From patchwork Thu Mar 18 12:39:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kiran Gunda X-Patchwork-Id: 404285 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, 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 0D542C43381 for ; Thu, 18 Mar 2021 12:41:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF35264F77 for ; Thu, 18 Mar 2021 12:41:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231126AbhCRMlK (ORCPT ); Thu, 18 Mar 2021 08:41:10 -0400 Received: from a0.mail.mailgun.net ([198.61.254.59]:34965 "EHLO a0.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231288AbhCRMkr (ORCPT ); Thu, 18 Mar 2021 08:40:47 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1616071247; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=sXAGynqSLidMzR64Daok0xr8LMCoEyfeck8DvZcB7b4=; b=ovwi9Y2MoE5Mz0BQIpPQFEw7+3VhrDj9VYg0YsqSpYWC7eWpDKtStMRatZG2TmVu6SLEoaoU BBYKO57qUWA3flKqhLAlsB4X4tWhwVunrSHcsch5MjU7JSexbcCpqD+UKJL88qBZ0G9Ndgnw iqHJKTiKVGmI/e6DQoWNAqPERno= X-Mailgun-Sending-Ip: 198.61.254.59 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-n05.prod.us-east-1.postgun.com with SMTP id 60534a364db3bb68012ff842 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 18 Mar 2021 12:40:22 GMT Sender: kgunda=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id DA017C433ED; Thu, 18 Mar 2021 12:40:21 +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 AE246C43462; Thu, 18 Mar 2021 12:40:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org AE246C43462 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, phone-devel@vger.kernel.org, Andy Gross , linux-arm-msm@vger.kernel.org, linux-fbdev@vger.kernel.org Cc: Kiran Gunda Subject: [PATCH V5 2/2] backlight: qcom-wled: Correct the sync_toggle sequence Date: Thu, 18 Mar 2021 18:09:40 +0530 Message-Id: <1616071180-24493-3-git-send-email-kgunda@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1616071180-24493-1-git-send-email-kgunda@codeaurora.org> References: <1616071180-24493-1-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 e9fbe24..7c02f87 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->sink_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->sink_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)