From patchwork Fri Jan 8 20:39:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bhaumik Bhatt X-Patchwork-Id: 359134 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=ham 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 14FC7C433E0 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 DA67A23A7F for ; Fri, 8 Jan 2021 20:42:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729202AbhAHUlf (ORCPT ); Fri, 8 Jan 2021 15:41:35 -0500 Received: from so254-31.mailgun.net ([198.61.254.31]:28801 "EHLO so254-31.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729580AbhAHUlJ (ORCPT ); Fri, 8 Jan 2021 15:41:09 -0500 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1610138448; h=References: In-Reply-To: Message-Id: Date: Subject: Cc: To: From: Sender; bh=Ro4Dwg1XTjV6jGELfcYjo/T5Ewp910MycYlNrYrqSZk=; b=QPu550Vosop8jEu71//USriHtOplOdB0ksqbbY/BBaQ1ALoP9hevuoCDQLhMjrhph8UkTM4p Z9yVL9JALtw/f/yXdAKRfUlNvQlYAL0Wt1nhLZK1hyM/Nfd55wkruJ7ocJEGBQe4qZYq6gN+ XlYnYklfX/1c4+N4Ix6mxzHd++Y= X-Mailgun-Sending-Ip: 198.61.254.31 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-n05.prod.us-east-1.postgun.com with SMTP id 5ff8c32a8fb3cda82fd38148 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Fri, 08 Jan 2021 20:40:10 GMT Sender: bbhatt=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id C75F7C433CA; Fri, 8 Jan 2021 20:40:09 +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 1B225C433C6; Fri, 8 Jan 2021 20:40:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1B225C433C6 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 8/8] bus: mhi: Improve documentation on channel transfer setup APIs Date: Fri, 8 Jan 2021 12:39:56 -0800 Message-Id: <1610138396-25811-9-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 The mhi_prepare_for_transfer() and mhi_unprepare_from_transfer() APIs could use better explanation, especially with the addition of two new APIs to start and stop the transfers on channels. Add better set of information for those APIs. Signed-off-by: Bhaumik Bhatt Reviewed-by: Hemant Kumar --- include/linux/mhi.h | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/include/linux/mhi.h b/include/linux/mhi.h index b5e11ba..94c5075 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -703,13 +703,35 @@ int mhi_device_get_sync(struct mhi_device *mhi_dev); void mhi_device_put(struct mhi_device *mhi_dev); /** - * mhi_prepare_for_transfer - Setup channel for data transfer + * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer. + * Allocate and initialize the channel context and + * also issue the START channel command to both + * channels. Channels can be started only if both + * host and device execution environments match and + * channels are in a DISABLED state. Calling the + * mhi_start_transfer() function is not required + * afterwards as channels are already started. This + * function also initializes the channel context + * whereas mhi_start_transfer() can only be used to + * issue the start channel command once the context + * is setup. * @mhi_dev: Device associated with the channels */ int mhi_prepare_for_transfer(struct mhi_device *mhi_dev); /** - * mhi_unprepare_from_transfer - Unprepare the channels + * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer. + * Issue the RESET channel command and let the + * device clean-up the context so no incoming + * transfers are seen on the host. Free memory + * associated with the context on host. If device + * is unresponsive, only perform a host side + * clean-up. Channels can be reset only if both + * host and device execution environments match + * and channels are in an ENABLED, STOPPED or + * SUSPENDED state. Calling mhi_stop_transfer() is + * not required before calling this function as it + * will only stop transfers, not reset channels. * @mhi_dev: Device associated with the channels */ void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);