From patchwork Fri Jan 8 20:39:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 12007539 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 08823C433DB for ; Fri, 8 Jan 2021 20:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDBB723A68 for ; Fri, 8 Jan 2021 20:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729460AbhAHUlF (ORCPT ); Fri, 8 Jan 2021 15:41:05 -0500 Received: from m43-15.mailgun.net ([69.72.43.15]:32302 "EHLO m43-15.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729446AbhAHUlF (ORCPT ); Fri, 8 Jan 2021 15:41:05 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1610138444; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=V4rBMWOG/gFDcK+CfdId8OGWYl/QjbS13yiJIdqSMtM=; b=xMeG/deOxcuwdCAo4aMb+3p5pin1SSlIwc7LmjDe11+phCl6Ebmn1owBrnABpvuCtkYUV0vI HyWQ8noR7livdoOK0IkYlIIZrv5EfzTMx5npXY5Q/XfD0u/I+jEjx/eLTyI7CENWWlXaZO9R 1rCh6hCS7vAdL7Z897CHMSKv3+k= X-Mailgun-Sending-Ip: 69.72.43.15 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-east-1.postgun.com with SMTP id 5ff8c3294dcca1247573d955 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 08 Jan 2021 20:40:09 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 8D732C43464; Fri, 8 Jan 2021 20:40:08 +0000 (UTC) Received: from malabar-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: bbhatt) by smtp.codeaurora.org (Postfix) with ESMTPSA id 68F2FC433CA; Fri, 8 Jan 2021 20:40:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 68F2FC433CA 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=bbhatt@codeaurora.org From: Bhaumik Bhatt To: manivannan.sadhasivam@linaro.org Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org, jhugo@codeaurora.org, linux-kernel@vger.kernel.org, loic.poulain@linaro.org, Bhaumik Bhatt Subject: [RESEND PATCH v4 5/8] bus: mhi: core: Add support to stop or start channel data transfers Date: Fri, 8 Jan 2021 12:39:53 -0800 Message-Id: <1610138396-25811-6-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1610138396-25811-1-git-send-email-bbhatt@codeaurora.org> References: <1610138396-25811-1-git-send-email-bbhatt@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Some MHI client drivers may want to request a pause or halt of data transfer activity on their channels. Support for this does not exist and must be introduced, wherein the channel context is not reset or cleared but only the STOP channel command is issued. This would need to be paired with an API that allows resuming the data transfer activity on channels by use of the START channel command. This API assumes that the context information is already setup. Enable this using two new APIs, mhi_start_transfer() and mhi_stop_transfer(). Signed-off-by: Bhaumik Bhatt --- drivers/bus/mhi/core/main.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/mhi.h | 19 +++++++++++++++++ 2 files changed, 69 insertions(+) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index 081fdf0..a84e6aa 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1583,6 +1583,56 @@ void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev) } EXPORT_SYMBOL_GPL(mhi_unprepare_from_transfer); +static int mhi_update_transfer_state(struct mhi_device *mhi_dev, + enum mhi_ch_state_type to_state) +{ + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; + struct device *dev = &mhi_cntrl->mhi_dev->dev; + struct mhi_chan *mhi_chan; + struct mhi_chan_ctxt *chan_ctxt; + int dir, ret; + + for (dir = 0; dir < 2; dir++) { + mhi_chan = dir ? mhi_dev->ul_chan : mhi_dev->dl_chan; + + if (!mhi_chan) + continue; + + /* + * Bail out if one of the channels fails as client will reset + * both upon failure + */ + mutex_lock(&mhi_chan->mutex); + chan_ctxt = &mhi_cntrl->mhi_ctxt->chan_ctxt[mhi_chan->chan]; + if (!(chan_ctxt->chcfg & CHAN_CTX_CHSTATE_MASK)) { + mutex_unlock(&mhi_chan->mutex); + dev_err(dev, "Channel %s(%u) context not initialized\n", + mhi_chan->name, mhi_chan->chan); + return -EINVAL; + } + ret = mhi_update_channel_state(mhi_cntrl, mhi_chan, to_state); + if (ret) { + mutex_unlock(&mhi_chan->mutex); + return ret; + } + mutex_unlock(&mhi_chan->mutex); + } + + return 0; +} + +int mhi_stop_transfer(struct mhi_device *mhi_dev) +{ + return mhi_update_transfer_state(mhi_dev, MHI_CH_STATE_TYPE_STOP); +} +EXPORT_SYMBOL_GPL(mhi_stop_transfer); + +int mhi_start_transfer(struct mhi_device *mhi_dev) +{ + return mhi_update_transfer_state(mhi_dev, MHI_CH_STATE_TYPE_START); +} +EXPORT_SYMBOL_GPL(mhi_start_transfer); + int mhi_poll(struct mhi_device *mhi_dev, u32 budget) { struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl; diff --git a/include/linux/mhi.h b/include/linux/mhi.h index fe65554..b5e11ba 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -715,6 +715,25 @@ int mhi_prepare_for_transfer(struct mhi_device *mhi_dev); void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev); /** + * mhi_stop_transfer - Pauses ongoing channel activity by issuing the STOP + * channel command to both UL and DL channels. This command + * does not reset the channel context and the client drivers + * can issue mhi_start_transfer to resume activity. + * @mhi_dev: Device associated with the channels + */ +int mhi_stop_transfer(struct mhi_device *mhi_dev); + +/** + * mhi_start_transfer - Resumes channel activity by issuing the START channel + * command to both UL and DL channels. This command assumes + * the channel context is already setup and the client + * drivers can issue mhi_stop_transfer to pause activity if + * required. + * @mhi_dev: Device associated with the channels + */ +int mhi_start_transfer(struct mhi_device *mhi_dev); + +/** * mhi_poll - Poll for any available data in DL direction * @mhi_dev: Device associated with the channels * @budget: # of events to process