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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> | |
3acf731c | 17 | #include "sram.h" |
20e9969b | 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 | { | |
20e9969b DB |
28 | dma_addr_t dma_base = davinci_soc_info.sram_dma; |
29 | ||
30 | if (dma) | |
31 | *dma = 0; | |
32 | if (!sram_pool || (dma && !dma_base)) | |
33 | return NULL; | |
34 | ||
66f11969 | 35 | return gen_pool_dma_alloc(sram_pool, len, dma); |
20e9969b DB |
36 | |
37 | } | |
38 | EXPORT_SYMBOL(sram_alloc); | |
39 | ||
40 | void sram_free(void *addr, size_t len) | |
41 | { | |
42 | gen_pool_free(sram_pool, (unsigned long) addr, len); | |
43 | } | |
44 | EXPORT_SYMBOL(sram_free); | |
45 | ||
46 | ||
47 | /* | |
48 | * REVISIT This supports CPU and DMA access to/from SRAM, but it | |
49 | * doesn't (yet?) support some other notable uses of SRAM: as TCM | |
50 | * for data and/or instructions; and holding code needed to enter | |
51 | * and exit suspend states (while DRAM can't be used). | |
52 | */ | |
53 | static int __init sram_init(void) | |
54 | { | |
626863a3 | 55 | phys_addr_t phys = davinci_soc_info.sram_dma; |
20e9969b DB |
56 | unsigned len = davinci_soc_info.sram_len; |
57 | int status = 0; | |
182e7961 | 58 | void __iomem *addr; |
20e9969b DB |
59 | |
60 | if (len) { | |
1d3bba61 | 61 | len = min_t(unsigned, len, SRAM_SIZE); |
20e9969b DB |
62 | sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); |
63 | if (!sram_pool) | |
64 | status = -ENOMEM; | |
65 | } | |
626863a3 BG |
66 | |
67 | if (sram_pool) { | |
68 | addr = ioremap(phys, len); | |
69 | if (!addr) | |
70 | return -ENOMEM; | |
182e7961 | 71 | status = gen_pool_add_virt(sram_pool, (unsigned long) addr, |
626863a3 BG |
72 | phys, len, -1); |
73 | if (status < 0) | |
74 | iounmap(addr); | |
75 | } | |
76 | ||
20e9969b DB |
77 | WARN_ON(status < 0); |
78 | return status; | |
79 | } | |
80 | core_initcall(sram_init); | |
81 |