kernel/drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c

   1 /*
   2  * BCM47XX NAND flash driver
   3  *
   4  * Copyright (C) 2012 Rafał Miłecki <zajec5@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include "bcm47xxnflash.h"
  13
  14 #include <linux/module.h>
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/delay.h>
  18 #include <linux/bcma/bcma.h>
  19
  20 /* Broadcom uses 1'000'000 but it seems to be too many. Tests on WNDR4500 has
  21  * shown ~1000 retries as maxiumum. */
  22 #define NFLASH_READY_RETRIES            10000
  23
  24 #define NFLASH_SECTOR_SIZE              512
  25
  26 #define NCTL_CMD0                       0x00010000
  27 #define NCTL_COL                        0x00020000      /* Update column with value from BCMA_CC_NFLASH_COL_ADDR */
  28 #define NCTL_ROW                        0x00040000      /* Update row (page) with value from BCMA_CC_NFLASH_ROW_ADDR */
  29 #define NCTL_CMD1W                      0x00080000
  30 #define NCTL_READ                       0x00100000
  31 #define NCTL_WRITE                      0x00200000
  32 #define NCTL_SPECADDR                   0x01000000
  33 #define NCTL_READY                      0x04000000
  34 #define NCTL_ERR                        0x08000000
  35 #define NCTL_CSA                        0x40000000
  36 #define NCTL_START                      0x80000000
  37
  38 /**************************************************
  39  * Various helpers
  40  **************************************************/
  41
  42 static inline u8 bcm47xxnflash_ops_bcm4706_ns_to_cycle(u16 ns, u16 clock)
  43 {
  44         return ((ns * 1000 * clock) / 1000000) + 1;
  45 }
  46
  47 static int bcm47xxnflash_ops_bcm4706_ctl_cmd(struct bcma_drv_cc *cc, u32 code)
  48 {
  49         int i = 0;
  50
  51         bcma_cc_write32(cc, BCMA_CC_NFLASH_CTL, NCTL_START | code);
  52         for (i = 0; i < NFLASH_READY_RETRIES; i++) {
  53                 if (!(bcma_cc_read32(cc, BCMA_CC_NFLASH_CTL) & NCTL_START)) {
  54                         i = 0;
  55                         break;
  56                 }
  57         }
  58         if (i) {
  59                 pr_err("NFLASH control command not ready!\n");
  60                 return -EBUSY;
  61         }
  62         return 0;
  63 }
  64
  65 static int bcm47xxnflash_ops_bcm4706_poll(struct bcma_drv_cc *cc)
  66 {
  67         int i;
  68
  69         for (i = 0; i < NFLASH_READY_RETRIES; i++) {
  70                 if (bcma_cc_read32(cc, BCMA_CC_NFLASH_CTL) & NCTL_READY) {
  71                         if (bcma_cc_read32(cc, BCMA_CC_NFLASH_CTL) &
  72                             BCMA_CC_NFLASH_CTL_ERR) {
  73                                 pr_err("Error on polling\n");
  74                                 return -EBUSY;
  75                         } else {
  76                                 return 0;
  77                         }
  78                 }
  79         }
  80
  81         pr_err("Polling timeout!\n");
  82         return -EBUSY;
  83 }
  84
  85 /**************************************************
  86  * R/W
  87  **************************************************/
  88
  89 static void bcm47xxnflash_ops_bcm4706_read(struct mtd_info *mtd, uint8_t *buf,
  90                                            int len)
  91 {
  92         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
  93         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
  94
  95         u32 ctlcode;
  96         u32 *dest = (u32 *)buf;
  97         int i;
  98         int toread;
  99
 100         BUG_ON(b47n->curr_page_addr & ~nand_chip->pagemask);
 101         /* Don't validate column using nand_chip->page_shift, it may be bigger
 102          * when accessing OOB */
 103
 104         while (len) {
 105                 /* We can read maximum of 0x200 bytes at once */
 106                 toread = min(len, 0x200);
 107
 108                 /* Set page and column */
 109                 bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_COL_ADDR,
 110                                 b47n->curr_column);
 111                 bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_ROW_ADDR,
 112                                 b47n->curr_page_addr);
 113
 114                 /* Prepare to read */
 115                 ctlcode = NCTL_CSA | NCTL_CMD1W | NCTL_ROW | NCTL_COL |
 116                           NCTL_CMD0;
 117                 ctlcode |= NAND_CMD_READSTART << 8;
 118                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc, ctlcode))
 119                         return;
 120                 if (bcm47xxnflash_ops_bcm4706_poll(b47n->cc))
 121                         return;
 122
 123                 /* Eventually read some data :) */
 124                 for (i = 0; i < toread; i += 4, dest++) {
 125                         ctlcode = NCTL_CSA | 0x30000000 | NCTL_READ;
 126                         if (i == toread - 4) /* Last read goes without that */
 127                                 ctlcode &= ~NCTL_CSA;
 128                         if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc,
 129                                                               ctlcode))
 130                                 return;
 131                         *dest = bcma_cc_read32(b47n->cc, BCMA_CC_NFLASH_DATA);
 132                 }
 133
 134                 b47n->curr_column += toread;
 135                 len -= toread;
 136         }
 137 }
 138
 139 static void bcm47xxnflash_ops_bcm4706_write(struct mtd_info *mtd,
 140                                             const uint8_t *buf, int len)
 141 {
 142         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 143         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 144         struct bcma_drv_cc *cc = b47n->cc;
 145
 146         u32 ctlcode;
 147         const u32 *data = (u32 *)buf;
 148         int i;
 149
 150         BUG_ON(b47n->curr_page_addr & ~nand_chip->pagemask);
 151         /* Don't validate column using nand_chip->page_shift, it may be bigger
 152          * when accessing OOB */
 153
 154         for (i = 0; i < len; i += 4, data++) {
 155                 bcma_cc_write32(cc, BCMA_CC_NFLASH_DATA, *data);
 156
 157                 ctlcode = NCTL_CSA | 0x30000000 | NCTL_WRITE;
 158                 if (i == len - 4) /* Last read goes without that */
 159                         ctlcode &= ~NCTL_CSA;
 160                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, ctlcode)) {
 161                         pr_err("%s ctl_cmd didn't work!\n", __func__);
 162                         return;
 163                 }
 164         }
 165
 166         b47n->curr_column += len;
 167 }
 168
 169 /**************************************************
 170  * NAND chip ops
 171  **************************************************/
 172
 173 static void bcm47xxnflash_ops_bcm4706_cmd_ctrl(struct mtd_info *mtd, int cmd,
 174                                                unsigned int ctrl)
 175 {
 176         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 177         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 178         u32 code = 0;
 179
 180         if (cmd == NAND_CMD_NONE)
 181                 return;
 182
 183         if (cmd & NAND_CTRL_CLE)
 184                 code = cmd | NCTL_CMD0;
 185
 186         /* nCS is not needed for reset command */
 187         if (cmd != NAND_CMD_RESET)
 188                 code |= NCTL_CSA;
 189
 190         bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc, code);
 191 }
 192
 193 /* Default nand_select_chip calls cmd_ctrl, which is not used in BCM4706 */
 194 static void bcm47xxnflash_ops_bcm4706_select_chip(struct mtd_info *mtd,
 195                                                   int chip)
 196 {
 197         return;
 198 }
 199
 200 static int bcm47xxnflash_ops_bcm4706_dev_ready(struct mtd_info *mtd)
 201 {
 202         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 203         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 204
 205         return !!(bcma_cc_read32(b47n->cc, BCMA_CC_NFLASH_CTL) & NCTL_READY);
 206 }
 207
 208 /*
 209  * Default nand_command and nand_command_lp don't match BCM4706 hardware layout.
 210  * For example, reading chip id is performed in a non-standard way.
 211  * Setting column and page is also handled differently, we use a special
 212  * registers of ChipCommon core. Hacking cmd_ctrl to understand and convert
 213  * standard commands would be much more complicated.
 214  */
 215 static void bcm47xxnflash_ops_bcm4706_cmdfunc(struct mtd_info *mtd,
 216                                               unsigned command, int column,
 217                                               int page_addr)
 218 {
 219         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 220         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 221         struct bcma_drv_cc *cc = b47n->cc;
 222         u32 ctlcode;
 223         int i;
 224
 225         if (column != -1)
 226                 b47n->curr_column = column;
 227         if (page_addr != -1)
 228                 b47n->curr_page_addr = page_addr;
 229
 230         switch (command) {
 231         case NAND_CMD_RESET:
 232                 nand_chip->cmd_ctrl(mtd, command, NAND_CTRL_CLE);
 233
 234                 ndelay(100);
 235                 nand_wait_ready(mtd);
 236                 break;
 237         case NAND_CMD_READID:
 238                 ctlcode = NCTL_CSA | 0x01000000 | NCTL_CMD1W | NCTL_CMD0;
 239                 ctlcode |= NAND_CMD_READID;
 240                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc, ctlcode)) {
 241                         pr_err("READID error\n");
 242                         break;
 243                 }
 244
 245                 /*
 246                  * Reading is specific, last one has to go without NCTL_CSA
 247                  * bit. We don't know how many reads NAND subsystem is going
 248                  * to perform, so cache everything.
 249                  */
 250                 for (i = 0; i < ARRAY_SIZE(b47n->id_data); i++) {
 251                         ctlcode = NCTL_CSA | NCTL_READ;
 252                         if (i == ARRAY_SIZE(b47n->id_data) - 1)
 253                                 ctlcode &= ~NCTL_CSA;
 254                         if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc,
 255                                                               ctlcode)) {
 256                                 pr_err("READID error\n");
 257                                 break;
 258                         }
 259                         b47n->id_data[i] =
 260                                 bcma_cc_read32(b47n->cc, BCMA_CC_NFLASH_DATA)
 261                                 & 0xFF;
 262                 }
 263
 264                 break;
 265         case NAND_CMD_STATUS:
 266                 ctlcode = NCTL_CSA | NCTL_CMD0 | NAND_CMD_STATUS;
 267                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, ctlcode))
 268                         pr_err("STATUS command error\n");
 269                 break;
 270         case NAND_CMD_READ0:
 271                 break;
 272         case NAND_CMD_READOOB:
 273                 if (page_addr != -1)
 274                         b47n->curr_column += mtd->writesize;
 275                 break;
 276         case NAND_CMD_ERASE1:
 277                 bcma_cc_write32(cc, BCMA_CC_NFLASH_ROW_ADDR,
 278                                 b47n->curr_page_addr);
 279                 ctlcode = NCTL_ROW | NCTL_CMD1W | NCTL_CMD0 |
 280                           NAND_CMD_ERASE1 | (NAND_CMD_ERASE2 << 8);
 281                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, ctlcode))
 282                         pr_err("ERASE1 failed\n");
 283                 break;
 284         case NAND_CMD_ERASE2:
 285                 break;
 286         case NAND_CMD_SEQIN:
 287                 /* Set page and column */
 288                 bcma_cc_write32(cc, BCMA_CC_NFLASH_COL_ADDR,
 289                                 b47n->curr_column);
 290                 bcma_cc_write32(cc, BCMA_CC_NFLASH_ROW_ADDR,
 291                                 b47n->curr_page_addr);
 292
 293                 /* Prepare to write */
 294                 ctlcode = 0x40000000 | NCTL_ROW | NCTL_COL | NCTL_CMD0;
 295                 ctlcode |= NAND_CMD_SEQIN;
 296                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, ctlcode))
 297                         pr_err("SEQIN failed\n");
 298                 break;
 299         case NAND_CMD_PAGEPROG:
 300                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, NCTL_CMD0 |
 301                                                           NAND_CMD_PAGEPROG))
 302                         pr_err("PAGEPROG failed\n");
 303                 if (bcm47xxnflash_ops_bcm4706_poll(cc))
 304                         pr_err("PAGEPROG not ready\n");
 305                 break;
 306         default:
 307                 pr_err("Command 0x%X unsupported\n", command);
 308                 break;
 309         }
 310         b47n->curr_command = command;
 311 }
 312
 313 static u8 bcm47xxnflash_ops_bcm4706_read_byte(struct mtd_info *mtd)
 314 {
 315         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 316         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 317         struct bcma_drv_cc *cc = b47n->cc;
 318         u32 tmp = 0;
 319
 320         switch (b47n->curr_command) {
 321         case NAND_CMD_READID:
 322                 if (b47n->curr_column >= ARRAY_SIZE(b47n->id_data)) {
 323                         pr_err("Requested invalid id_data: %d\n",
 324                                b47n->curr_column);
 325                         return 0;
 326                 }
 327                 return b47n->id_data[b47n->curr_column++];
 328         case NAND_CMD_STATUS:
 329                 if (bcm47xxnflash_ops_bcm4706_ctl_cmd(cc, NCTL_READ))
 330                         return 0;
 331                 return bcma_cc_read32(cc, BCMA_CC_NFLASH_DATA) & 0xff;
 332         case NAND_CMD_READOOB:
 333                 bcm47xxnflash_ops_bcm4706_read(mtd, (u8 *)&tmp, 4);
 334                 return tmp & 0xFF;
 335         }
 336
 337         pr_err("Invalid command for byte read: 0x%X\n", b47n->curr_command);
 338         return 0;
 339 }
 340
 341 static void bcm47xxnflash_ops_bcm4706_read_buf(struct mtd_info *mtd,
 342                                                uint8_t *buf, int len)
 343 {
 344         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 345         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 346
 347         switch (b47n->curr_command) {
 348         case NAND_CMD_READ0:
 349         case NAND_CMD_READOOB:
 350                 bcm47xxnflash_ops_bcm4706_read(mtd, buf, len);
 351                 return;
 352         }
 353
 354         pr_err("Invalid command for buf read: 0x%X\n", b47n->curr_command);
 355 }
 356
 357 static void bcm47xxnflash_ops_bcm4706_write_buf(struct mtd_info *mtd,
 358                                                 const uint8_t *buf, int len)
 359 {
 360         struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
 361         struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
 362
 363         switch (b47n->curr_command) {
 364         case NAND_CMD_SEQIN:
 365                 bcm47xxnflash_ops_bcm4706_write(mtd, buf, len);
 366                 return;
 367         }
 368
 369         pr_err("Invalid command for buf write: 0x%X\n", b47n->curr_command);
 370 }
 371
 372 /**************************************************
 373  * Init
 374  **************************************************/
 375
 376 int bcm47xxnflash_ops_bcm4706_init(struct bcm47xxnflash *b47n)
 377 {
 378         struct nand_chip *nand_chip = (struct nand_chip *)&b47n->nand_chip;
 379         int err;
 380         u32 freq;
 381         u16 clock;
 382         u8 w0, w1, w2, w3, w4;
 383
 384         unsigned long chipsize; /* MiB */
 385         u8 tbits, col_bits, col_size, row_bits, row_bsize;
 386         u32 val;
 387
 388         b47n->nand_chip.select_chip = bcm47xxnflash_ops_bcm4706_select_chip;
 389         nand_chip->cmd_ctrl = bcm47xxnflash_ops_bcm4706_cmd_ctrl;
 390         nand_chip->dev_ready = bcm47xxnflash_ops_bcm4706_dev_ready;
 391         b47n->nand_chip.cmdfunc = bcm47xxnflash_ops_bcm4706_cmdfunc;
 392         b47n->nand_chip.read_byte = bcm47xxnflash_ops_bcm4706_read_byte;
 393         b47n->nand_chip.read_buf = bcm47xxnflash_ops_bcm4706_read_buf;
 394         b47n->nand_chip.write_buf = bcm47xxnflash_ops_bcm4706_write_buf;
 395
 396         nand_chip->chip_delay = 50;
 397         b47n->nand_chip.bbt_options = NAND_BBT_USE_FLASH;
 398         b47n->nand_chip.ecc.mode = NAND_ECC_NONE; /* TODO: implement ECC */
 399
 400         /* Enable NAND flash access */
 401         bcma_cc_set32(b47n->cc, BCMA_CC_4706_FLASHSCFG,
 402                       BCMA_CC_4706_FLASHSCFG_NF1);
 403
 404         /* Configure wait counters */
 405         if (b47n->cc->status & BCMA_CC_CHIPST_4706_PKG_OPTION) {
 406                 /* 400 MHz */
 407                 freq = 400000000 / 4;
 408         } else {
 409                 freq = bcma_chipco_pll_read(b47n->cc, 4);
 410                 freq = (freq & 0xFFF) >> 3;
 411                 /* Fixed reference clock 25 MHz and m = 2 */
 412                 freq = (freq * 25000000 / 2) / 4;
 413         }
 414         clock = freq / 1000000;
 415         w0 = bcm47xxnflash_ops_bcm4706_ns_to_cycle(15, clock);
 416         w1 = bcm47xxnflash_ops_bcm4706_ns_to_cycle(20, clock);
 417         w2 = bcm47xxnflash_ops_bcm4706_ns_to_cycle(10, clock);
 418         w3 = bcm47xxnflash_ops_bcm4706_ns_to_cycle(10, clock);
 419         w4 = bcm47xxnflash_ops_bcm4706_ns_to_cycle(100, clock);
 420         bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_WAITCNT0,
 421                         (w4 << 24 | w3 << 18 | w2 << 12 | w1 << 6 | w0));
 422
 423         /* Scan NAND */
 424         err = nand_scan(&b47n->mtd, 1);
 425         if (err) {
 426                 pr_err("Could not scan NAND flash: %d\n", err);
 427                 goto exit;
 428         }
 429
 430         /* Configure FLASH */
 431         chipsize = b47n->nand_chip.chipsize >> 20;
 432         tbits = ffs(chipsize); /* find first bit set */
 433         if (!tbits || tbits != fls(chipsize)) {
 434                 pr_err("Invalid flash size: 0x%lX\n", chipsize);
 435                 err = -ENOTSUPP;
 436                 goto exit;
 437         }
 438         tbits += 19; /* Broadcom increases *index* by 20, we increase *pos* */
 439
 440         col_bits = b47n->nand_chip.page_shift + 1;
 441         col_size = (col_bits + 7) / 8;
 442
 443         row_bits = tbits - col_bits + 1;
 444         row_bsize = (row_bits + 7) / 8;
 445
 446         val = ((row_bsize - 1) << 6) | ((col_size - 1) << 4) | 2;
 447         bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_CONF, val);
 448
 449 exit:
 450         if (err)
 451                 bcma_cc_mask32(b47n->cc, BCMA_CC_4706_FLASHSCFG,
 452                                ~BCMA_CC_4706_FLASHSCFG_NF1);
 453         return err;
 454 }