drivers/mtd/nand/bcm_umi_bch.c

   1 /*****************************************************************************
   2 * Copyright 2004 - 2009 Broadcom Corporation.  All rights reserved.
   3 *
   4 * Unless you and Broadcom execute a separate written software license
   5 * agreement governing use of this software, this software is licensed to you
   6 * under the terms of the GNU General Public License version 2, available at
   7 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
   8 *
   9 * Notwithstanding the above, under no circumstances may you combine this
  10 * software in any way with any other Broadcom software provided under a
  11 * license other than the GPL, without Broadcom's express prior written
  12 * consent.
  13 *****************************************************************************/
  14
  15 /* ---- Include Files ---------------------------------------------------- */
  16 #include "nand_bcm_umi.h"
  17
  18 /* ---- External Variable Declarations ----------------------------------- */
  19 /* ---- External Function Prototypes ------------------------------------- */
  20 /* ---- Public Variables ------------------------------------------------- */
  21 /* ---- Private Constants and Types -------------------------------------- */
  22
  23 /* ---- Private Function Prototypes -------------------------------------- */
  24 static int bcm_umi_bch_read_page_hwecc(struct mtd_info *mtd,
  25         struct nand_chip *chip, uint8_t *buf, int oob_required, int page);
  26 static void bcm_umi_bch_write_page_hwecc(struct mtd_info *mtd,
  27         struct nand_chip *chip, const uint8_t *buf, int oob_required);
  28
  29 /* ---- Private Variables ------------------------------------------------ */
  30
  31 /*
  32 ** nand_hw_eccoob
  33 ** New oob placement block for use with hardware ecc generation.
  34 */
  35 static struct nand_ecclayout nand_hw_eccoob_512 = {
  36         /* Reserve 5 for BI indicator */
  37         .oobfree = {
  38 #if (NAND_ECC_NUM_BYTES > 3)
  39                     {.offset = 0, .length = 2}
  40 #else
  41                     {.offset = 0, .length = 5},
  42                     {.offset = 6, .length = 7}
  43 #endif
  44                     }
  45 };
  46
  47 /*
  48 ** We treat the OOB for a 2K page as if it were 4 512 byte oobs,
  49 ** except the BI is at byte 0.
  50 */
  51 static struct nand_ecclayout nand_hw_eccoob_2048 = {
  52         /* Reserve 0 as BI indicator */
  53         .oobfree = {
  54 #if (NAND_ECC_NUM_BYTES > 10)
  55                     {.offset = 1, .length = 2},
  56 #elif (NAND_ECC_NUM_BYTES > 7)
  57                     {.offset = 1, .length = 5},
  58                     {.offset = 16, .length = 6},
  59                     {.offset = 32, .length = 6},
  60                     {.offset = 48, .length = 6}
  61 #else
  62                     {.offset = 1, .length = 8},
  63                     {.offset = 16, .length = 9},
  64                     {.offset = 32, .length = 9},
  65                     {.offset = 48, .length = 9}
  66 #endif
  67                     }
  68 };
  69
  70 /* We treat the OOB for a 4K page as if it were 8 512 byte oobs,
  71  * except the BI is at byte 0. */
  72 static struct nand_ecclayout nand_hw_eccoob_4096 = {
  73         /* Reserve 0 as BI indicator */
  74         .oobfree = {
  75 #if (NAND_ECC_NUM_BYTES > 10)
  76                     {.offset = 1, .length = 2},
  77                     {.offset = 16, .length = 3},
  78                     {.offset = 32, .length = 3},
  79                     {.offset = 48, .length = 3},
  80                     {.offset = 64, .length = 3},
  81                     {.offset = 80, .length = 3},
  82                     {.offset = 96, .length = 3},
  83                     {.offset = 112, .length = 3}
  84 #else
  85                     {.offset = 1, .length = 5},
  86                     {.offset = 16, .length = 6},
  87                     {.offset = 32, .length = 6},
  88                     {.offset = 48, .length = 6},
  89                     {.offset = 64, .length = 6},
  90                     {.offset = 80, .length = 6},
  91                     {.offset = 96, .length = 6},
  92                     {.offset = 112, .length = 6}
  93 #endif
  94                     }
  95 };
  96
  97 /* ---- Private Functions ------------------------------------------------ */
  98 /* ==== Public Functions ================================================= */
  99
 100 /****************************************************************************
 101 *
 102 *  bcm_umi_bch_read_page_hwecc - hardware ecc based page read function
 103 *  @mtd:        mtd info structure
 104 *  @chip:       nand chip info structure
 105 *  @buf:        buffer to store read data
 106 *  @oob_required:       caller expects OOB data read to chip->oob_poi
 107 *
 108 ***************************************************************************/
 109 static int bcm_umi_bch_read_page_hwecc(struct mtd_info *mtd,
 110                                        struct nand_chip *chip, uint8_t * buf,
 111                                        int oob_required, int page)
 112 {
 113         int sectorIdx = 0;
 114         int eccsize = chip->ecc.size;
 115         int eccsteps = chip->ecc.steps;
 116         uint8_t *datap = buf;
 117         uint8_t eccCalc[NAND_ECC_NUM_BYTES];
 118         int sectorOobSize = mtd->oobsize / eccsteps;
 119         int stat;
 120         unsigned int max_bitflips = 0;
 121
 122         for (sectorIdx = 0; sectorIdx < eccsteps;
 123                         sectorIdx++, datap += eccsize) {
 124                 if (sectorIdx > 0) {
 125                         /* Seek to page location within sector */
 126                         chip->cmdfunc(mtd, NAND_CMD_RNDOUT, sectorIdx * eccsize,
 127                                       -1);
 128                 }
 129
 130                 /* Enable hardware ECC before reading the buf */
 131                 nand_bcm_umi_bch_enable_read_hwecc();
 132
 133                 /* Read in data */
 134                 bcm_umi_nand_read_buf(mtd, datap, eccsize);
 135
 136                 /* Pause hardware ECC after reading the buf */
 137                 nand_bcm_umi_bch_pause_read_ecc_calc();
 138
 139                 /* Read the OOB ECC */
 140                 chip->cmdfunc(mtd, NAND_CMD_RNDOUT,
 141                               mtd->writesize + sectorIdx * sectorOobSize, -1);
 142                 nand_bcm_umi_bch_read_oobEcc(mtd->writesize, eccCalc,
 143                                              NAND_ECC_NUM_BYTES,
 144                                              chip->oob_poi +
 145                                              sectorIdx * sectorOobSize);
 146
 147                 /* Correct any ECC detected errors */
 148                 stat =
 149                     nand_bcm_umi_bch_correct_page(datap, eccCalc,
 150                                                   NAND_ECC_NUM_BYTES);
 151
 152                 /* Update Stats */
 153                 if (stat < 0) {
 154 #if defined(NAND_BCM_UMI_DEBUG)
 155                         printk(KERN_WARNING "%s uncorr_err sectorIdx=%d\n",
 156                                __func__, sectorIdx);
 157                         printk(KERN_WARNING
 158                                "%s data %02x %02x %02x %02x "
 159                                          "%02x %02x %02x %02x\n",
 160                                __func__, datap[0], datap[1], datap[2], datap[3],
 161                                datap[4], datap[5], datap[6], datap[7]);
 162                         printk(KERN_WARNING
 163                                "%s ecc  %02x %02x %02x %02x "
 164                                          "%02x %02x %02x %02x %02x %02x "
 165                                          "%02x %02x %02x\n",
 166                                __func__, eccCalc[0], eccCalc[1], eccCalc[2],
 167                                eccCalc[3], eccCalc[4], eccCalc[5], eccCalc[6],
 168                                eccCalc[7], eccCalc[8], eccCalc[9], eccCalc[10],
 169                                eccCalc[11], eccCalc[12]);
 170                         BUG();
 171 #endif
 172                         mtd->ecc_stats.failed++;
 173                 } else {
 174 #if defined(NAND_BCM_UMI_DEBUG)
 175                         if (stat > 0) {
 176                                 printk(KERN_INFO
 177                                        "%s %d correctable_errors detected\n",
 178                                        __func__, stat);
 179                         }
 180 #endif
 181                         mtd->ecc_stats.corrected += stat;
 182                         max_bitflips = max_t(unsigned int, max_bitflips, stat);
 183                 }
 184         }
 185         return max_bitflips;
 186 }
 187
 188 /****************************************************************************
 189 *
 190 *  bcm_umi_bch_write_page_hwecc - hardware ecc based page write function
 191 *  @mtd:        mtd info structure
 192 *  @chip:       nand chip info structure
 193 *  @buf:        data buffer
 194 *  @oob_required:       must write chip->oob_poi to OOB
 195 *
 196 ***************************************************************************/
 197 static void bcm_umi_bch_write_page_hwecc(struct mtd_info *mtd,
 198         struct nand_chip *chip, const uint8_t *buf, int oob_required)
 199 {
 200         int sectorIdx = 0;
 201         int eccsize = chip->ecc.size;
 202         int eccsteps = chip->ecc.steps;
 203         const uint8_t *datap = buf;
 204         uint8_t *oobp = chip->oob_poi;
 205         int sectorOobSize = mtd->oobsize / eccsteps;
 206
 207         for (sectorIdx = 0; sectorIdx < eccsteps;
 208              sectorIdx++, datap += eccsize, oobp += sectorOobSize) {
 209                 /* Enable hardware ECC before writing the buf */
 210                 nand_bcm_umi_bch_enable_write_hwecc();
 211                 bcm_umi_nand_write_buf(mtd, datap, eccsize);
 212                 nand_bcm_umi_bch_write_oobEcc(mtd->writesize, oobp,
 213                                               NAND_ECC_NUM_BYTES);
 214         }
 215
 216         bcm_umi_nand_write_buf(mtd, chip->oob_poi, mtd->oobsize);
 217 }