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Diffstat (limited to 'arch/arm/mach-davinci/sram.c')
-rw-r--r-- | arch/arm/mach-davinci/sram.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/sram.c b/arch/arm/mach-davinci/sram.c new file mode 100644 index 000000000..8540dddf1 --- /dev/null +++ b/arch/arm/mach-davinci/sram.c @@ -0,0 +1,81 @@ +/* + * mach-davinci/sram.c - DaVinci simple SRAM allocator + * + * Copyright (C) 2009 David Brownell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/genalloc.h> + +#include <mach/common.h> +#include <mach/sram.h> + +static struct gen_pool *sram_pool; + +struct gen_pool *sram_get_gen_pool(void) +{ + return sram_pool; +} + +void *sram_alloc(size_t len, dma_addr_t *dma) +{ + dma_addr_t dma_base = davinci_soc_info.sram_dma; + + if (dma) + *dma = 0; + if (!sram_pool || (dma && !dma_base)) + return NULL; + + return gen_pool_dma_alloc(sram_pool, len, dma); + +} +EXPORT_SYMBOL(sram_alloc); + +void sram_free(void *addr, size_t len) +{ + gen_pool_free(sram_pool, (unsigned long) addr, len); +} +EXPORT_SYMBOL(sram_free); + + +/* + * REVISIT This supports CPU and DMA access to/from SRAM, but it + * doesn't (yet?) support some other notable uses of SRAM: as TCM + * for data and/or instructions; and holding code needed to enter + * and exit suspend states (while DRAM can't be used). + */ +static int __init sram_init(void) +{ + phys_addr_t phys = davinci_soc_info.sram_dma; + unsigned len = davinci_soc_info.sram_len; + int status = 0; + void __iomem *addr; + + if (len) { + len = min_t(unsigned, len, SRAM_SIZE); + sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1); + if (!sram_pool) + status = -ENOMEM; + } + + if (sram_pool) { + addr = ioremap(phys, len); + if (!addr) + return -ENOMEM; + status = gen_pool_add_virt(sram_pool, (unsigned long) addr, + phys, len, -1); + if (status < 0) + iounmap(addr); + } + + WARN_ON(status < 0); + return status; +} +core_initcall(sram_init); + |