diff options
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/libata-core.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 09639e7aaa7..9269fd9b814 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -1538,6 +1538,152 @@ void ata_port_disable(struct ata_port *ap) ap->flags |= ATA_FLAG_PORT_DISABLED; } +/* + * This mode timing computation functionality is ported over from + * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik + */ +/* + * PIO 0-5, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds). + * These were taken from ATA/ATAPI-6 standard, rev 0a, except + * for PIO 5, which is a nonstandard extension and UDMA6, which + * is currently supported only by Maxtor drives. + */ + +static const struct ata_timing ata_timing[] = { + + { XFER_UDMA_6, 0, 0, 0, 0, 0, 0, 0, 15 }, + { XFER_UDMA_5, 0, 0, 0, 0, 0, 0, 0, 20 }, + { XFER_UDMA_4, 0, 0, 0, 0, 0, 0, 0, 30 }, + { XFER_UDMA_3, 0, 0, 0, 0, 0, 0, 0, 45 }, + + { XFER_UDMA_2, 0, 0, 0, 0, 0, 0, 0, 60 }, + { XFER_UDMA_1, 0, 0, 0, 0, 0, 0, 0, 80 }, + { XFER_UDMA_0, 0, 0, 0, 0, 0, 0, 0, 120 }, + +/* { XFER_UDMA_SLOW, 0, 0, 0, 0, 0, 0, 0, 150 }, */ + + { XFER_MW_DMA_2, 25, 0, 0, 0, 70, 25, 120, 0 }, + { XFER_MW_DMA_1, 45, 0, 0, 0, 80, 50, 150, 0 }, + { XFER_MW_DMA_0, 60, 0, 0, 0, 215, 215, 480, 0 }, + + { XFER_SW_DMA_2, 60, 0, 0, 0, 120, 120, 240, 0 }, + { XFER_SW_DMA_1, 90, 0, 0, 0, 240, 240, 480, 0 }, + { XFER_SW_DMA_0, 120, 0, 0, 0, 480, 480, 960, 0 }, + +/* { XFER_PIO_5, 20, 50, 30, 100, 50, 30, 100, 0 }, */ + { XFER_PIO_4, 25, 70, 25, 120, 70, 25, 120, 0 }, + { XFER_PIO_3, 30, 80, 70, 180, 80, 70, 180, 0 }, + + { XFER_PIO_2, 30, 290, 40, 330, 100, 90, 240, 0 }, + { XFER_PIO_1, 50, 290, 93, 383, 125, 100, 383, 0 }, + { XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0 }, + +/* { XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960, 0 }, */ + + { 0xFF } +}; + +#define ENOUGH(v,unit) (((v)-1)/(unit)+1) +#define EZ(v,unit) ((v)?ENOUGH(v,unit):0) + +static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT) +{ + q->setup = EZ(t->setup * 1000, T); + q->act8b = EZ(t->act8b * 1000, T); + q->rec8b = EZ(t->rec8b * 1000, T); + q->cyc8b = EZ(t->cyc8b * 1000, T); + q->active = EZ(t->active * 1000, T); + q->recover = EZ(t->recover * 1000, T); + q->cycle = EZ(t->cycle * 1000, T); + q->udma = EZ(t->udma * 1000, UT); +} + +void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b, + struct ata_timing *m, unsigned int what) +{ + if (what & ATA_TIMING_SETUP ) m->setup = max(a->setup, b->setup); + if (what & ATA_TIMING_ACT8B ) m->act8b = max(a->act8b, b->act8b); + if (what & ATA_TIMING_REC8B ) m->rec8b = max(a->rec8b, b->rec8b); + if (what & ATA_TIMING_CYC8B ) m->cyc8b = max(a->cyc8b, b->cyc8b); + if (what & ATA_TIMING_ACTIVE ) m->active = max(a->active, b->active); + if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover); + if (what & ATA_TIMING_CYCLE ) m->cycle = max(a->cycle, b->cycle); + if (what & ATA_TIMING_UDMA ) m->udma = max(a->udma, b->udma); +} + +static const struct ata_timing* ata_timing_find_mode(unsigned short speed) +{ + const struct ata_timing *t; + + for (t = ata_timing; t->mode != speed; t++) + if (t->mode != 0xFF) + return NULL; + return t; +} + +int ata_timing_compute(struct ata_device *adev, unsigned short speed, + struct ata_timing *t, int T, int UT) +{ + const struct ata_timing *s; + struct ata_timing p; + + /* + * Find the mode. + */ + + if (!(s = ata_timing_find_mode(speed))) + return -EINVAL; + + /* + * If the drive is an EIDE drive, it can tell us it needs extended + * PIO/MW_DMA cycle timing. + */ + + if (adev->id[ATA_ID_FIELD_VALID] & 2) { /* EIDE drive */ + memset(&p, 0, sizeof(p)); + if(speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) { + if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO]; + else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY]; + } else if(speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) { + p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN]; + } + ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B); + } + + /* + * Convert the timing to bus clock counts. + */ + + ata_timing_quantize(s, 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_PIO_4) { + ata_timing_compute(adev, adev->pio_mode, &p, T, UT); + ata_timing_merge(&p, t, t, ATA_TIMING_ALL); + } + + /* + * Lenghten 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; +} + static struct { unsigned int shift; u8 base; @@ -4764,6 +4910,9 @@ EXPORT_SYMBOL_GPL(ata_dev_id_string); EXPORT_SYMBOL_GPL(ata_dev_config); EXPORT_SYMBOL_GPL(ata_scsi_simulate); +EXPORT_SYMBOL_GPL(ata_timing_compute); +EXPORT_SYMBOL_GPL(ata_timing_merge); + #ifdef CONFIG_PCI EXPORT_SYMBOL_GPL(pci_test_config_bits); EXPORT_SYMBOL_GPL(ata_pci_host_stop); |