[PATCH v2 3/3] mtd: rawnand: meson: read/write access for boot ROM pages
Arseniy Krasnov
avkrasnov at salutedevices.com
Mon Aug 26 14:20:40 CEST 2024
On 26.08.2024 13:42, Michael Nazzareno Trimarchi wrote:
> 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>
Got it, I'll check
Thanks
>
>
>
More information about the U-Boot
mailing list