mtd: nand: raw: rockchip_nfc: copy hwecc PA data to oob_poi buffer

Rockchip boot blocks are written per 4 x 512 byte sectors per page.
Each page must have a page address (PA) pointer in OOB to the next page.
Pages are written in a pattern depending on the NAND chip ID.
This logic used to build a page pattern table is not fully disclosed and
is not easy to fit in the MTD framework.
The formula in rk_nfc_write_page_hwecc() function is not correct.
Make hwecc and raw behavior identical.
Generate boot block page address and pattern for hwecc in user space
and copy PA data to/from the already reserved last 4 bytes before EEC
in the chip->oob_poi data layout.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

diff --git a/drivers/mtd/nand/raw/rockchip_nfc.c b/drivers/mtd/nand/raw/rockchip_nfc.c
index 5fcf6a6..274489e 100644 (file)
--- a/drivers/mtd/nand/raw/rockchip_nfc.c
+++ b/drivers/mtd/nand/raw/rockchip_nfc.c
@@ -525,7 +525,7 @@ static int rk_nfc_write_page_hwecc(struct mtd_info *mtd,
        int pages_per_blk = mtd->erasesize / mtd->writesize;
        int ret = 0, i, boot_rom_mode = 0;
        dma_addr_t dma_data, dma_oob;
-       u32 reg;
+       u32 tmp;
        u8 *oob;
 
        nand_prog_page_begin_op(chip, page, 0, NULL, 0);
@@ -552,6 +552,13 @@ static int rk_nfc_write_page_hwecc(struct mtd_info *mtd,
         *
         *   0xFF 0xFF 0xFF 0xFF | BBM OOB1 OOB2 OOB3 | ...
         *
+        * The code here just swaps the first 4 bytes with the last
+        * 4 bytes without losing any data.
+        *
+        * The chip->oob_poi data layout:
+        *
+        *    BBM  OOB1 OOB2 OOB3 |......|  PA0  PA1  PA2  PA3
+        *
         * Configure the ECC algorithm supported by the boot ROM.
         */
        if (page < (pages_per_blk * rknand->boot_blks)) {
@@ -561,21 +568,17 @@ static int rk_nfc_write_page_hwecc(struct mtd_info *mtd,
        }
 
        for (i = 0; i < ecc->steps; i++) {
-               if (!i) {
-                       reg = 0xFFFFFFFF;
-               } else {
+               if (!i)
+                       oob = chip->oob_poi + (ecc->steps - 1) * NFC_SYS_DATA_SIZE;
+               else
                        oob = chip->oob_poi + (i - 1) * NFC_SYS_DATA_SIZE;
-                       reg = oob[0] | oob[1] << 8 | oob[2] << 16 |
-                             oob[3] << 24;
-               }
 
-               if (!i && boot_rom_mode)
-                       reg = (page & (pages_per_blk - 1)) * 4;
+               tmp = oob[0] | oob[1] << 8 | oob[2] << 16 | oob[3] << 24;
 
                if (nfc->cfg->type == NFC_V9)
-                       nfc->oob_buf[i] = reg;
+                       nfc->oob_buf[i] = tmp;
                else
-                       nfc->oob_buf[i * (oob_step / 4)] = reg;
+                       nfc->oob_buf[i * (oob_step / 4)] = tmp;
        }
 
        dma_data = dma_map_single((void *)nfc->page_buf,
@@ -720,12 +723,17 @@ static int rk_nfc_read_page_hwecc(struct mtd_info *mtd,
                goto timeout_err;
        }
 
-       for (i = 1; i < ecc->steps; i++) {
-               oob = chip->oob_poi + (i - 1) * NFC_SYS_DATA_SIZE;
+       for (i = 0; i < ecc->steps; i++) {
+               if (!i)
+                       oob = chip->oob_poi + (ecc->steps - 1) * NFC_SYS_DATA_SIZE;
+               else
+                       oob = chip->oob_poi + (i - 1) * NFC_SYS_DATA_SIZE;
+
                if (nfc->cfg->type == NFC_V9)
                        tmp = nfc->oob_buf[i];
                else
                        tmp = nfc->oob_buf[i * (oob_step / 4)];
+
                *oob++ = (u8)tmp;
                *oob++ = (u8)(tmp >> 8);
                *oob++ = (u8)(tmp >> 16);