OWC(4)

📦 version 15.1, in freebsd 14.5, freebsd 15.1, nixpkgs unstable

🌸 NAME 🌸

okay bestie, welcome to OWC(4) from the Kernel Interfaces Manual — this is the page for owc — Dallas Semiconductor 1-Wire Controller. 💖 it's giving niche kernel-interface main character energy, fr fr.

✨ SYNOPSIS ✨

the whole synopsis is literally:

device owc

🦋 DESCRIPTION 🦋

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.

🚨 warning bestie: strong pull-up functionality needed to support parasitic mode is not implemented — noted, no cap. 😭

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

/ {
        ...
        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:

  • hint.owc.%d.at — 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).

💜 SEE ALSO 💜

go read these too, iykyk:

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

🕰️ HISTORY 🕰️

The owc driver first appeared in FreeBSD 11.0.

👑 AUTHORS 👑

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

🫶 CAVEATS 🫶

The gpio driver implements timing by busy waiting, which can cause a high load on slower systems — lowkey noted.

💀 BUGS 💀

Overdrive mode has not actually been tested. not me pointing at the untested overdrive mode 🙈

okay bye bestie, this page is from Debian, dated June 26, 2019, and it's the OWC(4) manual — mwah 💋

📦 where this page comes from