drivers/mtd/maps/tsunami_flash.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * tsunami_flash.c
   4  *
   5  * flash chip on alpha ds10...
   6  */
   7 #include <asm/io.h>
   8 #include <asm/core_tsunami.h>
   9 #include <linux/init.h>
  10 #include <linux/mtd/map.h>
  11 #include <linux/mtd/mtd.h>
  12
  13 #define FLASH_ENABLE_PORT 0x00C00001
  14 #define FLASH_ENABLE_BYTE 0x01
  15 #define FLASH_DISABLE_BYTE 0x00
  16
  17 #define MAX_TIG_FLASH_SIZE (12*1024*1024)
  18 static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset)
  19 {
  20         map_word val;
  21         val.x[0] = tsunami_tig_readb(offset);
  22         return val;
  23 }
  24
  25 static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset)
  26 {
  27         tsunami_tig_writeb(value.x[0], offset);
  28 }
  29
  30 static void tsunami_flash_copy_from(
  31         struct map_info *map, void *addr, unsigned long offset, ssize_t len)
  32 {
  33         unsigned char *dest;
  34         dest = addr;
  35         while(len && (offset < MAX_TIG_FLASH_SIZE)) {
  36                 *dest = tsunami_tig_readb(offset);
  37                 offset++;
  38                 dest++;
  39                 len--;
  40         }
  41 }
  42
  43 static void tsunami_flash_copy_to(
  44         struct map_info *map, unsigned long offset,
  45         const void *addr, ssize_t len)
  46 {
  47         const unsigned char *src;
  48         src = addr;
  49         while(len && (offset < MAX_TIG_FLASH_SIZE)) {
  50                 tsunami_tig_writeb(*src, offset);
  51                 offset++;
  52                 src++;
  53                 len--;
  54         }
  55 }
  56
  57 /*
  58  * Deliberately don't provide operations wider than 8 bits.  I don't
  59  * have then and it scares me to think how you could mess up if
  60  * you tried to use them.   Buswidth is correctly so I'm safe.
  61  */
  62 static struct map_info tsunami_flash_map = {
  63         .name = "flash chip on the Tsunami TIG bus",
  64         .size = MAX_TIG_FLASH_SIZE,
  65         .phys = NO_XIP,
  66         .bankwidth = 1,
  67         .read = tsunami_flash_read8,
  68         .copy_from = tsunami_flash_copy_from,
  69         .write = tsunami_flash_write8,
  70         .copy_to = tsunami_flash_copy_to,
  71 };
  72
  73 static struct mtd_info *tsunami_flash_mtd;
  74
  75 static void __exit  cleanup_tsunami_flash(void)
  76 {
  77         struct mtd_info *mtd;
  78         mtd = tsunami_flash_mtd;
  79         if (mtd) {
  80                 mtd_device_unregister(mtd);
  81                 map_destroy(mtd);
  82         }
  83         tsunami_flash_mtd = 0;
  84 }
  85
  86 static const char * const rom_probe_types[] = {
  87         "cfi_probe", "jedec_probe", "map_rom", NULL };
  88
  89 static int __init init_tsunami_flash(void)
  90 {
  91         const char * const *type;
  92
  93         tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT);
  94
  95         tsunami_flash_mtd = 0;
  96         type = rom_probe_types;
  97         for(; !tsunami_flash_mtd && *type; type++) {
  98                 tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map);
  99         }
 100         if (tsunami_flash_mtd) {
 101                 tsunami_flash_mtd->owner = THIS_MODULE;
 102                 mtd_device_register(tsunami_flash_mtd, NULL, 0);
 103                 return 0;
 104         }
 105         return -ENXIO;
 106 }
 107
 108 module_init(init_tsunami_flash);
 109 module_exit(cleanup_tsunami_flash);