sysfs-bus-i2c-devices-m24lr

  1What:           /sys/bus/i2c/devices/<busnum>-<primary-addr>/unlock
  2Date:           2025-07-04
  3KernelVersion:  6.17
  4Contact:        Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
  5Description:
  6                Write-only attribute used to present a password and unlock
  7                access to protected areas of the M24LR chip, including
  8                configuration registers such as the Sector Security Status
  9                (SSS) bytes. A valid password must be written to enable write
 10                access to these regions via the I2C interface.
 11
 12                Format:
 13                  - Hexadecimal string representing a 32-bit (4-byte) password
 14                  - Accepts 1 to 8 hex digits (e.g., "c", "1F", "a1b2c3d4")
 15                  - No "0x" prefix, whitespace, or trailing newline
 16                  - Case-insensitive
 17
 18                Behavior:
 19                  - If the password matches the internal stored value,
 20                    access to protected memory/configuration is granted
 21                  - If the password does not match the internally stored value,
 22                    it will fail silently
 23
 24What:           /sys/bus/i2c/devices/<busnum>-<primary-addr>/new_pass
 25Date:           2025-07-04
 26KernelVersion:  6.17
 27Contact:        Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
 28Description:
 29                Write-only attribute used to update the password required to
 30                unlock the M24LR chip.
 31
 32                Format:
 33                  - Hexadecimal string representing a new 32-bit password
 34                  - Accepts 1 to 8 hex digits (e.g., "1A", "ffff", "c0ffee00")
 35                  - No "0x" prefix, whitespace, or trailing newline
 36                  - Case-insensitive
 37
 38                Behavior:
 39                  - Overwrites the current password stored in the I2C password
 40                    register
 41                  - Requires the device to be unlocked before changing the
 42                    password
 43                  - If the device is locked, the write silently fails
 44
 45What:           /sys/bus/i2c/devices/<busnum>-<primary-addr>/uid
 46Date:           2025-07-04
 47KernelVersion:  6.17
 48Contact:        Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
 49Description:
 50                Read-only attribute that exposes the 8-byte unique identifier
 51                programmed into the M24LR chip at the factory.
 52
 53                Format:
 54                  - Lowercase hexadecimal string representing a 64-bit value
 55                  - 1 to 16 hex digits (e.g., "e00204f12345678")
 56                  - No "0x" prefix
 57                  - Includes a trailing newline
 58
 59What:           /sys/bus/i2c/devices/<busnum>-<primary-addr>/total_sectors
 60Date:           2025-07-04
 61KernelVersion:  6.17
 62Contact:        Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
 63Description:
 64                Read-only attribute that exposes the total number of EEPROM
 65                sectors available in the M24LR chip.
 66
 67                Format:
 68                  - 1 to 2 hex digits (e.g. "F")
 69                  - No "0x" prefix
 70                  - Includes a trailing newline
 71
 72                Notes:
 73                  - Value is encoded by the chip and corresponds to the EEPROM
 74                    size (e.g., 3 = 4 kbit for M24LR04E-R)
 75
 76What:           /sys/bus/i2c/devices/<busnum>-<primary-addr>/sss
 77Date:           2025-07-04
 78KernelVersion:  6.17
 79Contact:        Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
 80Description:
 81                Read/write binary attribute representing the Sector Security
 82                Status (SSS) bytes for all EEPROM sectors in STMicroelectronics
 83                M24LR chips.
 84
 85                Each EEPROM sector has one SSS byte, which controls I2C and
 86                RF access through protection bits and optional password
 87                authentication.
 88
 89                Format:
 90                  - The file contains one byte per EEPROM sector
 91                  - Byte at offset N corresponds to sector N
 92                  - Binary access only; use tools like dd, Python, or C that
 93                    support byte-level I/O and offset control.
 94
 95                Notes:
 96                  - The number of valid bytes in this file is equal to the
 97                    value exposed by 'total_sectors' file
 98                  - Write access requires prior password authentication in
 99                    I2C mode
100                  - Refer to the M24LR datasheet for full SSS bit layout