]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
mtd: nand: omap2: clean-up BCHx_HW and BCHx_SW ECC configurations in device_probe
authorPekon Gupta <pekon@ti.com>
Mon, 1 Jul 2013 09:51:50 +0000 (15:21 +0530)
committerArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Tue, 2 Jul 2013 07:29:53 +0000 (10:29 +0300)
ECC scheme on NAND devices can be implemented in multiple ways.Some using
Software algorithm, while others using in-build Hardware engines.
omap2-nand driver currently supports following flavours of ECC schemes.

+---------------------------------------+---------------+---------------+
| ECC scheme                            |ECC calculation|Error detection|
+---------------------------------------+---------------+---------------+
|OMAP_ECC_HAMMING_CODE_DEFAULT          |S/W            |S/W            |
|OMAP_ECC_HAMMING_CODE_HW               |H/W (GPMC)     |S/W            |
|OMAP_ECC_HAMMING_CODE_HW_ROMCODE       |H/W (GPMC)     |S/W            |
+---------------------------------------+---------------+---------------+
|(requires CONFIG_MTD_NAND_ECC_BCH)     |               |               |
|OMAP_ECC_BCH8_CODE_HW_DETECTION_SW     |H/W (GPMC)     |S/W            |
+---------------------------------------+---------------+---------------+
|(requires CONFIG_MTD_NAND_OMAP_BCH)    |               |               |
|OMAP_ECC_BCH8_CODE_HW                  |H/W (GPMC)     |H/W (ELM)      |
+---------------------------------------+---------------+---------------+

This patch
- separates the configurations for various ECC schemes.
- fixes dependency issues based on Kconfig options.
- cleans up redundant code

Signed-off-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
drivers/mtd/nand/omap2.c
include/linux/platform_data/elm.h

index daa3dfc2bda8ec55079140f81b6fee4570648d9c..c4c7e0d306f17e3ccd085b20f3cd269f153ebf38 100644 (file)
 #include <linux/of.h>
 #include <linux/of_device.h>
 
-#ifdef CONFIG_MTD_NAND_OMAP_BCH
+#ifdef CONFIG_MTD_NAND_ECC_BCH
 #include <linux/bch.h>
+#endif
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
 #include <linux/platform_data/elm.h>
 #endif
 
 #define BCH_ECC_SIZE0          0x0     /* ecc_size0 = 0, no oob protection */
 #define BCH_ECC_SIZE1          0x20    /* ecc_size1 = 32 */
 
+#define BADBLOCK_MARKER_LENGTH         0x2
+#define OMAP_ECC_BCH8_POLYNOMIAL       0x201b
+
 #ifdef CONFIG_MTD_NAND_OMAP_BCH
 static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
        0xac, 0x6b, 0xff, 0x99, 0x7b};
@@ -182,14 +187,11 @@ struct omap_nand_info {
        u_char                          *buf;
        int                                     buf_len;
        struct gpmc_nand_regs           reg;
-
-#ifdef CONFIG_MTD_NAND_OMAP_BCH
-       struct bch_control             *bch;
-       struct nand_ecclayout           ecclayout;
+       /* fields specific for BCHx_HW ECC scheme */
+       struct bch_control              *bch;
        bool                            is_elm_used;
        struct device                   *elm_dev;
        struct device_node              *of_node;
-#endif
 };
 
 /**
@@ -1058,8 +1060,6 @@ static int omap_dev_ready(struct mtd_info *mtd)
        }
 }
 
-#ifdef CONFIG_MTD_NAND_OMAP_BCH
-
 /**
  * omap3_enable_hwecc_bch - Program OMAP3 GPMC to perform BCH ECC correction
  * @mtd: MTD device structure
@@ -1141,6 +1141,7 @@ static void omap3_enable_hwecc_bch(struct mtd_info *mtd, int mode)
        writel(ECCCLEAR | ECC1, info->reg.gpmc_ecc_control);
 }
 
+#ifdef CONFIG_MTD_NAND_ECC_BCH
 /**
  * omap3_calculate_ecc_bch4 - Generate 7 bytes of ECC bytes
  * @mtd: MTD device structure
@@ -1226,6 +1227,62 @@ static int omap3_calculate_ecc_bch8(struct mtd_info *mtd, const u_char *dat,
        return 0;
 }
 
+/**
+ * omap3_correct_data_bch - Decode received data and correct errors
+ * @mtd: MTD device structure
+ * @data: page data
+ * @read_ecc: ecc read from nand flash
+ * @calc_ecc: ecc read from HW ECC registers
+ */
+static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data,
+                                 u_char *read_ecc, u_char *calc_ecc)
+{
+       int i, count;
+       /* cannot correct more than 8 errors */
+       unsigned int errloc[8];
+       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+                                                  mtd);
+
+       count = decode_bch(info->bch, NULL, 512, read_ecc, calc_ecc, NULL,
+                          errloc);
+       if (count > 0) {
+               /* correct errors */
+               for (i = 0; i < count; i++) {
+                       /* correct data only, not ecc bytes */
+                       if (errloc[i] < 8*512)
+                               data[errloc[i]/8] ^= 1 << (errloc[i] & 7);
+                       pr_debug("corrected bitflip %u\n", errloc[i]);
+               }
+       } else if (count < 0) {
+               pr_err("ecc unrecoverable error\n");
+       }
+       return count;
+}
+
+/**
+ * omap3_free_bch - Release BCH ecc resources
+ * @mtd: MTD device structure
+ */
+static void omap3_free_bch(struct mtd_info *mtd)
+{
+       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
+                                                  mtd);
+       if (info->bch) {
+               free_bch(info->bch);
+               info->bch = NULL;
+       }
+}
+
+#else
+
+static void omap3_free_bch(struct mtd_info *mtd)
+{
+}
+
+#endif /* CONFIG_MTD_NAND_ECC_BCH */
+
+
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
 /**
  * omap3_calculate_ecc_bch - Generate bytes of ECC bytes
  * @mtd:       MTD device structure
@@ -1518,38 +1575,6 @@ static int omap_elm_correct_data(struct mtd_info *mtd, u_char *data,
        return stat;
 }
 
-/**
- * omap3_correct_data_bch - Decode received data and correct errors
- * @mtd: MTD device structure
- * @data: page data
- * @read_ecc: ecc read from nand flash
- * @calc_ecc: ecc read from HW ECC registers
- */
-static int omap3_correct_data_bch(struct mtd_info *mtd, u_char *data,
-                                 u_char *read_ecc, u_char *calc_ecc)
-{
-       int i, count;
-       /* cannot correct more than 8 errors */
-       unsigned int errloc[8];
-       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
-                                                  mtd);
-
-       count = decode_bch(info->bch, NULL, 512, read_ecc, calc_ecc, NULL,
-                          errloc);
-       if (count > 0) {
-               /* correct errors */
-               for (i = 0; i < count; i++) {
-                       /* correct data only, not ecc bytes */
-                       if (errloc[i] < 8*512)
-                               data[errloc[i]/8] ^= 1 << (errloc[i] & 7);
-                       pr_debug("corrected bitflip %u\n", errloc[i]);
-               }
-       } else if (count < 0) {
-               pr_err("ecc unrecoverable error\n");
-       }
-       return count;
-}
-
 /**
  * omap_write_page_bch - BCH ecc based write page function for entire page
  * @mtd:               mtd info structure
@@ -1637,197 +1662,47 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 }
 
 /**
- * omap3_free_bch - Release BCH ecc resources
- * @mtd: MTD device structure
- */
-static void omap3_free_bch(struct mtd_info *mtd)
-{
-       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
-                                                  mtd);
-       if (info->bch) {
-               free_bch(info->bch);
-               info->bch = NULL;
-       }
-}
-
-/**
- * omap3_init_bch - Initialize BCH ECC
- * @mtd: MTD device structure
- * @ecc_opt: OMAP ECC mode (OMAP_ECC_BCH4_CODE_HW or OMAP_ECC_BCH8_CODE_HW)
+ * is_elm_present - checks for presence of ELM module by scanning DT nodes
+ * @omap_nand_info: NAND device structure containing platform data
+ * @bch_type: 0x0=BCH4, 0x1=BCH8, 0x2=BCH16
  */
-static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
+static int is_elm_present(struct omap_nand_info *info, int bch_type)
 {
-       int max_errors;
-       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
-                                                  mtd);
-#ifdef CONFIG_MTD_NAND_OMAP_BCH8
-       const int hw_errors = BCH8_MAX_ERROR;
-#else
-       const int hw_errors = BCH4_MAX_ERROR;
-#endif
-       enum bch_ecc bch_type;
        const __be32 *parp;
        int lenp;
        struct device_node *elm_node;
-
-       info->bch = NULL;
-
-       max_errors = (ecc_opt == OMAP_ECC_BCH8_CODE_HW) ?
-               BCH8_MAX_ERROR : BCH4_MAX_ERROR;
-       if (max_errors != hw_errors) {
-               pr_err("cannot configure %d-bit BCH ecc, only %d-bit supported",
-                      max_errors, hw_errors);
-               goto fail;
-       }
-
-       info->nand.ecc.size = 512;
-       info->nand.ecc.hwctl = omap3_enable_hwecc_bch;
-       info->nand.ecc.mode = NAND_ECC_HW;
-       info->nand.ecc.strength = max_errors;
-
-       if (hw_errors == BCH8_MAX_ERROR)
-               bch_type = BCH8_ECC;
-       else
-               bch_type = BCH4_ECC;
+       struct platform_device *pdev;
+       info->is_elm_used = false;
 
        /* Detect availability of ELM module */
        parp = of_get_property(info->of_node, "elm_id", &lenp);
        if ((parp == NULL) && (lenp != (sizeof(void *) * 2))) {
                pr_err("Missing elm_id property, fall back to Software BCH\n");
-               info->is_elm_used = false;
        } else {
-               struct platform_device *pdev;
-
                elm_node = of_find_node_by_phandle(be32_to_cpup(parp));
                pdev = of_find_device_by_node(elm_node);
                info->elm_dev = &pdev->dev;
-
-               if (elm_config(info->elm_dev, bch_type) == 0)
-                       info->is_elm_used = true;
-       }
-
-       if (info->is_elm_used && (mtd->writesize <= 4096)) {
-
-               if (hw_errors == BCH8_MAX_ERROR)
-                       info->nand.ecc.bytes = BCH8_SIZE;
-               else
-                       info->nand.ecc.bytes = BCH4_SIZE;
-
-               info->nand.ecc.correct = omap_elm_correct_data;
-               info->nand.ecc.calculate = omap3_calculate_ecc_bch;
-               info->nand.ecc.read_page = omap_read_page_bch;
-               info->nand.ecc.write_page = omap_write_page_bch;
-       } else {
-               /*
-                * software bch library is only used to detect and
-                * locate errors
-                */
-               info->bch = init_bch(13, max_errors,
-                               0x201b /* hw polynomial */);
-               if (!info->bch)
-                       goto fail;
-
-               info->nand.ecc.correct = omap3_correct_data_bch;
-
-               /*
-                * The number of corrected errors in an ecc block that will
-                * trigger block scrubbing defaults to the ecc strength (4 or 8)
-                * Set mtd->bitflip_threshold here to define a custom threshold.
-                */
-
-               if (max_errors == 8) {
-                       info->nand.ecc.bytes = 13;
-                       info->nand.ecc.calculate = omap3_calculate_ecc_bch8;
-               } else {
-                       info->nand.ecc.bytes = 7;
-                       info->nand.ecc.calculate = omap3_calculate_ecc_bch4;
-               }
-       }
-
-       pr_info("enabling NAND BCH ecc with %d-bit correction\n", max_errors);
-       return 0;
-fail:
-       omap3_free_bch(mtd);
-       return -1;
-}
-
-/**
- * omap3_init_bch_tail - Build an oob layout for BCH ECC correction.
- * @mtd: MTD device structure
- */
-static int omap3_init_bch_tail(struct mtd_info *mtd)
-{
-       int i, steps, offset;
-       struct omap_nand_info *info = container_of(mtd, struct omap_nand_info,
-                                                  mtd);
-       struct nand_ecclayout *layout = &info->ecclayout;
-
-       /* build oob layout */
-       steps = mtd->writesize/info->nand.ecc.size;
-       layout->eccbytes = steps*info->nand.ecc.bytes;
-
-       /* do not bother creating special oob layouts for small page devices */
-       if (mtd->oobsize < 64) {
-               pr_err("BCH ecc is not supported on small page devices\n");
-               goto fail;
-       }
-
-       /* reserve 2 bytes for bad block marker */
-       if (layout->eccbytes+2 > mtd->oobsize) {
-               pr_err("no oob layout available for oobsize %d eccbytes %u\n",
-                      mtd->oobsize, layout->eccbytes);
-               goto fail;
+               /* ELM module available, now configure it */
+               elm_config(info->elm_dev, bch_type);
+               info->is_elm_used = true;
+               return 0;
        }
 
-       /* ECC layout compatible with RBL for BCH8 */
-       if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE))
-               offset = 2;
-       else
-               offset = mtd->oobsize - layout->eccbytes;
-
-       /* put ecc bytes at oob tail */
-       for (i = 0; i < layout->eccbytes; i++)
-               layout->eccpos[i] = offset + i;
-
-       if (info->is_elm_used && (info->nand.ecc.bytes == BCH8_SIZE))
-               layout->oobfree[0].offset = 2 + layout->eccbytes * steps;
-       else
-               layout->oobfree[0].offset = 2;
-
-       layout->oobfree[0].length = mtd->oobsize-2-layout->eccbytes;
-       info->nand.ecc.layout = layout;
-
-       if (!(info->nand.options & NAND_BUSWIDTH_16))
-               info->nand.badblock_pattern = &bb_descrip_flashbased;
-       return 0;
-fail:
-       omap3_free_bch(mtd);
-       return -1;
-}
-
-#else
-static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
-{
-       pr_err("CONFIG_MTD_NAND_OMAP_BCH is not enabled\n");
-       return -1;
-}
-static int omap3_init_bch_tail(struct mtd_info *mtd)
-{
-       return -1;
-}
-static void omap3_free_bch(struct mtd_info *mtd)
-{
+       return -ENODEV;
 }
 #endif /* CONFIG_MTD_NAND_OMAP_BCH */
 
+
 static int omap_nand_probe(struct platform_device *pdev)
 {
        struct omap_nand_info           *info;
        struct omap_nand_platform_data  *pdata;
+       struct mtd_info                 *mtd;
+       struct nand_chip                *chip;
        int                             err;
-       int                             i, offset;
-       dma_cap_mask_t mask;
-       unsigned sig;
+       int                             i;
+       dma_cap_mask_t                  mask;
+       unsigned                        sig;
        struct resource                 *res;
        struct mtd_part_parser_data     ppdata = {};
 
@@ -1846,16 +1721,18 @@ static int omap_nand_probe(struct platform_device *pdev)
        spin_lock_init(&info->controller.lock);
        init_waitqueue_head(&info->controller.wq);
 
-       info->pdev = pdev;
+       mtd                     = &info->mtd;
+       mtd->name               = dev_name(&pdev->dev);
+       mtd->owner              = THIS_MODULE;
+       mtd->priv               = &info->nand;
+       chip                    = mtd->priv;
 
+       info->pdev              = pdev;
        info->gpmc_cs           = pdata->cs;
        info->reg               = pdata->reg;
+       info->bch               = NULL;
 
-       info->mtd.priv          = &info->nand;
-       info->mtd.name          = dev_name(&pdev->dev);
-       info->mtd.owner         = THIS_MODULE;
-
-       info->nand.options      = pdata->devsize;
+       info->nand.options      = NAND_BUSWIDTH_AUTO;
        info->nand.options      |= NAND_SKIP_BBTSCAN;
 #ifdef CONFIG_MTD_NAND_OMAP_BCH
        info->of_node           = pdata->of_node;
@@ -1903,6 +1780,31 @@ static int omap_nand_probe(struct platform_device *pdev)
                info->nand.chip_delay = 50;
        }
 
+       /* scan NAND device conncted to controller */
+       if (nand_scan_ident(mtd, 1, NULL)) {
+               err = -ENXIO;
+               goto out_release_mem_region;
+       }
+       pr_info("%s: detected %s NAND flash\n", DRIVER_NAME,
+                       (info->nand.options & NAND_BUSWIDTH_16) ? "x16" : "x8");
+       if ((info->nand.options & NAND_BUSWIDTH_16) !=
+                       (pdata->devsize & NAND_BUSWIDTH_16)) {
+               pr_err("%s: but incorrectly configured as %s", DRIVER_NAME,
+                       (pdata->devsize & NAND_BUSWIDTH_16) ? "x16" : "x8");
+               err = -EINVAL;
+               goto out_release_mem_region;
+       }
+
+       /* check for small page devices */
+       if ((mtd->oobsize < 64) &&
+               (pdata->ecc_opt != OMAP_ECC_HAMMING_CODE_DEFAULT) &&
+               (pdata->ecc_opt != OMAP_ECC_HAMMING_CODE_HW)) {
+               pr_err("small page devices are not supported\n");
+               err = -EINVAL;
+               goto out_release_mem_region;
+       }
+
+       /* populate read & write API based on xfer_type selected */
        switch (pdata->xfer_type) {
        case NAND_OMAP_PREFETCH_POLLED:
                info->nand.read_buf   = omap_read_buf_pref;
@@ -1992,66 +1894,154 @@ static int omap_nand_probe(struct platform_device *pdev)
                goto out_release_mem_region;
        }
 
-       /* select the ecc type */
-       if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_DEFAULT)
-               info->nand.ecc.mode = NAND_ECC_SOFT;
-       else if ((pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW) ||
-               (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE)) {
+       /* populate MTD interface based on ECC scheme */
+       switch (pdata->ecc_opt) {
+       case OMAP_ECC_HAMMING_CODE_DEFAULT:
+               pr_info("using OMAP_ECC_HAMMING_CODE_DEFAULT ECC scheme\n");
+               info->nand.ecc.mode             = NAND_ECC_SOFT;
+               goto generic_ecc_layout;
+
+       case OMAP_ECC_HAMMING_CODE_HW:
+               pr_info("using OMAP_ECC_HAMMING_CODE_HW ECC scheme\n");
+               info->nand.ecc.mode             = NAND_ECC_HW;
                info->nand.ecc.bytes            = 3;
                info->nand.ecc.size             = 512;
                info->nand.ecc.strength         = 1;
                info->nand.ecc.calculate        = omap_calculate_ecc;
                info->nand.ecc.hwctl            = omap_enable_hwecc;
                info->nand.ecc.correct          = omap_correct_data;
+               goto generic_ecc_layout;
+
+       case OMAP_ECC_HAMMING_CODE_HW_ROMCODE:
+               pr_info("using OMAP_ECC_HAMMING_CODE_HW_ROMCODE ECC scheme\n");
                info->nand.ecc.mode             = NAND_ECC_HW;
-       } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
-                  (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
-               err = omap3_init_bch(&info->mtd, pdata->ecc_opt);
-               if (err) {
+               info->nand.ecc.bytes            = 3;
+               info->nand.ecc.size             = 512;
+               info->nand.ecc.strength         = 1;
+               info->nand.ecc.calculate        = omap_calculate_ecc;
+               info->nand.ecc.hwctl            = omap_enable_hwecc;
+               info->nand.ecc.correct          = omap_correct_data;
+               /* define custom ECC layout */
+               omap_oobinfo.eccbytes           = info->nand.ecc.bytes *
+                                                       (mtd->writesize /
+                                                       info->nand.ecc.size);
+               if (info->nand.options & NAND_BUSWIDTH_16)
+                       omap_oobinfo.eccpos[0]  = BADBLOCK_MARKER_LENGTH;
+               else
+                       omap_oobinfo.eccpos[0]  = 1;
+               omap_oobinfo.oobfree->offset    = omap_oobinfo.eccpos[0] +
+                                                       omap_oobinfo.eccbytes;
+               goto custom_ecc_layout;
+
+#ifdef CONFIG_MTD_NAND_OMAP_BCH
+       case OMAP_ECC_BCH8_CODE_HW:
+               pr_info("using OMAP_ECC_BCH8_CODE_HW ECC scheme\n");
+               if (is_elm_present(info, ECC_TYPE_BCH8) < 0) {
+                       pr_err("ELM module not detected, required for ECC\n");
                        err = -EINVAL;
                        goto out_release_mem_region;
                }
-       }
-
-       /* DIP switches on some boards change between 8 and 16 bit
-        * bus widths for flash.  Try the other width if the first try fails.
-        */
-       if (nand_scan_ident(&info->mtd, 1, NULL)) {
-               info->nand.options ^= NAND_BUSWIDTH_16;
-               if (nand_scan_ident(&info->mtd, 1, NULL)) {
-                       err = -ENXIO;
+               info->nand.ecc.mode             = NAND_ECC_HW;
+               info->nand.ecc.size             = 512;
+               /* 14th bit is kept reserved for ROM-code compatibility */
+               info->nand.ecc.bytes            = 13 + 1;
+               info->nand.ecc.strength         = 8;
+               info->nand.ecc.hwctl            = omap3_enable_hwecc_bch;
+               info->nand.ecc.correct          = omap_elm_correct_data;
+               info->nand.ecc.calculate        = omap3_calculate_ecc_bch;
+               info->nand.ecc.read_page        = omap_read_page_bch;
+               info->nand.ecc.write_page       = omap_write_page_bch;
+               /* define custom ECC layout */
+               omap_oobinfo.eccbytes           = info->nand.ecc.bytes *
+                                                       (mtd->writesize /
+                                                       info->nand.ecc.size);
+               omap_oobinfo.eccpos[0]          = BADBLOCK_MARKER_LENGTH;
+               omap_oobinfo.oobfree->offset    = omap_oobinfo.eccpos[0] +
+                                                       omap_oobinfo.eccbytes;
+               goto custom_ecc_layout;
+#endif
+#ifdef CONFIG_MTD_NAND_ECC_BCH
+       case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
+               pr_info("using OMAP_ECC_BCH8_CODE_HW_DETECTION_SW ECC\n");
+               info->nand.ecc.mode             = NAND_ECC_HW;
+               info->nand.ecc.size             = 512;
+               info->nand.ecc.bytes            = 13;
+               info->nand.ecc.strength         = 8;
+               info->nand.ecc.hwctl            = omap3_enable_hwecc_bch;
+               info->nand.ecc.correct          = omap3_correct_data_bch;
+               info->nand.ecc.calculate        = omap3_calculate_ecc_bch8;
+               /* define custom ECC layout */
+               omap_oobinfo.eccbytes           = info->nand.ecc.bytes *
+                                                       (mtd->writesize /
+                                                       info->nand.ecc.size);
+               omap_oobinfo.eccpos[0]          = info->mtd.oobsize -
+                                                       omap_oobinfo.eccbytes;
+               omap_oobinfo.oobfree->offset    = BADBLOCK_MARKER_LENGTH;
+               /* software bch library is used for locating errors */
+               info->bch = init_bch(info->nand.ecc.bytes,
+                                       info->nand.ecc.strength,
+                                       OMAP_ECC_BCH8_POLYNOMIAL);
+               if (!info->bch) {
+                       pr_err("unable initialize S/W BCH logic\n");
+                       err = -EINVAL;
                        goto out_release_mem_region;
                }
-       }
-
-       /* rom code layout */
-       if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE) {
-
-               if (info->nand.options & NAND_BUSWIDTH_16)
-                       offset = 2;
-               else {
-                       offset = 1;
-                       info->nand.badblock_pattern = &bb_descrip_flashbased;
-               }
-               omap_oobinfo.eccbytes = 3 * (info->mtd.oobsize/16);
-               for (i = 0; i < omap_oobinfo.eccbytes; i++)
-                       omap_oobinfo.eccpos[i] = i+offset;
-
-               omap_oobinfo.oobfree->offset = offset + omap_oobinfo.eccbytes;
-               omap_oobinfo.oobfree->length = info->mtd.oobsize -
-                                       (offset + omap_oobinfo.eccbytes);
-
-               info->nand.ecc.layout = &omap_oobinfo;
-       } else if ((pdata->ecc_opt == OMAP_ECC_BCH4_CODE_HW) ||
-                  (pdata->ecc_opt == OMAP_ECC_BCH8_CODE_HW)) {
-               /* build OOB layout for BCH ECC correction */
-               err = omap3_init_bch_tail(&info->mtd);
-               if (err) {
+               goto custom_ecc_layout;
+
+       case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
+               pr_info("using OMAP_ECC_BCH4_CODE_HW_DETECTION_SW ECC\n");
+               info->nand.ecc.mode             = NAND_ECC_HW;
+               info->nand.ecc.size             = 512;
+               info->nand.ecc.bytes            = 7;
+               info->nand.ecc.strength         = 4;
+               info->nand.ecc.hwctl            = omap3_enable_hwecc_bch;
+               info->nand.ecc.correct          = omap3_correct_data_bch;
+               info->nand.ecc.calculate        = omap3_calculate_ecc_bch4;
+               /* define custom ECC layout */
+               omap_oobinfo.eccbytes           = info->nand.ecc.bytes *
+                                                       (mtd->writesize /
+                                                       info->nand.ecc.size);
+               omap_oobinfo.eccpos[0]          = info->mtd.oobsize -
+                                                       omap_oobinfo.eccbytes;
+               omap_oobinfo.oobfree->offset    = BADBLOCK_MARKER_LENGTH;
+               /* software bch library is used for locating errors */
+               info->bch = init_bch(info->nand.ecc.bytes,
+                                       info->nand.ecc.strength,
+                                       OMAP_ECC_BCH8_POLYNOMIAL);
+               if (!info->bch) {
+                       pr_err("unable initialize S/W BCH logic\n");
                        err = -EINVAL;
                        goto out_release_mem_region;
                }
+               goto custom_ecc_layout;
+#endif
+       default:
+               pr_err("selected ECC scheme not supported or not enabled\n");
+               err = -EINVAL;
+               goto out_release_mem_region;
+       }
+
+custom_ecc_layout:
+       /* populate remaining info for custom ecc layout */
+       pr_info("%s: using custom ecc layout\n", DRIVER_NAME);
+       omap_oobinfo.oobfree->length = mtd->oobsize - BADBLOCK_MARKER_LENGTH
+                                               - omap_oobinfo.eccbytes;
+       if (!(info->nand.options & NAND_BUSWIDTH_16))
+               info->nand.badblock_pattern = &bb_descrip_flashbased;
+       for (i = 1; i < omap_oobinfo.eccbytes; i++)
+               omap_oobinfo.eccpos[i] = omap_oobinfo.eccpos[0] + i;
+
+       /* check if NAND OOBSIZE meets ECC scheme requirement */
+       if (mtd->oobsize < (omap_oobinfo.eccbytes +
+                                       BADBLOCK_MARKER_LENGTH)) {
+               pr_err("not enough OOB bytes required = %d, available=%d\n",
+                      mtd->oobsize, omap_oobinfo.eccbytes);
+               err = -EINVAL;
+               goto out_release_mem_region;
        }
+       info->nand.ecc.layout = &omap_oobinfo;
 
+generic_ecc_layout:
        /* second phase scan */
        if (nand_scan_tail(&info->mtd)) {
                err = -ENXIO;
@@ -2075,11 +2065,13 @@ out_release_mem_region:
                free_irq(info->gpmc_irq_fifo, info);
        release_mem_region(info->phys_base, info->mem_size);
 out_free_info:
+       omap3_free_bch(&info->mtd);
        kfree(info);
 
        return err;
 }
 
+
 static int omap_nand_remove(struct platform_device *pdev)
 {
        struct mtd_info *mtd = platform_get_drvdata(pdev);
index bf0a83b7ed9d3e0538cc09c57f7d498065931501..5e36e4205043239073fe5dcec4a73da465611ff3 100644 (file)
@@ -23,6 +23,10 @@ enum bch_ecc {
        BCH8_ECC,
 };
 
+#define ECC_TYPE_BCH4                (0x0 << 0)
+#define ECC_TYPE_BCH8                (0x1 << 0)
+#define ECC_TYPE_BCH16               (0x2 << 0)
+
 /* ELM support 8 error syndrome process */
 #define ERROR_VECTOR_MAX               8