Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

Linux/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 #include "internal.h"
 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 **return_value)
 52 {
 53         long *cap = context;
 54 
 55         if (acpi_has_method(handle, "_BCM") &&
 56             acpi_has_method(handle, "_BCL")) {
 57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
 58                                   "support\n"));
 59                 *cap |= ACPI_VIDEO_BACKLIGHT;
 60                 if (!acpi_has_method(handle, "_BQC"))
 61                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
 62                                 "cannot determine initial brightness\n");
 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 ACPI object is a video device which can be
 70  * handled by 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(acpi_handle handle)
 78 {
 79         long video_caps = 0;
 80 
 81         /* Is this device able to support video switching ? */
 82         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
 83                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
 84 
 85         /* Is this device able to retrieve a video ROM ? */
 86         if (acpi_has_method(handle, "_ROM"))
 87                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
 88 
 89         /* Is this device able to configure which video head to be POSTed ? */
 90         if (acpi_has_method(handle, "_VPO") &&
 91             acpi_has_method(handle, "_GPD") &&
 92             acpi_has_method(handle, "_SPD"))
 93                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
 94 
 95         /* Only check for backlight functionality if one of the above hit. */
 96         if (video_caps)
 97                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
 98                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
 99                                     &video_caps, NULL);
100 
101         return video_caps;
102 }
103 EXPORT_SYMBOL(acpi_is_video_device);
104 
105 static acpi_status
106 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
107 {
108         long *cap = context;
109         struct pci_dev *dev;
110         struct acpi_device *acpi_dev;
111 
112         const struct acpi_device_id video_ids[] = {
113                 {ACPI_VIDEO_HID, 0},
114                 {"", 0},
115         };
116         if (acpi_bus_get_device(handle, &acpi_dev))
117                 return AE_OK;
118 
119         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
120                 dev = acpi_get_pci_dev(handle);
121                 if (!dev)
122                         return AE_OK;
123                 pci_dev_put(dev);
124                 *cap |= acpi_is_video_device(handle);
125         }
126         return AE_OK;
127 }
128 
129 /* Force to use vendor driver when the ACPI device is known to be
130  * buggy */
131 static int video_detect_force_vendor(const struct dmi_system_id *d)
132 {
133         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
134         return 0;
135 }
136 
137 static struct dmi_system_id video_detect_dmi_table[] = {
138         /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
139          * ACPI backlight device is used. This flag will definitively break
140          * the backlight interface (even the vendor interface) untill next
141          * reboot. It's why we should prevent video.ko from being used here
142          * and we can't rely on a later call to acpi_video_unregister().
143          */
144         {
145          .callback = video_detect_force_vendor,
146          .ident = "X360",
147          .matches = {
148                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
149                 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
150                 DMI_MATCH(DMI_BOARD_NAME, "X360"),
151                 },
152         },
153         {
154         .callback = video_detect_force_vendor,
155         .ident = "Asus UL30VT",
156         .matches = {
157                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
158                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
159                 },
160         },
161         {
162         .callback = video_detect_force_vendor,
163         .ident = "Asus UL30A",
164         .matches = {
165                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
166                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
167                 },
168         },
169         { },
170 };
171 
172 /*
173  * Returns the video capabilities of a specific ACPI graphics device
174  *
175  * if NULL is passed as argument all ACPI devices are enumerated and
176  * all graphics capabilities of physically present devices are
177  * summarized and returned. This is cached and done only once.
178  */
179 long acpi_video_get_capabilities(acpi_handle graphics_handle)
180 {
181         long caps = 0;
182         struct acpi_device *tmp_dev;
183         acpi_status status;
184 
185         if (acpi_video_caps_checked && graphics_handle == NULL)
186                 return acpi_video_support;
187 
188         if (!graphics_handle) {
189                 /* Only do the global walk through all graphics devices once */
190                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
191                                     ACPI_UINT32_MAX, find_video, NULL,
192                                     &caps, NULL);
193                 /* There might be boot param flags set already... */
194                 acpi_video_support |= caps;
195                 acpi_video_caps_checked = 1;
196                 /* Add blacklists here. Be careful to use the right *DMI* bits
197                  * to still be able to override logic via boot params, e.g.:
198                  *
199                  *   if (dmi_name_in_vendors("XY")) {
200                  *      acpi_video_support |=
201                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
202                  *}
203                  */
204 
205                 dmi_check_system(video_detect_dmi_table);
206         } else {
207                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
208                 if (ACPI_FAILURE(status)) {
209                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
210                         return 0;
211                 }
212                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
213                                     ACPI_UINT32_MAX, find_video, NULL,
214                                     &caps, NULL);
215         }
216         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
217                           graphics_handle ? caps : acpi_video_support,
218                           graphics_handle ? "on device " : "in general",
219                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
220         return caps;
221 }
222 EXPORT_SYMBOL(acpi_video_get_capabilities);
223 
224 static void acpi_video_caps_check(void)
225 {
226         /*
227          * We must check whether the ACPI graphics device is physically plugged
228          * in. Therefore this must be called after binding PCI and ACPI devices
229          */
230         if (!acpi_video_caps_checked)
231                 acpi_video_get_capabilities(NULL);
232 }
233 
234 bool acpi_osi_is_win8(void)
235 {
236         return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
237 }
238 EXPORT_SYMBOL(acpi_osi_is_win8);
239 
240 /* Promote the vendor interface instead of the generic video module.
241  * This function allow DMI blacklists to be implemented by externals
242  * platform drivers instead of putting a big blacklist in video_detect.c
243  * After calling this function you will probably want to call
244  * acpi_video_unregister() to make sure the video module is not loaded
245  */
246 void acpi_video_dmi_promote_vendor(void)
247 {
248         acpi_video_caps_check();
249         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
250 }
251 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
252 
253 /* To be called when a driver who previously promoted the vendor
254  * interface */
255 void acpi_video_dmi_demote_vendor(void)
256 {
257         acpi_video_caps_check();
258         acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
259 }
260 EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
261 
262 /* Returns true if video.ko can do backlight switching */
263 int acpi_video_backlight_support(void)
264 {
265         acpi_video_caps_check();
266 
267         /* First check for boot param -> highest prio */
268         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
269                 return 0;
270         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
271                 return 1;
272 
273         /* Then check for DMI blacklist -> second highest prio */
274         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
275                 return 0;
276         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
277                 return 1;
278 
279         /* Then go the default way */
280         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
281 }
282 EXPORT_SYMBOL(acpi_video_backlight_support);
283 
284 /*
285  * Use acpi_backlight=vendor/video to force that backlight switching
286  * is processed by vendor specific acpi drivers or video.ko driver.
287  */
288 static int __init acpi_backlight(char *str)
289 {
290         if (str == NULL || *str == '\0')
291                 return 1;
292         else {
293                 if (!strcmp("vendor", str))
294                         acpi_video_support |=
295                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
296                 if (!strcmp("video", str))
297                         acpi_video_support |=
298                                 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
299         }
300         return 1;
301 }
302 __setup("acpi_backlight=", acpi_backlight);
303 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us