hw/tc58128.c

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