projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 DB |
12 | #include <linux/init.h> |
| 13 | #include <linux/genalloc.h> | |
| 14 | ||
| 15 | #include <mach/common.h> | |
| 20e9969b DB |
16 | #include <mach/sram.h> |
| 17 | ||
| 20e9969b DB |
18 | static struct gen_pool *sram_pool; |
| 19 | ||
| 20 | void *sram_alloc(size_t len, dma_addr_t *dma) | |
| 21 | { | |
| 22 | unsigned long vaddr; | |
| 23 | dma_addr_t dma_base = davinci_soc_info.sram_dma; | |
| 24 | ||
| 25 | if (dma) | |
| 26 | *dma = 0; | |
| 27 | if (!sram_pool || (dma && !dma_base)) | |
| 28 | return NULL; | |
| 29 | ||
| 30 | vaddr = gen_pool_alloc(sram_pool, len); | |
| 31 | if (!vaddr) | |
| 32 | return NULL; | |
| 33 | ||
| 34 | if (dma) | |
| 35 | *dma = dma_base + (vaddr - SRAM_VIRT); | |
| 36 | return (void *)vaddr; | |
| 37 | ||
| 38 | } | |
| 39 | EXPORT_SYMBOL(sram_alloc); | |
| 40 | ||
| 41 | void sram_free(void *addr, size_t len) | |
| 42 | { | |
| 43 | gen_pool_free(sram_pool, (unsigned long) addr, len); | |
| 44 | } | |
| 45 | EXPORT_SYMBOL(sram_free); | |
| 46 | ||
| 47 | ||
| 48 | /* | |
| 49 | * REVISIT This supports CPU and DMA access to/from SRAM, but it | |
| 50 | * doesn't (yet?) support some other notable uses of SRAM: as TCM | |
| 51 | * for data and/or instructions; and holding code needed to enter | |
| 52 | * and exit suspend states (while DRAM can't be used). | |
| 53 | */ | |
| 54 | static int __init sram_init(void) | |
| 55 | { | |
| 56 | unsigned len = davinci_soc_info.sram_len; | |
| 57 | int status = 0; | |
| 58 | ||
| 59 | if (len) { | |
| 1d3bba61 | 60 | len = min_t(unsigned, len, SRAM_SIZE); |
| 20e9969b DB |
61 | sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); |
| 62 | if (!sram_pool) | |
| 63 | status = -ENOMEM; | |
| 64 | } | |
| 65 | if (sram_pool) | |
| 66 | status = gen_pool_add(sram_pool, SRAM_VIRT, len, -1); | |
| 67 | WARN_ON(status < 0); | |
| 68 | return status; | |
| 69 | } | |
| 70 | core_initcall(sram_init); | |
| 71 |