diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-spi-eeprom | 11 | ||||
| -rw-r--r-- | drivers/misc/eeprom/at25.c | 38 |
2 files changed, 41 insertions, 8 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-spi-eeprom b/Documentation/ABI/testing/sysfs-class-spi-eeprom index 1ff757982079..f4bc7d9454cf 100644 --- a/Documentation/ABI/testing/sysfs-class-spi-eeprom +++ b/Documentation/ABI/testing/sysfs-class-spi-eeprom @@ -17,3 +17,14 @@ Description: from the device. This is a read-only attribute. + +What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/jedec_id +Date: January 2026 +KernelVersion: 6.19 +Contact: Patrick Wicki <patrick.wicki@siemens.com> +Description: + Contains the raw JEDEC ID bytes returned by the RDID (0x9f) command. The + bytes are exposed as a hex string in big-endian order as read from the + device. + + This is a read-only attribute. diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index 5b00921d07d2..bc2cfb75d9bb 100644 --- a/drivers/misc/eeprom/at25.c +++ b/drivers/misc/eeprom/at25.c @@ -34,6 +34,7 @@ */ #define FM25_SN_LEN 8 /* serial number length */ +#define FM25_MAX_ID_LEN 9 /* ID length */ #define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */ struct at25_data { @@ -44,6 +45,8 @@ struct at25_data { struct nvmem_config nvmem_config; struct nvmem_device *nvmem; u8 sernum[FM25_SN_LEN]; + u8 id[FM25_MAX_ID_LEN]; + u8 id_len; }; #define AT25_WREN 0x06 /* latch the write enable */ @@ -64,8 +67,6 @@ struct at25_data { #define AT25_INSTR_BIT3 0x08 /* additional address bit in instr */ -#define FM25_ID_LEN 9 /* ID length */ - /* * Specs often allow 5ms for a page write, sometimes 20ms; * it's important to recover from write timeouts. @@ -180,11 +181,25 @@ static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, ch } static DEVICE_ATTR_RO(sernum); -static struct attribute *sernum_attrs[] = { +static ssize_t jedec_id_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct at25_data *at25; + + at25 = dev_get_drvdata(dev); + + if (!at25->id_len) + return -EOPNOTSUPP; + + return sysfs_emit(buf, "%*phN\n", at25->id_len, at25->id); +} +static DEVICE_ATTR_RO(jedec_id); + +static struct attribute *at25_attrs[] = { &dev_attr_sernum.attr, + &dev_attr_jedec_id.attr, NULL, }; -ATTRIBUTE_GROUPS(sernum); +ATTRIBUTE_GROUPS(at25); /* * Poll Read Status Register with timeout @@ -378,7 +393,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) { struct at25_data *at25 = container_of(chip, struct at25_data, chip); u8 sernum[FM25_SN_LEN]; - u8 id[FM25_ID_LEN]; + u8 id[FM25_MAX_ID_LEN]; u32 val; int i; @@ -388,7 +403,12 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) chip->byte_len = val; } else { /* Get ID of chip */ - fm25_aux_read(at25, id, FM25_RDID, FM25_ID_LEN); + fm25_aux_read(at25, id, FM25_RDID, FM25_MAX_ID_LEN); + + /* Store the unprocessed ID for exposing via sysfs */ + memcpy(at25->id, id, FM25_MAX_ID_LEN); + at25->id_len = FM25_MAX_ID_LEN; + /* There are inside-out FRAM variations, detect them and reverse the ID bytes */ if (id[6] == 0x7f && id[2] == 0xc2) for (i = 0; i < ARRAY_SIZE(id) / 2; i++) { @@ -400,6 +420,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) } if (id[6] == 0xc2) { + at25->id_len = 9; switch (id[7]) { case 0x21 ... 0x26: chip->byte_len = BIT(id[7] - 0x21 + 4) * 1024; @@ -413,6 +434,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) return -ENODEV; } } else if (id[2] == 0x82 && id[3] == 0x06) { + at25->id_len = 8; switch (id[1]) { case 0x51 ... 0x54: /* CY15B102QSN ... CY15B204QSN */ @@ -424,7 +446,7 @@ static int at25_fram_to_chip(struct device *dev, struct spi_eeprom *chip) } } else { dev_err(dev, "Error: unrecognized JEDEC ID format: %*ph\n", - FM25_ID_LEN, id); + FM25_MAX_ID_LEN, id); return -ENODEV; } @@ -549,7 +571,7 @@ static struct spi_mem_driver at25_driver = { .driver = { .name = "at25", .of_match_table = at25_of_match, - .dev_groups = sernum_groups, + .dev_groups = at25_groups, }, .id_table = at25_spi_ids, }, |