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