dock: introduce .uevent for devices in dock, eg libata

dock's uevent reported itself, not ata. It might be difficult to find an
ata device just according to a dock. This patch introduces docking ops
for each device in a dock. when docking, dock driver can send device
specific uevent. This should help dock station too (not just bay)

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 97727be..c012307 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -209,6 +209,46 @@
 	ata_acpi_handle_hotplug(ap, NULL, event);
 }
 
+static void ata_acpi_uevent(struct ata_port *ap, struct ata_device *dev,
+	u32 event)
+{
+	struct kobject *kobj = NULL;
+	char event_string[20];
+	char *envp[] = { event_string, NULL };
+
+	if (dev) {
+		if (dev->sdev)
+			kobj = &dev->sdev->sdev_gendev.kobj;
+	} else
+		kobj = &ap->dev->kobj;
+
+	if (kobj) {
+		snprintf(event_string, 20, "BAY_EVENT=%d", event);
+		kobject_uevent_env(kobj, KOBJ_CHANGE, envp);
+	}
+}
+
+static void ata_acpi_ap_uevent(acpi_handle handle, u32 event, void *data)
+{
+	ata_acpi_uevent(data, NULL, event);
+}
+
+static void ata_acpi_dev_uevent(acpi_handle handle, u32 event, void *data)
+{
+	struct ata_device *dev = data;
+	ata_acpi_uevent(dev->link->ap, dev, event);
+}
+
+static struct acpi_dock_ops ata_acpi_dev_dock_ops = {
+	.handler = ata_acpi_dev_notify_dock,
+	.uevent = ata_acpi_dev_uevent,
+};
+
+static struct acpi_dock_ops ata_acpi_ap_dock_ops = {
+	.handler = ata_acpi_ap_notify_dock,
+	.uevent = ata_acpi_ap_uevent,
+};
+
 /**
  * ata_acpi_associate - associate ATA host with ACPI objects
  * @host: target ATA host
@@ -244,7 +284,7 @@
 		if (ap->acpi_handle) {
 			/* we might be on a docking station */
 			register_hotplug_dock_device(ap->acpi_handle,
-					     ata_acpi_ap_notify_dock, ap);
+					     &ata_acpi_ap_dock_ops, ap);
 		}
 
 		for (j = 0; j < ata_link_max_devices(&ap->link); j++) {
@@ -253,7 +293,7 @@
 			if (dev->acpi_handle) {
 				/* we might be on a docking station */
 				register_hotplug_dock_device(dev->acpi_handle,
-					     ata_acpi_dev_notify_dock, dev);
+					     &ata_acpi_dev_dock_ops, dev);
 			}
 		}
 	}