platform/chrome: Convert ChromeOS privacy-screen driver to platform

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 ChromeOS privacy-screen 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@intel.com>
Link: https://lore.kernel.org/r/1963835.tdWV9SEqCh@rafael.j.wysocki
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
This commit is contained in:
Rafael J. Wysocki 2026-03-05 20:37:54 +01:00 committed by Tzung-Bi Shih
parent 286386820d
commit d3c2872ae3

View File

@ -12,6 +12,7 @@
*/ */
#include <linux/acpi.h> #include <linux/acpi.h>
#include <linux/platform_device.h>
#include <drm/drm_privacy_screen_driver.h> #include <drm/drm_privacy_screen_driver.h>
/* /*
@ -32,11 +33,10 @@ chromeos_privacy_screen_get_hw_state(struct drm_privacy_screen
*drm_privacy_screen) *drm_privacy_screen)
{ {
union acpi_object *obj; union acpi_object *obj;
acpi_handle handle;
struct device *privacy_screen = struct device *privacy_screen =
drm_privacy_screen_get_drvdata(drm_privacy_screen); drm_privacy_screen_get_drvdata(drm_privacy_screen);
acpi_handle handle = ACPI_HANDLE(privacy_screen);
handle = acpi_device_handle(to_acpi_device(privacy_screen));
obj = acpi_evaluate_dsm(handle, &chromeos_privacy_screen_dsm_guid, obj = acpi_evaluate_dsm(handle, &chromeos_privacy_screen_dsm_guid,
PRIV_SCRN_DSM_REVID, PRIV_SCRN_DSM_REVID,
PRIV_SCRN_DSM_FN_GET_STATUS, NULL); PRIV_SCRN_DSM_FN_GET_STATUS, NULL);
@ -65,11 +65,9 @@ chromeos_privacy_screen_set_sw_state(struct drm_privacy_screen
enum drm_privacy_screen_status state) enum drm_privacy_screen_status state)
{ {
union acpi_object *obj = NULL; union acpi_object *obj = NULL;
acpi_handle handle;
struct device *privacy_screen = struct device *privacy_screen =
drm_privacy_screen_get_drvdata(drm_privacy_screen); drm_privacy_screen_get_drvdata(drm_privacy_screen);
acpi_handle handle = ACPI_HANDLE(privacy_screen);
handle = acpi_device_handle(to_acpi_device(privacy_screen));
if (state == PRIVACY_SCREEN_DISABLED) { if (state == PRIVACY_SCREEN_DISABLED) {
obj = acpi_evaluate_dsm(handle, obj = acpi_evaluate_dsm(handle,
@ -104,30 +102,28 @@ static const struct drm_privacy_screen_ops chromeos_privacy_screen_ops = {
.set_sw_state = chromeos_privacy_screen_set_sw_state, .set_sw_state = chromeos_privacy_screen_set_sw_state,
}; };
static int chromeos_privacy_screen_add(struct acpi_device *adev) static int chromeos_privacy_screen_probe(struct platform_device *pdev)
{ {
struct drm_privacy_screen *drm_privacy_screen = struct drm_privacy_screen *drm_privacy_screen =
drm_privacy_screen_register(&adev->dev, drm_privacy_screen_register(&pdev->dev,
&chromeos_privacy_screen_ops, &chromeos_privacy_screen_ops,
&adev->dev); &pdev->dev);
if (IS_ERR(drm_privacy_screen)) { if (IS_ERR(drm_privacy_screen)) {
dev_err(&adev->dev, "Error registering privacy-screen\n"); dev_err(&pdev->dev, "Error registering privacy-screen\n");
return PTR_ERR(drm_privacy_screen); return PTR_ERR(drm_privacy_screen);
} }
adev->driver_data = drm_privacy_screen; platform_set_drvdata(pdev, drm_privacy_screen);
dev_info(&adev->dev, "registered privacy-screen '%s'\n", dev_info(&pdev->dev, "registered privacy-screen '%s'\n",
dev_name(&drm_privacy_screen->dev)); dev_name(&drm_privacy_screen->dev));
return 0; return 0;
} }
static void chromeos_privacy_screen_remove(struct acpi_device *adev) static void chromeos_privacy_screen_remove(struct platform_device *pdev)
{ {
struct drm_privacy_screen *drm_privacy_screen = acpi_driver_data(adev); drm_privacy_screen_unregister(platform_get_drvdata(pdev));
drm_privacy_screen_unregister(drm_privacy_screen);
} }
static const struct acpi_device_id chromeos_privacy_screen_device_ids[] = { static const struct acpi_device_id chromeos_privacy_screen_device_ids[] = {
@ -136,17 +132,16 @@ static const struct acpi_device_id chromeos_privacy_screen_device_ids[] = {
}; };
MODULE_DEVICE_TABLE(acpi, chromeos_privacy_screen_device_ids); MODULE_DEVICE_TABLE(acpi, chromeos_privacy_screen_device_ids);
static struct acpi_driver chromeos_privacy_screen_driver = { static struct platform_driver chromeos_privacy_screen_driver = {
.name = "chromeos_privacy_screen_driver", .probe = chromeos_privacy_screen_probe,
.class = "ChromeOS", .remove = chromeos_privacy_screen_remove,
.ids = chromeos_privacy_screen_device_ids, .driver = {
.ops = { .name = "chromeos_privacy_screen_driver",
.add = chromeos_privacy_screen_add, .acpi_match_table = chromeos_privacy_screen_device_ids,
.remove = chromeos_privacy_screen_remove,
}, },
}; };
module_acpi_driver(chromeos_privacy_screen_driver); module_platform_driver(chromeos_privacy_screen_driver);
MODULE_LICENSE("GPL v2"); MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ChromeOS ACPI Privacy Screen driver"); MODULE_DESCRIPTION("ChromeOS ACPI Privacy Screen driver");
MODULE_AUTHOR("Rajat Jain <rajatja@google.com>"); MODULE_AUTHOR("Rajat Jain <rajatja@google.com>");