1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * mach-davinci/sram.c - DaVinci simple SRAM allocator
4 *
5 * Copyright (C) 2009 David Brownell
6 */
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/genalloc.h>
11
12#include "common.h"
13#include "sram.h"
14
15static struct gen_pool *sram_pool;
16
17struct gen_pool *sram_get_gen_pool(void)
18{
19	return sram_pool;
20}
21
22void *sram_alloc(size_t len, dma_addr_t *dma)
23{
24	dma_addr_t dma_base = davinci_soc_info.sram_dma;
25
26	if (dma)
27		*dma = 0;
28	if (!sram_pool || (dma && !dma_base))
29		return NULL;
30
31	return gen_pool_dma_alloc(sram_pool, len, dma);
32
33}
34EXPORT_SYMBOL(sram_alloc);
35
36void sram_free(void *addr, size_t len)
37{
38	gen_pool_free(sram_pool, (unsigned long) addr, len);
39}
40EXPORT_SYMBOL(sram_free);
41
42
43/*
44 * REVISIT This supports CPU and DMA access to/from SRAM, but it
45 * doesn't (yet?) support some other notable uses of SRAM:  as TCM
46 * for data and/or instructions; and holding code needed to enter
47 * and exit suspend states (while DRAM can't be used).
48 */
49static int __init sram_init(void)
50{
51	phys_addr_t phys = davinci_soc_info.sram_dma;
52	unsigned len = davinci_soc_info.sram_len;
53	int status = 0;
54	void __iomem *addr;
55
56	if (len) {
57		len = min_t(unsigned, len, SRAM_SIZE);
58		sram_pool = gen_pool_create(ilog2(SRAM_GRANULARITY), -1);
59		if (!sram_pool)
60			status = -ENOMEM;
61	}
62
63	if (sram_pool) {
64		addr = ioremap(phys, len);
65		if (!addr)
66			return -ENOMEM;
67		status = gen_pool_add_virt(sram_pool, (unsigned long) addr,
68					   phys, len, -1);
69		if (status < 0)
70			iounmap(addr);
71	}
72
73	WARN_ON(status < 0);
74	return status;
75}
76core_initcall(sram_init);
77
78