/* * Copyright (C) 2008 SuSE Linux Products GmbH * Thomas Renninger * * May be copied or modified under the terms of the GNU General Public License * * video_detect.c: * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c * There a Linux specific (Spec does not provide a HID for video devices) is * assigned * * 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 * * Now acpi_video_get_capabilities() can be called to check which * capabilities the graphics cards plugged in support. The check for general * video capabilities will be triggered by the first caller of * acpi_video_get_capabilities(NULL); which will happen when the first * backlight switching supporting driver calls: * acpi_video_backlight_support(); * * 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_acpi, * sony_acpi,... can take care about backlight brightness. * * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m) * this file will not be compiled, acpi_video_get_capabilities() and * acpi_video_backlight_support() will always return 0 and vendor specific * drivers always can handle backlight. * */ #include #include #include #include #define PREFIX "ACPI: " ACPI_MODULE_NAME("video"); #define _COMPONENT ACPI_VIDEO_COMPONENT static long acpi_video_support; static bool acpi_video_caps_checked; static acpi_status acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context, void **retyurn_value) { long *cap = context; acpi_handle h_dummy; if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) && ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) { ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight " "support\n")); *cap |= ACPI_VIDEO_BACKLIGHT; if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy))) printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, " "cannot determine initial brightness\n"); /* We have backlight support, no need to scan further */ return AE_CTRL_TERMINATE; } return 0; } /* Returns true if the device is a video device which can be handled by * video.ko. * The device will get a Linux specific CID added in scan.c to * identify the device as an ACPI graphics device * Be aware that the graphics device may not be physically present * Use acpi_video_get_capabilities() to detect general ACPI video * capabilities of present cards */ long acpi_is_video_device(struct acpi_device *device) { acpi_handle h_dummy; long video_caps = 0; if (!device) return 0; /* Is this device able to support video switching ? */ if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) || ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy))) video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING; /* Is this device able to retrieve a video ROM ? */ if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy))) video_caps |= ACPI_VIDEO_ROM_AVAILABLE; /* Is this device able to configure which video head to be POSTed ? */ if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) && ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) && ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy))) video_caps |= ACPI_VIDEO_DEVICE_POSTING; /* Only check for backlight functionality if one of the above hit. */ if (video_caps) acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle, ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL, &video_caps, NULL); return video_caps; } EXPORT_SYMBOL(acpi_is_video_device); static acpi_status find_video(acpi_handle handle, u32 lvl, void *context, void **rv) { long *cap = context; struct pci_dev *dev; struct acpi_device *acpi_dev; const struct acpi_device_id video_ids[] = { {ACPI_VIDEO_HID, 0}, {"", 0}, }; if (acpi_bus_get_device(handle, &acpi_dev)) return AE_OK; if (!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(acpi_dev); } return AE_OK; } /* * Returns the video capabilities of a specific ACPI graphics device * * if NULL is passed as argument all ACPI devices are enumerated and * all graphics capabilities of physically present devices are * summarized and returned. This is cached and done only once. */ long acpi_video_get_capabilities(acpi_handle graphics_handle) { long caps = 0; struct acpi_device *tmp_dev; acpi_status status; if (acpi_video_caps_checked && graphics_handle == NULL) return acpi_video_support; if (!graphics_handle) { /* Only do the global walk through all graphics devices once */ acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX, find_video, NULL, &caps, NULL); /* There might be boot param flags set already... */ acpi_video_support |= caps; acpi_video_caps_checked = 1; /* Add blacklists here. Be careful to use the right *DMI* bits * to still be able to override logic via boot params, e.g.: * * if (dmi_name_in_vendors("XY")) { * acpi_video_support |= * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; *} */ } else { status = acpi_bus_get_device(graphics_handle, &tmp_dev); if (ACPI_FAILURE(status)) { ACPI_EXCEPTION((AE_INFO, status, "Invalid device")); return 0; } acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle, ACPI_UINT32_MAX, find_video, NULL, &caps, NULL); } ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n", graphics_handle ? caps : acpi_video_support, graphics_handle ? "on device " : "in general", graphics_handle ? acpi_device_bid(tmp_dev) : "")); return caps; } EXPORT_SYMBOL(acpi_video_get_capabilities); /* Returns true if video.ko can do backlight switching */ int acpi_video_backlight_support(void) { /* * We must check whether the ACPI graphics device is physically plugged * in. Therefore this must be called after binding PCI and ACPI devices */ if (!acpi_video_caps_checked) acpi_video_get_capabilities(NULL); /* First check for boot param -> highest prio */ if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR) return 0; else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO) return 1; /* Then check for DMI blacklist -> second highest prio */ if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR) return 0; else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO) return 1; /* Then go the default way */ return acpi_video_support & ACPI_VIDEO_BACKLIGHT; } EXPORT_SYMBOL(acpi_video_backlight_support); /* * Use acpi_backlight=vendor/video to force that backlight switching * is processed by vendor specific acpi drivers or video.ko driver. */ static int __init acpi_backlight(char *str) { if (str == NULL || *str == '\0') return 1; else { if (!strcmp("vendor", str)) acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; if (!strcmp("video", str)) acpi_video_support |= ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; } return 1; } __setup("acpi_backlight=", acpi_backlight);