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 */ 36 extern struct map_info uclinux_ram_map; 37 38 struct map_info uclinux_ram_map = { 39 .name = MAP_NAME, 40 .size = 0, 41 }; 42 43 static unsigned long physaddr = -1; 44 module_param(physaddr, ulong, S_IRUGO); 45 46 static struct mtd_info *uclinux_ram_mtdinfo; 47 48 /****************************************************************************/ 49 50 static struct mtd_partition uclinux_romfs[] = { 51 { .name = "ROMfs" } 52 }; 53 54 #define NUM_PARTITIONS ARRAY_SIZE(uclinux_romfs) 55 56 /****************************************************************************/ 57 58 static 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 71 static 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 /****************************************************************************/ 122 123 static 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 /****************************************************************************/ 135 136 module_init(uclinux_mtd_init); 137 module_exit(uclinux_mtd_cleanup); 138 139 MODULE_LICENSE("GPL"); 140 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>"); 141 MODULE_DESCRIPTION("Generic MTD for uClinux"); 142 143 /****************************************************************************/ 144