Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751626AbdIQDUR (ORCPT ); Sat, 16 Sep 2017 23:20:17 -0400 Received: from mail-out-2.itc.rwth-aachen.de ([134.130.5.47]:6004 "EHLO mail-out-2.itc.rwth-aachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751551AbdIQDUN (ORCPT ); Sat, 16 Sep 2017 23:20:13 -0400 X-IronPort-AV: E=Sophos;i="5.42,405,1500933600"; d="scan'208";a="13727184" From: =?UTF-8?q?Stefan=20Br=C3=BCns?= To: CC: , , Vinod Koul , , , Maxime Ripard , Chen-Yu Tsai , Rob Herring , Code Kipper , Andre Przywara Subject: [PATCH v2 07/10] dmaengine: sun6i: Retrieve channel count/max request from devicetree Date: Sun, 17 Sep 2017 05:19:53 +0200 Message-ID: <20170917031956.28010-8-stefan.bruens@rwth-aachen.de> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20170917031956.28010-1-stefan.bruens@rwth-aachen.de> References: <20170917031956.28010-1-stefan.bruens@rwth-aachen.de> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [85.183.223.53] X-ClientProxiedBy: rwthex-w1-b.rwth-ad.de (2002:8682:1a9d::8682:1a9d) To rwthex-w1-a.rwth-ad.de (2002:8682:1a9c::8682:1a9c) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2738 Lines: 83 To avoid introduction of a new compatible for each small SoC/DMA controller variation, move the definition of the channel count to the devicetree. The number of vchans is no longer explicit, but limited by the highest port/DMA request number. The result is a slight overallocation for SoCs with a sparse port mapping. Signed-off-by: Stefan Brüns --- drivers/dma/sun6i-dma.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-) diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c index 245a147f718f..b5ecc97a0d5a 100644 --- a/drivers/dma/sun6i-dma.c +++ b/drivers/dma/sun6i-dma.c @@ -42,6 +42,9 @@ #define DMA_STAT 0x30 +/* Offset between DMA_IRQ_EN and DMA_IRQ_STAT limits number of channels */ +#define DMA_MAX_CHANNELS (DMA_IRQ_CHAN_NR * 0x10 / 4) + /* * sun8i specific registers */ @@ -65,7 +68,8 @@ #define DMA_CHAN_LLI_ADDR 0x08 #define DMA_CHAN_CUR_CFG 0x0c -#define DMA_CHAN_CFG_SRC_DRQ(x) ((x) & 0x1f) +#define DMA_CHAN_MAX_DRQ 0x1f +#define DMA_CHAN_CFG_SRC_DRQ(x) ((x) & DMA_CHAN_MAX_DRQ) #define DMA_CHAN_CFG_SRC_IO_MODE BIT(5) #define DMA_CHAN_CFG_SRC_LINEAR_MODE (0 << 5) #define DMA_CHAN_CFG_SRC_BURST_A31(x) (((x) & 0x3) << 7) @@ -1157,6 +1161,7 @@ MODULE_DEVICE_TABLE(of, sun6i_dma_match); static int sun6i_dma_probe(struct platform_device *pdev) { const struct of_device_id *device; + struct device_node *np = pdev->dev.of_node; struct sun6i_dma_dev *sdc; struct resource *res; int ret, i; @@ -1232,6 +1237,36 @@ static int sun6i_dma_probe(struct platform_device *pdev) sdc->num_vchans = sdc->cfg->nr_max_vchans; sdc->max_request = sdc->cfg->nr_max_requests; + ret = of_property_read_u32(np, "dma-channels", &sdc->num_pchans); + if (ret && !sdc->num_pchans) { + dev_err(&pdev->dev, "Can't get dma-channels.\n"); + return ret; + } + + if (sdc->num_pchans > DMA_MAX_CHANNELS) { + dev_err(&pdev->dev, "Number of dma-channels out of range.\n"); + return -EINVAL; + } + + ret = of_property_read_u32(np, "dma-requests", &sdc->max_request); + if (ret && !sdc->max_request) { + dev_info(&pdev->dev, "Missing dma-requests, using %u.\n", + DMA_CHAN_MAX_DRQ); + sdc->max_request = DMA_CHAN_MAX_DRQ; + } + + if (sdc->max_request > DMA_CHAN_MAX_DRQ) { + dev_err(&pdev->dev, "Value of dma-requests out of range.\n"); + return -EINVAL; + } + + /* + * If the number of vchans is not specified, derive it from the + * highest port number, at most one channel per port and direction. + */ + if (!sdc->num_vchans) + sdc->num_vchans = 2 * (sdc->max_request + 1); + sdc->pchans = devm_kcalloc(&pdev->dev, sdc->num_pchans, sizeof(struct sun6i_pchan), GFP_KERNEL); if (!sdc->pchans) -- 2.14.1