diff options
Diffstat (limited to 'drivers/mtd/spi-nor/otp.c')
| -rw-r--r-- | drivers/mtd/spi-nor/otp.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/mtd/spi-nor/otp.c b/drivers/mtd/spi-nor/otp.c index 075b7290a95d..5021d40dffbf 100644 --- a/drivers/mtd/spi-nor/otp.c +++ b/drivers/mtd/spi-nor/otp.c @@ -14,6 +14,170 @@ #define spi_nor_otp_region_len(nor) ((nor)->params->otp.org->len) #define spi_nor_otp_n_regions(nor) ((nor)->params->otp.org->n_regions) +/** + * 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 from one region 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, size_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 to one region by using the SPINOR_OP_PSECR commands. This + * method is used on GigaDevice and Winbond flashes. + * + * Please note, the write must not span multiple OTP regions. + * + * Return: number of bytes written successfully, -errno otherwise + */ +int spi_nor_otp_write_secr(struct spi_nor *nor, loff_t addr, size_t len, u8 *buf) +{ + enum spi_nor_protocol write_proto; + struct spi_mem_dirmap_desc *wdesc; + u8 addr_width, program_opcode; + int ret, written; + + 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; + + written = spi_nor_write_data(nor, addr, len, buf); + if (written < 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 ?: written; +} + +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) +{ + u8 *cr = nor->bouncebuf; + int ret, lock_bit; + + lock_bit = spi_nor_otp_lock_bit_cr(region); + if (lock_bit < 0) + return lock_bit; + + ret = spi_nor_read_cr(nor, cr); + if (ret) + return ret; + + /* no need to write the register if region is already locked */ + if (cr[0] & lock_bit) + return 0; + + cr[0] |= lock_bit; + + return spi_nor_write_16bit_cr_and_check(nor, cr[0]); +} + +/** + * 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) +{ + u8 *cr = nor->bouncebuf; + int ret, lock_bit; + + lock_bit = spi_nor_otp_lock_bit_cr(region); + if (lock_bit < 0) + return lock_bit; + + ret = spi_nor_read_cr(nor, cr); + if (ret) + return ret; + + return cr[0] & lock_bit; +} + static loff_t spi_nor_otp_region_start(const struct spi_nor *nor, unsigned int region) { const struct spi_nor_otp_organization *org = nor->params->otp.org; |