From b35d275feae04e753e06488c974cb086a1c78742 Mon Sep 17 00:00:00 2001
From: Matthew Garrett <mjg@redhat.com>
Date: Fri, 3 Jul 2009 00:55:31 +0100
Subject: [PATCH 2/5] Add support for binding the Linux device tree to the ACPI device
 tree for SATA devices.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
 drivers/ata/libata-acpi.c |  118 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 118 insertions(+), 0 deletions(-)

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index ac176da..2d12a2c 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -56,6 +56,31 @@ static void ata_acpi_clear_gtf(struct ata_device *dev)
 	dev->gtf_cache = NULL;
 }
 
+static acpi_handle ap_acpi_handle(struct ata_port *ap)
+{
+	if (ap->flags & ATA_FLAG_ACPI_SATA)
+		return NULL;
+	return DEVICE_ACPI_HANDLE(&ap->scsi_host->shost_gendev);
+}
+
+static acpi_handle dev_acpi_handle(struct ata_device *dev)
+{
+	acpi_integer adr;
+	struct ata_port *ap = dev->link->ap;
+
+	if (dev->sdev)
+		return DEVICE_ACPI_HANDLE(&dev->sdev->sdev_gendev);
+
+	if (ap->flags & ATA_FLAG_ACPI_SATA) {
+		if (!sata_pmp_attached(ap))
+			adr = SATA_ADR(ap->port_no, NO_PORT_MULT);
+		else
+			adr = SATA_ADR(ap->port_no, dev->link->pmp);
+		return acpi_get_child(DEVICE_ACPI_HANDLE(ap->host->dev), adr);
+	} else
+		return acpi_get_child(ap_acpi_handle(ap), dev->devno);
+}
+
 /**
  * ata_acpi_associate_sata_port - associate SATA port with ACPI objects
  * @ap: target SATA port
@@ -1026,3 +1051,96 @@ void ata_acpi_on_disable(struct ata_device *dev)
 {
 	ata_acpi_clear_gtf(dev);
 }
+
+static int is_pci_ata(struct device *dev)
+{
+	struct pci_dev *pdev;
+
+	if (!is_pci_dev(dev))
+		return 0;
+
+	pdev = to_pci_dev(dev);
+
+	if ((pdev->class >> 8) != PCI_CLASS_STORAGE_SATA &&
+	    (pdev->class >> 8) != PCI_CLASS_STORAGE_IDE)
+		return 0;
+
+	return 1;
+}
+
+static int ata_acpi_bind_host(struct device *dev, int host, acpi_handle *handle)
+{
+	struct Scsi_Host *shost = dev_to_shost(dev);
+	struct ata_port *ap = ata_shost_to_port(shost);
+
+	if (ap->flags & ATA_FLAG_ACPI_SATA)
+		return -ENODEV;
+
+	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), ap->port_no);
+
+	if (!*handle)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int ata_acpi_bind_device(struct device *dev, int channel, int id,
+				acpi_handle *handle)
+{
+	struct device *host = dev->parent->parent;
+	struct Scsi_Host *shost = dev_to_shost(host);
+	struct ata_port *ap = ata_shost_to_port(shost);
+	struct ata_device *ata_dev;
+
+	if (ap->flags & ATA_FLAG_ACPI_SATA)
+		ata_dev = &ap->link.device[channel];
+	else
+		ata_dev = &ap->link.device[id];
+
+	*handle = dev_acpi_handle(ata_dev);
+
+	if (!*handle)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int ata_acpi_find_device(struct device *dev, acpi_handle *handle)
+{
+	unsigned int host, channel, id, lun;
+
+	if (sscanf(dev_name(dev), "host%u", &host) == 1) {
+		if (!is_pci_ata(dev->parent))
+			return -ENODEV;
+
+		return ata_acpi_bind_host(dev, host, handle);
+	} else if (sscanf(dev_name(dev), "%d:%d:%d:%d",
+			&host, &channel, &id, &lun) == 4) {
+		if (!is_pci_ata(dev->parent->parent->parent))
+			return -ENODEV;
+
+		return ata_acpi_bind_device(dev, channel, id, handle);
+	} else
+		return -ENODEV;
+}
+
+static int ata_acpi_find_dummy(struct device *dev, acpi_handle *handle)
+{
+	return -ENODEV;
+}
+
+static struct acpi_bus_type ata_acpi_bus = {
+	.bus = &scsi_bus_type,
+	.find_bridge = ata_acpi_find_dummy,
+	.find_device = ata_acpi_find_device,
+};
+
+int scsi_platform_register(void)
+{
+	return register_acpi_bus_type(&ata_acpi_bus);
+}
+
+void scsi_platform_unregister(void)
+{
+	unregister_acpi_bus_type(&ata_acpi_bus);
+}
-- 
1.6.2.5