drivers/mtd/nand/omap2.c

   1 /*
   2  * Copyright © 2004 Texas Instruments, Jian Zhang <jzhang@ti.com>
   3  * Copyright © 2004 Micron Technology Inc.
   4  * Copyright © 2004 David Brownell
   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 #include <linux/platform_device.h>
  12 #include <linux/dmaengine.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/delay.h>
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/sched.h>
  19 #include <linux/mtd/mtd.h>
  20 #include <linux/mtd/nand.h>
  21 #include <linux/mtd/partitions.h>
  22 #include <linux/omap-dma.h>
  23 #include <linux/io.h>
  24 #include <linux/slab.h>
  25
  26 #ifdef CONFIG_MTD_NAND_OMAP_BCH
  27 #include <linux/bch.h>
  28 #endif
  29
  30 #include <linux/platform_data/mtd-nand-omap2.h>
  31
  32 #define DRIVER_NAME     "omap2-nand"
  33 #define OMAP_NAND_TIMEOUT_MS    5000
  34
  35 #define NAND_Ecc_P1e            (1 << 0)
  36 #define NAND_Ecc_P2e            (1 << 1)
  37 #define NAND_Ecc_P4e            (1 << 2)
  38 #define NAND_Ecc_P8e            (1 << 3)
  39 #define NAND_Ecc_P16e           (1 << 4)
  40 #define NAND_Ecc_P32e           (1 << 5)
  41 #define NAND_Ecc_P64e           (1 << 6)
  42 #define NAND_Ecc_P128e          (1 << 7)
  43 #define NAND_Ecc_P256e          (1 << 8)
  44 #define NAND_Ecc_P512e          (1 << 9)
  45 #define NAND_Ecc_P1024e         (1 << 10)
  46 #define NAND_Ecc_P2048e         (1 << 11)
  47
  48 #define NAND_Ecc_P1o            (1 << 16)
  49 #define NAND_Ecc_P2o            (1 << 17)
  50 #define NAND_Ecc_P4o            (1 << 18)
  51 #define NAND_Ecc_P8o            (1 << 19)
  52 #define NAND_Ecc_P16o           (1 << 20)
  53 #define NAND_Ecc_P32o           (1 << 21)
  54 #define NAND_Ecc_P64o           (1 << 22)
  55 #define NAND_Ecc_P128o          (1 << 23)
  56 #define NAND_Ecc_P256o          (1 << 24)
  57 #define NAND_Ecc_P512o          (1 << 25)
  58 #define NAND_Ecc_P1024o         (1 << 26)
  59 #define NAND_Ecc_P2048o         (1 << 27)
  60
  61 #define TF(value)       (value ? 1 : 0)
  62
  63 #define P2048e(a)       (TF(a & NAND_Ecc_P2048e)        << 0)
  64 #define P2048o(a)       (TF(a & NAND_Ecc_P2048o)        << 1)
  65 #define P1e(a)          (TF(a & NAND_Ecc_P1e)           << 2)
  66 #define P1o(a)          (TF(a & NAND_Ecc_P1o)           << 3)
  67 #define P2e(a)          (TF(a & NAND_Ecc_P2e)           << 4)
  68 #define P2o(a)          (TF(a & NAND_Ecc_P2o)           << 5)
  69 #define P4e(a)          (TF(a & NAND_Ecc_P4e)           << 6)
  70 #define P4o(a)          (TF(a & NAND_Ecc_P4o)           << 7)
  71
  72 #define P8e(a)          (TF(a & NAND_Ecc_P8e)           << 0)
  73 #define P8o(a)          (TF(a & NAND_Ecc_P8o)           << 1)
  74 #define P16e(a)         (TF(a & NAND_Ecc_P16e)          << 2)
  75 #define P16o(a)         (TF(a & NAND_Ecc_P16o)          << 3)
  76 #define P32e(a)         (TF(a & NAND_Ecc_P32e)          << 4)
  77 #define P32o(a)         (TF(a & NAND_Ecc_P32o)          << 5)
  78 #define P64e(a)         (TF(a & NAND_Ecc_P64e)          << 6)
  79 #define P64o(a)         (TF(a & NAND_Ecc_P64o)          << 7)
  80
  81 #define P128e(a)        (TF(a & NAND_Ecc_P128e)         << 0)
  82 #define P128o(a)        (TF(a & NAND_Ecc_P128o)         << 1)
  83 #define P256e(a)        (TF(a & NAND_Ecc_P256e)         << 2)
  84 #define P256o(a)        (TF(a & NAND_Ecc_P256o)         << 3)
  85 #define P512e(a)        (TF(a & NAND_Ecc_P512e)         << 4)
  86 #define P512o(a)        (TF(a & NAND_Ecc_P512o)         << 5)
  87 #define P1024e(a)       (TF(a & NAND_Ecc_P1024e)        << 6)
  88 #define P1024o(a)       (TF(a & NAND_Ecc_P1024o)        << 7)
  89
  90 #define P8e_s(a)        (TF(a & NAND_Ecc_P8e)           << 0)
  91 #define P8o_s(a)        (TF(a & NAND_Ecc_P8o)           << 1)
  92 #define P16e_s(a)       (TF(a & NAND_Ecc_P16e)          << 2)
  93 #define P16o_s(a)       (TF(a & NAND_Ecc_P16o)          << 3)
  94 #define P1e_s(a)        (TF(a & NAND_Ecc_P1e)           << 4)
  95 #define P1o_s(a)        (TF(a & NAND_Ecc_P1o)           << 5)
  96 #define P2e_s(a)        (TF(a & NAND_Ecc_P2e)           << 6)
  97 #define P2o_s(a)        (TF(a & NAND_Ecc_P2o)           << 7)
  98
  99 #define P4e_s(a)        (TF(a & NAND_Ecc_P4e)           << 0)
 100 #define P4o_s(a)        (TF(a & NAND_Ecc_P4o)           << 1)
 101
 102 #define PREFETCH_CONFIG1_CS_SHIFT       24
 103 #define ECC_CONFIG_CS_SHIFT             1
 104 #define CS_MASK                         0x7
 105 #define ENABLE_PREFETCH                 (0x1 << 7)
 106 #define DMA_MPU_MODE_SHIFT              2
 107 #define ECCSIZE0_SHIFT                  12
 108 #define ECCSIZE1_SHIFT                  22
 109 #define ECC1RESULTSIZE                  0x1
 110 #define ECCCLEAR                        0x100
 111 #define ECC1                            0x1
 112 #define PREFETCH_FIFOTHRESHOLD_MAX      0x40
 113 #define PREFETCH_FIFOTHRESHOLD(val)     ((val) << 8)
 114 #define PREFETCH_STATUS_COUNT(val)      (val & 0x00003fff)
 115 #define PREFETCH_STATUS_FIFO_CNT(val)   ((val >> 24) & 0x7F)
 116 #define STATUS_BUFF_EMPTY               0x00000001
 117
 118 #define OMAP24XX_DMA_GPMC               4
 119
 120 /* oob info generated runtime depending on ecc algorithm and layout selected */
 121 static struct nand_ecclayout omap_oobinfo;
 122 /* Define some generic bad / good block scan pattern which are used
 123  * while scanning a device for factory marked good / bad blocks
 124  */
 125 static uint8_t scan_ff_pattern[] = { 0xff };
 126 static struct nand_bbt_descr bb_descrip_flashbased = {
 127         .options = NAND_BBT_SCANEMPTY | NAND_BBT_SCANALLPAGES,
 128         .offs = 0,
 129         .len = 1,
 130         .pattern = scan_ff_pattern,
 131 };
 132
 133
 134 struct omap_nand_info {
 135         struct nand_hw_control          controller;
 136         struct omap_nand_platform_data  *pdata;
 137         struct mtd_info                 mtd;
 138         struct nand_chip                nand;
 139         struct platform_device          *pdev;
 140
 141         int                             gpmc_cs;
 142         unsigned long                   phys_base;
 143         unsigned long                   mem_size;
 144         struct completion               comp;
 145         struct dma_chan                 *dma;
 146         int                             gpmc_irq_fifo;
 147         int                             gpmc_irq_count;
 148         enum {
 149                 OMAP_NAND_IO_READ = 0,  /* read */
 150                 OMAP_NAND_IO_WRITE,     /* write */
 151         } iomode;
 152         u_char                          *buf;
 153         int                                     buf_len;
 154         struct gpmc_nand_regs           reg;
 155
 156 #ifdef CONFIG_MTD_NAND_OMAP_BCH
 157         struct bch_control             *bch;
 158         struct nand_ecclayout           ecclayout;
 159 #endif
 160 };
 161
 162 /**
 163  * omap_prefetch_enable - configures and starts prefetch transfer
 164  * @cs: cs (chip select) number
 165  * @fifo_th: fifo threshold to be used for read/ write
 166  * @dma_mode: dma mode enable (1) or disable (0)
 167  * @u32_count: number of bytes to be transferred
 168  * @is_write: prefetch read(0) or write post(1) mode
 169  */
 170 static int omap_prefetch_enable(int cs, int fifo_th, int dma_mode,
 171         unsigned int u32_count, int is_write, struct omap_nand_info *info)
 172 {
 173         u32 val;
 174
 175         if (fifo_th > PREFETCH_FIFOTHRESHOLD_MAX)
 176                 return -1;
 177
 178         if (readl(info->reg.gpmc_prefetch_control))
 179                 return -EBUSY;
 180
 181         /* Set the amount of bytes to be prefetched */
 182         writel(u32_count, info->reg.gpmc_prefetch_config2);
 183
 184         /* Set dma/mpu mode, the prefetch read / post write and
 185          * enable the engine. Set which cs is has requested for.
 186          */
 187         val = ((cs << PREFETCH_CONFIG1_CS_SHIFT) |
 188                 PREFETCH_FIFOTHRESHOLD(fifo_th) | ENABLE_PREFETCH |
 189                 (dma_mode << DMA_MPU_MODE_SHIFT) | (0x1 & is_write));
 190         writel(val, info->reg.gpmc_prefetch_config1);
 191
 192         /*  Start the prefetch engine */
 193         writel(0x1, info->reg.gpmc_prefetch_control);
 194
 195         return 0;
 196 }
 197
 198 /**
 199  * omap_prefetch_reset - disables and stops the prefetch engine
 200  */
 201 static int omap_prefetch_reset(int cs, struct omap_nand_info *info)
 202 {
 203         u32 config1;
 204
 205         /* check if the same module/cs is trying to reset */
 206         config1 = readl(info->reg.gpmc_prefetch_config1);
 207         if (((config1 >> PREFETCH_CONFIG1_CS_SHIFT) & CS_MASK) != cs)
 208                 return -EINVAL;
 209
 210         /* Stop the PFPW engine */
 211         writel(0x0, info->reg.gpmc_prefetch_control);
 212
 213         /* Reset/disable the PFPW engine */
 214         writel(0x0, info->reg.gpmc_prefetch_config1);
 215
 216         return 0;
 217 }
 218
 219 /**
 220  * omap_hwcontrol - hardware specific access to control-lines
 221  * @mtd: MTD device structure
 222  * @cmd: command to device
 223  * @ctrl:
 224  * NAND_NCE: bit 0 -> don't care
 225  * NAND_CLE: bit 1 -> Command Latch
 226  * NAND_ALE: bit 2 -> Address Latch
 227  *
 228  * NOTE: boards may use different bits for these!!
 229  */
 230 static void omap_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
 231 {
 232         struct omap_nand_info *info = container_of(mtd,
 233                                         struct omap_nand_info, mtd);
 234
 235         if (cmd != NAND_CMD_NONE) {
 236                 if (ctrl & NAND_CLE)
 237                         writeb(cmd, info->reg.gpmc_nand_command);
 238
 239                 else if (ctrl & NAND_ALE)
 240                         writeb(cmd, info->reg.gpmc_nand_address);
 241
 242                 else /* NAND_NCE */
 243                         writeb(cmd, info->reg.gpmc_nand_data);
 244         }
 245 }
 246
 247 /**
 248  * omap_read_buf8 - read data from NAND controller into buffer
 249  * @mtd: MTD device structure
 250  * @buf: buffer to store date
 251  * @len: number of bytes to read
 252  */
 253 static void omap_read_buf8(struct mtd_info *mtd, u_char *buf, int len)
 254 {
 255         struct nand_chip *nand = mtd->priv;
 256
 257         ioread8_rep(nand->IO_ADDR_R, buf, len);
 258 }
 259
 260 /**
 261  * omap_write_buf8 - write buffer to NAND controller
 262  * @mtd: MTD device structure
 263  * @buf: data buffer
 264  * @len: number of bytes to write
 265  */
 266 static void omap_write_buf8(struct mtd_info *mtd, const u_char *buf, int len)
 267 {
 268         struct omap_nand_info *info = container_of(mtd,
 269                                                 struct omap_nand_info, mtd);
 270         u_char *p = (u_char *)buf;
 271         u32     status = 0;
 272
 273         while (len--) {
 274                 iowrite8(*p++, info->nand.IO_ADDR_W);
 275                 /* wait until buffer is available for write */
 276                 do {
 277                         status = readl(info->reg.gpmc_status) &
 278                                         STATUS_BUFF_EMPTY;
 279                 } while (!status);
 280         }
 281 }
 282
 283 /**
 284  * omap_read_buf16 - read data from NAND controller into buffer
 285  * @mtd: MTD device structure
 286  * @buf: buffer to store date
 287  * @len: number of bytes to read
 288  */
 289 static void omap_read_buf16(struct mtd_info *mtd, u_char *buf, int len)
 290 {
 291         struct nand_chip *nand = mtd->priv;
 292
 293         ioread16_rep(nand->IO_ADDR_R, buf, len / 2);
 294 }
 295
 296 /**
 297  * omap_write_buf16 - write buffer to NAND controller
 298  * @mtd: MTD device structure
 299  * @buf: data buffer
 300  * @len: number of bytes to write
 301  */
 302 static void omap_write_buf16(struct mtd_info *mtd, const u_char * buf, int len)
 303 {
 304         struct omap_nand_info *info = container_of(mtd,
 305                                                 struct omap_nand_info, mtd);
 306         u16 *p = (u16 *) buf;
 307         u32     status = 0;
 308         /* FIXME try bursts of writesw() or DMA ... */
 309         len >>= 1;
 310
 311         while (len--) {
 312                 iowrite16(*p++, info->nand.IO_ADDR_W);
 313                 /* wait until buffer is available for write */
 314                 do {
 315                         status = readl(info->reg.gpmc_status) &
 316                                         STATUS_BUFF_EMPTY;
 317                 } while (!status);
 318         }
 319 }
 320
 321 /**
 322  * omap_read_buf_pref - read data from NAND controller into buffer
 323  * @mtd: MTD device structure
 324  * @buf: buffer to store date
 325  * @len: number of bytes to read
 326  */
 327 static void omap_read_buf_pref(struct mtd_info *mtd, u_char *buf, int len)
 328 {
 329         struct omap_nand_info *info = container_of(mtd,
 330                                                 struct omap_nand_info, mtd);
 331         uint32_t r_count = 0;
 332         int ret = 0;
 333         u32 *p = (u32 *)buf;
 334
 335         /* take care of subpage reads */
 336         if (len % 4) {
 337                 if (info->nand.options & NAND_BUSWIDTH_16)
 338                         omap_read_buf16(mtd, buf, len % 4);
 339                 else
 340                         omap_read_buf8(mtd, buf, len % 4);
 341                 p = (u32 *) (buf + len % 4);
 342                 len -= len % 4;
 343         }
 344
 345         /* configure and start prefetch transfer */
 346         ret = omap_prefetch_enable(info->gpmc_cs,
 347                         PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x0, info);
 348         if (ret) {
 349                 /* PFPW engine is busy, use cpu copy method */
 350                 if (info->nand.options & NAND_BUSWIDTH_16)
 351                         omap_read_buf16(mtd, (u_char *)p, len);
 352                 else
 353                         omap_read_buf8(mtd, (u_char *)p, len);
 354         } else {
 355                 do {
 356                         r_count = readl(info->reg.gpmc_prefetch_status);
 357                         r_count = PREFETCH_STATUS_FIFO_CNT(r_count);
 358                         r_count = r_count >> 2;
 359                         ioread32_rep(info->nand.IO_ADDR_R, p, r_count);
 360                         p += r_count;
 361                         len -= r_count << 2;
 362                 } while (len);
 363                 /* disable and stop the PFPW engine */
 364                 omap_prefetch_reset(info->gpmc_cs, info);
 365         }
 366 }
 367
 368 /**
 369  * omap_write_buf_pref - write buffer to NAND controller
 370  * @mtd: MTD device structure
 371  * @buf: data buffer
 372  * @len: number of bytes to write
 373  */
 374 static void omap_write_buf_pref(struct mtd_info *mtd,
 375                                         const u_char *buf, int len)
 376 {
 377         struct omap_nand_info *info = container_of(mtd,
 378                                                 struct omap_nand_info, mtd);
 379         uint32_t w_count = 0;
 380         int i = 0, ret = 0;
 381         u16 *p = (u16 *)buf;
 382         unsigned long tim, limit;
 383         u32 val;
 384
 385         /* take care of subpage writes */
 386         if (len % 2 != 0) {
 387                 writeb(*buf, info->nand.IO_ADDR_W);
 388                 p = (u16 *)(buf + 1);
 389                 len--;
 390         }
 391
 392         /*  configure and start prefetch transfer */
 393         ret = omap_prefetch_enable(info->gpmc_cs,
 394                         PREFETCH_FIFOTHRESHOLD_MAX, 0x0, len, 0x1, info);
 395         if (ret) {
 396                 /* PFPW engine is busy, use cpu copy method */
 397                 if (info->nand.options & NAND_BUSWIDTH_16)
 398                         omap_write_buf16(mtd, (u_char *)p, len);
 399                 else
 400                         omap_write_buf8(mtd, (u_char *)p, len);
 401         } else {
 402                 while (len) {
 403                         w_count = readl(info->reg.gpmc_prefetch_status);
 404                         w_count = PREFETCH_STATUS_FIFO_CNT(w_count);
 405                         w_count = w_count >> 1;
 406                         for (i = 0; (i < w_count) && len; i++, len -= 2)
 407                                 iowrite16(*p++, info->nand.IO_ADDR_W);
 408                 }
 409                 /* wait for data to flushed-out before reset the prefetch */
 410                 tim = 0;
 411                 limit = (loops_per_jiffy *
 412                                         msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
 413                 do {
 414                         cpu_relax();
 415                         val = readl(info->reg.gpmc_prefetch_status);
 416                         val = PREFETCH_STATUS_COUNT(val);
 417                 } while (val && (tim++ < limit));
 418
 419                 /* disable and stop the PFPW engine */
 420                 omap_prefetch_reset(info->gpmc_cs, info);
 421         }
 422 }
 423
 424 /*
 425  * omap_nand_dma_callback: callback on the completion of dma transfer
 426  * @data: pointer to completion data structure
 427  */
 428 static void omap_nand_dma_callback(void *data)
 429 {
 430         complete((struct completion *) data);
 431 }
 432
 433 /*
 434  * omap_nand_dma_transfer: configure and start dma transfer
 435  * @mtd: MTD device structure
 436  * @addr: virtual address in RAM of source/destination
 437  * @len: number of data bytes to be transferred
 438  * @is_write: flag for read/write operation
 439  */
 440 static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr,
 441                                         unsigned int len, int is_write)
 442 {
 443         struct omap_nand_info *info = container_of(mtd,
 444                                         struct omap_nand_info, mtd);
 445         struct dma_async_tx_descriptor *tx;
 446         enum dma_data_direction dir = is_write ? DMA_TO_DEVICE :
 447                                                         DMA_FROM_DEVICE;
 448         struct scatterlist sg;
 449         unsigned long tim, limit;
 450         unsigned n;
 451         int ret;
 452         u32 val;
 453
 454         if (addr >= high_memory) {
 455                 struct page *p1;
 456
 457                 if (((size_t)addr & PAGE_MASK) !=
 458                         ((size_t)(addr + len - 1) & PAGE_MASK))
 459                         goto out_copy;
 460                 p1 = vmalloc_to_page(addr);
 461                 if (!p1)
 462                         goto out_copy;
 463                 addr = page_address(p1) + ((size_t)addr & ~PAGE_MASK);
 464         }
 465
 466         sg_init_one(&sg, addr, len);
 467         n = dma_map_sg(info->dma->device->dev, &sg, 1, dir);
 468         if (n == 0) {
 469                 dev_err(&info->pdev->dev,
 470                         "Couldn't DMA map a %d byte buffer\n", len);
 471                 goto out_copy;
 472         }
 473
 474         tx = dmaengine_prep_slave_sg(info->dma, &sg, n,
 475                 is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM,
 476                 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 477         if (!tx)
 478                 goto out_copy_unmap;
 479
 480         tx->callback = omap_nand_dma_callback;
 481         tx->callback_param = &info->comp;
 482         dmaengine_submit(tx);
 483
 484         /*  configure and start prefetch transfer */
 485         ret = omap_prefetch_enable(info->gpmc_cs,
 486                 PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write, info);
 487         if (ret)
 488                 /* PFPW engine is busy, use cpu copy method */
 489                 goto out_copy_unmap;
 490
 491         init_completion(&info->comp);
 492         dma_async_issue_pending(info->dma);
 493
 494         /* setup and start DMA using dma_addr */
 495         wait_for_completion(&info->comp);
 496         tim = 0;
 497         limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
 498
 499         do {
 500                 cpu_relax();
 501                 val = readl(info->reg.gpmc_prefetch_status);
 502                 val = PREFETCH_STATUS_COUNT(val);
 503         } while (val && (tim++ < limit));
 504
 505         /* disable and stop the PFPW engine */
 506         omap_prefetch_reset(info->gpmc_cs, info);
 507
 508         dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
 509         return 0;
 510
 511 out_copy_unmap:
 512         dma_unmap_sg(info->dma->device->dev, &sg, 1, dir);
 513 out_copy:
 514         if (info->nand.options & NAND_BUSWIDTH_16)
 515                 is_write == 0 ? omap_read_buf16(mtd, (u_char *) addr, len)
 516                         : omap_write_buf16(mtd, (u_char *) addr, len);
 517         else
 518                 is_write == 0 ? omap_read_buf8(mtd, (u_char *) addr, len)
 519                         : omap_write_buf8(mtd, (u_char *) addr, len);
 520         return 0;
 521 }
 522
 523 /**
 524  * omap_read_buf_dma_pref - read data from NAND controller into buffer
 525  * @mtd: MTD device structure
 526  * @buf: buffer to store date
 527  * @len: number of bytes to read
 528  */
 529 static void omap_read_buf_dma_pref(struct mtd_info *mtd, u_char *buf, int len)
 530 {
 531         if (len <= mtd->oobsize)
 532                 omap_read_buf_pref(mtd, buf, len);
 533         else
 534                 /* start transfer in DMA mode */
 535                 omap_nand_dma_transfer(mtd, buf, len, 0x0);
 536 }
 537
 538 /**
 539  * omap_write_buf_dma_pref - write buffer to NAND controller
 540  * @mtd: MTD device structure
 541  * @buf: data buffer
 542  * @len: number of bytes to write
 543  */
 544 static void omap_write_buf_dma_pref(struct mtd_info *mtd,
 545                                         const u_char *buf, int len)
 546 {
 547         if (len <= mtd->oobsize)
 548                 omap_write_buf_pref(mtd, buf, len);
 549         else
 550                 /* start transfer in DMA mode */
 551                 omap_nand_dma_transfer(mtd, (u_char *) buf, len, 0x1);
 552 }
 553
 554 /*
 555  * omap_nand_irq - GPMC irq handler
 556  * @this_irq: gpmc irq number
 557  * @dev: omap_nand_info structure pointer is passed here
 558  */
 559 static irqreturn_t omap_nand_irq(int this_irq, void *dev)
 560 {
 561         struct omap_nand_info *info = (struct omap_nand_info *) dev;
 562         u32 bytes;
 563
 564         bytes = readl(info->reg.gpmc_prefetch_status);
 565         bytes = PREFETCH_STATUS_FIFO_CNT(bytes);
 566         bytes = bytes  & 0xFFFC; /* io in multiple of 4 bytes */
 567         if (info->iomode == OMAP_NAND_IO_WRITE) { /* checks for write io */
 568                 if (this_irq == info->gpmc_irq_count)
 569                         goto done;
 570
 571                 if (info->buf_len && (info->buf_len < bytes))
 572                         bytes = info->buf_len;
 573                 else if (!info->buf_len)
 574                         bytes = 0;
 575                 iowrite32_rep(info->nand.IO_ADDR_W,
 576                                                 (u32 *)info->buf, bytes >> 2);
 577                 info->buf = info->buf + bytes;
 578                 info->buf_len -= bytes;
 579
 580         } else {
 581                 ioread32_rep(info->nand.IO_ADDR_R,
 582                                                 (u32 *)info->buf, bytes >> 2);
 583                 info->buf = info->buf + bytes;
 584
 585                 if (this_irq == info->gpmc_irq_count)
 586                         goto done;
 587         }
 588
 589         return IRQ_HANDLED;
 590
 591 done:
 592         complete(&info->comp);
 593
 594         disable_irq_nosync(info->gpmc_irq_fifo);
 595         disable_irq_nosync(info->gpmc_irq_count);
 596
 597         return IRQ_HANDLED;
 598 }
 599
 600 /*
 601  * omap_read_buf_irq_pref - read data from NAND controller into buffer
 602  * @mtd: MTD device structure
 603  * @buf: buffer to store date
 604  * @len: number of bytes to read
 605  */
 606 static void omap_read_buf_irq_pref(struct mtd_info *mtd, u_char *buf, int len)
 607 {
 608         struct omap_nand_info *info = container_of(mtd,
 609                                                 struct omap_nand_info, mtd);
 610         int ret = 0;
 611
 612         if (len <= mtd->oobsize) {
 613                 omap_read_buf_pref(mtd, buf, len);
 614                 return;
 615         }
 616
 617         info->iomode = OMAP_NAND_IO_READ;
 618         info->buf = buf;
 619         init_completion(&info->comp);
 620
 621         /*  configure and start prefetch transfer */
 622         ret = omap_prefetch_enable(info->gpmc_cs,
 623                         PREFETCH_FIFOTHRESHOLD_MAX/2, 0x0, len, 0x0, info);
 624         if (ret)
 625                 /* PFPW engine is busy, use cpu copy method */
 626                 goto out_copy;
 627
 628         info->buf_len = len;
 629
 630         enable_irq(info->gpmc_irq_count);
 631         enable_irq(info->gpmc_irq_fifo);
 632
 633         /* waiting for read to complete */
 634         wait_for_completion(&info->comp);
 635
 636         /* disable and stop the PFPW engine */
 637         omap_prefetch_reset(info->gpmc_cs, info);
 638         return;
 639
 640 out_copy:
 641         if (info->nand.options & NAND_BUSWIDTH_16)
 642                 omap_read_buf16(mtd, buf, len);
 643         else
 644                 omap_read_buf8(mtd, buf, len);
 645 }
 646
 647 /*
 648  * omap_write_buf_irq_pref - write buffer to NAND controller
 649  * @mtd: MTD device structure
 650  * @buf: data buffer
 651  * @len: number of bytes to write
 652  */
 653 static void omap_write_buf_irq_pref(struct mtd_info *mtd,
 654                                         const u_char *buf, int len)
 655 {
 656         struct omap_nand_info *info = container_of(mtd,
 657                                                 struct omap_nand_info, mtd);
 658         int ret = 0;
 659         unsigned long tim, limit;
 660         u32 val;
 661
 662         if (len <= mtd->oobsize) {
 663                 omap_write_buf_pref(mtd, buf, len);
 664                 return;
 665         }
 666
 667         info->iomode = OMAP_NAND_IO_WRITE;
 668         info->buf = (u_char *) buf;
 669         init_completion(&info->comp);
 670
 671         /* configure and start prefetch transfer : size=24 */
 672         ret = omap_prefetch_enable(info->gpmc_cs,
 673                 (PREFETCH_FIFOTHRESHOLD_MAX * 3) / 8, 0x0, len, 0x1, info);
 674         if (ret)
 675                 /* PFPW engine is busy, use cpu copy method */
 676                 goto out_copy;
 677
 678         info->buf_len = len;
 679
 680         enable_irq(info->gpmc_irq_count);
 681         enable_irq(info->gpmc_irq_fifo);
 682
 683         /* waiting for write to complete */
 684         wait_for_completion(&info->comp);
 685
 686         /* wait for data to flushed-out before reset the prefetch */
 687         tim = 0;
 688         limit = (loops_per_jiffy *  msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS));
 689         do {
 690                 val = readl(info->reg.gpmc_prefetch_status);
 691                 val = PREFETCH_STATUS_COUNT(val);
 692                 cpu_relax();
 693         } while (val && (tim++ < limit));
 694
 695         /* disable and stop the PFPW engine */
 696         omap_prefetch_reset(info->gpmc_cs, info);
 697         return;
 698
 699 out_copy:
 700         if (info->nand.options & NAND_BUSWIDTH_16)
 701                 omap_write_buf16(mtd, buf, len);
 702         else
 703                 omap_write_buf8(mtd, buf, len);
 704 }
 705
 706 /**
 707  * gen_true_ecc - This function will generate true ECC value
 708  * @ecc_buf: buffer to store ecc code
 709  *
 710  * This generated true ECC value can be used when correcting
 711  * data read from NAND flash memory core
 712  */
 713 static void gen_true_ecc(u8 *ecc_buf)
 714 {
 715         u32 tmp = ecc_buf[0] | (ecc_buf[1] << 16) |
 716                 ((ecc_buf[2] & 0xF0) << 20) | ((ecc_buf[2] & 0x0F) << 8);
 717
 718         ecc_buf[0] = ~(P64o(tmp) | P64e(tmp) | P32o(tmp) | P32e(tmp) |
 719                         P16o(tmp) | P16e(tmp) | P8o(tmp) | P8e(tmp));
 720         ecc_buf[1] = ~(P1024o(tmp) | P1024e(tmp) | P512o(tmp) | P512e(tmp) |
 721                         P256o(tmp) | P256e(tmp) | P128o(tmp) | P128e(tmp));
 722         ecc_buf[2] = ~(P4o(tmp) | P4e(tmp) | P2o(tmp) | P2e(tmp) | P1o(tmp) |
 723                         P1e(tmp) | P2048o(tmp) | P2048e(tmp));
 724 }
 725
 726 /**
 727  * omap_compare_ecc - Detect (2 bits) and correct (1 bit) error in data
 728  * @ecc_data1:  ecc code from nand spare area
 729  * @ecc_data2:  ecc code from hardware register obtained from hardware ecc
 730  * @page_data:  page data
 731  *
 732  * This function compares two ECC's and indicates if there is an error.
 733  * If the error can be corrected it will be corrected to the buffer.
 734  * If there is no error, %0 is returned. If there is an error but it
 735  * was corrected, %1 is returned. Otherwise, %-1 is returned.
 736  */
 737 static int omap_compare_ecc(u8 *ecc_data1,      /* read from NAND memory */
 738                             u8 *ecc_data2,      /* read from register */
 739                             u8 *page_data)
 740 {
 741         uint    i;
 742         u8      tmp0_bit[8], tmp1_bit[8], tmp2_bit[8];
 743         u8      comp0_bit[8], comp1_bit[8], comp2_bit[8];
 744         u8      ecc_bit[24];
 745         u8      ecc_sum = 0;
 746         u8      find_bit = 0;
 747         uint    find_byte = 0;
 748         int     isEccFF;
 749
 750         isEccFF = ((*(u32 *)ecc_data1 & 0xFFFFFF) == 0xFFFFFF);
 751
 752         gen_true_ecc(ecc_data1);
 753         gen_true_ecc(ecc_data2);
 754
 755         for (i = 0; i <= 2; i++) {
 756                 *(ecc_data1 + i) = ~(*(ecc_data1 + i));
 757                 *(ecc_data2 + i) = ~(*(ecc_data2 + i));
 758         }
 759
 760         for (i = 0; i < 8; i++) {
 761                 tmp0_bit[i]     = *ecc_data1 % 2;
 762                 *ecc_data1      = *ecc_data1 / 2;
 763         }
 764
 765         for (i = 0; i < 8; i++) {
 766                 tmp1_bit[i]      = *(ecc_data1 + 1) % 2;
 767                 *(ecc_data1 + 1) = *(ecc_data1 + 1) / 2;
 768         }
 769
 770         for (i = 0; i < 8; i++) {
 771                 tmp2_bit[i]      = *(ecc_data1 + 2) % 2;
 772                 *(ecc_data1 + 2) = *(ecc_data1 + 2) / 2;
 773         }
 774
 775         for (i = 0; i < 8; i++) {
 776                 comp0_bit[i]     = *ecc_data2 % 2;
 777                 *ecc_data2       = *ecc_data2 / 2;
 778         }
 779
 780         for (i = 0; i < 8; i++) {
 781                 comp1_bit[i]     = *(ecc_data2 + 1) % 2;
 782                 *(ecc_data2 + 1) = *(ecc_data2 + 1) / 2;
 783         }
 784
 785         for (i = 0; i < 8; i++) {
 786                 comp2_bit[i]     = *(ecc_data2 + 2) % 2;
 787                 *(ecc_data2 + 2) = *(ecc_data2 + 2) / 2;
 788         }
 789
 790         for (i = 0; i < 6; i++)
 791                 ecc_bit[i] = tmp2_bit[i + 2] ^ comp2_bit[i + 2];
 792
 793         for (i = 0; i < 8; i++)
 794                 ecc_bit[i + 6] = tmp0_bit[i] ^ comp0_bit[i];
 795
 796         for (i = 0; i < 8; i++)
 797                 ecc_bit[i + 14] = tmp1_bit[i] ^ comp1_bit[i];
 798
 799         ecc_bit[22] = tmp2_bit[0] ^ comp2_bit[0];
 800         ecc_bit[23] = tmp2_bit[1] ^ comp2_bit[1];
 801
 802         for (i = 0; i < 24; i++)
 803                 ecc_sum += ecc_bit[i];
 804
 805         switch (ecc_sum) {
 806         case 0:
 807                 /* Not reached because this function is not called if
 808                  *  ECC values are equal
 809                  */
 810                 return 0;
 811
 812         case 1:
 813                 /* Uncorrectable error */
 814                 pr_debug("ECC UNCORRECTED_ERROR 1\n");
 815                 return -1;
 816
 817         case 11:
 818                 /* UN-Correctable error */
 819                 pr_debug("ECC UNCORRECTED_ERROR B\n");
 820                 return -1;
 821
 822         case 12:
 823                 /* Correctable error */
 824                 find_byte = (ecc_bit[23] << 8) +
 825                             (ecc_bit[21] << 7) +
 826                             (ecc_bit[19] << 6) +
 827                             (ecc_bit[17] << 5) +
 828                             (ecc_bit[15] << 4) +
 829                             (ecc_bit[13] << 3) +
 830                             (ecc_bit[11] << 2) +
 831                             (ecc_bit[9]  << 1) +
 832                             ecc_bit[7];
 833
 834                 find_bit = (ecc_bit[5] << 2) + (ecc_bit[3] << 1) + ecc_bit[1];
 835
 836                 pr_debug("Correcting single bit ECC error at offset: "
 837                                 "%d, bit: %d\n", find_byte, find_bit);
 838
 839                 page_data[find_byte] ^= (1 << find_bit);
 840
 841                 return 1;
 842         default:
 843                 if (isEccFF) {
 844                         if (ecc_data2[0] == 0 &&
 845                             ecc_data2[1] == 0 &&
 846                             ecc_data2[2] == 0)
 847                                 return 0;
 848                 }
 849                 pr_debug("UNCORRECTED_ERROR default\n");
 850                 return -1;
 851         }
 852 }
 853
 854 /**
 855  * omap_correct_data - Compares the ECC read with HW generated ECC
 856  * @mtd: MTD device structure
 857  * @dat: page data
 858  * @read_ecc: ecc read from nand flash
 859  * @calc_ecc: ecc read from HW ECC registers
 860  *
 861  * Compares the ecc read from nand spare area with ECC registers values
 862  * and if ECC's mismatched, it will call 'omap_compare_ecc' for error
 863  * detection and correction. If there are no errors, %0 is returned. If
 864  * there were errors and all of the errors were corrected, the number of
 865  * corrected errors is returned. If uncorrectable errors exist, %-1 is
 866  * returned.
 867  */
 868 static int omap_correct_data(struct mtd_info *mtd, u_char *dat,
 869                                 u_char *read_ecc, u_char *calc_ecc)
 870 {
 871         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 872                                                         mtd);
 873         int blockCnt = 0, i = 0, ret = 0;
 874         int stat = 0;
 875
 876         /* Ex NAND_ECC_HW12_2048 */
 877         if ((info->nand.ecc.mode == NAND_ECC_HW) &&
 878                         (info->nand.ecc.size  == 2048))
 879                 blockCnt = 4;
 880         else
 881                 blockCnt = 1;
 882
 883         for (i = 0; i < blockCnt; i++) {
 884                 if (memcmp(read_ecc, calc_ecc, 3) != 0) {
 885                         ret = omap_compare_ecc(read_ecc, calc_ecc, dat);
 886                         if (ret < 0)
 887                                 return ret;
 888                         /* keep track of the number of corrected errors */
 889                         stat += ret;
 890                 }
 891                 read_ecc += 3;
 892                 calc_ecc += 3;
 893                 dat      += 512;
 894         }
 895         return stat;
 896 }
 897
 898 /**
 899  * omap_calcuate_ecc - Generate non-inverted ECC bytes.
 900  * @mtd: MTD device structure
 901  * @dat: The pointer to data on which ecc is computed
 902  * @ecc_code: The ecc_code buffer
 903  *
 904  * Using noninverted ECC can be considered ugly since writing a blank
 905  * page ie. padding will clear the ECC bytes. This is no problem as long
 906  * nobody is trying to write data on the seemingly unused page. Reading
 907  * an erased page will produce an ECC mismatch between generated and read
 908  * ECC bytes that has to be dealt with separately.
 909  */
 910 static int omap_calculate_ecc(struct mtd_info *mtd, const u_char *dat,
 911                                 u_char *ecc_code)
 912 {
 913         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 914                                                         mtd);
 915         u32 val;
 916
 917         val = readl(info->reg.gpmc_ecc_config);
 918         if (((val >> ECC_CONFIG_CS_SHIFT)  & ~CS_MASK) != info->gpmc_cs)
 919                 return -EINVAL;
 920
 921         /* read ecc result */
 922         val = readl(info->reg.gpmc_ecc1_result);
 923         *ecc_code++ = val;          /* P128e, ..., P1e */
 924         *ecc_code++ = val >> 16;    /* P128o, ..., P1o */
 925         /* P2048o, P1024o, P512o, P256o, P2048e, P1024e, P512e, P256e */
 926         *ecc_code++ = ((val >> 8) & 0x0f) | ((val >> 20) & 0xf0);
 927
 928         return 0;
 929 }
 930
 931 /**
 932  * omap_enable_hwecc - This function enables the hardware ecc functionality
 933  * @mtd: MTD device structure
 934  * @mode: Read/Write mode
 935  */
 936 static void omap_enable_hwecc(struct mtd_info *mtd, int mode)
 937 {
 938         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 939                                                         mtd);
 940         struct nand_chip *chip = mtd->priv;
 941         unsigned int dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
 942         u32 val;
 943
 944         /* clear ecc and enable bits */
 945         val = ECCCLEAR | ECC1;
 946         writel(val, info->reg.gpmc_ecc_control);
 947
 948         /* program ecc and result sizes */
 949         val = ((((info->nand.ecc.size >> 1) - 1) << ECCSIZE1_SHIFT) |
 950                          ECC1RESULTSIZE);
 951         writel(val, info->reg.gpmc_ecc_size_config);
 952
 953         switch (mode) {
 954         case NAND_ECC_READ:
 955         case NAND_ECC_WRITE:
 956                 writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
 957                 break;
 958         case NAND_ECC_READSYN:
 959                 writel(ECCCLEAR, info->reg.gpmc_ecc_control);
 960                 break;
 961         default:
 962                 dev_info(&info->pdev->dev,
 963                         "error: unrecognized Mode[%d]!\n", mode);
 964                 break;
 965         }
 966
 967         /* (ECC 16 or 8 bit col) | ( CS  )  | ECC Enable */
 968         val = (dev_width << 7) | (info->gpmc_cs << 1) | (0x1);
 969         writel(val, info->reg.gpmc_ecc_config);
 970 }
 971
 972 /**
 973  * omap_wait - wait until the command is done
 974  * @mtd: MTD device structure
 975  * @chip: NAND Chip structure
 976  *
 977  * Wait function is called during Program and erase operations and
 978  * the way it is called from MTD layer, we should wait till the NAND
 979  * chip is ready after the programming/erase operation has completed.
 980  *
 981  * Erase can take up to 400ms and program up to 20ms according to
 982  * general NAND and SmartMedia specs
 983  */
 984 static int omap_wait(struct mtd_info *mtd, struct nand_chip *chip)
 985 {
 986         struct nand_chip *this = mtd->priv;
 987         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
 988                                                         mtd);
 989         unsigned long timeo = jiffies;
 990         int status, state = this->state;
 991
 992         if (state == FL_ERASING)
 993                 timeo += (HZ * 400) / 1000;
 994         else
 995                 timeo += (HZ * 20) / 1000;
 996
 997         writeb(NAND_CMD_STATUS & 0xFF, info->reg.gpmc_nand_command);
 998         while (time_before(jiffies, timeo)) {
 999                 status = readb(info->reg.gpmc_nand_data);
1000                 if (status & NAND_STATUS_READY)
1001                         break;
1002                 cond_resched();
1003         }
1004
1005         status = readb(info->reg.gpmc_nand_data);
1006         return status;
1007 }
1008
1009 /**
1010  * omap_dev_ready - calls the platform specific dev_ready function
1011  * @mtd: MTD device structure
1012  */
1013 static int omap_dev_ready(struct mtd_info *mtd)
1014 {
1015         unsigned int val = 0;
1016         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1017                                                         mtd);
1018
1019         val = readl(info->reg.gpmc_status);
1020
1021         if ((val & 0x100) == 0x100) {
1022                 return 1;
1023         } else {
1024                 return 0;
1025         }
1026 }
1027
1028 #ifdef CONFIG_MTD_NAND_OMAP_BCH
1029
1030 /**
1031  * omap3_enable_hwecc_bch - Program OMAP3 GPMC to perform BCH ECC correction
1032  * @mtd: MTD device structure
1033  * @mode: Read/Write mode
1034  */
1035 static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
1036 {
1037         int nerrors;
1038         unsigned int dev_width, nsectors;
1039         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1040                                                    mtd);
1041         struct nand_chip *chip = mtd->priv;
1042         u32 val;
1043
1044         nerrors = (info->nand.ecc.bytes == 13) ? 8 : 4;
1045         dev_width = (chip->options & NAND_BUSWIDTH_16) ? 1 : 0;
1046         nsectors = 1;
1047         /*
1048          * Program GPMC to perform correction on one 512-byte sector at a time.
1049          * Using 4 sectors at a time (i.e. ecc.size = 2048) is also possible and
1050          * gives a slight (5%) performance gain (but requires additional code).
1051          */
1052
1053         writel(ECC1, info->reg.gpmc_ecc_control);
1054
1055         /*
1056          * When using BCH, sector size is hardcoded to 512 bytes.
1057          * Here we are using wrapping mode 6 both for reading and writing, with:
1058          *  size0 = 0  (no additional protected byte in spare area)
1059          *  size1 = 32 (skip 32 nibbles = 16 bytes per sector in spare area)
1060          */
1061         val = (32 << ECCSIZE1_SHIFT) | (0 << ECCSIZE0_SHIFT);
1062         writel(val, info->reg.gpmc_ecc_size_config);
1063
1064         /* BCH configuration */
1065         val = ((1                        << 16) | /* enable BCH */
1066                (((nerrors == 8) ? 1 : 0) << 12) | /* 8 or 4 bits */
1067                (0x06                     <<  8) | /* wrap mode = 6 */
1068                (dev_width                <<  7) | /* bus width */
1069                (((nsectors-1) & 0x7)     <<  4) | /* number of sectors */
1070                (info->gpmc_cs            <<  1) | /* ECC CS */
1071                (0x1));                            /* enable ECC */
1072
1073         writel(val, info->reg.gpmc_ecc_config);
1074
1075         /* clear ecc and enable bits */
1076         writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
1077 }
1078
1079 /**
1080  * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes
1081  * @mtd: MTD device structure
1082  * @dat: The pointer to data on which ecc is computed
1083  * @ecc_code: The ecc_code buffer
1084  */
1085 static int omap3_calculate_ecc_bch4(struct mtd_info *mtd, const u_char *dat,
1086                                     u_char *ecc_code)
1087 {
1088         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1089                                                    mtd);
1090         unsigned long nsectors, val1, val2;
1091         int i;
1092
1093         nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
1094
1095         for (i = 0; i < nsectors; i++) {
1096
1097                 /* Read hw-computed remainder */
1098                 val1 = readl(info->reg.gpmc_bch_result0[i]);
1099                 val2 = readl(info->reg.gpmc_bch_result1[i]);
1100
1101                 /*
1102                  * Add constant polynomial to remainder, in order to get an ecc
1103                  * sequence of 0xFFs for a buffer filled with 0xFFs; and
1104                  * left-justify the resulting polynomial.
1105                  */
1106                 *ecc_code++ = 0x28 ^ ((val2 >> 12) & 0xFF);
1107                 *ecc_code++ = 0x13 ^ ((val2 >>  4) & 0xFF);
1108                 *ecc_code++ = 0xcc ^ (((val2 & 0xF) << 4)|((val1 >> 28) & 0xF));
1109                 *ecc_code++ = 0x39 ^ ((val1 >> 20) & 0xFF);
1110                 *ecc_code++ = 0x96 ^ ((val1 >> 12) & 0xFF);
1111                 *ecc_code++ = 0xac ^ ((val1 >> 4) & 0xFF);
1112                 *ecc_code++ = 0x7f ^ ((val1 & 0xF) << 4);
1113         }
1114
1115         return 0;
1116 }
1117
1118 /**
1119  * omap3_calculate_ecc_bch8 - Generate 13 bytes of ECC bytes
1120  * @mtd: MTD device structure
1121  * @dat: The pointer to data on which ecc is computed
1122  * @ecc_code: The ecc_code buffer
1123  */
1124 static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
1125                                     u_char *ecc_code)
1126 {
1127         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1128                                                    mtd);
1129         unsigned long nsectors, val1, val2, val3, val4;
1130         int i;
1131
1132         nsectors = ((readl(info->reg.gpmc_ecc_config) >> 4) & 0x7) + 1;
1133
1134         for (i = 0; i < nsectors; i++) {
1135
1136                 /* Read hw-computed remainder */
1137                 val1 = readl(info->reg.gpmc_bch_result0[i]);
1138                 val2 = readl(info->reg.gpmc_bch_result1[i]);
1139                 val3 = readl(info->reg.gpmc_bch_result2[i]);
1140                 val4 = readl(info->reg.gpmc_bch_result3[i]);
1141
1142                 /*
1143                  * Add constant polynomial to remainder, in order to get an ecc
1144                  * sequence of 0xFFs for a buffer filled with 0xFFs.
1145                  */
1146                 *ecc_code++ = 0xef ^ (val4 & 0xFF);
1147                 *ecc_code++ = 0x51 ^ ((val3 >> 24) & 0xFF);
1148                 *ecc_code++ = 0x2e ^ ((val3 >> 16) & 0xFF);
1149                 *ecc_code++ = 0x09 ^ ((val3 >> 8) & 0xFF);
1150                 *ecc_code++ = 0xed ^ (val3 & 0xFF);
1151                 *ecc_code++ = 0x93 ^ ((val2 >> 24) & 0xFF);
1152                 *ecc_code++ = 0x9a ^ ((val2 >> 16) & 0xFF);
1153                 *ecc_code++ = 0xc2 ^ ((val2 >> 8) & 0xFF);
1154                 *ecc_code++ = 0x97 ^ (val2 & 0xFF);
1155                 *ecc_code++ = 0x79 ^ ((val1 >> 24) & 0xFF);
1156                 *ecc_code++ = 0xe5 ^ ((val1 >> 16) & 0xFF);
1157                 *ecc_code++ = 0x24 ^ ((val1 >> 8) & 0xFF);
1158                 *ecc_code++ = 0xb5 ^ (val1 & 0xFF);
1159         }
1160
1161         return 0;
1162 }
1163
1164 /**
1165  * omap3_correct_data_bch - Decode received data and correct errors
1166  * @mtd: MTD device structure
1167  * @data: page data
1168  * @read_ecc: ecc read from nand flash
1169  * @calc_ecc: ecc read from HW ECC registers
1170  */
1171 static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data,
1172                                   u_char *read_ecc, u_char *calc_ecc)
1173 {
1174         int i, count;
1175         /* cannot correct more than 8 errors */
1176         unsigned int errloc[8];
1177         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1178                                                    mtd);
1179
1180         count = decode_bch(info->bch, NULL, 512, read_ecc, calc_ecc, NULL,
1181                            errloc);
1182         if (count > 0) {
1183                 /* correct errors */
1184                 for (i = 0; i < count; i++) {
1185                         /* correct data only, not ecc bytes */
1186                         if (errloc[i] < 8*512)
1187                                 data[errloc[i]/8] ^= 1 << (errloc[i] & 7);
1188                         pr_debug("corrected bitflip %u\n", errloc[i]);
1189                 }
1190         } else if (count < 0) {
1191                 pr_err("ecc unrecoverable error\n");
1192         }
1193         return count;
1194 }
1195
1196 /**
1197  * omap3_free_bch - Release BCH ecc resources
1198  * @mtd: MTD device structure
1199  */
1200 static void omap3_free_bch(struct mtd_info *mtd)
1201 {
1202         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1203                                                    mtd);
1204         if (info->bch) {
1205                 free_bch(info->bch);
1206                 info->bch = NULL;
1207         }
1208 }
1209
1210 /**
1211  * omap3_init_bch - Initialize BCH ECC
1212  * @mtd: MTD device structure
1213  * @ecc_opt: OMAP ECC mode (OMAP_ECC_BCH4_CODE_HW or OMAP_ECC_BCH8_CODE_HW)
1214  */
1215 static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
1216 {
1217         int max_errors;
1218         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1219                                                    mtd);
1220 #ifdef CONFIG_MTD_NAND_OMAP_BCH8
1221         const int hw_errors = 8;
1222 #else
1223         const int hw_errors = 4;
1224 #endif
1225         info->bch = NULL;
1226
1227         max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ? 8 : 4;
1228         if (max_errors != hw_errors) {
1229                 pr_err("cannot configure %d-bit BCH ecc, only %d-bit supported",
1230                        max_errors, hw_errors);
1231                 goto fail;
1232         }
1233
1234         /* software bch library is only used to detect and locate errors */
1235         info->bch = init_bch(13, max_errors, 0x201b /* hw polynomial */);
1236         if (!info->bch)
1237                 goto fail;
1238
1239         info->nand.ecc.size    = 512;
1240         info->nand.ecc.hwctl   = omap3_enable_hwecc_bch;
1241         info->nand.ecc.correct = omap3_correct_data_bch;
1242         info->nand.ecc.mode    = NAND_ECC_HW;
1243
1244         /*
1245          * The number of corrected errors in an ecc block that will trigger
1246          * block scrubbing defaults to the ecc strength (4 or 8).
1247          * Set mtd->bitflip_threshold here to define a custom threshold.
1248          */
1249
1250         if (max_errors == 8) {
1251                 info->nand.ecc.strength  = 8;
1252                 info->nand.ecc.bytes     = 13;
1253                 info->nand.ecc.calculate = omap3_calculate_ecc_bch8;
1254         } else {
1255                 info->nand.ecc.strength  = 4;
1256                 info->nand.ecc.bytes     = 7;
1257                 info->nand.ecc.calculate = omap3_calculate_ecc_bch4;
1258         }
1259
1260         pr_info("enabling NAND BCH ecc with %d-bit correction\n", max_errors);
1261         return 0;
1262 fail:
1263         omap3_free_bch(mtd);
1264         return -1;
1265 }
1266
1267 /**
1268  * omap3_init_bch_tail - Build an oob layout for BCH ECC correction.
1269  * @mtd: MTD device structure
1270  */
1271 static int omap3_init_bch_tail(struct mtd_info *mtd)
1272 {
1273         int i, steps;
1274         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1275                                                    mtd);
1276         struct nand_ecclayout *layout = &info->ecclayout;
1277
1278         /* build oob layout */
1279         steps = mtd->writesize/info->nand.ecc.size;
1280         layout->eccbytes = steps*info->nand.ecc.bytes;
1281
1282         /* do not bother creating special oob layouts for small page devices */
1283         if (mtd->oobsize < 64) {
1284                 pr_err("BCH ecc is not supported on small page devices\n");
1285                 goto fail;
1286         }
1287
1288         /* reserve 2 bytes for bad block marker */
1289         if (layout->eccbytes+2 > mtd->oobsize) {
1290                 pr_err("no oob layout available for oobsize %d eccbytes %u\n",
1291                        mtd->oobsize, layout->eccbytes);
1292                 goto fail;
1293         }
1294
1295         /* put ecc bytes at oob tail */
1296         for (i = 0; i < layout->eccbytes; i++)
1297                 layout->eccpos[i] = mtd->oobsize-layout->eccbytes+i;
1298
1299         layout->oobfree[0].offset = 2;
1300         layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
1301         info->nand.ecc.layout = layout;
1302
1303         if (!(info->nand.options & NAND_BUSWIDTH_16))
1304                 info->nand.badblock_pattern = &bb_descrip_flashbased;
1305         return 0;
1306 fail:
1307         omap3_free_bch(mtd);
1308         return -1;
1309 }
1310
1311 #else
1312 static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
1313 {
1314         pr_err("CONFIG_MTD_NAND_OMAP_BCH is not enabled\n");
1315         return -1;
1316 }
1317 static int omap3_init_bch_tail(struct mtd_info *mtd)
1318 {
1319         return -1;
1320 }
1321 static void omap3_free_bch(struct mtd_info *mtd)
1322 {
1323 }
1324 #endif /* CONFIG_MTD_NAND_OMAP_BCH */
1325
1326 static int __devinit omap_nand_probe(struct platform_device *pdev)
1327 {
1328         struct omap_nand_info           *info;
1329         struct omap_nand_platform_data  *pdata;
1330         int                             err;
1331         int                             i, offset;
1332         dma_cap_mask_t mask;
1333         unsigned sig;
1334         struct resource                 *res;
1335
1336         pdata = pdev->dev.platform_data;
1337         if (pdata == NULL) {
1338                 dev_err(&pdev->dev, "platform data missing\n");
1339                 return -ENODEV;
1340         }
1341
1342         info = kzalloc(sizeof(struct omap_nand_info), GFP_KERNEL);
1343         if (!info)
1344                 return -ENOMEM;
1345
1346         platform_set_drvdata(pdev, info);
1347
1348         spin_lock_init(&info->controller.lock);
1349         init_waitqueue_head(&info->controller.wq);
1350
1351         info->pdev = pdev;
1352
1353         info->gpmc_cs           = pdata->cs;
1354         info->reg               = pdata->reg;
1355
1356         info->mtd.priv          = &info->nand;
1357         info->mtd.name          = dev_name(&pdev->dev);
1358         info->mtd.owner         = THIS_MODULE;
1359
1360         info->nand.options      = pdata->devsize;
1361         info->nand.options      |= NAND_SKIP_BBTSCAN;
1362
1363         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1364         if (res == NULL) {
1365                 err = -EINVAL;
1366                 dev_err(&pdev->dev, "error getting memory resource\n");
1367                 goto out_free_info;
1368         }
1369
1370         info->phys_base = res->start;
1371         info->mem_size = resource_size(res);
1372
1373         if (!request_mem_region(info->phys_base, info->mem_size,
1374                                 pdev->dev.driver->name)) {
1375                 err = -EBUSY;
1376                 goto out_free_info;
1377         }
1378
1379         info->nand.IO_ADDR_R = ioremap(info->phys_base, info->mem_size);
1380         if (!info->nand.IO_ADDR_R) {
1381                 err = -ENOMEM;
1382                 goto out_release_mem_region;
1383         }
1384
1385         info->nand.controller = &info->controller;
1386
1387         info->nand.IO_ADDR_W = info->nand.IO_ADDR_R;
1388         info->nand.cmd_ctrl  = omap_hwcontrol;
1389
1390         /*
1391          * If RDY/BSY line is connected to OMAP then use the omap ready
1392          * function and the generic nand_wait function which reads the status
1393          * register after monitoring the RDY/BSY line. Otherwise use a standard
1394          * chip delay which is slightly more than tR (AC Timing) of the NAND
1395          * device and read status register until you get a failure or success
1396          */
1397         if (pdata->dev_ready) {
1398                 info->nand.dev_ready = omap_dev_ready;
1399                 info->nand.chip_delay = 0;
1400         } else {
1401                 info->nand.waitfunc = omap_wait;
1402                 info->nand.chip_delay = 50;
1403         }
1404
1405         switch (pdata->xfer_type) {
1406         case NAND_OMAP_PREFETCH_POLLED:
1407                 info->nand.read_buf   = omap_read_buf_pref;
1408                 info->nand.write_buf  = omap_write_buf_pref;
1409                 break;
1410
1411         case NAND_OMAP_POLLED:
1412                 if (info->nand.options & NAND_BUSWIDTH_16) {
1413                         info->nand.read_buf   = omap_read_buf16;
1414                         info->nand.write_buf  = omap_write_buf16;
1415                 } else {
1416                         info->nand.read_buf   = omap_read_buf8;
1417                         info->nand.write_buf  = omap_write_buf8;
1418                 }
1419                 break;
1420
1421         case NAND_OMAP_PREFETCH_DMA:
1422                 dma_cap_zero(mask);
1423                 dma_cap_set(DMA_SLAVE, mask);
1424                 sig = OMAP24XX_DMA_GPMC;
1425                 info->dma = dma_request_channel(mask, omap_dma_filter_fn, &sig);
1426                 if (!info->dma) {
1427                         dev_err(&pdev->dev, "DMA engine request failed\n");
1428                         err = -ENXIO;
1429                         goto out_release_mem_region;
1430                 } else {
1431                         struct dma_slave_config cfg;
1432
1433                         memset(&cfg, 0, sizeof(cfg));
1434                         cfg.src_addr = info->phys_base;
1435                         cfg.dst_addr = info->phys_base;
1436                         cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1437                         cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1438                         cfg.src_maxburst = 16;
1439                         cfg.dst_maxburst = 16;
1440                         err = dmaengine_slave_config(info->dma, &cfg);
1441                         if (err) {
1442                                 dev_err(&pdev->dev, "DMA engine slave config failed: %d\n",
1443                                         err);
1444                                 goto out_release_mem_region;
1445                         }
1446                         info->nand.read_buf   = omap_read_buf_dma_pref;
1447                         info->nand.write_buf  = omap_write_buf_dma_pref;
1448                 }
1449                 break;
1450
1451         case NAND_OMAP_PREFETCH_IRQ:
1452                 info->gpmc_irq_fifo = platform_get_irq(pdev, 0);
1453                 if (info->gpmc_irq_fifo <= 0) {
1454                         dev_err(&pdev->dev, "error getting fifo irq\n");
1455                         err = -ENODEV;
1456                         goto out_release_mem_region;
1457                 }
1458                 err = request_irq(info->gpmc_irq_fifo,  omap_nand_irq,
1459                                         IRQF_SHARED, "gpmc-nand-fifo", info);
1460                 if (err) {
1461                         dev_err(&pdev->dev, "requesting irq(%d) error:%d",
1462                                                 info->gpmc_irq_fifo, err);
1463                         info->gpmc_irq_fifo = 0;
1464                         goto out_release_mem_region;
1465                 }
1466
1467                 info->gpmc_irq_count = platform_get_irq(pdev, 1);
1468                 if (info->gpmc_irq_count <= 0) {
1469                         dev_err(&pdev->dev, "error getting count irq\n");
1470                         err = -ENODEV;
1471                         goto out_release_mem_region;
1472                 }
1473                 err = request_irq(info->gpmc_irq_count, omap_nand_irq,
1474                                         IRQF_SHARED, "gpmc-nand-count", info);
1475                 if (err) {
1476                         dev_err(&pdev->dev, "requesting irq(%d) error:%d",
1477                                                 info->gpmc_irq_count, err);
1478                         info->gpmc_irq_count = 0;
1479                         goto out_release_mem_region;
1480                 }
1481
1482                 info->nand.read_buf  = omap_read_buf_irq_pref;
1483                 info->nand.write_buf = omap_write_buf_irq_pref;
1484
1485                 break;
1486
1487         default:
1488                 dev_err(&pdev->dev,
1489                         "xfer_type(%d) not supported!\n", pdata->xfer_type);
1490                 err = -EINVAL;
1491                 goto out_release_mem_region;
1492         }
1493
1494         /* select the ecc type */
1495         if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_DEFAULT)
1496                 info->nand.ecc.mode = NAND_ECC_SOFT;
1497         else if ((pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW) ||
1498                 (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE)) {
1499                 info->nand.ecc.bytes            = 3;
1500                 info->nand.ecc.size             = 512;
1501                 info->nand.ecc.strength         = 1;
1502                 info->nand.ecc.calculate        = omap_calculate_ecc;
1503                 info->nand.ecc.hwctl            = omap_enable_hwecc;
1504                 info->nand.ecc.correct          = omap_correct_data;
1505                 info->nand.ecc.mode             = NAND_ECC_HW;
1506         } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
1507                    (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
1508                 err = omap3_init_bch(&info->mtd, pdata->ecc_opt);
1509                 if (err) {
1510                         err = -EINVAL;
1511                         goto out_release_mem_region;
1512                 }
1513         }
1514
1515         /* DIP switches on some boards change between 8 and 16 bit
1516          * bus widths for flash.  Try the other width if the first try fails.
1517          */
1518         if (nand_scan_ident(&info->mtd, 1, NULL)) {
1519                 info->nand.options ^= NAND_BUSWIDTH_16;
1520                 if (nand_scan_ident(&info->mtd, 1, NULL)) {
1521                         err = -ENXIO;
1522                         goto out_release_mem_region;
1523                 }
1524         }
1525
1526         /* rom code layout */
1527         if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE) {
1528
1529                 if (info->nand.options & NAND_BUSWIDTH_16)
1530                         offset = 2;
1531                 else {
1532                         offset = 1;
1533                         info->nand.badblock_pattern = &bb_descrip_flashbased;
1534                 }
1535                 omap_oobinfo.eccbytes = 3 * (info->mtd.oobsize/16);
1536                 for (i = 0; i < omap_oobinfo.eccbytes; i++)
1537                         omap_oobinfo.eccpos[i] = i+offset;
1538
1539                 omap_oobinfo.oobfree->offset = offset + omap_oobinfo.eccbytes;
1540                 omap_oobinfo.oobfree->length = info->mtd.oobsize -
1541                                         (offset + omap_oobinfo.eccbytes);
1542
1543                 info->nand.ecc.layout = &omap_oobinfo;
1544         } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
1545                    (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
1546                 /* build OOB layout for BCH ECC correction */
1547                 err = omap3_init_bch_tail(&info->mtd);
1548                 if (err) {
1549                         err = -EINVAL;
1550                         goto out_release_mem_region;
1551                 }
1552         }
1553
1554         /* second phase scan */
1555         if (nand_scan_tail(&info->mtd)) {
1556                 err = -ENXIO;
1557                 goto out_release_mem_region;
1558         }
1559
1560         mtd_device_parse_register(&info->mtd, NULL, NULL, pdata->parts,
1561                                   pdata->nr_parts);
1562
1563         platform_set_drvdata(pdev, &info->mtd);
1564
1565         return 0;
1566
1567 out_release_mem_region:
1568         if (info->dma)
1569                 dma_release_channel(info->dma);
1570         if (info->gpmc_irq_count > 0)
1571                 free_irq(info->gpmc_irq_count, info);
1572         if (info->gpmc_irq_fifo > 0)
1573                 free_irq(info->gpmc_irq_fifo, info);
1574         release_mem_region(info->phys_base, info->mem_size);
1575 out_free_info:
1576         kfree(info);
1577
1578         return err;
1579 }
1580
1581 static int omap_nand_remove(struct platform_device *pdev)
1582 {
1583         struct mtd_info *mtd = platform_get_drvdata(pdev);
1584         struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
1585                                                         mtd);
1586         omap3_free_bch(&info->mtd);
1587
1588         platform_set_drvdata(pdev, NULL);
1589         if (info->dma)
1590                 dma_release_channel(info->dma);
1591
1592         if (info->gpmc_irq_count > 0)
1593                 free_irq(info->gpmc_irq_count, info);
1594         if (info->gpmc_irq_fifo > 0)
1595                 free_irq(info->gpmc_irq_fifo, info);
1596
1597         /* Release NAND device, its internal structures and partitions */
1598         nand_release(&info->mtd);
1599         iounmap(info->nand.IO_ADDR_R);
1600         release_mem_region(info->phys_base, info->mem_size);
1601         kfree(info);
1602         return 0;
1603 }
1604
1605 static struct platform_driver omap_nand_driver = {
1606         .probe          = omap_nand_probe,
1607         .remove         = omap_nand_remove,
1608         .driver         = {
1609                 .name   = DRIVER_NAME,
1610                 .owner  = THIS_MODULE,
1611         },
1612 };
1613
1614 module_platform_driver(omap_nand_driver);
1615
1616 MODULE_ALIAS("platform:" DRIVER_NAME);
1617 MODULE_LICENSE("GPL");
1618 MODULE_DESCRIPTION("Glue layer for NAND flash on TI OMAP boards");