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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 | ||
36 | #include <linux/acpi.h> | |
37 | #include <linux/dmi.h> | |
1e4cffe7 | 38 | #include <linux/pci.h> |
c3d6de69 | 39 | |
a192a958 LB |
40 | #define PREFIX "ACPI: " |
41 | ||
c3d6de69 | 42 | ACPI_MODULE_NAME("video"); |
c3d6de69 TR |
43 | #define _COMPONENT ACPI_VIDEO_COMPONENT |
44 | ||
45 | static long acpi_video_support; | |
46 | static bool acpi_video_caps_checked; | |
47 | ||
48 | static acpi_status | |
49 | acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context, | |
50 | void **retyurn_value) | |
51 | { | |
52 | long *cap = context; | |
53 | acpi_handle h_dummy; | |
54 | ||
55 | if (ACPI_SUCCESS(acpi_get_handle(handle, "_BCM", &h_dummy)) && | |
56 | ACPI_SUCCESS(acpi_get_handle(handle, "_BCL", &h_dummy))) { | |
57 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight " | |
58 | "support\n")); | |
59 | *cap |= ACPI_VIDEO_BACKLIGHT; | |
98758faf | 60 | if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy))) |
e9f74c48 ZR |
61 | printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, " |
62 | "cannot determine initial brightness\n"); | |
c3d6de69 TR |
63 | /* We have backlight support, no need to scan further */ |
64 | return AE_CTRL_TERMINATE; | |
65 | } | |
66 | return 0; | |
67 | } | |
68 | ||
69 | /* Returns true if the device is a video device which can be handled by | |
70 | * video.ko. | |
71 | * The device will get a Linux specific CID added in scan.c to | |
72 | * identify the device as an ACPI graphics device | |
73 | * Be aware that the graphics device may not be physically present | |
74 | * Use acpi_video_get_capabilities() to detect general ACPI video | |
75 | * capabilities of present cards | |
76 | */ | |
77 | long acpi_is_video_device(struct acpi_device *device) | |
78 | { | |
79 | acpi_handle h_dummy; | |
80 | long video_caps = 0; | |
81 | ||
82 | if (!device) | |
83 | return 0; | |
84 | ||
ed764e7c MK |
85 | /* Is this device able to support video switching ? */ |
86 | if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) || | |
87 | ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy))) | |
88 | video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING; | |
89 | ||
94e2bd68 | 90 | /* Is this device able to retrieve a video ROM ? */ |
c3d6de69 TR |
91 | if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy))) |
92 | video_caps |= ACPI_VIDEO_ROM_AVAILABLE; | |
93 | ||
94e2bd68 | 94 | /* Is this device able to configure which video head to be POSTed ? */ |
c3d6de69 TR |
95 | if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) && |
96 | ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) && | |
97 | ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy))) | |
98 | video_caps |= ACPI_VIDEO_DEVICE_POSTING; | |
99 | ||
100 | /* Only check for backlight functionality if one of the above hit. */ | |
101 | if (video_caps) | |
102 | acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle, | |
2263576c | 103 | ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL, |
c3d6de69 TR |
104 | &video_caps, NULL); |
105 | ||
106 | return video_caps; | |
107 | } | |
108 | EXPORT_SYMBOL(acpi_is_video_device); | |
109 | ||
110 | static acpi_status | |
111 | find_video(acpi_handle handle, u32 lvl, void *context, void **rv) | |
112 | { | |
113 | long *cap = context; | |
1e4cffe7 | 114 | struct pci_dev *dev; |
c3d6de69 TR |
115 | struct acpi_device *acpi_dev; |
116 | ||
117 | const struct acpi_device_id video_ids[] = { | |
118 | {ACPI_VIDEO_HID, 0}, | |
119 | {"", 0}, | |
120 | }; | |
121 | if (acpi_bus_get_device(handle, &acpi_dev)) | |
122 | return AE_OK; | |
123 | ||
124 | if (!acpi_match_device_ids(acpi_dev, video_ids)) { | |
1e4cffe7 | 125 | dev = acpi_get_pci_dev(handle); |
c3d6de69 TR |
126 | if (!dev) |
127 | return AE_OK; | |
1e4cffe7 | 128 | pci_dev_put(dev); |
c3d6de69 TR |
129 | *cap |= acpi_is_video_device(acpi_dev); |
130 | } | |
131 | return AE_OK; | |
132 | } | |
133 | ||
134 | /* | |
135 | * Returns the video capabilities of a specific ACPI graphics device | |
136 | * | |
137 | * if NULL is passed as argument all ACPI devices are enumerated and | |
138 | * all graphics capabilities of physically present devices are | |
94e2bd68 | 139 | * summarized and returned. This is cached and done only once. |
c3d6de69 TR |
140 | */ |
141 | long acpi_video_get_capabilities(acpi_handle graphics_handle) | |
142 | { | |
143 | long caps = 0; | |
144 | struct acpi_device *tmp_dev; | |
145 | acpi_status status; | |
146 | ||
147 | if (acpi_video_caps_checked && graphics_handle == NULL) | |
148 | return acpi_video_support; | |
149 | ||
150 | if (!graphics_handle) { | |
151 | /* Only do the global walk through all graphics devices once */ | |
152 | acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, | |
2263576c | 153 | ACPI_UINT32_MAX, find_video, NULL, |
c3d6de69 TR |
154 | &caps, NULL); |
155 | /* There might be boot param flags set already... */ | |
156 | acpi_video_support |= caps; | |
157 | acpi_video_caps_checked = 1; | |
158 | /* Add blacklists here. Be careful to use the right *DMI* bits | |
159 | * to still be able to override logic via boot params, e.g.: | |
160 | * | |
161 | * if (dmi_name_in_vendors("XY")) { | |
162 | * acpi_video_support |= | |
c3d6de69 TR |
163 | * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; |
164 | *} | |
165 | */ | |
166 | } else { | |
167 | status = acpi_bus_get_device(graphics_handle, &tmp_dev); | |
168 | if (ACPI_FAILURE(status)) { | |
169 | ACPI_EXCEPTION((AE_INFO, status, "Invalid device")); | |
170 | return 0; | |
171 | } | |
172 | acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle, | |
2263576c | 173 | ACPI_UINT32_MAX, find_video, NULL, |
c3d6de69 TR |
174 | &caps, NULL); |
175 | } | |
176 | ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n", | |
177 | graphics_handle ? caps : acpi_video_support, | |
178 | graphics_handle ? "on device " : "in general", | |
179 | graphics_handle ? acpi_device_bid(tmp_dev) : "")); | |
180 | return caps; | |
181 | } | |
182 | EXPORT_SYMBOL(acpi_video_get_capabilities); | |
183 | ||
184 | /* Returns true if video.ko can do backlight switching */ | |
185 | int acpi_video_backlight_support(void) | |
186 | { | |
187 | /* | |
188 | * We must check whether the ACPI graphics device is physically plugged | |
189 | * in. Therefore this must be called after binding PCI and ACPI devices | |
190 | */ | |
191 | if (!acpi_video_caps_checked) | |
192 | acpi_video_get_capabilities(NULL); | |
193 | ||
194 | /* First check for boot param -> highest prio */ | |
195 | if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR) | |
196 | return 0; | |
197 | else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO) | |
198 | return 1; | |
199 | ||
200 | /* Then check for DMI blacklist -> second highest prio */ | |
201 | if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR) | |
202 | return 0; | |
203 | else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO) | |
204 | return 1; | |
205 | ||
206 | /* Then go the default way */ | |
207 | return acpi_video_support & ACPI_VIDEO_BACKLIGHT; | |
208 | } | |
209 | EXPORT_SYMBOL(acpi_video_backlight_support); | |
210 | ||
211 | /* | |
677bd810 ZR |
212 | * Use acpi_backlight=vendor/video to force that backlight switching |
213 | * is processed by vendor specific acpi drivers or video.ko driver. | |
c3d6de69 | 214 | */ |
8a383ef0 | 215 | static int __init acpi_backlight(char *str) |
c3d6de69 TR |
216 | { |
217 | if (str == NULL || *str == '\0') | |
218 | return 1; | |
219 | else { | |
220 | if (!strcmp("vendor", str)) | |
221 | acpi_video_support |= | |
222 | ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; | |
223 | if (!strcmp("video", str)) | |
224 | acpi_video_support |= | |
eeb4bcb4 | 225 | ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; |
c3d6de69 TR |
226 | } |
227 | return 1; | |
228 | } | |
229 | __setup("acpi_backlight=", acpi_backlight); |