From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759129AbdAEGLD (ORCPT ); Thu, 5 Jan 2017 01:11:03 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:51314 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754288AbdAEGKL (ORCPT ); Thu, 5 Jan 2017 01:10:11 -0500 From: Jiada Wang To: , , CC: , , , Subject: [PATCH 1/1] spi: imx: support to set watermark level via DTS Date: Thu, 5 Jan 2017 15:10:15 +0900 Message-ID: <20170105061015.7816-1-jiada_wang@mentor.com> X-Mailer: git-send-email 2.9.3 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Previously watermark level is configured to fifosize/2, DMA mode can be used only when transfer length can be divided by 'watermark level * bpw', which makes DMA mode not practical. This patch adds new DTS property 'dma-wml', user can configure DMA watermark level, by specify 'dma-wml' in corresponding ecspi node. Signed-off-by: Jiada Wang --- Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt | 2 ++ drivers/spi/spi-imx.c | 12 ++++++++++-- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt index 8bc95e2..1e9345f 100644 --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -19,6 +19,7 @@ See the clock consumer binding, - dmas: DMA specifiers for tx and rx dma. See the DMA client binding, Documentation/devicetree/bindings/dma/dma.txt - dma-names: DMA request names should include "tx" and "rx" if present. +- dma-wml: Specifies DMA watermark level Obsolete properties: - fsl,spi-num-chipselects : Contains the number of the chipselect @@ -35,4 +36,5 @@ ecspi@70010000 { <&gpio3 25 0>; /* GPIO3_25 */ dmas = <&sdma 3 7 1>, <&sdma 4 7 2>; dma-names = "rx", "tx"; + dma-wml = <16>; }; diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index deb782f..5c0ce19 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -929,8 +929,6 @@ static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, if (of_machine_is_compatible("fsl,imx6dl")) return 0; - spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2; - /* Prepare for TX DMA: */ master->dma_tx = dma_request_slave_channel_reason(dev, "tx"); if (IS_ERR(master->dma_tx)) { @@ -1155,6 +1153,7 @@ static int spi_imx_probe(struct platform_device *pdev) struct spi_imx_data *spi_imx; struct resource *res; int i, ret, irq; + u32 wml; if (!np && !mxc_platform_info) { dev_err(&pdev->dev, "can't get the platform data\n"); @@ -1177,6 +1176,15 @@ static int spi_imx_probe(struct platform_device *pdev) spi_imx->devtype_data = of_id ? of_id->data : (struct spi_imx_devtype_data *)pdev->id_entry->driver_data; + if (of_property_read_u32(np, "dma-wml", &wml) == 0) { + if (wml > spi_imx_get_fifosize(spi_imx) || wml == 0) { + dev_warn(&pdev->dev, "mis-configured dma-wml\n"); + spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2; + } else + spi_imx->wml = wml; + } else + spi_imx->wml = spi_imx_get_fifosize(spi_imx) / 2; + if (mxc_platform_info) { master->num_chipselect = mxc_platform_info->num_chipselect; master->cs_gpios = devm_kzalloc(&master->dev, -- 2.9.3