1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
|
/*
* Copyright (C) 2008 SuSE Linux Products GmbH
* Thomas Renninger <trenn@suse.de>
*
* 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 (or display output) 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 and display output
* switching.
*
* 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 <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/pci.h>
#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 "ACPI brightness "
"control misses _BQC function\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,
&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,
&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_OUTPUT_SWITCHING_DMI_VENDOR;
* 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,
&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);
/*
* Returns true if video.ko can do display output switching.
* This does not work well/at all with binary graphics drivers
* which disable system io ranges and do it on their own.
*/
int acpi_video_display_switch_support(void)
{
if (!acpi_video_caps_checked)
acpi_video_get_capabilities(NULL);
if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR)
return 0;
else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO)
return 1;
if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR)
return 0;
else if (acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO)
return 1;
return acpi_video_support & ACPI_VIDEO_OUTPUT_SWITCHING;
}
EXPORT_SYMBOL(acpi_video_display_switch_support);
/*
* Use acpi_display_output=vendor/video or acpi_backlight=vendor/video
* To force that backlight or display output 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_OUTPUT_SWITCHING_FORCE_VIDEO;
}
return 1;
}
__setup("acpi_backlight=", acpi_backlight);
static int __init acpi_display_output(char *str)
{
if (str == NULL || *str == '\0')
return 1;
else {
if (!strcmp("vendor", str))
acpi_video_support |=
ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VENDOR;
if (!strcmp("video", str))
acpi_video_support |=
ACPI_VIDEO_OUTPUT_SWITCHING_FORCE_VIDEO;
}
return 1;
}
__setup("acpi_display_output=", acpi_display_output);
|
