf + offset))
 475                         return -EFAULT;
 476
 477           WriteRetry:
 478                 /*
 479                  * dummy read
 480                  */
 481                 c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 482
 483                 /*
 484                  * kick open the write gate
 485                  */
 486                 kick_open();
 487
 488                 /*
 489                  * program footbridge to the correct offset...0..3
 490                  */
 491                 *CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
 492
 493                 /*
 494                  * write cmd
 495                  */
 496                 *(volatile unsigned char *) (uAddress) = 0x40;
 497
 498                 /*
 499                  * data to write
 500                  */
 501                 *(volatile unsigned char *) (uAddress) = c2;
 502
 503                 /*
 504                  * get status
 505                  */
 506                 *(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
 507
 508                 c1 = 0;
 509
 510                 /*
 511                  * wait up to 1 sec for this byte
 512                  */
 513                 timeout1 = jiffies + 1 * HZ;
 514
 515                 /*
 516                  * while not ready...
 517                  */
 518                 while (!(c1 & 0x80) && time_before(jiffies, timeout1))
 519                         c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
 520
 521                 /*
 522                  * if timeout getting status
 523                  */
 524                 if (time_after_eq(jiffies, timeout1)) {
 525                         kick_open();
 526                         /*
 527                          * reset err
 528                          */
 529                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 530
 531                         goto WriteRetry;
 532                 }
 533                 /*
 534                  * switch on read access, as a default flash operation mode
 535                  */
 536                 kick_open();
 537                 /*
 538                  * read access
 539                  */
 540                 *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
 541
 542                 /*
 543                  * if hardware reports an error writing, and not timeout -
 544                  * reset the chip and retry
 545                  */
 546                 if (c1 & 0x10) {
 547                         kick_open();
 548                         /*
 549                          * reset err
 550                          */
 551                         *(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
 552
 553                         /*
 554                          * before timeout?
 555                          */
 556                         if (time_before(jiffies, timeout)) {
 557                                 if (flashdebug)
 558                                         printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
 559                                                pWritePtr - FLASH_BASE);
 560
 561                                 /*
 562                                  * no LED == waiting
 563                                  */
 564                                 leds_event(led_amber_off);
 565                                 /*
 566                                  * wait couple ms
 567                                  */
 568                                 msleep(10);
 569                                 /*
 570                                  * red LED == write
 571                                  */
 572                                 leds_event(led_red_on);
 573
 574                                 goto WriteRetry;
 575                         } else {
 576                                 printk(KERN_ERR "write_block: timeout at 0x%X\n",
 577                                        pWritePtr - FLASH_BASE);
 578                                 /*
 579                                  * return error -2
 580                                  */
 581                                 return -2;
 582
 583                         }
 584                 }
 585         }
 586
 587         /*
 588          * green LED == read/verify
 589          */
 590         leds_event(led_amber_off);
 591         leds_event(led_green_on);
 592
 593         msleep(10);
 594
 595         pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
 596
 597         for (offset = 0; offset < count; offset++) {
 598                 char c, c1;
 599                 if (__get_user(c, buf))
 600                         return -EFAULT;
 601                 buf++;
 602                 if ((c1 = *pWritePtr++) != c) {
 603                         printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
 604                                pWritePtr - FLASH_BASE, c1, c);
 605                         return 0;
 606                 }
 607         }
 608
 609         return count;
 610 }
 611
 612
 613 static void kick_open(void)
 614 {
 615         unsigned long flags;
 616
 617         /*
 618          * we want to write a bit pattern XXX1 to Xilinx to enable
 619          * the write gate, which will be open for about the next 2ms.
 620          */
 621         spin_lock_irqsave(&nw_gpio_lock, flags);
 622         nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
 623         spin_unlock_irqrestore(&nw_gpio_lock, flags);
 624
 625         /*
 626          * let the ISA bus to catch on...
 627          */
 628         udelay(25);
 629 }
 630
 631 static const struct file_operations flash_fops =
 632 {
 633         .owner          = THIS_MODULE,
 634         .llseek         = flash_llseek,
 635         .read           = flash_read,
 636         .write          = flash_write,
 637         .unlocked_ioctl = flash_ioctl,
 638 };
 639
 640 static struct miscdevice flash_miscdev =
 641 {
 642         FLASH_MINOR,
 643         "nwflash",
 644         &flash_fops
 645 };
 646
 647 static int __init nwflash_init(void)
 648 {
 649         int ret = -ENODEV;
 650
 651         if (machine_is_netwinder()) {
 652                 int id;
 653
 654                 FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
 655                 if (!FLASH_BASE)
 656                         goto out;
 657
 658                 id = get_flash_id();
 659                 if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
 660                         ret = -ENXIO;
 661                         iounmap((void *)FLASH_BASE);
 662                         printk("Flash: incorrect ID 0x%04X.\n", id);
 663                         goto out;
 664                 }
 665
 666                 printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
 667                        NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
 668
 669                 ret = misc_register(&flash_miscdev);
 670                 if (ret < 0) {
 671                         iounmap((void *)FLASH_BASE);
 672                 }
 673         }
 674 out:
 675         return ret;
 676 }
 677
 678 static void __exit nwflash_exit(void)
 679 {
 680         misc_deregister(&flash_miscdev);
 681         iounmap((void *)FLASH_BASE);
 682 }
 683
 684 MODULE_LICENSE("GPL");
 685
 686 module_param(flashdebug, bool, 0644);
 687
 688 module_init(nwflash_init);
 689 module_exit(nwflash_exit);