ASoC: tlv312aic23: unbreak resume
[zen-stable.git] / drivers / acpi / video_detect.c
blobf3f0fe7e255a23ef679f718324cbf9e2f16e3f31
1 /*
2 * Copyright (C) 2008 SuSE Linux Products GmbH
3 * Thomas Renninger <trenn@suse.de>
5 * May be copied or modified under the terms of the GNU General Public License
7 * video_detect.c:
8 * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
9 * There a Linux specific (Spec does not provide a HID for video devices) is
10 * assigned
12 * After PCI devices are glued with ACPI devices
13 * acpi_get_pci_dev() can be called to identify ACPI graphics
14 * devices for which a real graphics card is plugged in
16 * Now acpi_video_get_capabilities() can be called to check which
17 * capabilities the graphics cards plugged in support. The check for general
18 * video capabilities will be triggered by the first caller of
19 * acpi_video_get_capabilities(NULL); which will happen when the first
20 * backlight switching supporting driver calls:
21 * acpi_video_backlight_support();
23 * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
24 * are available, video.ko should be used to handle the device.
26 * Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi,
27 * sony_acpi,... can take care about backlight brightness.
29 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
30 * this file will not be compiled, acpi_video_get_capabilities() and
31 * acpi_video_backlight_support() will always return 0 and vendor specific
32 * drivers always can handle backlight.
36 #include <linux/export.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/pci.h>
41 #define PREFIX "ACPI: "
43 ACPI_MODULE_NAME("video");
44 #define _COMPONENT ACPI_VIDEO_COMPONENT
46 static long acpi_video_support;
47 static bool acpi_video_caps_checked;
49 static acpi_status
50 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
51 void **retyurn_value)
53 long *cap = context;
54 acpi_handle h_dummy;
56 if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) &&
57 ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) {
58 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
59 "support\n"));
60 *cap |= ACPI_VIDEO_BACKLIGHT;
61 if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
62 printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
63 "cannot determine initial brightness\n");
64 /* We have backlight support, no need to scan further */
65 return AE_CTRL_TERMINATE;
67 return 0;
70 /* Returns true if the device is a video device which can be handled by
71 * video.ko.
72 * The device will get a Linux specific CID added in scan.c to
73 * identify the device as an ACPI graphics device
74 * Be aware that the graphics device may not be physically present
75 * Use acpi_video_get_capabilities() to detect general ACPI video
76 * capabilities of present cards
78 long acpi_is_video_device(struct acpi_device *device)
80 acpi_handle h_dummy;
81 long video_caps = 0;
83 if (!device)
84 return 0;
86 /* Is this device able to support video switching ? */
87 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) ||
88 ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
89 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
91 /* Is this device able to retrieve a video ROM ? */
92 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
93 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
95 /* Is this device able to configure which video head to be POSTed ? */
96 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
97 ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
98 ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
99 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
101 /* Only check for backlight functionality if one of the above hit. */
102 if (video_caps)
103 acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
104 ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
105 &video_caps, NULL);
107 return video_caps;
109 EXPORT_SYMBOL(acpi_is_video_device);
111 static acpi_status
112 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
114 long *cap = context;
115 struct pci_dev *dev;
116 struct acpi_device *acpi_dev;
118 const struct acpi_device_id video_ids[] = {
119 {ACPI_VIDEO_HID, 0},
120 {"", 0},
122 if (acpi_bus_get_device(handle, &acpi_dev))
123 return AE_OK;
125 if (!acpi_match_device_ids(acpi_dev, video_ids)) {
126 dev = acpi_get_pci_dev(handle);
127 if (!dev)
128 return AE_OK;
129 pci_dev_put(dev);
130 *cap |= acpi_is_video_device(acpi_dev);
132 return AE_OK;
136 * Returns the video capabilities of a specific ACPI graphics device
138 * if NULL is passed as argument all ACPI devices are enumerated and
139 * all graphics capabilities of physically present devices are
140 * summarized and returned. This is cached and done only once.
142 long acpi_video_get_capabilities(acpi_handle graphics_handle)
144 long caps = 0;
145 struct acpi_device *tmp_dev;
146 acpi_status status;
148 if (acpi_video_caps_checked && graphics_handle == NULL)
149 return acpi_video_support;
151 if (!graphics_handle) {
152 /* Only do the global walk through all graphics devices once */
153 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
154 ACPI_UINT32_MAX, find_video, NULL,
155 &caps, NULL);
156 /* There might be boot param flags set already... */
157 acpi_video_support |= caps;
158 acpi_video_caps_checked = 1;
159 /* Add blacklists here. Be careful to use the right *DMI* bits
160 * to still be able to override logic via boot params, e.g.:
162 * if (dmi_name_in_vendors("XY")) {
163 * acpi_video_support |=
164 * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
167 } else {
168 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
169 if (ACPI_FAILURE(status)) {
170 ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
171 return 0;
173 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
174 ACPI_UINT32_MAX, find_video, NULL,
175 &caps, NULL);
177 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
178 graphics_handle ? caps : acpi_video_support,
179 graphics_handle ? "on device " : "in general",
180 graphics_handle ? acpi_device_bid(tmp_dev) : ""));
181 return caps;
183 EXPORT_SYMBOL(acpi_video_get_capabilities);
185 /* Returns true if video.ko can do backlight switching */
186 int acpi_video_backlight_support(void)
189 * We must check whether the ACPI graphics device is physically plugged
190 * in. Therefore this must be called after binding PCI and ACPI devices
192 if (!acpi_video_caps_checked)
193 acpi_video_get_capabilities(NULL);
195 /* First check for boot param -> highest prio */
196 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
197 return 0;
198 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
199 return 1;
201 /* Then check for DMI blacklist -> second highest prio */
202 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
203 return 0;
204 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
205 return 1;
207 /* Then go the default way */
208 return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
210 EXPORT_SYMBOL(acpi_video_backlight_support);
213 * Use acpi_backlight=vendor/video to force that backlight switching
214 * is processed by vendor specific acpi drivers or video.ko driver.
216 static int __init acpi_backlight(char *str)
218 if (str == NULL || *str == '\0')
219 return 1;
220 else {
221 if (!strcmp("vendor", str))
222 acpi_video_support |=
223 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
224 if (!strcmp("video", str))
225 acpi_video_support |=
226 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
228 return 1;
230 __setup("acpi_backlight=", acpi_backlight);