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-rw-r--r--arch/arm/plat-omap/sram.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c
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1/*
2 * linux/arch/arm/plat-omap/sram.c
3 *
4 * OMAP SRAM detection and management
5 *
6 * Copyright (C) 2005 Nokia Corporation
7 * Written by Tony Lindgren <tony@atomide.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/config.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18
19#include <asm/mach/map.h>
20#include <asm/io.h>
21#include <asm/cacheflush.h>
22
23#include "sram.h"
24
25#define OMAP1_SRAM_BASE 0xd0000000
26#define OMAP1_SRAM_START 0x20000000
27#define SRAM_BOOTLOADER_SZ 0x80
28
29static unsigned long omap_sram_base;
30static unsigned long omap_sram_size;
31static unsigned long omap_sram_ceil;
32
33/*
34 * The amount of SRAM depends on the core type:
35 * 730 = 200K, 1510 = 512K, 5912 = 256K, 1610 = 16K, 1710 = 16K
36 * Note that we cannot try to test for SRAM here because writes
37 * to secure SRAM will hang the system. Also the SRAM is not
38 * yet mapped at this point.
39 */
40void __init omap_detect_sram(void)
41{
42 omap_sram_base = OMAP1_SRAM_BASE;
43
44 if (cpu_is_omap730())
45 omap_sram_size = 0x32000;
46 else if (cpu_is_omap1510())
47 omap_sram_size = 0x80000;
48 else if (cpu_is_omap1610() || cpu_is_omap1621() || cpu_is_omap1710())
49 omap_sram_size = 0x4000;
50 else if (cpu_is_omap1611())
51 omap_sram_size = 0x3e800;
52 else {
53 printk(KERN_ERR "Could not detect SRAM size\n");
54 omap_sram_size = 0x4000;
55 }
56
57 printk(KERN_INFO "SRAM size: 0x%lx\n", omap_sram_size);
58 omap_sram_ceil = omap_sram_base + omap_sram_size;
59}
60
61static struct map_desc omap_sram_io_desc[] __initdata = {
62 { OMAP1_SRAM_BASE, OMAP1_SRAM_START, 0, MT_DEVICE }
63};
64
65/*
66 * In order to use last 2kB of SRAM on 1611b, we must round the size
67 * up to multiple of PAGE_SIZE. We cannot use ioremap for SRAM, as
68 * clock init needs SRAM early.
69 */
70void __init omap_map_sram(void)
71{
72 if (omap_sram_size == 0)
73 return;
74
75 omap_sram_io_desc[0].length = (omap_sram_size + PAGE_SIZE-1)/PAGE_SIZE;
76 omap_sram_io_desc[0].length *= PAGE_SIZE;
77 iotable_init(omap_sram_io_desc, ARRAY_SIZE(omap_sram_io_desc));
78
79 /*
80 * Looks like we need to preserve some bootloader code at the
81 * beginning of SRAM for jumping to flash for reboot to work...
82 */
83 memset((void *)omap_sram_base + SRAM_BOOTLOADER_SZ, 0,
84 omap_sram_size - SRAM_BOOTLOADER_SZ);
85}
86
87static void (*_omap_sram_reprogram_clock)(u32 dpllctl, u32 ckctl) = NULL;
88
89void omap_sram_reprogram_clock(u32 dpllctl, u32 ckctl)
90{
91 if (_omap_sram_reprogram_clock == NULL)
92 panic("Cannot use SRAM");
93
94 return _omap_sram_reprogram_clock(dpllctl, ckctl);
95}
96
97void * omap_sram_push(void * start, unsigned long size)
98{
99 if (size > (omap_sram_ceil - (omap_sram_base + SRAM_BOOTLOADER_SZ))) {
100 printk(KERN_ERR "Not enough space in SRAM\n");
101 return NULL;
102 }
103 omap_sram_ceil -= size;
104 omap_sram_ceil &= ~0x3;
105 memcpy((void *)omap_sram_ceil, start, size);
106
107 return (void *)omap_sram_ceil;
108}
109
110void __init omap_sram_init(void)
111{
112 omap_detect_sram();
113 omap_map_sram();
114 _omap_sram_reprogram_clock = omap_sram_push(sram_reprogram_clock,
115 sram_reprogram_clock_sz);
116}