From patchwork Fri Feb 26 12:12:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kiran Gunda X-Patchwork-Id: 12106575 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=-16.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 34378C4321A for ; Fri, 26 Feb 2021 12:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 06ADB64ED2 for ; Fri, 26 Feb 2021 12:14:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229622AbhBZMOE (ORCPT ); Fri, 26 Feb 2021 07:14:04 -0500 Received: from m42-2.mailgun.net ([69.72.42.2]:42035 "EHLO m42-2.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230195AbhBZMNy (ORCPT ); Fri, 26 Feb 2021 07:13:54 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614341616; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=eu6z2kcT31mkhRofy2D9EtXByOz0EiNCdl00jqY/V+I=; b=Iw4v3yL6bNIjyEwZYCtj242MbPntIG6IRDdCsDB23v4/qLT3jwdPurdkZZ3kpi1PhLPNsYne PLu5kS9uNedyDjOM4cyTiP9beoy41NJ5Ku9nUgfgTMyepW1rg6l3hYR6E/Nhfh3NOIFO3nDS ySY/sMB/EmkLaDS6x0affTgrQh8= X-Mailgun-Sending-Ip: 69.72.42.2 X-Mailgun-Sid: WyI4YmIzMiIsICJsaW51eC1mYmRldkB2Z2VyLmtlcm5lbC5vcmciLCAiYmU5ZTRhIl0= Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 6038e5d0cc1f7d7e95ed4654 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 26 Feb 2021 12:13:04 GMT Sender: kgunda=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 77F56C433ED; Fri, 26 Feb 2021 12:13:04 +0000 (UTC) Received: from kgunda-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: kgunda) by smtp.codeaurora.org (Postfix) with ESMTPSA id 08297C433CA; Fri, 26 Feb 2021 12:12:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 08297C433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=kgunda@codeaurora.org From: Kiran Gunda To: bjorn.andersson@linaro.org, jingoohan1@gmail.com, lee.jones@linaro.org, b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, daniel.thompson@linaro.org, jacek.anaszewski@gmail.com, pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Andy Gross , linux-arm-msm@vger.kernel.org, linux-fbdev@vger.kernel.org Cc: phone-devel@vger.kernel.org, Kiran Gunda Subject: [PATCH V2 2/2] backlight: qcom-wled: Correct the sync_toggle sequence Date: Fri, 26 Feb 2021 17:42:24 +0530 Message-Id: <1614341544-5306-3-git-send-email-kgunda@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1614341544-5306-1-git-send-email-kgunda@codeaurora.org> References: <1614341544-5306-1-git-send-email-kgunda@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org As per the current implementation, after FSC (Full Scale Current) and brightness update the sync bits are transitioned from 1 to 0. But, the FSC and brightness sync takes place during a 0 to 1 transition of the sync bits. So the hardware team recommends a clear-then-set approach in order to guarantee such a transition regardless of the previous register state. Signed-off-by: Kiran Gunda --- drivers/video/backlight/qcom-wled.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c index aef52b9..19f83ac 100644 --- a/drivers/video/backlight/qcom-wled.c +++ b/drivers/video/backlight/qcom-wled.c @@ -337,13 +337,13 @@ static int wled3_sync_toggle(struct wled *wled) rc = regmap_update_bits(wled->regmap, wled->ctrl_addr + WLED3_SINK_REG_SYNC, - mask, mask); + mask, WLED3_SINK_REG_SYNC_CLEAR); if (rc < 0) return rc; rc = regmap_update_bits(wled->regmap, wled->ctrl_addr + WLED3_SINK_REG_SYNC, - mask, WLED3_SINK_REG_SYNC_CLEAR); + mask, mask); return rc; } @@ -353,17 +353,17 @@ static int wled5_mod_sync_toggle(struct wled *wled) int rc; u8 val; - val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT : - WLED5_SINK_REG_SYNC_MOD_B_BIT; rc = regmap_update_bits(wled->regmap, wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT, - WLED5_SINK_REG_SYNC_MASK, val); + WLED5_SINK_REG_SYNC_MASK, 0); if (rc < 0) return rc; + val = (wled->cfg.mod_sel == MOD_A) ? WLED5_SINK_REG_SYNC_MOD_A_BIT : + WLED5_SINK_REG_SYNC_MOD_B_BIT; return regmap_update_bits(wled->regmap, wled->sink_addr + WLED5_SINK_REG_MOD_SYNC_BIT, - WLED5_SINK_REG_SYNC_MASK, 0); + WLED5_SINK_REG_SYNC_MASK, val); } static int wled_ovp_fault_status(struct wled *wled, bool *fault_set)