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>

3 files changed, 26 insertions, 19 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 69e29f409d4c..0e9c0d38b85c 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/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:
diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index c0a39417ebe4..9f7bcfdf18ef 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/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)
diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h
index 957391306cbf..bb7de413d06d 100644
--- a/drivers/acpi/internal.h
+++ b/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