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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no 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 8F4A6C433ED for ; Wed, 28 Apr 2021 18:49:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41ED16143D for ; Wed, 28 Apr 2021 18:49:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243753AbhD1Sua (ORCPT ); Wed, 28 Apr 2021 14:50:30 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:32276 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240641AbhD1Su2 (ORCPT ); Wed, 28 Apr 2021 14:50:28 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1619635783; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=N/dajtlHUGmV0bs/qmyBU9Z9YVX9qd8QVrSfTOAJZuY=; b=CkfXab7hFZr1dp4oOF80QERTa22TemOu+r/f3vMcNqekTugXhigw8JhUfYByjQ/qPmsVBYfB OIZtJo3Q694cGJEcodJs7v3JJy+sw7PslrVqifxnn1oNN6t1xuKncKyu89/niHmQjCrZa1Zf cFAGnMSXqlWFPgU4sAADi/F/jck= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyI1MzIzYiIsICJsaW51eC1hcm0tbXNtQHZnZXIua2VybmVsLm9yZyIsICJiZTllNGEiXQ== Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n07.prod.us-west-2.postgun.com with SMTP id 6089ae462cc44d3aea5e1c16 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 28 Apr 2021 18:49:42 GMT Sender: subbaram=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 1E7C1C4338A; Wed, 28 Apr 2021 18:49:42 +0000 (UTC) Received: from subbaram-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: subbaram) by smtp.codeaurora.org (Postfix) with ESMTPSA id 16B83C433F1; Wed, 28 Apr 2021 18:49:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 16B83C433F1 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=subbaram@codeaurora.org From: Subbaraman Narayanamurthy To: bjorn.andersson@linaro.org Cc: aghayal@codeaurora.org, collinsd@codeaurora.org, fenglinw@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, subbaram@codeaurora.org Subject: Re: [PATCH 0/2] Add QCOM PMIC PWM driver Date: Wed, 28 Apr 2021 11:49:37 -0700 Message-Id: <1619635777-2872-1-git-send-email-subbaram@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <20210428155422.GL1908499@yoga> References: <20210428155422.GL1908499@yoga> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org >> Add PWM driver to support PWM modules inside QCOM PMIC chips which are accessed >> through SPMI bus. Normally, there would be multiple PWM modules with adjacent >> address spaces present in one PMIC chip, and each PWM module has 0x100 size of >> address space. With this driver, a pwm_chip with multiple pwm_device individuals >> is created, and each pwm_device individual is corresponding to one PWM module. >> > Exposing this as individual pwm_chips will prevent us from enabling the > LED related use cases (patterns and multicolor) that most versions of > the hardware support. > I proposed [1] a while ago and think this is a better approach. I'll > take some time to respin this and send out the next version. > [1] https://lore.kernel.org/linux-arm-msm/20201021201224.3430546-1-bjorn.andersson@linaro.org/ Hi Bjorn, Yes, we came across this patch series but this driver (leds-qcom-lpg) is a combo one which provides support only for RGB LEDs (or TRI_LED module) along with PWM/LPG channels allocated for it. Say, if we've additional PWM channels on the same PMIC (that provides user-interface support) or another PMIC (non user-interface) that has multiple PWM channels that are not used for LED notifications, it would be good to have a separate PWM driver to support such channels IMHO. There are couple of use cases we've come across recently. 1. Using a PWM channel for controlling external LCD backlight controller 2. Using a PWM channel for controlling a haptics actuator Thanks, Subbaraman -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.