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Thomas Renningerc3d6de62008-08-01 17:37:55 +02001/*
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
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +020010 * assigned
Thomas Renningerc3d6de62008-08-01 17:37:55 +020011 *
12 * After PCI devices are glued with ACPI devices
Alexander Chiang1e4cffe2009-06-10 19:56:00 +000013 * acpi_get_pci_dev() can be called to identify ACPI graphics
Thomas Renningerc3d6de62008-08-01 17:37:55 +020014 * 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
Zhang Rui677bd812010-12-06 15:04:21 +080020 * backlight switching supporting driver calls:
Thomas Renningerc3d6de62008-08-01 17:37:55 +020021 * 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,
Zhang Rui677bd812010-12-06 15:04:21 +080027 * sony_acpi,... can take care about backlight brightness.
Thomas Renningerc3d6de62008-08-01 17:37:55 +020028 *
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
Paul Gortmaker214f2c92011-10-26 16:22:14 -040036#include <linux/export.h>
Thomas Renningerc3d6de62008-08-01 17:37:55 +020037#include <linux/acpi.h>
38#include <linux/dmi.h>
Alexander Chiang1e4cffe2009-06-10 19:56:00 +000039#include <linux/pci.h>
Thomas Renningerc3d6de62008-08-01 17:37:55 +020040
Len Browna192a952009-07-28 16:45:54 -040041#define PREFIX "ACPI: "
42
Thomas Renningerc3d6de62008-08-01 17:37:55 +020043ACPI_MODULE_NAME("video");
Thomas Renningerc3d6de62008-08-01 17:37:55 +020044#define _COMPONENT ACPI_VIDEO_COMPONENT
45
46static long acpi_video_support;
47static bool acpi_video_caps_checked;
48
49static acpi_status
50acpi_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;
Zhang Rui98758fa2009-03-12 16:57:11 +080061 if (ACPI_FAILURE(acpi_get_handle(handle, "_BQC", &h_dummy)))
Zhang Ruie9f74c42010-09-03 10:08:50 +080062 printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
63 "cannot determine initial brightness\n");
Thomas Renningerc3d6de62008-08-01 17:37:55 +020064 /* 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 */
78long 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
Michael Karchered764e72011-02-12 01:40:16 +010086 /* 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
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +020091 /* Is this device able to retrieve a video ROM ? */
Thomas Renningerc3d6de62008-08-01 17:37:55 +020092 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
93 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
94
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +020095 /* Is this device able to configure which video head to be POSTed ? */
Thomas Renningerc3d6de62008-08-01 17:37:55 +020096 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,
Lin Ming22635762009-11-13 10:06:08 +0800104 ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200105 &video_caps, NULL);
106
107 return video_caps;
108}
109EXPORT_SYMBOL(acpi_is_video_device);
110
111static acpi_status
112find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
113{
114 long *cap = context;
Alexander Chiang1e4cffe2009-06-10 19:56:00 +0000115 struct pci_dev *dev;
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200116 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)) {
Alexander Chiang1e4cffe2009-06-10 19:56:00 +0000126 dev = acpi_get_pci_dev(handle);
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200127 if (!dev)
128 return AE_OK;
Alexander Chiang1e4cffe2009-06-10 19:56:00 +0000129 pci_dev_put(dev);
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200130 *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
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +0200140 * summarized and returned. This is cached and done only once.
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200141 */
142long 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,
Lin Ming22635762009-11-13 10:06:08 +0800154 ACPI_UINT32_MAX, find_video, NULL,
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200155 &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 |=
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200164 * 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,
Lin Ming22635762009-11-13 10:06:08 +0800174 ACPI_UINT32_MAX, find_video, NULL,
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200175 &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}
183EXPORT_SYMBOL(acpi_video_get_capabilities);
184
185/* Returns true if video.ko can do backlight switching */
186int 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}
210EXPORT_SYMBOL(acpi_video_backlight_support);
211
212/*
Zhang Rui677bd812010-12-06 15:04:21 +0800213 * Use acpi_backlight=vendor/video to force that backlight switching
214 * is processed by vendor specific acpi drivers or video.ko driver.
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200215 */
Roel Kluin8a383ef2008-12-09 20:45:30 +0100216static int __init acpi_backlight(char *str)
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200217{
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 |=
Kamal Mostafaeeb4bcb2010-05-01 12:09:49 -0700226 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
Thomas Renningerc3d6de62008-08-01 17:37:55 +0200227 }
228 return 1;
229}
230__setup("acpi_backlight=", acpi_backlight);