LXR linux/drivers/mtd/maps/tsunami

   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)
  18static 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
  25static 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
  30static 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
  43static 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 */
  62static 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
  73static struct mtd_info *tsunami_flash_mtd;
  74
  75static 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
  86static const char * const rom_probe_types[] = {
  87        "cfi_probe", "jedec_probe", "map_rom", NULL };
  88
  89static 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
 108module_init(init_tsunami_flash);
 109module_exit(cleanup_tsunami_flash);
 110