Commit 04d8f3fd authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Lee Jones
Browse files

backlight: apple_bl: Convert to a platform driver 

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 Apple Backlight 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: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarDaniel Thompson (RISCstar) <danielt@kernel.org>
Link: https://patch.msgid.link/5084777.GXAFRqVoOG@rafael.j.wysocki


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 797cc011

drivers/video/backlight/apple_bl.c

+11 −10
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/pci.h>

#include <linux/acpi.h>

#include <linux/atomic.h>

#include <linux/platform_device.h>

#include <acpi/video.h>



static struct backlight_device *apple_backlight_device;
@@ -134,7 +135,7 @@ static const struct hw_data nvidia_chipset_data = { 
	.set_brightness = nvidia_chipset_set_brightness,

};



static int apple_bl_add(struct acpi_device *dev)

static int apple_bl_probe(struct platform_device *pdev)

{

	struct backlight_properties props;

	struct pci_dev *host;
@@ -193,7 +194,7 @@ static int apple_bl_add(struct acpi_device *dev) 
	return 0;

}



static void apple_bl_remove(struct acpi_device *dev)

static void apple_bl_remove(struct platform_device *pdev)

{

	backlight_device_unregister(apple_backlight_device);
@@ -206,12 +207,12 @@ static const struct acpi_device_id apple_bl_ids[] = { 
	{"", 0},

};



static struct acpi_driver apple_bl_driver = {

	.name = "Apple backlight",

	.ids = apple_bl_ids,

	.ops = {

		.add = apple_bl_add,

static struct platform_driver apple_bl_driver = {

	.probe = apple_bl_probe,

	.remove = apple_bl_remove,

	.driver = {

		.name = "Apple backlight",

		.acpi_match_table = apple_bl_ids,

	},

};
@@ -224,12 +225,12 @@ static int __init apple_bl_init(void) 
	if (acpi_video_get_backlight_type() != acpi_backlight_vendor)

		return -ENODEV;



	return acpi_bus_register_driver(&apple_bl_driver);

	return platform_driver_register(&apple_bl_driver);

}



static void __exit apple_bl_exit(void)

{

	acpi_bus_unregister_driver(&apple_bl_driver);

	platform_driver_unregister(&apple_bl_driver);

}



module_init(apple_bl_init);