1/****************************************************************************/
2
3/*
4 *	uclinux.c -- generic memory mapped MTD driver for uclinux
5 *
6 *	(C) Copyright 2002, Greg Ungerer (gerg@snapgear.com)
7 */
8
9/****************************************************************************/
10
11#include <linux/module.h>
12#include <linux/types.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/fs.h>
16#include <linux/mm.h>
17#include <linux/major.h>
18#include <linux/mtd/mtd.h>
19#include <linux/mtd/map.h>
20#include <linux/mtd/partitions.h>
21#include <asm/io.h>
22#include <asm/sections.h>
23
24/****************************************************************************/
25
26#ifdef CONFIG_MTD_ROM
27#define MAP_NAME "rom"
28#else
29#define MAP_NAME "ram"
30#endif
31
32/*
33 * Blackfin uses uclinux_ram_map during startup, so it must not be static.
34 * Provide a dummy declaration to make sparse happy.
35 */
36extern struct map_info uclinux_ram_map;
37
38struct map_info uclinux_ram_map = {
39	.name = MAP_NAME,
40	.size = 0,
41};
42
43static unsigned long physaddr = -1;
44module_param(physaddr, ulong, S_IRUGO);
45
46static struct mtd_info *uclinux_ram_mtdinfo;
47
48/****************************************************************************/
49
50static struct mtd_partition uclinux_romfs[] = {
51	{ .name = "ROMfs" }
52};
53
54#define	NUM_PARTITIONS	ARRAY_SIZE(uclinux_romfs)
55
56/****************************************************************************/
57
58static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
59	size_t *retlen, void **virt, resource_size_t *phys)
60{
61	struct map_info *map = mtd->priv;
62	*virt = map->virt + from;
63	if (phys)
64		*phys = map->phys + from;
65	*retlen = len;
66	return(0);
67}
68
69/****************************************************************************/
70
71static int __init uclinux_mtd_init(void)
72{
73	struct mtd_info *mtd;
74	struct map_info *mapp;
75
76	mapp = &uclinux_ram_map;
77
78	if (physaddr == -1)
79		mapp->phys = (resource_size_t)__bss_stop;
80	else
81		mapp->phys = physaddr;
82
83	if (!mapp->size)
84		mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
85	mapp->bankwidth = 4;
86
87	printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
88	       	(int) mapp->phys, (int) mapp->size);
89
90	/*
91	 * The filesystem is guaranteed to be in direct mapped memory. It is
92	 * directly following the kernels own bss region. Following the same
93	 * mechanism used by architectures setting up traditional initrds we
94	 * use phys_to_virt to get the virtual address of its start.
95	 */
96	mapp->virt = phys_to_virt(mapp->phys);
97
98	if (mapp->virt == 0) {
99		printk("uclinux[mtd]: no virtual mapping?\n");
100		return(-EIO);
101	}
102
103	simple_map_init(mapp);
104
105	mtd = do_map_probe("map_" MAP_NAME, mapp);
106	if (!mtd) {
107		printk("uclinux[mtd]: failed to find a mapping?\n");
108		return(-ENXIO);
109	}
110
111	mtd->owner = THIS_MODULE;
112	mtd->_point = uclinux_point;
113	mtd->priv = mapp;
114
115	uclinux_ram_mtdinfo = mtd;
116	mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
117
118	return(0);
119}
120
121/****************************************************************************/
122
123static void __exit uclinux_mtd_cleanup(void)
124{
125	if (uclinux_ram_mtdinfo) {
126		mtd_device_unregister(uclinux_ram_mtdinfo);
127		map_destroy(uclinux_ram_mtdinfo);
128		uclinux_ram_mtdinfo = NULL;
129	}
130	if (uclinux_ram_map.virt)
131		uclinux_ram_map.virt = 0;
132}
133
134/****************************************************************************/
135
136module_init(uclinux_mtd_init);
137module_exit(uclinux_mtd_cleanup);
138
139MODULE_LICENSE("GPL");
140MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
141MODULE_DESCRIPTION("Generic MTD for uClinux");
142
143/****************************************************************************/
144