ACPI / platform / LPSS: Enable async suspend/resume of LPSS devices

To seed up suspend and resume of devices included into Intel SoCs
handled by the ACPI LPSS driver during system suspend, make
acpi_lpss_create_device() call device_enable_async_suspend() for
every device created by it.

This requires acpi_create_platform_device() to be modified to return
a pointer to struct platform_device instead of an int.  As a result,
acpi_create_platform_device() cannot be pointed to by the .attach
pointer in platform_handler directly any more, so a simple wrapper
around it is necessary for this purpose.  That, in turn, allows the
second unused argument of acpi_create_platform_device() to be
dropped, which is an improvement.
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpi_lpss.c

@@ -267,12 +267,14 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 	struct lpss_private_data *pdata;
 	struct resource_list_entry *rentry;
 	struct list_head resource_list;
+	struct platform_device *pdev;
 	int ret;
 
 	dev_desc = (struct lpss_device_desc *)id->driver_data;
-	if (!dev_desc)
-		return acpi_create_platform_device(adev, id);
-
+	if (!dev_desc) {
+		pdev = acpi_create_platform_device(adev);
+		return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1;
+	}
 	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return -ENOMEM;
@@ -322,10 +324,13 @@ static int acpi_lpss_create_device(struct acpi_device *adev,
 		dev_desc->setup(pdata);
 
 	adev->driver_data = pdata;
-	ret = acpi_create_platform_device(adev, id);
-	if (ret > 0)
-		return ret;
+	pdev = acpi_create_platform_device(adev);
+	if (!IS_ERR_OR_NULL(pdev)) {
+		device_enable_async_suspend(&pdev->dev);
+		return 1;
+	}
 
+	ret = PTR_ERR(pdev);
 	adev->driver_data = NULL;
 
  err_out:

drivers/acpi/acpi_platform.c

@@ -47,7 +47,6 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
 /**
  * acpi_create_platform_device - Create platform device for ACPI device node
  * @adev: ACPI device node to create a platform device for.
- * @id: ACPI device ID used to match @adev.
  *
  * Check if the given @adev can be represented as a platform device and, if
  * that's the case, create and register a platform device, populate its common
@@ -55,8 +54,7 @@ static const struct acpi_device_id acpi_platform_device_ids[] = {
  *
  * Name of the platform device will be the same as @adev's.
  */
-int acpi_create_platform_device(struct acpi_device *adev,
-				const struct acpi_device_id *id)
+struct platform_device *acpi_create_platform_device(struct acpi_device *adev)
 {
 	struct platform_device *pdev = NULL;
 	struct acpi_device *acpi_parent;
@@ -68,19 +66,19 @@ int acpi_create_platform_device(struct acpi_device *adev,
 
 	/* If the ACPI node already has a physical device attached, skip it. */
 	if (adev->physical_node_count)
-		return 0;
+		return NULL;
 
 	INIT_LIST_HEAD(&resource_list);
 	count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
 	if (count < 0) {
-		return 0;
+		return NULL;
 	} else if (count > 0) {
 		resources = kmalloc(count * sizeof(struct resource),
 				    GFP_KERNEL);
 		if (!resources) {
 			dev_err(&adev->dev, "No memory for resources\n");
 			acpi_dev_free_resource_list(&resource_list);
-			return -ENOMEM;
+			return ERR_PTR(-ENOMEM);
 		}
 		count = 0;
 		list_for_each_entry(rentry, &resource_list, node)
@@ -117,22 +115,27 @@ int acpi_create_platform_device(struct acpi_device *adev,
 	pdevinfo.num_res = count;
 	pdevinfo.acpi_node.companion = adev;
 	pdev = platform_device_register_full(&pdevinfo);
-	if (IS_ERR(pdev)) {
+	if (IS_ERR(pdev))
 		dev_err(&adev->dev, "platform device creation failed: %ld\n",
 			PTR_ERR(pdev));
-		pdev = NULL;
-	} else {
+	else
 		dev_dbg(&adev->dev, "created platform device %s\n",
 			dev_name(&pdev->dev));
-	}
 
 	kfree(resources);
+	return pdev;
+}
+
+static int acpi_platform_attach(struct acpi_device *adev,
+				const struct acpi_device_id *id)
+{
+	acpi_create_platform_device(adev);
 	return 1;
 }
 
 static struct acpi_scan_handler platform_handler = {
 	.ids = acpi_platform_device_ids,
-	.attach = acpi_create_platform_device,
+	.attach = acpi_platform_attach,
 };
 
 void __init acpi_platform_init(void)

drivers/acpi/internal.h

@@ -180,8 +180,7 @@ static inline void suspend_nvs_restore(void) {}
   -------------------------------------------------------------------------- */
 struct platform_device;
 
-int acpi_create_platform_device(struct acpi_device *adev,
-				const struct acpi_device_id *id);
+struct platform_device *acpi_create_platform_device(struct acpi_device *adev);
 
 /*--------------------------------------------------------------------------
 					Video