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20e9969b DB |
1 | /* |
2 | * mach-davinci/sram.c - DaVinci simple SRAM allocator | |
3 | * | |
4 | * Copyright (C) 2009 David Brownell | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | */ | |
11 | #include <linux/module.h> | |
20e9969b | 12 | #include <linux/init.h> |
626863a3 | 13 | #include <linux/io.h> |
20e9969b DB |
14 | #include <linux/genalloc.h> |
15 | ||
16 | #include <mach/common.h> | |
20e9969b DB |
17 | #include <mach/sram.h> |
18 | ||
20e9969b DB |
19 | static struct gen_pool *sram_pool; |
20 | ||
983c42ba MP |
21 | struct gen_pool *sram_get_gen_pool(void) |
22 | { | |
23 | return sram_pool; | |
24 | } | |
25 | ||
20e9969b DB |
26 | void *sram_alloc(size_t len, dma_addr_t *dma) |
27 | { | |
28 | unsigned long vaddr; | |
29 | dma_addr_t dma_base = davinci_soc_info.sram_dma; | |
30 | ||
31 | if (dma) | |
32 | *dma = 0; | |
33 | if (!sram_pool || (dma && !dma_base)) | |
34 | return NULL; | |
35 | ||
36 | vaddr = gen_pool_alloc(sram_pool, len); | |
37 | if (!vaddr) | |
38 | return NULL; | |
39 | ||
40 | if (dma) | |
626863a3 | 41 | *dma = gen_pool_virt_to_phys(sram_pool, vaddr); |
20e9969b DB |
42 | return (void *)vaddr; |
43 | ||
44 | } | |
45 | EXPORT_SYMBOL(sram_alloc); | |
46 | ||
47 | void sram_free(void *addr, size_t len) | |
48 | { | |
49 | gen_pool_free(sram_pool, (unsigned long) addr, len); | |
50 | } | |
51 | EXPORT_SYMBOL(sram_free); | |
52 | ||
53 | ||
54 | /* | |
55 | * REVISIT This supports CPU and DMA access to/from SRAM, but it | |
56 | * doesn't (yet?) support some other notable uses of SRAM: as TCM | |
57 | * for data and/or instructions; and holding code needed to enter | |
58 | * and exit suspend states (while DRAM can't be used). | |
59 | */ | |
60 | static int __init sram_init(void) | |
61 | { | |
626863a3 | 62 | phys_addr_t phys = davinci_soc_info.sram_dma; |
20e9969b DB |
63 | unsigned len = davinci_soc_info.sram_len; |
64 | int status = 0; | |
626863a3 | 65 | void *addr; |
20e9969b DB |
66 | |
67 | if (len) { | |
1d3bba61 | 68 | len = min_t(unsigned, len, SRAM_SIZE); |
20e9969b DB |
69 | sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); |
70 | if (!sram_pool) | |
71 | status = -ENOMEM; | |
72 | } | |
626863a3 BG |
73 | |
74 | if (sram_pool) { | |
75 | addr = ioremap(phys, len); | |
76 | if (!addr) | |
77 | return -ENOMEM; | |
78 | status = gen_pool_add_virt(sram_pool, (unsigned)addr, | |
79 | phys, len, -1); | |
80 | if (status < 0) | |
81 | iounmap(addr); | |
82 | } | |
83 | ||
20e9969b DB |
84 | WARN_ON(status < 0); |
85 | return status; | |
86 | } | |
87 | core_initcall(sram_init); | |
88 |