1: /*
    2:  * QEMU NVRAM emulation for DS1225Y chip
    3:  * 
    4:  * Copyright (c) 2007 Herv?oussineau
    5:  * 
    6:  * Permission is hereby granted, free of charge, to any person obtaining a copy
    7:  * of this software and associated documentation files (the "Software"), to deal
    8:  * in the Software without restriction, including without limitation the rights
    9:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   10:  * copies of the Software, and to permit persons to whom the Software is
   11:  * furnished to do so, subject to the following conditions:
   12:  *
   13:  * The above copyright notice and this permission notice shall be included in
   14:  * all copies or substantial portions of the Software.
   15:  *
   16:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   17:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   18:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   19:  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   20:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   21:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   22:  * THE SOFTWARE.
   23:  */
   24: 
   25: #include "hw.h"
   26: #include "mips.h"
   27: #include "nvram.h"
   28: 
   29: typedef enum
   30: {
   31:     none = 0,
   32:     readmode,
   33:     writemode,
   34: } nvram_open_mode;
   35: 
   36: struct ds1225y_t
   37: {
   38:     target_phys_addr_t mem_base;
   39:     uint32_t capacity;
   40:     const char *filename;
   41:     QEMUFile *file;
   42:     nvram_open_mode open_mode;
   43: };
   44: 
   45: static int ds1225y_set_to_mode(ds1225y_t *NVRAM, nvram_open_mode mode, const char *filemode)
   46: {
   47:     if (NVRAM->open_mode != mode)
   48:     {
   49:         if (NVRAM->file)
   50:             qemu_fclose(NVRAM->file);
   51:         NVRAM->file = qemu_fopen(NVRAM->filename, filemode);
   52:         NVRAM->open_mode = mode;
   53:     }
   54:     return (NVRAM->file != NULL);
   55: }
   56: 
   57: static uint32_t nvram_readb (void *opaque, target_phys_addr_t addr)
   58: {
   59:     ds1225y_t *NVRAM = opaque;
   60:     int64_t pos;
   61: 
   62:     pos = addr - NVRAM->mem_base;
   63:     if (addr >= NVRAM->capacity)
   64:         addr -= NVRAM->capacity;
   65: 
   66:     if (!ds1225y_set_to_mode(NVRAM, readmode, "rb"))
   67:         return 0;
   68:     qemu_fseek(NVRAM->file, pos, SEEK_SET);
   69:     return (uint32_t)qemu_get_byte(NVRAM->file);
   70: }
   71: 
   72: static void nvram_writeb (void *opaque, target_phys_addr_t addr, uint32_t value)
   73: {
   74:     ds1225y_t *NVRAM = opaque;
   75:     int64_t pos;
   76: 
   77:     pos = addr - NVRAM->mem_base;
   78:     if (ds1225y_set_to_mode(NVRAM, writemode, "wb"))
   79:     {
   80:         qemu_fseek(NVRAM->file, pos, SEEK_SET);
   81:         qemu_put_byte(NVRAM->file, (int)value);
   82:     }
   83: }
   84: 
   85: static CPUReadMemoryFunc *nvram_read[] = {
   86:     &nvram_readb,
   87:     NULL,
   88:     NULL,
   89: };
   90: 
   91: static CPUWriteMemoryFunc *nvram_write[] = {
   92:     &nvram_writeb,
   93:     NULL,
   94:     NULL,
   95: };
   96: 
   97: static CPUWriteMemoryFunc *nvram_none[] = {
   98:     NULL,
   99:     NULL,
  100:     NULL,
  101: };
  102: 
  103: /* Initialisation routine */
  104: ds1225y_t *ds1225y_init(target_phys_addr_t mem_base, const char *filename)
  105: {
  106:     ds1225y_t *s;
  107:     int mem_index1, mem_index2;
  108: 
  109:     s = qemu_mallocz(sizeof(ds1225y_t));
  110:     if (!s)
  111:         return NULL;
  112:     s->mem_base = mem_base;
  113:     s->capacity = 0x2000; /* Fixed for ds1225y chip: 8K */
  114:     s->filename = filename;
  115: 
  116:     /* Read/write memory */
  117:     mem_index1 = cpu_register_io_memory(0, nvram_read, nvram_write, s);
  118:     cpu_register_physical_memory(mem_base, s->capacity, mem_index1);
  119:     /* Read-only memory */
  120:     mem_index2 = cpu_register_io_memory(0, nvram_read, nvram_none, s);
  121:     cpu_register_physical_memory(mem_base + s->capacity, s->capacity, mem_index2);
  122:     return s;
  123: }