The 1-Wire bus in Linux

These devices have a strange support in Linux, that is, they are fully managed by the sysfs interface and no special files are present in the /dev directory as usual.

Note

In reality, there is another communication method between the 1-Wire core and the user space, which is not covered in this book. You can get further information by reading the Documentation/w1/w1.netlink file in the kernel's repository.

For each master, there exists a dedicated directory (as seen earlier) where several files are located, and this directory can be used to set up our controller. Here is an example from the controller emulated earlier:

root@bbb:~# ls /sys/bus/w1/devices/w1_bus_master1/
00-800000000000  w1_master_attempts        w1_master_search
driver           w1_master_max_slave_count w1_master_slave_count
power            w1_master_name            w1_master_slaves
subsystem        w1_master_pointer         w1_master_timeout
uevent           w1_master_pullup          w1_master_timeout_us...