libata-acpi: implement _GTM/_STM support

Implement _GTM/_STM support.  acpi_gtm is added to ata_port which
stores _GTM parameters over suspend/resume cycle.  A new hook
ata_acpi_on_suspend() is responsible for storing _GTM parameters
during suspend.  _STM is executed in ata_acpi_on_resume().  With this
change, invoking _GTF is safe on IDE hierarchy and acpi_sata check
before _GTF is removed.

ata_acpi_gtm() and ata_acpi_stm() implementation is taken from Alan
Cox's pata_acpi implementation.  ata_acpi_gtm() is fixed such that the
result parameter is not shifted by sizeof(union acpi_object).

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index bee7cbc4c97c..ba17fc5f2e99 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -99,10 +99,12 @@ extern struct ata_port *ata_port_alloc(struct ata_host *host);
 /* libata-acpi.c */
 #ifdef CONFIG_ATA_ACPI
 extern void ata_acpi_associate(struct ata_host *host);
+extern int ata_acpi_on_suspend(struct ata_port *ap);
 extern void ata_acpi_on_resume(struct ata_port *ap);
 extern int ata_acpi_on_devcfg(struct ata_device *adev);
 #else
 static inline void ata_acpi_associate(struct ata_host *host) { }
+static inline int ata_acpi_on_suspend(struct ata_port *ap) { return 0; }
 static inline void ata_acpi_on_resume(struct ata_port *ap) { }
 static inline int ata_acpi_on_devcfg(struct ata_device *adev) { return 0; }
 #endif