From patchwork Thu Jun 13 08:39:39 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ludovic Desroches X-Patchwork-Id: 2714671 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 0C9589F3DD for ; Thu, 13 Jun 2013 08:42:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CDCBF2018B for ; Thu, 13 Jun 2013 08:42:51 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8D6B320175 for ; Thu, 13 Jun 2013 08:42:50 +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 1Un36K-0002qs-8X; Thu, 13 Jun 2013 08:41:49 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Un363-0005Th-Ra; Thu, 13 Jun 2013 08:41:31 +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 1Un361-0005SO-KN for linux-arm-kernel@lists.infradead.org; Thu, 13 Jun 2013 08:41:30 +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, 13 Jun 2013 10:41:04 +0200 From: To: , , , , Subject: [PATCH v3 2/2] at_hdmac: add FIFO configuration parameter to DMA DT binding Date: Thu, 13 Jun 2013 10:39:39 +0200 Message-ID: <1371112779-22738-3-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 1.7.11.3 In-Reply-To: <1371112779-22738-1-git-send-email-ludovic.desroches@atmel.com> References: <1371112779-22738-1-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-20130613_044129_950728_1165A062 X-CRM114-Status: GOOD ( 13.86 ) X-Spam-Score: -2.1 (--) Cc: 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 X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 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: Nicolas Ferre Acked-by: Jean-Christophe PLAGNIOL-VILLARD Signed-off-by: Ludovic Desroches --- .../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 6db5228..b7050a4 100644 --- a/drivers/dma/at_hdmac.c +++ b/drivers/dma/at_hdmac.c @@ -14,6 +14,7 @@ * found on AT91SAM9263. */ +#include #include #include #include @@ -1320,15 +1321,31 @@ 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_MSB(per_id) | ATC_DST_PER(per_id) + per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; + atslave->cfg |= ATC_DST_PER_MSB(per_id) | ATC_DST_PER(per_id) | ATC_SRC_PER_MSB(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);