[PATCH v2 3/3] mtd: rawnand: meson: read/write access for boot ROM pages

[Michael Nazzareno Trimarchi]

Hi

On Mon, Aug 26, 2024 at 8:17 AM Arseniy Krasnov
<avkrasnov at salutedevices.com> wrote:
>
> Boot ROM on Meson needs some pages to be read/written in a special mode:
> 384 byte ECC mode (so called "short" by Amlogic) and with scrambling
> enabled. Such pages are located on the chip in the following way (for
> example):
>
> [ p0 ][ p1 ][ p2 ][ p3 ][ p4 ][ p5 ][ p6 ][ p7 ] ... [ pN ]
>   ^           ^           ^           ^
>
> pX is page number "X". "^" means "special" page used by boot ROM - e.g.
> every 2nd page in the range of [0, 7]. Step (2 here) and last page in
> range is read from the device tree.
>
> Signed-off-by: Arseniy Krasnov <avkrasnov at salutedevices.com>
> ---
>  drivers/mtd/nand/raw/meson_nand.c | 56 +++++++++++++++++++++++++------
>  1 file changed, 46 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index 19f005202b..54ea035d8d 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -40,6 +40,7 @@
>  #define NFC_CMD_RB                     BIT(20)
>  #define NFC_CMD_SCRAMBLER_ENABLE       BIT(19)
>  #define NFC_CMD_SCRAMBLER_DISABLE      0
> +#define NFC_CMD_SHORTMODE_ENABLE       1
>  #define NFC_CMD_SHORTMODE_DISABLE      0
>  #define NFC_CMD_RB_INT                 BIT(14)
>  #define NFC_CMD_RB_INT_NO_PIN          ((0xb << 10) | BIT(18) | BIT(16))
> @@ -78,6 +79,8 @@
>
>  #define DMA_DIR(dir)           ((dir) ? NFC_CMD_N2M : NFC_CMD_M2N)
>
> +#define NFC_SHORT_MODE_ECC_SZ  384
> +
>  #define ECC_CHECK_RETURN_FF    -1
>
>  #define NAND_CE0               (0xe << 10)
> @@ -141,6 +144,8 @@
>  struct meson_nfc_nand_chip {
>         struct list_head node;
>         struct nand_chip nand;
> +       u32 boot_pages;
> +       u32 boot_page_step;
>
>         u32 bch_mode;
>         u8 *data_buf;
> @@ -229,33 +234,46 @@ static void meson_nfc_cmd_seed(const struct meson_nfc *nfc, u32 seed)
>                nfc->reg_base + NFC_REG_CMD);
>  }
>
> +static int meson_nfc_is_boot_page(struct nand_chip *nand, int page)
> +{
> +       const struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> +
> +       return (nand->options & NAND_IS_BOOT_MEDIUM) &&
> +              !(page % meson_chip->boot_page_step) &&
> +              (page < meson_chip->boot_pages);
> +}
> +
>  static void meson_nfc_cmd_access(struct nand_chip *nand, bool raw, bool dir, int page)
>  {
> +       const struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>         struct mtd_info *mtd = nand_to_mtd(nand);
>         const struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
> -       const struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> -       u32 bch = meson_chip->bch_mode, cmd;
>         int len = mtd->writesize, pagesize, pages;
>         int scrambler;
> +       u32 cmd;
>
>         if (nand->options & NAND_NEED_SCRAMBLING)
>                 scrambler = NFC_CMD_SCRAMBLER_ENABLE;
>         else
>                 scrambler = NFC_CMD_SCRAMBLER_DISABLE;
>

scrambler depends on NAND_NEED_SCRAMBLING so suppose
that is not set

scrambler = NAND_NEED_SCRAMBLING;

> -       pagesize = nand->ecc.size;
> -
>         if (raw) {
>                 len = mtd->writesize + mtd->oobsize;
>                 cmd = len | scrambler | DMA_DIR(dir);
> -               writel(cmd, nfc->reg_base + NFC_REG_CMD);
> -               return;
> -       }
> +       } else if (meson_nfc_is_boot_page(nand, page)) {

Now here you  seems that you don't care anymore about this option and check
only meson_nfc_is_boot_page

Is something am I missing?

Michael

> +               pagesize = NFC_SHORT_MODE_ECC_SZ >> 3;
> +               pages = mtd->writesize / 512;
>
> -       pages = len / nand->ecc.size;
> +               scrambler = NFC_CMD_SCRAMBLER_ENABLE;
> +               cmd = CMDRWGEN(DMA_DIR(dir), scrambler, NFC_ECC_BCH8_1K,
> +                              NFC_CMD_SHORTMODE_ENABLE, pagesize, pages);
> +       } else {
> +               pagesize = nand->ecc.size >> 3;
> +               pages = len / nand->ecc.size;
>
> -       cmd = CMDRWGEN(DMA_DIR(dir), scrambler, bch,
> -                      NFC_CMD_SHORTMODE_DISABLE, pagesize, pages);
> +               cmd = CMDRWGEN(DMA_DIR(dir), scrambler, meson_chip->bch_mode,
> +                              NFC_CMD_SHORTMODE_DISABLE, pagesize, pages);
> +       }
>
>         if (scrambler == NFC_CMD_SCRAMBLER_ENABLE)
>                 meson_nfc_cmd_seed(nfc, page);
> @@ -1132,6 +1150,24 @@ static int meson_nfc_nand_chip_init(struct udevice *dev, struct meson_nfc *nfc,
>                 goto err_chip_buf_free;
>         }
>
> +       if (nand->options & NAND_IS_BOOT_MEDIUM) {
> +               ret = ofnode_read_u32(node, "amlogic,boot-pages",
> +                                     &meson_chip->boot_pages);
> +               if (ret) {
> +                       dev_err(dev, "could not retrieve 'amlogic,boot-pages' property: %d",
> +                               ret);
> +                       goto err_chip_buf_free;
> +               }
> +
> +               ret = ofnode_read_u32(node, "amlogic,boot-page-step",
> +                                     &meson_chip->boot_page_step);
> +               if (ret) {
> +                       dev_err(dev, "could not retrieve 'amlogic,boot-page-step' property: %d",
> +                               ret);
> +                       goto err_chip_buf_free;
> +               }
> +       }
> +
>         ret = nand_register(0, mtd);
>         if (ret) {
>                 dev_err(dev, "'nand_register()' failed: %d\n", ret);
> --
> 2.30.1
>


-- 
Michael Nazzareno Trimarchi
Co-Founder & Chief Executive Officer
M. +39 347 913 2170
michael at amarulasolutions.com
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