[PATCH v2 1/5] mtd: nand: raw: rockchip-nand-controller: copy hwecc PA data to oob_poi buffer

Johan Jonker
2023-06-12T15:03:15Z

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 last 4 bytes in the
chip->oob_poi data layout.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
---
.../mtd/nand/raw/rockchip-nand-controller.c | 34 ++++++++++++-------
1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/mtd/nand/raw/rockchip-nand-controller.c b/drivers/mtd/nand/raw/rockchip-nand-controller.c
index 2312e2736..cafccc324 100644
--- a/drivers/mtd/nand/raw/rockchip-nand-controller.c
+++ b/drivers/mtd/nand/raw/rockchip-nand-controller.c
@@ -597,7 +597,7 @@ static int rk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
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);
@@ -624,6 +624,13 @@ static int rk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
*
* 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)) &&
@@ -634,21 +641,17 @@ static int rk_nfc_write_page_hwecc(struct nand_chip *chip, const u8 *buf,
}

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(nfc->dev, (void *)nfc->page_buf,
@@ -811,12 +814,17 @@ static int rk_nfc_read_page_hwecc(struct nand_chip *chip, u8 *buf, int oob_on,
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);