fdc: Code cleanup in fdctrl_write_data()

Factor out a few common lines of code, reformat, improve comments.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 1432214378-31891-6-git-send-email-kwolf@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
This commit is contained in:
Kevin Wolf 2015-05-21 15:19:35 +02:00 committed by John Snow
parent 5b0a25e8d2
commit d275b33d76

View file

@ -2000,14 +2000,16 @@ static void fdctrl_handle_relative_seek_out(FDCtrl *fdctrl, int direction)
/* /*
* Handlers for the execution phase of each command * Handlers for the execution phase of each command
*/ */
static const struct { typedef struct FDCtrlCommand {
uint8_t value; uint8_t value;
uint8_t mask; uint8_t mask;
const char* name; const char* name;
int parameters; int parameters;
void (*handler)(FDCtrl *fdctrl, int direction); void (*handler)(FDCtrl *fdctrl, int direction);
int direction; int direction;
} handlers[] = { } FDCtrlCommand;
static const FDCtrlCommand handlers[] = {
{ FD_CMD_READ, 0x1f, "READ", 8, fdctrl_start_transfer, FD_DIR_READ }, { FD_CMD_READ, 0x1f, "READ", 8, fdctrl_start_transfer, FD_DIR_READ },
{ FD_CMD_WRITE, 0x3f, "WRITE", 8, fdctrl_start_transfer, FD_DIR_WRITE }, { FD_CMD_WRITE, 0x3f, "WRITE", 8, fdctrl_start_transfer, FD_DIR_WRITE },
{ FD_CMD_SEEK, 0xff, "SEEK", 2, fdctrl_handle_seek }, { FD_CMD_SEEK, 0xff, "SEEK", 2, fdctrl_handle_seek },
@ -2044,9 +2046,19 @@ static const struct {
/* Associate command to an index in the 'handlers' array */ /* Associate command to an index in the 'handlers' array */
static uint8_t command_to_handler[256]; static uint8_t command_to_handler[256];
static const FDCtrlCommand *get_command(uint8_t cmd)
{
int idx;
idx = command_to_handler[cmd];
FLOPPY_DPRINTF("%s command\n", handlers[idx].name);
return &handlers[idx];
}
static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value) static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
{ {
FDrive *cur_drv; FDrive *cur_drv;
const FDCtrlCommand *cmd;
uint32_t pos; uint32_t pos;
/* Reset mode */ /* Reset mode */
@ -2060,15 +2072,22 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
} }
fdctrl->dsr &= ~FD_DSR_PWRDOWN; fdctrl->dsr &= ~FD_DSR_PWRDOWN;
FLOPPY_DPRINTF("%s: %02x\n", __func__, value);
/* If data_len spans multiple sectors, the current position in the FIFO
* wraps around while fdctrl->data_pos is the real position in the whole
* request. */
pos = fdctrl->data_pos++;
pos %= FD_SECTOR_LEN;
fdctrl->fifo[pos] = value;
switch (fdctrl->phase) { switch (fdctrl->phase) {
case FD_PHASE_EXECUTION: case FD_PHASE_EXECUTION:
/* For DMA requests, RQM should be cleared during execution phase, so /* For DMA requests, RQM should be cleared during execution phase, so
* we would have errored out above. */ * we would have errored out above. */
assert(fdctrl->msr & FD_MSR_NONDMA); assert(fdctrl->msr & FD_MSR_NONDMA);
/* FIFO data write */ /* FIFO data write */
pos = fdctrl->data_pos++;
pos %= FD_SECTOR_LEN;
fdctrl->fifo[pos] = value;
if (pos == FD_SECTOR_LEN - 1 || if (pos == FD_SECTOR_LEN - 1 ||
fdctrl->data_pos == fdctrl->data_len) { fdctrl->data_pos == fdctrl->data_len) {
cur_drv = get_cur_drv(fdctrl); cur_drv = get_cur_drv(fdctrl);
@ -2084,41 +2103,37 @@ static void fdctrl_write_data(FDCtrl *fdctrl, uint32_t value)
break; break;
} }
} }
/* Switch from transfer mode to status mode
* then from status mode to command mode /* Switch to result phase when done with the transfer */
*/ if (fdctrl->data_pos == fdctrl->data_len) {
if (fdctrl->data_pos == fdctrl->data_len)
fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00); fdctrl_stop_transfer(fdctrl, 0x00, 0x00, 0x00);
}
break; break;
case FD_PHASE_COMMAND: case FD_PHASE_COMMAND:
assert(!(fdctrl->msr & FD_MSR_NONDMA)); assert(!(fdctrl->msr & FD_MSR_NONDMA));
assert(fdctrl->data_pos < FD_SECTOR_LEN);
if (fdctrl->data_pos == 0) { if (pos == 0) {
/* Command */ /* The first byte specifies the command. Now we start reading
pos = command_to_handler[value & 0xff]; * as many parameters as this command requires. */
FLOPPY_DPRINTF("%s command\n", handlers[pos].name); cmd = get_command(value);
fdctrl->data_len = handlers[pos].parameters + 1; fdctrl->data_len = cmd->parameters + 1;
fdctrl->msr |= FD_MSR_CMDBUSY; fdctrl->msr |= FD_MSR_CMDBUSY;
} }
FLOPPY_DPRINTF("%s: %02x\n", __func__, value);
pos = fdctrl->data_pos++;
pos %= FD_SECTOR_LEN;
fdctrl->fifo[pos] = value;
if (fdctrl->data_pos == fdctrl->data_len) { if (fdctrl->data_pos == fdctrl->data_len) {
/* We now have all parameters /* We have all parameters now, execute the command */
* and will be able to treat the command
*/
fdctrl->phase = FD_PHASE_EXECUTION; fdctrl->phase = FD_PHASE_EXECUTION;
if (fdctrl->data_state & FD_STATE_FORMAT) { if (fdctrl->data_state & FD_STATE_FORMAT) {
fdctrl_format_sector(fdctrl); fdctrl_format_sector(fdctrl);
break; break;
} }
pos = command_to_handler[fdctrl->fifo[0] & 0xff]; cmd = get_command(fdctrl->fifo[0]);
FLOPPY_DPRINTF("treat %s command\n", handlers[pos].name); FLOPPY_DPRINTF("Calling handler for '%s'\n", cmd->name);
(*handlers[pos].handler)(fdctrl, handlers[pos].direction); cmd->handler(fdctrl, cmd->direction);
} }
break; break;