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

Michael Nazzareno Trimarchi michael at amarulasolutions.com
Mon Aug 26 12:42:03 CEST 2024


Hi

On Mon, Aug 26, 2024 at 11:00 AM Arseniy Krasnov
<avkrasnov at salutedevices.com> wrote:
>
>
>
> On 26.08.2024 10:16, Michael Nazzareno Trimarchi wrote:
> > 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?
>
> Idea is the following IIUC: such boot pages could be read in ECC mode only with enabled scrambling -
> otherwise we get ECC error. Or we need to read it in raw mode. So:
>
> if (read page in raw mode) {
>     use scrambler as provided
> } else if (read boot page in ECC mode) {
>     force scrambling mode + NFC_ECC_BCH8_1K + NFC_CMD_SHORTMODE_ENABLE
> } else {
>     //we read non-boot page in ECC mode
>    use scrambler as provided
> }
>
> Thanks
>
>
> >
> > 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
> >>
> >
> >

The first patch seems not apply clean to me on master

Reviewed-by: Michael Trimarchi <michael at amarulasolutions.com>



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

Amarula Solutions BV
Joop Geesinkweg 125, 1114 AB, Amsterdam, NL
T. +31 (0)85 111 9172
info at amarulasolutions.com
www.amarulasolutions.com


More information about the U-Boot mailing list