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=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 4E926C4332B for ; Wed, 10 Mar 2021 18:58:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 13B0964FDA for ; Wed, 10 Mar 2021 18:58:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233619AbhCJS5w (ORCPT ); Wed, 10 Mar 2021 13:57:52 -0500 Received: from z11.mailgun.us ([104.130.96.11]:31495 "EHLO z11.mailgun.us" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231126AbhCJS5a (ORCPT ); Wed, 10 Mar 2021 13:57:30 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1615402650; h=Content-Transfer-Encoding: Content-Type: In-Reply-To: MIME-Version: Date: Message-ID: From: References: Cc: To: Subject: Sender; bh=17+EoLjmYv9h04ms2UQiOoHgGzuvEfwEX3JtQqJTGro=; b=YPkzHBFgNlVcDQEoayh1hb3R221pTLQy138FlMH5t2N5b+m92LjIdPuSDNHxjc1nxh9J+qPL F3IKUXveqzKfcCAHahaBEotqV14CNdbAF78h+p53G2c0F0XA/pQU//ya/3tdDqvos0w8VIF/ wIla+q17TSm47wHOr9eZW3lcgIE= X-Mailgun-Sending-Ip: 104.130.96.11 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd 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 60491691bb6300df75775108 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 10 Mar 2021 18:57:21 GMT Sender: jhugo=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 67C4AC433ED; Wed, 10 Mar 2021 18:57:21 +0000 (UTC) Received: from [10.226.59.216] (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: jhugo) by smtp.codeaurora.org (Postfix) with ESMTPSA id 4C96FC433C6; Wed, 10 Mar 2021 18:57:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 4C96FC433C6 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=jhugo@codeaurora.org Subject: Re: [PATCH v3 1/3] bus: mhi: core: Introduce internal register poll helper function To: Bhaumik Bhatt , manivannan.sadhasivam@linaro.org Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org, linux-kernel@vger.kernel.org, loic.poulain@linaro.org, carl.yin@quectel.com, naveen.kumar@quectel.com References: <1614138270-2374-1-git-send-email-bbhatt@codeaurora.org> <1614138270-2374-2-git-send-email-bbhatt@codeaurora.org> From: Jeffrey Hugo Message-ID: Date: Wed, 10 Mar 2021 11:57:19 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: <1614138270-2374-2-git-send-email-bbhatt@codeaurora.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/23/2021 8:44 PM, Bhaumik Bhatt wrote: > Introduce helper function to allow MHI core driver to poll for > a value in a register field. This helps reach a common path to > read and poll register values along with a retry time interval. > > Signed-off-by: Bhaumik Bhatt > --- > drivers/bus/mhi/core/internal.h | 3 +++ > drivers/bus/mhi/core/main.c | 23 +++++++++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h > index 6f80ec3..005286b 100644 > --- a/drivers/bus/mhi/core/internal.h > +++ b/drivers/bus/mhi/core/internal.h > @@ -643,6 +643,9 @@ int __must_check mhi_read_reg(struct mhi_controller *mhi_cntrl, > int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, > void __iomem *base, u32 offset, u32 mask, > u32 shift, u32 *out); > +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, > + void __iomem *base, u32 offset, u32 mask, > + u32 shift, u32 val, u32 delayus); > void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, > u32 offset, u32 val); > void mhi_write_reg_field(struct mhi_controller *mhi_cntrl, void __iomem *base, > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c > index 4e0131b..249ae26 100644 > --- a/drivers/bus/mhi/core/main.c > +++ b/drivers/bus/mhi/core/main.c > @@ -4,6 +4,7 @@ > * > */ > > +#include > #include > #include > #include > @@ -37,6 +38,28 @@ int __must_check mhi_read_reg_field(struct mhi_controller *mhi_cntrl, > return 0; > } > > +int __must_check mhi_poll_reg_field(struct mhi_controller *mhi_cntrl, > + void __iomem *base, u32 offset, > + u32 mask, u32 shift, u32 val, u32 delayus) > +{ > + int ret = -ENOENT; > + u32 out, retry = (mhi_cntrl->timeout_ms * 1000) / delayus; > + > + while (retry--) { > + ret = mhi_read_reg_field(mhi_cntrl, base, offset, mask, shift, > + &out); > + if (ret) > + return -EIO; I generally dislike recoding return codes. Do you believe it adds value here? I'm concerned that if I'm debugging an error, I'll get EIO, which I trace to here, but then I don't know what the actual error from mhi_read_reg_field() was. > + > + if (out == val) > + return 0; > + > + udelay(delayus); > + } > + > + return ret; > +} > + > void mhi_write_reg(struct mhi_controller *mhi_cntrl, void __iomem *base, > u32 offset, u32 val) > { > -- Jeffrey Hugo Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.