From patchwork Mon Mar 1 16:10:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kiran Gunda X-Patchwork-Id: 388910 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=-16.8 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,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 B6682C43332 for ; Mon, 1 Mar 2021 16:15:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F50D64D90 for ; Mon, 1 Mar 2021 16:15:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237649AbhCAQPA (ORCPT ); Mon, 1 Mar 2021 11:15:00 -0500 Received: from z11.mailgun.us ([104.130.96.11]:31941 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237637AbhCAQMF (ORCPT ); Mon, 1 Mar 2021 11:12:05 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1614615086; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=d2M7jL2ITNFrQj2XHMVqUr+DoAAmOGNM+DSXrrc8dwI=; b=VYR+syYtwBckxgLnBgneToPMjS8Xqfw2CLde+wO302ugLwCGnc2/8+zb6FtsfNOzRa4qHcvM +8HVhJzGk3Ab9nvSFy42NoG9k7EUCVB4JNZTJMlK/zBLNRsHbBRcOMrxdnDK1ETOpNwwKT8D J14XYtsouox7bDqB+PrJe3dW0Og= X-Mailgun-Sending-Ip: 104.130.96.11 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-n03.prod.us-east-1.postgun.com with SMTP id 603d12131defdc70ae74cc71 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 01 Mar 2021 16:10:59 GMT Sender: kgunda=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C1563C43464; Mon, 1 Mar 2021 16:10:58 +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 EDE3FC43461; Mon, 1 Mar 2021 16:10:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org EDE3FC43461 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 V4 2/2] backlight: qcom-wled: Correct the sync_toggle sequence Date: Mon, 1 Mar 2021 21:40:30 +0530 Message-Id: <1614615030-12703-3-git-send-email-kgunda@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1614615030-12703-1-git-send-email-kgunda@codeaurora.org> References: <1614615030-12703-1-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 set-then-cleared. But, the FSC and brightness sync takes place when the sync bits are set (e.g. on a rising edge). 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 Reviewed-by: Daniel Thompson --- 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)