[PATCH v1 2/2] platform/x86: wireless-hotkey: 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 airplane mode button for AMD, HP and
Xiaomi laptops driver from an 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/wireless-hotkey.c | 44 ++++++++++++++------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/platform/x86/wireless-hotkey.c b/drivers/platform/x86/wireless-hotkey.c
index a0ae757a277e..f680d8ff8e87 100644
--- a/drivers/platform/x86/wireless-hotkey.c
+++ b/drivers/platform/x86/wireless-hotkey.c
@@ -35,16 +35,17 @@ static const struct acpi_device_id wl_ids[] = {
 	{"", 0},
 };
 
-static int wireless_input_setup(struct acpi_device *device)
+static int wireless_input_setup(struct device *dev)
 {
-	struct wl_button *button = acpi_driver_data(device);
+	struct wl_button *button = dev_get_drvdata(dev);
 	int err;
 
 	button->input_dev = input_allocate_device();
 	if (!button->input_dev)
 		return -ENOMEM;
 
-	snprintf(button->phys, sizeof(button->phys), "%s/input0", acpi_device_hid(device));
+	snprintf(button->phys, sizeof(button->phys), "%s/input0",
+		 acpi_device_hid(ACPI_COMPANION(dev)));
 
 	button->input_dev->name = "Wireless hotkeys";
 	button->input_dev->phys = button->phys;
@@ -63,9 +64,9 @@ static int wireless_input_setup(struct acpi_device *device)
 	return err;
 }
 
-static void wireless_input_destroy(struct acpi_device *device)
+static void wireless_input_destroy(struct device *dev)
 {
-	struct wl_button *button = acpi_driver_data(device);
+	struct wl_button *button = dev_get_drvdata(dev);
 
 	input_unregister_device(button->input_dev);
 	kfree(button);
@@ -86,7 +87,7 @@ static void wl_notify(acpi_handle handle, u32 event, void *data)
 	input_sync(button->input_dev);
 }
 
-static int wl_add(struct acpi_device *device)
+static int wl_probe(struct platform_device *pdev)
 {
 	struct wl_button *button;
 	int err;
@@ -95,37 +96,38 @@ static int wl_add(struct acpi_device *device)
 	if (!button)
 		return -ENOMEM;
 
-	device->driver_data = button;
+	platform_set_drvdata(pdev, button);
 
-	err = wireless_input_setup(device);
+	err = wireless_input_setup(&pdev->dev);
 	if (err) {
 		pr_err("Failed to setup wireless hotkeys\n");
 		kfree(button);
 		return err;
 	}
-	err = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
-					      wl_notify, button);
+	err = acpi_dev_install_notify_handler(ACPI_COMPANION(&pdev->dev),
+					      ACPI_DEVICE_NOTIFY, wl_notify, button);
 	if (err) {
 		pr_err("Failed to install ACPI notify handler\n");
-		wireless_input_destroy(device);
+		wireless_input_destroy(&pdev->dev);
 	}
 
 	return err;
 }
 
-static void wl_remove(struct acpi_device *device)
+static void wl_remove(struct platform_device *pdev)
 {
-	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY, wl_notify);
-	wireless_input_destroy(device);
+	acpi_dev_remove_notify_handler(ACPI_COMPANION(&pdev->dev),
+				       ACPI_DEVICE_NOTIFY, wl_notify);
+	wireless_input_destroy(&pdev->dev);
 }
 
-static struct acpi_driver wl_driver = {
-	.name	= "wireless-hotkey",
-	.ids	= wl_ids,
-	.ops	= {
-		.add	= wl_add,
-		.remove	= wl_remove,
+static struct platform_driver wl_driver = {
+	.probe = wl_probe,
+	.remove = wl_remove,
+	.driver = {
+		.name = "wireless-hotkey",
+		.acpi_match_table = wl_ids,
 	},
 };
 
-module_acpi_driver(wl_driver);
+module_platform_driver(wl_driver);
-- 
2.51.0