drivers/acpi/video_detect.c

Source file repositories/reference/linux-study-clean/drivers/acpi/video_detect.c

File Facts

System
Linux kernel
Corpus path
drivers/acpi/video_detect.c
Extension
.c
Size
29974 bytes
Lines
1086
Domain
Driver Families
Bucket
drivers/acpi
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#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)
{

Annotation

Implementation Notes