Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-bus-i2c-devices-m24lr
Extension
[no extension]
Size
4440 bytes
Lines
101
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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

Annotation

Implementation Notes