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a074ae38 PU |
1 | /* |
2 | * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com | |
3 | * Author: Peter Ujfalusi <peter.ujfalusi@ti.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | */ | |
10 | #include <linux/slab.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/list.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/idr.h> | |
16 | #include <linux/of_address.h> | |
17 | #include <linux/of_device.h> | |
18 | #include <linux/of_dma.h> | |
19 | ||
20 | #define TI_XBAR_OUTPUTS 127 | |
21 | #define TI_XBAR_INPUTS 256 | |
22 | ||
23 | static DEFINE_IDR(map_idr); | |
24 | ||
25 | struct ti_dma_xbar_data { | |
26 | void __iomem *iomem; | |
27 | ||
28 | struct dma_router dmarouter; | |
29 | ||
30 | u16 safe_val; /* Value to rest the crossbar lines */ | |
31 | u32 xbar_requests; /* number of DMA requests connected to XBAR */ | |
32 | u32 dma_requests; /* number of DMA requests forwarded to DMA */ | |
33 | }; | |
34 | ||
35 | struct ti_dma_xbar_map { | |
36 | u16 xbar_in; | |
37 | int xbar_out; | |
38 | }; | |
39 | ||
40 | static inline void ti_dma_xbar_write(void __iomem *iomem, int xbar, u16 val) | |
41 | { | |
42 | writew_relaxed(val, iomem + (xbar * 2)); | |
43 | } | |
44 | ||
45 | static void ti_dma_xbar_free(struct device *dev, void *route_data) | |
46 | { | |
47 | struct ti_dma_xbar_data *xbar = dev_get_drvdata(dev); | |
48 | struct ti_dma_xbar_map *map = route_data; | |
49 | ||
50 | dev_dbg(dev, "Unmapping XBAR%u (was routed to %d)\n", | |
51 | map->xbar_in, map->xbar_out); | |
52 | ||
53 | ti_dma_xbar_write(xbar->iomem, map->xbar_out, xbar->safe_val); | |
54 | idr_remove(&map_idr, map->xbar_out); | |
55 | kfree(map); | |
56 | } | |
57 | ||
58 | static void *ti_dma_xbar_route_allocate(struct of_phandle_args *dma_spec, | |
59 | struct of_dma *ofdma) | |
60 | { | |
61 | struct platform_device *pdev = of_find_device_by_node(ofdma->of_node); | |
62 | struct ti_dma_xbar_data *xbar = platform_get_drvdata(pdev); | |
63 | struct ti_dma_xbar_map *map; | |
64 | ||
65 | if (dma_spec->args[0] >= xbar->xbar_requests) { | |
66 | dev_err(&pdev->dev, "Invalid XBAR request number: %d\n", | |
67 | dma_spec->args[0]); | |
68 | return ERR_PTR(-EINVAL); | |
69 | } | |
70 | ||
71 | /* The of_node_put() will be done in the core for the node */ | |
72 | dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0); | |
73 | if (!dma_spec->np) { | |
74 | dev_err(&pdev->dev, "Can't get DMA master\n"); | |
75 | return ERR_PTR(-EINVAL); | |
76 | } | |
77 | ||
78 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
79 | if (!map) { | |
80 | of_node_put(dma_spec->np); | |
81 | return ERR_PTR(-ENOMEM); | |
82 | } | |
83 | ||
84 | map->xbar_out = idr_alloc(&map_idr, NULL, 0, xbar->dma_requests, | |
85 | GFP_KERNEL); | |
86 | map->xbar_in = (u16)dma_spec->args[0]; | |
87 | ||
88 | /* The DMA request is 1 based in sDMA */ | |
89 | dma_spec->args[0] = map->xbar_out + 1; | |
90 | ||
91 | dev_dbg(&pdev->dev, "Mapping XBAR%u to DMA%d\n", | |
92 | map->xbar_in, map->xbar_out); | |
93 | ||
94 | ti_dma_xbar_write(xbar->iomem, map->xbar_out, map->xbar_in); | |
95 | ||
96 | return map; | |
97 | } | |
98 | ||
99 | static int ti_dma_xbar_probe(struct platform_device *pdev) | |
100 | { | |
101 | struct device_node *node = pdev->dev.of_node; | |
102 | struct device_node *dma_node; | |
103 | struct ti_dma_xbar_data *xbar; | |
104 | struct resource *res; | |
105 | u32 safe_val; | |
106 | void __iomem *iomem; | |
107 | int i, ret; | |
108 | ||
109 | if (!node) | |
110 | return -ENODEV; | |
111 | ||
112 | xbar = devm_kzalloc(&pdev->dev, sizeof(*xbar), GFP_KERNEL); | |
113 | if (!xbar) | |
114 | return -ENOMEM; | |
115 | ||
116 | dma_node = of_parse_phandle(node, "dma-masters", 0); | |
117 | if (!dma_node) { | |
118 | dev_err(&pdev->dev, "Can't get DMA master node\n"); | |
119 | return -ENODEV; | |
120 | } | |
121 | ||
122 | if (of_property_read_u32(dma_node, "dma-requests", | |
123 | &xbar->dma_requests)) { | |
124 | dev_info(&pdev->dev, | |
125 | "Missing XBAR output information, using %u.\n", | |
126 | TI_XBAR_OUTPUTS); | |
127 | xbar->dma_requests = TI_XBAR_OUTPUTS; | |
128 | } | |
129 | of_node_put(dma_node); | |
130 | ||
131 | if (of_property_read_u32(node, "dma-requests", &xbar->xbar_requests)) { | |
132 | dev_info(&pdev->dev, | |
133 | "Missing XBAR input information, using %u.\n", | |
134 | TI_XBAR_INPUTS); | |
135 | xbar->xbar_requests = TI_XBAR_INPUTS; | |
136 | } | |
137 | ||
138 | if (!of_property_read_u32(node, "ti,dma-safe-map", &safe_val)) | |
139 | xbar->safe_val = (u16)safe_val; | |
140 | ||
141 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
142 | if (!res) | |
143 | return -ENODEV; | |
144 | ||
145 | iomem = devm_ioremap_resource(&pdev->dev, res); | |
146 | if (!iomem) | |
147 | return -ENOMEM; | |
148 | ||
149 | xbar->iomem = iomem; | |
150 | ||
151 | xbar->dmarouter.dev = &pdev->dev; | |
152 | xbar->dmarouter.route_free = ti_dma_xbar_free; | |
153 | ||
154 | platform_set_drvdata(pdev, xbar); | |
155 | ||
156 | /* Reset the crossbar */ | |
157 | for (i = 0; i < xbar->dma_requests; i++) | |
158 | ti_dma_xbar_write(xbar->iomem, i, xbar->safe_val); | |
159 | ||
160 | ret = of_dma_router_register(node, ti_dma_xbar_route_allocate, | |
161 | &xbar->dmarouter); | |
162 | if (ret) { | |
163 | /* Restore the defaults for the crossbar */ | |
164 | for (i = 0; i < xbar->dma_requests; i++) | |
165 | ti_dma_xbar_write(xbar->iomem, i, i); | |
166 | } | |
167 | ||
168 | return ret; | |
169 | } | |
170 | ||
171 | static const struct of_device_id ti_dma_xbar_match[] = { | |
172 | { .compatible = "ti,dra7-dma-crossbar" }, | |
173 | {}, | |
174 | }; | |
175 | ||
176 | static struct platform_driver ti_dma_xbar_driver = { | |
177 | .driver = { | |
178 | .name = "ti-dma-crossbar", | |
179 | .of_match_table = of_match_ptr(ti_dma_xbar_match), | |
180 | }, | |
181 | .probe = ti_dma_xbar_probe, | |
182 | }; | |
183 | ||
184 | int omap_dmaxbar_init(void) | |
185 | { | |
186 | return platform_driver_register(&ti_dma_xbar_driver); | |
187 | } | |
188 | arch_initcall(omap_dmaxbar_init); |