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d666cd02 KC |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 2014 Kevin Cernekee <cernekee@gmail.com> | |
7 | */ | |
8 | ||
1ada656f KC |
9 | #define pr_fmt(fmt) "bmips-dma: " fmt |
10 | ||
d666cd02 KC |
11 | #include <linux/device.h> |
12 | #include <linux/dma-direction.h> | |
13 | #include <linux/dma-mapping.h> | |
14 | #include <linux/init.h> | |
1ada656f | 15 | #include <linux/io.h> |
d666cd02 | 16 | #include <linux/of.h> |
1ada656f KC |
17 | #include <linux/printk.h> |
18 | #include <linux/slab.h> | |
d666cd02 KC |
19 | #include <linux/types.h> |
20 | #include <dma-coherence.h> | |
21 | ||
22 | /* | |
1ada656f | 23 | * BCM338x has configurable address translation windows which allow the |
d666cd02 KC |
24 | * peripherals' DMA addresses to be different from the Zephyr-visible |
25 | * physical addresses. e.g. usb_dma_addr = zephyr_pa ^ 0x08000000 | |
26 | * | |
1ada656f KC |
27 | * If the "brcm,ubus" node has a "dma-ranges" property we will enable this |
28 | * translation globally using the provided information. This implements a | |
29 | * very limited subset of "dma-ranges" support and it will probably be | |
30 | * replaced by a more generic version later. | |
d666cd02 | 31 | */ |
d666cd02 | 32 | |
1ada656f KC |
33 | struct bmips_dma_range { |
34 | u32 child_addr; | |
35 | u32 parent_addr; | |
36 | u32 size; | |
37 | }; | |
d666cd02 | 38 | |
1ada656f KC |
39 | static struct bmips_dma_range *bmips_dma_ranges; |
40 | ||
41 | #define FLUSH_RAC 0x100 | |
42 | ||
43 | static dma_addr_t bmips_phys_to_dma(struct device *dev, phys_addr_t pa) | |
d666cd02 | 44 | { |
1ada656f KC |
45 | struct bmips_dma_range *r; |
46 | ||
47 | for (r = bmips_dma_ranges; r && r->size; r++) { | |
48 | if (pa >= r->child_addr && | |
49 | pa < (r->child_addr + r->size)) | |
50 | return pa - r->child_addr + r->parent_addr; | |
51 | } | |
d666cd02 KC |
52 | return pa; |
53 | } | |
54 | ||
55 | dma_addr_t plat_map_dma_mem(struct device *dev, void *addr, size_t size) | |
56 | { | |
1ada656f | 57 | return bmips_phys_to_dma(dev, virt_to_phys(addr)); |
d666cd02 KC |
58 | } |
59 | ||
60 | dma_addr_t plat_map_dma_mem_page(struct device *dev, struct page *page) | |
61 | { | |
1ada656f | 62 | return bmips_phys_to_dma(dev, page_to_phys(page)); |
d666cd02 KC |
63 | } |
64 | ||
65 | unsigned long plat_dma_addr_to_phys(struct device *dev, dma_addr_t dma_addr) | |
66 | { | |
1ada656f KC |
67 | struct bmips_dma_range *r; |
68 | ||
69 | for (r = bmips_dma_ranges; r && r->size; r++) { | |
70 | if (dma_addr >= r->parent_addr && | |
71 | dma_addr < (r->parent_addr + r->size)) | |
72 | return dma_addr - r->parent_addr + r->child_addr; | |
73 | } | |
d666cd02 KC |
74 | return dma_addr; |
75 | } | |
76 | ||
1ada656f | 77 | static int __init bmips_init_dma_ranges(void) |
d666cd02 | 78 | { |
1ada656f KC |
79 | struct device_node *np = |
80 | of_find_compatible_node(NULL, NULL, "brcm,ubus"); | |
81 | const __be32 *data; | |
82 | struct bmips_dma_range *r; | |
83 | int len; | |
d666cd02 KC |
84 | |
85 | if (!np) | |
86 | return 0; | |
87 | ||
1ada656f KC |
88 | data = of_get_property(np, "dma-ranges", &len); |
89 | if (!data) | |
90 | goto out_good; | |
91 | ||
92 | len /= sizeof(*data) * 3; | |
93 | if (!len) | |
94 | goto out_bad; | |
95 | ||
96 | /* add a dummy (zero) entry at the end as a sentinel */ | |
97 | bmips_dma_ranges = kzalloc(sizeof(struct bmips_dma_range) * (len + 1), | |
98 | GFP_KERNEL); | |
99 | if (!bmips_dma_ranges) | |
100 | goto out_bad; | |
d666cd02 | 101 | |
1ada656f KC |
102 | for (r = bmips_dma_ranges; len; len--, r++) { |
103 | r->child_addr = be32_to_cpup(data++); | |
104 | r->parent_addr = be32_to_cpup(data++); | |
105 | r->size = be32_to_cpup(data++); | |
106 | } | |
107 | ||
108 | out_good: | |
d666cd02 KC |
109 | of_node_put(np); |
110 | return 0; | |
1ada656f KC |
111 | |
112 | out_bad: | |
113 | pr_err("error parsing dma-ranges property\n"); | |
114 | of_node_put(np); | |
115 | return -EINVAL; | |
d666cd02 | 116 | } |
1ada656f | 117 | arch_initcall(bmips_init_dma_ranges); |