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 * License: GPL
9 */
10
11 /****************************************************************************/
12
13 #include <linux/moduleparam.h>
14 #include <linux/types.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/fs.h>
18 #include <linux/mm.h>
19 #include <linux/major.h>
20 #include <linux/mtd/mtd.h>
21 #include <linux/mtd/map.h>
22 #include <linux/mtd/partitions.h>
23 #include <asm/io.h>
24 #include <asm/sections.h>
25
26 /****************************************************************************/
27
28 #ifdef CONFIG_MTD_ROM
29 #define MAP_NAME "rom"
30 #else
31 #define MAP_NAME "ram"
32 #endif
33
34 static struct map_info uclinux_ram_map = {
35 .name = MAP_NAME,
36 .size = 0,
37 };
38
39 static unsigned long physaddr = -1;
40 module_param(physaddr, ulong, S_IRUGO);
41
42 static struct mtd_info *uclinux_ram_mtdinfo;
43
44 /****************************************************************************/
45
46 static const struct mtd_partition uclinux_romfs[] = {
47 { .name = "ROMfs" }
48 };
49
50 #define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs)
51
52 /****************************************************************************/
53
uclinux_point(struct mtd_info * mtd,loff_t from,size_t len,size_t * retlen,void ** virt,resource_size_t * phys)54 static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len,
55 size_t *retlen, void **virt, resource_size_t *phys)
56 {
57 struct map_info *map = mtd->priv;
58 *virt = map->virt + from;
59 if (phys)
60 *phys = map->phys + from;
61 *retlen = len;
62 return(0);
63 }
64
65 /****************************************************************************/
66
uclinux_mtd_init(void)67 static int __init uclinux_mtd_init(void)
68 {
69 struct mtd_info *mtd;
70 struct map_info *mapp;
71
72 mapp = &uclinux_ram_map;
73
74 if (physaddr == -1)
75 mapp->phys = (resource_size_t)__bss_stop;
76 else
77 mapp->phys = physaddr;
78
79 if (!mapp->size)
80 mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8))));
81 mapp->bankwidth = 4;
82
83 printk("uclinux[mtd]: probe address=0x%x size=0x%x\n",
84 (int) mapp->phys, (int) mapp->size);
85
86 /*
87 * The filesystem is guaranteed to be in direct mapped memory. It is
88 * directly following the kernels own bss region. Following the same
89 * mechanism used by architectures setting up traditional initrds we
90 * use phys_to_virt to get the virtual address of its start.
91 */
92 mapp->virt = phys_to_virt(mapp->phys);
93
94 if (mapp->virt == 0) {
95 printk("uclinux[mtd]: no virtual mapping?\n");
96 return(-EIO);
97 }
98
99 simple_map_init(mapp);
100
101 mtd = do_map_probe("map_" MAP_NAME, mapp);
102 if (!mtd) {
103 printk("uclinux[mtd]: failed to find a mapping?\n");
104 return(-ENXIO);
105 }
106
107 mtd->owner = THIS_MODULE;
108 mtd->_point = uclinux_point;
109 mtd->priv = mapp;
110
111 uclinux_ram_mtdinfo = mtd;
112 mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS);
113
114 return(0);
115 }
116 device_initcall(uclinux_mtd_init);
117
118 /****************************************************************************/
119