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authorTejun Heo <htejun@gmail.com>2007-12-18 16:33:03 +0900
committerJeff Garzik <jeff@garzik.org>2008-01-23 05:24:12 -0500
commit7c77fa4d51b1480bcec2e898c94d6912fe063c16 (patch)
treed7d18fb22c8df2425878d02f4b415c06efa56457 /drivers/ata/libata-acpi.c
parent9cde9ed151e170f2e2a530f7ec0032dfbe9f443b (diff)
downloadop-kernel-dev-7c77fa4d51b1480bcec2e898c94d6912fe063c16.zip
op-kernel-dev-7c77fa4d51b1480bcec2e898c94d6912fe063c16.tar.gz
libata: separate out ata_acpi_gtm_xfermask() from pacpi_discover_modes()
Finding out matching transfer mode from ACPI GTM values is useful for other purposes too. Separate out the function and timing tables from pata_acpi::pacpi_discover_modes(). Other than checking shared-configuration bit after doing ata_acpi_gtm() in pacpi_discover_modes() which should be safe, this patch doesn't introduce any behavior change. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/libata-acpi.c')
-rw-r--r--drivers/ata/libata-acpi.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index ebc4dfc..d6697ba 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -441,6 +441,84 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf)
return rc;
}
+/* Welcome to ACPI, bring a bucket */
+const unsigned int ata_acpi_pio_cycle[7] = {
+ 600, 383, 240, 180, 120, 100, 80
+};
+EXPORT_SYMBOL_GPL(ata_acpi_pio_cycle);
+
+const unsigned int ata_acpi_mwdma_cycle[5] = {
+ 480, 150, 120, 100, 80
+};
+EXPORT_SYMBOL_GPL(ata_acpi_mwdma_cycle);
+
+const unsigned int ata_acpi_udma_cycle[7] = {
+ 120, 80, 60, 45, 30, 20, 15
+};
+EXPORT_SYMBOL_GPL(ata_acpi_udma_cycle);
+
+/**
+ * ata_acpi_gtm_xfermode - determine xfermode from GTM parameter
+ * @dev: target device
+ * @gtm: GTM parameter to use
+ *
+ * Determine xfermask for @dev from @gtm.
+ *
+ * LOCKING:
+ * None.
+ *
+ * RETURNS:
+ * Determined xfermask.
+ */
+unsigned long ata_acpi_gtm_xfermask(struct ata_device *dev,
+ const struct ata_acpi_gtm *gtm)
+{
+ int unit, i;
+ u32 t;
+ unsigned long mask = (0x7f << ATA_SHIFT_UDMA) | (0x7 << ATA_SHIFT_MWDMA) | (0x1F << ATA_SHIFT_PIO);
+
+ /* we always use the 0 slot for crap hardware */
+ unit = dev->devno;
+ if (!(gtm->flags & 0x10))
+ unit = 0;
+
+ /* start by scanning for PIO modes */
+ for (i = 0; i < 7; i++) {
+ t = gtm->drive[unit].pio;
+ if (t <= ata_acpi_pio_cycle[i]) {
+ mask |= (2 << (ATA_SHIFT_PIO + i)) - 1;
+ break;
+ }
+ }
+
+ /* See if we have MWDMA or UDMA data. We don't bother with
+ * MWDMA if UDMA is available as this means the BIOS set UDMA
+ * and our error changedown if it works is UDMA to PIO anyway.
+ */
+ if (gtm->flags & (1 << (2 * unit))) {
+ /* MWDMA */
+ for (i = 0; i < 5; i++) {
+ t = gtm->drive[unit].dma;
+ if (t <= ata_acpi_mwdma_cycle[i]) {
+ mask |= (2 << (ATA_SHIFT_MWDMA + i)) - 1;
+ break;
+ }
+ }
+ } else {
+ /* UDMA */
+ for (i = 0; i < 7; i++) {
+ t = gtm->drive[unit].dma;
+ if (t <= ata_acpi_udma_cycle[i]) {
+ mask |= (2 << (ATA_SHIFT_UDMA + i)) - 1;
+ break;
+ }
+ }
+ }
+
+ return mask;
+}
+EXPORT_SYMBOL_GPL(ata_acpi_gtm_xfermask);
+
/**
* ata_acpi_cbl_80wire - Check for 80 wire cable
* @ap: Port to check
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