ACPI: video: Convert the driver to a platform one

While binding drivers directly to struct acpi_device objects allows
basic functionality to be provided, at least in the majority of cases,
there are some problems with it, related to general consistency, sysfs
layout, power management operation ordering, and code cleanliness.

Overall, it is better to bind drivers to platform devices than to their
ACPI companions, so convert the ACPI video 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.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://patch.msgid.link/1957556.tdWV9SEqCh@rafael.j.wysocki

Author: rafaeljw

drivers/acpi/acpi_video.c

@@ -21,6 +21,7 @@
 #include <linux/sort.h>
 #include <linux/pci.h>
 #include <linux/pci_ids.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/dmi.h>
 #include <linux/suspend.h>
@@ -76,8 +77,8 @@ static int register_count;
 static DEFINE_MUTEX(register_count_mutex);
 static DEFINE_MUTEX(video_list_lock);
 static LIST_HEAD(video_bus_head);
-static int acpi_video_bus_add(struct acpi_device *device);
-static void acpi_video_bus_remove(struct acpi_device *device);
+static int acpi_video_bus_probe(struct platform_device *pdev);
+static void acpi_video_bus_remove(struct platform_device *pdev);
 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data);
 
 /*
@@ -98,14 +99,13 @@ static const struct acpi_device_id video_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 
-static struct acpi_driver acpi_video_bus = {
-	.name = "video",
-	.class = ACPI_VIDEO_CLASS,
-	.ids = video_device_ids,
-	.ops = {
-		.add = acpi_video_bus_add,
-		.remove = acpi_video_bus_remove,
-		},
+static struct platform_driver acpi_video_bus = {
+	.probe = acpi_video_bus_probe,
+	.remove = acpi_video_bus_remove,
+	.driver = {
+		.name = "acpi-video",
+		.acpi_match_table = video_device_ids,
+	},
 };
 
 struct acpi_video_bus_flags {
@@ -1888,7 +1888,8 @@ static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
 		device->flags.notify = 1;
 }
 
-static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
+static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video,
+					     struct platform_device *pdev)
 {
 	struct input_dev *input;
 	struct acpi_video_device *dev;
@@ -1911,7 +1912,7 @@ static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
 	input->phys = video->phys;
 	input->id.bustype = BUS_HOST;
 	input->id.product = 0x06;
-	input->dev.parent = &video->device->dev;
+	input->dev.parent = &pdev->dev;
 	input->evbit[0] = BIT(EV_KEY);
 	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
 	set_bit(KEY_VIDEO_NEXT, input->keybit);
@@ -1983,8 +1984,9 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
 
 static int instance;
 
-static int acpi_video_bus_add(struct acpi_device *device)
+static int acpi_video_bus_probe(struct platform_device *pdev)
 {
+	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
 	struct acpi_video_bus *video;
 	bool auto_detect;
 	int error;
@@ -2021,6 +2023,8 @@ static int acpi_video_bus_add(struct acpi_device *device)
 		instance++;
 	}
 
+	platform_set_drvdata(pdev, video);
+
 	video->device = device;
 	strscpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
 	strscpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
@@ -2068,7 +2072,7 @@ static int acpi_video_bus_add(struct acpi_device *device)
 	    !auto_detect)
 		acpi_video_bus_register_backlight(video);
 
-	error = acpi_video_bus_add_notify_handler(video);
+	error = acpi_video_bus_add_notify_handler(video, pdev);
 	if (error)
 		goto err_del;
 
@@ -2096,15 +2100,10 @@ static int acpi_video_bus_add(struct acpi_device *device)
 	return error;
 }
 
-static void acpi_video_bus_remove(struct acpi_device *device)
+static void acpi_video_bus_remove(struct platform_device *pdev)
 {
-	struct acpi_video_bus *video = NULL;
-
-
-	if (!device || !acpi_driver_data(device))
-		return;
-
-	video = acpi_driver_data(device);
+	struct acpi_video_bus *video = platform_get_drvdata(pdev);
+	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
 
 	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
 				       acpi_video_bus_notify);
@@ -2167,7 +2166,7 @@ int acpi_video_register(void)
 
 	dmi_check_system(video_dmi_table);
 
-	ret = acpi_bus_register_driver(&acpi_video_bus);
+	ret = platform_driver_register(&acpi_video_bus);
 	if (ret)
 		goto leave;
 
@@ -2187,7 +2186,7 @@ void acpi_video_unregister(void)
 {
 	mutex_lock(&register_count_mutex);
 	if (register_count) {
-		acpi_bus_unregister_driver(&acpi_video_bus);
+		platform_driver_unregister(&acpi_video_bus);
 		register_count = 0;
 		may_report_brightness_keys = false;
 	}