Re: [PATCH v4 06/11] mtd: spi-nor: Parse BFPT to determine the 4-Byte Address Mode methods
From: Tudor Ambarus
Date: Wed Mar 29 2023 - 13:22:42 EST
On 3/22/23 06:40, Tudor Ambarus wrote:
> BFPT[DWORD(16)] defines the methods to enter and exit the 4-Byte Address
> Mode. Parse BFPT to determine the method. Will rename the methods with
> generic names in a further patch, to keep things trackable in this one.>
I forgot to update the commit message, will respin.
> Some regressions may be introduced by this patch, because the
> params->set_4byte_addr_mode method that was set either in
> spi_nor_init_default_params() or later overwritten in default_init() hooks,
> may now be overwritten with a different value based on the BFPT data. If
> that's the case, the fix is to introduce a post_bfpt fixup hook where one
> should fix the wrong BFPT info.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxx>
> ---
> drivers/mtd/spi-nor/sfdp.c | 11 +++++++++++
> drivers/mtd/spi-nor/sfdp.h | 28 ++++++++++++++++++++++++++++
> drivers/mtd/spi-nor/winbond.c | 11 ++++++++++-
> 3 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/spi-nor/sfdp.c b/drivers/mtd/spi-nor/sfdp.c
> index 298ab5e53a8c..63b2810cf75e 100644
> --- a/drivers/mtd/spi-nor/sfdp.c
> +++ b/drivers/mtd/spi-nor/sfdp.c
> @@ -438,6 +438,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> size_t len;
> int i, cmd, err;
> u32 addr, val;
> + u32 dword;
> u16 half;
> u8 erase_mask;
>
> @@ -607,6 +608,16 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
> break;
> }
>
> + dword = bfpt.dwords[SFDP_DWORD(16)] & BFPT_DWORD16_4B_ADDR_MODE_MASK;
> + if (sfdp_bits_set(dword, BFPT_DWORD16_4B_ADDR_MODE_BRWR))
> + params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode_brwr;
> + else if (sfdp_bits_set(dword, BFPT_DWORD16_4B_ADDR_MODE_WREN_EN4B_EX4B))
> + params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode_wren_en4b_ex4b;
> + else if (sfdp_bits_set(dword, BFPT_DWORD16_4B_ADDR_MODE_EN4B_EX4B))
> + params->set_4byte_addr_mode = spi_nor_set_4byte_addr_mode_en4b_ex4b;
> + else
> + dev_dbg(nor->dev, "BFPT: 4-Byte Address Mode method is not recognized or not implemented\n");
> +
> /* Soft Reset support. */
> if (bfpt.dwords[SFDP_DWORD(16)] & BFPT_DWORD16_SWRST_EN_RST)
> nor->flags |= SNOR_F_SOFT_RESET;
> diff --git a/drivers/mtd/spi-nor/sfdp.h b/drivers/mtd/spi-nor/sfdp.h
> index 500659b35655..a4b5fe795f18 100644
> --- a/drivers/mtd/spi-nor/sfdp.h
> +++ b/drivers/mtd/spi-nor/sfdp.h
> @@ -16,6 +16,8 @@
> /* SFDP DWORDS are indexed from 1 but C arrays are indexed from 0. */
> #define SFDP_DWORD(i) ((i) - 1)
>
> +#define sfdp_bits_set(dword, mask) (((dword) & (mask)) == (mask))
s/sfdp_bits_set/sfdp_mask_check> +
> /* Basic Flash Parameter Table */
>
> /* JESD216 rev D defines a Basic Flash Parameter Table of 20 DWORDs. */
> @@ -89,6 +91,32 @@ struct sfdp_bfpt {
> #define BFPT_DWORD15_QER_SR2_BIT1_NO_RD (0x4UL << 20)
> #define BFPT_DWORD15_QER_SR2_BIT1 (0x5UL << 20) /* Spansion */
>
> +#define BFPT_DWORD16_EN4B_MASK GENMASK(31, 24)
> +#define BFPT_DWORD16_EN4B_ALWAYS_4B BIT(30)
> +#define BFPT_DWORD16_EN4B_4B_OPCODES BIT(29)
> +#define BFPT_DWORD16_EN4B_16BIT_NV_CR BIT(28)
> +#define BFPT_DWORD16_EN4B_BRWR BIT(27)
> +#define BFPT_DWORD16_EN4B_WREAR BIT(26)
> +#define BFPT_DWORD16_EN4B_WREN_EN4B BIT(25)
> +#define BFPT_DWORD16_EN4B_EN4B BIT(24)
> +#define BFPT_DWORD16_EX4B_MASK GENMASK(18, 14)
> +#define BFPT_DWORD16_EX4B_16BIT_NV_CR BIT(18)
> +#define BFPT_DWORD16_EX4B_BRWR BIT(17)
> +#define BFPT_DWORD16_EX4B_WREAR BIT(16)
> +#define BFPT_DWORD16_EX4B_WREN_EX4B BIT(15)
> +#define BFPT_DWORD16_EX4B_EX4B BIT(14)
> +#define BFPT_DWORD16_4B_ADDR_MODE_MASK \
> + (BFPT_DWORD16_EN4B_MASK | BFPT_DWORD16_EX4B_MASK)
> +#define BFPT_DWORD16_4B_ADDR_MODE_16BIT_NV_CR \
> + (BFPT_DWORD16_EN4B_16BIT_NV_CR | BFPT_DWORD16_EX4B_16BIT_NV_CR)
> +#define BFPT_DWORD16_4B_ADDR_MODE_BRWR \
> + (BFPT_DWORD16_EN4B_BRWR | BFPT_DWORD16_EX4B_BRWR)
> +#define BFPT_DWORD16_4B_ADDR_MODE_WREAR \
> + (BFPT_DWORD16_EN4B_WREAR | BFPT_DWORD16_EX4B_WREAR)
> +#define BFPT_DWORD16_4B_ADDR_MODE_WREN_EN4B_EX4B \
> + (BFPT_DWORD16_EN4B_WREN_EN4B | BFPT_DWORD16_EX4B_WREN_EX4B)
> +#define BFPT_DWORD16_4B_ADDR_MODE_EN4B_EX4B \
> + (BFPT_DWORD16_EN4B_EN4B | BFPT_DWORD16_EX4B_EX4B)
> #define BFPT_DWORD16_SWRST_EN_RST BIT(12)
>
> #define BFPT_DWORD18_CMD_EXT_MASK GENMASK(30, 29)
> diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
> index 9cea241c204b..a1b387accc07 100644
> --- a/drivers/mtd/spi-nor/winbond.c
> +++ b/drivers/mtd/spi-nor/winbond.c
> @@ -218,13 +218,22 @@ static const struct spi_nor_otp_ops winbond_nor_otp_ops = {
>
> static void winbond_nor_default_init(struct spi_nor *nor)
> {
> - nor->params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
> }
I should have got ridden of default_init entirely, it's now an empty
function.
>
> static void winbond_nor_late_init(struct spi_nor *nor)
> {
> if (nor->params->otp.org->n_regions)
> nor->params->otp.ops = &winbond_nor_otp_ops;
> +
> + /*
> + * Winbond seems to require that the Extended Address Register to be set
> + * to zero when exiting the 4-Byte Address Mode, at least for W25Q256FV.
> + * This requirement is not described in the JESD216 SFDP standard, thus
> + * it is Winbond specific. Since we do not know if other Winbond flashes
> + * have the same requirement, play safe and overwrite the method parsed
> + * from BFPT, if any.
> + */
> + nor->params->set_4byte_addr_mode = winbond_nor_set_4byte_addr_mode;
> }
>
> static const struct spi_nor_fixups winbond_nor_fixups = {