1*20e9969bSDavid Brownell /* 2*20e9969bSDavid Brownell * mach-davinci/sram.c - DaVinci simple SRAM allocator 3*20e9969bSDavid Brownell * 4*20e9969bSDavid Brownell * Copyright (C) 2009 David Brownell 5*20e9969bSDavid Brownell * 6*20e9969bSDavid Brownell * This program is free software; you can redistribute it and/or modify 7*20e9969bSDavid Brownell * it under the terms of the GNU General Public License as published by 8*20e9969bSDavid Brownell * the Free Software Foundation; either version 2 of the License, or 9*20e9969bSDavid Brownell * (at your option) any later version. 10*20e9969bSDavid Brownell */ 11*20e9969bSDavid Brownell #include <linux/module.h> 12*20e9969bSDavid Brownell #include <linux/kernel.h> 13*20e9969bSDavid Brownell #include <linux/init.h> 14*20e9969bSDavid Brownell #include <linux/genalloc.h> 15*20e9969bSDavid Brownell 16*20e9969bSDavid Brownell #include <mach/common.h> 17*20e9969bSDavid Brownell #include <mach/memory.h> 18*20e9969bSDavid Brownell #include <mach/sram.h> 19*20e9969bSDavid Brownell 20*20e9969bSDavid Brownell 21*20e9969bSDavid Brownell static struct gen_pool *sram_pool; 22*20e9969bSDavid Brownell 23*20e9969bSDavid Brownell void *sram_alloc(size_t len, dma_addr_t *dma) 24*20e9969bSDavid Brownell { 25*20e9969bSDavid Brownell unsigned long vaddr; 26*20e9969bSDavid Brownell dma_addr_t dma_base = davinci_soc_info.sram_dma; 27*20e9969bSDavid Brownell 28*20e9969bSDavid Brownell if (dma) 29*20e9969bSDavid Brownell *dma = 0; 30*20e9969bSDavid Brownell if (!sram_pool || (dma && !dma_base)) 31*20e9969bSDavid Brownell return NULL; 32*20e9969bSDavid Brownell 33*20e9969bSDavid Brownell vaddr = gen_pool_alloc(sram_pool, len); 34*20e9969bSDavid Brownell if (!vaddr) 35*20e9969bSDavid Brownell return NULL; 36*20e9969bSDavid Brownell 37*20e9969bSDavid Brownell if (dma) 38*20e9969bSDavid Brownell *dma = dma_base + (vaddr - SRAM_VIRT); 39*20e9969bSDavid Brownell return (void *)vaddr; 40*20e9969bSDavid Brownell 41*20e9969bSDavid Brownell } 42*20e9969bSDavid Brownell EXPORT_SYMBOL(sram_alloc); 43*20e9969bSDavid Brownell 44*20e9969bSDavid Brownell void sram_free(void *addr, size_t len) 45*20e9969bSDavid Brownell { 46*20e9969bSDavid Brownell gen_pool_free(sram_pool, (unsigned long) addr, len); 47*20e9969bSDavid Brownell } 48*20e9969bSDavid Brownell EXPORT_SYMBOL(sram_free); 49*20e9969bSDavid Brownell 50*20e9969bSDavid Brownell 51*20e9969bSDavid Brownell /* 52*20e9969bSDavid Brownell * REVISIT This supports CPU and DMA access to/from SRAM, but it 53*20e9969bSDavid Brownell * doesn't (yet?) support some other notable uses of SRAM: as TCM 54*20e9969bSDavid Brownell * for data and/or instructions; and holding code needed to enter 55*20e9969bSDavid Brownell * and exit suspend states (while DRAM can't be used). 56*20e9969bSDavid Brownell */ 57*20e9969bSDavid Brownell static int __init sram_init(void) 58*20e9969bSDavid Brownell { 59*20e9969bSDavid Brownell unsigned len = davinci_soc_info.sram_len; 60*20e9969bSDavid Brownell int status = 0; 61*20e9969bSDavid Brownell 62*20e9969bSDavid Brownell if (len) { 63*20e9969bSDavid Brownell len = min(len, SRAM_SIZE); 64*20e9969bSDavid Brownell sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); 65*20e9969bSDavid Brownell if (!sram_pool) 66*20e9969bSDavid Brownell status = -ENOMEM; 67*20e9969bSDavid Brownell } 68*20e9969bSDavid Brownell if (sram_pool) 69*20e9969bSDavid Brownell status = gen_pool_add(sram_pool, SRAM_VIRT, len, -1); 70*20e9969bSDavid Brownell WARN_ON(status < 0); 71*20e9969bSDavid Brownell return status; 72*20e9969bSDavid Brownell } 73*20e9969bSDavid Brownell core_initcall(sram_init); 74*20e9969bSDavid Brownell 75