This patch adds supports for SFDP (JESD216B) 4-byte Address Instruction Table. This table is optional but when available, we parse it to get the 4-byte address op codes supported by the memory. Using these op codes is stateless as opposed to entering the 4-byte address mode or setting the Base Address Register (BAR).
Signed-off-by: Cyrille Pitchen <[email protected]> --- drivers/mtd/spi-nor/spi-nor.c | 166 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 165 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index ce8722055a9c..ea044efc4e6d 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1899,6 +1899,7 @@ struct sfdp_parameter_header { #define SFDP_BFPT_ID 0xff00u /* Basic Flash Parameter Table */ +#define SFDP_4BAIT_ID 0xff84u /* 4-byte Address Instruction Table */ #define SFDP_SIGNATURE 0x50444653u #define SFDP_JESD216_MAJOR 1 @@ -2241,6 +2242,149 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor, return 0; } +struct sfdp_4bait { + /* The hardware capability. */ + u32 hwcaps; + + /* + * The <supported_bit> bit in DWORD1 of the 4BAIT tells us whether + * the associated 4-byte address op code is supported. + */ + u32 supported_bit; +}; + +static int spi_nor_parse_4bait(struct spi_nor *nor, + const struct sfdp_parameter_header *param_header, + struct spi_nor_flash_parameter *params) +{ + static const struct sfdp_4bait reads[] = { + { SNOR_HWCAPS_READ, BIT(0) }, + { SNOR_HWCAPS_READ_FAST, BIT(1) }, + { SNOR_HWCAPS_READ_1_1_2, BIT(2) }, + { SNOR_HWCAPS_READ_1_2_2, BIT(3) }, + { SNOR_HWCAPS_READ_1_1_4, BIT(4) }, + { SNOR_HWCAPS_READ_1_4_4, BIT(5) }, + { SNOR_HWCAPS_READ_1_1_1_DTR, BIT(13) }, + { SNOR_HWCAPS_READ_1_2_2_DTR, BIT(14) }, + { SNOR_HWCAPS_READ_1_4_4_DTR, BIT(15) }, + }; + static const struct sfdp_4bait programs[] = { + { SNOR_HWCAPS_PP, BIT(6) }, + { SNOR_HWCAPS_PP_1_1_4, BIT(7) }, + { SNOR_HWCAPS_PP_1_4_4, BIT(8) }, + }; + static const struct sfdp_4bait erases[SNOR_CMD_ERASE_MAX] = { + { 0u /* not used */, BIT(9) }, + { 0u /* not used */, BIT(10) }, + { 0u /* not used */, BIT(11) }, + { 0u /* not used */, BIT(12) }, + }; + u32 dwords[2], addr, discard_hwcaps, read_hwcaps, pp_hwcaps, erase_mask; + struct spi_nor_erase_map *map = &nor->erase_map; + int i, err; + + if (param_header->major != SFDP_JESD216_MAJOR || + param_header->length < ARRAY_SIZE(dwords)) + return -EINVAL; + + /* Read the 4-byte Address Instruction Table. */ + addr = SFDP_PARAM_HEADER_PTP(param_header); + err = spi_nor_read_sfdp(nor, addr, sizeof(dwords), dwords); + if (err) + return err; + + /* Fix endianness of the 4BAIT DWORDs. */ + for (i = 0; i < ARRAY_SIZE(dwords); i++) + dwords[i] = le32_to_cpu(dwords[i]); + + /* + * Compute the subset of (Fast) Read commands for which the 4-byte + * version is supported. + */ + discard_hwcaps = 0; + read_hwcaps = 0; + for (i = 0; i < ARRAY_SIZE(reads); i++) { + const struct sfdp_4bait *read = &reads[i]; + + discard_hwcaps |= read->hwcaps; + if ((params->hwcaps.mask & read->hwcaps) && + (dwords[0] & read->supported_bit)) + read_hwcaps |= read->hwcaps; + } + + /* + * Compute the subset of Page Program commands for which the 4-byte + * version is supported. + */ + pp_hwcaps = 0; + for (i = 0; i < ARRAY_SIZE(programs); i++) { + const struct sfdp_4bait *program = &programs[i]; + + discard_hwcaps |= program->hwcaps; + if ((params->hwcaps.mask & program->hwcaps) && + (dwords[0] & program->supported_bit)) + pp_hwcaps |= program->hwcaps; + } + + /* + * Compute the subet of Sector Erase commands for which the 4-byte + * version is supported. + */ + erase_mask = 0; + for (i = 0; i < SNOR_CMD_ERASE_MAX; i++) { + const struct sfdp_4bait *erase = &erases[i]; + + if ((map->commands[i].size > 0) && + (dwords[0] & erase->supported_bit)) + erase_mask |= BIT(i); + } + + /* + * We need at least one 4-byte op code per read, program and erase + * operation; the .read(), .write() and .erase() hooks share the + * nor->addr_width value. + */ + if (!read_hwcaps || !pp_hwcaps || !erase_mask) + return 0; + + /* + * Discard all operations from the 4-byte instruction set which are + * not supported by this memory. + */ + params->hwcaps.mask &= ~discard_hwcaps; + params->hwcaps.mask |= (read_hwcaps | pp_hwcaps); + + /* Use the 4-byte address instruction set. */ + for (i = 0; i < SNOR_CMD_READ_MAX; i++) { + struct spi_nor_read_command *read_cmd = ¶ms->reads[i]; + + read_cmd->opcode = spi_nor_convert_3to4_read(read_cmd->opcode); + } + for (i = 0; i < SNOR_CMD_PP_MAX; i++) { + struct spi_nor_pp_command *pp_cmd = ¶ms->page_programs[i]; + + pp_cmd->opcode = spi_nor_convert_3to4_program(pp_cmd->opcode); + } + for (i = 0; i < SNOR_CMD_ERASE_MAX; i++) { + struct spi_nor_erase_command *erase_cmd = &map->commands[i]; + + if (erase_mask & BIT(i)) + erase_cmd->opcode = (dwords[1] >> (i * 8)) & 0xFF; + else + spi_nor_set_erase_command(erase_cmd, 0u, 0xFF); + } + + /* + * We set nor->addr_width here to skip spi_nor_set_4byte_opcodes() + * later because this latest function implements a legacy quirk for + * the erase size of Spansion memory. However this quirk is no longer + * needed with new SFDP compliant memories. + */ + nor->addr_width = 4; + nor->flags |= SNOR_F_4B_OPCODES; + return 0; +} + static int spi_nor_parse_sfdp(struct spi_nor *nor, struct spi_nor_flash_parameter *params) { @@ -2308,6 +2452,23 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor, if (err) goto exit; + /* Parse other parameter headers. */ + for (i = 0; i < header.nph; i++) { + param_header = ¶m_headers[i]; + + switch (SFDP_PARAM_HEADER_ID(param_header)) { + case SFDP_4BAIT_ID: + err = spi_nor_parse_4bait(nor, param_header, params); + break; + + default: + break; + } + + if (err) + goto exit; + } + exit: kfree(param_headers); return err; @@ -2885,7 +3046,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, if (ret) return ret; - if (info->addr_width) + if (nor->addr_width) + /* already configured by spi_nor_setup() */ + ; + else if (info->addr_width) nor->addr_width = info->addr_width; else if (mtd->size > 0x1000000) { /* enable 4-byte addressing if the device exceeds 16MiB */ -- 2.9.3
