ACPI / APEI: fix error return code in ghes_probe()
[linux-3.10.git] / drivers / acpi / video_detect.c
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
10  * assigned
11  *
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
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
20  * backlight switching supporting driver calls:
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-laptop,
27  * sony_acpi,... can take care about backlight brightness.
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/export.h>
37 #include <linux/acpi.h>
38 #include <linux/dmi.h>
39 #include <linux/pci.h>
40
41 #define PREFIX "ACPI: "
42
43 ACPI_MODULE_NAME("video");
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;
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;
66         }
67         return 0;
68 }
69
70 /* Returns true if the ACPI object is a video device which can be
71  * handled by 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(acpi_handle handle)
79 {
80         acpi_handle h_dummy;
81         long video_caps = 0;
82
83         /* Is this device able to support video switching ? */
84         if (ACPI_SUCCESS(acpi_get_handle(handle, "_DOD", &h_dummy)) ||
85             ACPI_SUCCESS(acpi_get_handle(handle, "_DOS", &h_dummy)))
86                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
87
88         /* Is this device able to retrieve a video ROM ? */
89         if (ACPI_SUCCESS(acpi_get_handle(handle, "_ROM", &h_dummy)))
90                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
91
92         /* Is this device able to configure which video head to be POSTed ? */
93         if (ACPI_SUCCESS(acpi_get_handle(handle, "_VPO", &h_dummy)) &&
94             ACPI_SUCCESS(acpi_get_handle(handle, "_GPD", &h_dummy)) &&
95             ACPI_SUCCESS(acpi_get_handle(handle, "_SPD", &h_dummy)))
96                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
97
98         /* Only check for backlight functionality if one of the above hit. */
99         if (video_caps)
100                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
101                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
102                                     &video_caps, NULL);
103
104         return video_caps;
105 }
106 EXPORT_SYMBOL(acpi_is_video_device);
107
108 static acpi_status
109 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
110 {
111         long *cap = context;
112         struct pci_dev *dev;
113         struct acpi_device *acpi_dev;
114
115         const struct acpi_device_id video_ids[] = {
116                 {ACPI_VIDEO_HID, 0},
117                 {"", 0},
118         };
119         if (acpi_bus_get_device(handle, &acpi_dev))
120                 return AE_OK;
121
122         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
123                 dev = acpi_get_pci_dev(handle);
124                 if (!dev)
125                         return AE_OK;
126                 pci_dev_put(dev);
127                 *cap |= acpi_is_video_device(handle);
128         }
129         return AE_OK;
130 }
131
132 /* Force to use vendor driver when the ACPI device is known to be
133  * buggy */
134 static int video_detect_force_vendor(const struct dmi_system_id *d)
135 {
136         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
137         return 0;
138 }
139
140 static struct dmi_system_id video_detect_dmi_table[] = {
141         /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
142          * ACPI backlight device is used. This flag will definitively break
143          * the backlight interface (even the vendor interface) untill next
144          * reboot. It's why we should prevent video.ko from being used here
145          * and we can't rely on a later call to acpi_video_unregister().
146          */
147         {
148          .callback = video_detect_force_vendor,
149          .ident = "X360",
150          .matches = {
151                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
152                 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
153                 DMI_MATCH(DMI_BOARD_NAME, "X360"),
154                 },
155         },
156         {
157         .callback = video_detect_force_vendor,
158         .ident = "Asus UL30VT",
159         .matches = {
160                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
161                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
162                 },
163         },
164         {
165         .callback = video_detect_force_vendor,
166         .ident = "Asus UL30A",
167         .matches = {
168                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
169                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
170                 },
171         },
172         { },
173 };
174
175 /*
176  * Returns the video capabilities of a specific ACPI graphics device
177  *
178  * if NULL is passed as argument all ACPI devices are enumerated and
179  * all graphics capabilities of physically present devices are
180  * summarized and returned. This is cached and done only once.
181  */
182 long acpi_video_get_capabilities(acpi_handle graphics_handle)
183 {
184         long caps = 0;
185         struct acpi_device *tmp_dev;
186         acpi_status status;
187
188         if (acpi_video_caps_checked && graphics_handle == NULL)
189                 return acpi_video_support;
190
191         if (!graphics_handle) {
192                 /* Only do the global walk through all graphics devices once */
193                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
194                                     ACPI_UINT32_MAX, find_video, NULL,
195                                     &caps, NULL);
196                 /* There might be boot param flags set already... */
197                 acpi_video_support |= caps;
198                 acpi_video_caps_checked = 1;
199                 /* Add blacklists here. Be careful to use the right *DMI* bits
200                  * to still be able to override logic via boot params, e.g.:
201                  *
202                  *   if (dmi_name_in_vendors("XY")) {
203                  *      acpi_video_support |=
204                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
205                  *}
206                  */
207
208                 dmi_check_system(video_detect_dmi_table);
209         } else {
210                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
211                 if (ACPI_FAILURE(status)) {
212                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
213                         return 0;
214                 }
215                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
216                                     ACPI_UINT32_MAX, find_video, NULL,
217                                     &caps, NULL);
218         }
219         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
220                           graphics_handle ? caps : acpi_video_support,
221                           graphics_handle ? "on device " : "in general",
222                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
223         return caps;
224 }
225 EXPORT_SYMBOL(acpi_video_get_capabilities);
226
227 static void acpi_video_caps_check(void)
228 {
229         /*
230          * We must check whether the ACPI graphics device is physically plugged
231          * in. Therefore this must be called after binding PCI and ACPI devices
232          */
233         if (!acpi_video_caps_checked)
234                 acpi_video_get_capabilities(NULL);
235 }
236
237 /* Promote the vendor interface instead of the generic video module.
238  * This function allow DMI blacklists to be implemented by externals
239  * platform drivers instead of putting a big blacklist in video_detect.c
240  * After calling this function you will probably want to call
241  * acpi_video_unregister() to make sure the video module is not loaded
242  */
243 void acpi_video_dmi_promote_vendor(void)
244 {
245         acpi_video_caps_check();
246         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
247 }
248 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
249
250 /* To be called when a driver who previously promoted the vendor
251  * interface */
252 void acpi_video_dmi_demote_vendor(void)
253 {
254         acpi_video_caps_check();
255         acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
256 }
257 EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
258
259 /* Returns true if video.ko can do backlight switching */
260 int acpi_video_backlight_support(void)
261 {
262         acpi_video_caps_check();
263
264         /* First check for boot param -> highest prio */
265         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
266                 return 0;
267         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
268                 return 1;
269
270         /* Then check for DMI blacklist -> second highest prio */
271         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
272                 return 0;
273         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
274                 return 1;
275
276         /* Then go the default way */
277         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
278 }
279 EXPORT_SYMBOL(acpi_video_backlight_support);
280
281 /*
282  * Use acpi_backlight=vendor/video to force that backlight switching
283  * is processed by vendor specific acpi drivers or video.ko driver.
284  */
285 static int __init acpi_backlight(char *str)
286 {
287         if (str == NULL || *str == '\0')
288                 return 1;
289         else {
290                 if (!strcmp("vendor", str))
291                         acpi_video_support |=
292                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
293                 if (!strcmp("video", str))
294                         acpi_video_support |=
295                                 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
296         }
297         return 1;
298 }
299 __setup("acpi_backlight=", acpi_backlight);