summaryrefslogtreecommitdiff
path: root/drivers/dma/ti-dma-crossbar.c
blob: 24f5ca2356bfcaf3b370b7b8ddee4f0992a2ee57 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/*
 *  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);