Nor device (is25wp256 mounted on HiFive unleashed Rev A00 board) from ISSI have memory blocks guarded by block protection bits BP[0,1,2,3]. Add an identifier within the flash info structure to indicate that a particular flash device has the fourth block protect bit (SPI_NOR_HAS_BP3).
Increase size of flash_info flags from u16 to u32 to avoid flag overflow due SPI_NOR_HAS_BP3. Clear block protection bits unlocks the flash memory regions. Based on code developed by Wesley Terpstra <wes...@sifive.com> and/or Palmer Dabbelt <pal...@sifive.com>. https://github.com/riscv/riscv-linux/commit/c94e267766d62bc9a669611c3d0c8ed5ea26569b spell correction: "Configuration" in spansion_quad_enable function description. Signed-off-by: Sagar Shrikant Kadam <sagar.ka...@sifive.com> --- drivers/mtd/spi-nor/spi-nor.c | 72 ++++++++++++++++++++++++++++++++++++++++--- include/linux/mtd/spi-nor.h | 2 ++ 2 files changed, 70 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index 315eeec..4ed241d 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -250,7 +250,7 @@ struct flash_info { u16 page_size; u16 addr_width; - u16 flags; + u32 flags; #define SECT_4K BIT(0) /* SPINOR_OP_BE_4K works uniformly */ #define SPI_NOR_NO_ERASE BIT(1) /* No erase command needed */ #define SST_WRITE BIT(2) /* use SST byte programming */ @@ -279,6 +279,13 @@ struct flash_info { #define SPI_NOR_SKIP_SFDP BIT(13) /* Skip parsing of SFDP tables */ #define USE_CLSR BIT(14) /* use CLSR command */ #define SPI_NOR_OCTAL_READ BIT(15) /* Flash supports Octal Read */ +#define SPI_NOR_HAS_BP3 BIT(16) /* + * Flash SR has block protect bits + * for lock/unlock purpose, few support + * BP0-BP2 while few support BP0-BP3. + * This flag identifies devices that + * support BP3 bit. + */ /* Part specific fixup hooks. */ const struct spi_nor_fixups *fixups; @@ -1461,7 +1468,55 @@ static int macronix_quad_enable(struct spi_nor *nor) } /** - * spansion_quad_enable() - set QE bit in Configuraiton Register. + * issi_unlock() - clear BP[0123] write-protection. + * @nor: pointer to a 'struct spi_nor'. + * @ofs: offset from which to unlock memory. + * @len: number of bytes to unlock. + * + * Bits [2345] of the Status Register are BP[0123]. + * ISSI chips use a different block protection scheme than other chips. + * Just disable the write-protect unilaterally. + * + * Return: 0 on success, -errno otherwise. + */ +static int issi_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len) +{ + int ret, val; + u8 mask; + + if (nor->flags & SNOR_F_HAS_BP3) + mask = SR_BP3 | SR_BP2 | SR_BP1 | SR_BP0; + else + mask = SR_BP2 | SR_BP1 | SR_BP0; + + val = read_sr(nor); + if (val < 0) + return val; + if (!(val & mask)) + return 0; + + write_enable(nor); + + write_sr(nor, val & ~mask); + + ret = spi_nor_wait_till_ready(nor); + if (ret) + return ret; + + ret = read_sr(nor); + if (ret > 0 && !(ret & mask)) { + dev_info(nor->dev, "ISSI block protect bits cleared SR: 0x%x\n", + ret); + ret = 0; + } else { + dev_err(nor->dev, "ISSI block protect bits not cleared\n"); + ret = -EINVAL; + } + return ret; +} + +/** + * spansion_quad_enable() - set QE bit in Configuration Register. * @nor: pointer to a 'struct spi_nor' * * Set the Quad Enable (QE) bit in the Configuration Register. @@ -1859,8 +1914,10 @@ static int sr2_bit7_quad_enable(struct spi_nor *nor) SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) }, { "is25wp256", INFO(0x9d7019, 0, 64 * 1024, 1024, SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ | - SPI_NOR_4B_OPCODES) - .fixups = &is25lp256_fixups }, + SPI_NOR_4B_OPCODES | SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB | + SPI_NOR_HAS_BP3) + .fixups = &is25lp256_fixups + }, /* Macronix */ { "mx25l512e", INFO(0xc22010, 0, 64 * 1024, 1, SECT_4K) }, { "mx25l2005a", INFO(0xc22012, 0, 64 * 1024, 4, SECT_4K) }, @@ -4110,6 +4167,13 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, nor->flash_is_locked = stm_is_locked; } + /* NOR protection support for ISSI chips */ + if (JEDEC_MFR(info) == SNOR_MFR_ISSI && + info->flags & SPI_NOR_HAS_LOCK && + info->flags & SPI_NOR_HAS_BP3) { + nor->flash_unlock = issi_unlock; + } + if (nor->flash_lock && nor->flash_unlock && nor->flash_is_locked) { mtd->_lock = spi_nor_lock; mtd->_unlock = spi_nor_unlock; diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index b0e42b3..f6fa70f 100644 --- a/include/linux/mtd/spi-nor.h +++ b/include/linux/mtd/spi-nor.h @@ -127,6 +127,7 @@ #define SR_BP0 BIT(2) /* Block protect 0 */ #define SR_BP1 BIT(3) /* Block protect 1 */ #define SR_BP2 BIT(4) /* Block protect 2 */ +#define SR_BP3 BIT(5) /* Block protect 3 */ #define SR_TB BIT(5) /* Top/Bottom protect */ #define SR_SRWD BIT(7) /* SR write protect */ /* Spansion/Cypress specific status bits */ @@ -244,6 +245,7 @@ enum spi_nor_option_flags { SNOR_F_BROKEN_RESET = BIT(6), SNOR_F_4B_OPCODES = BIT(7), SNOR_F_HAS_4BAIT = BIT(8), + SNOR_F_HAS_BP3 = BIT(9), }; /** -- 1.9.1
