From patchwork Thu Sep 21 15:29:19 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Yves MORDRET X-Patchwork-Id: 9964173 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 330036020C for ; Thu, 21 Sep 2017 15:41:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2152B291FC for ; Thu, 21 Sep 2017 15:41:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1611729213; Thu, 21 Sep 2017 15:41:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 32487291FC for ; Thu, 21 Sep 2017 15:41:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Cc:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Hiyqvi4uljGnYfz0iP8MOrecFiKze3sfEOmTLiQkN0U=; b=QqGUVN9e/0YSoy 7kb1YRaGkAgNvYq9xh3m5ztHx+Ti9GneX2rUKO4CWPuHR2ZbyWqnD6byo/XMx0gICGAFkr4qWm92u PlUV9qypKrOj+pZjj19TCzpLjIXDGozolEsv5m6NDNU7XZnhUWOp2xele5XGNVK4JL2/YoEeej78b JHIu2XQNaeDNElSkFs9y8m0hRwDPEsuxYw7pMH+DgyvA5F9MPwpRi2NL8dihUiODG/7uo6b8CMtl8 prO0nQy53+xC5q2ia4XK0Ia7kxJXe3NLubWmDXlpgaQUIFQFddrs0KLYGmpZftxD9zHkb9SgnELpc nWSVVswZcGSx0POGyOJw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dv3bd-0008H1-8E; Thu, 21 Sep 2017 15:41:37 +0000 Received: from mx07-00178001.pphosted.com ([62.209.51.94]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dv3R2-0003WZ-VF for linux-arm-kernel@lists.infradead.org; Thu, 21 Sep 2017 15:30:49 +0000 Received: from pps.filterd (m0046668.ppops.net [127.0.0.1]) by mx07-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v8LFTNfW012848; Thu, 21 Sep 2017 17:29:49 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com with ESMTP id 2d48cgayhg-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Thu, 21 Sep 2017 17:29:49 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 4FA4E34; Thu, 21 Sep 2017 15:29:49 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node2.st.com [10.75.127.14]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 1763029C1; Thu, 21 Sep 2017 15:29:49 +0000 (GMT) Received: from localhost (10.75.127.47) by SFHDAG5NODE2.st.com (10.75.127.14) with Microsoft SMTP Server (TLS) id 15.0.1178.4; Thu, 21 Sep 2017 17:29:48 +0200 From: Pierre-Yves MORDRET To: Vinod Koul , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre Torgue , Russell King , Dan Williams , "M'boumba Cedric Madianga" , Fabrice GASNIER , Herbert Xu , Fabien DESSENNE , Amelie Delaunay , Pierre-Yves MORDRET , , , , Subject: [PATCH v5 2/4] dmaengine: Add STM32 DMAMUX driver Date: Thu, 21 Sep 2017 17:29:19 +0200 Message-ID: <1506007761-11621-3-git-send-email-pierre-yves.mordret@st.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1506007761-11621-1-git-send-email-pierre-yves.mordret@st.com> References: <1506007761-11621-1-git-send-email-pierre-yves.mordret@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.47] X-ClientProxiedBy: SFHDAG8NODE2.st.com (10.75.127.23) To SFHDAG5NODE2.st.com (10.75.127.14) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-09-21_02:, , signatures=0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170921_083041_510215_414B77B1 X-CRM114-Status: GOOD ( 28.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 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-Virus-Scanned: ClamAV using ClamSMTP This patch implements the STM32 DMAMUX driver. The DMAMUX request multiplexer allows routing a DMA request line between the peripherals and the DMA controllers of the product. The routing function is ensured by a programmable multi-channel DMA request line multiplexer. Each channel selects a unique DMA request line, unconditionally or synchronously with events from its DMAMUX synchronization inputs. The DMAMUX may also be used as a DMA request generator from programmable events on its input trigger signals Signed-off-by: M'boumba Cedric Madianga Signed-off-by: Pierre-Yves MORDRET --- Version history: v5: * Set selected channel ID within a lock to avoid race condition. Release if any error occurs v4: * Get rid of st,dmamux property and custom API between STM32 DMAMUX and DMA. DMAMUX will read DMA masters from Device Tree from now on. Merely one DMAMUX node is needed now. * Only STM32 DMA are allowed to be connected onto DMAMUX * channelID is computed locally within the driver and crafted in dma_psec to be passed toward DMA master. DMAMUX router sorts out which DMA master will serve the request automatically. * This version forbids the use of DMA in standalone and DMAMUX at the same time : all clients need to be connected either on DMA or DMAMUX ; no mix up v3: * change compatible to st,stm32h7-dmamux to be mode SoC specific v2: * Dynamic channelID allocation. * Change of_property_... by device_property. * New clock management. * DMAMUX Configuration API. --- --- drivers/dma/Kconfig | 9 ++ drivers/dma/Makefile | 1 + drivers/dma/stm32-dmamux.c | 327 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 337 insertions(+) create mode 100644 drivers/dma/stm32-dmamux.c diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index fadc4d8..04e381b 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -483,6 +483,15 @@ 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 || COMPILE_TEST + 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 f08f8de..a145ad1 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -59,6 +59,7 @@ 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..22812e7 --- /dev/null +++ b/drivers/dma/stm32-dmamux.c @@ -0,0 +1,327 @@ +/* + * + * Copyright (C) STMicroelectronics SA 2017 + * Author(s): M'boumba Cedric Madianga + * Pierre-Yves Mordret + * + * License terms: GPL V2.0. + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * DMA Router driver for STM32 DMA MUX + * + * Based on TI DMA Crossbar driver + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define STM32_DMAMUX_CCR(x) (0x4 * (x)) +#define STM32_DMAMUX_MAX_DMA_REQUESTS 32 +#define STM32_DMAMUX_MAX_REQUESTS 255 + +struct stm32_dmamux { + u32 master; + u32 request; + u32 chan_id; +}; + +struct stm32_dmamux_data { + struct dma_router dmarouter; + struct clk *clk; + struct reset_control *rst; + void __iomem *iomem; + u32 dma_requests; /* Number of DMA requests connected to DMAMUX */ + u32 dmamux_requests; /* Number of DMA requests routed toward DMAs */ + spinlock_t lock; /* Protects register access */ + unsigned long *dma_inuse; /* Used DMA channel */ + u32 dma_reqs[]; /* Number of DMA Request per DMA masters. + * [0] holds number of DMA Masters. + * To be kept at very end end of this structure + */ +}; + +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; + unsigned long flags; + + /* Clear dma request */ + spin_lock_irqsave(&dmamux->lock, flags); + + stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), 0); + clear_bit(mux->chan_id, dmamux->dma_inuse); + + if (!IS_ERR(dmamux->clk)) + clk_disable(dmamux->clk); + + spin_unlock_irqrestore(&dmamux->lock, flags); + + dev_dbg(dev, "Unmapping DMAMUX(%u) to DMA%u(%u)\n", + mux->request, mux->master, mux->chan_id); + + kfree(mux); +} + +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 i, min, max; + int ret; + unsigned long flags; + + if (dma_spec->args_count != 3) { + dev_err(&pdev->dev, "invalid number of dma mux args\n"); + return ERR_PTR(-EINVAL); + } + + if (dma_spec->args[0] > dmamux->dmamux_requests) { + dev_err(&pdev->dev, "invalid mux request number: %d\n", + dma_spec->args[0]); + return ERR_PTR(-EINVAL); + } + + mux = kzalloc(sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + spin_lock_irqsave(&dmamux->lock, flags); + mux->chan_id = find_first_zero_bit(dmamux->dma_inuse, + dmamux->dma_requests); + set_bit(mux->chan_id, dmamux->dma_inuse); + spin_unlock_irqrestore(&dmamux->lock, flags); + + if (mux->chan_id == dmamux->dma_requests) { + dev_err(&pdev->dev, "Run out of free DMA requests\n"); + ret = -ENOMEM; + goto error; + } + + /* Look for DMA Master */ + for (i = 1, min = 0, max = dmamux->dma_reqs[i]; + i <= dmamux->dma_reqs[0]; + min += dmamux->dma_reqs[i], max += dmamux->dma_reqs[++i]) + if (mux->chan_id < max) + break; + mux->master = i - 1; + + /* The of_node_put() will be done in of_dma_router_xlate function */ + dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", i - 1); + if (!dma_spec->np) { + dev_err(&pdev->dev, "can't get dma master\n"); + ret = -EINVAL; + goto error; + } + + /* Set dma request */ + spin_lock_irqsave(&dmamux->lock, flags); + if (!IS_ERR(dmamux->clk)) { + ret = clk_enable(dmamux->clk); + if (ret < 0) { + spin_unlock_irqrestore(&dmamux->lock, flags); + dev_err(&pdev->dev, "clk_prep_enable issue: %d\n", ret); + goto error; + } + } + spin_unlock_irqrestore(&dmamux->lock, flags); + + mux->request = dma_spec->args[0]; + + /* craft DMA spec */ + dma_spec->args[3] = dma_spec->args[2]; + dma_spec->args[2] = dma_spec->args[1]; + dma_spec->args[1] = 0; + dma_spec->args[0] = mux->chan_id - min; + dma_spec->args_count = 4; + + stm32_dmamux_write(dmamux->iomem, STM32_DMAMUX_CCR(mux->chan_id), + mux->request); + dev_dbg(&pdev->dev, "Mapping DMAMUX(%u) to DMA%u(%u)\n", + mux->request, mux->master, mux->chan_id); + + return mux; + +error: + clear_bit(mux->chan_id, dmamux->dma_inuse); + kfree(mux); + return ERR_PTR(ret); +} + +static const struct of_device_id stm32_stm32dma_master_match[] = { + { .compatible = "st,stm32-dma", }, + {}, +}; + +static int stm32_dmamux_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + const struct of_device_id *match; + struct device_node *dma_node; + struct stm32_dmamux_data *stm32_dmamux; + struct resource *res; + void __iomem *iomem; + int i, count, ret; + u32 dma_req; + + if (!node) + return -ENODEV; + + count = device_property_read_u32_array(&pdev->dev, "dma-masters", + NULL, 0); + if (count < 0) { + dev_err(&pdev->dev, "Can't get DMA master(s) node\n"); + return -ENODEV; + } + + stm32_dmamux = devm_kzalloc(&pdev->dev, sizeof(*stm32_dmamux) + + sizeof(u32) * (count + 1), GFP_KERNEL); + if (!stm32_dmamux) + return -ENOMEM; + + dma_req = 0; + for (i = 1; i <= count; i++) { + dma_node = of_parse_phandle(node, "dma-masters", i - 1); + + match = of_match_node(stm32_stm32dma_master_match, dma_node); + if (!match) { + dev_err(&pdev->dev, "DMA master is not supported\n"); + of_node_put(dma_node); + return -EINVAL; + } + + if (of_property_read_u32(dma_node, "dma-requests", + &stm32_dmamux->dma_reqs[i])) { + dev_info(&pdev->dev, + "Missing MUX output information, using %u.\n", + STM32_DMAMUX_MAX_DMA_REQUESTS); + stm32_dmamux->dma_reqs[i] = + STM32_DMAMUX_MAX_DMA_REQUESTS; + } + dma_req += stm32_dmamux->dma_reqs[i]; + of_node_put(dma_node); + } + + if (dma_req > STM32_DMAMUX_MAX_DMA_REQUESTS) { + dev_err(&pdev->dev, "Too many DMA Master Requests to manage\n"); + return -ENODEV; + } + + stm32_dmamux->dma_requests = dma_req; + stm32_dmamux->dma_reqs[0] = count; + stm32_dmamux->dma_inuse = devm_kcalloc(&pdev->dev, + BITS_TO_LONGS(dma_req), + sizeof(unsigned long), + GFP_KERNEL); + if (!stm32_dmamux->dma_inuse) + return -ENOMEM; + + if (device_property_read_u32(&pdev->dev, "dma-requests", + &stm32_dmamux->dmamux_requests)) { + stm32_dmamux->dmamux_requests = STM32_DMAMUX_MAX_REQUESTS; + dev_warn(&pdev->dev, "DMAMUX defaulting on %u requests\n", + stm32_dmamux->dmamux_requests); + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + iomem = devm_ioremap_resource(&pdev->dev, res); + if (!iomem) + return -ENOMEM; + + spin_lock_init(&stm32_dmamux->lock); + + stm32_dmamux->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(stm32_dmamux->clk)) { + ret = PTR_ERR(stm32_dmamux->clk); + if (ret == -EPROBE_DEFER) + dev_info(&pdev->dev, "Missing controller clock\n"); + return ret; + } + + stm32_dmamux->rst = devm_reset_control_get(&pdev->dev, NULL); + if (!IS_ERR(stm32_dmamux->rst)) { + reset_control_assert(stm32_dmamux->rst); + udelay(2); + reset_control_deassert(stm32_dmamux->rst); + } + + stm32_dmamux->iomem = iomem; + stm32_dmamux->dmarouter.dev = &pdev->dev; + stm32_dmamux->dmarouter.route_free = stm32_dmamux_free; + + platform_set_drvdata(pdev, stm32_dmamux); + + if (!IS_ERR(stm32_dmamux->clk)) { + ret = clk_prepare_enable(stm32_dmamux->clk); + if (ret < 0) { + dev_err(&pdev->dev, "clk_prep_enable error: %d\n", ret); + return ret; + } + } + + /* Reset the dmamux */ + for (i = 0; i < stm32_dmamux->dma_requests; i++) + stm32_dmamux_write(stm32_dmamux->iomem, STM32_DMAMUX_CCR(i), 0); + + if (!IS_ERR(stm32_dmamux->clk)) + clk_disable(stm32_dmamux->clk); + + return of_dma_router_register(node, stm32_dmamux_route_allocate, + &stm32_dmamux->dmarouter); +} + +static const struct of_device_id stm32_dmamux_match[] = { + { .compatible = "st,stm32h7-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); + +MODULE_DESCRIPTION("DMA Router driver for STM32 DMA MUX"); +MODULE_AUTHOR("M'boumba Cedric Madianga "); +MODULE_AUTHOR("Pierre-Yves Mordret "); +MODULE_LICENSE("GPL v2");