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/init.h> 13 #include <linux/io.h> 14 #include <linux/genalloc.h> 15 16 #include <mach/common.h> 17 #include "sram.h" 18 19 static struct gen_pool *sram_pool; 20 21 struct gen_pool *sram_get_gen_pool(void) 22 { 23 return sram_pool; 24 } 25 26 void *sram_alloc(size_t len, dma_addr_t *dma) 27 { 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 35 return gen_pool_dma_alloc(sram_pool, len, dma); 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 { 55 phys_addr_t phys = davinci_soc_info.sram_dma; 56 unsigned len = davinci_soc_info.sram_len; 57 int status = 0; 58 void __iomem *addr; 59 60 if (len) { 61 len = min_t(unsigned, len, SRAM_SIZE); 62 sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); 63 if (!sram_pool) 64 status = -ENOMEM; 65 } 66 67 if (sram_pool) { 68 addr = ioremap(phys, len); 69 if (!addr) 70 return -ENOMEM; 71 status = gen_pool_add_virt(sram_pool, (unsigned long) addr, 72 phys, len, -1); 73 if (status < 0) 74 iounmap(addr); 75 } 76 77 WARN_ON(status < 0); 78 return status; 79 } 80 core_initcall(sram_init); 81 82