hw/tc58128.c

   1 #include <assert.h>
   2 #include "hw.h"
   3 #include "sh.h"
   4 #include "sysemu.h"
   5
   6 #define CE1  0x0100
   7 #define CE2  0x0200
   8 #define RE   0x0400
   9 #define WE   0x0800
  10 #define ALE  0x1000
  11 #define CLE  0x2000
  12 #define RDY1 0x4000
  13 #define RDY2 0x8000
  14 #define RDY(n) ((n) == 0 ? RDY1 : RDY2)
  15
  16 typedef enum { WAIT, READ1, READ2, READ3 } state_t;
  17
  18 typedef struct {
  19     uint8_t *flash_contents;
  20     state_t state;
  21     uint32_t address;
  22     uint8_t address_cycle;
  23 } tc58128_dev;
  24
  25 static tc58128_dev tc58128_devs[2];
  26
  27 #define FLASH_SIZE (16*1024*1024)
  28
  29 static void init_dev(tc58128_dev * dev, const char *filename)
  30 {
  31     int ret, blocks;
  32
  33     dev->state = WAIT;
  34     dev->flash_contents = qemu_mallocz(FLASH_SIZE);
  35     memset(dev->flash_contents, 0xff, FLASH_SIZE);
  36     if (!dev->flash_contents) {
  37         fprintf(stderr, "could not alloc memory for flash\n");
  38         exit(1);
  39     }
  40     if (filename) {
  41         /* Load flash image skipping the first block */
  42         ret = load_image(filename, dev->flash_contents + 528 * 32);
  43         if (ret < 0) {
  44             fprintf(stderr, "ret=%d\n", ret);
  45             fprintf(stderr, "qemu: could not load flash image %s\n",
  46                     filename);
  47             exit(1);
  48         } else {
  49             /* Build first block with number of blocks */
  50             blocks = (ret + 528 * 32 - 1) / (528 * 32);
  51             dev->flash_contents[0] = blocks & 0xff;
  52             dev->flash_contents[1] = (blocks >> 8) & 0xff;
  53             dev->flash_contents[2] = (blocks >> 16) & 0xff;
  54             dev->flash_contents[3] = (blocks >> 24) & 0xff;
  55             fprintf(stderr, "loaded %d bytes for %s into flash\n", ret,
  56                     filename);
  57         }
  58     }
  59 }
  60
  61 static void handle_command(tc58128_dev * dev, uint8_t command)
  62 {
  63     switch (command) {
  64     case 0xff:
  65         fprintf(stderr, "reset flash device\n");
  66         dev->state = WAIT;
  67         break;
  68     case 0x00:
  69         fprintf(stderr, "read mode 1\n");
  70         dev->state = READ1;
  71         dev->address_cycle = 0;
  72         break;
  73     case 0x01:
  74         fprintf(stderr, "read mode 2\n");
  75         dev->state = READ2;
  76         dev->address_cycle = 0;
  77         break;
  78     case 0x50:
  79         fprintf(stderr, "read mode 3\n");
  80         dev->state = READ3;
  81         dev->address_cycle = 0;
  82         break;
  83     default:
  84         fprintf(stderr, "unknown flash command 0x%02x\n", command);
  85         assert(0);
  86     }
  87 }
  88
  89 static void handle_address(tc58128_dev * dev, uint8_t data)
  90 {
  91     switch (dev->state) {
  92     case READ1:
  93     case READ2:
  94     case READ3:
  95         switch (dev->address_cycle) {
  96         case 0:
  97             dev->address = data;
  98             if (dev->state == READ2)
  99                 dev->address |= 0x100;
 100             else if (dev->state == READ3)
 101                 dev->address |= 0x200;
 102             break;
 103         case 1:
 104             dev->address += data * 528 * 0x100;
 105             break;
 106         case 2:
 107             dev->address += data * 528;
 108             fprintf(stderr, "address pointer in flash: 0x%08x\n",
 109                     dev->address);
 110             break;
 111         default:
 112             /* Invalid data */
 113             assert(0);
 114         }
 115         dev->address_cycle++;
 116         break;
 117     default:
 118         assert(0);
 119     }
 120 }
 121
 122 static uint8_t handle_read(tc58128_dev * dev)
 123 {
 124 #if 0
 125     if (dev->address % 0x100000 == 0)
 126         fprintf(stderr, "reading flash at address 0x%08x\n", dev->address);
 127 #endif
 128     return dev->flash_contents[dev->address++];
 129 }
 130
 131 /* We never mark the device as busy, so interrupts cannot be triggered
 132    XXXXX */
 133
 134 static int tc58128_cb(uint16_t porta, uint16_t portb,
 135                       uint16_t * periph_pdtra, uint16_t * periph_portadir,
 136                       uint16_t * periph_pdtrb, uint16_t * periph_portbdir)
 137 {
 138     int dev;
 139
 140     if ((porta & CE1) == 0)
 141         dev = 0;
 142     else if ((porta & CE2) == 0)
 143         dev = 1;
 144     else
 145         return 0;               /* No device selected */
 146
 147     if ((porta & RE) && (porta & WE)) {
 148         /* Nothing to do, assert ready and return to input state */
 149         *periph_portadir &= 0xff00;
 150         *periph_portadir |= RDY(dev);
 151         *periph_pdtra |= RDY(dev);
 152         return 1;
 153     }
 154
 155     if (porta & CLE) {
 156         /* Command */
 157         assert((porta & WE) == 0);
 158         handle_command(&tc58128_devs[dev], porta & 0x00ff);
 159     } else if (porta & ALE) {
 160         assert((porta & WE) == 0);
 161         handle_address(&tc58128_devs[dev], porta & 0x00ff);
 162     } else if ((porta & RE) == 0) {
 163         *periph_portadir |= 0x00ff;
 164         *periph_pdtra &= 0xff00;
 165         *periph_pdtra |= handle_read(&tc58128_devs[dev]);
 166     } else {
 167         assert(0);
 168     }
 169     return 1;
 170 }
 171
 172 static sh7750_io_device tc58128 = {
 173     RE | WE,                    /* Port A triggers */
 174     0,                          /* Port B triggers */
 175     tc58128_cb                  /* Callback */
 176 };
 177
 178 int tc58128_init(struct SH7750State *s, const char *zone1, const char *zone2)
 179 {
 180     init_dev(&tc58128_devs[0], zone1);
 181     init_dev(&tc58128_devs[1], zone2);
 182     return sh7750_register_io_device(s, &tc58128);
 183 }