platform/x86: topstar-laptop: 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 Topstar Laptop ACPI Extras 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/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/10834824.nUPlyArG6x@rafael.j.wysocki
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/topstar-laptop.c b/drivers/platform/x86/topstar-laptop.c
index 695ec1d25bcd0bd3f5e3cc4613f6523b4e81e316..e09d7f8ce45f971c66406c2047a9ace669742110 100644 (file)
--- a/drivers/platform/x86/topstar-laptop.c
+++ b/drivers/platform/x86/topstar-laptop.c
@@ -285,8 +285,9 @@ static const struct dmi_system_id topstar_dmi_ids[] = {
        {}
 };
 
-static int topstar_acpi_add(struct acpi_device *device)
+static int topstar_acpi_probe(struct platform_device *pdev)
 {
+       struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
        struct topstar_laptop *topstar;
        int err;
 
@@ -296,9 +297,10 @@ static int topstar_acpi_add(struct acpi_device *device)
        if (!topstar)
                return -ENOMEM;
 
+       platform_set_drvdata(pdev, topstar);
+
        strscpy(acpi_device_name(device), "Topstar TPSACPI");
        strscpy(acpi_device_class(device), TOPSTAR_LAPTOP_CLASS);
-       device->driver_data = topstar;
        topstar->device = device;
 
        err = topstar_acpi_init(topstar);
@@ -339,14 +341,15 @@ err_free:
        return err;
 }
 
-static void topstar_acpi_remove(struct acpi_device *device)
+static void topstar_acpi_remove(struct platform_device *pdev)
 {
-       struct topstar_laptop *topstar = acpi_driver_data(device);
+       struct topstar_laptop *topstar = platform_get_drvdata(pdev);
 
        if (led_workaround)
                topstar_led_exit(topstar);
 
-       acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY, topstar_acpi_notify);
+       acpi_dev_remove_notify_handler(ACPI_COMPANION(&pdev->dev),
+                                      ACPI_DEVICE_NOTIFY, topstar_acpi_notify);
        topstar_input_exit(topstar);
        topstar_platform_exit(topstar);
        topstar_acpi_exit(topstar);
@@ -361,13 +364,12 @@ static const struct acpi_device_id topstar_device_ids[] = {
 };
 MODULE_DEVICE_TABLE(acpi, topstar_device_ids);
 
-static struct acpi_driver topstar_acpi_driver = {
-       .name = "Topstar laptop ACPI driver",
-       .class = TOPSTAR_LAPTOP_CLASS,
-       .ids = topstar_device_ids,
-       .ops = {
-               .add = topstar_acpi_add,
-               .remove = topstar_acpi_remove,
+static struct platform_driver topstar_acpi_driver = {
+       .probe = topstar_acpi_probe,
+       .remove = topstar_acpi_remove,
+       .driver = {
+               .name = "Topstar laptop ACPI driver",
+               .acpi_match_table = topstar_device_ids,
        },
 };
 
@@ -379,7 +381,7 @@ static int __init topstar_laptop_init(void)
        if (ret < 0)
                return ret;
 
-       ret = acpi_bus_register_driver(&topstar_acpi_driver);
+       ret = platform_driver_register(&topstar_acpi_driver);
        if (ret < 0)
                goto err_driver_unreg;
 
@@ -393,7 +395,7 @@ err_driver_unreg:
 
 static void __exit topstar_laptop_exit(void)
 {
-       acpi_bus_unregister_driver(&topstar_acpi_driver);
+       platform_driver_unregister(&topstar_acpi_driver);
        platform_driver_unregister(&topstar_platform_driver);
 }