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[23.128.96.18]) by mx.google.com with ESMTP id i22si95845ejr.184.2020.12.02.15.45.04; Wed, 02 Dec 2020 15:45:26 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@mg.codeaurora.org header.s=smtp header.b=BmsDQL9+; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387431AbgLBXmI (ORCPT + 99 others); Wed, 2 Dec 2020 18:42:08 -0500 Received: from a2.mail.mailgun.net ([198.61.254.61]:26585 "EHLO a2.mail.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728532AbgLBXmH (ORCPT ); Wed, 2 Dec 2020 18:42:07 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1606952508; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=oy/aThwyI7egpnediO0HIoxBAAw1Dyjel8E7NnExrYY=; b=BmsDQL9+3pqd1VyDGsedwsZnKL8dG0b+YOaKKUuC7Q1MREYhPbDBKWxemFbvt6IJzejF+BDa qf5apWr4cEcdQL3wcOSUbRlLYU2WZtNHwZ2g5uFtdINPIl6/qkAKggfcnxaxB2aeoeeW8OsC NOnMNbgTNsJZg4ZpQY95DC8kFDY= X-Mailgun-Sending-Ip: 198.61.254.61 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-n10.prod.us-west-2.postgun.com with SMTP id 5fc826030b1f6587dd17d758 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 02 Dec 2020 23:40:52 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id D9C3AC43460; Wed, 2 Dec 2020 23:40:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=ALL_TRUSTED,BAYES_00,SPF_FAIL autolearn=no autolearn_force=no version=3.4.0 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 BA524C43463; Wed, 2 Dec 2020 23:40:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org BA524C43463 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, hemantk@codeaurora.org Cc: linux-arm-msm@vger.kernel.org, loic.poulain@linaro.org, jhugo@codeaurora.org, linux-kernel@vger.kernel.org, Bhaumik Bhatt Subject: [PATCH v3 4/7] bus: mhi: core: Add support to stop or start channel data transfers Date: Wed, 2 Dec 2020 15:40:35 -0800 Message-Id: <1606952438-15321-5-git-send-email-bbhatt@codeaurora.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1606952438-15321-1-git-send-email-bbhatt@codeaurora.org> References: <1606952438-15321-1-git-send-email-bbhatt@codeaurora.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 | 41 +++++++++++++++++++++++++++++++++++++++++ include/linux/mhi.h | 19 +++++++++++++++++++ 2 files changed, 60 insertions(+) diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c index 4cc5ced..2e4b34a 100644 --- a/drivers/bus/mhi/core/main.c +++ b/drivers/bus/mhi/core/main.c @@ -1552,6 +1552,47 @@ 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 mhi_chan *mhi_chan; + 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 fail as client will reset + * both upon failure + */ + mutex_lock(&mhi_chan->mutex); + 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 aa9757e..35779a0 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -704,6 +704,25 @@ 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 -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project