diff options
Diffstat (limited to 'hw/tc58128.c')
| -rw-r--r-- | hw/tc58128.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/hw/tc58128.c b/hw/tc58128.c new file mode 100644 index 0000000000..a8b26f7e8c --- /dev/null +++ b/hw/tc58128.c @@ -0,0 +1,181 @@ +#include <assert.h> +#include "vl.h" + +#define CE1 0x0100 +#define CE2 0x0200 +#define RE 0x0400 +#define WE 0x0800 +#define ALE 0x1000 +#define CLE 0x2000 +#define RDY1 0x4000 +#define RDY2 0x8000 +#define RDY(n) ((n) == 0 ? RDY1 : RDY2) + +typedef enum { WAIT, READ1, READ2, READ3 } state_t; + +typedef struct { + uint8_t *flash_contents; + state_t state; + uint32_t address; + uint8_t address_cycle; +} tc58128_dev; + +static tc58128_dev tc58128_devs[2]; + +#define FLASH_SIZE (16*1024*1024) + +void init_dev(tc58128_dev * dev, char *filename) +{ + int ret, blocks; + + dev->state = WAIT; + dev->flash_contents = qemu_mallocz(FLASH_SIZE); + memset(dev->flash_contents, 0xff, FLASH_SIZE); + if (!dev->flash_contents) { + fprintf(stderr, "could not alloc memory for flash\n"); + exit(1); + } + if (filename) { + /* Load flash image skipping the first block */ + ret = load_image(filename, dev->flash_contents + 528 * 32); + if (ret < 0) { + fprintf(stderr, "ret=%d\n", ret); + fprintf(stderr, "qemu: could not load flash image %s\n", + filename); + exit(1); + } else { + /* Build first block with number of blocks */ + blocks = (ret + 528 * 32 - 1) / (528 * 32); + dev->flash_contents[0] = blocks & 0xff; + dev->flash_contents[1] = (blocks >> 8) & 0xff; + dev->flash_contents[2] = (blocks >> 16) & 0xff; + dev->flash_contents[3] = (blocks >> 24) & 0xff; + fprintf(stderr, "loaded %d bytes for %s into flash\n", ret, + filename); + } + } +} + +void handle_command(tc58128_dev * dev, uint8_t command) +{ + switch (command) { + case 0xff: + fprintf(stderr, "reset flash device\n"); + dev->state = WAIT; + break; + case 0x00: + fprintf(stderr, "read mode 1\n"); + dev->state = READ1; + dev->address_cycle = 0; + break; + case 0x01: + fprintf(stderr, "read mode 2\n"); + dev->state = READ2; + dev->address_cycle = 0; + break; + case 0x50: + fprintf(stderr, "read mode 3\n"); + dev->state = READ3; + dev->address_cycle = 0; + break; + default: + fprintf(stderr, "unknown flash command 0x%02x\n", command); + assert(0); + } +} + +void handle_address(tc58128_dev * dev, uint8_t data) +{ + switch (dev->state) { + case READ1: + case READ2: + case READ3: + switch (dev->address_cycle) { + case 0: + dev->address = data; + if (dev->state == READ2) + dev->address |= 0x100; + else if (dev->state == READ3) + dev->address |= 0x200; + break; + case 1: + dev->address += data * 528 * 0x100; + break; + case 2: + dev->address += data * 528; + fprintf(stderr, "address pointer in flash: 0x%08x\n", + dev->address); + break; + default: + /* Invalid data */ + assert(0); + } + dev->address_cycle++; + break; + default: + assert(0); + } +} + +uint8_t handle_read(tc58128_dev * dev) +{ +#if 0 + if (dev->address % 0x100000 == 0) + fprintf(stderr, "reading flash at address 0x%08x\n", dev->address); +#endif + return dev->flash_contents[dev->address++]; +} + +/* We never mark the device as busy, so interrupts cannot be triggered + XXXXX */ + +int tc58128_cb(uint16_t porta, uint16_t portb, + uint16_t * periph_pdtra, uint16_t * periph_portadir, + uint16_t * periph_pdtrb, uint16_t * periph_portbdir) +{ + int dev; + + if ((porta & CE1) == 0) + dev = 0; + else if ((porta & CE2) == 0) + dev = 1; + else + return 0; /* No device selected */ + + if ((porta & RE) && (porta & WE)) { + /* Nothing to do, assert ready and return to input state */ + *periph_portadir &= 0xff00; + *periph_portadir |= RDY(dev); + *periph_pdtra |= RDY(dev); + return 1; + } + + if (porta & CLE) { + /* Command */ + assert((porta & WE) == 0); + handle_command(&tc58128_devs[dev], porta & 0x00ff); + } else if (porta & ALE) { + assert((porta & WE) == 0); + handle_address(&tc58128_devs[dev], porta & 0x00ff); + } else if ((porta & RE) == 0) { + *periph_portadir |= 0x00ff; + *periph_pdtra &= 0xff00; + *periph_pdtra |= handle_read(&tc58128_devs[dev]); + } else { + assert(0); + } + return 1; +} + +static sh7750_io_device tc58128 = { + RE | WE, /* Port A triggers */ + 0, /* Port B triggers */ + tc58128_cb /* Callback */ +}; + +int tc58128_init(struct SH7750State *s, char *zone1, char *zone2) +{ + init_dev(&tc58128_devs[0], zone1); + init_dev(&tc58128_devs[1], zone2); + return sh7750_register_io_device(s, &tc58128); +} |