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Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr | 100 |
1 files changed, 100 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr b/Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr new file mode 100644 index 000000000000..7c51ce8d38ba --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr @@ -0,0 +1,100 @@ +What: /sys/bus/i2c/devices/<busnum>-<primary-addr>/unlock +Date: 2025-07-04 +KernelVersion: 6.17 +Contact: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> +Description: + Write-only attribute used to present a password and unlock + access to protected areas of the M24LR chip, including + configuration registers such as the Sector Security Status + (SSS) bytes. A valid password must be written to enable write + access to these regions via the I2C interface. + + Format: + - Hexadecimal string representing a 32-bit (4-byte) password + - Accepts 1 to 8 hex digits (e.g., "c", "1F", "a1b2c3d4") + - No "0x" prefix, whitespace, or trailing newline + - Case-insensitive + + Behavior: + - If the password matches the internal stored value, + access to protected memory/configuration is granted + - If the password does not match the internally stored value, + it will fail silently + +What: /sys/bus/i2c/devices/<busnum>-<primary-addr>/new_pass +Date: 2025-07-04 +KernelVersion: 6.17 +Contact: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> +Description: + Write-only attribute used to update the password required to + unlock the M24LR chip. + + Format: + - Hexadecimal string representing a new 32-bit password + - Accepts 1 to 8 hex digits (e.g., "1A", "ffff", "c0ffee00") + - No "0x" prefix, whitespace, or trailing newline + - Case-insensitive + + Behavior: + - Overwrites the current password stored in the I2C password + register + - Requires the device to be unlocked before changing the + password + - If the device is locked, the write silently fails + +What: /sys/bus/i2c/devices/<busnum>-<primary-addr>/uid +Date: 2025-07-04 +KernelVersion: 6.17 +Contact: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> +Description: + Read-only attribute that exposes the 8-byte unique identifier + programmed into the M24LR chip at the factory. + + Format: + - Lowercase hexadecimal string representing a 64-bit value + - 1 to 16 hex digits (e.g., "e00204f12345678") + - No "0x" prefix + - Includes a trailing newline + +What: /sys/bus/i2c/devices/<busnum>-<primary-addr>/total_sectors +Date: 2025-07-04 +KernelVersion: 6.17 +Contact: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> +Description: + Read-only attribute that exposes the total number of EEPROM + sectors available in the M24LR chip. + + Format: + - 1 to 2 hex digits (e.g. "F") + - No "0x" prefix + - Includes a trailing newline + + Notes: + - Value is encoded by the chip and corresponds to the EEPROM + size (e.g., 3 = 4 kbit for M24LR04E-R) + +What: /sys/bus/i2c/devices/<busnum>-<primary-addr>/sss +Date: 2025-07-04 +KernelVersion: 6.17 +Contact: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com> +Description: + Read/write binary attribute representing the Sector Security + Status (SSS) bytes for all EEPROM sectors in STMicroelectronics + M24LR chips. + + Each EEPROM sector has one SSS byte, which controls I2C and + RF access through protection bits and optional password + authentication. + + Format: + - The file contains one byte per EEPROM sector + - Byte at offset N corresponds to sector N + - Binary access only; use tools like dd, Python, or C that + support byte-level I/O and offset control. + + Notes: + - The number of valid bytes in this file is equal to the + value exposed by 'total_sectors' file + - Write access requires prior password authentication in + I2C mode + - Refer to the M24LR datasheet for full SSS bit layout |