int ide_timing_compute(ide_drive_t *drive, u8 speed,
struct ide_timing *t, int T, int UT)
{
u16 *id = drive->id;
struct ide_timing *s, p;
s = ide_timing_find_mode(speed);
if (s == NULL)
return -EINVAL;
*t = *s;
if (id[ATA_ID_FIELD_VALID] & 2) {
memset(&p, 0, sizeof(p));
if (speed <= XFER_PIO_2)
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
else if ((speed <= XFER_PIO_4) ||
(speed == XFER_PIO_5 && !ata_id_is_cfa(id)))
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];
else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
p.cycle = id[ATA_ID_EIDE_DMA_MIN];
ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B);
}
ide_timing_quantize(t, t, T, UT);
if (speed >= XFER_SW_DMA_0) {
u8 pio = ide_get_best_pio_mode(drive, 255, 5);
ide_timing_compute(drive, XFER_PIO_0 + pio, &p, T, UT);
ide_timing_merge(&p, t, t, IDE_TIMING_ALL);
}
if (t->act8b + t->rec8b < t->cyc8b) {
t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
t->rec8b = t->cyc8b - t->act8b;
}
if (t->active + t->recover < t->cycle) {
t->active += (t->cycle - (t->active + t->recover)) / 2;
t->recover = t->cycle - t->active;
}
return 0;
}
int ide_timing_compute(ide_drive_t *drive, u8 speed,
struct ide_timing *t, int T, int UT)
{
u16 *id = drive->id;
struct ide_timing *s, p;
/*
* Find the mode.
*/
s = ide_timing_find_mode(speed);
if (s == NULL)
return -EINVAL;
/*
* Copy the timing from the table.
*/
*t = *s;
/*
* If the drive is an EIDE drive, it can tell us it needs extended
* PIO/MWDMA cycle timing.
*/
if (id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */
memset(&p, 0, sizeof(p));
if (speed <= XFER_PIO_2)
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
else if (speed <= XFER_PIO_5)
p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];
else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
p.cycle = id[ATA_ID_EIDE_DMA_MIN];
ide_timing_merge(&p, t, t, IDE_TIMING_CYCLE | IDE_TIMING_CYC8B);
}
/*
* Convert the timing to bus clock counts.
*/
ide_timing_quantize(t, t, T, UT);
/*
* Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
* S.M.A.R.T and some other commands. We have to ensure that the
* DMA cycle timing is slower/equal than the fastest PIO timing.
*/
if (speed >= XFER_SW_DMA_0) {
u8 pio = ide_get_best_pio_mode(drive, 255, 5);
ide_timing_compute(drive, XFER_PIO_0 + pio, &p, T, UT);
ide_timing_merge(&p, t, t, IDE_TIMING_ALL);
}
/*
* Lengthen active & recovery time so that cycle time is correct.
*/
if (t->act8b + t->rec8b < t->cyc8b) {
t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
t->rec8b = t->cyc8b - t->act8b;
}
if (t->active + t->recover < t->cycle) {
t->active += (t->cycle - (t->active + t->recover)) / 2;
t->recover = t->cycle - t->active;
}
return 0;
}
