Re: [PATCH v3 4/4] arm64: dts: rockchip: Add devicetree for Pine64 PineTab2

From: Manuel Traut <manut@mecka.net>
To: "Ondřej Jirman" <megi@xff.cz>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Jessica Zhang" <quic_jesszhan@quicinc.com>,
	"Sam Ravnborg" <sam@ravnborg.org>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Maxime Ripard" <mripard@kernel.org>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Sandy Huang" <hjc@rock-chips.com>,
	"Mark Yao" <markyao0591@gmail.com>,
	"Diederik de Haas" <didi.debian@cknow.org>,
	Segfault <awarnecke002@hotmail.com>,
	"Arnaud Ferraris" <aferraris@debian.org>,
	Danct12 <danct12@riseup.net>,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org
Subject: Re: [PATCH v3 4/4] arm64: dts: rockchip: Add devicetree for Pine64 PineTab2
Date: Fri, 26 Jan 2024 21:30:18 +0100	[thread overview]
Message-ID: <ZbQWWp3nmorbEVFl@mecka.net> (raw)
In-Reply-To: <elumjkchw5m6rcb73l4ouemjgk7nsgkeu576ybbkc5nbvcpiyi@txkepy7wqops>

Hello Ondřej,

On Fri, Jan 05, 2024 at 05:48:46PM +0100, Ondřej Jirman wrote:
> On Fri, Jan 05, 2024 at 05:11:03PM +0100, Manuel Traut wrote:
> > On Wed, Jan 03, 2024 at 10:42:54AM +0100, Ondřej Jirman wrote:
> > > Hello Manuel,
> > > 
> > > a few more things I noticed:
> > > 
> > > On Tue, Jan 02, 2024 at 05:15:47PM +0100, Manuel Traut wrote:
> > > > From: Alexander Warnecke <awarnecke002@hotmail.com>
> > > > 
> > > > +	leds {
> > > > +		compatible = "gpio-leds";
> > > > +
> > > > +		pinctrl-names = "default";
> > > > +		pinctrl-0 = <&flash_led_en_h>;
> > > > +
> > > > +		led-0 {
> > > > +			gpios = <&gpio4 RK_PA5 GPIO_ACTIVE_HIGH>;
> > > > +			color = <LED_COLOR_ID_WHITE>;
> > > > +			function = LED_FUNCTION_FLASH;
> > > > +		};
> > > 
> > > This LED is supplied by VCC5V_MIDU, so maybe this should be a regulator-led
> > > supplied by gpio (FLASH_LED_EN_H) controlled regulator-fixed named f_led which
> > > is in turn supplied by VCC5V_MIDU.
> > > 
> > > https://megous.com/dl/tmp/9bf0d85d78946b5e.png
> > 
> > regulator-leds are controlled by turning on or off the regulator. However
> > VCC5V_MIDU is also used by other devices (USB, HDMI, ..) so I guess this is
> > not what we want. I would keep it as is.
> 
> It's used by the LED. gpio-leds will not ensure it's on when you enable the LED.
> 
> In practice this may only come up if someone tries to save power by unloading
> dwc3 USB driver, when using PT2 outside of the keyboard case. Otherwise
> VCC5V_MIDU will be enabled by DWC3 driver's use of PHY API.
> 
> In any case, I'm not saying you should use VCC5V_MIDU directly in regulator-led,
> but as a vin-supply to a new regulator-fixed node (which would be describing
> this "fixed voltage regulator" https://megous.com/dl/tmp/cc65ec81ab9af163.png ).

Sorry for the late response, I was busy with other things in the last weeks.

I changed it to be a regulator led and will post a v4 soon.

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