ACPI / bind: Rework struct acpi_bus_type

Replace the .find_device function pointer in struct acpi_bus_type
with a new one, .find_companion, that is supposed to point to a
function returning struct acpi_device pointer (instead of an int)
and takes one argument (instead of two).  This way the role of
this callback is more clear and the implementation of it can
be more straightforward.

Update all of the users of struct acpi_bus_type (PCI, PNP/ACPI and
USB) to reflect the structure change.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Lan Tianyu <tianyu.lan@intel.com> # for USB/ACPI

drivers/acpi/glue.c

@@ -37,7 +37,7 @@ int register_acpi_bus_type(struct acpi_bus_type *type)
 {
 	if (acpi_disabled)
 		return -ENODEV;
-	if (type && type->match && type->find_device) {
+	if (type && type->match && type->find_companion) {
 		down_write(&bus_type_sem);
 		list_add_tail(&type->list, &bus_type_list);
 		up_write(&bus_type_sem);
@@ -302,17 +302,19 @@ EXPORT_SYMBOL_GPL(acpi_unbind_one);
 static int acpi_platform_notify(struct device *dev)
 {
 	struct acpi_bus_type *type = acpi_get_bus_type(dev);
-	acpi_handle handle;
 	int ret;
 
 	ret = acpi_bind_one(dev, NULL);
 	if (ret && type) {
-		ret = type->find_device(dev, &handle);
-		if (ret) {
+		struct acpi_device *adev;
+
+		adev = type->find_companion(dev);
+		if (!adev) {
 			DBG("Unable to get handle for %s\n", dev_name(dev));
+			ret = -ENODEV;
 			goto out;
 		}
-		ret = acpi_bind_one(dev, handle);
+		ret = acpi_bind_one(dev, adev->handle);
 		if (ret)
 			goto out;
 	}

drivers/pci/pci-acpi.c

@@ -303,10 +303,9 @@ void acpi_pci_remove_bus(struct pci_bus *bus)
 }
 
 /* ACPI bus type */
-static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
+static struct acpi_device *acpi_pci_find_companion(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct acpi_device *adev;
 	bool check_children;
 	u64 addr;
 
@@ -319,13 +318,8 @@ static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 			|| pci_dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
 	/* Please ref to ACPI spec for the syntax of _ADR */
 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
-	adev = acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
+	return acpi_find_child_device(ACPI_COMPANION(dev->parent), addr,
 				      check_children);
-	if (adev) {
-		*handle = adev->handle;
-		return 0;
-	}
-	return -ENODEV;
 }
 
 static void pci_acpi_setup(struct device *dev)
@@ -365,7 +359,7 @@ static bool pci_acpi_bus_match(struct device *dev)
 static struct acpi_bus_type acpi_pci_bus = {
 	.name = "PCI",
 	.match = pci_acpi_bus_match,
-	.find_device = acpi_pci_find_device,
+	.find_companion = acpi_pci_find_companion,
 	.setup = pci_acpi_setup,
 	.cleanup = pci_acpi_cleanup,
 };

drivers/pnp/pnpacpi/core.c

@@ -328,20 +328,15 @@ static int __init acpi_pnp_match(struct device *dev, void *_pnp)
 	    && compare_pnp_id(pnp->id, acpi_device_hid(acpi));
 }
 
-static int __init acpi_pnp_find_device(struct device *dev, acpi_handle * handle)
+static struct acpi_device * __init acpi_pnp_find_companion(struct device *dev)
 {
-	struct device *adev;
-	struct acpi_device *acpi;
-
-	adev = bus_find_device(&acpi_bus_type, NULL,
-			       to_pnp_dev(dev), acpi_pnp_match);
-	if (!adev)
-		return -ENODEV;
+	dev = bus_find_device(&acpi_bus_type, NULL, to_pnp_dev(dev),
+			      acpi_pnp_match);
+	if (!dev)
+		return NULL;
 
-	acpi = to_acpi_device(adev);
-	*handle = acpi->handle;
-	put_device(adev);
-	return 0;
+	put_device(dev);
+	return to_acpi_device(dev);
 }
 
 /* complete initialization of a PNPACPI device includes having
@@ -355,7 +350,7 @@ static bool acpi_pnp_bus_match(struct device *dev)
 static struct acpi_bus_type __initdata acpi_pnp_bus = {
 	.name	     = "PNP",
 	.match	     = acpi_pnp_bus_match,
-	.find_device = acpi_pnp_find_device,
+	.find_companion = acpi_pnp_find_companion,
 };
 
 int pnpacpi_disabled __initdata;

drivers/usb/core/usb-acpi.c

@@ -126,7 +126,7 @@ out:
 	return ret;
 }
 
-static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
+static struct acpi_device *usb_acpi_find_companion(struct device *dev)
 {
 	struct usb_device *udev;
 	acpi_handle *parent_handle;
@@ -168,16 +168,15 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
 				break;
 			}
 
-			return -ENODEV;
+			return NULL;
 		}
 
 		/* root hub's parent is the usb hcd. */
-		parent_handle = ACPI_HANDLE(dev->parent);
-		*handle = acpi_get_child(parent_handle, udev->portnum);
-		if (!*handle)
-			return -ENODEV;
-		return 0;
+		return acpi_find_child_device(ACPI_COMPANION(dev->parent),
+					      udev->portnum, false);
 	} else if (is_usb_port(dev)) {
+		struct acpi_device *adev = NULL;
+
 		sscanf(dev_name(dev), "port%d", &port_num);
 		/* Get the struct usb_device point of port's hub */
 		udev = to_usb_device(dev->parent->parent);
@@ -193,26 +192,27 @@ static int usb_acpi_find_device(struct device *dev, acpi_handle *handle)
 
 			raw_port_num = usb_hcd_find_raw_port_number(hcd,
 				port_num);
-			*handle = acpi_get_child(ACPI_HANDLE(&udev->dev),
-				raw_port_num);
-			if (!*handle)
-				return -ENODEV;
+			adev = acpi_find_child_device(ACPI_COMPANION(&udev->dev),
+						      raw_port_num, false);
+			if (!adev)
+				return NULL;
 		} else {
 			parent_handle =
 				usb_get_hub_port_acpi_handle(udev->parent,
 				udev->portnum);
 			if (!parent_handle)
-				return -ENODEV;
+				return NULL;
 
-			*handle = acpi_get_child(parent_handle,	port_num);
-			if (!*handle)
-				return -ENODEV;
+			acpi_bus_get_device(parent_handle, &adev);
+			adev = acpi_find_child_device(adev, port_num, false);
+			if (!adev)
+				return NULL;
 		}
-		usb_acpi_check_port_connect_type(udev, *handle, port_num);
-	} else
-		return -ENODEV;
+		usb_acpi_check_port_connect_type(udev, adev->handle, port_num);
+		return adev;
+	}
 
-	return 0;
+	return NULL;
 }
 
 static bool usb_acpi_bus_match(struct device *dev)
@@ -223,7 +223,7 @@ static bool usb_acpi_bus_match(struct device *dev)
 static struct acpi_bus_type usb_acpi_bus = {
 	.name = "USB",
 	.match = usb_acpi_bus_match,
-	.find_device = usb_acpi_find_device,
+	.find_companion = usb_acpi_find_companion,
 };
 
 int usb_acpi_register(void)

include/acpi/acpi_bus.h

@@ -412,7 +412,7 @@ struct acpi_bus_type {
 	struct list_head list;
 	const char *name;
 	bool (*match)(struct device *dev);
-	int (*find_device) (struct device *, acpi_handle *);
+	struct acpi_device * (*find_companion)(struct device *);
 	void (*setup)(struct device *);
 	void (*cleanup)(struct device *);
 };