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c3d6de69 TR |
1 | /* |
2 | * Copyright (C) 2008 SuSE Linux Products GmbH | |
3 | * Thomas Renninger <trenn@suse.de> | |
4 | * | |
5 | * May be copied or modified under the terms of the GNU General Public License | |
6 | * | |
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 | |
94e2bd68 | 10 | * assigned |
c3d6de69 TR |
11 | * |
12 | * After PCI devices are glued with ACPI devices | |
1e4cffe7 | 13 | * acpi_get_pci_dev() can be called to identify ACPI graphics |
c3d6de69 TR |
14 | * devices for which a real graphics card is plugged in |
15 | * | |
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 | |
677bd810 | 20 | * backlight switching supporting driver calls: |
c3d6de69 TR |
21 | * acpi_video_backlight_support(); |
22 | * | |
23 | * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B) | |
24 | * are available, video.ko should be used to handle the device. | |
25 | * | |
26 | * Otherwise vendor specific drivers like thinkpad_acpi, asus_acpi, | |
677bd810 | 27 | * sony_acpi,... can take care about backlight brightness. |
c3d6de69 TR |
28 | * |
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. | |
33 | * | |
34 | */ | |
35 | ||
214f2c90 | 36 | #include <linux/export.h> |
c3d6de69 TR |
37 | #include <linux/acpi.h> |
38 | #include <linux/dmi.h> | |
1e4cffe7 | 39 | #include <linux/pci.h> |
c3d6de69 | 40 | |
a192a958 LB |
41 | #define PREFIX "ACPI: " |
42 | ||
c3d6de69 | 43 | ACPI_MODULE_NAME("video"); |
c3d6de69 TR |
44 | #define _COMPONENT ACPI_VIDEO_COMPONENT |
45 | ||
46 | static long acpi_video_support; | |
47 | static bool acpi_video_caps_checked; | |
48 | ||
49 | static acpi_status | |
50 | acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context, | |
51 | void **retyurn_value) | |
52 | { | |
53 | long *cap = context; | |
54 | acpi_handle h_dummy; | |
55 | ||
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; | |
98758faf | 61 | if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy))) |
e9f74c48 ZR |
62 | printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, " |
63 | "cannot determine initial brightness\n"); | |
c3d6de69 TR |
64 | /* We have backlight support, no need to scan further */ |
65 | return AE_CTRL_TERMINATE; | |
66 | } | |
67 | return 0; | |
68 | } | |
69 | ||
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 | |
77 | */ | |
78 | long acpi_is_video_device(struct acpi_device *device) | |
79 | { | |
80 | acpi_handle h_dummy; | |
81 | long video_caps = 0; | |
82 | ||
83 | if (!device) | |
84 | return 0; | |
85 | ||
ed764e7c MK |
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; | |
90 | ||
94e2bd68 | 91 | /* Is this device able to retrieve a video ROM ? */ |
c3d6de69 TR |
92 | if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy))) |
93 | video_caps |= ACPI_VIDEO_ROM_AVAILABLE; | |
94 | ||
94e2bd68 | 95 | /* Is this device able to configure which video head to be POSTed ? */ |
c3d6de69 TR |
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; | |
100 | ||
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, | |
2263576c | 104 | ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL, |
c3d6de69 TR |
105 | &video_caps, NULL); |
106 | ||
107 | return video_caps; | |
108 | } | |
109 | EXPORT_SYMBOL(acpi_is_video_device); | |
110 | ||
111 | static acpi_status | |
112 | find_video(acpi_handle handle, u32 lvl, void *context, void **rv) | |
113 | { | |
114 | long *cap = context; | |
1e4cffe7 | 115 | struct pci_dev *dev; |
c3d6de69 TR |
116 | struct acpi_device *acpi_dev; |
117 | ||
118 | const struct acpi_device_id video_ids[] = { | |
119 | {ACPI_VIDEO_HID, 0}, | |
120 | {"", 0}, | |
121 | }; | |
122 | if (acpi_bus_get_device(handle, &acpi_dev)) | |
123 | return AE_OK; | |
124 | ||
125 | if (!acpi_match_device_ids(acpi_dev, video_ids)) { | |
1e4cffe7 | 126 | dev = acpi_get_pci_dev(handle); |
c3d6de69 TR |
127 | if (!dev) |
128 | return AE_OK; | |
1e4cffe7 | 129 | pci_dev_put(dev); |
c3d6de69 TR |
130 | *cap |= acpi_is_video_device(acpi_dev); |
131 | } | |
132 | return AE_OK; | |
133 | } | |
134 | ||
135 | /* | |
136 | * Returns the video capabilities of a specific ACPI graphics device | |
137 | * | |
138 | * if NULL is passed as argument all ACPI devices are enumerated and | |
139 | * all graphics capabilities of physically present devices are | |
94e2bd68 | 140 | * summarized and returned. This is cached and done only once. |
c3d6de69 TR |
141 | */ |
142 | long acpi_video_get_capabilities(acpi_handle graphics_handle) | |
143 | { | |
144 | long caps = 0; | |
145 | struct acpi_device *tmp_dev; | |
146 | acpi_status status; | |
147 | ||
148 | if (acpi_video_caps_checked && graphics_handle == NULL) | |
149 | return acpi_video_support; | |
150 | ||
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, | |
2263576c | 154 | ACPI_UINT32_MAX, find_video, NULL, |
c3d6de69 TR |
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.: | |
161 | * | |
162 | * if (dmi_name_in_vendors("XY")) { | |
163 | * acpi_video_support |= | |
c3d6de69 TR |
164 | * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; |
165 | *} | |
166 | */ | |
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; | |
172 | } | |
173 | acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle, | |
2263576c | 174 | ACPI_UINT32_MAX, find_video, NULL, |
c3d6de69 TR |
175 | &caps, NULL); |
176 | } | |
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; | |
182 | } | |
183 | EXPORT_SYMBOL(acpi_video_get_capabilities); | |
184 | ||
185 | /* Returns true if video.ko can do backlight switching */ | |
186 | int acpi_video_backlight_support(void) | |
187 | { | |
188 | /* | |
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 | |
191 | */ | |
192 | if (!acpi_video_caps_checked) | |
193 | acpi_video_get_capabilities(NULL); | |
194 | ||
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; | |
200 | ||
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; | |
206 | ||
207 | /* Then go the default way */ | |
208 | return acpi_video_support & ACPI_VIDEO_BACKLIGHT; | |
209 | } | |
210 | EXPORT_SYMBOL(acpi_video_backlight_support); | |
211 | ||
212 | /* | |
677bd810 ZR |
213 | * Use acpi_backlight=vendor/video to force that backlight switching |
214 | * is processed by vendor specific acpi drivers or video.ko driver. | |
c3d6de69 | 215 | */ |
8a383ef0 | 216 | static int __init acpi_backlight(char *str) |
c3d6de69 TR |
217 | { |
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 |= | |
eeb4bcb4 | 226 | ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; |
c3d6de69 TR |
227 | } |
228 | return 1; | |
229 | } | |
230 | __setup("acpi_backlight=", acpi_backlight); |