From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id ADF5C38910E; Wed, 29 Jul 2026 14:46:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785336417; cv=none; b=uwcu5kvBGjL4rqLcfJJu5mVolL77jyNV1VgvBaMDk04U7Aj/je9RPREbOHvtdxAWja+vi2OEJN4ncYcqS8A7SfkpJRHtfMgeePnr9yZXBvUJN06+2CAp/7+OyLU/h6IMoQEVi+UBASdp/Fz0g0ephSXelYgntEV/eZu+RUHw/Z0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785336417; c=relaxed/simple; bh=ac5MqdTH/iMPTH0Pd2RDhWIfUJ0atyomKfgvP0KD3Lc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LzIJ7lQ8Sh1deSFTswoswH6EGSMOsWC3ccgdsOVW4g/eqWnGascAmO80f/bPWD0OCmCjYfGqFcidpLpJBIIBjv0MUdMopwtL87/hSyxDdq2JoSNp5GVzelDYUe7ZcBhEEH0sXE+T6heyeQH2FZBLOsYuctlzl58bR96ffx2nQaI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=c2Iwj9ry; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="c2Iwj9ry" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To; bh=zJcsJ8fR+ulIwIiOMxrp3nSK2qIbFs2gb9tc6WLrzyQ=; b=c2Iwj9ryzc7uaSSy6XQOv58vFx ysJ3eLDDGkq65DzSjVvj1Lxj02XFVF/lGve/vr7WU6/lgoXvyTVX6bTWnHP5RjZJzMWT18EeK8kyK whKrhnj8Z9zR3AbSk0ppWJvyS3roCfMvyeSaqqiJS9meUURiohi99+AWgqe5+NpPwm2S1qcvclOg7 uEEDgHQiYrLDspUjMEc6rFFnnknWPy47yCLvkNzoyDxmzsgnNsnVKHjIqPixQGggrwm7RMm+L9CEF e6KoB5ZwPHLjyzQOuqZSp7KIdMYsYConi4zPod81125RGDJ7MHqXHggALLhACVLFmo9Dy46bxkxYw YbPO3r4w==; From: Heiko =?UTF-8?B?U3TDvGJuZXI=?= To: Alexey Charkov Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, Nicolas Frattaroli Subject: Re: [PATCH] arm64: dts: rockchip: Add DSI LCD display on rk3576-evb1 Date: Wed, 29 Jul 2026 16:46:45 +0200 Message-ID: <29759328.czjnFlTdjD@diego> In-Reply-To: <12339028.CDJkKcVGEf@phil> References: <20250925-rk3576-evb1-dsi-v1-1-c76fc3740abc@gmail.com> <748fd61a-31fb-436f-b028-b47807a4860c@gmail.com> <12339028.CDJkKcVGEf@phil> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Am Montag, 20. Oktober 2025, 14:31:12 Mitteleurop=C3=A4ische Sommerzeit sch= rieb Heiko Stuebner: > Am Montag, 20. Oktober 2025, 10:50:58 Mitteleurop=C3=A4ische Sommerzeit s= chrieb Alexey Charkov: > >=20 > > On Mon, Oct 20, 2025 at 12:31=E2=80=AFPM Heiko Stuebner wrote: > > > > > > Am Montag, 20. Oktober 2025, 10:19:51 Mitteleurop=C3=A4ische Sommerze= it schrieb Alexey Charkov: > > > > On Thu, Sep 25, 2025 at 12:38=E2=80=AFAM Alexey Charkov wrote: > > > > > > > > > > Add support for the Rockchip W552793DBA-V10 LCD+touchscreen assem= bly which > > > > > comes physically attached to Rockchip RK3576 EVB1 boards. > > > > > > > > > > The display part is driven by the on-chip MIPI DSI controller, an= d the > > > > > touchscreen is connected over I2C. > > > > > > > > > > Signed-off-by: Alexey Charkov > > > > > --- > > > > > Note that backlight support is left out for now, as it depends on= PWM > > > > > support [0] which has not yet been merged. > > > > > > > > > > A workaround is simply `gpioset -c 0 13=3D1` to set the respectiv= e GPIO > > > > > pin high and thus to light up the display unconditionally. > > > > > > > > > > [0] https://lore.kernel.org/lkml/20250602-rk3576-pwm-v2-0-a6434b0= ce60c@collabora.com/ > > > > > --- > > > > > arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts | 89 ++++++++++= ++++++++++++++ > > > > > 1 file changed, 89 insertions(+) > > > > > > > > Hi Heiko, > > > > > > > > Any thoughts about this one? Can we perhaps get it merged for -next? > > > > > > Does the gpio-backlight work on that device? > > > That would make the gpioset hack unnecessary. > >=20 > > I've got a local patch using pwm-gpio and pwm-backlight as a stop-gap=20 > > solution, but I don't think it's worth merging upstream, because the=20 > > backlight is supposed to be driven by the hardware PWM on the same pin= =20 > > (not bit-banging the GPIO line). After all, Nicolas has been working on= =20 > > adding a proper hardware PWM driver for RK3576. > >=20 > > The display itself works without PWM support, and so does the touchscre= en. >=20 > Right now, I don't think we have an actual timeline if/when Nicolas will > be able to work on the pwm again. So my idea was if we want to > integrate the baclight as you described below, to have an actual usable > display and then when the new pwm has landed switch over to that one? With the ELCE around the corner we're nearing the year-mark here ;-) (And I'm surprised, I remembered this pending patch) So how about integrating your gpio-pwm backlight for the time being? Or alternatively just going with a gpio-backlight, like the Anbernic Vita d= id: /* * LEDs and Backlights can be controlled as a PWM, but PWM * support is not yet available. */ gpio_backlight: backlight { compatible =3D "gpio-backlight"; gpios =3D <&gpio2 RK_PC4 GPIO_ACTIVE_HIGH>; pinctrl-0 =3D <&led_backlight_h>; pinctrl-names =3D "default"; }; DSI without backlight is a quite black screen, which I'd call non-working still, so would require some form of backlight. Heiko > > My temp patch goes like this: > >=20 > > --- > > arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts | 15 +++++++++++++++ > > 1 file changed, 15 insertions(+) > >=20 > > diff --git a/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts=20 > > b/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts > > index f20cd6f2c079..5c27fff03569 100644 > > --- a/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts > > +++ b/arch/arm64/boot/dts/rockchip/rk3576-evb1-v10.dts > > @@ -58,6 +58,14 @@ button-vol-up { > > }; > > }; > >=20 > > + backlight: backlight { > > + compatible =3D "pwm-backlight"; > > + brightness-levels =3D <20 220>; > > + default-brightness-level =3D <100>; > > + num-interpolated-steps =3D <200>; > > + pwms =3D <&lcd_bl_pwm 0 25000 0>; > > + }; > > + > > hdmi-con { > > compatible =3D "hdmi-connector"; > > type =3D "a"; > > @@ -78,6 +86,12 @@ work_led: led-0 { > > }; > > }; > >=20 > > + lcd_bl_pwm: pwm { > > + #pwm-cells =3D <3>; > > + compatible =3D "pwm-gpio"; > > + gpios =3D <&gpio0 RK_PB5 GPIO_ACTIVE_HIGH>; > > + }; > > + > > vbus5v0_typec: regulator-vbus5v0-typec { > > compatible =3D "regulator-fixed"; > > regulator-name =3D "vbus5v0_typec"; > > @@ -277,6 +291,7 @@ panel@0 { > > compatible =3D "wanchanglong,w552793baa", "raydium,rm67200"; > > reg =3D <0>; > >=20 > > + backlight =3D <&backlight>; > > iovcc-supply =3D <&vcc3v3_lcd_n>; > > reset-gpios =3D <&gpio3 RK_PB5 GPIO_ACTIVE_LOW>; > > vdd-supply =3D <&vcc3v3_lcd_n>; > >=20 >=20 >=20