[PATCH v2] arm64: dts: rockchip: add attiny_rst_gate to Ringneck

[Heiko Stuebner]

Am Donnerstag, 26. September 2024, 15:24:03 CEST schrieb Quentin Schulz:
> Hi Jakob,
> 
> On 9/26/24 3:20 PM, Jakob Unterwurzacher wrote:
> > Ringneck v1.4 can contain (placement option) an on-board ATtiny
> > microcontroller instead of an STM32. In normal operation, this
> > is transparent to the software, as both microcontrollers emulate
> > the same ICs (amc6821 and isl1208).
> > 
> > For flashing the ATtiny, the SWITCH_REG1 regulator of the board's PMIC is
> > used to enable the ATtiny UPDI debug interface. If the STM32 is placed, or if
> > we are running on an older Ringneck revision, SWITCH_REG1 is not connected
> > and has no effect.
> > 
> > Add attiny-updi-gate-regulator so userspace can control it via sysfs
> > (needs CONFIG_REGULATOR_USERSPACE_CONSUMER):
> > 
> >    echo enabled > /sys/devices/platform/attiny-updi-gate-regulator/state
> > 
> > Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher at cherry.de>
> > Tested-by: Quentin Schulz <quentin.schulz at cherry.de>
> 
> Reviewed-by: Quentin Schulz <quentin.schulz at cherry.de>
> 
> This is a candidate for backporting to stable branches as well I assume, 
> @Heiko?

That is more on the darker side of gray here.

Looking at the stable-kernel-rules [0] the criteria is
  "It must either fix a real bug that bothers people or just add a device ID"

This change instead is adding a new feature to allow said flashing from a
running system.

sidenote: please don't post new versions as replies to previous versions,
as that confuses tooling a lot.

Heiko


[0] https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html