target/linux/olpc/files-2.6.23/drivers/mtd/onenand/onenand_sim.c

   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 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  * @param this          OneNAND device structure
  92  * @param cmd           The command to be sent
  93  *
  94  * Send lock command to OneNAND device.
  95  * The lock scheme is 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  * @param this          OneNAND device structure
 135  * @param 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  * @param this         OneNAND device structure
 157  * @param cmd          The command to be sent
 158  *
 159  * Update interrupt register. The status is 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 over-write if happend
 193  * @param dest          The destination pointer
 194  * @param src           The source pointer
 195  * @param count         The length to be check
 196  * @return              0 on same, otherwise 1
 197  *
 198  * Compare the source with destination
 199  */
 200 static int onenand_check_overwrite(void *dest, void *src, size_t count)
 201 {
 202         unsigned int *s = (unsigned int *) src;
 203         unsigned int *d = (unsigned int *) dest;
 204         int i;
 205
 206         count >>= 2;
 207         for (i = 0; i < count; i++)
 208                 if ((*s++ ^ *d++) != 0)
 209                         return 1;
 210
 211         return 0;
 212 }
 213
 214 /**
 215  * onenand_data_handle - Handle OneNAND Core and DataRAM
 216  * @param this          OneNAND device structure
 217  * @param cmd           The command to be sent
 218  * @param dataram       Which dataram used
 219  * @param offset        The offset to OneNAND Core
 220  *
 221  * Copy data from OneNAND Core to DataRAM (read)
 222  * Copy data from DataRAM to OneNAND Core (write)
 223  * Erase the OneNAND Core (erase)
 224  */
 225 static void onenand_data_handle(struct onenand_chip *this, int cmd,
 226                                 int dataram, unsigned int offset)
 227 {
 228         struct mtd_info *mtd = &info->mtd;
 229         struct onenand_flash *flash = this->priv;
 230         int main_offset, spare_offset;
 231         void __iomem *src;
 232         void __iomem *dest;
 233         unsigned int i;
 234
 235         if (dataram) {
 236                 main_offset = mtd->writesize;
 237                 spare_offset = mtd->oobsize;
 238         } else {
 239                 main_offset = 0;
 240                 spare_offset = 0;
 241         }
 242
 243         switch (cmd) {
 244         case ONENAND_CMD_READ:
 245                 src = ONENAND_CORE(flash) + offset;
 246                 dest = ONENAND_MAIN_AREA(this, main_offset);
 247                 memcpy(dest, src, mtd->writesize);
 248                 /* Fall through */
 249
 250         case ONENAND_CMD_READOOB:
 251                 src = ONENAND_CORE_SPARE(flash, this, offset);
 252                 dest = ONENAND_SPARE_AREA(this, spare_offset);
 253                 memcpy(dest, src, mtd->oobsize);
 254                 break;
 255
 256         case ONENAND_CMD_PROG:
 257                 src = ONENAND_MAIN_AREA(this, main_offset);
 258                 dest = ONENAND_CORE(flash) + offset;
 259                 /* To handle partial write */
 260                 for (i = 0; i < (1 << mtd->subpage_sft); i++) {
 261                         int off = i * this->subpagesize;
 262                         if (!memcmp(src + off, ffchars, this->subpagesize))
 263                                 continue;
 264                         if (memcmp(dest + off, ffchars, this->subpagesize) &&
 265                             onenand_check_overwrite(dest + off, src + off, this->subpagesize))
 266                                 printk(KERN_ERR "over-write happend at 0x%08x\n", offset);
 267                         memcpy(dest + off, src + off, this->subpagesize);
 268                 }
 269                 /* Fall through */
 270
 271         case ONENAND_CMD_PROGOOB:
 272                 src = ONENAND_SPARE_AREA(this, spare_offset);
 273                 /* Check all data is 0xff chars */
 274                 if (!memcmp(src, ffchars, mtd->oobsize))
 275                         break;
 276
 277                 dest = ONENAND_CORE_SPARE(flash, this, offset);
 278                 if (memcmp(dest, ffchars, mtd->oobsize) &&
 279                     onenand_check_overwrite(dest, src, mtd->oobsize))
 280                         printk(KERN_ERR "OOB: over-write happend at 0x%08x\n",
 281                                offset);
 282                 memcpy(dest, src, mtd->oobsize);
 283                 break;
 284
 285         case ONENAND_CMD_ERASE:
 286                 memset(ONENAND_CORE(flash) + offset, 0xff, mtd->erasesize);
 287                 memset(ONENAND_CORE_SPARE(flash, this, offset), 0xff,
 288                        (mtd->erasesize >> 5));
 289                 break;
 290
 291         default:
 292                 break;
 293         }
 294 }
 295
 296 /**
 297  * onenand_command_handle - Handle command
 298  * @param this          OneNAND device structure
 299  * @param cmd           The command to be sent
 300  *
 301  * Emulate OneNAND command.
 302  */
 303 static void onenand_command_handle(struct onenand_chip *this, int cmd)
 304 {
 305         unsigned long offset = 0;
 306         int block = -1, page = -1, bufferram = -1;
 307         int dataram = 0;
 308
 309         switch (cmd) {
 310         case ONENAND_CMD_UNLOCK:
 311         case ONENAND_CMD_LOCK:
 312         case ONENAND_CMD_LOCK_TIGHT:
 313         case ONENAND_CMD_UNLOCK_ALL:
 314                 onenand_lock_handle(this, cmd);
 315                 break;
 316
 317         case ONENAND_CMD_BUFFERRAM:
 318                 /* Do nothing */
 319                 return;
 320
 321         default:
 322                 block = (int) readw(this->base + ONENAND_REG_START_ADDRESS1);
 323                 if (block & (1 << ONENAND_DDP_SHIFT)) {
 324                         block &= ~(1 << ONENAND_DDP_SHIFT);
 325                         /* The half of chip block */
 326                         block += this->chipsize >> (this->erase_shift + 1);
 327                 }
 328                 if (cmd == ONENAND_CMD_ERASE)
 329                         break;
 330
 331                 page = (int) readw(this->base + ONENAND_REG_START_ADDRESS8);
 332                 page = (page >> ONENAND_FPA_SHIFT);
 333                 bufferram = (int) readw(this->base + ONENAND_REG_START_BUFFER);
 334                 bufferram >>= ONENAND_BSA_SHIFT;
 335                 bufferram &= ONENAND_BSA_DATARAM1;
 336                 dataram = (bufferram == ONENAND_BSA_DATARAM1) ? 1 : 0;
 337                 break;
 338         }
 339
 340         if (block != -1)
 341                 offset += block << this->erase_shift;
 342
 343         if (page != -1)
 344                 offset += page << this->page_shift;
 345
 346         onenand_data_handle(this, cmd, dataram, offset);
 347
 348         onenand_update_interrupt(this, cmd);
 349 }
 350
 351 /**
 352  * onenand_writew - [OneNAND Interface] Emulate write operation
 353  * @param value         value to write
 354  * @param addr          address to write
 355  *
 356  * Write OneNAND register with value
 357  */
 358 static void onenand_writew(unsigned short value, void __iomem * addr)
 359 {
 360         struct onenand_chip *this = info->mtd.priv;
 361
 362         /* BootRAM handling */
 363         if (addr < this->base + ONENAND_DATARAM) {
 364                 onenand_bootram_handle(this, value);
 365                 return;
 366         }
 367         /* Command handling */
 368         if (addr == this->base + ONENAND_REG_COMMAND)
 369                 onenand_command_handle(this, value);
 370
 371         writew(value, addr);
 372 }
 373
 374 /**
 375  * flash_init - Initialize OneNAND simulator
 376  * @param flash         OneNAND simulaotr data strucutres
 377  *
 378  * Initialize OneNAND simulator.
 379  */
 380 static int __init flash_init(struct onenand_flash *flash)
 381 {
 382         int density, size;
 383         int buffer_size;
 384
 385         flash->base = kzalloc(131072, GFP_KERNEL);
 386         if (!flash->base) {
 387                 printk(KERN_ERR "Unable to allocate base address.\n");
 388                 return -ENOMEM;
 389         }
 390
 391         density = device_id >> ONENAND_DEVICE_DENSITY_SHIFT;
 392         size = ((16 << 20) << density);
 393
 394         ONENAND_CORE(flash) = vmalloc(size + (size >> 5));
 395         if (!ONENAND_CORE(flash)) {
 396                 printk(KERN_ERR "Unable to allocate nand core address.\n");
 397                 kfree(flash->base);
 398                 return -ENOMEM;
 399         }
 400
 401         memset(ONENAND_CORE(flash), 0xff, size + (size >> 5));
 402
 403         /* Setup registers */
 404         writew(manuf_id, flash->base + ONENAND_REG_MANUFACTURER_ID);
 405         writew(device_id, flash->base + ONENAND_REG_DEVICE_ID);
 406         writew(version_id, flash->base + ONENAND_REG_VERSION_ID);
 407
 408         if (density < 2)
 409                 buffer_size = 0x0400;   /* 1KiB page */
 410         else
 411                 buffer_size = 0x0800;   /* 2KiB page */
 412         writew(buffer_size, flash->base + ONENAND_REG_DATA_BUFFER_SIZE);
 413
 414         return 0;
 415 }
 416
 417 /**
 418  * flash_exit - Clean up OneNAND simulator
 419  * @param flash         OneNAND simulaotr data strucutres
 420  *
 421  * Clean up OneNAND simulator.
 422  */
 423 static void flash_exit(struct onenand_flash *flash)
 424 {
 425         vfree(ONENAND_CORE(flash));
 426         kfree(flash->base);
 427         kfree(flash);
 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 allocat 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");