i2cdump

Dump all registers of an I2C device

$ i2cdump [i2cbus] [device_address]

$ i2cdump -y [i2cbus] [device_address]

$ i2cdump [i2cbus] [device_address] [b|w|c|s|i]

$ i2cdump -r [start]-[end] [i2cbus] [device_address]

i2cdump [options] i2cbus deviceaddress [mode_]

i2cdump reads and displays all registers of an I2C device connected to a specified bus. It outputs a hexadecimal table showing register addresses and their contents, useful for debugging I2C hardware.
All addresses should be specified in hexadecimal notation. The i2cbus number can be determined using i2cdetect -l, and device addresses can be found with i2cdetect.

-y

Disable interactive confirmation (dangerous on some hardware)

Limit dump to registers in specified range

Byte mode (default for most devices)

Word mode (16-bit values)

Consecutive byte mode

SMBus block mode

I2C block mode

Accessing I2C devices can cause hardware issues on some systems. Always use the -y flag with caution. Reading from some registers may have side effects. Requires appropriate permissions (usually root or i2c group membership).

i2cdump is part of the i2c-tools package, providing userspace access to I2C buses. The I2C bus protocol was developed by Philips Semiconductor (now NXP) in 1982 for inter-chip communication.

i2cdetect(8), i2cget(8), i2cset(8)