[PATCH v6 1/4] mtd: spi-nor: macronix: add support for Macronix Octal
liao jaime
jaimeliao.tw at gmail.com
Thu Jan 6 02:57:18 CET 2022
Hi Tudor
>
> Hi,
>
> On 12/29/21 7:56 AM, JaimeLiao wrote:
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> >
> > Follow patch "f6adec1af4b2f5d3012480c6cdce7743b74a6156" for adding
> > Macronix flash in Octal DTR mode.
> >
> > Enable Octal DTR mode with 20 dummy cycles to allow running at the
> > maximum supported frequency.
> > -https://www.mxic.com.tw/Lists/Datasheet/Attachments/7841/MX25LM51245G,%203V,%20512Mb,%20v1.1.pdf
> >
> > Signed-off-by: JaimeLiao <jaimeliao.tw at gmail.com>
> > ---
> > drivers/mtd/spi/spi-nor-core.c | 83 ++++++++++++++++++++++++++++++++++
> > include/linux/mtd/spi-nor.h | 12 ++++-
> > 2 files changed, 93 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
> > index d5d905fa5a..0a6550984b 100644
> > --- a/drivers/mtd/spi/spi-nor-core.c
> > +++ b/drivers/mtd/spi/spi-nor-core.c
> > @@ -3489,6 +3489,85 @@ static struct spi_nor_fixups mt35xu512aba_fixups = {
> > };
> > #endif /* CONFIG_SPI_FLASH_MT35XU */
> >
> > +#if CONFIG_IS_ENABLED(SPI_FLASH_MACRONIX)
> > +/**
> > + * spi_nor_macronix_octal_dtr_enable() - set DTR OPI Enable bit in Configuration Register 2.
> > + * @nor: pointer to a 'struct spi_nor'
> > + *
> > + * Set the DTR OPI Enable (DOPI) bit in Configuration Register 2.
> > + * Bit 2 of Configuration Register 2 is the DOPI bit for Macronix like OPI memories.
> > + *
> > + * Return: 0 on success, -errno otherwise.
> > + */
> > +static int spi_nor_macronix_octal_dtr_enable(struct spi_nor *nor)
>
> This method should be called just for the flashes that do not define the
> JESD216 "Command Sequences to Change to Octal DDR (8D-8D-8D) mode" table.
> Or where SFDP is skipped intentionally.
I think Octal DTR enable method have been defined by manufacturers.
It would be better if the method could be parce from SFDP.
But I prefer to follow the existing rules for adding the flashes which
have been output but not be support in uboot.
>
> > +{
> > + struct spi_mem_op op;
> > + int ret;
> > + u8 buf;
> > +
> > + ret = write_enable(nor);
> > + if (ret)
> > + return ret;
> > +
> > + buf = SPINOR_REG_MXIC_DC_20;
> > + op = (struct spi_mem_op)
> > + SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_CR2, 1),
> > + SPI_MEM_OP_ADDR(4, SPINOR_REG_MXIC_CR2_DC, 1),
> > + SPI_MEM_OP_NO_DUMMY,
> > + SPI_MEM_OP_DATA_OUT(1, &buf, 1));
> > +
> > + ret = spi_mem_exec_op(nor->spi, &op);
> > + if (ret)
> > + return ret;
> > +
> > + ret = spi_nor_wait_till_ready(nor);
> > + if (ret)
> > + return ret;
> > +
> > + nor->read_dummy = MXIC_MAX_DC;
> > + ret = write_enable(nor);
> > + if (ret)
> > + return ret;
> > +
> > + buf = SPINOR_REG_MXIC_OPI_DTR_EN;
> > + op = (struct spi_mem_op)
> > + SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_WR_CR2, 1),
> > + SPI_MEM_OP_ADDR(4, SPINOR_REG_MXIC_CR2_MODE, 1),
> > + SPI_MEM_OP_NO_DUMMY,
> > + SPI_MEM_OP_DATA_OUT(1, &buf, 1));
> > +
> > + ret = spi_mem_exec_op(nor->spi, &op);
> > + if (ret) {
> > + dev_err(nor->dev, "Failed to enable octal DTR mode\n");
> > + return ret;
> > + }
> > + nor->reg_proto = SNOR_PROTO_8_8_8_DTR;
> > +
> > + return 0;
> > +}
> > +
> > +static void macronix_octal_default_init(struct spi_nor *nor)
>
> I think we should get rid of the default_init() hook, it messes how
> the params are initialized, there's a spaghetti right now, it's very hard to
> determine who initializes which params solely by reading the code. I would
> advise to follow linux and use a late_init() hook where explicit octal dtr
> enable method is required.
Sure it is a good idea.
I hope U-boot could have more similar architecture with Linux kernel.
>
>
> > +{
> > + nor->octal_dtr_enable = spi_nor_macronix_octal_dtr_enable;
> > +}
> > +
> > +static void macronix_octal_post_sfdp_fixup(struct spi_nor *nor,
> > + struct spi_nor_flash_parameter *params)
> > +{
> > + /*
> > + * Adding SNOR_HWCAPS_PP_8_8_8_DTR in hwcaps.mask when
> > + * SPI_NOR_OCTAL_DTR_READ flag exists.
> > + */
> > + if (params->hwcaps.mask & SNOR_HWCAPS_READ_8_8_8_DTR)
> > + params->hwcaps.mask |= SNOR_HWCAPS_PP_8_8_8_DTR;
>
> This confirms the spaghetti theory. This is not SFDP related, why do you use
> the post_sfdp hook?
Because of SPI_NOR_OCTAL_DTR_PP is not existing in U-boot.
I will take other suitable method to enable it next patch.
>
> > +}
> > +
> > +static struct spi_nor_fixups macronix_octal_fixups = {
> > + .default_init = macronix_octal_default_init,
> > + .post_sfdp = macronix_octal_post_sfdp_fixup,
> > +};
> > +#endif /* CONFIG_SPI_FLASH_MACRONIX */
> > +
> > /** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed
> > * @nor: pointer to a 'struct spi_nor'
> > *
> > @@ -3655,6 +3734,10 @@ void spi_nor_set_fixups(struct spi_nor *nor)
> > if (!strcmp(nor->info->name, "mt35xu512aba"))
> > nor->fixups = &mt35xu512aba_fixups;
> > #endif
> > +
> > +#if CONFIG_IS_ENABLED(SPI_FLASH_MACRONIX)
> Not related to your patch, but ideally all the macronix code should reside
> in a dedicated macronix.c driver.
Sure, but all manufacturer IDs are gather in spi-nor-ids.c now.
>
> Cheers,
> ta
>
> > + nor->fixups = ¯onix_octal_fixups;
> > +#endif /* SPI_FLASH_MACRONIX */
> > }
> >
> > int spi_nor_scan(struct spi_nor *nor)
> > diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> > index 7ddc4ba2bf..8682368f2f 100644
> > --- a/include/linux/mtd/spi-nor.h
> > +++ b/include/linux/mtd/spi-nor.h
> > @@ -116,8 +116,16 @@
> > #define XSR_RDY BIT(7) /* Ready */
> >
> > /* Used for Macronix and Winbond flashes. */
> > -#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
> > -#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
> > +#define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
> > +#define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
> > +#define SPINOR_OP_RD_CR2 0x71 /* Read configuration register 2 */
> > +#define SPINOR_OP_WR_CR2 0x72 /* Write configuration register 2 */
> > +#define SPINOR_OP_MXIC_DTR_RD 0xee /* Fast Read opcode in DTR mode */
> > +#define SPINOR_REG_MXIC_CR2_MODE 0x00000000 /* For setting octal DTR mode */
> > +#define SPINOR_REG_MXIC_OPI_DTR_EN 0x2 /* Enable Octal DTR */
> > +#define SPINOR_REG_MXIC_CR2_DC 0x00000300 /* For setting dummy cycles */
> > +#define SPINOR_REG_MXIC_DC_20 0x0 /* Setting dummy cycles to 20 */
> > +#define MXIC_MAX_DC 20 /* Maximum value of dummy cycles */
> >
> > /* Used for Spansion flashes only. */
> > #define SPINOR_OP_BRWR 0x17 /* Bank register write */
> > --
> > 2.17.1
> >
>
Thanks
Jaime
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