120e9969bSDavid Brownell /* 220e9969bSDavid Brownell * mach-davinci/sram.c - DaVinci simple SRAM allocator 320e9969bSDavid Brownell * 420e9969bSDavid Brownell * Copyright (C) 2009 David Brownell 520e9969bSDavid Brownell * 620e9969bSDavid Brownell * This program is free software; you can redistribute it and/or modify 720e9969bSDavid Brownell * it under the terms of the GNU General Public License as published by 820e9969bSDavid Brownell * the Free Software Foundation; either version 2 of the License, or 920e9969bSDavid Brownell * (at your option) any later version. 1020e9969bSDavid Brownell */ 1120e9969bSDavid Brownell #include <linux/module.h> 1220e9969bSDavid Brownell #include <linux/init.h> 13626863a3SBen Gardiner #include <linux/io.h> 1420e9969bSDavid Brownell #include <linux/genalloc.h> 1520e9969bSDavid Brownell 1620e9969bSDavid Brownell #include <mach/common.h> 17*3acf731cSArnd Bergmann #include "sram.h" 1820e9969bSDavid Brownell 1920e9969bSDavid Brownell static struct gen_pool *sram_pool; 2020e9969bSDavid Brownell 21983c42baSMatt Porter struct gen_pool *sram_get_gen_pool(void) 22983c42baSMatt Porter { 23983c42baSMatt Porter return sram_pool; 24983c42baSMatt Porter } 25983c42baSMatt Porter 2620e9969bSDavid Brownell void *sram_alloc(size_t len, dma_addr_t *dma) 2720e9969bSDavid Brownell { 2820e9969bSDavid Brownell dma_addr_t dma_base = davinci_soc_info.sram_dma; 2920e9969bSDavid Brownell 3020e9969bSDavid Brownell if (dma) 3120e9969bSDavid Brownell *dma = 0; 3220e9969bSDavid Brownell if (!sram_pool || (dma && !dma_base)) 3320e9969bSDavid Brownell return NULL; 3420e9969bSDavid Brownell 3566f11969SNicolin Chen return gen_pool_dma_alloc(sram_pool, len, dma); 3620e9969bSDavid Brownell 3720e9969bSDavid Brownell } 3820e9969bSDavid Brownell EXPORT_SYMBOL(sram_alloc); 3920e9969bSDavid Brownell 4020e9969bSDavid Brownell void sram_free(void *addr, size_t len) 4120e9969bSDavid Brownell { 4220e9969bSDavid Brownell gen_pool_free(sram_pool, (unsigned long) addr, len); 4320e9969bSDavid Brownell } 4420e9969bSDavid Brownell EXPORT_SYMBOL(sram_free); 4520e9969bSDavid Brownell 4620e9969bSDavid Brownell 4720e9969bSDavid Brownell /* 4820e9969bSDavid Brownell * REVISIT This supports CPU and DMA access to/from SRAM, but it 4920e9969bSDavid Brownell * doesn't (yet?) support some other notable uses of SRAM: as TCM 5020e9969bSDavid Brownell * for data and/or instructions; and holding code needed to enter 5120e9969bSDavid Brownell * and exit suspend states (while DRAM can't be used). 5220e9969bSDavid Brownell */ 5320e9969bSDavid Brownell static int __init sram_init(void) 5420e9969bSDavid Brownell { 55626863a3SBen Gardiner phys_addr_t phys = davinci_soc_info.sram_dma; 5620e9969bSDavid Brownell unsigned len = davinci_soc_info.sram_len; 5720e9969bSDavid Brownell int status = 0; 58182e7961SSekhar Nori void __iomem *addr; 5920e9969bSDavid Brownell 6020e9969bSDavid Brownell if (len) { 611d3bba61SDavid Brownell len = min_t(unsigned, len, SRAM_SIZE); 6220e9969bSDavid Brownell sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); 6320e9969bSDavid Brownell if (!sram_pool) 6420e9969bSDavid Brownell status = -ENOMEM; 6520e9969bSDavid Brownell } 66626863a3SBen Gardiner 67626863a3SBen Gardiner if (sram_pool) { 68626863a3SBen Gardiner addr = ioremap(phys, len); 69626863a3SBen Gardiner if (!addr) 70626863a3SBen Gardiner return -ENOMEM; 71182e7961SSekhar Nori status = gen_pool_add_virt(sram_pool, (unsigned long) addr, 72626863a3SBen Gardiner phys, len, -1); 73626863a3SBen Gardiner if (status < 0) 74626863a3SBen Gardiner iounmap(addr); 75626863a3SBen Gardiner } 76626863a3SBen Gardiner 7720e9969bSDavid Brownell WARN_ON(status < 0); 7820e9969bSDavid Brownell return status; 7920e9969bSDavid Brownell } 8020e9969bSDavid Brownell core_initcall(sram_init); 8120e9969bSDavid Brownell 82