+static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
+{
+ struct ata_link *link = dev->link;
+ struct ata_port *ap = link->ap;
+ u32 scontrol;
+ unsigned int err_mask;
+ int rc;
+
+ /*
+ * disallow DIPM for drivers which haven't set
+ * ATA_FLAG_IPM. This is because when DIPM is enabled,
+ * phy ready will be set in the interrupt status on
+ * state changes, which will cause some drivers to
+ * think there are errors - additionally drivers will
+ * need to disable hot plug.
+ */
+ if (!(ap->flags & ATA_FLAG_IPM) || !ata_dev_enabled(dev)) {
+ ap->pm_policy = NOT_AVAILABLE;
+ return -EINVAL;
+ }
+
+ /*
+ * For DIPM, we will only enable it for the
+ * min_power setting.
+ *
+ * Why? Because Disks are too stupid to know that
+ * If the host rejects a request to go to SLUMBER
+ * they should retry at PARTIAL, and instead it
+ * just would give up. So, for medium_power to
+ * work at all, we need to only allow HIPM.
+ */
+ rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
+ if (rc)
+ return rc;
+
+ switch (policy) {
+ case MIN_POWER:
+ /* no restrictions on IPM transitions */
+ scontrol &= ~(0x3 << 8);
+ rc = sata_scr_write(link, SCR_CONTROL, scontrol);
+ if (rc)
+ return rc;
+
+ /* enable DIPM */
+ if (dev->flags & ATA_DFLAG_DIPM)
+ err_mask = ata_dev_set_feature(dev,
+ SETFEATURES_SATA_ENABLE, SATA_DIPM);
+ break;
+ case MEDIUM_POWER:
+ /* allow IPM to PARTIAL */
+ scontrol &= ~(0x1 << 8);
+ scontrol |= (0x2 << 8);
+ rc = sata_scr_write(link, SCR_CONTROL, scontrol);
+ if (rc)
+ return rc;
+
+ /*
+ * we don't have to disable DIPM since IPM flags
+ * disallow transitions to SLUMBER, which effectively
+ * disable DIPM if it does not support PARTIAL
+ */
+ break;
+ case NOT_AVAILABLE:
+ case MAX_PERFORMANCE:
+ /* disable all IPM transitions */
+ scontrol |= (0x3 << 8);
+ rc = sata_scr_write(link, SCR_CONTROL, scontrol);
+ if (rc)
+ return rc;
+
+ /*
+ * we don't have to disable DIPM since IPM flags
+ * disallow all transitions which effectively
+ * disable DIPM anyway.
+ */
+ break;
+ }
+
+ /* FIXME: handle SET FEATURES failure */
+ (void) err_mask;
+
+ return 0;
+}
+
+/**
+ * ata_dev_enable_pm - enable SATA interface power management
+ * @dev: device to enable power management
+ * @policy: the link power management policy
+ *
+ * Enable SATA Interface power management. This will enable
+ * Device Interface Power Management (DIPM) for min_power
+ * policy, and then call driver specific callbacks for
+ * enabling Host Initiated Power management.
+ *
+ * Locking: Caller.
+ * Returns: -EINVAL if IPM is not supported, 0 otherwise.
+ */
+void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy)
+{
+ int rc = 0;
+ struct ata_port *ap = dev->link->ap;
+
+ /* set HIPM first, then DIPM */
+ if (ap->ops->enable_pm)
+ rc = ap->ops->enable_pm(ap, policy);
+ if (rc)
+ goto enable_pm_out;
+ rc = ata_dev_set_dipm(dev, policy);
+
+enable_pm_out:
+ if (rc)
+ ap->pm_policy = MAX_PERFORMANCE;
+ else
+ ap->pm_policy = policy;
+ return /* rc */; /* hopefully we can use 'rc' eventually */
+}
+
+#ifdef CONFIG_PM
+/**
+ * ata_dev_disable_pm - disable SATA interface power management
+ * @dev: device to disable power management
+ *
+ * Disable SATA Interface power management. This will disable
+ * Device Interface Power Management (DIPM) without changing
+ * policy, call driver specific callbacks for disabling Host
+ * Initiated Power management.
+ *
+ * Locking: Caller.
+ * Returns: void
+ */
+static void ata_dev_disable_pm(struct ata_device *dev)
+{
+ struct ata_port *ap = dev->link->ap;
+
+ ata_dev_set_dipm(dev, MAX_PERFORMANCE);
+ if (ap->ops->disable_pm)
+ ap->ops->disable_pm(ap);
+}
+#endif /* CONFIG_PM */
+
+void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
+{
+ ap->pm_policy = policy;
+ ap->link.eh_info.action |= ATA_EHI_LPM;
+ ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
+ ata_port_schedule_eh(ap);
+}
+
+#ifdef CONFIG_PM
+static void ata_lpm_enable(struct ata_host *host)
+{
+ struct ata_link *link;
+ struct ata_port *ap;
+ struct ata_device *dev;
+ int i;
+
+ for (i = 0; i < host->n_ports; i++) {
+ ap = host->ports[i];
+ ata_port_for_each_link(link, ap) {
+ ata_link_for_each_dev(dev, link)
+ ata_dev_disable_pm(dev);
+ }
+ }
+}
+
+static void ata_lpm_disable(struct ata_host *host)
+{
+ int i;
+
+ for (i = 0; i < host->n_ports; i++) {
+ struct ata_port *ap = host->ports[i];
+ ata_lpm_schedule(ap, ap->pm_policy);
+ }
+}
+#endif /* CONFIG_PM */
+
+