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

From: Quentin Schulz
Date: Thu Sep 26 2024 - 07:24:44 EST


Hi Jakob,

On 2/1/24 1:44 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:

echo enabled > /sys/devices/platform/attiny-updi-gate-regulator/state


CONFIG_REGULATOR_USERSPACE_CONSUMER needs to be enabled for this to work. Just putting this here as I had forgotten and was wondering why this sysfs file wasn't available to me :)

Signed-off-by: Jakob Unterwurzacher <jakob.unterwurzacher@xxxxxxxxxxxxxxxxxxxxx>

I finally have access to some HW to test this, and therefore can give my:

Tested-by: Quentin Schulz <quentin.schulz@xxxxxxxxx>

---
arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
index dec29a75d361..1f7f4b2ea66a 100644
--- a/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
+++ b/arch/arm64/boot/dts/rockchip/px30-ringneck.dtsi
@@ -15,6 +15,12 @@ aliases {
rtc1 = &rk809;
};
+ /* allows userspace to control the gate of the ATtiny UPDI pass FET via sysfs */
+ attiny-updi-gate-regulator {
+ compatible = "regulator-output";
+ vout-supply = <&vg_attiny_updi>;
+ };
+
emmc_pwrseq: emmc-pwrseq {
compatible = "mmc-pwrseq-emmc";
pinctrl-0 = <&emmc_reset>;
@@ -146,6 +152,7 @@ rk809: pmic@20 {
vcc5-supply = <&vcc_3v3>;
vcc6-supply = <&vcc_3v3>;
vcc7-supply = <&vcc_3v3>;
+ vcc8-supply = <&vcc5v0_sys>;

According to the schematics, vcc8 is routed to SWITCH_REG2 and not SWITCH_REG1, which is fed vcc9. Even more so, vcc8 on the PMIC isn't actually routed.

I therefore think we can simply remove this line here.

@Jakob, do you agree? Can you send a v2 if so?

Cheers,
Quentin