drivers/mtd/maps/pb1550-flash.c

   1 /*
   2  * Flash memory access on Alchemy Pb1550 board
   3  *
   4  * $Id: pb1550-flash.c,v 1.6 2004/11/04 13:24:15 gleixner Exp $
   5  *
   6  * (C) 2004 Embedded Edge, LLC, based on pb1550-flash.c:
   7  * (C) 2003 Pete Popov <ppopov@pacbell.net>
   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 #include <asm/au1000.h>
  23 #include <asm/pb1550.h>
  24
  25 #ifdef  DEBUG_RW
  26 #define DBG(x...)       printk(x)
  27 #else
  28 #define DBG(x...)
  29 #endif
  30
  31 static unsigned long window_addr;
  32 static unsigned long window_size;
  33
  34
  35 static struct map_info pb1550_map = {
  36         .name = "Pb1550 flash",
  37 };
  38
  39 static unsigned char flash_bankwidth = 4;
  40
  41 /*
  42  * Support only 64MB NOR Flash parts
  43  */
  44
  45 #ifdef PB1550_BOTH_BANKS
  46 /* both banks will be used. Combine the first bank and the first
  47  * part of the second bank together into a single jffs/jffs2
  48  * partition.
  49  */
  50 static struct mtd_partition pb1550_partitions[] = {
  51         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  52          * 1C00 0000 1FFF FFFF CE0 64MB Boot NOR Flash
  53          * 1800 0000 1BFF FFFF CE0 64MB Param NOR Flash
  54          */
  55         {
  56                 .name = "User FS",
  57                 .size =   (0x1FC00000 - 0x18000000),
  58                 .offset = 0x0000000
  59         },{
  60                 .name = "yamon",
  61                 .size = 0x0100000,
  62                 .offset = MTDPART_OFS_APPEND,
  63                 .mask_flags = MTD_WRITEABLE
  64         },{
  65                 .name = "raw kernel",
  66                 .size = (0x300000 - 0x40000), /* last 256KB is yamon env */
  67                 .offset = MTDPART_OFS_APPEND,
  68         }
  69 };
  70 #elif defined(PB1550_BOOT_ONLY)
  71 static struct mtd_partition pb1550_partitions[] = {
  72         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  73          * 1C00 0000 1FFF FFFF CE0 64MB Boot NOR Flash
  74          */
  75         {
  76                 .name = "User FS",
  77                 .size =   0x03c00000,
  78                 .offset = 0x0000000
  79         },{
  80                 .name = "yamon",
  81                 .size = 0x0100000,
  82                 .offset = MTDPART_OFS_APPEND,
  83                 .mask_flags = MTD_WRITEABLE
  84         },{
  85                 .name = "raw kernel",
  86                 .size = (0x300000-0x40000), /* last 256KB is yamon env */
  87                 .offset = MTDPART_OFS_APPEND,
  88         }
  89 };
  90 #elif defined(PB1550_USER_ONLY)
  91 static struct mtd_partition pb1550_partitions[] = {
  92         /* assume boot[2:0]:swap is '0000' or '1000', which translates to:
  93          * 1800 0000 1BFF FFFF CE0 64MB Param NOR Flash
  94          */
  95         {
  96                 .name = "User FS",
  97                 .size = (0x4000000 - 0x200000), /* reserve 2MB for raw kernel */
  98                 .offset = 0x0000000
  99         },{
 100                 .name = "raw kernel",
 101                 .size = MTDPART_SIZ_FULL,
 102                 .offset = MTDPART_OFS_APPEND,
 103         }
 104 };
 105 #else
 106 #error MTD_PB1550 define combo error /* should never happen */
 107 #endif
 108
 109 #define NB_OF(x)  (sizeof(x)/sizeof(x[0]))
 110
 111 static struct mtd_info *mymtd;
 112
 113 /*
 114  * Probe the flash density and setup window address and size
 115  * based on user CONFIG options. There are times when we don't
 116  * want the MTD driver to be probing the boot or user flash,
 117  * so having the option to enable only one bank is important.
 118  */
 119 int setup_flash_params(void)
 120 {
 121         u16 boot_swapboot;
 122         boot_swapboot = (au_readl(MEM_STSTAT) & (0x7<<1)) |
 123                 ((bcsr->status >> 6)  & 0x1);
 124         printk("Pb1550 MTD: boot:swap %d\n", boot_swapboot);
 125
 126         switch (boot_swapboot) {
 127                 case 0: /* 512Mbit devices, both enabled */
 128                 case 1:
 129                 case 8:
 130                 case 9:
 131 #if defined(PB1550_BOTH_BANKS)
 132                         window_addr = 0x18000000;
 133                         window_size = 0x8000000;
 134 #elif defined(PB1550_BOOT_ONLY)
 135                         window_addr = 0x1C000000;
 136                         window_size = 0x4000000;
 137 #else /* USER ONLY */
 138                         window_addr = 0x1E000000;
 139                         window_size = 0x4000000;
 140 #endif
 141                         break;
 142                 case 0xC:
 143                 case 0xD:
 144                 case 0xE:
 145                 case 0xF:
 146                         /* 64 MB Boot NOR Flash is disabled */
 147                         /* and the start address is moved to 0x0C00000 */
 148                         window_addr = 0x0C000000;
 149                         window_size = 0x4000000;
 150                 default:
 151                         printk("Pb1550 MTD: unsupported boot:swap setting\n");
 152                         return 1;
 153         }
 154         return 0;
 155 }
 156
 157 int __init pb1550_mtd_init(void)
 158 {
 159         struct mtd_partition *parts;
 160         int nb_parts = 0;
 161
 162         /* Default flash bankwidth */
 163         pb1550_map.bankwidth = flash_bankwidth;
 164
 165         if (setup_flash_params())
 166                 return -ENXIO;
 167
 168         /*
 169          * Static partition definition selection
 170          */
 171         parts = pb1550_partitions;
 172         nb_parts = NB_OF(pb1550_partitions);
 173         pb1550_map.size = window_size;
 174
 175         /*
 176          * Now let's probe for the actual flash.  Do it here since
 177          * specific machine settings might have been set above.
 178          */
 179         printk(KERN_NOTICE "Pb1550 flash: probing %d-bit flash bus\n",
 180                         pb1550_map.bankwidth*8);
 181         pb1550_map.virt = ioremap(window_addr, window_size);
 182         mymtd = do_map_probe("cfi_probe", &pb1550_map);
 183         if (!mymtd) return -ENXIO;
 184         mymtd->owner = THIS_MODULE;
 185
 186         add_mtd_partitions(mymtd, parts, nb_parts);
 187         return 0;
 188 }
 189
 190 static void __exit pb1550_mtd_cleanup(void)
 191 {
 192         if (mymtd) {
 193                 del_mtd_partitions(mymtd);
 194                 map_destroy(mymtd);
 195         }
 196 }
 197
 198 module_init(pb1550_mtd_init);
 199 module_exit(pb1550_mtd_cleanup);
 200
 201 MODULE_AUTHOR("Embedded Edge, LLC");
 202 MODULE_DESCRIPTION("Pb1550 mtd map driver");
 203 MODULE_LICENSE("GPL");