On 03/23/2017 12:33 AM, Cyrille Pitchen wrote: > 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 <cyrille.pitc...@atmel.com> > --- > 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; > + }
Looks like there is a bit of repeated stuff here, maybe this can be pulled out ? > + /* > + * 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() */ > + ; I think you can drop this part. > + 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 */ > -- Best regards, Marek Vasut