path: root/drivers/acpi/video_detect.c

/*
 *  Copyright (C) 2015       Red Hat Inc.
 *                           Hans de Goede <hdegoede@redhat.com>
 *  Copyright (C) 2008       SuSE Linux Products GmbH
 *                           Thomas Renninger <trenn@suse.de>
 *
 *  May be copied or modified under the terms of the GNU General Public License
 *
 * video_detect.c:
 * After PCI devices are glued with ACPI devices
 * acpi_get_pci_dev() can be called to identify ACPI graphics
 * devices for which a real graphics card is plugged in
 *
 * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
 * are available, video.ko should be used to handle the device.
 *
 * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
 * sony_acpi,... can take care about backlight brightness.
 *
 * Backlight drivers can use acpi_video_get_backlight_type() to determine which
 * driver should handle the backlight. RAW/GPU-driver backlight drivers must
 * use the acpi_video_backlight_use_native() helper for this.
 *
 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
 * this file will not be compiled and acpi_video_get_backlight_type() will
 * always return acpi_backlight_vendor.
 */

#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/apple-gmux.h>
#include <linux/backlight.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
#include <linux/pnp.h>
#include <linux/types.h>
#include <linux/workqueue.h>
#include <acpi/video.h>

static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;

static void acpi_video_parse_cmdline(void)
{
	if (!strcmp("vendor", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_vendor;
	if (!strcmp("video", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_video;
	if (!strcmp("native", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_native;
	if (!strcmp("nvidia_wmi_ec", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_nvidia_wmi_ec;
	if (!strcmp("apple_gmux", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_apple_gmux;
	if (!strcmp("dell_uart", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_dell_uart;
	if (!strcmp("none", acpi_video_backlight_string))
		acpi_backlight_cmdline = acpi_backlight_none;
}

static acpi_status
find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	struct acpi_device *acpi_dev = acpi_fetch_acpi_dev(handle);
	long *cap = context;
	struct pci_dev *dev;

	static const struct acpi_device_id video_ids[] = {
		{ACPI_VIDEO_HID, 0},
		{"", 0},
	};

	if (acpi_dev && !acpi_match_device_ids(acpi_dev, video_ids)) {
		dev = acpi_get_pci_dev(handle);
		if (!dev)
			return AE_OK;
		pci_dev_put(dev);
		*cap |= acpi_is_video_device(handle);
	}
	return AE_OK;
}

/* This depends on ACPI_WMI which is X86 only */
#ifdef CONFIG_X86
static bool nvidia_wmi_ec_supported(void)
{
	struct wmi_brightness_args args = {
		.mode = WMI_BRIGHTNESS_MODE_GET,
		.val = 0,
		.ret = 0,
	};
	struct acpi_buffer buf = { (acpi_size)sizeof(args), &args };
	acpi_status status;

	status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0,
				     WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf);
	if (ACPI_FAILURE(status))
		return false;

	/*
	 * If brightness is handled by the EC then nvidia-wmi-ec-backlight
	 * should be used, else the GPU driver(s) should be used.
	 */
	return args.ret == WMI_BRIGHTNESS_SOURCE_EC;
}
#else
static bool nvidia_wmi_ec_supported(void)
{
	return false;
}
#endif

/* Force to use vendor driver when the ACPI device is known to be
 * buggy */
static int video_detect_force_vendor(const struct dmi_system_id *d)
{
	acpi_backlight_dmi = acpi_backlight_vendor;
	return 0;
}

static int video_detect_force_video(const struct dmi_system_id *d)
{
	acpi_backlight_dmi = acpi_backlight_video;
	return 0;
}

static int video_detect_force_native(const struct dmi_system_id *d)
{
	acpi_backlight_dmi = acpi_backlight_native;
	return 0;
}

static int video_detect_portege_r100(const struct dmi_system_id *d)
{
	struct pci_dev *dev;
	/* Search for Trident CyberBlade XP4m32 to confirm Portégé R100 */
	dev = pci_get_device(PCI_VENDOR_ID_TRIDENT, 0x2100, NULL);
	if (<