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SubjectRe: [PATCH 3/4] mtd: spi-nor: Add Octal 8D-8D-8D mode support for Macronix mx25uw51245g
Date


On 15/11/19 2:28 pm, Mason Yang wrote:
> mx25uw51245g is a SPI NOR that supports 1-1-1/8-8-8 mode and the SFDPRD
> command but returns an empty SFDP page. This forces us to add a new entry
> in the flash_info table and patch spi_nor_fixups hooks to tweak flash
> parameters for spi_nor_read/pp_setting() and then to enter
> Octal 8D-8D-8D modes.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> ---
> drivers/mtd/spi-nor/spi-nor.c | 114 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/mtd/spi-nor.h | 3 ++
> 2 files changed, 117 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 4cdf52d..9013590 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -615,6 +615,56 @@ static int write_disable(struct spi_nor *nor)
> }
>
> /*
> + * Read configuration register 2, returning its value in the
> + * location. Return the configuration register 2 value.
> + * Returns negative if error occurred.
> + */
> +static int read_cr2(struct spi_nor *nor, u32 addr)

Please prefix spi_nor_* for all new functions.
Also, include manf name if its vendor specific.

> +{
> + int ret;
> +
> + if (nor->spimem) {
> + struct spi_mem_op op =
> + SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_RDCR2, 1),
> + SPI_MEM_OP_ADDR(4, addr, 1),
> + SPI_MEM_OP_DUMMY(4, 1),
> + SPI_MEM_OP_DATA_IN(1, nor->bouncebuf, 1));
> +
> + if (spi_nor_protocol_is_8_8_8(nor->read_proto)) {
> + op.cmd.buswidth = 8;
> + op.addr.buswidth = 8;
> + op.dummy.buswidth = 8;
> + op.data.buswidth = 8;
> + op.cmd.nbytes = 2;
> +
> + if (spi_nor_protocol_is_8D_8D_8D(nor->read_proto)) {
> + op.dummy.nbytes *= 2;
> + op.cmd.dtr = true;
> + op.addr.dtr = true;
> + op.dummy.dtr = true;
> + op.data.dtr = true;
> + }
> +
> + if (nor->ext_cmd_mode == EXT_CMD_IS_INVERSE)
> + op.cmd.ext_opcode = ~SPINOR_OP_RDCR2;
> + else
> + op.cmd.ext_opcode = SPINOR_OP_RDCR2;
> + }
> +
> + ret = spi_mem_exec_op(nor->spimem, &op);
> + } else {
> + ret = -ENOTSUPP;
> + }
> +
> + if (ret < 0) {
> + dev_err(nor->dev, "error %d reading CR\n", ret);
> + return ret;
> + }
> +
> + return nor->bouncebuf[0];
> +}
> +
> +/*
> * Write configuration register 2 one byte
> * Returns negative if error occurred.
> */
> @@ -2275,10 +2325,72 @@ static int spi_nor_spansion_clear_sr_bp(struct spi_nor *nor)
> return 0;
> }
>
> +static void
> +spi_nor_set_read_settings(struct spi_nor_read_command *read,
> + u8 num_mode_clocks,
> + u8 num_wait_states,
> + u8 opcode,
> + enum spi_nor_protocol proto);
> +
> +static void
> +spi_nor_set_pp_settings(struct spi_nor_pp_command *pp,
> + u8 opcode,
> + enum spi_nor_protocol proto);
> +
> +static void
> +mx25uw51245g_default_init(struct spi_nor *nor)
> +{
> + struct spi_nor_flash_parameter *params = &nor->params;
> +
> + if (!(nor->spimem->spi->mode & (SPI_RX_OCTAL | SPI_TX_OCTAL)))
> + return;
> +
> + /* Octal 8S-8S-8S mode */
> + params->hwcaps.mask |= SNOR_HWCAPS_OPI_FULL_STR;
> + spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_8_8_8],
> + 0, 20, SPINOR_OP_READ_8_8_8,
> + SNOR_PROTO_8_8_8);
> +
> + spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_8_8_8],
> + SPINOR_OP_PP_8_8_8, SNOR_PROTO_8_8_8);
> +
> + /* Octal 8D-8D-8D mode */
> + params->hwcaps.mask |= SNOR_HWCAPS_OPI_FULL_DTR;
> + spi_nor_set_read_settings(&params->reads[SNOR_CMD_READ_8D_8D_8D],
> + 0, 20, SPINOR_OP_READ_8D_8D_8D,
> + SNOR_PROTO_8_8_8_DTR);
> +
> + spi_nor_set_pp_settings(&params->page_programs[SNOR_CMD_PP_8D_8D_8D],
> + SPINOR_OP_PP_8D_8D_8D, SNOR_PROTO_8_8_8_DTR);
> +
> + nor->ext_cmd_mode = EXT_CMD_IS_INVERSE;
> +}

I don't see anything that is macronix specific here.. Can this be moved to
generic code with information parsed from SFDP table?

> +
> +static void
> +mx25uw51245g_post_sfdp_fixups(struct spi_nor *nor)
> +{
> + struct spi_nor_flash_parameter *params = &nor->params;
> + u8 cr2;
> +
> + cr2 = read_cr2(nor, CR2_REG0) & CR2_REG0_MODE_MASK;
> +
> + if (params->hwcaps.mask & SNOR_HWCAPS_OPI_FULL_DTR)
> + cr2 |= CR2_REG0_MODE_OPI_DTR;
> + else if (params->hwcaps.mask & SNOR_HWCAPS_OPI_FULL_STR)
> + cr2 |= CR2_REG0_MODE_OPI_STR;
> +
> + write_cr2(nor, CR2_REG0, cr2);
> +}
> +

I see this as a misuse of sfdp_fixups hook:

* @post_sfdp: called after SFDP has been parsed (is also called for SPI NORs
* that do not support RDSFDP). Typically used to tweak various
* parameters that could not be extracted by other means (i.e.
* when information provided by the SFDP/flash_info tables are
* incomplete or wrong).
*


This should only tweak options parsed by SFDP and not be used to
configure flash to a different mode. Please add a separate function
to do so. See https://patchwork.kernel.org/patch/10638085/

Also, I guess JESD216C provides a way to discover command sequence
to enter OPI mode?

> static struct spi_nor_fixups mx25l25635_fixups = {
> .post_bfpt = mx25l25635_post_bfpt_fixups,
> };
>
> +static struct spi_nor_fixups mx25uw51245g_fixups = {
> + .default_init = mx25uw51245g_default_init,
> + .post_sfdp = mx25uw51245g_post_sfdp_fixups,
> +};
> +
> static void gd25q256_default_init(struct spi_nor *nor)
> {
> /*
> @@ -2442,6 +2554,8 @@ static void gd25q256_default_init(struct spi_nor *nor)
> SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
> .fixups = &mx25l25635_fixups },
> { "mx25u25635f", INFO(0xc22539, 0, 64 * 1024, 512, SECT_4K | SPI_NOR_4B_OPCODES) },
> + { "mx25uw51245g", INFO(0xc2813a, 0, 64 * 1024, 1024, SECT_4K | SPI_NOR_4B_OPCODES)
> + .fixups = &mx25uw51245g_fixups},
> { "mx25v8035f", INFO(0xc22314, 0, 64 * 1024, 16,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> { "mx25l25655e", INFO(0xc22619, 0, 64 * 1024, 512, 0) },
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 2e720ca..3aa54dd 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -114,6 +114,9 @@
> /* Write CFG Reg 2 - defined in JEDEC JESD216C. */
> #define SPINOR_OP_WRCR2 0x72 /* Write configuration register 2 */
>
> +/* Used for Macronix flashes only */
> +#define SPINOR_OP_RDCR2 0x71 /* Read configuration register 2 */
> +
> /* Used for Macronix and Winbond flashes. */
> #define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */
> #define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */
>

--
Regards
Vignesh

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