[PATCH v1 2/4] platform/x86: asus-laptop: Convert ACPI driver to a platform one

[Rafael J. Wysocki]

From: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>

In all cases in which a struct acpi_driver is used for binding a driver
to an ACPI device object, a corresponding platform device is created by
the ACPI core and that device is regarded as a proper representation of
underlying hardware.  Accordingly, a struct platform_driver should be
used by driver code to bind to that device.  There are multiple reasons
why drivers should not bind directly to ACPI device objects [1].

Overall, it is better to bind drivers to platform devices than to their
ACPI companions, so convert the Asus laptop ACPI driver to a platform
one.

While this is not expected to alter functionality, it changes sysfs
layout and so it will be visible to user space.

Link: https://lore.kernel.org/all/2396510.ElGaqSPkdT@rafael.j.wysocki/ [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
 drivers/platform/x86/asus-laptop.c | 35 +++++++++++++++---------------
 1 file changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/platform/x86/asus-laptop.c b/drivers/platform/x86/asus-laptop.c
index c927665dfa96..dbbb6292cd11 100644
--- a/drivers/platform/x86/asus-laptop.c
+++ b/drivers/platform/x86/asus-laptop.c
@@ -1824,8 +1824,9 @@ static void asus_dmi_check(void)
 
 static bool asus_device_present;
 
-static int asus_acpi_add(struct acpi_device *device)
+static int asus_acpi_probe(struct platform_device *pdev)
 {
+	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
 	struct asus_laptop *asus;
 	int result;
 
@@ -1837,7 +1838,6 @@ static int asus_acpi_add(struct acpi_device *device)
 	asus->handle = device->handle;
 	strscpy(acpi_device_name(device), ASUS_LAPTOP_DEVICE_NAME);
 	strscpy(acpi_device_class(device), ASUS_LAPTOP_CLASS);
-	device->driver_data = asus;
 	asus->device = device;
 
 	asus_dmi_check();
@@ -1846,6 +1846,8 @@ static int asus_acpi_add(struct acpi_device *device)
 	if (result)
 		goto fail_platform;
 
+	platform_set_drvdata(pdev, asus);
+
 	/*
 	 * Need platform type detection first, then the platform
 	 * device.  It is used as a parent for the sub-devices below.
@@ -1907,11 +1909,12 @@ static int asus_acpi_add(struct acpi_device *device)
 	return result;
 }
 
-static void asus_acpi_remove(struct acpi_device *device)
+static void asus_acpi_remove(struct platform_device *pdev)
 {
-	struct asus_laptop *asus = acpi_driver_data(device);
+	struct asus_laptop *asus = platform_get_drvdata(pdev);
 
-	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY, asus_acpi_notify);
+	acpi_dev_remove_notify_handler(asus->device, ACPI_DEVICE_NOTIFY,
+				       asus_acpi_notify);
 	asus_backlight_exit(asus);
 	asus_rfkill_exit(asus);
 	asus_led_exit(asus);
@@ -1930,15 +1933,13 @@ static const struct acpi_device_id asus_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, asus_device_ids);
 
-static struct acpi_driver asus_acpi_driver = {
-	.name = ASUS_LAPTOP_NAME,
-	.class = ASUS_LAPTOP_CLASS,
-	.ids = asus_device_ids,
-	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
-	.ops = {
-		.add = asus_acpi_add,
-		.remove = asus_acpi_remove,
-		},
+static struct platform_driver asus_acpi_driver = {
+	.probe = asus_acpi_probe,
+	.remove = asus_acpi_remove,
+	.driver = {
+		.name = ASUS_LAPTOP_NAME,
+		.acpi_match_table = asus_device_ids,
+	},
 };
 
 static int __init asus_laptop_init(void)
@@ -1949,7 +1950,7 @@ static int __init asus_laptop_init(void)
 	if (result < 0)
 		return result;
 
-	result = acpi_bus_register_driver(&asus_acpi_driver);
+	result = platform_driver_register(&asus_acpi_driver);
 	if (result < 0)
 		goto fail_acpi_driver;
 	if (!asus_device_present) {
@@ -1959,7 +1960,7 @@ static int __init asus_laptop_init(void)
 	return 0;
 
 fail_no_device:
-	acpi_bus_unregister_driver(&asus_acpi_driver);
+	platform_driver_unregister(&asus_acpi_driver);
 fail_acpi_driver:
 	platform_driver_unregister(&platform_driver);
 	return result;
@@ -1967,7 +1968,7 @@ static int __init asus_laptop_init(void)
 
 static void __exit asus_laptop_exit(void)
 {
-	acpi_bus_unregister_driver(&asus_acpi_driver);
+	platform_driver_unregister(&asus_acpi_driver);
 	platform_driver_unregister(&platform_driver);
 }
 
-- 
2.51.0