/sys/class/i2c-adapter/i2c-0/new_device will Instantiate a new device from user-space. File new_device takes 2 parameters: the name of the I2C device (a string) and the address of the I2C device (a number, typically expressed in hexadecimal starting with 0x, but can also be expressed in decimal.) Read more
pcf8563 likely refers to "Real-time clock/calendar".
Hope that helps. I found it by downloading the kernel source code and then finding keywords using "grep -irl".