mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-02 08:42:48 +00:00
c7b0edf219
It used to be required that a device be a child of gpiobus(4) to manipulate gpio pins. That requirement didn't work well for FDT-based systems with many cross-hierarchy users of gpio, so a more modern framework was created that removed the old hierarchy requirement. These changes adapt the owc_gpiobus driver to use the newer gpio_pin_* functions to acquire, release, and manipulate gpio pins. This allows a single driver to work for both hinted-attachment and fdt-based systems, and removes the requirement that any one-wire fdt nodes must appear at the root of the devicetree. Differential Revision: https://reviews.freebsd.org/D22710 |
||
|---|---|---|
| .. | ||
| ow_temp.c | ||
| ow.c | ||
| ow.h | ||
| owc_gpiobus.c | ||
| owll_if.m | ||
| owll.h | ||
| own_if.m | ||
| own.h | ||
| README.txt | ||
Quick Design Document for 1-wire bus In new bus terms, 1-wire devices are attached to 1-wire buses (ow) which are attached to a one wire bridge (owc). The implementation follows the terminology used in the Maxim AN927 Application note which defines the 1-wire bus as implemented for the iButton product. This is considered to be the canonical definition of the 1-wire bus. This means that the 1-wire bridge will implement the owll(9) interface. ow is one wire. ll is for Link Level to mirror the ISO stack terminology used by AN927. The 1-wire bus is implemented in the ow(4) device, which implements the own(9) interface (n for network, the layer described in the AN927). The presentation layer and above is the responsibility of the client device drivers to implement. Client drivers may only call the own(9) interface. The ow(4) driver calls the owll(9) interface and implements the own(9). $FreeBSD$