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   1 /*
   2  * NAND flash simulator.
   3  *
   4  * Author: Artem B. Bityuckiy <dedekind@oktetlabs.ru>, <dedekind@infradead.org>
   5  *
   6  * Copyright (C) 2004 Nokia Corporation
   7  *
   8  * Note: NS means "NAND Simulator".
   9  * Note: Input means input TO flash chip, output means output FROM chip.
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the
  13  * Free Software Foundation; either version 2, or (at your option) any later
  14  * version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  19  * Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
  24  *
  25  * $Id: nandsim.c,v 1.8 2005/03/19 15:33:56 dedekind Exp $
  26  */
  27
  28 #include <linux/init.h>
  29 #include <linux/types.h>
  30 #include <linux/module.h>
  31 #include <linux/moduleparam.h>
  32 #include <linux/vmalloc.h>
  33 #include <linux/slab.h>
  34 #include <linux/errno.h>
  35 #include <linux/string.h>
  36 #include <linux/mtd/mtd.h>
  37 #include <linux/mtd/nand.h>
  38 #include <linux/mtd/partitions.h>
  39 #include <linux/delay.h>
  40 #ifdef CONFIG_NS_ABS_POS
  41 #include <asm/io.h>
  42 #endif
  43
  44
  45 /* Default simulator parameters values */
  46 #if !defined(CONFIG_NANDSIM_FIRST_ID_BYTE)  || \
  47     !defined(CONFIG_NANDSIM_SECOND_ID_BYTE) || \
  48     !defined(CONFIG_NANDSIM_THIRD_ID_BYTE)  || \
  49     !defined(CONFIG_NANDSIM_FOURTH_ID_BYTE)
  50 #define CONFIG_NANDSIM_FIRST_ID_BYTE  0x98
  51 #define CONFIG_NANDSIM_SECOND_ID_BYTE 0x39
  52 #define CONFIG_NANDSIM_THIRD_ID_BYTE  0xFF /* No byte */
  53 #define CONFIG_NANDSIM_FOURTH_ID_BYTE 0xFF /* No byte */
  54 #endif
  55
  56 #ifndef CONFIG_NANDSIM_ACCESS_DELAY
  57 #define CONFIG_NANDSIM_ACCESS_DELAY 25
  58 #endif
  59 #ifndef CONFIG_NANDSIM_PROGRAMM_DELAY
  60 #define CONFIG_NANDSIM_PROGRAMM_DELAY 200
  61 #endif
  62 #ifndef CONFIG_NANDSIM_ERASE_DELAY
  63 #define CONFIG_NANDSIM_ERASE_DELAY 2
  64 #endif
  65 #ifndef CONFIG_NANDSIM_OUTPUT_CYCLE
  66 #define CONFIG_NANDSIM_OUTPUT_CYCLE 40
  67 #endif
  68 #ifndef CONFIG_NANDSIM_INPUT_CYCLE
  69 #define CONFIG_NANDSIM_INPUT_CYCLE  50
  70 #endif
  71 #ifndef CONFIG_NANDSIM_BUS_WIDTH
  72 #define CONFIG_NANDSIM_BUS_WIDTH  8
  73 #endif
  74 #ifndef CONFIG_NANDSIM_DO_DELAYS
  75 #define CONFIG_NANDSIM_DO_DELAYS  0
  76 #endif
  77 #ifndef CONFIG_NANDSIM_LOG
  78 #define CONFIG_NANDSIM_LOG        0
  79 #endif
  80 #ifndef CONFIG_NANDSIM_DBG
  81 #define CONFIG_NANDSIM_DBG        0
  82 #endif
  83
  84 static uint first_id_byte  = CONFIG_NANDSIM_FIRST_ID_BYTE;
  85 static uint second_id_byte = CONFIG_NANDSIM_SECOND_ID_BYTE;
  86 static uint third_id_byte  = CONFIG_NANDSIM_THIRD_ID_BYTE;
  87 static uint fourth_id_byte = CONFIG_NANDSIM_FOURTH_ID_BYTE;
  88 static uint access_delay   = CONFIG_NANDSIM_ACCESS_DELAY;
  89 static uint programm_delay = CONFIG_NANDSIM_PROGRAMM_DELAY;
  90 static uint erase_delay    = CONFIG_NANDSIM_ERASE_DELAY;
  91 static uint output_cycle   = CONFIG_NANDSIM_OUTPUT_CYCLE;
  92 static uint input_cycle    = CONFIG_NANDSIM_INPUT_CYCLE;
  93 static uint bus_width      = CONFIG_NANDSIM_BUS_WIDTH;
  94 static uint do_delays      = CONFIG_NANDSIM_DO_DELAYS;
  95 static uint log            = CONFIG_NANDSIM_LOG;
  96 static uint dbg            = CONFIG_NANDSIM_DBG;
  97
  98 module_param(first_id_byte,  uint, 0400);
  99 module_param(second_id_byte, uint, 0400);
 100 module_param(third_id_byte,  uint, 0400);
 101 module_param(fourth_id_byte, uint, 0400);
 102 module_param(access_delay,   uint, 0400);
 103 module_param(programm_delay, uint, 0400);
 104 module_param(erase_delay,    uint, 0400);
 105 module_param(output_cycle,   uint, 0400);
 106 module_param(input_cycle,    uint, 0400);
 107 module_param(bus_width,      uint, 0400);
 108 module_param(do_delays,      uint, 0400);
 109 module_param(log,            uint, 0400);
 110 module_param(dbg,            uint, 0400);
 111
 112 MODULE_PARM_DESC(first_id_byte,  "The fist byte returned by NAND Flash 'read ID' command (manufaturer ID)");
 113 MODULE_PARM_DESC(second_id_byte, "The second byte returned by NAND Flash 'read ID' command (chip ID)");
 114 MODULE_PARM_DESC(third_id_byte,  "The third byte returned by NAND Flash 'read ID' command");
 115 MODULE_PARM_DESC(fourth_id_byte, "The fourth byte returned by NAND Flash 'read ID' command");
 116 MODULE_PARM_DESC(access_delay,   "Initial page access delay (microiseconds)");
 117 MODULE_PARM_DESC(programm_delay, "Page programm delay (microseconds");
 118 MODULE_PARM_DESC(erase_delay,    "Sector erase delay (milliseconds)");
 119 MODULE_PARM_DESC(output_cycle,   "Word output (from flash) time (nanodeconds)");
 120 MODULE_PARM_DESC(input_cycle,    "Word input (to flash) time (nanodeconds)");
 121 MODULE_PARM_DESC(bus_width,      "Chip's bus width (8- or 16-bit)");
 122 MODULE_PARM_DESC(do_delays,      "Simulate NAND delays using busy-waits if not zero");
 123 MODULE_PARM_DESC(log,            "Perform logging if not zero");
 124 MODULE_PARM_DESC(dbg,            "Output debug information if not zero");
 125
 126 /* The largest possible page size */
 127 #define NS_LARGEST_PAGE_SIZE    2048
 128
 129 /* The prefix for simulator output */
 130 #define NS_OUTPUT_PREFIX "[nandsim]"
 131
 132 /* Simulator's output macros (logging, debugging, warning, error) */
 133 #define NS_LOG(args...) \
 134         do { if (log) printk(KERN_DEBUG NS_OUTPUT_PREFIX " log: " args); } while(0)
 135 #define NS_DBG(args...) \
 136         do { if (dbg) printk(KERN_DEBUG NS_OUTPUT_PREFIX " debug: " args); } while(0)
 137 #define NS_WARN(args...) \
 138         do { printk(KERN_WARNING NS_OUTPUT_PREFIX " warnig: " args); } while(0)
 139 #define NS_ERR(args...) \
 140         do { printk(KERN_ERR NS_OUTPUT_PREFIX " errorr: " args); } while(0)
 141
 142 /* Busy-wait delay macros (microseconds, milliseconds) */
 143 #define NS_UDELAY(us) \
 144         do { if (do_delays) udelay(us); } while(0)
 145 #define NS_MDELAY(us) \
 146         do { if (do_delays) mdelay(us); } while(0)
 147
 148 /* Is the nandsim structure initialized ? */
 149 #define NS_IS_INITIALIZED(ns) ((ns)->geom.totsz != 0)
 150
 151 /* Good operation completion status */
 152 #define NS_STATUS_OK(ns) (NAND_STATUS_READY | (NAND_STATUS_WP * ((ns)->lines.wp == 0)))
 153
 154 /* Operation failed completion status */
 155 #define NS_STATUS_FAILED(ns) (NAND_STATUS_FAIL | NS_STATUS_OK(ns))
 156
 157 /* Calculate the page offset in flash RAM image by (row, column) address */
 158 #define NS_RAW_OFFSET(ns) \
 159         (((ns)->regs.row << (ns)->geom.pgshift) + ((ns)->regs.row * (ns)->geom.oobsz) + (ns)->regs.column)
 160
 161 /* Calculate the OOB offset in flash RAM image by (row, column) address */
 162 #define NS_RAW_OFFSET_OOB(ns) (NS_RAW_OFFSET(ns) + ns->geom.pgsz)
 163
 164 /* After a command is input, the simulator goes to one of the following states */
 165 #define STATE_CMD_READ0        0x00000001 /* read data from the beginning of page */
 166 #define STATE_CMD_READ1        0x00000002 /* read data from the second half of page */
 167 #define STATE_CMD_READSTART      0x00000003 /* read data second command (large page devices) */
 168 #define STATE_CMD_PAGEPROG     0x00000004 /* start page programm */
 169 #define STATE_CMD_READOOB      0x00000005 /* read OOB area */
 170 #define STATE_CMD_ERASE1       0x00000006 /* sector erase first command */
 171 #define STATE_CMD_STATUS       0x00000007 /* read status */
 172 #define STATE_CMD_STATUS_M     0x00000008 /* read multi-plane status (isn't implemented) */
 173 #define STATE_CMD_SEQIN        0x00000009 /* sequential data imput */
 174 #define STATE_CMD_READID       0x0000000A /* read ID */
 175 #define STATE_CMD_ERASE2       0x0000000B /* sector erase second command */
 176 #define STATE_CMD_RESET        0x0000000C /* reset */
 177 #define STATE_CMD_MASK         0x0000000F /* command states mask */
 178
 179 /* After an addres is input, the simulator goes to one of these states */
 180 #define STATE_ADDR_PAGE        0x00000010 /* full (row, column) address is accepted */
 181 #define STATE_ADDR_SEC         0x00000020 /* sector address was accepted */
 182 #define STATE_ADDR_ZERO        0x00000030 /* one byte zero address was accepted */
 183 #define STATE_ADDR_MASK        0x00000030 /* address states mask */
 184
 185 /* Durind data input/output the simulator is in these states */
 186 #define STATE_DATAIN           0x00000100 /* waiting for data input */
 187 #define STATE_DATAIN_MASK      0x00000100 /* data input states mask */
 188
 189 #define STATE_DATAOUT          0x00001000 /* waiting for page data output */
 190 #define STATE_DATAOUT_ID       0x00002000 /* waiting for ID bytes output */
 191 #define STATE_DATAOUT_STATUS   0x00003000 /* waiting for status output */
 192 #define STATE_DATAOUT_STATUS_M 0x00004000 /* waiting for multi-plane status output */
 193 #define STATE_DATAOUT_MASK     0x00007000 /* data output states mask */
 194
 195 /* Previous operation is done, ready to accept new requests */
 196 #define STATE_READY            0x00000000
 197
 198 /* This state is used to mark that the next state isn't known yet */
 199 #define STATE_UNKNOWN          0x10000000
 200
 201 /* Simulator's actions bit masks */
 202 #define ACTION_CPY       0x00100000 /* copy page/OOB to the internal buffer */
 203 #define ACTION_PRGPAGE   0x00200000 /* programm the internal buffer to flash */
 204 #define ACTION_SECERASE  0x00300000 /* erase sector */
 205 #define ACTION_ZEROOFF   0x00400000 /* don't add any offset to address */
 206 #define ACTION_HALFOFF   0x00500000 /* add to address half of page */
 207 #define ACTION_OOBOFF    0x00600000 /* add to address OOB offset */
 208 #define ACTION_MASK      0x00700000 /* action mask */
 209
 210 #define NS_OPER_NUM      12 /* Number of operations supported by the simulator */
 211 #define NS_OPER_STATES   6  /* Maximum number of states in operation */
 212
 213 #define OPT_ANY          0xFFFFFFFF /* any chip supports this operation */
 214 #define OPT_PAGE256      0x00000001 /* 256-byte  page chips */
 215 #define OPT_PAGE512      0x00000002 /* 512-byte  page chips */
 216 #define OPT_PAGE2048     0x00000008 /* 2048-byte page chips */
 217 #define OPT_SMARTMEDIA   0x00000010 /* SmartMedia technology chips */
 218 #define OPT_AUTOINCR     0x00000020 /* page number auto inctimentation is possible */
 219 #define OPT_PAGE512_8BIT 0x00000040 /* 512-byte page chips with 8-bit bus width */
 220 #define OPT_LARGEPAGE    (OPT_PAGE2048) /* 2048-byte page chips */
 221 #define OPT_SMALLPAGE    (OPT_PAGE256  | OPT_PAGE512)  /* 256 and 512-byte page chips */
 222
 223 /* Remove action bits ftom state */
 224 #define NS_STATE(x) ((x) & ~ACTION_MASK)
 225
 226 /*
 227  * Maximum previous states which need to be saved. Currently saving is
 228  * only needed for page programm operation with preceeded read command
 229  * (which is only valid for 512-byte pages).
 230  */
 231 #define NS_MAX_PREVSTATES 1
 232
 233 /*
 234  * The structure which describes all the internal simulator data.
 235  */
 236 struct nandsim {
 237         struct mtd_partition part;
 238
 239         uint busw;              /* flash chip bus width (8 or 16) */
 240         u_char ids[4];          /* chip's ID bytes */
 241         uint32_t options;       /* chip's characteristic bits */
 242         uint32_t state;         /* current chip state */
 243         uint32_t nxstate;       /* next expected state */
 244
 245         uint32_t *op;           /* current operation, NULL operations isn't known yet  */
 246         uint32_t pstates[NS_MAX_PREVSTATES]; /* previous states */
 247         uint16_t npstates;      /* number of previous states saved */
 248         uint16_t stateidx;      /* current state index */
 249
 250         /* The simulated NAND flash image */
 251         union flash_media {
 252                 u_char *byte;
 253                 uint16_t    *word;
 254         } mem;
 255
 256         /* Internal buffer of page + OOB size bytes */
 257         union internal_buffer {
 258                 u_char *byte;    /* for byte access */
 259                 uint16_t *word;  /* for 16-bit word access */
 260         } buf;
 261
 262         /* NAND flash "geometry" */
 263         struct nandsin_geometry {
 264                 uint32_t totsz;     /* total flash size, bytes */
 265                 uint32_t secsz;     /* flash sector (erase block) size, bytes */
 266                 uint pgsz;          /* NAND flash page size, bytes */
 267                 uint oobsz;         /* page OOB area size, bytes */
 268                 uint32_t totszoob;  /* total flash size including OOB, bytes */
 269                 uint pgszoob;       /* page size including OOB , bytes*/
 270                 uint secszoob;      /* sector size including OOB, bytes */
 271                 uint pgnum;         /* total number of pages */
 272                 uint pgsec;         /* number of pages per sector */
 273                 uint secshift;      /* bits number in sector size */
 274                 uint pgshift;       /* bits number in page size */
 275                 uint oobshift;      /* bits number in OOB size */
 276                 uint pgaddrbytes;   /* bytes per page address */
 277                 uint secaddrbytes;  /* bytes per sector address */
 278                 uint idbytes;       /* the number ID bytes that this chip outputs */
 279         } geom;
 280
 281         /* NAND flash internal registers */
 282         struct nandsim_regs {
 283                 unsigned command; /* the command register */
 284                 u_char   status;  /* the status register */
 285                 uint     row;     /* the page number */
 286                 uint     column;  /* the offset within page */
 287                 uint     count;   /* internal counter */
 288                 uint     num;     /* number of bytes which must be processed */
 289                 uint     off;     /* fixed page offset */
 290         } regs;
 291
 292         /* NAND flash lines state */
 293         struct ns_lines_status {
 294                 int ce;  /* chip Enable */
 295                 int cle; /* command Latch Enable */
 296                 int ale; /* address Latch Enable */
 297                 int wp;  /* write Protect */
 298         } lines;
 299 };
 300
 301 /*
 302  * Operations array. To perform any operation the simulator must pass
 303  * through the correspondent states chain.
 304  */
 305 static struct nandsim_operations {
 306         uint32_t reqopts;  /* options which are required to perform the operation */
 307         uint32_t states[NS_OPER_STATES]; /* operation's states */
 308 } ops[NS_OPER_NUM] = {
 309         /* Read page + OOB from the beginning */
 310         {OPT_SMALLPAGE, {STATE_CMD_READ0 | ACTION_ZEROOFF, STATE_ADDR_PAGE | ACTION_CPY,
 311                         STATE_DATAOUT, STATE_READY}},
 312         /* Read page + OOB from the second half */
 313         {OPT_PAGE512_8BIT, {STATE_CMD_READ1 | ACTION_HALFOFF, STATE_ADDR_PAGE | ACTION_CPY,
 314                         STATE_DATAOUT, STATE_READY}},
 315         /* Read OOB */
 316         {OPT_SMALLPAGE, {STATE_CMD_READOOB | ACTION_OOBOFF, STATE_ADDR_PAGE | ACTION_CPY,
 317                         STATE_DATAOUT, STATE_READY}},
 318         /* Programm page starting from the beginning */
 319         {OPT_ANY, {STATE_CMD_SEQIN, STATE_ADDR_PAGE, STATE_DATAIN,
 320                         STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 321         /* Programm page starting from the beginning */
 322         {OPT_SMALLPAGE, {STATE_CMD_READ0, STATE_CMD_SEQIN | ACTION_ZEROOFF, STATE_ADDR_PAGE,
 323                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 324         /* Programm page starting from the second half */
 325         {OPT_PAGE512, {STATE_CMD_READ1, STATE_CMD_SEQIN | ACTION_HALFOFF, STATE_ADDR_PAGE,
 326                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 327         /* Programm OOB */
 328         {OPT_SMALLPAGE, {STATE_CMD_READOOB, STATE_CMD_SEQIN | ACTION_OOBOFF, STATE_ADDR_PAGE,
 329                               STATE_DATAIN, STATE_CMD_PAGEPROG | ACTION_PRGPAGE, STATE_READY}},
 330         /* Erase sector */
 331         {OPT_ANY, {STATE_CMD_ERASE1, STATE_ADDR_SEC, STATE_CMD_ERASE2 | ACTION_SECERASE, STATE_READY}},
 332         /* Read status */
 333         {OPT_ANY, {STATE_CMD_STATUS, STATE_DATAOUT_STATUS, STATE_READY}},
 334         /* Read multi-plane status */
 335         {OPT_SMARTMEDIA, {STATE_CMD_STATUS_M, STATE_DATAOUT_STATUS_M, STATE_READY}},
 336         /* Read ID */
 337         {OPT_ANY, {STATE_CMD_READID, STATE_ADDR_ZERO, STATE_DATAOUT_ID, STATE_READY}},
 338         /* Large page devices read page */
 339         {OPT_LARGEPAGE, {STATE_CMD_READ0, STATE_ADDR_PAGE, STATE_CMD_READSTART | ACTION_CPY,
 340                                STATE_DATAOUT, STATE_READY}}
 341 };
 342
 343 /* MTD structure for NAND controller */
 344 static struct mtd_info *nsmtd;
 345
 346 static u_char ns_verify_buf[NS_LARGEST_PAGE_SIZE];
 347
 348 /*
 349  * Initialize the nandsim structure.
 350  *
 351  * RETURNS: 0 if success, -ERRNO if failure.
 352  */
 353 static int
 354 init_nandsim(struct mtd_info *mtd)
 355 {
 356         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
 357         struct nandsim   *ns   = (struct nandsim *)(chip->priv);
 358         int i;
 359
 360         if (NS_IS_INITIALIZED(ns)) {
 361                 NS_ERR("init_nandsim: nandsim is already initialized\n");
 362                 return -EIO;
 363         }
 364
 365         /* Force mtd to not do delays */
 366         chip->chip_delay = 0;
 367
 368         /* Initialize the NAND flash parameters */
 369         ns->busw = chip->options & NAND_BUSWIDTH_16 ? 16 : 8;
 370         ns->geom.totsz    = mtd->size;
 371         ns->geom.pgsz     = mtd->writesize;
 372         ns->geom.oobsz    = mtd->oobsize;
 373         ns->geom.secsz    = mtd->erasesize;
 374         ns->geom.pgszoob  = ns->geom.pgsz + ns->geom.oobsz;
 375         ns->geom.pgnum    = ns->geom.totsz / ns->geom.pgsz;
 376         ns->geom.totszoob = ns->geom.totsz + ns->geom.pgnum * ns->geom.oobsz;
 377         ns->geom.secshift = ffs(ns->geom.secsz) - 1;
 378         ns->geom.pgshift  = chip->page_shift;
 379         ns->geom.oobshift = ffs(ns->geom.oobsz) - 1;
 380         ns->geom.pgsec    = ns->geom.secsz / ns->geom.pgsz;
 381         ns->geom.secszoob = ns->geom.secsz + ns->geom.oobsz * ns->geom.pgsec;
 382         ns->options = 0;
 383
 384         if (ns->geom.pgsz == 256) {
 385                 ns->options |= OPT_PAGE256;
 386         }
 387         else if (ns->geom.pgsz == 512) {
 388                 ns->options |= (OPT_PAGE512 | OPT_AUTOINCR);
 389                 if (ns->busw == 8)
 390                         ns->options |= OPT_PAGE512_8BIT;
 391         } else if (ns->geom.pgsz == 2048) {
 392                 ns->options |= OPT_PAGE2048;
 393         } else {
 394                 NS_ERR("init_nandsim: unknown page size %u\n", ns->geom.pgsz);
 395                 return -EIO;
 396         }
 397
 398         if (ns->options & OPT_SMALLPAGE) {
 399                 if (ns->geom.totsz < (64 << 20)) {
 400                         ns->geom.pgaddrbytes  = 3;
 401                         ns->geom.secaddrbytes = 2;
 402                 } else {
 403                         ns->geom.pgaddrbytes  = 4;
 404                         ns->geom.secaddrbytes = 3;
 405                 }
 406         } else {
 407                 if (ns->geom.totsz <= (128 << 20)) {
 408                         ns->geom.pgaddrbytes  = 5;
 409                         ns->geom.secaddrbytes = 2;
 410                 } else {
 411                         ns->geom.pgaddrbytes  = 5;
 412                         ns->geom.secaddrbytes = 3;
 413                 }
 414         }
 415
 416         /* Detect how many ID bytes the NAND chip outputs */
 417         for (i = 0; nand_flash_ids[i].name != NULL; i++) {
 418                 if (second_id_byte != nand_flash_ids[i].id)
 419                         continue;
 420                 if (!(nand_flash_ids[i].options & NAND_NO_AUTOINCR))
 421                         ns->options |= OPT_AUTOINCR;
 422         }
 423
 424         if (ns->busw == 16)
 425                 NS_WARN("16-bit flashes support wasn't tested\n");
 426
 427         printk("flash size: %u MiB\n",          ns->geom.totsz >> 20);
 428         printk("page size: %u bytes\n",         ns->geom.pgsz);
 429         printk("OOB area size: %u bytes\n",     ns->geom.oobsz);
 430         printk("sector size: %u KiB\n",         ns->geom.secsz >> 10);
 431         printk("pages number: %u\n",            ns->geom.pgnum);
 432         printk("pages per sector: %u\n",        ns->geom.pgsec);
 433         printk("bus width: %u\n",               ns->busw);
 434         printk("bits in sector size: %u\n",     ns->geom.secshift);
 435         printk("bits in page size: %u\n",       ns->geom.pgshift);
 436         printk("bits in OOB size: %u\n",        ns->geom.oobshift);
 437         printk("flash size with OOB: %u KiB\n", ns->geom.totszoob >> 10);
 438         printk("page address bytes: %u\n",      ns->geom.pgaddrbytes);
 439         printk("sector address bytes: %u\n",    ns->geom.secaddrbytes);
 440         printk("options: %#x\n",                ns->options);
 441
 442         /* Map / allocate and initialize the flash image */
 443 #ifdef CONFIG_NS_ABS_POS
 444         ns->mem.byte = ioremap(CONFIG_NS_ABS_POS, ns->geom.totszoob);
 445         if (!ns->mem.byte) {
 446                 NS_ERR("init_nandsim: failed to map the NAND flash image at address %p\n",
 447                         (void *)CONFIG_NS_ABS_POS);
 448                 return -ENOMEM;
 449         }
 450 #else
 451         ns->mem.byte = vmalloc(ns->geom.totszoob);
 452         if (!ns->mem.byte) {
 453                 NS_ERR("init_nandsim: unable to allocate %u bytes for flash image\n",
 454                         ns->geom.totszoob);
 455                 return -ENOMEM;
 456         }
 457         memset(ns->mem.byte, 0xFF, ns->geom.totszoob);
 458 #endif
 459
 460         /* Allocate / initialize the internal buffer */
 461         ns->buf.byte = kmalloc(ns->geom.pgszoob, GFP_KERNEL);
 462         if (!ns->buf.byte) {
 463                 NS_ERR("init_nandsim: unable to allocate %u bytes for the internal buffer\n",
 464                         ns->geom.pgszoob);
 465                 goto error;
 466         }
 467         memset(ns->buf.byte, 0xFF, ns->geom.pgszoob);
 468
 469         /* Fill the partition_info structure */
 470         ns->part.name   = "NAND simulator partition";
 471         ns->part.offset = 0;
 472         ns->part.size   = ns->geom.totsz;
 473
 474         return 0;
 475
 476 error:
 477 #ifdef CONFIG_NS_ABS_POS
 478         iounmap(ns->mem.byte);
 479 #else
 480         vfree(ns->mem.byte);
 481 #endif
 482
 483         return -ENOMEM;
 484 }
 485
 486 /*
 487  * Free the nandsim structure.
 488  */
 489 static void
 490 free_nandsim(struct nandsim *ns)
 491 {
 492         kfree(ns->buf.byte);
 493
 494 #ifdef CONFIG_NS_ABS_POS
 495         iounmap(ns->mem.byte);
 496 #else
 497         vfree(ns->mem.byte);
 498 #endif
 499
 500         return;
 501 }
 502
 503 /*
 504  * Returns the string representation of 'state' state.
 505  */
 506 static char *
 507 get_state_name(uint32_t state)
 508 {
 509         switch (NS_STATE(state)) {
 510                 case STATE_CMD_READ0:
 511                         return "STATE_CMD_READ0";
 512                 case STATE_CMD_READ1:
 513                         return "STATE_CMD_READ1";
 514                 case STATE_CMD_PAGEPROG:
 515                         return "STATE_CMD_PAGEPROG";
 516                 case STATE_CMD_READOOB:
 517                         return "STATE_CMD_READOOB";
 518                 case STATE_CMD_READSTART:
 519                         return "STATE_CMD_READSTART";
 520                 case STATE_CMD_ERASE1:
 521                         return "STATE_CMD_ERASE1";
 522                 case STATE_CMD_STATUS:
 523                         return "STATE_CMD_STATUS";
 524                 case STATE_CMD_STATUS_M:
 525                         return "STATE_CMD_STATUS_M";
 526                 case STATE_CMD_SEQIN:
 527                         return "STATE_CMD_SEQIN";
 528                 case STATE_CMD_READID:
 529                         return "STATE_CMD_READID";
 530                 case STATE_CMD_ERASE2:
 531                         return "STATE_CMD_ERASE2";
 532                 case STATE_CMD_RESET:
 533                         return "STATE_CMD_RESET";
 534                 case STATE_ADDR_PAGE:
 535                         return "STATE_ADDR_PAGE";
 536                 case STATE_ADDR_SEC:
 537                         return "STATE_ADDR_SEC";
 538                 case STATE_ADDR_ZERO:
 539                         return "STATE_ADDR_ZERO";
 540                 case STATE_DATAIN:
 541                         return "STATE_DATAIN";
 542                 case STATE_DATAOUT:
 543                         return "STATE_DATAOUT";
 544                 case STATE_DATAOUT_ID:
 545                         return "STATE_DATAOUT_ID";
 546                 case STATE_DATAOUT_STATUS:
 547                         return "STATE_DATAOUT_STATUS";
 548                 case STATE_DATAOUT_STATUS_M:
 549                         return "STATE_DATAOUT_STATUS_M";
 550                 case STATE_READY:
 551                         return "STATE_READY";
 552                 case STATE_UNKNOWN:
 553                         return "STATE_UNKNOWN";
 554         }
 555
 556         NS_ERR("get_state_name: unknown state, BUG\n");
 557         return NULL;
 558 }
 559
 560 /*
 561  * Check if command is valid.
 562  *
 563  * RETURNS: 1 if wrong command, 0 if right.
 564  */
 565 static int
 566 check_command(int cmd)
 567 {
 568         switch (cmd) {
 569
 570         case NAND_CMD_READ0:
 571         case NAND_CMD_READSTART:
 572         case NAND_CMD_PAGEPROG:
 573         case NAND_CMD_READOOB:
 574         case NAND_CMD_ERASE1:
 575         case NAND_CMD_STATUS:
 576         case NAND_CMD_SEQIN:
 577         case NAND_CMD_READID:
 578         case NAND_CMD_ERASE2:
 579         case NAND_CMD_RESET:
 580         case NAND_CMD_READ1:
 581                 return 0;
 582
 583         case NAND_CMD_STATUS_MULTI:
 584         default:
 585                 return 1;
 586         }
 587 }
 588
 589 /*
 590  * Returns state after command is accepted by command number.
 591  */
 592 static uint32_t
 593 get_state_by_command(unsigned command)
 594 {
 595         switch (command) {
 596                 case NAND_CMD_READ0:
 597                         return STATE_CMD_READ0;
 598                 case NAND_CMD_READ1:
 599                         return STATE_CMD_READ1;
 600                 case NAND_CMD_PAGEPROG:
 601                         return STATE_CMD_PAGEPROG;
 602                 case NAND_CMD_READSTART:
 603                         return STATE_CMD_READSTART;
 604                 case NAND_CMD_READOOB:
 605                         return STATE_CMD_READOOB;
 606                 case NAND_CMD_ERASE1:
 607                         return STATE_CMD_ERASE1;
 608                 case NAND_CMD_STATUS:
 609                         return STATE_CMD_STATUS;
 610                 case NAND_CMD_STATUS_MULTI:
 611                         return STATE_CMD_STATUS_M;
 612                 case NAND_CMD_SEQIN:
 613                         return STATE_CMD_SEQIN;
 614                 case NAND_CMD_READID:
 615                         return STATE_CMD_READID;
 616                 case NAND_CMD_ERASE2:
 617                         return STATE_CMD_ERASE2;
 618                 case NAND_CMD_RESET:
 619                         return STATE_CMD_RESET;
 620         }
 621
 622         NS_ERR("get_state_by_command: unknown command, BUG\n");
 623         return 0;
 624 }
 625
 626 /*
 627  * Move an address byte to the correspondent internal register.
 628  */
 629 static inline void
 630 accept_addr_byte(struct nandsim *ns, u_char bt)
 631 {
 632         uint byte = (uint)bt;
 633
 634         if (ns->regs.count < (ns->geom.pgaddrbytes - ns->geom.secaddrbytes))
 635                 ns->regs.column |= (byte << 8 * ns->regs.count);
 636         else {
 637                 ns->regs.row |= (byte << 8 * (ns->regs.count -
 638                                                 ns->geom.pgaddrbytes +
 639                                                 ns->geom.secaddrbytes));
 640         }
 641
 642         return;
 643 }
 644
 645 /*
 646  * Switch to STATE_READY state.
 647  */
 648 static inline void
 649 switch_to_ready_state(struct nandsim *ns, u_char status)
 650 {
 651         NS_DBG("switch_to_ready_state: switch to %s state\n", get_state_name(STATE_READY));
 652
 653         ns->state       = STATE_READY;
 654         ns->nxstate     = STATE_UNKNOWN;
 655         ns->op          = NULL;
 656         ns->npstates    = 0;
 657         ns->stateidx    = 0;
 658         ns->regs.num    = 0;
 659         ns->regs.count  = 0;
 660         ns->regs.off    = 0;
 661         ns->regs.row    = 0;
 662         ns->regs.column = 0;
 663         ns->regs.status = status;
 664 }
 665
 666 /*
 667  * If the operation isn't known yet, try to find it in the global array
 668  * of supported operations.
 669  *
 670  * Operation can be unknown because of the following.
 671  *   1. New command was accepted and this is the firs call to find the
 672  *      correspondent states chain. In this case ns->npstates = 0;
 673  *   2. There is several operations which begin with the same command(s)
 674  *      (for example program from the second half and read from the
 675  *      second half operations both begin with the READ1 command). In this
 676  *      case the ns->pstates[] array contains previous states.
 677  *
 678  * Thus, the function tries to find operation containing the following
 679  * states (if the 'flag' parameter is 0):
 680  *    ns->pstates[0], ... ns->pstates[ns->npstates], ns->state
 681  *
 682  * If (one and only one) matching operation is found, it is accepted (
 683  * ns->ops, ns->state, ns->nxstate are initialized, ns->npstate is
 684  * zeroed).
 685  *
 686  * If there are several maches, the current state is pushed to the
 687  * ns->pstates.
 688  *
 689  * The operation can be unknown only while commands are input to the chip.
 690  * As soon as address command is accepted, the operation must be known.
 691  * In such situation the function is called with 'flag' != 0, and the
 692  * operation is searched using the following pattern:
 693  *     ns->pstates[0], ... ns->pstates[ns->npstates], <address input>
 694  *
 695  * It is supposed that this pattern must either match one operation on
 696  * none. There can't be ambiguity in that case.
 697  *
 698  * If no matches found, the functions does the following:
 699  *   1. if there are saved states present, try to ignore them and search
 700  *      again only using the last command. If nothing was found, switch
 701  *      to the STATE_READY state.
 702  *   2. if there are no saved states, switch to the STATE_READY state.
 703  *
 704  * RETURNS: -2 - no matched operations found.
 705  *          -1 - several matches.
 706  *           0 - operation is found.
 707  */
 708 static int
 709 find_operation(struct nandsim *ns, uint32_t flag)
 710 {
 711         int opsfound = 0;
 712         int i, j, idx = 0;
 713
 714         for (i = 0; i < NS_OPER_NUM; i++) {
 715
 716                 int found = 1;
 717
 718                 if (!(ns->options & ops[i].reqopts))
 719                         /* Ignore operations we can't perform */
 720                         continue;
 721
 722                 if (flag) {
 723                         if (!(ops[i].states[ns->npstates] & STATE_ADDR_MASK))
 724                                 continue;
 725                 } else {
 726                         if (NS_STATE(ns->state) != NS_STATE(ops[i].states[ns->npstates]))
 727                                 continue;
 728                 }
 729
 730                 for (j = 0; j < ns->npstates; j++)
 731                         if (NS_STATE(ops[i].states[j]) != NS_STATE(ns->pstates[j])
 732                                 && (ns->options & ops[idx].reqopts)) {
 733                                 found = 0;
 734                                 break;
 735                         }
 736
 737                 if (found) {
 738                         idx = i;
 739                         opsfound += 1;
 740                 }
 741         }
 742
 743         if (opsfound == 1) {
 744                 /* Exact match */
 745                 ns->op = &ops[idx].states[0];
 746                 if (flag) {
 747                         /*
 748                          * In this case the find_operation function was
 749                          * called when address has just began input. But it isn't
 750                          * yet fully input and the current state must
 751                          * not be one of STATE_ADDR_*, but the STATE_ADDR_*
 752                          * state must be the next state (ns->nxstate).
 753                          */
 754                         ns->stateidx = ns->npstates - 1;
 755                 } else {
 756                         ns->stateidx = ns->npstates;
 757                 }
 758                 ns->npstates = 0;
 759                 ns->state = ns->op[ns->stateidx];
 760                 ns->nxstate = ns->op[ns->stateidx + 1];
 761                 NS_DBG("find_operation: operation found, index: %d, state: %s, nxstate %s\n",
 762                                 idx, get_state_name(ns->state), get_state_name(ns->nxstate));
 763                 return 0;
 764         }
 765
 766         if (opsfound == 0) {
 767                 /* Nothing was found. Try to ignore previous commands (if any) and search again */
 768                 if (ns->npstates != 0) {
 769                         NS_DBG("find_operation: no operation found, try again with state %s\n",
 770                                         get_state_name(ns->state));
 771                         ns->npstates = 0;
 772                         return find_operation(ns, 0);
 773
 774                 }
 775                 NS_DBG("find_operation: no operations found\n");
 776                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
 777                 return -2;
 778         }
 779
 780         if (flag) {
 781                 /* This shouldn't happen */
 782                 NS_DBG("find_operation: BUG, operation must be known if address is input\n");
 783                 return -2;
 784         }
 785
 786         NS_DBG("find_operation: there is still ambiguity\n");
 787
 788         ns->pstates[ns->npstates++] = ns->state;
 789
 790         return -1;
 791 }
 792
 793 /*
 794  * If state has any action bit, perform this action.
 795  *
 796  * RETURNS: 0 if success, -1 if error.
 797  */
 798 static int
 799 do_state_action(struct nandsim *ns, uint32_t action)
 800 {
 801         int i, num;
 802         int busdiv = ns->busw == 8 ? 1 : 2;
 803
 804         action &= ACTION_MASK;
 805
 806         /* Check that page address input is correct */
 807         if (action != ACTION_SECERASE && ns->regs.row >= ns->geom.pgnum) {
 808                 NS_WARN("do_state_action: wrong page number (%#x)\n", ns->regs.row);
 809                 return -1;
 810         }
 811
 812         switch (action) {
 813
 814         case ACTION_CPY:
 815                 /*
 816                  * Copy page data to the internal buffer.
 817                  */
 818
 819                 /* Column shouldn't be very large */
 820                 if (ns->regs.column >= (ns->geom.pgszoob - ns->regs.off)) {
 821                         NS_ERR("do_state_action: column number is too large\n");
 822                         break;
 823                 }
 824                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
 825                 memcpy(ns->buf.byte, ns->mem.byte + NS_RAW_OFFSET(ns) + ns->regs.off, num);
 826
 827                 NS_DBG("do_state_action: (ACTION_CPY:) copy %d bytes to int buf, raw offset %d\n",
 828                         num, NS_RAW_OFFSET(ns) + ns->regs.off);
 829
 830                 if (ns->regs.off == 0)
 831                         NS_LOG("read page %d\n", ns->regs.row);
 832                 else if (ns->regs.off < ns->geom.pgsz)
 833                         NS_LOG("read page %d (second half)\n", ns->regs.row);
 834                 else
 835                         NS_LOG("read OOB of page %d\n", ns->regs.row);
 836
 837                 NS_UDELAY(access_delay);
 838                 NS_UDELAY(input_cycle * ns->geom.pgsz / 1000 / busdiv);
 839
 840                 break;
 841
 842         case ACTION_SECERASE:
 843                 /*
 844                  * Erase sector.
 845                  */
 846
 847                 if (ns->lines.wp) {
 848                         NS_ERR("do_state_action: device is write-protected, ignore sector erase\n");
 849                         return -1;
 850                 }
 851
 852                 if (ns->regs.row >= ns->geom.pgnum - ns->geom.pgsec
 853                         || (ns->regs.row & ~(ns->geom.secsz - 1))) {
 854                         NS_ERR("do_state_action: wrong sector address (%#x)\n", ns->regs.row);
 855                         return -1;
 856                 }
 857
 858                 ns->regs.row = (ns->regs.row <<
 859                                 8 * (ns->geom.pgaddrbytes - ns->geom.secaddrbytes)) | ns->regs.column;
 860                 ns->regs.column = 0;
 861
 862                 NS_DBG("do_state_action: erase sector at address %#x, off = %d\n",
 863                                 ns->regs.row, NS_RAW_OFFSET(ns));
 864                 NS_LOG("erase sector %d\n", ns->regs.row >> (ns->geom.secshift - ns->geom.pgshift));
 865
 866                 memset(ns->mem.byte + NS_RAW_OFFSET(ns), 0xFF, ns->geom.secszoob);
 867
 868                 NS_MDELAY(erase_delay);
 869
 870                 break;
 871
 872         case ACTION_PRGPAGE:
 873                 /*
 874                  * Programm page - move internal buffer data to the page.
 875                  */
 876
 877                 if (ns->lines.wp) {
 878                         NS_WARN("do_state_action: device is write-protected, programm\n");
 879                         return -1;
 880                 }
 881
 882                 num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
 883                 if (num != ns->regs.count) {
 884                         NS_ERR("do_state_action: too few bytes were input (%d instead of %d)\n",
 885                                         ns->regs.count, num);
 886                         return -1;
 887                 }
 888
 889                 for (i = 0; i < num; i++)
 890                         ns->mem.byte[NS_RAW_OFFSET(ns) + ns->regs.off + i] &= ns->buf.byte[i];
 891
 892                 NS_DBG("do_state_action: copy %d bytes from int buf to (%#x, %#x), raw off = %d\n",
 893                         num, ns->regs.row, ns->regs.column, NS_RAW_OFFSET(ns) + ns->regs.off);
 894                 NS_LOG("programm page %d\n", ns->regs.row);
 895
 896                 NS_UDELAY(programm_delay);
 897                 NS_UDELAY(output_cycle * ns->geom.pgsz / 1000 / busdiv);
 898
 899                 break;
 900
 901         case ACTION_ZEROOFF:
 902                 NS_DBG("do_state_action: set internal offset to 0\n");
 903                 ns->regs.off = 0;
 904                 break;
 905
 906         case ACTION_HALFOFF:
 907                 if (!(ns->options & OPT_PAGE512_8BIT)) {
 908                         NS_ERR("do_state_action: BUG! can't skip half of page for non-512"
 909                                 "byte page size 8x chips\n");
 910                         return -1;
 911                 }
 912                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz/2);
 913                 ns->regs.off = ns->geom.pgsz/2;
 914                 break;
 915
 916         case ACTION_OOBOFF:
 917                 NS_DBG("do_state_action: set internal offset to %d\n", ns->geom.pgsz);
 918                 ns->regs.off = ns->geom.pgsz;
 919                 break;
 920
 921         default:
 922                 NS_DBG("do_state_action: BUG! unknown action\n");
 923         }
 924
 925         return 0;
 926 }
 927
 928 /*
 929  * Switch simulator's state.
 930  */
 931 static void
 932 switch_state(struct nandsim *ns)
 933 {
 934         if (ns->op) {
 935                 /*
 936                  * The current operation have already been identified.
 937                  * Just follow the states chain.
 938                  */
 939
 940                 ns->stateidx += 1;
 941                 ns->state = ns->nxstate;
 942                 ns->nxstate = ns->op[ns->stateidx + 1];
 943
 944                 NS_DBG("switch_state: operation is known, switch to the next state, "
 945                         "state: %s, nxstate: %s\n",
 946                         get_state_name(ns->state), get_state_name(ns->nxstate));
 947
 948                 /* See, whether we need to do some action */
 949                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
 950                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
 951                         return;
 952                 }
 953
 954         } else {
 955                 /*
 956                  * We don't yet know which operation we perform.
 957                  * Try to identify it.
 958                  */
 959
 960                 /*
 961                  *  The only event causing the switch_state function to
 962                  *  be called with yet unknown operation is new command.
 963                  */
 964                 ns->state = get_state_by_command(ns->regs.command);
 965
 966                 NS_DBG("switch_state: operation is unknown, try to find it\n");
 967
 968                 if (find_operation(ns, 0) != 0)
 969                         return;
 970
 971                 if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
 972                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
 973                         return;
 974                 }
 975         }
 976
 977         /* For 16x devices column means the page offset in words */
 978         if ((ns->nxstate & STATE_ADDR_MASK) && ns->busw == 16) {
 979                 NS_DBG("switch_state: double the column number for 16x device\n");
 980                 ns->regs.column <<= 1;
 981         }
 982
 983         if (NS_STATE(ns->nxstate) == STATE_READY) {
 984                 /*
 985                  * The current state is the last. Return to STATE_READY
 986                  */
 987
 988                 u_char status = NS_STATUS_OK(ns);
 989
 990                 /* In case of data states, see if all bytes were input/output */
 991                 if ((ns->state & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK))
 992                         && ns->regs.count != ns->regs.num) {
 993                         NS_WARN("switch_state: not all bytes were processed, %d left\n",
 994                                         ns->regs.num - ns->regs.count);
 995                         status = NS_STATUS_FAILED(ns);
 996                 }
 997
 998                 NS_DBG("switch_state: operation complete, switch to STATE_READY state\n");
 999
1000                 switch_to_ready_state(ns, status);
1001
1002                 return;
1003         } else if (ns->nxstate & (STATE_DATAIN_MASK | STATE_DATAOUT_MASK)) {
1004                 /*
1005                  * If the next state is data input/output, switch to it now
1006                  */
1007
1008                 ns->state      = ns->nxstate;
1009                 ns->nxstate    = ns->op[++ns->stateidx + 1];
1010                 ns->regs.num   = ns->regs.count = 0;
1011
1012                 NS_DBG("switch_state: the next state is data I/O, switch, "
1013                         "state: %s, nxstate: %s\n",
1014                         get_state_name(ns->state), get_state_name(ns->nxstate));
1015
1016                 /*
1017                  * Set the internal register to the count of bytes which
1018                  * are expected to be input or output
1019                  */
1020                 switch (NS_STATE(ns->state)) {
1021                         case STATE_DATAIN:
1022                         case STATE_DATAOUT:
1023                                 ns->regs.num = ns->geom.pgszoob - ns->regs.off - ns->regs.column;
1024                                 break;
1025
1026                         case STATE_DATAOUT_ID:
1027                                 ns->regs.num = ns->geom.idbytes;
1028                                 break;
1029
1030                         case STATE_DATAOUT_STATUS:
1031                         case STATE_DATAOUT_STATUS_M:
1032                                 ns->regs.count = ns->regs.num = 0;
1033                                 break;
1034
1035                         default:
1036                                 NS_ERR("switch_state: BUG! unknown data state\n");
1037                 }
1038
1039         } else if (ns->nxstate & STATE_ADDR_MASK) {
1040                 /*
1041                  * If the next state is address input, set the internal
1042                  * register to the number of expected address bytes
1043                  */
1044
1045                 ns->regs.count = 0;
1046
1047                 switch (NS_STATE(ns->nxstate)) {
1048                         case STATE_ADDR_PAGE:
1049                                 ns->regs.num = ns->geom.pgaddrbytes;
1050
1051                                 break;
1052                         case STATE_ADDR_SEC:
1053                                 ns->regs.num = ns->geom.secaddrbytes;
1054                                 break;
1055
1056                         case STATE_ADDR_ZERO:
1057                                 ns->regs.num = 1;
1058                                 break;
1059
1060                         default:
1061                                 NS_ERR("switch_state: BUG! unknown address state\n");
1062                 }
1063         } else {
1064                 /*
1065                  * Just reset internal counters.
1066                  */
1067
1068                 ns->regs.num = 0;
1069                 ns->regs.count = 0;
1070         }
1071 }
1072
1073 static u_char
1074 ns_nand_read_byte(struct mtd_info *mtd)
1075 {
1076         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1077         u_char outb = 0x00;
1078
1079         /* Sanity and correctness checks */
1080         if (!ns->lines.ce) {
1081                 NS_ERR("read_byte: chip is disabled, return %#x\n", (uint)outb);
1082                 return outb;
1083         }
1084         if (ns->lines.ale || ns->lines.cle) {
1085                 NS_ERR("read_byte: ALE or CLE pin is high, return %#x\n", (uint)outb);
1086                 return outb;
1087         }
1088         if (!(ns->state & STATE_DATAOUT_MASK)) {
1089                 NS_WARN("read_byte: unexpected data output cycle, state is %s "
1090                         "return %#x\n", get_state_name(ns->state), (uint)outb);
1091                 return outb;
1092         }
1093
1094         /* Status register may be read as many times as it is wanted */
1095         if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS) {
1096                 NS_DBG("read_byte: return %#x status\n", ns->regs.status);
1097                 return ns->regs.status;
1098         }
1099
1100         /* Check if there is any data in the internal buffer which may be read */
1101         if (ns->regs.count == ns->regs.num) {
1102                 NS_WARN("read_byte: no more data to output, return %#x\n", (uint)outb);
1103                 return outb;
1104         }
1105
1106         switch (NS_STATE(ns->state)) {
1107                 case STATE_DATAOUT:
1108                         if (ns->busw == 8) {
1109                                 outb = ns->buf.byte[ns->regs.count];
1110                                 ns->regs.count += 1;
1111                         } else {
1112                                 outb = (u_char)cpu_to_le16(ns->buf.word[ns->regs.count >> 1]);
1113                                 ns->regs.count += 2;
1114                         }
1115                         break;
1116                 case STATE_DATAOUT_ID:
1117                         NS_DBG("read_byte: read ID byte %d, total = %d\n", ns->regs.count, ns->regs.num);
1118                         outb = ns->ids[ns->regs.count];
1119                         ns->regs.count += 1;
1120                         break;
1121                 default:
1122                         BUG();
1123         }
1124
1125         if (ns->regs.count == ns->regs.num) {
1126                 NS_DBG("read_byte: all bytes were read\n");
1127
1128                 /*
1129                  * The OPT_AUTOINCR allows to read next conseqitive pages without
1130                  * new read operation cycle.
1131                  */
1132                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
1133                         ns->regs.count = 0;
1134                         if (ns->regs.row + 1 < ns->geom.pgnum)
1135                                 ns->regs.row += 1;
1136                         NS_DBG("read_byte: switch to the next page (%#x)\n", ns->regs.row);
1137                         do_state_action(ns, ACTION_CPY);
1138                 }
1139                 else if (NS_STATE(ns->nxstate) == STATE_READY)
1140                         switch_state(ns);
1141
1142         }
1143
1144         return outb;
1145 }
1146
1147 static void
1148 ns_nand_write_byte(struct mtd_info *mtd, u_char byte)
1149 {
1150         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1151
1152         /* Sanity and correctness checks */
1153         if (!ns->lines.ce) {
1154                 NS_ERR("write_byte: chip is disabled, ignore write\n");
1155                 return;
1156         }
1157         if (ns->lines.ale && ns->lines.cle) {
1158                 NS_ERR("write_byte: ALE and CLE pins are high simultaneously, ignore write\n");
1159                 return;
1160         }
1161
1162         if (ns->lines.cle == 1) {
1163                 /*
1164                  * The byte written is a command.
1165                  */
1166
1167                 if (byte == NAND_CMD_RESET) {
1168                         NS_LOG("reset chip\n");
1169                         switch_to_ready_state(ns, NS_STATUS_OK(ns));
1170                         return;
1171                 }
1172
1173                 /*
1174                  * Chip might still be in STATE_DATAOUT
1175                  * (if OPT_AUTOINCR feature is supported), STATE_DATAOUT_STATUS or
1176                  * STATE_DATAOUT_STATUS_M state. If so, switch state.
1177                  */
1178                 if (NS_STATE(ns->state) == STATE_DATAOUT_STATUS
1179                         || NS_STATE(ns->state) == STATE_DATAOUT_STATUS_M
1180                         || ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT))
1181                         switch_state(ns);
1182
1183                 /* Check if chip is expecting command */
1184                 if (NS_STATE(ns->nxstate) != STATE_UNKNOWN && !(ns->nxstate & STATE_CMD_MASK)) {
1185                         /*
1186                          * We are in situation when something else (not command)
1187                          * was expected but command was input. In this case ignore
1188                          * previous command(s)/state(s) and accept the last one.
1189                          */
1190                         NS_WARN("write_byte: command (%#x) wasn't expected, expected state is %s, "
1191                                 "ignore previous states\n", (uint)byte, get_state_name(ns->nxstate));
1192                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1193                 }
1194
1195                 /* Check that the command byte is correct */
1196                 if (check_command(byte)) {
1197                         NS_ERR("write_byte: unknown command %#x\n", (uint)byte);
1198                         return;
1199                 }
1200
1201                 NS_DBG("command byte corresponding to %s state accepted\n",
1202                         get_state_name(get_state_by_command(byte)));
1203                 ns->regs.command = byte;
1204                 switch_state(ns);
1205
1206         } else if (ns->lines.ale == 1) {
1207                 /*
1208                  * The byte written is an address.
1209                  */
1210
1211                 if (NS_STATE(ns->nxstate) == STATE_UNKNOWN) {
1212
1213                         NS_DBG("write_byte: operation isn't known yet, identify it\n");
1214
1215                         if (find_operation(ns, 1) < 0)
1216                                 return;
1217
1218                         if ((ns->state & ACTION_MASK) && do_state_action(ns, ns->state) < 0) {
1219                                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1220                                 return;
1221                         }
1222
1223                         ns->regs.count = 0;
1224                         switch (NS_STATE(ns->nxstate)) {
1225                                 case STATE_ADDR_PAGE:
1226                                         ns->regs.num = ns->geom.pgaddrbytes;
1227                                         break;
1228                                 case STATE_ADDR_SEC:
1229                                         ns->regs.num = ns->geom.secaddrbytes;
1230                                         break;
1231                                 case STATE_ADDR_ZERO:
1232                                         ns->regs.num = 1;
1233                                         break;
1234                                 default:
1235                                         BUG();
1236                         }
1237                 }
1238
1239                 /* Check that chip is expecting address */
1240                 if (!(ns->nxstate & STATE_ADDR_MASK)) {
1241                         NS_ERR("write_byte: address (%#x) isn't expected, expected state is %s, "
1242                                 "switch to STATE_READY\n", (uint)byte, get_state_name(ns->nxstate));
1243                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1244                         return;
1245                 }
1246
1247                 /* Check if this is expected byte */
1248                 if (ns->regs.count == ns->regs.num) {
1249                         NS_ERR("write_byte: no more address bytes expected\n");
1250                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1251                         return;
1252                 }
1253
1254                 accept_addr_byte(ns, byte);
1255
1256                 ns->regs.count += 1;
1257
1258                 NS_DBG("write_byte: address byte %#x was accepted (%d bytes input, %d expected)\n",
1259                                 (uint)byte, ns->regs.count, ns->regs.num);
1260
1261                 if (ns->regs.count == ns->regs.num) {
1262                         NS_DBG("address (%#x, %#x) is accepted\n", ns->regs.row, ns->regs.column);
1263                         switch_state(ns);
1264                 }
1265
1266         } else {
1267                 /*
1268                  * The byte written is an input data.
1269                  */
1270
1271                 /* Check that chip is expecting data input */
1272                 if (!(ns->state & STATE_DATAIN_MASK)) {
1273                         NS_ERR("write_byte: data input (%#x) isn't expected, state is %s, "
1274                                 "switch to %s\n", (uint)byte,
1275                                 get_state_name(ns->state), get_state_name(STATE_READY));
1276                         switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1277                         return;
1278                 }
1279
1280                 /* Check if this is expected byte */
1281                 if (ns->regs.count == ns->regs.num) {
1282                         NS_WARN("write_byte: %u input bytes has already been accepted, ignore write\n",
1283                                         ns->regs.num);
1284                         return;
1285                 }
1286
1287                 if (ns->busw == 8) {
1288                         ns->buf.byte[ns->regs.count] = byte;
1289                         ns->regs.count += 1;
1290                 } else {
1291                         ns->buf.word[ns->regs.count >> 1] = cpu_to_le16((uint16_t)byte);
1292                         ns->regs.count += 2;
1293                 }
1294         }
1295
1296         return;
1297 }
1298
1299 static void ns_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int bitmask)
1300 {
1301         struct nandsim *ns = ((struct nand_chip *)mtd->priv)->priv;
1302
1303         ns->lines.cle = bitmask & NAND_CLE ? 1 : 0;
1304         ns->lines.ale = bitmask & NAND_ALE ? 1 : 0;
1305         ns->lines.ce = bitmask & NAND_NCE ? 1 : 0;
1306
1307         if (cmd != NAND_CMD_NONE)
1308                 ns_nand_write_byte(mtd, cmd);
1309 }
1310
1311 static int
1312 ns_device_ready(struct mtd_info *mtd)
1313 {
1314         NS_DBG("device_ready\n");
1315         return 1;
1316 }
1317
1318 static uint16_t
1319 ns_nand_read_word(struct mtd_info *mtd)
1320 {
1321         struct nand_chip *chip = (struct nand_chip *)mtd->priv;
1322
1323         NS_DBG("read_word\n");
1324
1325         return chip->read_byte(mtd) | (chip->read_byte(mtd) << 8);
1326 }
1327
1328 static void
1329 ns_nand_write_buf(struct mtd_info *mtd, const u_char *buf, int len)
1330 {
1331         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1332
1333         /* Check that chip is expecting data input */
1334         if (!(ns->state & STATE_DATAIN_MASK)) {
1335                 NS_ERR("write_buf: data input isn't expected, state is %s, "
1336                         "switch to STATE_READY\n", get_state_name(ns->state));
1337                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1338                 return;
1339         }
1340
1341         /* Check if these are expected bytes */
1342         if (ns->regs.count + len > ns->regs.num) {
1343                 NS_ERR("write_buf: too many input bytes\n");
1344                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1345                 return;
1346         }
1347
1348         memcpy(ns->buf.byte + ns->regs.count, buf, len);
1349         ns->regs.count += len;
1350
1351         if (ns->regs.count == ns->regs.num) {
1352                 NS_DBG("write_buf: %d bytes were written\n", ns->regs.count);
1353         }
1354 }
1355
1356 static void
1357 ns_nand_read_buf(struct mtd_info *mtd, u_char *buf, int len)
1358 {
1359         struct nandsim *ns = (struct nandsim *)((struct nand_chip *)mtd->priv)->priv;
1360
1361         /* Sanity and correctness checks */
1362         if (!ns->lines.ce) {
1363                 NS_ERR("read_buf: chip is disabled\n");
1364                 return;
1365         }
1366         if (ns->lines.ale || ns->lines.cle) {
1367                 NS_ERR("read_buf: ALE or CLE pin is high\n");
1368                 return;
1369         }
1370         if (!(ns->state & STATE_DATAOUT_MASK)) {
1371                 NS_WARN("read_buf: unexpected data output cycle, current state is %s\n",
1372                         get_state_name(ns->state));
1373                 return;
1374         }
1375
1376         if (NS_STATE(ns->state) != STATE_DATAOUT) {
1377                 int i;
1378
1379                 for (i = 0; i < len; i++)
1380                         buf[i] = ((struct nand_chip *)mtd->priv)->read_byte(mtd);
1381
1382                 return;
1383         }
1384
1385         /* Check if these are expected bytes */
1386         if (ns->regs.count + len > ns->regs.num) {
1387                 NS_ERR("read_buf: too many bytes to read\n");
1388                 switch_to_ready_state(ns, NS_STATUS_FAILED(ns));
1389                 return;
1390         }
1391
1392         memcpy(buf, ns->buf.byte + ns->regs.count, len);
1393         ns->regs.count += len;
1394
1395         if (ns->regs.count == ns->regs.num) {
1396                 if ((ns->options & OPT_AUTOINCR) && NS_STATE(ns->state) == STATE_DATAOUT) {
1397                         ns->regs.count = 0;
1398                         if (ns->regs.row + 1 < ns->geom.pgnum)
1399                                 ns->regs.row += 1;
1400                         NS_DBG("read_buf: switch to the next page (%#x)\n", ns->regs.row);
1401                         do_state_action(ns, ACTION_CPY);
1402                 }
1403                 else if (NS_STATE(ns->nxstate) == STATE_READY)
1404                         switch_state(ns);
1405         }
1406
1407         return;
1408 }
1409
1410 static int
1411 ns_nand_verify_buf(struct mtd_info *mtd, const u_char *buf, int len)
1412 {
1413         ns_nand_read_buf(mtd, (u_char *)&ns_verify_buf[0], len);
1414
1415         if (!memcmp(buf, &ns_verify_buf[0], len)) {
1416                 NS_DBG("verify_buf: the buffer is OK\n");
1417                 return 0;
1418         } else {
1419                 NS_DBG("verify_buf: the buffer is wrong\n");
1420                 return -EFAULT;
1421         }
1422 }
1423
1424 /*
1425  * Module initialization function
1426  */
1427 static int __init ns_init_module(void)
1428 {
1429         struct nand_chip *chip;
1430         struct nandsim *nand;
1431         int retval = -ENOMEM;
1432
1433         if (bus_width != 8 && bus_width != 16) {
1434                 NS_ERR("wrong bus width (%d), use only 8 or 16\n", bus_width);
1435                 return -EINVAL;
1436         }
1437
1438         /* Allocate and initialize mtd_info, nand_chip and nandsim structures */
1439         nsmtd = kmalloc(sizeof(struct mtd_info) + sizeof(struct nand_chip)
1440                                 + sizeof(struct nandsim), GFP_KERNEL);
1441         if (!nsmtd) {
1442                 NS_ERR("unable to allocate core structures.\n");
1443                 return -ENOMEM;
1444         }
1445         memset(nsmtd, 0, sizeof(struct mtd_info) + sizeof(struct nand_chip) +
1446                         sizeof(struct nandsim));
1447         chip        = (struct nand_chip *)(nsmtd + 1);
1448         nsmtd->priv = (void *)chip;
1449         nand        = (struct nandsim *)(chip + 1);
1450         chip->priv  = (void *)nand;
1451
1452         /*
1453          * Register simulator's callbacks.
1454          */
1455         chip->cmd_ctrl   = ns_hwcontrol;
1456         chip->read_byte  = ns_nand_read_byte;
1457         chip->dev_ready  = ns_device_ready;
1458         chip->write_buf  = ns_nand_write_buf;
1459         chip->read_buf   = ns_nand_read_buf;
1460         chip->verify_buf = ns_nand_verify_buf;
1461         chip->read_word  = ns_nand_read_word;
1462         chip->ecc.mode   = NAND_ECC_SOFT;
1463         chip->options   |= NAND_SKIP_BBTSCAN;
1464
1465         /*
1466          * Perform minimum nandsim structure initialization to handle
1467          * the initial ID read command correctly
1468          */
1469         if (third_id_byte != 0xFF || fourth_id_byte != 0xFF)
1470                 nand->geom.idbytes = 4;
1471         else
1472                 nand->geom.idbytes = 2;
1473         nand->regs.status = NS_STATUS_OK(nand);
1474         nand->nxstate = STATE_UNKNOWN;
1475         nand->options |= OPT_PAGE256; /* temporary value */
1476         nand->ids[0] = first_id_byte;
1477         nand->ids[1] = second_id_byte;
1478         nand->ids[2] = third_id_byte;
1479         nand->ids[3] = fourth_id_byte;
1480         if (bus_width == 16) {
1481                 nand->busw = 16;
1482                 chip->options |= NAND_BUSWIDTH_16;
1483         }
1484
1485         nsmtd->owner = THIS_MODULE;
1486
1487         if ((retval = nand_scan(nsmtd, 1)) != 0) {
1488                 NS_ERR("can't register NAND Simulator\n");
1489                 if (retval > 0)
1490                         retval = -ENXIO;
1491                 goto error;
1492         }
1493
1494         if ((retval = init_nandsim(nsmtd)) != 0) {
1495                 NS_ERR("scan_bbt: can't initialize the nandsim structure\n");
1496                 goto error;
1497         }
1498
1499         if ((retval = nand_default_bbt(nsmtd)) != 0) {
1500                 free_nandsim(nand);
1501                 goto error;
1502         }
1503
1504         /* Register NAND as one big partition */
1505         add_mtd_partitions(nsmtd, &nand->part, 1);
1506
1507         return 0;
1508
1509 error:
1510         kfree(nsmtd);
1511
1512         return retval;
1513 }
1514
1515 module_init(ns_init_module);
1516
1517 /*
1518  * Module clean-up function
1519  */
1520 static void __exit ns_cleanup_module(void)
1521 {
1522         struct nandsim *ns = (struct nandsim *)(((struct nand_chip *)nsmtd->priv)->priv);
1523
1524         free_nandsim(ns);    /* Free nandsim private resources */
1525         nand_release(nsmtd); /* Unregisterd drived */
1526         kfree(nsmtd);        /* Free other structures */
1527 }
1528
1529 module_exit(ns_cleanup_module);
1530
1531 MODULE_LICENSE ("GPL");
1532 MODULE_AUTHOR ("Artem B. Bityuckiy");
1533 MODULE_DESCRIPTION ("The NAND flash simulator");
1534