uclinux.c (2911B)
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 34static struct map_info uclinux_ram_map = { 35 .name = MAP_NAME, 36 .size = 0, 37}; 38 39static unsigned long physaddr = -1; 40module_param(physaddr, ulong, S_IRUGO); 41 42static struct mtd_info *uclinux_ram_mtdinfo; 43 44/****************************************************************************/ 45 46static const struct mtd_partition uclinux_romfs[] = { 47 { .name = "ROMfs" } 48}; 49 50#define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs) 51 52/****************************************************************************/ 53 54static 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 67static 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} 116device_initcall(uclinux_mtd_init); 117 118/****************************************************************************/