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 <mach/sram.h>
18
19static struct gen_pool *sram_pool;
20
21struct gen_pool *sram_get_gen_pool(void)
22{
23	return sram_pool;
24}
25
26void *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}
38EXPORT_SYMBOL(sram_alloc);
39
40void sram_free(void *addr, size_t len)
41{
42	gen_pool_free(sram_pool, (unsigned long) addr, len);
43}
44EXPORT_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 */
53static 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}
80core_initcall(sram_init);
81
82