drivers/mtd/maps/db1550-flash.c

   1 /*
   2  * Flash memory access on Alchemy Db1550 board
   3  *
   4  * $Id: db1550-flash.c,v 1.7 2004/11/04 13:24:14 gleixner Exp $
   5  *
   6  * (C) 2004 Embedded Edge, LLC, based on db1550-flash.c:
   7  * (C) 2003, 2004 Pete Popov <ppopov@embeddedalley.com>
   8  *
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/kernel.h>
  16
  17 #include <linux/mtd/mtd.h>
  18 #include <linux/mtd/map.h>
  19 #include <linux/mtd/partitions.h>
  20
  21 #include <asm/io.h>
  22
  23 #ifdef  DEBUG_RW
  24 #define DBG(x...)       printk(x)
  25 #else
  26 #define DBG(x...)
  27 #endif
  28
  29 static unsigned long window_addr;
  30 static unsigned long window_size;
  31
  32
  33 static struct map_info db1550_map = {
  34         .name = "Db1550 flash",
  35 };
  36
  37 static unsigned char flash_bankwidth = 4;
  38
  39 /*
  40  * Support only 64MB NOR Flash parts
  41  */
  42
  43 #if defined(CONFIG_MTD_DB1550_BOOT) && defined(CONFIG_MTD_DB1550_USER)
  44 #define DB1550_BOTH_BANKS
  45 #elif defined(CONFIG_MTD_DB1550_BOOT) && !defined(CONFIG_MTD_DB1550_USER)
  46 #define DB1550_BOOT_ONLY
  47 #elif !defined(CONFIG_MTD_DB1550_BOOT) && defined(CONFIG_MTD_DB1550_USER)
  48 #define DB1550_USER_ONLY
  49 #endif
  50
  51 #ifdef DB1550_BOTH_BANKS
  52 /* both banks will be used. Combine the first bank and the first
  53  * part of the second bank together into a single jffs/jffs2
  54  * partition.
  55  */
  56 static struct mtd_partition db1550_partitions[] = {
  57         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  58          * 1C00 0000 1FFF FFFF CE0 64MB Boot NOR Flash
  59          * 1800 0000 1BFF FFFF CE0 64MB Param NOR Flash
  60          */
  61         {
  62                 .name = "User FS",
  63                 .size =   (0x1FC00000 - 0x18000000),
  64                 .offset = 0x0000000
  65         },{
  66                 .name = "yamon",
  67                 .size = 0x0100000,
  68                 .offset = MTDPART_OFS_APPEND,
  69                 .mask_flags = MTD_WRITEABLE
  70         },{
  71                 .name = "raw kernel",
  72                 .size = (0x300000 - 0x40000), /* last 256KB is yamon env */
  73                 .offset = MTDPART_OFS_APPEND,
  74         }
  75 };
  76 #elif defined(DB1550_BOOT_ONLY)
  77 static struct mtd_partition db1550_partitions[] = {
  78         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  79          * 1C00 0000 1FFF FFFF CE0 64MB Boot NOR Flash
  80          */
  81         {
  82                 .name = "User FS",
  83                 .size =   0x03c00000,
  84                 .offset = 0x0000000
  85         },{
  86                 .name = "yamon",
  87                 .size = 0x0100000,
  88                 .offset = MTDPART_OFS_APPEND,
  89                 .mask_flags = MTD_WRITEABLE
  90         },{
  91                 .name = "raw kernel",
  92                 .size = (0x300000-0x40000), /* last 256KB is yamon env */
  93                 .offset = MTDPART_OFS_APPEND,
  94         }
  95 };
  96 #elif defined(DB1550_USER_ONLY)
  97 static struct mtd_partition db1550_partitions[] = {
  98         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  99          * 1800 0000 1BFF FFFF CE0 64MB Param NOR Flash
 100          */
 101         {
 102                 .name = "User FS",
 103                 .size = (0x4000000 - 0x200000), /* reserve 2MB for raw kernel */
 104                 .offset = 0x0000000
 105         },{
 106                 .name = "raw kernel",
 107                 .size = MTDPART_SIZ_FULL,
 108                 .offset = MTDPART_OFS_APPEND,
 109         }
 110 };
 111 #else
 112 #error MTD_DB1550 define combo error /* should never happen */
 113 #endif
 114
 115 #define NB_OF(x)  (sizeof(x)/sizeof(x[0]))
 116
 117 static struct mtd_info *mymtd;
 118
 119 /*
 120  * Probe the flash density and setup window address and size
 121  * based on user CONFIG options. There are times when we don't
 122  * want the MTD driver to be probing the boot or user flash,
 123  * so having the option to enable only one bank is important.
 124  */
 125 int setup_flash_params(void)
 126 {
 127 #if defined(DB1550_BOTH_BANKS)
 128                         window_addr = 0x18000000;
 129                         window_size = 0x8000000;
 130 #elif defined(DB1550_BOOT_ONLY)
 131                         window_addr = 0x1C000000;
 132                         window_size = 0x4000000;
 133 #else /* USER ONLY */
 134                         window_addr = 0x18000000;
 135                         window_size = 0x4000000;
 136 #endif
 137         return 0;
 138 }
 139
 140 int __init db1550_mtd_init(void)
 141 {
 142         struct mtd_partition *parts;
 143         int nb_parts = 0;
 144
 145         /* Default flash bankwidth */
 146         db1550_map.bankwidth = flash_bankwidth;
 147
 148         if (setup_flash_params())
 149                 return -ENXIO;
 150
 151         /*
 152          * Static partition definition selection
 153          */
 154         parts = db1550_partitions;
 155         nb_parts = NB_OF(db1550_partitions);
 156         db1550_map.size = window_size;
 157
 158         /*
 159          * Now let's probe for the actual flash.  Do it here since
 160          * specific machine settings might have been set above.
 161          */
 162         printk(KERN_NOTICE "Db1550 flash: probing %d-bit flash bus\n",
 163                         db1550_map.bankwidth*8);
 164         db1550_map.virt = ioremap(window_addr, window_size);
 165         mymtd = do_map_probe("cfi_probe", &db1550_map);
 166         if (!mymtd) return -ENXIO;
 167         mymtd->owner = THIS_MODULE;
 168
 169         add_mtd_partitions(mymtd, parts, nb_parts);
 170         return 0;
 171 }
 172
 173 static void __exit db1550_mtd_cleanup(void)
 174 {
 175         if (mymtd) {
 176                 del_mtd_partitions(mymtd);
 177                 map_destroy(mymtd);
 178                 iounmap((void *) db1550_map.virt);
 179         }
 180 }
 181
 182 module_init(db1550_mtd_init);
 183 module_exit(db1550_mtd_cleanup);
 184
 185 MODULE_AUTHOR("Embedded Edge, LLC");
 186 MODULE_DESCRIPTION("Db1550 mtd map driver");
 187 MODULE_LICENSE("GPL");