From a0f79b929acaba10d4780acd2543eff20bf4b5b0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Dec 2007 16:33:05 +0900 Subject: libata: implement ata_timing_cycle2mode() and use it in libata-acpi and pata_acpi libata-acpi is using separate timing tables for transfer modes although libata-core has the complete ata_timing table. Implement ata_timing_cycle2mode() to look for matching mode given transfer type and cycle duration and use it in libata-acpi and pata_acpi to replace private timing tables. Signed-off-by: Tejun Heo Cc: Alan Cox Signed-off-by: Jeff Garzik --- drivers/ata/libata-core.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) (limited to 'drivers/ata/libata-core.c') diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 62c4b328b0b..f01c1734b1d 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -2902,6 +2902,57 @@ int ata_timing_compute(struct ata_device *adev, unsigned short speed, return 0; } +/** + * ata_timing_cycle2mode - find xfer mode for the specified cycle duration + * @xfer_shift: ATA_SHIFT_* value for transfer type to examine. + * @cycle: cycle duration in ns + * + * Return matching xfer mode for @cycle. The returned mode is of + * the transfer type specified by @xfer_shift. If @cycle is too + * slow for @xfer_shift, 0xff is returned. If @cycle is faster + * than the fastest known mode, the fasted mode is returned. + * + * LOCKING: + * None. + * + * RETURNS: + * Matching xfer_mode, 0xff if no match found. + */ +u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle) +{ + u8 base_mode = 0xff, last_mode = 0xff; + const struct ata_xfer_ent *ent; + const struct ata_timing *t; + + for (ent = ata_xfer_tbl; ent->shift >= 0; ent++) + if (ent->shift == xfer_shift) + base_mode = ent->base; + + for (t = ata_timing_find_mode(base_mode); + t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) { + unsigned short this_cycle; + + switch (xfer_shift) { + case ATA_SHIFT_PIO: + case ATA_SHIFT_MWDMA: + this_cycle = t->cycle; + break; + case ATA_SHIFT_UDMA: + this_cycle = t->udma; + break; + default: + return 0xff; + } + + if (cycle > this_cycle) + break; + + last_mode = t->mode; + } + + return last_mode; +} + /** * ata_down_xfermask_limit - adjust dev xfer masks downward * @dev: Device to adjust xfer masks @@ -7630,6 +7681,7 @@ EXPORT_SYMBOL_GPL(ata_pio_need_iordy); EXPORT_SYMBOL_GPL(ata_timing_find_mode); EXPORT_SYMBOL_GPL(ata_timing_compute); EXPORT_SYMBOL_GPL(ata_timing_merge); +EXPORT_SYMBOL_GPL(ata_timing_cycle2mode); #ifdef CONFIG_PCI EXPORT_SYMBOL_GPL(pci_test_config_bits); -- cgit v1.2.3-70-g09d2