drivers/mtd/devices/mtdram.c

   1 /*
   2  * mtdram - a test mtd device
   3  * $Id: mtdram.c,v 1.35 2005/01/05 18:05:12 dwmw2 Exp $
   4  * Author: Alexander Larsson <alex@cendio.se>
   5  *
   6  * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
   7  *
   8  * This code is GPL
   9  *
  10  */
  11
  12 #include <linux/config.h>
  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 #ifndef CONFIG_MTDRAM_ABS_POS
  22   #define CONFIG_MTDRAM_ABS_POS 0
  23 #endif
  24
  25 #if CONFIG_MTDRAM_ABS_POS > 0
  26   #include <asm/io.h>
  27 #endif
  28
  29 #ifdef MODULE
  30 static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
  31 static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
  32 module_param(total_size,ulong,0);
  33 MODULE_PARM_DESC(total_size, "Total device size in KiB");
  34 module_param(erase_size,ulong,0);
  35 MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
  36 #define MTDRAM_TOTAL_SIZE (total_size * 1024)
  37 #define MTDRAM_ERASE_SIZE (erase_size * 1024)
  38 #else
  39 #define MTDRAM_TOTAL_SIZE (CONFIG_MTDRAM_TOTAL_SIZE * 1024)
  40 #define MTDRAM_ERASE_SIZE (CONFIG_MTDRAM_ERASE_SIZE * 1024)
  41 #endif
  42
  43
  44 // We could store these in the mtd structure, but we only support 1 device..
  45 static struct mtd_info *mtd_info;
  46
  47
  48 static int
  49 ram_erase(struct mtd_info *mtd, struct erase_info *instr)
  50 {
  51   DEBUG(MTD_DEBUG_LEVEL2, "ram_erase(pos:%ld, len:%ld)\n", (long)instr->addr, (long)instr->len);
  52   if (instr->addr + instr->len > mtd->size) {
  53     DEBUG(MTD_DEBUG_LEVEL1, "ram_erase() out of bounds (%ld > %ld)\n", (long)(instr->addr + instr->len), (long)mtd->size);
  54     return -EINVAL;
  55   }
  56
  57   memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
  58
  59   instr->state = MTD_ERASE_DONE;
  60   mtd_erase_callback(instr);
  61
  62   return 0;
  63 }
  64
  65 static int ram_point (struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char **mtdbuf)
  66 {
  67   if (from + len > mtd->size)
  68     return -EINVAL;
  69
  70   *mtdbuf = mtd->priv + from;
  71   *retlen = len;
  72   return 0;
  73 }
  74
  75 static void ram_unpoint (struct mtd_info *mtd, u_char *addr, loff_t from,
  76                          size_t len)
  77 {
  78   DEBUG(MTD_DEBUG_LEVEL2, "ram_unpoint\n");
  79 }
  80
  81 static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
  82              size_t *retlen, u_char *buf)
  83 {
  84   DEBUG(MTD_DEBUG_LEVEL2, "ram_read(pos:%ld, len:%ld)\n", (long)from, (long)len);
  85   if (from + len > mtd->size) {
  86     DEBUG(MTD_DEBUG_LEVEL1, "ram_read() out of bounds (%ld > %ld)\n", (long)(from + len), (long)mtd->size);
  87     return -EINVAL;
  88   }
  89
  90   memcpy(buf, mtd->priv + from, len);
  91
  92   *retlen=len;
  93   return 0;
  94 }
  95
  96 static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
  97               size_t *retlen, const u_char *buf)
  98 {
  99   DEBUG(MTD_DEBUG_LEVEL2, "ram_write(pos:%ld, len:%ld)\n", (long)to, (long)len);
 100   if (to + len > mtd->size) {
 101     DEBUG(MTD_DEBUG_LEVEL1, "ram_write() out of bounds (%ld > %ld)\n", (long)(to + len), (long)mtd->size);
 102     return -EINVAL;
 103   }
 104
 105   memcpy ((char *)mtd->priv + to, buf, len);
 106
 107   *retlen=len;
 108   return 0;
 109 }
 110
 111 static void __exit cleanup_mtdram(void)
 112 {
 113   if (mtd_info) {
 114     del_mtd_device(mtd_info);
 115 #if CONFIG_MTDRAM_TOTAL_SIZE > 0
 116     if (mtd_info->priv)
 117 #if CONFIG_MTDRAM_ABS_POS > 0
 118       iounmap(mtd_info->priv);
 119 #else
 120       vfree(mtd_info->priv);
 121 #endif
 122 #endif
 123     kfree(mtd_info);
 124   }
 125 }
 126
 127 int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
 128                        unsigned long size, char *name)
 129 {
 130    memset(mtd, 0, sizeof(*mtd));
 131
 132    /* Setup the MTD structure */
 133    mtd->name = name;
 134    mtd->type = MTD_RAM;
 135    mtd->flags = MTD_CAP_RAM;
 136    mtd->size = size;
 137    mtd->erasesize = MTDRAM_ERASE_SIZE;
 138    mtd->priv = mapped_address;
 139
 140    mtd->owner = THIS_MODULE;
 141    mtd->erase = ram_erase;
 142    mtd->point = ram_point;
 143    mtd->unpoint = ram_unpoint;
 144    mtd->read = ram_read;
 145    mtd->write = ram_write;
 146
 147    if (add_mtd_device(mtd)) {
 148      return -EIO;
 149    }
 150
 151    return 0;
 152 }
 153
 154 #if CONFIG_MTDRAM_TOTAL_SIZE > 0
 155 #if CONFIG_MTDRAM_ABS_POS > 0
 156 static int __init init_mtdram(void)
 157 {
 158   void *addr;
 159   int err;
 160   /* Allocate some memory */
 161    mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
 162    if (!mtd_info)
 163      return -ENOMEM;
 164
 165   addr = ioremap(CONFIG_MTDRAM_ABS_POS, MTDRAM_TOTAL_SIZE);
 166   if (!addr) {
 167     DEBUG(MTD_DEBUG_LEVEL1,
 168           "Failed to ioremap) memory region of size %ld at ABS_POS:%ld\n",
 169           (long)MTDRAM_TOTAL_SIZE, (long)CONFIG_MTDRAM_ABS_POS);
 170     kfree(mtd_info);
 171     mtd_info = NULL;
 172     return -ENOMEM;
 173   }
 174   err = mtdram_init_device(mtd_info, addr,
 175                            MTDRAM_TOTAL_SIZE, "mtdram test device");
 176   if (err)
 177   {
 178     iounmap(addr);
 179     kfree(mtd_info);
 180     mtd_info = NULL;
 181     return err;
 182   }
 183   memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
 184   return err;
 185 }
 186
 187 #else /* CONFIG_MTDRAM_ABS_POS > 0 */
 188
 189 static int __init init_mtdram(void)
 190 {
 191   void *addr;
 192   int err;
 193   /* Allocate some memory */
 194    mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
 195    if (!mtd_info)
 196      return -ENOMEM;
 197
 198   addr = vmalloc(MTDRAM_TOTAL_SIZE);
 199   if (!addr) {
 200     DEBUG(MTD_DEBUG_LEVEL1,
 201           "Failed to vmalloc memory region of size %ld\n",
 202           (long)MTDRAM_TOTAL_SIZE);
 203     kfree(mtd_info);
 204     mtd_info = NULL;
 205     return -ENOMEM;
 206   }
 207   err = mtdram_init_device(mtd_info, addr,
 208                            MTDRAM_TOTAL_SIZE, "mtdram test device");
 209   if (err)
 210   {
 211     vfree(addr);
 212     kfree(mtd_info);
 213     mtd_info = NULL;
 214     return err;
 215   }
 216   memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
 217   return err;
 218 }
 219 #endif /* !(CONFIG_MTDRAM_ABS_POS > 0) */
 220
 221 #else /* CONFIG_MTDRAM_TOTAL_SIZE > 0 */
 222
 223 static int __init init_mtdram(void)
 224 {
 225   return 0;
 226 }
 227 #endif /* !(CONFIG_MTDRAM_TOTAL_SIZE > 0) */
 228
 229 module_init(init_mtdram);
 230 module_exit(cleanup_mtdram);
 231
 232 MODULE_LICENSE("GPL");
 233 MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
 234 MODULE_DESCRIPTION("Simulated MTD driver for testing");
 235