dmaengine: Add driver for TI DMA crossbar on DRA7x (a074ae38) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/dma/Kconfig

+4 −0

Original line number	Diff line number	Diff line
		@@ -245,6 +245,9 @@ config TI_EDMA
		Enable support for the TI EDMA controller. This DMA
		engine is found on TI DaVinci and AM33xx parts.

		config TI_DMA_CROSSBAR
		bool

		config ARCH_HAS_ASYNC_TX_FIND_CHANNEL
		bool

		@@ -330,6 +333,7 @@ config DMA_OMAP
		depends on ARCH_OMAP
		select DMA_ENGINE
		select DMA_VIRTUAL_CHANNELS
		select TI_DMA_CROSSBAR if SOC_DRA7XX

		config DMA_BCM2835
		tristate "BCM2835 DMA engine support"

drivers/dma/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,7 @@ obj-$(CONFIG_EP93XX_DMA) += ep93xx_dma.o
		obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
		obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
		obj-$(CONFIG_DMA_OMAP) += omap-dma.o
		obj-$(CONFIG_TI_DMA_CROSSBAR) += ti-dma-crossbar.o
		obj-$(CONFIG_DMA_BCM2835) += bcm2835-dma.o
		obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
		obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o

drivers/dma/ti-dma-crossbar.c

0 → 100644

+188 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
		* Author: Peter Ujfalusi <peter.ujfalusi@ti.com>
		*
		* 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 <linux/slab.h>
		#include <linux/err.h>
		#include <linux/init.h>
		#include <linux/list.h>
		#include <linux/io.h>
		#include <linux/idr.h>
		#include <linux/of_address.h>
		#include <linux/of_device.h>
		#include <linux/of_dma.h>

		#define TI_XBAR_OUTPUTS 127
		#define TI_XBAR_INPUTS 256

		static DEFINE_IDR(map_idr);

		struct ti_dma_xbar_data {
		void __iomem *iomem;

		struct dma_router dmarouter;

		u16 safe_val; /* Value to rest the crossbar lines */
		u32 xbar_requests; /* number of DMA requests connected to XBAR */
		u32 dma_requests; /* number of DMA requests forwarded to DMA */
		};

		struct ti_dma_xbar_map {
		u16 xbar_in;
		int xbar_out;
		};

		static inline void ti_dma_xbar_write(void __iomem *iomem, int xbar, u16 val)
		{
		writew_relaxed(val, iomem + (xbar * 2));
		}

		static void ti_dma_xbar_free(struct device dev, void route_data)
		{
		struct ti_dma_xbar_data *xbar = dev_get_drvdata(dev);
		struct ti_dma_xbar_map *map = route_data;

		dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n",
		map->xbar_in, map->xbar_out);

		ti_dma_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
		idr_remove(&map_idr, map->xbar_out);
		kfree(map);
		}

		static void ti_dma_xbar_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 ti_dma_xbar_data *xbar = platform_get_drvdata(pdev);
		struct ti_dma_xbar_map *map;

		if (dma_spec->args[0] >= xbar->xbar_requests) {
		dev_err(&pdev->dev, "Invalid XBAR request number: %d\n",
		dma_spec->args[0]);
		return ERR_PTR(-EINVAL);
		}

		/* The of_node_put() will be done in the core for the node */
		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);
		}

		map = kzalloc(sizeof(*map), GFP_KERNEL);
		if (!map) {
		of_node_put(dma_spec->np);
		return ERR_PTR(-ENOMEM);
		}

		map->xbar_out = idr_alloc(&map_idr, NULL, 0, xbar->dma_requests,
		GFP_KERNEL);
		map->xbar_in = (u16)dma_spec->args[0];

		/* The DMA request is 1 based in sDMA */
		dma_spec->args[0] = map->xbar_out + 1;

		dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n",
		map->xbar_in, map->xbar_out);

		ti_dma_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);

		return map;
		}

		static int ti_dma_xbar_probe(struct platform_device *pdev)
		{
		struct device_node *node = pdev->dev.of_node;
		struct device_node *dma_node;
		struct ti_dma_xbar_data *xbar;
		struct resource *res;
		u32 safe_val;
		void __iomem *iomem;
		int i, ret;

		if (!node)
		return -ENODEV;

		xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL);
		if (!xbar)
		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;
		}

		if (of_property_read_u32(dma_node, "dma-requests",
		&xbar->dma_requests)) {
		dev_info(&pdev->dev,
		"Missing XBAR output information, using %u.\n",
		TI_XBAR_OUTPUTS);
		xbar->dma_requests = TI_XBAR_OUTPUTS;
		}
		of_node_put(dma_node);

		if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
		dev_info(&pdev->dev,
		"Missing XBAR input information, using %u.\n",
		TI_XBAR_INPUTS);
		xbar->xbar_requests = TI_XBAR_INPUTS;
		}

		if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val))
		xbar->safe_val = (u16)safe_val;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (!res)
		return -ENODEV;

		iomem = devm_ioremap_resource(&pdev->dev, res);
		if (!iomem)
		return -ENOMEM;

		xbar->iomem = iomem;

		xbar->dmarouter.dev = &pdev->dev;
		xbar->dmarouter.route_free = ti_dma_xbar_free;

		platform_set_drvdata(pdev, xbar);

		/* Reset the crossbar */
		for (i = 0; i < xbar->dma_requests; i++)
		ti_dma_xbar_write(xbar->iomem, i, xbar->safe_val);

		ret = of_dma_router_register(node, ti_dma_xbar_route_allocate,
		&xbar->dmarouter);
		if (ret) {
		/* Restore the defaults for the crossbar */
		for (i = 0; i < xbar->dma_requests; i++)
		ti_dma_xbar_write(xbar->iomem, i, i);
		}

		return ret;
		}

		static const struct of_device_id ti_dma_xbar_match[] = {
		{ .compatible = "ti,dra7-dma-crossbar" },
		{},
		};

		static struct platform_driver ti_dma_xbar_driver = {
		.driver = {
		.name = "ti-dma-crossbar",
		.of_match_table = of_match_ptr(ti_dma_xbar_match),
		},
		.probe = ti_dma_xbar_probe,
		};

		int omap_dmaxbar_init(void)
		{
		return platform_driver_register(&ti_dma_xbar_driver);
		}
		arch_initcall(omap_dmaxbar_init);