drivers/mtd/devices/doc1000.c

   1 /*======================================================================
   2
   3   $Id: doc1000.c,v 1.17 2003/01/24 13:33:20 dwmw2 Exp $
   4
   5 ======================================================================*/
   6
   7
   8 #include <linux/config.h>
   9 #include <linux/module.h>
  10 #include <asm/uaccess.h>
  11 #include <linux/types.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/slab.h>
  16 #include <linux/string.h>
  17 #include <linux/timer.h>
  18 #include <linux/major.h>
  19 #include <linux/fs.h>
  20 #include <linux/ioctl.h>
  21 #include <asm/io.h>
  22 #include <asm/system.h>
  23 #include <linux/delay.h>
  24 #include <linux/init.h>
  25
  26 #include <linux/mtd/mtd.h>
  27 #include <linux/mtd/iflash.h>
  28
  29 /* Parameters that can be set with 'insmod' */
  30
  31 static u_long base              = 0xe0000;
  32 static int erase_timeout        = 10*HZ;        /* in ticks */
  33 static int retry_limit          = 4;            /* write retries */
  34 static u_long max_tries         = 4096;         /* status polling */
  35
  36 MODULE_PARM(base,"l");
  37 MODULE_PARM(erase_timeout, "i");
  38 MODULE_PARM(retry_limit, "i");
  39 MODULE_PARM(max_tries, "i");
  40
  41 #define WINDOW_SIZE 0x2000
  42 #define WINDOW_MASK (WINDOW_SIZE - 1)
  43 #define PAGEREG_LO (WINDOW_SIZE)
  44 #define PAGEREG_HI (WINDOW_SIZE + 2)
  45
  46 static struct mtd_info *mymtd;
  47 static struct timer_list flashcard_timer;
  48
  49 #define MAX_CELLS               32
  50 #define MAX_FLASH_DEVICES       8
  51
  52 /* A flash region is composed of one or more "cells", where we allow
  53    simultaneous erases if they are in different cells */
  54
  55
  56
  57 struct mypriv {
  58         u_char *baseaddr;
  59         u_short curpage;
  60         u_char locked;
  61         u_short numdevices;
  62         u_char interleave;
  63         struct erase_info *cur_erases;
  64         wait_queue_head_t wq;
  65         u_char devstat[MAX_FLASH_DEVICES];
  66         u_long devshift;
  67 };
  68
  69
  70 static void flashcard_periodic(u_long data);
  71 static int flashcard_erase (struct mtd_info *mtd, struct erase_info *instr);
  72 static int flashcard_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf);
  73 static int flashcard_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf);
  74 static void flashcard_sync (struct mtd_info *mtd);
  75
  76 static inline void resume_erase(volatile u_char *addr);
  77 static inline int suspend_erase(volatile u_char *addr);
  78 static inline int byte_write (volatile u_char *addr, u_char byte);
  79 static inline int word_write (volatile u_char *addr, __u16 word);
  80 static inline int check_write(volatile u_char *addr);
  81 static inline void block_erase (volatile u_char *addr);
  82 static inline int check_erase(volatile u_char *addr);
  83
  84 #ifdef CONFIG_SMP
  85 #warning This is definitely not SMP safe. Lock the paging mechanism.
  86 #endif
  87
  88 static u_char *pagein(struct mtd_info *mtd, u_long addr)
  89 {
  90   struct mypriv *priv=mtd->priv;
  91   u_short page = addr >> 13;
  92
  93   priv->baseaddr[PAGEREG_LO] = page & 0xff;
  94   priv->baseaddr[PAGEREG_HI] = page >> 8;
  95   priv->curpage = page;
  96
  97   return &priv->baseaddr[addr & WINDOW_MASK];
  98 }
  99
 100
 101 void flashcard_sync (struct mtd_info *mtd)
 102 {
 103         struct mypriv *priv=mtd->priv;
 104
 105         flashcard_periodic((u_long) mtd);
 106         printk("sync...");
 107         if (priv->cur_erases)
 108                 interruptible_sleep_on(&priv->wq);
 109         printk("Done.\n");
 110 }
 111
 112 int flashcard_erase (struct mtd_info *mtd, struct erase_info *instr)
 113 {
 114         u_char *pageaddr;
 115         struct mypriv *priv=mtd->priv;
 116         struct erase_info **tmp=&priv->cur_erases;
 117
 118         if (instr->len != mtd->erasesize)
 119                 return -EINVAL;
 120         if (instr->addr + instr->len > mtd->size)
 121                 return -EINVAL;
 122
 123         pageaddr=pagein(mtd,instr->addr);
 124         instr->mtd = mtd;
 125         instr->dev = instr->addr >> priv->devshift;
 126         instr->cell = (instr->addr - (instr->dev << priv->devshift)) / mtd->erasesize;
 127         instr->next = NULL;
 128         instr->state = MTD_ERASE_PENDING;
 129
 130         while (*tmp)
 131         {
 132                 tmp = &((*tmp) -> next);
 133         }
 134
 135         *tmp = instr;
 136         flashcard_periodic((u_long)mtd);
 137         return 0;
 138 }
 139
 140 static inline int suspend_erase(volatile u_char *addr)
 141 {
 142         __u16 status;
 143         u_long i = 0;
 144
 145         writew(IF_ERASE_SUSPEND, addr);
 146         writew(IF_READ_CSR, addr);
 147
 148         do {
 149                 status = readw(addr);
 150                 if ((status & CSR_WR_READY) == CSR_WR_READY)
 151                         return 0;
 152                 i++;
 153         } while(i < max_tries);
 154
 155         printk(KERN_NOTICE "flashcard: suspend_erase timed out, status 0x%x\n", status);
 156         return -EIO;
 157
 158 }
 159
 160 static inline void resume_erase(volatile u_char *addr)
 161 {
 162         __u16 status;
 163
 164         writew(IF_READ_CSR, addr);
 165         status = readw(addr);
 166
 167         /* Only give resume signal if the erase is really suspended */
 168         if (status & CSR_ERA_SUSPEND)
 169                 writew(IF_CONFIRM, addr);
 170 }
 171
 172 static inline int byte_write (volatile u_char *addr, u_char byte)
 173 {
 174         register u_char status;
 175         register u_short i = 0;
 176
 177         do {
 178                 status = readb(addr);
 179                 if (status & CSR_WR_READY)
 180                 {
 181                         writeb(IF_WRITE & 0xff, addr);
 182                         writeb(byte, addr);
 183                         return 0;
 184                 }
 185                 i++;
 186         } while(i < max_tries);
 187
 188
 189         printk(KERN_NOTICE "flashcard: byte_write timed out, status 0x%x\n",status);
 190         return -EIO;
 191 }
 192
 193 static inline int word_write (volatile u_char *addr, __u16 word)
 194 {
 195         register u_short status;
 196         register u_short i = 0;
 197
 198         do {
 199                 status = readw(addr);
 200                 if ((status & CSR_WR_READY) == CSR_WR_READY)
 201                 {
 202                         writew(IF_WRITE, addr);
 203                         writew(word, addr);
 204                         return 0;
 205                 }
 206                 i++;
 207         } while(i < max_tries);
 208
 209         printk(KERN_NOTICE "flashcard: word_write timed out at %p, status 0x%x\n", addr, status);
 210         return -EIO;
 211 }
 212
 213 static inline void reset_block(volatile u_char *addr)
 214 {
 215         u_short i;
 216         __u16 status;
 217
 218         writew(IF_CLEAR_CSR, addr);
 219
 220         for (i = 0; i < 100; i++) {
 221                 writew(IF_READ_CSR, addr);
 222                 status = readw(addr);
 223                 if (status != 0xffff) break;
 224                 udelay(1000);
 225         }
 226
 227         writew(IF_READ_CSR, addr);
 228 }
 229
 230 static inline int check_write(volatile u_char *addr)
 231 {
 232         u_short status, i = 0;
 233
 234         writew(IF_READ_CSR, addr);
 235
 236         do {
 237                 status = readw(addr);
 238                 if (status & (CSR_WR_ERR | CSR_VPP_LOW))
 239                 {
 240                         printk(KERN_NOTICE "flashcard: write failure at %p, status 0x%x\n", addr, status);
 241                         reset_block(addr);
 242                         return -EIO;
 243                 }
 244                 if ((status & CSR_WR_READY) == CSR_WR_READY)
 245                         return 0;
 246                 i++;
 247         } while (i < max_tries);
 248
 249         printk(KERN_NOTICE "flashcard: write timed out at %p, status 0x%x\n", addr, status);
 250         return -EIO;
 251 }
 252
 253
 254 int flashcard_read (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf)
 255 {
 256         u_char *pageaddr=pagein(mtd,from);
 257         struct mypriv *priv=mtd->priv;
 258         u_char device = from >> priv->devshift;
 259         u_char cell = (int) (from - (device << priv->devshift)) / mtd->erasesize;
 260         int ret = 0, timeron = 0;
 261
 262         if ((from & WINDOW_MASK) + len <= WINDOW_SIZE)
 263                 *retlen = len;
 264         else
 265                 *retlen = WINDOW_SIZE - (from & WINDOW_MASK);
 266
 267         if (priv->devstat[device])
 268         {
 269
 270                 /* There is an erase in progress or pending for this device. Stop it */
 271                 timeron = del_timer(&flashcard_timer);
 272
 273                 if (priv->cur_erases && priv->cur_erases->cell == cell)
 274
 275                 {
 276                         /* The erase is on the current cell. Just return all 0xff */
 277                         add_timer(&flashcard_timer);
 278
 279
 280                         printk("Cell %d currently erasing. Setting to all 0xff\n",cell);
 281                         memset(buf, 0xff, *retlen);
 282                         return 0;
 283                 }
 284                 if (priv->devstat[device] == MTD_ERASING)
 285                 {
 286                         ret = suspend_erase(pageaddr);
 287                         priv->devstat[device] = MTD_ERASE_SUSPEND;
 288
 289                         if (ret)
 290                         {
 291                                 printk("flashcard: failed to suspend erase\n");
 292                                 add_timer (&flashcard_timer);
 293                                 return ret;
 294                         }
 295                 }
 296
 297         }
 298
 299         writew(IF_READ_ARRAY, (u_long)pageaddr & ~1);
 300
 301         ret = 0;
 302         memcpy (buf, pageaddr, *retlen);
 303
 304         writew(IF_READ_CSR, (u_long)pageaddr & ~1);
 305
 306
 307         if (priv->devstat[device] & MTD_ERASE_SUSPEND)
 308         {
 309                 resume_erase(pageaddr);
 310                 priv->devstat[device]=MTD_ERASING;
 311         }
 312
 313
 314         if (timeron) add_timer (&flashcard_timer);
 315
 316         return ret;
 317 }
 318
 319
 320 int flashcard_write (struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf)
 321 {
 322         struct mypriv *priv = (struct mypriv *)mtd->priv;
 323         u_char *endaddr, *startaddr;
 324         register u_char *pageaddr;
 325         u_char device = to >> priv->devshift;
 326 /*      jiffies_t oldj=jiffies;*/
 327         int ret;
 328
 329         while (priv->devstat[device])
 330         {
 331                 flashcard_sync(mtd);
 332         }
 333
 334         if ((to & WINDOW_MASK) + len <= WINDOW_SIZE)
 335                 *retlen = len;
 336         else
 337                 *retlen = WINDOW_SIZE - (to & WINDOW_MASK);
 338
 339         pageaddr = pagein(mtd, to);
 340         startaddr = (u_char *)((u_long) pageaddr & ~1);
 341         endaddr = pageaddr+(*retlen);
 342
 343
 344
 345         /* Set up to read */
 346         writew(IF_READ_CSR, startaddr);
 347
 348         /* Make sure it's aligned by reading the first byte if necessary */
 349         if (to & 1)
 350         {
 351                 /* Unaligned access */
 352
 353                 u_char cbuf;
 354
 355                 cbuf = *buf;
 356
 357                 if (!((u_long)pageaddr & 0xf))
 358                         schedule();
 359
 360                 ret = byte_write(pageaddr, cbuf);
 361                 if (ret) return ret;
 362
 363                 pageaddr++; buf++;
 364         }
 365
 366
 367         for ( ; pageaddr + 1 < endaddr; buf += 2, pageaddr += 2)
 368                 {
 369                         /* if ((u_long)pageaddr & 0xf) schedule();*/
 370
 371                         ret = word_write(pageaddr, *(__u16 *)buf);
 372                         if (ret)
 373                                 return ret;
 374                 }
 375
 376         if (pageaddr != endaddr)
 377         {
 378                 /* One more byte to write at the end. */
 379                 u_char cbuf;
 380
 381                 cbuf = *buf;
 382
 383                 ret = byte_write(pageaddr, cbuf);
 384
 385                 if (ret) return ret;
 386         }
 387
 388         return check_write(startaddr);
 389 /*      printk("Time taken in flashcard_write: %lx jiffies\n",jiffies - oldj);*/
 390 }
 391
 392
 393
 394
 395 /*====================================================================*/
 396
 397 static inline void block_erase (volatile u_char *addr)
 398 {
 399         writew(IF_BLOCK_ERASE, addr);
 400         writew(IF_CONFIRM, addr);
 401 }
 402
 403
 404 static inline int check_erase(volatile u_char *addr)
 405 {
 406         __u16 status;
 407
 408 /*      writew(IF_READ_CSR, addr);*/
 409         status = readw(addr);
 410
 411
 412         if ((status & CSR_WR_READY) != CSR_WR_READY)
 413                 return -EBUSY;
 414
 415         if (status & (CSR_ERA_ERR | CSR_VPP_LOW | CSR_WR_ERR))
 416         {
 417                 printk(KERN_NOTICE "flashcard: erase failed, status 0x%x\n",
 418                        status);
 419                 return -EIO;
 420         }
 421
 422         return 0;
 423 }
 424
 425 /*====================================================================*/
 426
 427
 428
 429 static void flashcard_periodic(unsigned long data)
 430 {
 431         register struct mtd_info *mtd = (struct mtd_info *)data;
 432         register struct mypriv *priv = mtd->priv;
 433         struct erase_info *erase = priv->cur_erases;
 434         u_char *pageaddr;
 435
 436         del_timer (&flashcard_timer);
 437
 438         if (!erase)
 439                 return;
 440
 441         pageaddr = pagein(mtd, erase->addr);
 442
 443         if (erase->state == MTD_ERASE_PENDING)
 444         {
 445                 block_erase(pageaddr);
 446                 priv->devstat[erase->dev] = erase->state = MTD_ERASING;
 447                 erase->time = jiffies;
 448                 erase->retries = 0;
 449         }
 450         else if (erase->state == MTD_ERASING)
 451         {
 452                 /* It's trying to erase. Check whether it's finished */
 453
 454                 int ret = check_erase(pageaddr);
 455
 456                 if (!ret)
 457                 {
 458                         /* It's finished OK */
 459                         priv->devstat[erase->dev] = 0;
 460                         priv->cur_erases = erase->next;
 461                         erase->state = MTD_ERASE_DONE;
 462                         if (erase->callback)
 463                                 (*(erase->callback))(erase);
 464                         else
 465                                 kfree(erase);
 466                 }
 467                 else if (ret == -EIO)
 468                 {
 469                         if (++erase->retries > retry_limit)
 470                         {
 471                                 printk("Failed too many times. Giving up\n");
 472                                 priv->cur_erases = erase->next;
 473                                 priv->devstat[erase->dev] = 0;
 474                                 erase->state = MTD_ERASE_FAILED;
 475                                 if (erase->callback)
 476                                         (*(erase->callback))(erase);
 477                                 else
 478                                         kfree(erase);
 479                         }
 480                         else
 481                                 priv->devstat[erase->dev] = erase->state = MTD_ERASE_PENDING;
 482                 }
 483                 else if (time_after(jiffies, erase->time + erase_timeout))
 484                 {
 485                         printk("Flash erase timed out. The world is broken.\n");
 486
 487                         /* Just ignore and hope it goes away. For a while, read ops will give the CSR
 488                            and writes won't work. */
 489
 490                         priv->cur_erases = erase->next;
 491                         priv->devstat[erase->dev] = 0;
 492                         erase->state = MTD_ERASE_FAILED;
 493                         if (erase->callback)
 494                                         (*(erase->callback))(erase);
 495                                 else
 496                                         kfree(erase);
 497                 }
 498         }
 499
 500         if (priv->cur_erases)
 501         {
 502                 flashcard_timer.expires = jiffies + HZ;
 503                 add_timer (&flashcard_timer);
 504         }
 505         else
 506                 wake_up_interruptible(&priv->wq);
 507
 508 }
 509
 510 int __init init_doc1000(void)
 511 {
 512         struct mypriv *priv;
 513
 514         if (!base)
 515         {
 516                 printk(KERN_NOTICE "flashcard: No start address for memory device.\n");
 517                 return -EINVAL;
 518         }
 519
 520         mymtd  = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
 521
 522         if (!mymtd)
 523         {
 524                 printk(KERN_NOTICE "physmem: Cannot allocate memory for new MTD device.\n");
 525                 return -ENOMEM;
 526         }
 527
 528         memset(mymtd,0,sizeof(struct mtd_info));
 529
 530         mymtd->priv = (void *) kmalloc (sizeof(struct mypriv), GFP_KERNEL);
 531         if (!mymtd->priv)
 532           {
 533             kfree(mymtd);
 534             printk(KERN_NOTICE "physmem: Cannot allocate memory for new MTD device's private data.\n");
 535             return -ENOMEM;
 536           }
 537
 538
 539
 540
 541         priv=mymtd->priv;
 542         init_waitqueue_head(&priv->wq);
 543
 544         memset (priv,0,sizeof(struct mypriv));
 545
 546         priv->baseaddr = phys_to_virt(base);
 547         priv->numdevices = 4;
 548
 549         mymtd->name = "M-Systems DiskOnChip 1000";
 550
 551         mymtd->size = 0x100000;
 552         mymtd->flags = MTD_CLEAR_BITS | MTD_ERASEABLE;
 553         mymtd->erase = flashcard_erase;
 554         mymtd->point = NULL;
 555         mymtd->unpoint = NULL;
 556         mymtd->read = flashcard_read;
 557         mymtd->write = flashcard_write;
 558
 559         mymtd->sync = flashcard_sync;
 560         mymtd->erasesize = 0x10000;
 561         //      mymtd->interleave = 2;
 562         priv->devshift =  24;
 563         mymtd->type = MTD_NORFLASH;
 564
 565         if (add_mtd_device(mymtd))
 566         {
 567                 printk(KERN_NOTICE "MTD device registration failed!\n");
 568                 kfree(mymtd->priv);
 569                 kfree(mymtd);
 570                 return -EAGAIN;
 571         }
 572
 573         init_timer(&flashcard_timer);
 574         flashcard_timer.function = flashcard_periodic;
 575         flashcard_timer.data = (u_long)mymtd;
 576         return 0;
 577 }
 578
 579 static void __init cleanup_doc1000(void)
 580 {
 581         kfree (mymtd->priv);
 582         del_mtd_device(mymtd);
 583         kfree(mymtd);
 584 }
 585
 586 module_init(init_doc1000);
 587 module_exit(cleanup_doc1000);
 588
 589 MODULE_LICENSE("GPL");
 590 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
 591 MODULE_DESCRIPTION("MTD driver for DiskOnChip 1000");
 592