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 struct map_info uclinux_ram_map = { 27 .name = "RAM", 28 .phys = (unsigned long)__bss_stop, 29 .size = 0, 30 }; 31 32 static struct mtd_info *uclinux_ram_mtdinfo; 33 34 /****************************************************************************/ 35 36 static struct mtd_partition uclinux_romfs[] = { 37 { .name = "ROMfs" } 38 }; 39 40 #define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs) 41 42 /****************************************************************************/ 43 44 static int uclinux_point(struct mtd_info *mtd, loff_t from, size_t len, 45 size_t *retlen, void **virt, resource_size_t *phys) 46 { 47 struct map_info *map = mtd->priv; 48 *virt = map->virt + from; 49 if (phys) 50 *phys = map->phys + from; 51 *retlen = len; 52 return(0); 53 } 54 55 /****************************************************************************/ 56 57 static int __init uclinux_mtd_init(void) 58 { 59 struct mtd_info *mtd; 60 struct map_info *mapp; 61 62 mapp = &uclinux_ram_map; 63 if (!mapp->size) 64 mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8)))); 65 mapp->bankwidth = 4; 66 67 printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n", 68 (int) mapp->phys, (int) mapp->size); 69 70 /* 71 * The filesystem is guaranteed to be in direct mapped memory. It is 72 * directly following the kernels own bss region. Following the same 73 * mechanism used by architectures setting up traditional initrds we 74 * use phys_to_virt to get the virtual address of its start. 75 */ 76 mapp->virt = phys_to_virt(mapp->phys); 77 78 if (mapp->virt == 0) { 79 printk("uclinux[mtd]: no virtual mapping?\n"); 80 return(-EIO); 81 } 82 83 simple_map_init(mapp); 84 85 mtd = do_map_probe("map_ram", mapp); 86 if (!mtd) { 87 printk("uclinux[mtd]: failed to find a mapping?\n"); 88 return(-ENXIO); 89 } 90 91 mtd->owner = THIS_MODULE; 92 mtd->_point = uclinux_point; 93 mtd->priv = mapp; 94 95 uclinux_ram_mtdinfo = mtd; 96 mtd_device_register(mtd, uclinux_romfs, NUM_PARTITIONS); 97 98 return(0); 99 } 100 101 /****************************************************************************/ 102 103 static void __exit uclinux_mtd_cleanup(void) 104 { 105 if (uclinux_ram_mtdinfo) { 106 mtd_device_unregister(uclinux_ram_mtdinfo); 107 map_destroy(uclinux_ram_mtdinfo); 108 uclinux_ram_mtdinfo = NULL; 109 } 110 if (uclinux_ram_map.virt) 111 uclinux_ram_map.virt = 0; 112 } 113 114 /****************************************************************************/ 115 116 module_init(uclinux_mtd_init); 117 module_exit(uclinux_mtd_cleanup); 118 119 MODULE_LICENSE("GPL"); 120 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>"); 121 MODULE_DESCRIPTION("Generic RAM based MTD for uClinux"); 122 123 /****************************************************************************/ 124