Commit 04a81b4f authored by Arseniy Krasnov's avatar Arseniy Krasnov Committed by Miquel Raynal
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mtd: rawnand: meson: read/write access for boot ROM pages 



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: default avatarArseniy Krasnov <avkrasnov@salutedevices.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240507230903.3399594-4-avkrasnov@salutedevices.com
parent 2234585f

drivers/mtd/nand/raw/meson_nand.c

+48 −10
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#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 DMA_ADDR_ALIGN		8



#define NFC_SHORT_MODE_ECC_SZ	384



#define ECC_CHECK_RETURN_FF	(-1)



#define NAND_CE0		(0xe << 10)
@@ -125,6 +128,8 @@ struct meson_nfc_nand_chip { 
	u32 twb;

	u32 tadl;

	u32 tbers_max;

	u32 boot_pages;

	u32 boot_page_step;



	u32 bch_mode;

	u8 *data_buf;
@@ -298,33 +303,46 @@ static void meson_nfc_cmd_seed(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, int 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);

	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));

	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;



	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)) {

		pagesize = NFC_SHORT_MODE_ECC_SZ >> 3;

		pages = mtd->writesize / 512;



		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,

		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);
@@ -1425,6 +1443,26 @@ meson_nfc_nand_chip_init(struct device *dev, 
	if (ret)

		return ret;



	if (nand->options & NAND_IS_BOOT_MEDIUM) {

		ret = of_property_read_u32(np, "amlogic,boot-pages",

					   &meson_chip->boot_pages);

		if (ret) {

			dev_err(dev, "could not retrieve 'amlogic,boot-pages' property: %d",

				ret);

			nand_cleanup(nand);

			return ret;

		}



		ret = of_property_read_u32(np, "amlogic,boot-page-step",

					   &meson_chip->boot_page_step);

		if (ret) {

			dev_err(dev, "could not retrieve 'amlogic,boot-page-step' property: %d",

				ret);

			nand_cleanup(nand);

			return ret;

		}

	}



	ret = mtd_device_register(mtd, NULL, 0);

	if (ret) {

		dev_err(dev, "failed to register MTD device: %d\n", ret);