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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-05-29 05:04:24 -0400 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-05-29 05:04:24 -0400 |
commit | 42f1d2e06a25628ae4ceaadccc4fa67c7787e2b4 (patch) | |
tree | 8aac83e399de7ad13748a59853a0feea9ed2c5cb /arch/arm/mach-davinci/sram.c | |
parent | 9af5324a070e0b2dcb6e22c89e17424eba245fcc (diff) | |
parent | 77bbca138c64cb80259732db6f70e1668123f2a7 (diff) |
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci into devel
Diffstat (limited to 'arch/arm/mach-davinci/sram.c')
-rw-r--r-- | arch/arm/mach-davinci/sram.c | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/sram.c b/arch/arm/mach-davinci/sram.c new file mode 100644 index 000000000000..db54b2a66b4d --- /dev/null +++ b/arch/arm/mach-davinci/sram.c | |||
@@ -0,0 +1,74 @@ | |||
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> | ||
12 | #include <linux/kernel.h> | ||
13 | #include <linux/init.h> | ||
14 | #include <linux/genalloc.h> | ||
15 | |||
16 | #include <mach/common.h> | ||
17 | #include <mach/memory.h> | ||
18 | #include <mach/sram.h> | ||
19 | |||
20 | |||
21 | static struct gen_pool *sram_pool; | ||
22 | |||
23 | void *sram_alloc(size_t len, dma_addr_t *dma) | ||
24 | { | ||
25 | unsigned long vaddr; | ||
26 | dma_addr_t dma_base = davinci_soc_info.sram_dma; | ||
27 | |||
28 | if (dma) | ||
29 | *dma = 0; | ||
30 | if (!sram_pool || (dma && !dma_base)) | ||
31 | return NULL; | ||
32 | |||
33 | vaddr = gen_pool_alloc(sram_pool, len); | ||
34 | if (!vaddr) | ||
35 | return NULL; | ||
36 | |||
37 | if (dma) | ||
38 | *dma = dma_base + (vaddr - SRAM_VIRT); | ||
39 | return (void *)vaddr; | ||
40 | |||
41 | } | ||
42 | EXPORT_SYMBOL(sram_alloc); | ||
43 | |||
44 | void sram_free(void *addr, size_t len) | ||
45 | { | ||
46 | gen_pool_free(sram_pool, (unsigned long) addr, len); | ||
47 | } | ||
48 | EXPORT_SYMBOL(sram_free); | ||
49 | |||
50 | |||
51 | /* | ||
52 | * REVISIT This supports CPU and DMA access to/from SRAM, but it | ||
53 | * doesn't (yet?) support some other notable uses of SRAM: as TCM | ||
54 | * for data and/or instructions; and holding code needed to enter | ||
55 | * and exit suspend states (while DRAM can't be used). | ||
56 | */ | ||
57 | static int __init sram_init(void) | ||
58 | { | ||
59 | unsigned len = davinci_soc_info.sram_len; | ||
60 | int status = 0; | ||
61 | |||
62 | if (len) { | ||
63 | len = min(len, SRAM_SIZE); | ||
64 | sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); | ||
65 | if (!sram_pool) | ||
66 | status = -ENOMEM; | ||
67 | } | ||
68 | if (sram_pool) | ||
69 | status = gen_pool_add(sram_pool, SRAM_VIRT, len, -1); | ||
70 | WARN_ON(status < 0); | ||
71 | return status; | ||
72 | } | ||
73 | core_initcall(sram_init); | ||
74 | |||