Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753299AbdCMOQx (ORCPT ); Mon, 13 Mar 2017 10:16:53 -0400 Received: from mail-wr0-f196.google.com ([209.85.128.196]:35231 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752618AbdCMOQW (ORCPT ); Mon, 13 Mar 2017 10:16:22 -0400 From: "M'boumba Cedric Madianga" To: vinod.koul@intel.com, robh+dt@kernel.org, mark.rutland@arm.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, dan.j.williams@intel.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: "M'boumba Cedric Madianga" Subject: [PATCH 2/5] dmaengine: Add STM32 DMAMUX driver Date: Mon, 13 Mar 2017 15:15:58 +0100 Message-Id: <1489414561-28912-3-git-send-email-cedric.madianga@gmail.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1489414561-28912-1-git-send-email-cedric.madianga@gmail.com> References: <1489414561-28912-1-git-send-email-cedric.madianga@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7813 Lines: 281 This patch implements the STM32 DMAMUX driver Signed-off-by: M'boumba Cedric Madianga --- drivers/dma/Kconfig | 9 ++ drivers/dma/Makefile | 1 + drivers/dma/stm32-dmamux.c | 231 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 241 insertions(+) create mode 100644 drivers/dma/stm32-dmamux.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index fc3435c..6ab80c9 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -461,6 +461,15 @@ config STM32_DMA If you have a board based on such a MCU and wish to use DMA say Y here. +config STM32_DMAMUX + bool "STMicroelectronics STM32 dma multiplexer support" + depends on STM32_DMA + help + Enable support for the on-chip DMA multiplexer on STMicroelectronics + STM32 MCUs. + If you have a board based on such a MCU and wish to use DMAMUX say Y + here. + config S3C24XX_DMAC bool "Samsung S3C24XX DMA support" depends on ARCH_S3C24XX || COMPILE_TEST diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 0b723e9..449c7a3 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -57,6 +57,7 @@ obj-$(CONFIG_RENESAS_DMA) += sh/ obj-$(CONFIG_SIRF_DMA) += sirf-dma.o obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o obj-$(CONFIG_STM32_DMA) += stm32-dma.o +obj-$(CONFIG_STM32_DMAMUX) += stm32-dmamux.o obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o diff --git a/drivers/dma/stm32-dmamux.c b/drivers/dma/stm32-dmamux.c new file mode 100644 index 0000000..3003546 --- /dev/null +++ b/drivers/dma/stm32-dmamux.c @@ -0,0 +1,231 @@ +/* + * DMA Router driver for STM32 DMA MUX + * + * Copyright (C) 2015 M'Boumba Cedric Madianga + * + * Based on LPC18xx/43xx DMA MUX and TI DMA XBAR + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define STM32_DMAMUX_CCR(x) (0x4 * (x)) +#define STM32_DMAMUX_MAX_CHANNELS 32 +#define STM32_DMAMUX_MAX_REQUESTS 255 + +struct stm32_dmamux { + u32 chan_id; + u32 request; + bool busy; +}; + +struct stm32_dmamux_data { + struct dma_router dmarouter; + struct stm32_dmamux *muxes; + struct clk *clk; + void __iomem *iomem; + u32 dmamux_requests; /* number of DMA requests connected to DMAMUX */ + u32 dmamux_channels; /* Number of DMA channels supported */ +}; + +static inline u32 stm32_dmamux_read(void __iomem *iomem, u32 reg) +{ + return readl_relaxed(iomem + reg); +} + +static inline void stm32_dmamux_write(void __iomem *iomem, u32 reg, u32 val) +{ + writel_relaxed(val, iomem + reg); +} + +static void stm32_dmamux_free(struct device *dev, void *route_data) +{ + struct stm32_dmamux_data *dmamux = dev_get_drvdata(dev); + struct stm32_dmamux *mux = route_data; + + /* Clear dma request for the right channel */ + stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0); + clk_disable(dmamux->clk); + mux->busy = false; + + dev_dbg(dev, "Unmapping dma-router%dchan%d (was routed to request%d)\n", + dev->id, mux->chan_id, mux->request); +} + +static void *stm32_dmamux_route_allocate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct platform_device *pdev = of_find_device_by_node(ofdma->of_node); + struct stm32_dmamux_data *dmamux = platform_get_drvdata(pdev); + struct stm32_dmamux *mux; + u32 chan_id; + int ret; + + if (dma_spec->args_count != 4) { + dev_err(&pdev->dev, "invalid number of dma mux args\n"); + return ERR_PTR(-EINVAL); + } + + if (dma_spec->args[0] >= dmamux->dmamux_channels) { + dev_err(&pdev->dev, "invalid channel id: %d\n", + dma_spec->args[0]); + return ERR_PTR(-EINVAL); + } + + if (dma_spec->args[1] > dmamux->dmamux_requests) { + dev_err(&pdev->dev, "invalid mux request number: %d\n", + dma_spec->args[1]); + return ERR_PTR(-EINVAL); + } + + /* The of_node_put() will be done in of_dma_router_xlate function */ + dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0); + if (!dma_spec->np) { + dev_err(&pdev->dev, "can't get dma master\n"); + return ERR_PTR(-EINVAL); + } + + chan_id = dma_spec->args[0]; + mux = &dmamux->muxes[chan_id]; + mux->chan_id = chan_id; + mux->request = dma_spec->args[1]; + + if (mux->busy) { + dev_err(&pdev->dev, "dma channel %d busy with request %d\n", + chan_id, mux->request); + return ERR_PTR(-EBUSY); + } + + ret = clk_enable(dmamux->clk); + if (ret < 0) { + dev_err(&pdev->dev, "clk_enable failed: %d\n", ret); + return ERR_PTR(ret); + } + + stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), + mux->request); + mux->busy = true; + + dev_dbg(&pdev->dev, "Mapping dma-router%dchan%d to request%d\n", + pdev->dev.id, mux->chan_id, mux->request); + + return mux; +} + +static int stm32_dmamux_probe(struct platform_device *pdev) +{ + struct device_node *dma_node, *node = pdev->dev.of_node; + struct stm32_dmamux_data *dmamux; + struct reset_control *rst; + struct resource *res; + int ret; + + if (!node) + return -ENODEV; + + dmamux = devm_kzalloc(&pdev->dev, sizeof(struct stm32_dmamux_data), + GFP_KERNEL); + if (!dmamux) + return -ENOMEM; + + dma_node = of_parse_phandle(node, "dma-masters", 0); + if (!dma_node) { + dev_err(&pdev->dev, "Can't get DMA master node\n"); + return -ENODEV; + } + of_node_put(dma_node); + + ret = of_property_read_u32(node, "dma-channels", + &dmamux->dmamux_channels); + if (ret) + dmamux->dmamux_channels = STM32_DMAMUX_MAX_CHANNELS; + + ret = of_property_read_u32(node, "dma-requests", + &dmamux->dmamux_requests); + if (ret) + dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + dmamux->iomem = devm_ioremap_resource(&pdev->dev, res); + if (!dmamux->iomem) + return -ENOMEM; + + dmamux->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dmamux->clk)) { + dev_err(&pdev->dev, "Missing controller clock\n"); + return PTR_ERR(dmamux->clk); + } + ret = clk_prepare(dmamux->clk); + if (ret < 0) { + dev_err(&pdev->dev, "clk_prep failed: %d\n", ret); + return ret; + } + + dmamux->muxes = devm_kcalloc(&pdev->dev, dmamux->dmamux_channels, + sizeof(struct stm32_dmamux), + GFP_KERNEL); + if (!dmamux->muxes) + return -ENOMEM; + + rst = devm_reset_control_get(&pdev->dev, NULL); + if (!IS_ERR(rst)) { + ret = clk_enable(dmamux->clk); + if (ret < 0) { + dev_err(&pdev->dev, "clk_enable failed: %d\n", ret); + return ret; + } + reset_control_assert(rst); + udelay(2); + reset_control_deassert(rst); + clk_disable(dmamux->clk); + } + + dmamux->dmarouter.dev = &pdev->dev; + dmamux->dmarouter.route_free = stm32_dmamux_free; + platform_set_drvdata(pdev, dmamux); + + ret = of_dma_router_register(node, stm32_dmamux_route_allocate, + &dmamux->dmarouter); + if (ret < 0) { + dev_err(&pdev->dev, + "STM32 DMAMUX DMA OF registration failed %d\n", ret); + return ret; + } + + dev_info(&pdev->dev, "STM32 DMAMUX driver registered\n"); + + return 0; +} + +static const struct of_device_id stm32_dmamux_match[] = { + { .compatible = "st,stm32-dmamux" }, + {}, +}; + +static struct platform_driver stm32_dmamux_driver = { + .probe = stm32_dmamux_probe, + .driver = { + .name = "stm32-dmamux", + .of_match_table = stm32_dmamux_match, + }, +}; + +static int __init stm32_dmamux_init(void) +{ + return platform_driver_register(&stm32_dmamux_driver); +} +arch_initcall(stm32_dmamux_init); -- 1.9.1