[PATCH 12/15] sas_ata: Implement sata phy control

Darrick J. Wong
2006-11-17T21:01:56Z

This patch requires "libsas: Add a sysfs knob to enable/disable a phy"
to be applied. It hooks the SControl write function to provide basic
SATA phy control for phy enable/disable and speed limits. Power
management is still broken, though it is unclear that libata actually
uses those SControl bits anyway.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---

drivers/scsi/libsas/sas_ata.c | 42 ++++++++++++++++++++++++++++++++++-
drivers/scsi/libsas/sas_scsi_host.c | 1 +
2 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index e2650fa..e897140 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -270,6 +270,46 @@ static void sas_ata_tf_read(struct ata_p
memcpy(tf, &dev->sata_dev.tf, sizeof (*tf));
}

+static void sas_ata_scontrol_write(struct domain_device *dev, u32 val)
+{
+ u32 tmp = dev->sata_dev.scontrol;
+ struct sas_phy *phy = dev->port->phy;
+
+ val &= 0x0FF; /* only set max spd and dev ctrl */
+ val |= 0x300; /* disallow host pm */
+ val |= tmp & 0xFFFFF000; /* preserve upper bits */
+
+ /* disable phy */
+ if ((val & 0x4) && !(tmp & 0x4))
+ sas_phy_enable(phy, 0);
+
+ /* enable phy */
+ if (!(val & 0x4) && (tmp & 0x4))
+ sas_phy_enable(phy, 1);
+
+ /* reset phy */
+ if ((val & 0x1) && !(tmp & 0x1))
+ sas_phy_reset(phy, 0);
+
+ /* speed limit */
+ if ((val & 0xF0) != (tmp & 0xF0)) {
+ struct sas_phy_linkrates rates = {0};
+
+ switch ((val & 0xF0) >> 4) {
+ case 0:
+ case 2:
+ rates.maximum_linkrate = SAS_LINK_RATE_3_0_GBPS;
+ break;
+ case 1:
+ rates.maximum_linkrate = SAS_LINK_RATE_1_5_GBPS;
+ break;
+ }
+ sas_set_phy_speed(phy, &rates);
+ }
+
+ dev->sata_dev.scontrol = val;
+}
+
static void sas_ata_scr_write(struct ata_port *ap, unsigned int sc_reg_in,
u32 val)
{
@@ -281,7 +321,7 @@ static void sas_ata_scr_write(struct ata
dev->sata_dev.sstatus = val;
break;
case SCR_CONTROL:
- dev->sata_dev.scontrol = val;
+ sas_ata_scontrol_write(dev, val);
break;
case SCR_ERROR:
dev->sata_dev.serror = val;
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 25639b5..59409be 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -938,3 +938,4 @@ EXPORT_SYMBOL_GPL(sas_ioctl);
EXPORT_SYMBOL_GPL(sas_task_abort);
EXPORT_SYMBOL_GPL(sas_phy_reset);
EXPORT_SYMBOL_GPL(sas_phy_enable);
+EXPORT_SYMBOL_GPL(sas_set_phy_speed);