Update owc_gpiobus (one-wire over gpio) to the modern gpio_pin interface.

[• ian]

Summary

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.

[imp]

I'll take a look at this and make sure my setup still work w/minimum of hassle.

[• ian]

In D22710#496964, @imp wrote:

I'll take a look at this and make sure my setup still work w/minimum of hassle.

It should work with absolutely no changes at all to fdt data. If you have to change anything, let me know.

[zarychtam_plan-b.pwste.edu.pl]

Works fine for me on Raspberry Pi 2 running patched 13.0-CURRENT. Patch was applied on r355585

[• ian]

Update to incorporate change just committed to head that defers attachment of the ow bus until after interrupts are working.

[zarychtam_plan-b.pwste.edu.pl]

This patch allows to seamlessly get ow_tem(4) working over 1-wire bus on boards, where building custom overlay is more problematic like for Pine64-LTS.
For this board only adding a few lines to /boot/loader.conf is required:

hint.owc.0.at=gpiobus0
hint.owc.0.pin_list=18
ow_load="YES"
owc_load="YES"
ow_temp_load="YES"

Thank you for such a nice Christmas gift Ian !

[imp]

This looks good me, but time has gotten away from me to set it up.