drivers/mtd/maps/tsunami_flash.c

   1 /*
   2  * tsunami_flash.c
   3  *
   4  * flash chip on alpha ds10...
   5  */
   6 #include <asm/io.h>
   7 #include <asm/core_tsunami.h>
   8 #include <linux/init.h>
   9 #include <linux/mtd/map.h>
  10 #include <linux/mtd/mtd.h>
  11
  12 #define FLASH_ENABLE_PORT 0x00C00001
  13 #define FLASH_ENABLE_BYTE 0x01
  14 #define FLASH_DISABLE_BYTE 0x00
  15
  16 #define MAX_TIG_FLASH_SIZE (12*1024*1024)
  17 static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset)
  18 {
  19         map_word val;
  20         val.x[0] = tsunami_tig_readb(offset);
  21         return val;
  22 }
  23
  24 static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset)
  25 {
  26         tsunami_tig_writeb(value.x[0], offset);
  27 }
  28
  29 static void tsunami_flash_copy_from(
  30         struct map_info *map, void *addr, unsigned long offset, ssize_t len)
  31 {
  32         unsigned char *dest;
  33         dest = addr;
  34         while(len && (offset < MAX_TIG_FLASH_SIZE)) {
  35                 *dest = tsunami_tig_readb(offset);
  36                 offset++;
  37                 dest++;
  38                 len--;
  39         }
  40 }
  41
  42 static void tsunami_flash_copy_to(
  43         struct map_info *map, unsigned long offset,
  44         const void *addr, ssize_t len)
  45 {
  46         const unsigned char *src;
  47         src = addr;
  48         while(len && (offset < MAX_TIG_FLASH_SIZE)) {
  49                 tsunami_tig_writeb(*src, offset);
  50                 offset++;
  51                 src++;
  52                 len--;
  53         }
  54 }
  55
  56 /*
  57  * Deliberately don't provide operations wider than 8 bits.  I don't
  58  * have then and it scares me to think how you could mess up if
  59  * you tried to use them.   Buswidth is correctly so I'm safe.
  60  */
  61 static struct map_info tsunami_flash_map = {
  62         .name = "flash chip on the Tsunami TIG bus",
  63         .size = MAX_TIG_FLASH_SIZE,
  64         .phys = NO_XIP,
  65         .bankwidth = 1,
  66         .read = tsunami_flash_read8,
  67         .copy_from = tsunami_flash_copy_from,
  68         .write = tsunami_flash_write8,
  69         .copy_to = tsunami_flash_copy_to,
  70 };
  71
  72 static struct mtd_info *tsunami_flash_mtd;
  73
  74 static void __exit  cleanup_tsunami_flash(void)
  75 {
  76         struct mtd_info *mtd;
  77         mtd = tsunami_flash_mtd;
  78         if (mtd) {
  79                 mtd_device_unregister(mtd);
  80                 map_destroy(mtd);
  81         }
  82         tsunami_flash_mtd = 0;
  83 }
  84
  85
  86 static int __init init_tsunami_flash(void)
  87 {
  88         static const char *rom_probe_types[] = { "cfi_probe", "jedec_probe", "map_rom", NULL };
  89         char **type;
  90
  91         tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT);
  92
  93         tsunami_flash_mtd = 0;
  94         type = rom_probe_types;
  95         for(; !tsunami_flash_mtd && *type; type++) {
  96                 tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map);
  97         }
  98         if (tsunami_flash_mtd) {
  99                 tsunami_flash_mtd->owner = THIS_MODULE;
 100                 mtd_device_register(tsunami_flash_mtd, NULL, 0);
 101                 return 0;
 102         }
 103         return -ENXIO;
 104 }
 105
 106 module_init(init_tsunami_flash);
 107 module_exit(cleanup_tsunami_flash);