mtd: nand: brcm: switch to mtd_ooblayout_ops

Implementing the mtd_ooblayout_ops interface is the new way of exposing
ECC/OOB layout to MTD users.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

1 files changed, 157 insertions, 101 deletions

diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
index e5f281f148dc..c3331ffcaffd 100644
--- a/drivers/mtd/nand/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/brcmnand/brcmnand.c
@@ -780,127 +780,183 @@ static inline bool is_hamming_ecc(struct brcmnand_cfg *cfg)
 }
 
 /*
- * Returns a nand_ecclayout strucutre for the given layout/configuration.
- * Returns NULL on failure.
+ * Set mtd->ooblayout to the appropriate mtd_ooblayout_ops given
+ * the layout/configuration.
+ * Returns -ERRCODE on failure.
  */
-static struct nand_ecclayout *brcmnand_create_layout(int ecc_level,
-                                                     struct brcmnand_host *host)
+static int brcmnand_hamming_ooblayout_ecc(struct mtd_info *mtd, int section,
+                                          struct mtd_oob_region *oobregion)
 {
+        struct nand_chip *chip = mtd_to_nand(mtd);
+        struct brcmnand_host *host = nand_get_controller_data(chip);
         struct brcmnand_cfg *cfg = &host->hwcfg;
-        int i, j;
-        struct nand_ecclayout *layout;
-        int req;
-        int sectors;
-        int sas;
-        int idx1, idx2;
-
-        layout = devm_kzalloc(&host->pdev->dev, sizeof(*layout), GFP_KERNEL);
-        if (!layout)
-                return NULL;
-
-        sectors = cfg->page_size / (512 << cfg->sector_size_1k);
-        sas = cfg->spare_area_size << cfg->sector_size_1k;
-
-        /* Hamming */
-        if (is_hamming_ecc(cfg)) {
-                for (i = 0, idx1 = 0, idx2 = 0; i < sectors; i++) {
-                        /* First sector of each page may have BBI */
-                        if (i == 0) {
-                                layout->oobfree[idx2].offset = i * sas + 1;
-                                /* Small-page NAND use byte 6 for BBI */
-                                if (cfg->page_size == 512)
-                                        layout->oobfree[idx2].offset--;
-                                layout->oobfree[idx2].length = 5;
-                        } else {
-                                layout->oobfree[idx2].offset = i * sas;
-                                layout->oobfree[idx2].length = 6;
-                        }
-                        idx2++;
-                        layout->eccpos[idx1++] = i * sas + 6;
-                        layout->eccpos[idx1++] = i * sas + 7;
-                        layout->eccpos[idx1++] = i * sas + 8;
-                        layout->oobfree[idx2].offset = i * sas + 9;
-                        layout->oobfree[idx2].length = 7;
-                        idx2++;
-                        /* Leave zero-terminated entry for OOBFREE */
-                        if (idx1 >= MTD_MAX_ECCPOS_ENTRIES_LARGE ||
-                                    idx2 >= MTD_MAX_OOBFREE_ENTRIES_LARGE - 1)
-                                break;
-                }
+        int sas = cfg->spare_area_size << cfg->sector_size_1k;
+        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
 
-                return layout;
-        }
+        if (section >= sectors)
+                return -ERANGE;
 
-        /*
-         * CONTROLLER_VERSION:
-         *   < v5.0: ECC_REQ = ceil(BCH_T * 13/8)
-         *  >= v5.0: ECC_REQ = ceil(BCH_T * 14/8)
-         * But we will just be conservative.
-         */
-        req = DIV_ROUND_UP(ecc_level * 14, 8);
-        if (req >= sas) {
-                dev_err(&host->pdev->dev,
-                        "error: ECC too large for OOB (ECC bytes %d, spare sector %d)\n",
-                        req, sas);
-                return NULL;
-        }
+        oobregion->offset = (section * sas) + 6;
+        oobregion->length = 3;
+
+        return 0;
+}
+
+static int brcmnand_hamming_ooblayout_free(struct mtd_info *mtd, int section,
+                                           struct mtd_oob_region *oobregion)
+{
+        struct nand_chip *chip = mtd_to_nand(mtd);
+        struct brcmnand_host *host = nand_get_controller_data(chip);
+        struct brcmnand_cfg *cfg = &host->hwcfg;
+        int sas = cfg->spare_area_size << cfg->sector_size_1k;
+        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
+
+        if (section >= sectors * 2)
+                return -ERANGE;
 
-        layout->eccbytes = req * sectors;
-        for (i = 0, idx1 = 0, idx2 = 0; i < sectors; i++) {
-                for (j = sas - req; j < sas && idx1 <
-                                MTD_MAX_ECCPOS_ENTRIES_LARGE; j++, idx1++)
-                        layout->eccpos[idx1] = i * sas + j;
+        oobregion->offset = (section / 2) * sas;
+
+        if (section & 1) {
+                oobregion->offset += 9;
+                oobregion->length = 7;
+        } else {
+                oobregion->length = 6;
 
                 /* First sector of each page may have BBI */
-                if (i == 0) {
-                        if (cfg->page_size == 512 && (sas - req >= 6)) {
-                                /* Small-page NAND use byte 6 for BBI */
-                                layout->oobfree[idx2].offset = 0;
-                                layout->oobfree[idx2].length = 5;
-                                idx2++;
-                                if (sas - req > 6) {
-                                        layout->oobfree[idx2].offset = 6;
-                                        layout->oobfree[idx2].length =
-                                                sas - req - 6;
-                                        idx2++;
-                                }
-                        } else if (sas > req + 1) {
-                                layout->oobfree[idx2].offset = i * sas + 1;
-                                layout->oobfree[idx2].length = sas - req - 1;
-                                idx2++;
-                        }
-                } else if (sas > req) {
-                        layout->oobfree[idx2].offset = i * sas;
-                        layout->oobfree[idx2].length = sas - req;
-                        idx2++;
+                if (!section) {
+                        /*
+                         * Small-page NAND use byte 6 for BBI while large-page
+                         * NAND use byte 0.
+                         */
+                        if (cfg->page_size > 512)
+                                oobregion->offset++;
+                        oobregion->length--;
                 }
-                /* Leave zero-terminated entry for OOBFREE */
-                if (idx1 >= MTD_MAX_ECCPOS_ENTRIES_LARGE ||
-                                idx2 >= MTD_MAX_OOBFREE_ENTRIES_LARGE - 1)
-                        break;
         }
 
-        return layout;
+        return 0;
+}
+
+static const struct mtd_ooblayout_ops brcmnand_hamming_ooblayout_ops = {
+        .ecc = brcmnand_hamming_ooblayout_ecc,
+        .free = brcmnand_hamming_ooblayout_free,
+};
+
+static int brcmnand_bch_ooblayout_ecc(struct mtd_info *mtd, int section,
+                                      struct mtd_oob_region *oobregion)
+{
+        struct nand_chip *chip = mtd_to_nand(mtd);
+        struct brcmnand_host *host = nand_get_controller_data(chip);
+        struct brcmnand_cfg *cfg = &host->hwcfg;
+        int sas = cfg->spare_area_size << cfg->sector_size_1k;
+        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
+
+        if (section >= sectors)
+                return -ERANGE;
+
+        oobregion->offset = (section * (sas + 1)) - chip->ecc.bytes;
+        oobregion->length = chip->ecc.bytes;
+
+        return 0;
 }
 
-static struct nand_ecclayout *brcmstb_choose_ecc_layout(
-                struct brcmnand_host *host)
+static int brcmnand_bch_ooblayout_free_lp(struct mtd_info *mtd, int section,
+                                          struct mtd_oob_region *oobregion)
+{
+        struct nand_chip *chip = mtd_to_nand(mtd);
+        struct brcmnand_host *host = nand_get_controller_data(chip);
+        struct brcmnand_cfg *cfg = &host->hwcfg;
+        int sas = cfg->spare_area_size << cfg->sector_size_1k;
+        int sectors = cfg->page_size / (512 << cfg->sector_size_1k);
+
+        if (section >= sectors)
+                return -ERANGE;
+
+        if (sas <= chip->ecc.bytes)
+                return 0;
+
+        oobregion->offset = section * sas;
+        oobregion->length = sas - chip->ecc.bytes;
+
+        if (!section) {
+                oobregion->offset++;
+                oobregion->length--;
+        }
+
+        return 0;
+}
+
+static int brcmnand_bch_ooblayout_free_sp(struct mtd_info *mtd, int section,
+                                          struct mtd_oob_region *oobregion)
+{
+        struct nand_chip *chip = mtd_to_nand(mtd);
+        struct brcmnand_host *host = nand_get_controller_data(chip);
+        struct brcmnand_cfg *cfg = &host->hwcfg;
+        int sas = cfg->spare_area_size << cfg->sector_size_1k;
+
+        if (section > 1 || sas - chip->ecc.bytes < 6 ||
+            (section && sas - chip->ecc.bytes == 6))
+                return -ERANGE;
+
+        if (!section) {
+                oobregion->offset = 0;
+                oobregion->length = 5;
+        } else {
+                oobregion->offset = 6;
+                oobregion->length = sas - chip->ecc.bytes - 6;
+        }
+
+        return 0;
+}
+
+static const struct mtd_ooblayout_ops brcmnand_bch_lp_ooblayout_ops = {
+        .ecc = brcmnand_bch_ooblayout_ecc,
+        .free = brcmnand_bch_ooblayout_free_lp,
+};
+
+static const struct mtd_ooblayout_ops brcmnand_bch_sp_ooblayout_ops = {
+        .ecc = brcmnand_bch_ooblayout_ecc,
+        .free = brcmnand_bch_ooblayout_free_sp,
+};
+
+static int brcmstb_choose_ecc_layout(struct brcmnand_host *host)
 {
-        struct nand_ecclayout *layout;
         struct brcmnand_cfg *p = &host->hwcfg;
+        struct mtd_info *mtd = nand_to_mtd(&host->chip);
+        struct nand_ecc_ctrl *ecc = &host->chip.ecc;
         unsigned int ecc_level = p->ecc_level;
+        int sas = p->spare_area_size << p->sector_size_1k;
+        int sectors = p->page_size / (512 << p->sector_size_1k);
 
         if (p->sector_size_1k)
                 ecc_level <<= 1;
 
-        layout = brcmnand_create_layout(ecc_level, host);
-        if (!layout) {
+        if (is_hamming_ecc(p)) {
+                ecc->bytes = 3 * sectors;
+                mtd_set_ooblayout(mtd, &brcmnand_hamming_ooblayout_ops);
+                return 0;
+        }
+
+        /*
+         * CONTROLLER_VERSION:
+         *   < v5.0: ECC_REQ = ceil(BCH_T * 13/8)
+         *  >= v5.0: ECC_REQ = ceil(BCH_T * 14/8)
+         * But we will just be conservative.
+         */
+        ecc->bytes = DIV_ROUND_UP(ecc_level * 14, 8);
+        if (p->page_size == 512)
+                mtd_set_ooblayout(mtd, &brcmnand_bch_sp_ooblayout_ops);
+        else
+                mtd_set_ooblayout(mtd, &brcmnand_bch_lp_ooblayout_ops);
+
+        if (ecc->bytes >= sas) {
                 dev_err(&host->pdev->dev,
-                                "no proper ecc_layout for this NAND cfg\n");
-                return NULL;
+                        "error: ECC too large for OOB (ECC bytes %d, spare sector %d)\n",
+                        ecc->bytes, sas);
+                return -EINVAL;
         }
 
-        return layout;
+        return 0;
 }
 
 static void brcmnand_wp(struct mtd_info *mtd, int wp)
@@ -2010,9 +2066,9 @@ static int brcmnand_init_cs(struct brcmnand_host *host, struct device_node *dn)
         /* only use our internal HW threshold */
         mtd->bitflip_threshold = 1;
 
-        chip->ecc.layout = brcmstb_choose_ecc_layout(host);
-        if (!chip->ecc.layout)
-                return -ENXIO;
+        ret = brcmstb_choose_ecc_layout(host);
+        if (ret)
+                return ret;
 
         if (nand_scan_tail(mtd))
                 return -ENXIO;