drivers/mtd/devices/mtdram.c

   1 /*
   2  * mtdram - a test mtd device
   3  * $Id: mtdram.c,v 1.37 2005/04/21 03:42:11 joern Exp $
   4  * Author: Alexander Larsson <alex@cendio.se>
   5  *
   6  * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
   7  * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
   8  *
   9  * This code is GPL
  10  *
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/ioport.h>
  16 #include <linux/vmalloc.h>
  17 #include <linux/init.h>
  18 #include <linux/mtd/compatmac.h>
  19 #include <linux/mtd/mtd.h>
  20
  21 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
  22 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
  23 #define MTDRAM_TOTAL_SIZE (total_size * 1024)
  24 #define MTDRAM_ERASE_SIZE (erase_size * 1024)
  25
  26 #ifdef MODULE
  27 module_param(total_size, ulong, 0);
  28 MODULE_PARM_DESC(total_size, "Total device size in KiB");
  29 module_param(erase_size, ulong, 0);
  30 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
  31 #endif
  32
  33 // We could store these in the mtd structure, but we only support 1 device..
  34 static struct mtd_info *mtd_info;
  35
  36 static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
  37 {
  38         if (instr->addr + instr->len > mtd->size)
  39                 return -EINVAL;
  40
  41         memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
  42
  43         instr->state = MTD_ERASE_DONE;
  44         mtd_erase_callback(instr);
  45
  46         return 0;
  47 }
  48
  49 static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
  50                 size_t *retlen, u_char **mtdbuf)
  51 {
  52         if (from + len > mtd->size)
  53                 return -EINVAL;
  54
  55         *mtdbuf = mtd->priv + from;
  56         *retlen = len;
  57         return 0;
  58 }
  59
  60 static void ram_unpoint(struct mtd_info *mtd, u_char * addr, loff_t from,
  61                 size_t len)
  62 {
  63 }
  64
  65 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
  66                 size_t *retlen, u_char *buf)
  67 {
  68         if (from + len > mtd->size)
  69                 return -EINVAL;
  70
  71         memcpy(buf, mtd->priv + from, len);
  72
  73         *retlen = len;
  74         return 0;
  75 }
  76
  77 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
  78                 size_t *retlen, const u_char *buf)
  79 {
  80         if (to + len > mtd->size)
  81                 return -EINVAL;
  82
  83         memcpy((char *)mtd->priv + to, buf, len);
  84
  85         *retlen = len;
  86         return 0;
  87 }
  88
  89 static void __exit cleanup_mtdram(void)
  90 {
  91         if (mtd_info) {
  92                 del_mtd_device(mtd_info);
  93                 vfree(mtd_info->priv);
  94                 kfree(mtd_info);
  95         }
  96 }
  97
  98 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
  99                 unsigned long size, char *name)
 100 {
 101         memset(mtd, 0, sizeof(*mtd));
 102
 103         /* Setup the MTD structure */
 104         mtd->name = name;
 105         mtd->type = MTD_RAM;
 106         mtd->flags = MTD_CAP_RAM;
 107         mtd->size = size;
 108         mtd->writesize = 1;
 109         mtd->erasesize = MTDRAM_ERASE_SIZE;
 110         mtd->priv = mapped_address;
 111
 112         mtd->owner = THIS_MODULE;
 113         mtd->erase = ram_erase;
 114         mtd->point = ram_point;
 115         mtd->unpoint = ram_unpoint;
 116         mtd->read = ram_read;
 117         mtd->write = ram_write;
 118
 119         if (add_mtd_device(mtd)) {
 120                 return -EIO;
 121         }
 122
 123         return 0;
 124 }
 125
 126 static int __init init_mtdram(void)
 127 {
 128         void *addr;
 129         int err;
 130
 131         if (!total_size)
 132                 return -EINVAL;
 133
 134         /* Allocate some memory */
 135         mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
 136         if (!mtd_info)
 137                 return -ENOMEM;
 138
 139         addr = vmalloc(MTDRAM_TOTAL_SIZE);
 140         if (!addr) {
 141                 kfree(mtd_info);
 142                 mtd_info = NULL;
 143                 return -ENOMEM;
 144         }
 145         err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
 146         if (err) {
 147                 vfree(addr);
 148                 kfree(mtd_info);
 149                 mtd_info = NULL;
 150                 return err;
 151         }
 152         memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
 153         return err;
 154 }
 155
 156 module_init(init_mtdram);
 157 module_exit(cleanup_mtdram);
 158
 159 MODULE_LICENSE("GPL");
 160 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
 161 MODULE_DESCRIPTION("Simulated MTD driver for testing");