From patchwork Wed Jun 8 08:41:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: cy_huang X-Patchwork-Id: 580437 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CE680C433EF for ; Wed, 8 Jun 2022 09:19:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234430AbiFHJTp (ORCPT ); Wed, 8 Jun 2022 05:19:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235289AbiFHJTP (ORCPT ); Wed, 8 Jun 2022 05:19:15 -0400 Received: from mail-oa1-x35.google.com (mail-oa1-x35.google.com [IPv6:2001:4860:4864:20::35]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F4272383C6; Wed, 8 Jun 2022 01:41:47 -0700 (PDT) Received: by mail-oa1-x35.google.com with SMTP id 586e51a60fabf-e656032735so26419869fac.0; Wed, 08 Jun 2022 01:41:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=SXmj6b+DkfLw5itmWk4/FOZXu0aiY0xTFwHQz3P20xg=; b=WdYBN8CGdrIXxQzK0GPeVgw2MzDlTQbjZImmiSCIjEzItPZCLwSrJunmeLbwAI5ikm 7UpERZ2fzajMjBN38noWZM/RUcDEMPoazkYxmDCZ/piF6SB6ltAhCk3muTBLBmfff+up 1ySlRhC1vAawc4shHJYJl8WtvyOFfF7pyOD2RMHst5fPRND+9bgFXKQhUs4eFuzF83pL TH7AybGjXUB/CPMHa+NdXiymNtTHvTNSi9Ff/1E1P5OvPjJCNNfhkrNJDXwi4zpqetk1 kyOe8mqAmriJNKLHM0imih+M6yAeZIA/mFxwR6SZyk+XLKohGvYt0P+D4aZX/5GXgoaR obRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=SXmj6b+DkfLw5itmWk4/FOZXu0aiY0xTFwHQz3P20xg=; b=XlmxD4uFJ3X5WhoTEiCn0+s+2JaYcVK42fDK6N5iKvZd1JWKt1YrU3TxMVvpMeOrLn RKXOiw+xJz+4CyKOZMPkkU+fWDex3qrmU3KTvul+oYv+LL2uRz0qONySfqRrTJ44+YvX lUTspEvTrAhb7BdVdF3Ji661bOyV6FylHqhxViOGts3cjHz9IjLWrTz+jb73uLR98sro yYwJ809nx35LNQjVsWy5yrEE7BKOsw4GObcTHX/KjK5DrRakHh0N1e/E35LSErsqAOT2 ilocDKkanXIUxXG54K7hcxLd8qw84qFZSBbHrHbRmm4NYPvMrxSWCtBuG8Akng07AWpC KYaw== X-Gm-Message-State: AOAM532tfNMeo1xHmQ71vS9vGTm5AKM/ljQoe6b2qWrX7GY14wlFx21J G98IA3RujJ1LfLERlTiWgQrE8g0XgTA0hA== X-Google-Smtp-Source: ABdhPJxAOK47geI2yEq8uUzL6jVlujBVSQkzoXkWwANZs743d3DkA34VEE/uGgrzp5MCNfVJU/Fzyg== X-Received: by 2002:a17:90a:4897:b0:1c7:5fce:cbcd with SMTP id b23-20020a17090a489700b001c75fcecbcdmr71830734pjh.45.1654677696141; Wed, 08 Jun 2022 01:41:36 -0700 (PDT) Received: from localhost.localdomain ([2402:7500:479:837b:38ad:1ae9:1239:b178]) by smtp.gmail.com with ESMTPSA id q4-20020a170902f34400b0015e8d4eb263sm13902217ple.173.2022.06.08.01.41.31 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Jun 2022 01:41:35 -0700 (PDT) From: cy_huang To: robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, lee.jones@linaro.org, daniel.thompson@linaro.org, jingoohan1@gmail.com Cc: pavel@ucw.cz, deller@gmx.de, cy_huang@richtek.com, lucas_tsai@richtek.com, devicetree@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] backlight: rt4831: Apply ocp level from devicetree Date: Wed, 8 Jun 2022 16:41:14 +0800 Message-Id: <1654677674-15417-3-git-send-email-u0084500@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1654677674-15417-1-git-send-email-u0084500@gmail.com> References: <1654677674-15417-1-git-send-email-u0084500@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org From: ChiYuan Huang Add 'richtek,bled-ocp-microamp' property parsing in device_property_init function. This value may configure prior to the kernel driver. If it's not specified in devicetree, keep the original setting. Else, use clamp to align the value in min/max range and also roundup to choose the best selector. Reported-by: Lucas Tsai Signed-off-by: ChiYuan Huang --- Since v2: - Prase the 'richtek,bled-ocp-microamp', clamp the value in min/max range, and roundup to get the best selector. --- drivers/video/backlight/rt4831-backlight.c | 33 +++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/video/backlight/rt4831-backlight.c b/drivers/video/backlight/rt4831-backlight.c index 42155c7..8c2001b 100644 --- a/drivers/video/backlight/rt4831-backlight.c +++ b/drivers/video/backlight/rt4831-backlight.c @@ -12,6 +12,7 @@ #define RT4831_REG_BLCFG 0x02 #define RT4831_REG_BLDIML 0x04 #define RT4831_REG_ENABLE 0x08 +#define RT4831_REG_BLOPT2 0x11 #define RT4831_BLMAX_BRIGHTNESS 2048 @@ -23,6 +24,11 @@ #define RT4831_BLDIML_MASK GENMASK(2, 0) #define RT4831_BLDIMH_MASK GENMASK(10, 3) #define RT4831_BLDIMH_SHIFT 3 +#define RT4831_BLOCP_MASK GENMASK(1, 0) + +#define RT4831_BLOCP_MINUA 900000 +#define RT4831_BLOCP_MAXUA 1800000 +#define RT4831_BLOCP_STEPUA 300000 struct rt4831_priv { struct device *dev; @@ -85,7 +91,7 @@ static int rt4831_parse_backlight_properties(struct rt4831_priv *priv, { struct device *dev = priv->dev; u8 propval; - u32 brightness; + u32 brightness, ocp_uA; unsigned int val = 0; int ret; @@ -120,6 +126,31 @@ static int rt4831_parse_backlight_properties(struct rt4831_priv *priv, if (ret) return ret; + /* + * This OCP level is used to protect and limit the inductor current. + * If inductor peak current reach the level, low-side MOSFET will be + * turned off. Meanwhile, the output channel current may be limited. + * To match the configured channel current, the inductor chosen must + * be higher than the OCP level. + * + * Not like the OVP level, the default 21V can be used in the most + * application. But if the chosen OCP level is smaller than needed, + * it will also affect the backlight channel output current to be + * smaller than the register setting. + */ + ret = device_property_read_u32(dev, "richtek,bled-ocp-microamp", + &ocp_uA); + if (!ret) { + ocp_uA = clamp_val(ocp_uA, RT4831_BLOCP_MINUA, + RT4831_BLOCP_MAXUA); + val = roundup(ocp_uA - RT4831_BLOCP_MINUA, + RT4831_BLOCP_STEPUA); + ret = regmap_update_bits(priv->regmap, RT4831_REG_BLOPT2, + RT4831_BLOCP_MASK, val); + if (ret) + return ret; + } + ret = device_property_read_u8(dev, "richtek,channel-use", &propval); if (ret) { dev_err(dev, "richtek,channel-use DT property missing\n");