From patchwork Thu Mar 13 09:18:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Ujfalusi X-Patchwork-Id: 3825051 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id F1DA2BF540 for ; Thu, 13 Mar 2014 11:04:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 22A59201BA for ; Thu, 13 Mar 2014 11:04:53 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DD2E02018A for ; Thu, 13 Mar 2014 11:04:51 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WO1qE-0001JJ-54; Thu, 13 Mar 2014 09:22:19 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WO1pG-0000s8-L5; Thu, 13 Mar 2014 09:21:18 +0000 Received: from devils.ext.ti.com ([198.47.26.153]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WO1nb-0000ZZ-8n for linux-arm-kernel@lists.infradead.org; Thu, 13 Mar 2014 09:19:37 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id s2D9J9qS004668; Thu, 13 Mar 2014 04:19:09 -0500 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id s2D9J8w5031351; Thu, 13 Mar 2014 04:19:08 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.174.1; Thu, 13 Mar 2014 04:19:08 -0500 Received: from dflp32.itg.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id s2D9Ifhb005531; Thu, 13 Mar 2014 04:19:05 -0500 From: Peter Ujfalusi To: , , , , Subject: [PATCH 06/18] arm: common: edma: API to request non default queue for a channel Date: Thu, 13 Mar 2014 11:18:28 +0200 Message-ID: <1394702320-21743-7-git-send-email-peter.ujfalusi@ti.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1394702320-21743-1-git-send-email-peter.ujfalusi@ti.com> References: <1394702320-21743-1-git-send-email-peter.ujfalusi@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140313_051935_484244_3C44FF6A X-CRM114-Status: GOOD ( 14.96 ) X-Spam-Score: -6.9 (------) Cc: davinci-linux-open-source@linux.davincidsp.com, joelf@ti.com, nsekhar@ti.com, Liam Girdwood , Jyri Sarha , Tony Lindgren , Mark Brown , mporter@linaro.org, dan.j.williams@intel.com, vinod.koul@intel.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When using eDMA3 via dmaengine all dma channels will use the default queue. Since during request time we do not have means to change this it need to be done later, before the DMA has been started. With the added function it is possible to move the channel to a non default queue if it is possible, otherwise (when only one EQ/TC is available for the CC) the default queue is going to be used. For example: For optimal system performance the audio (cyclic) DMA should be placed to a separate queue which is different than what the rest of the system is using. Signed-off-by: Peter Ujfalusi --- arch/arm/common/edma.c | 27 +++++++++++++++++++++++++++ include/linux/platform_data/edma.h | 2 ++ 2 files changed, 29 insertions(+) diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c index be267b2080be..eaf6dd19f082 100644 --- a/arch/arm/common/edma.c +++ b/arch/arm/common/edma.c @@ -712,6 +712,33 @@ int edma_alloc_channel(int channel, } EXPORT_SYMBOL(edma_alloc_channel); +/** + * edma_request_non_default_queue - try to map the channel to non default queue + * @channel: dma channel returned from edma_alloc_channel() + * + * For certain type of applications like audio it is preferred to not use the + * default event queue/tc to avoid eDMA caused latency. + * + * This function will iterate through the event queues available for the CC and + * picks the first EQ/TC which is not set as the default for the CC + */ +void edma_request_non_default_queue(int channel) +{ + unsigned ctlr = EDMA_CTLR(channel); + enum dma_event_q eventq_no = EVENTQ_DEFAULT; + int i; + + for (i = 0; i < edma_cc[ctlr]->num_tc; i++) { + if (i != edma_cc[ctlr]->default_queue) { + eventq_no = i; + break; + } + } + + channel = EDMA_CHAN_SLOT(channel); + map_dmach_queue(ctlr, channel, eventq_no); +} +EXPORT_SYMBOL(edma_request_non_default_queue); /** * edma_free_channel - deallocate DMA channel diff --git a/include/linux/platform_data/edma.h b/include/linux/platform_data/edma.h index 923f8a3e4ce0..5d0a1b98f205 100644 --- a/include/linux/platform_data/edma.h +++ b/include/linux/platform_data/edma.h @@ -117,6 +117,8 @@ int edma_alloc_channel(int channel, void *data, enum dma_event_q); void edma_free_channel(unsigned channel); +void edma_request_non_default_queue(int channel); + /* alloc/free parameter RAM slots */ int edma_alloc_slot(unsigned ctlr, int slot); void edma_free_slot(unsigned slot);