Commit 71f0a267 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Greg Kroah-Hartman
Browse files

hpet: Convert ACPI driver to a platform one 

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 HPET 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>
Link: https://patch.msgid.link/3611505.QJadu78ljV@rafael.j.wysocki


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b1c7f7aa

drivers/char/hpet.c

+10 −8
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/io.h>

#include <linux/acpi.h>

#include <linux/hpet.h>

#include <linux/platform_device.h>

#include <asm/current.h>

#include <asm/irq.h>

#include <asm/div64.h>
@@ -971,8 +972,9 @@ static acpi_status hpet_resources(struct acpi_resource *res, void *data) 
	return AE_OK;

}



static int hpet_acpi_add(struct acpi_device *device)

static int hpet_acpi_probe(struct platform_device *pdev)

{

	struct acpi_device *device = ACPI_COMPANION(&pdev->dev);

	acpi_status result;

	struct hpet_data data;
@@ -1000,11 +1002,11 @@ static const struct acpi_device_id hpet_device_ids[] = { 
	{"", 0},

};



static struct acpi_driver hpet_acpi_driver = {

	.name = "hpet",

	.ids = hpet_device_ids,

	.ops = {

		.add = hpet_acpi_add,

static struct platform_driver hpet_acpi_driver = {

	.probe = hpet_acpi_probe,

	.driver = {

		.name = "hpet_acpi",

		.acpi_match_table = hpet_device_ids,

	},

};
@@ -1020,7 +1022,7 @@ static int __init hpet_init(void) 


	sysctl_header = register_sysctl("dev/hpet", hpet_table);



	result = acpi_bus_register_driver(&hpet_acpi_driver);

	result = platform_driver_register(&hpet_acpi_driver);

	if (result < 0) {

		unregister_sysctl_table(sysctl_header);

		misc_deregister(&hpet_misc);