[PATCH v2 5/6] ACPI: platform: Add macro for acpi platform driver

[Slawomir Rosek <srosek@google.com>]

Introduce module_acpi_platform_driver() macro to simplify dynamic
enumeration of ACPI device objects on the platform bus by loadable
modules. Move common code from the intel-hid and intel-vbtn drivers
to the ACPI platform core.

Signed-off-by: Slawomir Rosek <srosek@google.com>
---
 drivers/acpi/acpi_platform.c      | 27 +++++++++++++++++++++++++
 drivers/platform/x86/intel/hid.c  | 33 +++----------------------------
 drivers/platform/x86/intel/vbtn.c | 30 +---------------------------
 include/linux/platform_device.h   | 17 ++++++++++++++++
 4 files changed, 48 insertions(+), 59 deletions(-)

diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c
index 48d15dd785f6..adf32ffa6be6 100644
--- a/drivers/acpi/acpi_platform.c
+++ b/drivers/acpi/acpi_platform.c
@@ -190,6 +190,33 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev,
 }
 EXPORT_SYMBOL_GPL(acpi_create_platform_device);
 
+static acpi_status
+__acpi_platform_driver_register_cb(acpi_handle handle, u32 lvl,
+				void *context, void **rv)
+{
+	const struct acpi_device_id *ids = context;
+	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
+
+	if (dev && acpi_match_device_ids(dev, ids) == 0)
+		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL))) {
+			dev_info(&dev->dev,
+				 "created platform device\n");
+		}
+
+	return AE_OK;
+}
+
+int __acpi_platform_driver_register(struct platform_driver *drv,
+				struct module *owner)
+{
+	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
+			    __acpi_platform_driver_register_cb, NULL,
+			    (void *)drv->driver.acpi_match_table, NULL);
+
+	return __platform_driver_register(drv, owner);
+}
+EXPORT_SYMBOL_GPL(__acpi_platform_driver_register);
+
 void __init acpi_platform_init(void)
 {
 	acpi_reconfig_notifier_register(&acpi_platform_notifier);
diff --git a/drivers/platform/x86/intel/hid.c b/drivers/platform/x86/intel/hid.c
index f25a427cccda..37f990686446 100644
--- a/drivers/platform/x86/intel/hid.c
+++ b/drivers/platform/x86/intel/hid.c
@@ -775,34 +775,7 @@ static struct platform_driver intel_hid_pl_driver = {
  *
  * As a workaround until the ACPI core figures out how to handle
  * this corner case, manually ask the ACPI platform device code to
- * claim the ACPI node.
+ * claim the ACPI node by using module_acpi_platform_driver()
+ * instead of the regular module_platform_driver().
  */
-static acpi_status __init
-check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
-{
-	const struct acpi_device_id *ids = context;
-	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
-
-	if (dev && acpi_match_device_ids(dev, ids) == 0)
-		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
-			dev_info(&dev->dev,
-				 "intel-hid: created platform device\n");
-
-	return AE_OK;
-}
-
-static int __init intel_hid_init(void)
-{
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
-			    (void *)intel_hid_ids, NULL);
-
-	return platform_driver_register(&intel_hid_pl_driver);
-}
-module_init(intel_hid_init);
-
-static void __exit intel_hid_exit(void)
-{
-	platform_driver_unregister(&intel_hid_pl_driver);
-}
-module_exit(intel_hid_exit);
+module_acpi_platform_driver(intel_hid_pl_driver);
diff --git a/drivers/platform/x86/intel/vbtn.c b/drivers/platform/x86/intel/vbtn.c
index 232cd12e3c9f..42932479de35 100644
--- a/drivers/platform/x86/intel/vbtn.c
+++ b/drivers/platform/x86/intel/vbtn.c
@@ -390,32 +390,4 @@ static struct platform_driver intel_vbtn_pl_driver = {
 	.remove = intel_vbtn_remove,
 };
 
-static acpi_status __init
-check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
-{
-	const struct acpi_device_id *ids = context;
-	struct acpi_device *dev = acpi_fetch_acpi_dev(handle);
-
-	if (dev && acpi_match_device_ids(dev, ids) == 0)
-		if (!IS_ERR_OR_NULL(acpi_create_platform_device(dev, NULL)))
-			dev_info(&dev->dev,
-				 "intel-vbtn: created platform device\n");
-
-	return AE_OK;
-}
-
-static int __init intel_vbtn_init(void)
-{
-	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
-			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
-			    (void *)intel_vbtn_ids, NULL);
-
-	return platform_driver_register(&intel_vbtn_pl_driver);
-}
-module_init(intel_vbtn_init);
-
-static void __exit intel_vbtn_exit(void)
-{
-	platform_driver_unregister(&intel_vbtn_pl_driver);
-}
-module_exit(intel_vbtn_exit);
+module_acpi_platform_driver(intel_vbtn_pl_driver);
diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h
index 074754c23d33..3b70b054d8a5 100644
--- a/include/linux/platform_device.h
+++ b/include/linux/platform_device.h
@@ -264,6 +264,14 @@ extern int __platform_driver_register(struct platform_driver *,
 					struct module *);
 extern void platform_driver_unregister(struct platform_driver *);
 
+/*
+ * use a macro to avoid include chaining to get THIS_MODULE
+ */
+#define acpi_platform_driver_register(drv) \
+	__acpi_platform_driver_register(drv, THIS_MODULE)
+extern int __acpi_platform_driver_register(struct platform_driver *,
+					struct module *);
+
 /* non-hotpluggable platform devices may use this so that probe() and
  * its support may live in __init sections, conserving runtime memory.
  */
@@ -292,6 +300,15 @@ static inline void platform_set_drvdata(struct platform_device *pdev,
 	module_driver(__platform_driver, platform_driver_register, \
 			platform_driver_unregister)
 
+/* module_acpi_platform_driver() - Helper macro for drivers that don't do
+ * anything special in module init/exit.  This eliminates a lot of
+ * boilerplate.  Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit()
+ */
+#define module_acpi_platform_driver(__platform_driver) \
+	module_driver(__platform_driver, acpi_platform_driver_register, \
+			platform_driver_unregister)
+
 /* builtin_platform_driver() - Helper macro for builtin drivers that
  * don't do anything special in driver init.  This eliminates some
  * boilerplate.  Each driver may only use this macro once, and
-- 
2.51.0.384.g4c02a37b29-goog