XTX25F32B does not use octal mode and accepts soft reset, despite its SFDP tables. Soft reset at U-Boot exit seems to be required to write to /dev/mtd0 from flashrom in linux. Soft reset at U-Boot start seems to help booting from SPI (at least with the dts properties I'm using).

The first soft reset is done before the flash id is read and the fixups can be called, and v1 of this patch would now fail in Rock Pi 4 because of unsupported operation if tried with SNOR_PROTO_8_8_8_DTR. This was since commit 5752d6ae8daa ("spi: spi-mem: add spi_mem_dtr_supports_op()") by Pratyush Yadav.

So try a few modes until SNOR_PROTO_1_1_1 works and then remember the reset_proto. This tries to be useful for other boards, but I still don't know any other that needs it and what would work there.

Changes from v1:

- Generalization. First soft reset with SNOR_PROTO_8_8_8_DTR stopped working since the improvement by Pratyush Yadav. Instead of trying 8_8_8_DTR always at first reset, and force 1_1_1 once XTX25F32B is detected (so, for last reset) do a generic loop for any chip trying protocols until one is supported and starting by the 8_8_8_DTR protocol (the one previously used). This leverages the fixed supports_op() to take into account controller and device.

Signed-off-by: Xavier Drudis Ferran xdrudis@tinet.cat

Cc: Jagan Teki jagan@amarulasolutions.com Cc: Vignesh R vigneshr@ti.com --- drivers/mtd/spi/spi-nor-core.c | 98 ++++++++++++++++++++++++++++++---- include/linux/mtd/spi-nor.h | 5 ++ 2 files changed, 92 insertions(+), 11 deletions(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c index 3b7c817c02..dcf4f0c921 100644 --- a/drivers/mtd/spi/spi-nor-core.c +++ b/drivers/mtd/spi/spi-nor-core.c @@ -3526,6 +3526,18 @@ static struct spi_nor_fixups mt35xu512aba_fixups = { }; #endif /* CONFIG_SPI_FLASH_MT35XU */

+#ifdef CONFIG_SPI_FLASH_XTX +static void xtx25f32b_post_sfdp_fixup(struct spi_nor *nor, + struct spi_nor_flash_parameter *params) +{ + nor->flags |= SNOR_F_SOFT_RESET; +} + +static struct spi_nor_fixups xtx25f32b_fixups = { + .post_sfdp = xtx25f32b_post_sfdp_fixup, +}; +#endif + /** spi_nor_octal_dtr_enable() - enable Octal DTR I/O if needed * @nor: pointer to a 'struct spi_nor' * @@ -3603,6 +3615,53 @@ static int spi_nor_init(struct spi_nor *nor) }

#ifdef CONFIG_SPI_FLASH_SOFT_RESET +/** + * spi_nor_soft_reset_setup_op() - Initial setup of op for soft + * reset. Initializes nor->reset_proto iff needed. + * + * @nor: the spi_nor structure nor->reset_proto will be used or if + * null, it'll be assigned the used protocol, from a few + * protocols that get tried for device and controller + * support. + * + * @opcode operation code for soft reset (or soft reset enable, + * we currently assume they work the same in all systems) + * + * @op: pointer to operation struct to set up for reset or reset + * enable. + */ +static void spi_nor_soft_reset_setup_op(struct spi_nor *nor, u16 opcode, struct spi_mem_op *op) +{ + enum spi_nor_protocol reset_proto; + /** + * admitedly arbitrary list, to be improved if there's + * new knowledge of what works in different systems + */ + enum spi_nor_protocol reset_proto_candidates[] = { + SNOR_PROTO_8_8_8_DTR, SNOR_PROTO_1_1_1_DTR, SNOR_PROTO_8_8_8, + SNOR_PROTO_4_4_4, SNOR_PROTO_2_2_2, SNOR_PROTO_1_1_1 + }; + + if (nor->reset_proto) { + *op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 0), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DATA); + spi_nor_setup_op(nor, op, nor->reset_proto); + } else { + for (int i = 0; i < ARRAY_SIZE(reset_proto_candidates) && !nor->reset_proto ; i++) { + reset_proto = reset_proto_candidates[i]; + *op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 0), + SPI_MEM_OP_NO_DUMMY, + SPI_MEM_OP_NO_ADDR, + SPI_MEM_OP_NO_DATA); + spi_nor_setup_op(nor, op, reset_proto); + if (spi_mem_supports_op(nor->spi, op)) + nor->reset_proto = reset_proto; + } + } +} + /** * spi_nor_soft_reset() - perform the JEDEC Software Reset sequence * @nor: the spi_nor structure @@ -3621,11 +3680,7 @@ static int spi_nor_soft_reset(struct spi_nor *nor) ext = nor->cmd_ext_type; nor->cmd_ext_type = SPI_NOR_EXT_REPEAT;

- op = (struct spi_mem_op)SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_SRSTEN, 0), - SPI_MEM_OP_NO_DUMMY, - SPI_MEM_OP_NO_ADDR, - SPI_MEM_OP_NO_DATA); - spi_nor_setup_op(nor, &op, SNOR_PROTO_8_8_8_DTR); + spi_nor_soft_reset_setup_op(nor, SPINOR_OP_SRSTEN, &op); ret = spi_mem_exec_op(nor->spi, &op); if (ret) { dev_warn(nor->dev, "Software reset enable failed: %d\n", ret); @@ -3636,7 +3691,7 @@ static int spi_nor_soft_reset(struct spi_nor *nor) SPI_MEM_OP_NO_DUMMY, SPI_MEM_OP_NO_ADDR, SPI_MEM_OP_NO_DATA); - spi_nor_setup_op(nor, &op, SNOR_PROTO_8_8_8_DTR); + spi_nor_setup_op(nor, &op, nor->reset_proto); ret = spi_mem_exec_op(nor->spi, &op); if (ret) { dev_warn(nor->dev, "Software reset failed: %d\n", ret); @@ -3654,18 +3709,34 @@ out: nor->cmd_ext_type = ext; return ret; } -#endif /* CONFIG_SPI_FLASH_SOFT_RESET */ + +static bool flash_supports_proto(const struct flash_info *flash, enum spi_nor_protocol proto) +{ + switch (spi_nor_get_protocol_data_nbits(proto)) { + case 8: + return flash->flags & (spi_nor_protocol_is_dtr(proto) + ? SPI_NOR_OCTAL_DTR_READ + : SPI_NOR_OCTAL_READ); + case 4: return flash->flags & SPI_NOR_QUAD_READ; + case 2: return flash->flags & SPI_NOR_DUAL_READ; + default: + return 1; + } +}

int spi_nor_remove(struct spi_nor *nor) { -#ifdef CONFIG_SPI_FLASH_SOFT_RESET - if (nor->info->flags & SPI_NOR_OCTAL_DTR_READ && + if (flash_supports_proto(nor->info, nor->reset_proto) && nor->flags & SNOR_F_SOFT_RESET) return spi_nor_soft_reset(nor); -#endif - return 0; } +#else /* !CONFIG_SPI_FLASH_SOFT_RESET */ +int spi_nor_remove(struct spi_nor *nor) +{ + return 0; +} +#endif /* CONFIG_SPI_FLASH_SOFT_RESET */

void spi_nor_set_fixups(struct spi_nor *nor) { @@ -3696,6 +3767,11 @@ void spi_nor_set_fixups(struct spi_nor *nor) if (!strcmp(nor->info->name, "mt35xu512aba")) nor->fixups = &mt35xu512aba_fixups; #endif + +#ifdef CONFIG_SPI_FLASH_XTX + if (!strcmp(nor->info->name, "xt25f32b")) + nor->fixups = &xtx25f32b_fixups; +#endif }

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 4ceeae623d..550527ab0c 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -490,6 +490,8 @@ struct spi_flash { * @read_proto: the SPI protocol for read operations * @write_proto: the SPI protocol for write operations * @reg_proto the SPI protocol for read_reg/write_reg/erase operations + * @reset_proto: The SPI protocol for soft reset to return to state expected + * by OS before running the OS (at remove time) or at sf probe * @cmd_buf: used by the write_reg * @cmd_ext_type: the command opcode extension for DTR mode. * @fixups: flash-specific fixup hooks. @@ -535,6 +537,9 @@ struct spi_nor { enum spi_nor_protocol read_proto; enum spi_nor_protocol write_proto; enum spi_nor_protocol reg_proto; +#ifdef CONFIG_SPI_FLASH_SOFT_RESET + enum spi_nor_protocol reset_proto; +#endif bool sst_write_second; u32 flags; u8 cmd_buf[SPI_NOR_MAX_CMD_SIZE];