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 | |
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 | |
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(address: 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(name: "map_" MAP_NAME, map: 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 | |