+#endif /* CONFIG_NAND_OMAP_ELM */
+
+/*
+ * OMAP3 BCH8 support (with BCH library)
+ */
+#ifdef CONFIG_BCH
+/**
+ * omap_correct_data_bch_sw - 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 omap_correct_data_bch_sw(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 nand_chip *chip = mtd_to_nand(mtd);
+ struct omap_nand_info *info = nand_get_controller_data(chip);
+
+ count = decode_bch(info->control, NULL, SECTOR_BYTES,
+ 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] < SECTOR_BYTES << 3)
+ data[errloc[i] >> 3] ^= 1 << (errloc[i] & 7);
+ debug("corrected bitflip %u\n", errloc[i]);
+#ifdef DEBUG
+ puts("read_ecc: ");
+ /*
+ * BCH8 have 13 bytes of ECC; BCH4 needs adoption
+ * here!
+ */
+ for (i = 0; i < 13; i++)
+ printf("%02x ", read_ecc[i]);
+ puts("\n");
+ puts("calc_ecc: ");
+ for (i = 0; i < 13; i++)
+ printf("%02x ", calc_ecc[i]);
+ puts("\n");
+#endif
+ }
+ } else if (count < 0) {
+ puts("ecc unrecoverable error\n");
+ }
+ return count;
+}
+
+/**
+ * omap_free_bch - Release BCH ecc resources
+ * @mtd: MTD device structure
+ */
+static void __maybe_unused omap_free_bch(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct omap_nand_info *info = nand_get_controller_data(chip);
+
+ if (info->control) {
+ free_bch(info->control);
+ info->control = NULL;
+ }
+}
+#endif /* CONFIG_BCH */
+
+/**
+ * omap_select_ecc_scheme - configures driver for particular ecc-scheme
+ * @nand: NAND chip device structure
+ * @ecc_scheme: ecc scheme to configure
+ * @pagesize: number of main-area bytes per page of NAND device
+ * @oobsize: number of OOB/spare bytes per page of NAND device
+ */
+static int omap_select_ecc_scheme(struct nand_chip *nand,
+ enum omap_ecc ecc_scheme, unsigned int pagesize, unsigned int oobsize) {
+ struct omap_nand_info *info = nand_get_controller_data(nand);
+ struct nand_ecclayout *ecclayout = &omap_ecclayout;
+ int eccsteps = pagesize / SECTOR_BYTES;
+ int i;
+
+ switch (ecc_scheme) {
+ case OMAP_ECC_HAM1_CODE_SW:
+ debug("nand: selected OMAP_ECC_HAM1_CODE_SW\n");
+ /* For this ecc-scheme, ecc.bytes, ecc.layout, ... are
+ * initialized in nand_scan_tail(), so just set ecc.mode */
+ info->control = NULL;
+ nand->ecc.mode = NAND_ECC_SOFT;
+ nand->ecc.layout = NULL;
+ nand->ecc.size = 0;
+ break;
+
+ case OMAP_ECC_HAM1_CODE_HW:
+ debug("nand: selected OMAP_ECC_HAM1_CODE_HW\n");
+ /* check ecc-scheme requirements before updating ecc info */
+ if ((3 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
+ printf("nand: error: insufficient OOB: require=%d\n", (
+ (3 * eccsteps) + BADBLOCK_MARKER_LENGTH));
+ return -EINVAL;
+ }
+ info->control = NULL;
+ /* populate ecc specific fields */
+ memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
+ nand->ecc.mode = NAND_ECC_HW;
+ nand->ecc.strength = 1;
+ nand->ecc.size = SECTOR_BYTES;
+ nand->ecc.bytes = 3;
+ nand->ecc.hwctl = omap_enable_hwecc;
+ nand->ecc.correct = omap_correct_data;
+ nand->ecc.calculate = omap_calculate_ecc;
+ /* define ecc-layout */
+ ecclayout->eccbytes = nand->ecc.bytes * eccsteps;
+ for (i = 0; i < ecclayout->eccbytes; i++) {
+ if (nand->options & NAND_BUSWIDTH_16)
+ ecclayout->eccpos[i] = i + 2;
+ else
+ ecclayout->eccpos[i] = i + 1;
+ }
+ ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
+ BADBLOCK_MARKER_LENGTH;
+ break;
+
+ case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
+#ifdef CONFIG_BCH
+ debug("nand: selected OMAP_ECC_BCH8_CODE_HW_DETECTION_SW\n");
+ /* check ecc-scheme requirements before updating ecc info */
+ if ((13 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
+ printf("nand: error: insufficient OOB: require=%d\n", (
+ (13 * eccsteps) + BADBLOCK_MARKER_LENGTH));
+ return -EINVAL;
+ }
+ /* check if BCH S/W library can be used for error detection */
+ info->control = init_bch(13, 8, 0x201b);
+ if (!info->control) {
+ printf("nand: error: could not init_bch()\n");
+ return -ENODEV;
+ }
+ /* populate ecc specific fields */
+ memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
+ nand->ecc.mode = NAND_ECC_HW;
+ nand->ecc.strength = 8;
+ nand->ecc.size = SECTOR_BYTES;
+ nand->ecc.bytes = 13;
+ nand->ecc.hwctl = omap_enable_hwecc;
+ nand->ecc.correct = omap_correct_data_bch_sw;
+ nand->ecc.calculate = omap_calculate_ecc;
+ /* define ecc-layout */
+ ecclayout->eccbytes = nand->ecc.bytes * eccsteps;
+ ecclayout->eccpos[0] = BADBLOCK_MARKER_LENGTH;
+ for (i = 1; i < ecclayout->eccbytes; i++) {
+ if (i % nand->ecc.bytes)
+ ecclayout->eccpos[i] =
+ ecclayout->eccpos[i - 1] + 1;
+ else
+ ecclayout->eccpos[i] =
+ ecclayout->eccpos[i - 1] + 2;
+ }
+ ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
+ BADBLOCK_MARKER_LENGTH;
+ break;
+#else
+ printf("nand: error: CONFIG_BCH required for ECC\n");
+ return -EINVAL;
+#endif
+
+ case OMAP_ECC_BCH8_CODE_HW:
+#ifdef CONFIG_NAND_OMAP_ELM
+ debug("nand: selected OMAP_ECC_BCH8_CODE_HW\n");
+ /* check ecc-scheme requirements before updating ecc info */
+ if ((14 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
+ printf("nand: error: insufficient OOB: require=%d\n", (
+ (14 * eccsteps) + BADBLOCK_MARKER_LENGTH));
+ return -EINVAL;
+ }
+ /* intialize ELM for ECC error detection */
+ elm_init();
+ info->control = NULL;
+ /* populate ecc specific fields */
+ memset(&nand->ecc, 0, sizeof(struct nand_ecc_ctrl));
+ nand->ecc.mode = NAND_ECC_HW;
+ nand->ecc.strength = 8;
+ nand->ecc.size = SECTOR_BYTES;
+ nand->ecc.bytes = 14;
+ nand->ecc.hwctl = omap_enable_hwecc;
+ nand->ecc.correct = omap_correct_data_bch;
+ nand->ecc.calculate = omap_calculate_ecc;
+ nand->ecc.read_page = omap_read_page_bch;
+ /* define ecc-layout */
+ ecclayout->eccbytes = nand->ecc.bytes * eccsteps;
+ for (i = 0; i < ecclayout->eccbytes; i++)
+ ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].length = oobsize - ecclayout->eccbytes -
+ BADBLOCK_MARKER_LENGTH;
+ break;
+#else
+ printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
+ return -EINVAL;
+#endif
+
+ case OMAP_ECC_BCH16_CODE_HW:
+#ifdef CONFIG_NAND_OMAP_ELM
+ debug("nand: using OMAP_ECC_BCH16_CODE_HW\n");
+ /* check ecc-scheme requirements before updating ecc info */
+ if ((26 * eccsteps) + BADBLOCK_MARKER_LENGTH > oobsize) {
+ printf("nand: error: insufficient OOB: require=%d\n", (
+ (26 * eccsteps) + BADBLOCK_MARKER_LENGTH));
+ return -EINVAL;
+ }
+ /* intialize ELM for ECC error detection */
+ elm_init();
+ /* populate ecc specific fields */
+ nand->ecc.mode = NAND_ECC_HW;
+ nand->ecc.size = SECTOR_BYTES;
+ nand->ecc.bytes = 26;
+ nand->ecc.strength = 16;
+ nand->ecc.hwctl = omap_enable_hwecc;
+ nand->ecc.correct = omap_correct_data_bch;
+ nand->ecc.calculate = omap_calculate_ecc;
+ nand->ecc.read_page = omap_read_page_bch;
+ /* define ecc-layout */
+ ecclayout->eccbytes = nand->ecc.bytes * eccsteps;
+ for (i = 0; i < ecclayout->eccbytes; i++)
+ ecclayout->eccpos[i] = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].offset = i + BADBLOCK_MARKER_LENGTH;
+ ecclayout->oobfree[0].length = oobsize - nand->ecc.bytes -
+ BADBLOCK_MARKER_LENGTH;
+ break;
+#else
+ printf("nand: error: CONFIG_NAND_OMAP_ELM required for ECC\n");
+ return -EINVAL;
+#endif
+ default:
+ debug("nand: error: ecc scheme not enabled or supported\n");
+ return -EINVAL;
+ }
+
+ /* nand_scan_tail() sets ham1 sw ecc; hw ecc layout is set by driver */
+ if (ecc_scheme != OMAP_ECC_HAM1_CODE_SW)
+ nand->ecc.layout = ecclayout;
+
+ info->ecc_scheme = ecc_scheme;
+ return 0;
+}