From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB505C433DF for ; Fri, 3 Jul 2020 19:48:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C4EEB208E4 for ; Fri, 3 Jul 2020 19:48:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=megous.com header.i=@megous.com header.b="CMPMnHsp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726877AbgGCTsu (ORCPT ); Fri, 3 Jul 2020 15:48:50 -0400 Received: from vps.xff.cz ([195.181.215.36]:47770 "EHLO vps.xff.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726560AbgGCTsr (ORCPT ); Fri, 3 Jul 2020 15:48:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=megous.com; s=mail; t=1593805725; bh=bIYOaQy4bpcqZdipw5TvtipwYQ+4P11t0efNzRjRNdM=; h=From:To:Cc:Subject:Date:References:From; b=CMPMnHspiUrG3aWVb9q7MdiQ8iekRSnBLoJC8rI3I41ZAO3NDq7J+HO85aRF0T9N5 J3klpwi0mNW42koI23eFm+7XxGvMbTjlVgxLskUfmcBQ6a6hoSpR+VGBCLXrC/6kCS rXlrHSe+bWyXCVIJGT90nqsoQ2xydooqlbpbe4zc= From: Ondrej Jirman To: linux-sunxi@googlegroups.com, Rob Herring , Maxime Ripard , Chen-Yu Tsai Cc: Ondrej Jirman , Mark Rutland , Samuel Holland , Martijn Braam , Luca Weiss , Bhushan Shah , Icenowy Zheng , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/3] arm64: dts: sun50i-pinephone: dldo4 must not be >= 1.8V Date: Fri, 3 Jul 2020 21:48:42 +0200 Message-Id: <20200703194842.111845-4-megous@megous.com> In-Reply-To: <20200703194842.111845-1-megous@megous.com> References: <20200703194842.111845-1-megous@megous.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some outputs from the RTL8723CS are connected to the PL port (BT_WAKE_AP), which runs at 1.8V. When BT_WAKE_AP is high, the PL pin this signal is connected to is overdriven, and the whole PL port's voltage rises somewhat. This results in changing voltage on the R_PWM pin (PL10), which is the cause for backlight flickering very noticeably when typing on a Bluetooth keyboard, because backlight intensity is highly sensitive to the voltage of the R_PWM pin. Limit the maximum WiFi/BT I/O voltage to 1.8V to avoid overdriving the PL port pins via BT and WiFi IO port signals. WiFi and BT functionality is unaffected by this change. This completely stops the backlight flicker when using bluetooth. Fixes: 91f480d40942 ("arm64: dts: allwinner: Add initial support for Pine64 PinePhone") Signed-off-by: Ondrej Jirman --- arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi index 904122711a89..25150aba749d 100644 --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pinephone.dtsi @@ -329,7 +329,7 @@ ®_dldo3 { ®_dldo4 { regulator-min-microvolt = <1800000>; - regulator-max-microvolt = <3300000>; + regulator-max-microvolt = <1800000>; regulator-name = "vcc-wifi-io"; }; -- 2.27.0