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     owc — Dallas Semiconductor 1-Wire Controller


     device owc


     The owc module implements Dallas Semiconductor 1-Wire signaling.  It attaches the ow(4)
     driver 1-Wire bus protocol.  The owc device implements the Link Layer of the 1-Wire bus
     protocol stack.

     Bit banging a pin on a gpiobus(4) is the only supported controller.  Both standard and
     overdrive transfer timings are implemented.  Strong pull-up functionality needed to support
     parasitic mode is not implemented.

     To enable 1-Wire for FDT systems requires modifying the DTS for your board to add something

     / {
             onewire {
                     compatible = "w1-gpio";
                     gpios = <&gpio 4 1>;

     The gpios property describes the GPIO pin the 1-Wire bus is connected to.  For more details
     about the gpios property, please consult /usr/src/sys/dts/bindings-gpio.txt.

     On a device.hints(5) based system these values are required for the owc:     The gpiobus you are attaching to.

     hint.owc.%d.pins   This is a bitmask that defines a pin on the gpiobus that is to be used
                        for the 1-Wire bus.  For instance, to configure pin 10, use the bitmask
                        of 0x400.  Please note that this mask should have only one bit set (any
                        other bits - i.e., pins - will be ignored).


     gpiobus(4), ow(4), ow_temp(4), owll(9), own(9)


     1-Wire is a registered trademark of Maxim Integrated Products, Inc.


     The owc driver first appeared in FreeBSD 11.0.


     The owc device driver and this manual page were written by Warner Losh.


     The gpio driver implements timing by busy waiting, which can cause a high load on slower


     Overdrive mode has not actually been tested.