[PATCH v2 4/4] mtd: spi-nor: implement OTP support for Winbond and similar flashes
Heiko Thiery
heiko.thiery at gmail.com
Thu Oct 1 01:35:51 EDT 2020
HI Michael,
Am Sa., 12. Sept. 2020 um 00:26 Uhr schrieb Michael Walle <michael at walle.cc>:
>
> Use the new OTP ops to implement OTP access on Winbond flashes. Most
> Winbond flashes provides up to four different OTP areas ("Security
> Registers"). Newer flashes uses the first OTP area for SFDP data. Thus,
> for these flashes only the last three areas are handled and the first
> one is left untouched.
>
> This was tested on a Winbond W25Q32JW as well as on a W25Q32FW.
>
> Signed-off-by: Michael Walle <michael at walle.cc>
Reviewed-by: Heiko Thiery <heiko.thiery at gmail.com>
> ---
> drivers/mtd/spi-nor/core.c | 161 ++++++++++++++++++++++++++++++++++
> drivers/mtd/spi-nor/core.h | 4 +
> drivers/mtd/spi-nor/winbond.c | 18 +++-
> include/linux/mtd/spi-nor.h | 10 +++
> 4 files changed, 191 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 348db19958e9..c150e3b6ee44 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2997,6 +2997,167 @@ int spi_nor_otp_is_locked_scur(struct spi_nor *nor, unsigned int region)
> return *scur & SCUR_LDSO;
> }
>
> +/**
> + * spi_nor_otp_read_secr() - read OTP data
> + * @nor: pointer to 'struct spi_nor'
> + * @from: offset to read from
> + * @len: number of bytes to read
> + * @buf: pointer to dst buffer
> + *
> + * Read OTP data by using the SPINOR_OP_RSECR commands. This method is used on
> + * GigaDevice and Winbond flashes.
> + *
> + * Return: number of bytes read successfully, -errno otherwise
> + */
> +int spi_nor_otp_read_secr(struct spi_nor *nor, loff_t addr, uint64_t len, u8 *buf)
> +{
> + u8 addr_width, read_opcode, read_dummy;
> + struct spi_mem_dirmap_desc *rdesc;
> + enum spi_nor_protocol read_proto;
> + int ret;
> +
> + read_opcode = nor->read_opcode;
> + addr_width = nor->addr_width;
> + read_dummy = nor->read_dummy;
> + read_proto = nor->read_proto;
> + rdesc = nor->dirmap.rdesc;
> +
> + nor->read_opcode = SPINOR_OP_RSECR;
> + nor->addr_width = 3;
> + nor->read_dummy = 8;
> + nor->read_proto = SNOR_PROTO_1_1_1;
> + nor->dirmap.rdesc = NULL;
> +
> + ret = spi_nor_read_data(nor, addr, len, buf);
> +
> + nor->read_opcode = read_opcode;
> + nor->addr_width = addr_width;
> + nor->read_dummy = read_dummy;
> + nor->read_proto = read_proto;
> + nor->dirmap.rdesc = rdesc;
> +
> + return ret;
> +}
> +
> +/**
> + * spi_nor_otp_write_secr() - write OTP data
> + * @nor: pointer to 'struct spi_nor'
> + * @to: offset to write to
> + * @len: number of bytes to write
> + * @buf: pointer to src buffer
> + *
> + * Write OTP data by using the SPINOR_OP_PSECR commands. This method is used on
> + * GigaDevice and Winbond flashes.
> + *
> + * Return: number of bytes written successfully, -errno otherwise
> + */
> +int spi_nor_otp_write_secr(struct spi_nor *nor, loff_t addr, uint64_t len, u8 *buf)
> +{
> + enum spi_nor_protocol write_proto;
> + struct spi_mem_dirmap_desc *wdesc;
> + u8 addr_width, program_opcode;
> + int ret;
> +
> + program_opcode = nor->program_opcode;
> + addr_width = nor->addr_width;
> + write_proto = nor->write_proto;
> + wdesc = nor->dirmap.wdesc;
> +
> + nor->program_opcode = SPINOR_OP_PSECR;
> + nor->addr_width = 3;
> + nor->write_proto = SNOR_PROTO_1_1_1;
> + nor->dirmap.wdesc = NULL;
> +
> + /*
> + * We only support a write to one single page. For now all winbond
> + * flashes only have one page per OTP region.
> + */
> + ret = spi_nor_write_enable(nor);
> + if (ret)
> + goto out;
> +
> + ret = spi_nor_write_data(nor, addr, len, buf);
> + if (ret < 0)
> + goto out;
> +
> + ret = spi_nor_wait_till_ready(nor);
> +
> +out:
> + nor->program_opcode = program_opcode;
> + nor->addr_width = addr_width;
> + nor->write_proto = write_proto;
> + nor->dirmap.wdesc = wdesc;
> +
> + return ret;
> +}
> +
> +static int spi_nor_otp_lock_bit_cr(unsigned int region)
> +{
> + static const int lock_bits[] = { SR2_LB1, SR2_LB2, SR2_LB3 };
> +
> + if (region >= ARRAY_SIZE(lock_bits))
> + return -EINVAL;
> +
> + return lock_bits[region];
> +}
> +
> +/**
> + * spi_nor_otp_lock_sr2() - lock the OTP region
> + * @nor: pointer to 'struct spi_nor'
> + * @region: OTP region
> + *
> + * Lock the OTP region by writing the status register-2. This method is used on
> + * GigaDevice and Winbond flashes.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
> +int spi_nor_otp_lock_sr2(struct spi_nor *nor, unsigned int region)
> +{
> + int lock_bit;
> + u8 *sr2 = nor->bouncebuf;
> + int ret;
> +
> + lock_bit = spi_nor_otp_lock_bit_cr(region);
> + if (lock_bit < 0)
> + return lock_bit;
> +
> + ret = spi_nor_read_cr(nor, sr2);
> + if (ret)
> + return ret;
> +
> + /* check if its already locked */
> + if (*sr2 & lock_bit)
> + return 0;
> +
> + return spi_nor_write_16bit_cr_and_check(nor, *sr2 | lock_bit);
> +}
> +
> +/**
> + * spi_nor_otp_is_locked_sr2() - get the OTP region lock status
> + * @nor: pointer to 'struct spi_nor'
> + * @region: OTP region
> + *
> + * Retrieve the OTP region lock bit by reading the status register-2. This
> + * method is used on GigaDevice and Winbond flashes.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
> +int spi_nor_otp_is_locked_sr2(struct spi_nor *nor, unsigned int region)
> +{
> + int lock_bit;
> + u8 *sr2 = nor->bouncebuf;
> + int ret;
> +
> + lock_bit = spi_nor_otp_lock_bit_cr(region);
> + if (lock_bit < 0)
> + return lock_bit;
> +
> + ret = spi_nor_read_cr(nor, sr2);
> + if (ret)
> + return ret;
> +
> + return (*sr2 & lock_bit);
> +}
>
> static int spi_nor_init(struct spi_nor *nor)
> {
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index 7ec4add17b72..74bbb7aef1f1 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -472,6 +472,10 @@ int spi_nor_otp_read_otp_mode(struct spi_nor *nor, loff_t from, uint64_t len, u8
> int spi_nor_otp_write_otp_mode(struct spi_nor *nor, loff_t to, uint64_t len, u8 *buf);
> int spi_nor_otp_lock_scur(struct spi_nor *nor, unsigned int region);
> int spi_nor_otp_is_locked_scur(struct spi_nor *nor, unsigned int region);
> +int spi_nor_otp_read_secr(struct spi_nor *nor, loff_t addr, uint64_t len, u8 *buf);
> +int spi_nor_otp_write_secr(struct spi_nor *nor, loff_t addr, uint64_t len, u8 *buf);
> +int spi_nor_otp_lock_sr2(struct spi_nor *nor, unsigned int region);
> +int spi_nor_otp_is_locked_sr2(struct spi_nor *nor, unsigned int region);
>
> int spi_nor_hwcaps_read2cmd(u32 hwcaps);
> u8 spi_nor_convert_3to4_read(u8 opcode);
> diff --git a/drivers/mtd/spi-nor/winbond.c b/drivers/mtd/spi-nor/winbond.c
> index 6dcde15fb1aa..3b14e96e993f 100644
> --- a/drivers/mtd/spi-nor/winbond.c
> +++ b/drivers/mtd/spi-nor/winbond.c
> @@ -55,14 +55,19 @@ static const struct flash_info winbond_parts[] = {
> { "w25q32", INFO(0xef4016, 0, 64 * 1024, 64, SECT_4K) },
> { "w25q32dw", INFO(0xef6016, 0, 64 * 1024, 64,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> - SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB) },
> + SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
> + OTP_INFO(256, 3, 0x1000, 0x1000)
> + },
> +
> { "w25q32jv", INFO(0xef7016, 0, 64 * 1024, 64,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
> },
> { "w25q32jwm", INFO(0xef8016, 0, 64 * 1024, 64,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
> - SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB) },
> + SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
> + OTP_INFO(256, 3, 0x1000, 0x1000)
> + },
> { "w25x64", INFO(0xef3017, 0, 64 * 1024, 128, SECT_4K) },
> { "w25q64", INFO(0xef4017, 0, 64 * 1024, 128,
> SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> @@ -122,9 +127,18 @@ static int winbond_set_4byte_addr_mode(struct spi_nor *nor, bool enable)
> return spi_nor_write_disable(nor);
> }
>
> +static const struct spi_nor_otp_ops winbond_otp_ops = {
> + .read = spi_nor_otp_read_secr,
> + .write = spi_nor_otp_write_secr,
> + .lock = spi_nor_otp_lock_sr2,
> + .is_locked = spi_nor_otp_is_locked_sr2,
> +};
> +
> static void winbond_default_init(struct spi_nor *nor)
> {
> nor->params->set_4byte_addr_mode = winbond_set_4byte_addr_mode;
> + if (nor->params->otp_info.n_otps)
> + nor->params->otp_ops = &winbond_otp_ops;
> }
>
> static const struct spi_nor_fixups winbond_fixups = {
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index 04195d3e43b8..4750fb631c96 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -110,6 +110,11 @@
> #define SPINOR_OP_RD_EVCR 0x65 /* Read EVCR register */
> #define SPINOR_OP_WD_EVCR 0x61 /* Write EVCR register */
>
> +/* Used for GigaDevices and Winbond flashes. */
> +#define SPINOR_OP_ESECR 0x44 /* Erase Security registers */
> +#define SPINOR_OP_PSECR 0x42 /* Program Security registers */
> +#define SPINOR_OP_RSECR 0x48 /* Read Security registers */
> +
> /* Status Register bits. */
> #define SR_WIP BIT(0) /* Write in progress */
> #define SR_WEL BIT(1) /* Write enable latch */
> @@ -141,8 +146,13 @@
>
> /* Status Register 2 bits. */
> #define SR2_QUAD_EN_BIT1 BIT(1)
> +#define SR2_LB0 BIT(2) /* Security Register Lock Bit 0 */
> +#define SR2_LB1 BIT(3) /* Security Register Lock Bit 1 */
> +#define SR2_LB2 BIT(4) /* Security Register Lock Bit 2 */
> +#define SR2_LB3 BIT(5) /* Security Register Lock Bit 3 */
> #define SR2_QUAD_EN_BIT7 BIT(7)
>
> +
> /* Supported SPI protocols */
> #define SNOR_PROTO_INST_MASK GENMASK(23, 16)
> #define SNOR_PROTO_INST_SHIFT 16
>
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