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   1 /*
   2  *  linux/drivers/mtd/onenand/onenand_sim.c
   3  *
   4  *  The OneNAND simulator
   5  *
   6  *  Copyright © 2005-2007 Samsung Electronics
   7  *  Kyungmin Park <kyungmin.park@samsung.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/mtd/mtd.h>
  19 #include <linux/mtd/partitions.h>
  20 #include <linux/mtd/onenand.h>
  21
  22 #include <linux/io.h>
  23
  24 #ifndef CONFIG_ONENAND_SIM_MANUFACTURER
  25 #define CONFIG_ONENAND_SIM_MANUFACTURER         0xec
  26 #endif
  27 #ifndef CONFIG_ONENAND_SIM_DEVICE_ID
  28 #define CONFIG_ONENAND_SIM_DEVICE_ID            0x04
  29 #endif
  30 #ifndef CONFIG_ONENAND_SIM_VERSION_ID
  31 #define CONFIG_ONENAND_SIM_VERSION_ID           0x1e
  32 #endif
  33
  34 static int manuf_id     = CONFIG_ONENAND_SIM_MANUFACTURER;
  35 static int device_id    = CONFIG_ONENAND_SIM_DEVICE_ID;
  36 static int version_id   = CONFIG_ONENAND_SIM_VERSION_ID;
  37
  38 struct onenand_flash {
  39         void __iomem *base;
  40         void __iomem *data;
  41 };
  42
  43 #define ONENAND_CORE(flash)             (flash->data)
  44 #define ONENAND_CORE_SPARE(flash, this, offset)                         \
  45         ((flash->data) + (this->chipsize) + (offset >> 5))
  46
  47 #define ONENAND_MAIN_AREA(this, offset)                                 \
  48         (this->base + ONENAND_DATARAM + offset)
  49
  50 #define ONENAND_SPARE_AREA(this, offset)                                \
  51         (this->base + ONENAND_SPARERAM + offset)
  52
  53 #define ONENAND_GET_WP_STATUS(this)                                     \
  54         (readw(this->base + ONENAND_REG_WP_STATUS))
  55
  56 #define ONENAND_SET_WP_STATUS(v, this)                                  \
  57         (writew(v, this->base + ONENAND_REG_WP_STATUS))
  58
  59 /* It has all 0xff chars */
  60 #define MAX_ONENAND_PAGESIZE            (2048 + 64)
  61 static unsigned char *ffchars;
  62
  63 static struct mtd_partition os_partitions[] = {
  64         {
  65                 .name           = "OneNAND simulator partition",
  66                 .offset         = 0,
  67                 .size           = MTDPART_SIZ_FULL,
  68         },
  69 };
  70
  71 /*
  72  * OneNAND simulator mtd
  73  */
  74 struct onenand_info {
  75         struct mtd_info         mtd;
  76         struct mtd_partition    *parts;
  77         struct onenand_chip     onenand;
  78         struct onenand_flash    flash;
  79 };
  80
  81 static struct onenand_info *info;
  82
  83 #define DPRINTK(format, args...)                                        \
  84 do {                                                                    \
  85         printk(KERN_DEBUG "%s[%d]: " format "\n", __func__,             \
  86                            __LINE__, ##args);                           \
  87 } while (0)
  88
  89 /**
  90  * onenand_lock_handle - Handle Lock scheme
  91  * @this:               OneNAND device structure
  92  * @cmd:                The command to be sent
  93  *
  94  * Send lock command to OneNAND device.
  95  * The lock scheme depends on chip type.
  96  */
  97 static void onenand_lock_handle(struct onenand_chip *this, int cmd)
  98 {
  99         int block_lock_scheme;
 100         int status;
 101
 102         status = ONENAND_GET_WP_STATUS(this);
 103         block_lock_scheme = !(this->options & ONENAND_HAS_CONT_LOCK);
 104
 105         switch (cmd) {
 106         case ONENAND_CMD_UNLOCK:
 107                 if (block_lock_scheme)
 108                         ONENAND_SET_WP_STATUS(ONENAND_WP_US, this);
 109                 else
 110                         ONENAND_SET_WP_STATUS(status | ONENAND_WP_US, this);
 111                 break;
 112
 113         case ONENAND_CMD_LOCK:
 114                 if (block_lock_scheme)
 115                         ONENAND_SET_WP_STATUS(ONENAND_WP_LS, this);
 116                 else
 117                         ONENAND_SET_WP_STATUS(status | ONENAND_WP_LS, this);
 118                 break;
 119
 120         case ONENAND_CMD_LOCK_TIGHT:
 121                 if (block_lock_scheme)
 122                         ONENAND_SET_WP_STATUS(ONENAND_WP_LTS, this);
 123                 else
 124                         ONENAND_SET_WP_STATUS(status | ONENAND_WP_LTS, this);
 125                 break;
 126
 127         default:
 128                 break;
 129         }
 130 }
 131
 132 /**
 133  * onenand_bootram_handle - Handle BootRAM area
 134  * @this:               OneNAND device structure
 135  * @cmd:                The command to be sent
 136  *
 137  * Emulate BootRAM area. It is possible to do basic operation using BootRAM.
 138  */
 139 static void onenand_bootram_handle(struct onenand_chip *this, int cmd)
 140 {
 141         switch (cmd) {
 142         case ONENAND_CMD_READID:
 143                 writew(manuf_id, this->base);
 144                 writew(device_id, this->base + 2);
 145                 writew(version_id, this->base + 4);
 146                 break;
 147
 148         default:
 149                 /* REVIST: Handle other commands */
 150                 break;
 151         }
 152 }
 153
 154 /**
 155  * onenand_update_interrupt - Set interrupt register
 156  * @this:         OneNAND device structure
 157  * @cmd:          The command to be sent
 158  *
 159  * Update interrupt register. The status depends on command.
 160  */
 161 static void onenand_update_interrupt(struct onenand_chip *this, int cmd)
 162 {
 163         int interrupt = ONENAND_INT_MASTER;
 164
 165         switch (cmd) {
 166         case ONENAND_CMD_READ:
 167         case ONENAND_CMD_READOOB:
 168                 interrupt |= ONENAND_INT_READ;
 169                 break;
 170
 171         case ONENAND_CMD_PROG:
 172         case ONENAND_CMD_PROGOOB:
 173                 interrupt |= ONENAND_INT_WRITE;
 174                 break;
 175
 176         case ONENAND_CMD_ERASE:
 177                 interrupt |= ONENAND_INT_ERASE;
 178                 break;
 179
 180         case ONENAND_CMD_RESET:
 181                 interrupt |= ONENAND_INT_RESET;
 182                 break;
 183
 184         default:
 185                 break;
 186         }
 187
 188         writew(interrupt, this->base + ONENAND_REG_INTERRUPT);
 189 }
 190
 191 /**
 192  * onenand_check_overwrite - Check if over-write happened
 193  * @dest:               The destination pointer
 194  * @src:                The source pointer
 195  * @count:              The length to be check
 196  *
 197  * Returns:             0 on same, otherwise 1
 198  *
 199  * Compare the source with destination
 200  */
 201 static int onenand_check_overwrite(void *dest, void *src, size_t count)
 202 {
 203         unsigned int *s = (unsigned int *) src;
 204         unsigned int *d = (unsigned int *) dest;
 205         int i;
 206
 207         count >>= 2;
 208         for (i = 0; i < count; i++)
 209                 if ((*s++ ^ *d++) != 0)
 210                         return 1;
 211
 212         return 0;
 213 }
 214
 215 /**
 216  * onenand_data_handle - Handle OneNAND Core and DataRAM
 217  * @this:               OneNAND device structure
 218  * @cmd:                The command to be sent
 219  * @dataram:            Which dataram used
 220  * @offset:             The offset to OneNAND Core
 221  *
 222  * Copy data from OneNAND Core to DataRAM (read)
 223  * Copy data from DataRAM to OneNAND Core (write)
 224  * Erase the OneNAND Core (erase)
 225  */
 226 static void onenand_data_handle(struct onenand_chip *this, int cmd,
 227                                 int dataram, unsigned int offset)
 228 {
 229         struct mtd_info *mtd = &info->mtd;
 230         struct onenand_flash *flash = this->priv;
 231         int main_offset, spare_offset;
 232         void __iomem *src;
 233         void __iomem *dest;
 234         unsigned int i;
 235
 236         if (dataram) {
 237                 main_offset = mtd->writesize;
 238                 spare_offset = mtd->oobsize;
 239         } else {
 240                 main_offset = 0;
 241                 spare_offset = 0;
 242         }
 243
 244         switch (cmd) {
 245         case ONENAND_CMD_READ:
 246                 src = ONENAND_CORE(flash) + offset;
 247                 dest = ONENAND_MAIN_AREA(this, main_offset);
 248                 memcpy(dest, src, mtd->writesize);
 249                 /* Fall through */
 250
 251         case ONENAND_CMD_READOOB:
 252                 src = ONENAND_CORE_SPARE(flash, this, offset);
 253                 dest = ONENAND_SPARE_AREA(this, spare_offset);
 254                 memcpy(dest, src, mtd->oobsize);
 255                 break;
 256
 257         case ONENAND_CMD_PROG:
 258                 src = ONENAND_MAIN_AREA(this, main_offset);
 259                 dest = ONENAND_CORE(flash) + offset;
 260                 /* To handle partial write */
 261                 for (i = 0; i < (1 << mtd->subpage_sft); i++) {
 262                         int off = i * this->subpagesize;
 263                         if (!memcmp(src + off, ffchars, this->subpagesize))
 264                                 continue;
 265                         if (memcmp(dest + off, ffchars, this->subpagesize) &&
 266                             onenand_check_overwrite(dest + off, src + off, this->subpagesize))
 267                                 printk(KERN_ERR "over-write happend at 0x%08x\n", offset);
 268                         memcpy(dest + off, src + off, this->subpagesize);
 269                 }
 270                 /* Fall through */
 271
 272         case ONENAND_CMD_PROGOOB:
 273                 src = ONENAND_SPARE_AREA(this, spare_offset);
 274                 /* Check all data is 0xff chars */
 275                 if (!memcmp(src, ffchars, mtd->oobsize))
 276                         break;
 277
 278                 dest = ONENAND_CORE_SPARE(flash, this, offset);
 279                 if (memcmp(dest, ffchars, mtd->oobsize) &&
 280                     onenand_check_overwrite(dest, src, mtd->oobsize))
 281                         printk(KERN_ERR "OOB: over-write happend at 0x%08x\n",
 282                                offset);
 283                 memcpy(dest, src, mtd->oobsize);
 284                 break;
 285
 286         case ONENAND_CMD_ERASE:
 287                 memset(ONENAND_CORE(flash) + offset, 0xff, mtd->erasesize);
 288                 memset(ONENAND_CORE_SPARE(flash, this, offset), 0xff,
 289                        (mtd->erasesize >> 5));
 290                 break;
 291
 292         default:
 293                 break;
 294         }
 295 }
 296
 297 /**
 298  * onenand_command_handle - Handle command
 299  * @this:               OneNAND device structure
 300  * @cmd:                The command to be sent
 301  *
 302  * Emulate OneNAND command.
 303  */
 304 static void onenand_command_handle(struct onenand_chip *this, int cmd)
 305 {
 306         unsigned long offset = 0;
 307         int block = -1, page = -1, bufferram = -1;
 308         int dataram = 0;
 309
 310         switch (cmd) {
 311         case ONENAND_CMD_UNLOCK:
 312         case ONENAND_CMD_LOCK:
 313         case ONENAND_CMD_LOCK_TIGHT:
 314         case ONENAND_CMD_UNLOCK_ALL:
 315                 onenand_lock_handle(this, cmd);
 316                 break;
 317
 318         case ONENAND_CMD_BUFFERRAM:
 319                 /* Do nothing */
 320                 return;
 321
 322         default:
 323                 block = (int) readw(this->base + ONENAND_REG_START_ADDRESS1);
 324                 if (block & (1 << ONENAND_DDP_SHIFT)) {
 325                         block &= ~(1 << ONENAND_DDP_SHIFT);
 326                         /* The half of chip block */
 327                         block += this->chipsize >> (this->erase_shift + 1);
 328                 }
 329                 if (cmd == ONENAND_CMD_ERASE)
 330                         break;
 331
 332                 page = (int) readw(this->base + ONENAND_REG_START_ADDRESS8);
 333                 page = (page >> ONENAND_FPA_SHIFT);
 334                 bufferram = (int) readw(this->base + ONENAND_REG_START_BUFFER);
 335                 bufferram >>= ONENAND_BSA_SHIFT;
 336                 bufferram &= ONENAND_BSA_DATARAM1;
 337                 dataram = (bufferram == ONENAND_BSA_DATARAM1) ? 1 : 0;
 338                 break;
 339         }
 340
 341         if (block != -1)
 342                 offset += block << this->erase_shift;
 343
 344         if (page != -1)
 345                 offset += page << this->page_shift;
 346
 347         onenand_data_handle(this, cmd, dataram, offset);
 348
 349         onenand_update_interrupt(this, cmd);
 350 }
 351
 352 /**
 353  * onenand_writew - [OneNAND Interface] Emulate write operation
 354  * @value:              value to write
 355  * @addr:               address to write
 356  *
 357  * Write OneNAND register with value
 358  */
 359 static void onenand_writew(unsigned short value, void __iomem * addr)
 360 {
 361         struct onenand_chip *this = info->mtd.priv;
 362
 363         /* BootRAM handling */
 364         if (addr < this->base + ONENAND_DATARAM) {
 365                 onenand_bootram_handle(this, value);
 366                 return;
 367         }
 368         /* Command handling */
 369         if (addr == this->base + ONENAND_REG_COMMAND)
 370                 onenand_command_handle(this, value);
 371
 372         writew(value, addr);
 373 }
 374
 375 /**
 376  * flash_init - Initialize OneNAND simulator
 377  * @flash:              OneNAND simulator data strucutres
 378  *
 379  * Initialize OneNAND simulator.
 380  */
 381 static int __init flash_init(struct onenand_flash *flash)
 382 {
 383         int density, size;
 384         int buffer_size;
 385
 386         flash->base = kzalloc(131072, GFP_KERNEL);
 387         if (!flash->base) {
 388                 printk(KERN_ERR "Unable to allocate base address.\n");
 389                 return -ENOMEM;
 390         }
 391
 392         density = device_id >> ONENAND_DEVICE_DENSITY_SHIFT;
 393         size = ((16 << 20) << density);
 394
 395         ONENAND_CORE(flash) = vmalloc(size + (size >> 5));
 396         if (!ONENAND_CORE(flash)) {
 397                 printk(KERN_ERR "Unable to allocate nand core address.\n");
 398                 kfree(flash->base);
 399                 return -ENOMEM;
 400         }
 401
 402         memset(ONENAND_CORE(flash), 0xff, size + (size >> 5));
 403
 404         /* Setup registers */
 405         writew(manuf_id, flash->base + ONENAND_REG_MANUFACTURER_ID);
 406         writew(device_id, flash->base + ONENAND_REG_DEVICE_ID);
 407         writew(version_id, flash->base + ONENAND_REG_VERSION_ID);
 408
 409         if (density < 2)
 410                 buffer_size = 0x0400;   /* 1KiB page */
 411         else
 412                 buffer_size = 0x0800;   /* 2KiB page */
 413         writew(buffer_size, flash->base + ONENAND_REG_DATA_BUFFER_SIZE);
 414
 415         return 0;
 416 }
 417
 418 /**
 419  * flash_exit - Clean up OneNAND simulator
 420  * @flash:              OneNAND simulator data structures
 421  *
 422  * Clean up OneNAND simulator.
 423  */
 424 static void flash_exit(struct onenand_flash *flash)
 425 {
 426         vfree(ONENAND_CORE(flash));
 427         kfree(flash->base);
 428 }
 429
 430 static int __init onenand_sim_init(void)
 431 {
 432         /* Allocate all 0xff chars pointer */
 433         ffchars = kmalloc(MAX_ONENAND_PAGESIZE, GFP_KERNEL);
 434         if (!ffchars) {
 435                 printk(KERN_ERR "Unable to allocate ff chars.\n");
 436                 return -ENOMEM;
 437         }
 438         memset(ffchars, 0xff, MAX_ONENAND_PAGESIZE);
 439
 440         /* Allocate OneNAND simulator mtd pointer */
 441         info = kzalloc(sizeof(struct onenand_info), GFP_KERNEL);
 442         if (!info) {
 443                 printk(KERN_ERR "Unable to allocate core structures.\n");
 444                 kfree(ffchars);
 445                 return -ENOMEM;
 446         }
 447
 448         /* Override write_word function */
 449         info->onenand.write_word = onenand_writew;
 450
 451         if (flash_init(&info->flash)) {
 452                 printk(KERN_ERR "Unable to allocate flash.\n");
 453                 kfree(ffchars);
 454                 kfree(info);
 455                 return -ENOMEM;
 456         }
 457
 458         info->parts = os_partitions;
 459
 460         info->onenand.base = info->flash.base;
 461         info->onenand.priv = &info->flash;
 462
 463         info->mtd.name = "OneNAND simulator";
 464         info->mtd.priv = &info->onenand;
 465         info->mtd.owner = THIS_MODULE;
 466
 467         if (onenand_scan(&info->mtd, 1)) {
 468                 flash_exit(&info->flash);
 469                 kfree(ffchars);
 470                 kfree(info);
 471                 return -ENXIO;
 472         }
 473
 474         add_mtd_partitions(&info->mtd, info->parts, ARRAY_SIZE(os_partitions));
 475
 476         return 0;
 477 }
 478
 479 static void __exit onenand_sim_exit(void)
 480 {
 481         struct onenand_chip *this = info->mtd.priv;
 482         struct onenand_flash *flash = this->priv;
 483
 484         onenand_release(&info->mtd);
 485         flash_exit(flash);
 486         kfree(ffchars);
 487         kfree(info);
 488 }
 489
 490 module_init(onenand_sim_init);
 491 module_exit(onenand_sim_exit);
 492
 493 MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
 494 MODULE_DESCRIPTION("The OneNAND flash simulator");
 495 MODULE_LICENSE("GPL");