From patchwork Thu May 30 16:08:23 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ludovic Desroches X-Patchwork-Id: 2637871 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id A5B4040077 for ; Thu, 30 May 2013 16:11:04 +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 1Ui5Q9-0007gG-Gc; Thu, 30 May 2013 16:09:46 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ui5Pn-0003t5-Bi; Thu, 30 May 2013 16:09:23 +0000 Received: from eusmtp01.atmel.com ([212.144.249.243]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Ui5PM-0003pT-HU for linux-arm-kernel@lists.infradead.org; Thu, 30 May 2013 16:08:58 +0000 Received: from ibiza.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.31) with Microsoft SMTP Server id 14.2.342.3; Thu, 30 May 2013 18:08:40 +0200 From: To: , Subject: [PATCH 3/3] at_hdmac: add FIFO configuration parameter to DMA DT binding Date: Thu, 30 May 2013 18:08:23 +0200 Message-ID: <1369930103-11963-4-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1369930103-11963-1-git-send-email-ludovic.desroches@atmel.com> References: <1369930103-11963-1-git-send-email-ludovic.desroches@atmel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130530_120856_848405_ABDEA6CC X-CRM114-Status: GOOD ( 14.33 ) X-Spam-Score: -3.0 (---) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-3.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -1.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: vinod.koul@intel.com, plagnioj@jcrosoft.com, Ludovic Desroches , nicolas.ferre@atmel.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 From: Ludovic Desroches For most devices the FIFO configuration is the same i.e. when half FIFO size is available/filled, a source/destination request is serviced. But USART devices have to do it when there is enough space/data available to perform a single AHB access so the ASAP configuration. Acked-by: Jean-Christophe PLAGNIOL-VILLARD Signed-off-by: Ludovic Desroches Acked-by: Nicolas Ferre --- .../devicetree/bindings/dma/atmel-dma.txt | 7 ++++-- drivers/dma/at_hdmac.c | 25 ++++++++++++++++++---- 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/dma/atmel-dma.txt b/Documentation/devicetree/bindings/dma/atmel-dma.txt index c80e8a3..c280a0e 100644 --- a/Documentation/devicetree/bindings/dma/atmel-dma.txt +++ b/Documentation/devicetree/bindings/dma/atmel-dma.txt @@ -24,8 +24,11 @@ The three cells in order are: 1. A phandle pointing to the DMA controller. 2. The memory interface (16 most significant bits), the peripheral interface (16 less significant bits). -3. The peripheral identifier for the hardware handshaking interface. The -identifier can be different for tx and rx. +3. Parameters for the at91 DMA configuration register which are device +dependant: + - bit 7-0: peripheral identifier for the hardware handshaking interface. The + identifier can be different for tx and rx. + - bit 11-8: FIFO configuration. 0 for half FIFO, 1 for ALAP, 1 for ASAP. Example: diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c index e923cda..bfd73e1 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -14,6 +14,7 @@ * found on AT91SAM9263. */ +#include #include #include #include @@ -1223,14 +1224,30 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, atslave = devm_kzalloc(&dmac_pdev->dev, sizeof(*atslave), GFP_KERNEL); if (!atslave) return NULL; + + atslave->cfg = ATC_DST_H2SEL_HW | ATC_SRC_H2SEL_HW; /* * We can fill both SRC_PER and DST_PER, one of these fields will be * ignored depending on DMA transfer direction. */ - per_id = dma_spec->args[1]; - atslave->cfg = ATC_FIFOCFG_HALFFIFO | ATC_DST_H2SEL_HW - | ATC_SRC_H2SEL_HW | ATC_DST_PER(per_id) - | ATC_SRC_PER(per_id); + per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; + atslave->cfg |= ATC_DST_PER(per_id) | ATC_SRC_PER(per_id); + /* + * We have to translate the value we get from the device tree since + * the half FIFO configuration value had to be 0 to keep backward + * compatibility. + */ + switch(dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { + case AT91_DMA_CFG_FIFOCFG_ALAP: + atslave->cfg |= ATC_FIFOCFG_LARGESTBURST; + break; + case AT91_DMA_CFG_FIFOCFG_ASAP: + atslave->cfg |= ATC_FIFOCFG_ENOUGHSPACE; + break; + case AT91_DMA_CFG_FIFOCFG_HALF: + default: + atslave->cfg |= ATC_FIFOCFG_HALFFIFO; + } atslave->dma_dev = &dmac_pdev->dev; chan = dma_request_channel(mask, at_dma_filter, atslave);