drivers/dma/ti-dma-crossbar.c - kernel/msm-4.9 - Gitiles

 /*
  *  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/of_address.h>
 #include <linux/of_device.h>
 #include <linux/of_dma.h>

 #define TI_XBAR_DRA7		0
 #define TI_XBAR_AM335X		1
 static const u32 ti_xbar_type[] = {
 	[TI_XBAR_DRA7] = TI_XBAR_DRA7,
 	[TI_XBAR_AM335X] = TI_XBAR_AM335X,
 };

 static const struct of_device_id ti_dma_xbar_match[] = {
 	{
 		.compatible = "ti,dra7-dma-crossbar",
 		.data = &ti_xbar_type[TI_XBAR_DRA7],
 	},
 	{
 		.compatible = "ti,am335x-edma-crossbar",
 		.data = &ti_xbar_type[TI_XBAR_AM335X],
 	},
 	{},
 };

 /* Crossbar on AM335x/AM437x family */
 #define TI_AM335X_XBAR_LINES	64

 struct ti_am335x_xbar_data {
 	void __iomem *iomem;

 	struct dma_router dmarouter;

 	u32 xbar_events; /* maximum number of events to select in xbar */
 	u32 dma_requests; /* number of DMA requests on eDMA */
 };

 struct ti_am335x_xbar_map {
 	u16 dma_line;
 	u8 mux_val;
 };

 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
 {
 	writeb_relaxed(val, iomem + event);
 }

 static void ti_am335x_xbar_free(struct device *dev, void *route_data)
 {
 	struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
 	struct ti_am335x_xbar_map *map = route_data;

 	dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
 		map->mux_val, map->dma_line);

 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
 	kfree(map);
 }

 static void *ti_am335x_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_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
 	struct ti_am335x_xbar_map *map;

 	if (dma_spec->args_count != 3)
 		return ERR_PTR(-EINVAL);

 	if (dma_spec->args[2] >= xbar->xbar_events) {
 		dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
 			dma_spec->args[2]);
 		return ERR_PTR(-EINVAL);
 	}

 	if (dma_spec->args[0] >= xbar->dma_requests) {
 		dev_err(&pdev->dev, "Invalid DMA request line 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->dma_line = (u16)dma_spec->args[0];
 	map->mux_val = (u8)dma_spec->args[2];

 	dma_spec->args[2] = 0;
 	dma_spec->args_count = 2;

 	dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
 		map->mux_val, map->dma_line);

 	ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);

 	return map;
 }

 static const struct of_device_id ti_am335x_master_match[] = {
 	{ .compatible = "ti,edma3-tpcc", },
 	{},
 };

 static int ti_am335x_xbar_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 ti_am335x_xbar_data *xbar;
 	struct resource *res;
 	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;
 	}

 	match = of_match_node(ti_am335x_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",
 				 &xbar->dma_requests)) {
 		dev_info(&pdev->dev,
 			 "Missing XBAR output information, using %u.\n",
 			 TI_AM335X_XBAR_LINES);
 		xbar->dma_requests = TI_AM335X_XBAR_LINES;
 	}
 	of_node_put(dma_node);

 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
 		dev_info(&pdev->dev,
 			 "Missing XBAR input information, using %u.\n",
 			 TI_AM335X_XBAR_LINES);
 		xbar->xbar_events = TI_AM335X_XBAR_LINES;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	iomem = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(iomem))
 		return PTR_ERR(iomem);

 	xbar->iomem = iomem;

 	xbar->dmarouter.dev = &pdev->dev;
 	xbar->dmarouter.route_free = ti_am335x_xbar_free;

 	platform_set_drvdata(pdev, xbar);

 	/* Reset the crossbar */
 	for (i = 0; i < xbar->dma_requests; i++)
 		ti_am335x_xbar_write(xbar->iomem, i, 0);

 	ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
 				     &xbar->dmarouter);

 	return ret;
 }

 /* Crossbar on DRA7xx family */
 #define TI_DRA7_XBAR_OUTPUTS	127
 #define TI_DRA7_XBAR_INPUTS	256

 struct ti_dra7_xbar_data {
 	void __iomem *iomem;

 	struct dma_router dmarouter;
 	struct mutex mutex;
 	unsigned long *dma_inuse;

 	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 */
 	u32 dma_offset;
 };

 struct ti_dra7_xbar_map {
 	u16 xbar_in;
 	int xbar_out;
 };

 static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
 {
 	writew_relaxed(val, iomem + (xbar * 2));
 }

 static void ti_dra7_xbar_free(struct device *dev, void *route_data)
 {
 	struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
 	struct ti_dra7_xbar_map *map = route_data;

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

 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
 	mutex_lock(&xbar->mutex);
 	clear_bit(map->xbar_out, xbar->dma_inuse);
 	mutex_unlock(&xbar->mutex);
 	kfree(map);
 }

 static void *ti_dra7_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_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
 	struct ti_dra7_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);
 	}

 	mutex_lock(&xbar->mutex);
 	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
 					    xbar->dma_requests);
 	if (map->xbar_out == xbar->dma_requests) {
 		mutex_unlock(&xbar->mutex);
 		dev_err(&pdev->dev, "Run out of free DMA requests\n");
 		kfree(map);
 		return ERR_PTR(-ENOMEM);
 	}
 	set_bit(map->xbar_out, xbar->dma_inuse);
 	mutex_unlock(&xbar->mutex);

 	map->xbar_in = (u16)dma_spec->args[0];

 	dma_spec->args[0] = map->xbar_out + xbar->dma_offset;

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

 	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);

 	return map;
 }

 #define TI_XBAR_EDMA_OFFSET	0
 #define TI_XBAR_SDMA_OFFSET	1
 static const u32 ti_dma_offset[] = {
 	[TI_XBAR_EDMA_OFFSET] = 0,
 	[TI_XBAR_SDMA_OFFSET] = 1,
 };

 static const struct of_device_id ti_dra7_master_match[] = {
 	{
 		.compatible = "ti,omap4430-sdma",
 		.data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
 	},
 	{
 		.compatible = "ti,edma3",
 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 	},
 	{
 		.compatible = "ti,edma3-tpcc",
 		.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
 	},
 	{},
 };

 static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
 {
 	for (; len > 0; len--)
 		clear_bit(offset + (len - 1), p);
 }

 static int ti_dra7_xbar_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 ti_dra7_xbar_data *xbar;
 	struct property *prop;
 	struct resource *res;
 	u32 safe_val;
 	int sz;
 	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;
 	}

 	match = of_match_node(ti_dra7_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",
 				 &xbar->dma_requests)) {
 		dev_info(&pdev->dev,
 			 "Missing XBAR output information, using %u.\n",
 			 TI_DRA7_XBAR_OUTPUTS);
 		xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
 	}
 	of_node_put(dma_node);

 	xbar->dma_inuse = devm_kcalloc(&pdev->dev,
 				       BITS_TO_LONGS(xbar->dma_requests),
 				       sizeof(unsigned long), GFP_KERNEL);
 	if (!xbar->dma_inuse)
 		return -ENOMEM;

 	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
 		dev_info(&pdev->dev,
 			 "Missing XBAR input information, using %u.\n",
 			 TI_DRA7_XBAR_INPUTS);
 		xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
 	}

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


 	prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
 	if (prop) {
 		const char pname[] = "ti,reserved-dma-request-ranges";
 		u32 (*rsv_events)[2];
 		size_t nelm = sz / sizeof(*rsv_events);
 		int i;

 		if (!nelm)
 			return -EINVAL;

 		rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
 		if (!rsv_events)
 			return -ENOMEM;

 		ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
 						 nelm * 2);
 		if (ret)
 			return ret;

 		for (i = 0; i < nelm; i++) {
 			ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
 					     xbar->dma_inuse);
 		}
 		kfree(rsv_events);
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	iomem = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(iomem))
 		return PTR_ERR(iomem);

 	xbar->iomem = iomem;

 	xbar->dmarouter.dev = &pdev->dev;
 	xbar->dmarouter.route_free = ti_dra7_xbar_free;
 	xbar->dma_offset = *(u32 *)match->data;

 	mutex_init(&xbar->mutex);
 	platform_set_drvdata(pdev, xbar);

 	/* Reset the crossbar */
 	for (i = 0; i < xbar->dma_requests; i++) {
 		if (!test_bit(i, xbar->dma_inuse))
 			ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
 	}

 	ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
 				     &xbar->dmarouter);
 	if (ret) {
 		/* Restore the defaults for the crossbar */
 		for (i = 0; i < xbar->dma_requests; i++) {
 			if (!test_bit(i, xbar->dma_inuse))
 				ti_dra7_xbar_write(xbar->iomem, i, i);
 		}
 	}

 	return ret;
 }

 static int ti_dma_xbar_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
 	int ret;

 	match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
 	if (unlikely(!match))
 		return -EINVAL;

 	switch (*(u32 *)match->data) {
 	case TI_XBAR_DRA7:
 		ret = ti_dra7_xbar_probe(pdev);
 		break;
 	case TI_XBAR_AM335X:
 		ret = ti_am335x_xbar_probe(pdev);
 		break;
 	default:
 		dev_err(&pdev->dev, "Unsupported crossbar\n");
 		ret = -ENODEV;
 		break;
 	}

 	return ret;
 }

 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,
 };

 static int omap_dmaxbar_init(void)
 {
 	return platform_driver_register(&ti_dma_xbar_driver);
 }
 arch_initcall(omap_dmaxbar_init);
	/*
	* 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/of_address.h>
	#include <linux/of_device.h>
	#include <linux/of_dma.h>

	#define TI_XBAR_DRA7 0
	#define TI_XBAR_AM335X 1
	static const u32 ti_xbar_type[] = {
	[TI_XBAR_DRA7] = TI_XBAR_DRA7,
	[TI_XBAR_AM335X] = TI_XBAR_AM335X,
	};

	static const struct of_device_id ti_dma_xbar_match[] = {
	{
	.compatible = "ti,dra7-dma-crossbar",
	.data = &ti_xbar_type[TI_XBAR_DRA7],
	},
	{
	.compatible = "ti,am335x-edma-crossbar",
	.data = &ti_xbar_type[TI_XBAR_AM335X],
	},
	{},
	};

	/* Crossbar on AM335x/AM437x family */
	#define TI_AM335X_XBAR_LINES 64

	struct ti_am335x_xbar_data {
	void __iomem *iomem;

	struct dma_router dmarouter;

	u32 xbar_events; /* maximum number of events to select in xbar */
	u32 dma_requests; /* number of DMA requests on eDMA */
	};

	struct ti_am335x_xbar_map {
	u16 dma_line;
	u8 mux_val;
	};

	static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
	{
	writeb_relaxed(val, iomem + event);
	}

	static void ti_am335x_xbar_free(struct device dev, void route_data)
	{
	struct ti_am335x_xbar_data *xbar = dev_get_drvdata(dev);
	struct ti_am335x_xbar_map *map = route_data;

	dev_dbg(dev, "Unmapping XBAR event %u on channel %u\n",
	map->mux_val, map->dma_line);

	ti_am335x_xbar_write(xbar->iomem, map->dma_line, 0);
	kfree(map);
	}

	static void ti_am335x_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_am335x_xbar_data *xbar = platform_get_drvdata(pdev);
	struct ti_am335x_xbar_map *map;

	if (dma_spec->args_count != 3)
	return ERR_PTR(-EINVAL);

	if (dma_spec->args[2] >= xbar->xbar_events) {
	dev_err(&pdev->dev, "Invalid XBAR event number: %d\n",
	dma_spec->args[2]);
	return ERR_PTR(-EINVAL);
	}

	if (dma_spec->args[0] >= xbar->dma_requests) {
	dev_err(&pdev->dev, "Invalid DMA request line 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->dma_line = (u16)dma_spec->args[0];
	map->mux_val = (u8)dma_spec->args[2];

	dma_spec->args[2] = 0;
	dma_spec->args_count = 2;

	dev_dbg(&pdev->dev, "Mapping XBAR event%u to DMA%u\n",
	map->mux_val, map->dma_line);

	ti_am335x_xbar_write(xbar->iomem, map->dma_line, map->mux_val);

	return map;
	}

	static const struct of_device_id ti_am335x_master_match[] = {
	{ .compatible = "ti,edma3-tpcc", },
	{},
	};

	static int ti_am335x_xbar_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 ti_am335x_xbar_data *xbar;
	struct resource *res;
	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;
	}

	match = of_match_node(ti_am335x_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",
	&xbar->dma_requests)) {
	dev_info(&pdev->dev,
	"Missing XBAR output information, using %u.\n",
	TI_AM335X_XBAR_LINES);
	xbar->dma_requests = TI_AM335X_XBAR_LINES;
	}
	of_node_put(dma_node);

	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_events)) {
	dev_info(&pdev->dev,
	"Missing XBAR input information, using %u.\n",
	TI_AM335X_XBAR_LINES);
	xbar->xbar_events = TI_AM335X_XBAR_LINES;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	iomem = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(iomem))
	return PTR_ERR(iomem);

	xbar->iomem = iomem;

	xbar->dmarouter.dev = &pdev->dev;
	xbar->dmarouter.route_free = ti_am335x_xbar_free;

	platform_set_drvdata(pdev, xbar);

	/* Reset the crossbar */
	for (i = 0; i < xbar->dma_requests; i++)
	ti_am335x_xbar_write(xbar->iomem, i, 0);

	ret = of_dma_router_register(node, ti_am335x_xbar_route_allocate,
	&xbar->dmarouter);

	return ret;
	}

	/* Crossbar on DRA7xx family */
	#define TI_DRA7_XBAR_OUTPUTS 127
	#define TI_DRA7_XBAR_INPUTS 256

	struct ti_dra7_xbar_data {
	void __iomem *iomem;

	struct dma_router dmarouter;
	struct mutex mutex;
	unsigned long *dma_inuse;

	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 */
	u32 dma_offset;
	};

	struct ti_dra7_xbar_map {
	u16 xbar_in;
	int xbar_out;
	};

	static inline void ti_dra7_xbar_write(void __iomem *iomem, int xbar, u16 val)
	{
	writew_relaxed(val, iomem + (xbar * 2));
	}

	static void ti_dra7_xbar_free(struct device dev, void route_data)
	{
	struct ti_dra7_xbar_data *xbar = dev_get_drvdata(dev);
	struct ti_dra7_xbar_map *map = route_data;

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

	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val);
	mutex_lock(&xbar->mutex);
	clear_bit(map->xbar_out, xbar->dma_inuse);
	mutex_unlock(&xbar->mutex);
	kfree(map);
	}

	static void ti_dra7_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_dra7_xbar_data *xbar = platform_get_drvdata(pdev);
	struct ti_dra7_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);
	}

	mutex_lock(&xbar->mutex);
	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,
	xbar->dma_requests);
	if (map->xbar_out == xbar->dma_requests) {
	mutex_unlock(&xbar->mutex);
	dev_err(&pdev->dev, "Run out of free DMA requests\n");
	kfree(map);
	return ERR_PTR(-ENOMEM);
	}
	set_bit(map->xbar_out, xbar->dma_inuse);
	mutex_unlock(&xbar->mutex);

	map->xbar_in = (u16)dma_spec->args[0];

	dma_spec->args[0] = map->xbar_out + xbar->dma_offset;

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

	ti_dra7_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in);

	return map;
	}

	#define TI_XBAR_EDMA_OFFSET 0
	#define TI_XBAR_SDMA_OFFSET 1
	static const u32 ti_dma_offset[] = {
	[TI_XBAR_EDMA_OFFSET] = 0,
	[TI_XBAR_SDMA_OFFSET] = 1,
	};

	static const struct of_device_id ti_dra7_master_match[] = {
	{
	.compatible = "ti,omap4430-sdma",
	.data = &ti_dma_offset[TI_XBAR_SDMA_OFFSET],
	},
	{
	.compatible = "ti,edma3",
	.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
	},
	{
	.compatible = "ti,edma3-tpcc",
	.data = &ti_dma_offset[TI_XBAR_EDMA_OFFSET],
	},
	{},
	};

	static inline void ti_dra7_xbar_reserve(int offset, int len, unsigned long *p)
	{
	for (; len > 0; len--)
	clear_bit(offset + (len - 1), p);
	}

	static int ti_dra7_xbar_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 ti_dra7_xbar_data *xbar;
	struct property *prop;
	struct resource *res;
	u32 safe_val;
	int sz;
	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;
	}

	match = of_match_node(ti_dra7_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",
	&xbar->dma_requests)) {
	dev_info(&pdev->dev,
	"Missing XBAR output information, using %u.\n",
	TI_DRA7_XBAR_OUTPUTS);
	xbar->dma_requests = TI_DRA7_XBAR_OUTPUTS;
	}
	of_node_put(dma_node);

	xbar->dma_inuse = devm_kcalloc(&pdev->dev,
	BITS_TO_LONGS(xbar->dma_requests),
	sizeof(unsigned long), GFP_KERNEL);
	if (!xbar->dma_inuse)
	return -ENOMEM;

	if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) {
	dev_info(&pdev->dev,
	"Missing XBAR input information, using %u.\n",
	TI_DRA7_XBAR_INPUTS);
	xbar->xbar_requests = TI_DRA7_XBAR_INPUTS;
	}

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


	prop = of_find_property(node, "ti,reserved-dma-request-ranges", &sz);
	if (prop) {
	const char pname[] = "ti,reserved-dma-request-ranges";
	u32 (*rsv_events)[2];
	size_t nelm = sz / sizeof(*rsv_events);
	int i;

	if (!nelm)
	return -EINVAL;

	rsv_events = kcalloc(nelm, sizeof(*rsv_events), GFP_KERNEL);
	if (!rsv_events)
	return -ENOMEM;

	ret = of_property_read_u32_array(node, pname, (u32 *)rsv_events,
	nelm * 2);
	if (ret)
	return ret;

	for (i = 0; i < nelm; i++) {
	ti_dra7_xbar_reserve(rsv_events[i][0], rsv_events[i][1],
	xbar->dma_inuse);
	}
	kfree(rsv_events);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	iomem = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(iomem))
	return PTR_ERR(iomem);

	xbar->iomem = iomem;

	xbar->dmarouter.dev = &pdev->dev;
	xbar->dmarouter.route_free = ti_dra7_xbar_free;
	xbar->dma_offset = (u32 )match->data;

	mutex_init(&xbar->mutex);
	platform_set_drvdata(pdev, xbar);

	/* Reset the crossbar */
	for (i = 0; i < xbar->dma_requests; i++) {
	if (!test_bit(i, xbar->dma_inuse))
	ti_dra7_xbar_write(xbar->iomem, i, xbar->safe_val);
	}

	ret = of_dma_router_register(node, ti_dra7_xbar_route_allocate,
	&xbar->dmarouter);
	if (ret) {
	/* Restore the defaults for the crossbar */
	for (i = 0; i < xbar->dma_requests; i++) {
	if (!test_bit(i, xbar->dma_inuse))
	ti_dra7_xbar_write(xbar->iomem, i, i);
	}
	}

	return ret;
	}

	static int ti_dma_xbar_probe(struct platform_device *pdev)
	{
	const struct of_device_id *match;
	int ret;

	match = of_match_node(ti_dma_xbar_match, pdev->dev.of_node);
	if (unlikely(!match))
	return -EINVAL;

	switch ((u32 )match->data) {
	case TI_XBAR_DRA7:
	ret = ti_dra7_xbar_probe(pdev);
	break;
	case TI_XBAR_AM335X:
	ret = ti_am335x_xbar_probe(pdev);
	break;
	default:
	dev_err(&pdev->dev, "Unsupported crossbar\n");
	ret = -ENODEV;
	break;
	}

	return ret;
	}

	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,
	};

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