linux/drivers/gpu/drm/drm_privacy_screen_x86.c
Hans de Goede befe5404a0 drm/privacy-screen: Add X86 specific arch init code
Add X86 specific arch init code, which fills the privacy-screen lookup
table by checking for various vendor specific ACPI interfaces for
controlling the privacy-screen.

This initial version only checks for the Lenovo Thinkpad specific ACPI
methods for privacy-screen control.

Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211005202322.700909-4-hdegoede@redhat.com
2021-10-14 13:12:24 +02:00

87 lines
2.0 KiB
C

// SPDX-License-Identifier: MIT
/*
* Copyright (C) 2020 Red Hat, Inc.
*
* Authors:
* Hans de Goede <hdegoede@redhat.com>
*/
#include <linux/acpi.h>
#include <drm/drm_privacy_screen_machine.h>
#ifdef CONFIG_X86
static struct drm_privacy_screen_lookup arch_lookup;
struct arch_init_data {
struct drm_privacy_screen_lookup lookup;
bool (*detect)(void);
};
#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
void *context, void **return_value)
{
*(acpi_handle *)return_value = handle;
return AE_CTRL_TERMINATE;
}
static bool __init detect_thinkpad_privacy_screen(void)
{
union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
struct acpi_object_list args = { .count = 1, .pointer = &obj, };
acpi_handle ec_handle = NULL;
unsigned long long output;
acpi_status status;
/* Get embedded-controller handle */
status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
if (ACPI_FAILURE(status) || !ec_handle)
return false;
/* And call the privacy-screen get-status method */
status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
if (ACPI_FAILURE(status))
return false;
return (output & 0x10000) ? true : false;
}
#endif
static const struct arch_init_data arch_init_data[] __initconst = {
#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
{
.lookup = {
.dev_id = NULL,
.con_id = NULL,
.provider = "privacy_screen-thinkpad_acpi",
},
.detect = detect_thinkpad_privacy_screen,
},
#endif
};
void __init drm_privacy_screen_lookup_init(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
if (!arch_init_data[i].detect())
continue;
pr_info("Found '%s' privacy-screen provider\n",
arch_init_data[i].lookup.provider);
/* Make a copy because arch_init_data is __initconst */
arch_lookup = arch_init_data[i].lookup;
drm_privacy_screen_lookup_add(&arch_lookup);
break;
}
}
void drm_privacy_screen_lookup_exit(void)
{
if (arch_lookup.provider)
drm_privacy_screen_lookup_remove(&arch_lookup);
}
#endif /* ifdef CONFIG_X86 */