mtd: nand: omap_gpmc: Fix NAND in SPL for AM335x

AM335x uses a special driver "am335x_spl_bch.c" as SPL
NAND loader. This driver expects 1 sector at a time ECC
and doesn't work well with multi-sector ECC that was implemented
in commit 04fcd2587321.

Switch back to 1 sector at a time read/ECC.

Fixes: 04fcd2587321 ("mtd: rawnand: omap_gpmc: Fix BCH6/16 HW based correction")
Signed-off-by: Roger Quadros <rogerq@kernel.org>

1 files changed, 30 insertions, 66 deletions

diff --git a/drivers/mtd/nand/raw/omap_gpmc.c b/drivers/mtd/nand/raw/omap_gpmc.c
index 43f7363b9dd..fc8383d84b4 100644
--- a/drivers/mtd/nand/raw/omap_gpmc.c
+++ b/drivers/mtd/nand/raw/omap_gpmc.c
@@ -293,7 +293,7 @@ static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd,
                 break;
         case OMAP_ECC_BCH8_CODE_HW:
                 bch_type = 1;
-                nsectors = chip->ecc.steps;
+                nsectors = 1;
                 if (mode == NAND_ECC_READ) {
                         wr_mode   = BCH_WRAPMODE_1;
                         ecc_size0 = BCH8R_ECC_SIZE0;
@@ -306,7 +306,7 @@ static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd,
                 break;
         case OMAP_ECC_BCH16_CODE_HW:
                 bch_type = 0x2;
-                nsectors = chip->ecc.steps;
+                nsectors = 1;
                 if (mode == NAND_ECC_READ) {
                         wr_mode   = 0x01;
                         ecc_size0 = 52; /* ECC bits in nibbles per sector */
@@ -345,17 +345,16 @@ static void __maybe_unused omap_enable_hwecc_bch(struct mtd_info *mtd,
 }
 
 /**
- * _omap_calculate_ecc_bch - Generate BCH ECC bytes for one sector
+ * omap_calculate_ecc_bch - Generate BCH ECC bytes for one sector
  * @mtd:        MTD device structure
  * @dat:        The pointer to data on which ecc is computed
  * @ecc_code:   The ecc_code buffer
- * @sector:     The sector number (for a multi sector page)
  *
  * Support calculating of BCH4/8/16 ECC vectors for one sector
  * within a page. Sector number is in @sector.
  */
-static int _omap_calculate_ecc_bch(struct mtd_info *mtd, const u8 *dat,
-                                   u8 *ecc_code, int sector)
+static int omap_calculate_ecc_bch(struct mtd_info *mtd, const u8 *dat,
+                                  u8 *ecc_code)
 {
         struct nand_chip *chip = mtd_to_nand(mtd);
         struct omap_nand_info *info = nand_get_controller_data(chip);
@@ -368,7 +367,7 @@ static int _omap_calculate_ecc_bch(struct mtd_info *mtd, const u8 *dat,
         case OMAP_ECC_BCH8_CODE_HW_DETECTION_SW:
 #endif
         case OMAP_ECC_BCH8_CODE_HW:
-                ptr = &gpmc_cfg->bch_result_0_3[sector].bch_result_x[3];
+                ptr = &gpmc_cfg->bch_result_0_3[0].bch_result_x[3];
                 val = readl(ptr);
                 ecc_code[i++] = (val >>  0) & 0xFF;
                 ptr--;
@@ -383,21 +382,21 @@ static int _omap_calculate_ecc_bch(struct mtd_info *mtd, const u8 *dat,
 
                 break;
         case OMAP_ECC_BCH16_CODE_HW:
-                val = readl(&gpmc_cfg->bch_result_4_6[sector].bch_result_x[2]);
+                val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[2]);
                 ecc_code[i++] = (val >>  8) & 0xFF;
                 ecc_code[i++] = (val >>  0) & 0xFF;
-                val = readl(&gpmc_cfg->bch_result_4_6[sector].bch_result_x[1]);
+                val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[1]);
                 ecc_code[i++] = (val >> 24) & 0xFF;
                 ecc_code[i++] = (val >> 16) & 0xFF;
                 ecc_code[i++] = (val >>  8) & 0xFF;
                 ecc_code[i++] = (val >>  0) & 0xFF;
-                val = readl(&gpmc_cfg->bch_result_4_6[sector].bch_result_x[0]);
+                val = readl(&gpmc_cfg->bch_result_4_6[0].bch_result_x[0]);
                 ecc_code[i++] = (val >> 24) & 0xFF;
                 ecc_code[i++] = (val >> 16) & 0xFF;
                 ecc_code[i++] = (val >>  8) & 0xFF;
                 ecc_code[i++] = (val >>  0) & 0xFF;
                 for (j = 3; j >= 0; j--) {
-                        val = readl(&gpmc_cfg->bch_result_0_3[sector].bch_result_x[j]
+                        val = readl(&gpmc_cfg->bch_result_0_3[0].bch_result_x[j]
                                                                         );
                         ecc_code[i++] = (val >> 24) & 0xFF;
                         ecc_code[i++] = (val >> 16) & 0xFF;
@@ -431,22 +430,6 @@ static int _omap_calculate_ecc_bch(struct mtd_info *mtd, const u8 *dat,
         return 0;
 }
 
-/**
- * omap_calculate_ecc_bch - ECC generator for 1 sector
- * @mtd:        MTD device structure
- * @dat:        The pointer to data on which ecc is computed
- * @ecc_code:   The ecc_code buffer
- *
- * Support calculating of BCH4/8/16 ECC vectors for one sector. This is used
- * when SW based correction is required as ECC is required for one sector
- * at a time.
- */
-static int __maybe_unused omap_calculate_ecc_bch(struct mtd_info *mtd,
-                                  const u_char *dat, u_char *ecc_calc)
-{
-        return _omap_calculate_ecc_bch(mtd, dat, ecc_calc, 0);
-}
-
 static inline void omap_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 {
         struct nand_chip *chip = mtd_to_nand(mtd);
@@ -572,34 +555,6 @@ static void omap_nand_read_prefetch(struct mtd_info *mtd, uint8_t *buf, int len)
 
 #ifdef CONFIG_NAND_OMAP_ELM
 
-/**
- * omap_calculate_ecc_bch_multi - Generate ECC for multiple sectors
- * @mtd:        MTD device structure
- * @dat:        The pointer to data on which ecc is computed
- * @ecc_code:   The ecc_code buffer
- *
- * Support calculating of BCH4/8/16 ecc vectors for the entire page in one go.
- */
-static int omap_calculate_ecc_bch_multi(struct mtd_info *mtd,
-                                        const u_char *dat, u_char *ecc_calc)
-{
-        struct nand_chip *chip = mtd_to_nand(mtd);
-        int eccbytes = chip->ecc.bytes;
-        unsigned long nsectors;
-        int i, ret;
-
-        nsectors = ((readl(&gpmc_cfg->ecc_config) >> 4) & 0x7) + 1;
-        for (i = 0; i < nsectors; i++) {
-                ret = _omap_calculate_ecc_bch(mtd, dat, ecc_calc, i);
-                if (ret)
-                        return ret;
-
-                ecc_calc += eccbytes;
-        }
-
-        return 0;
-}
-
 /*
  * omap_reverse_list - re-orders list elements in reverse order [internal]
  * @list:       pointer to start of list
@@ -752,32 +707,38 @@ static int omap_read_page_bch(struct mtd_info *mtd, struct nand_chip *chip,
 {
         int i, eccsize = chip->ecc.size;
         int eccbytes = chip->ecc.bytes;
-        int ecctotal = chip->ecc.total;
         int eccsteps = chip->ecc.steps;
         uint8_t *p = buf;
         uint8_t *ecc_calc = chip->buffers->ecccalc;
         uint8_t *ecc_code = chip->buffers->ecccode;
         uint32_t *eccpos = chip->ecc.layout->eccpos;
         uint8_t *oob = chip->oob_poi;
+        uint32_t data_pos;
         uint32_t oob_pos;
 
+        data_pos = 0;
         /* oob area start */
         oob_pos = (eccsize * eccsteps) + chip->ecc.layout->eccpos[0];
         oob += chip->ecc.layout->eccpos[0];
 
-        /* Enable ECC engine */
-        chip->ecc.hwctl(mtd, NAND_ECC_READ);
+        for (i = 0; eccsteps; eccsteps--, i += eccbytes, p += eccsize,
+                                oob += eccbytes) {
+                /* Enable ECC engine */
+                chip->ecc.hwctl(mtd, NAND_ECC_READ);
 
-        /* read entire page */
-        chip->cmdfunc(mtd, NAND_CMD_RNDOUT, 0, -1);
-        chip->read_buf(mtd, buf, mtd->writesize);
+                /* read data */
+                chip->cmdfunc(mtd, NAND_CMD_RNDOUT, data_pos, -1);
+                chip->read_buf(mtd, p, eccsize);
 
-        /* read all ecc bytes from oob area */
-        chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1);
-        chip->read_buf(mtd, oob, ecctotal);
+                /* read respective ecc from oob area */
+                chip->cmdfunc(mtd, NAND_CMD_RNDOUT, oob_pos, -1);
+                chip->read_buf(mtd, oob, eccbytes);
+                /* read syndrome */
+                chip->ecc.calculate(mtd, p, &ecc_calc[i]);
 
-        /* Calculate ecc bytes */
-        omap_calculate_ecc_bch_multi(mtd, buf, ecc_calc);
+                data_pos += eccsize;
+                oob_pos += eccbytes;
+        }
 
         for (i = 0; i < chip->ecc.total; i++)
                 ecc_code[i] = chip->oob_poi[eccpos[i]];
@@ -945,6 +906,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand,
                 nand->ecc.hwctl         = omap_enable_hwecc_bch;
                 nand->ecc.correct       = omap_correct_data_bch_sw;
                 nand->ecc.calculate     = omap_calculate_ecc_bch;
+                nand->ecc.steps         = eccsteps;
                 /* define ecc-layout */
                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
                 ecclayout->eccpos[0]    = BADBLOCK_MARKER_LENGTH;
@@ -987,6 +949,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand,
                 nand->ecc.correct       = omap_correct_data_bch;
                 nand->ecc.calculate     = omap_calculate_ecc_bch;
                 nand->ecc.read_page     = omap_read_page_bch;
+                nand->ecc.steps         = eccsteps;
                 /* define ecc-layout */
                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
                 for (i = 0; i < ecclayout->eccbytes; i++)
@@ -1020,6 +983,7 @@ static int omap_select_ecc_scheme(struct nand_chip *nand,
                 nand->ecc.correct       = omap_correct_data_bch;
                 nand->ecc.calculate     = omap_calculate_ecc_bch;
                 nand->ecc.read_page     = omap_read_page_bch;
+                nand->ecc.steps         = eccsteps;
                 /* define ecc-layout */
                 ecclayout->eccbytes     = nand->ecc.bytes * eccsteps;
                 for (i = 0; i < ecclayout->eccbytes; i++)