2 * Copyright (C) 2015 Red Hat Inc.
3 * Hans de Goede <hdegoede@redhat.com>
4 * Copyright (C) 2008 SuSE Linux Products GmbH
5 * Thomas Renninger <trenn@suse.de>
7 * May be copied or modified under the terms of the GNU General Public License
10 * After PCI devices are glued with ACPI devices
11 * acpi_get_pci_dev() can be called to identify ACPI graphics
12 * devices for which a real graphics card is plugged in
14 * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
15 * are available, video.ko should be used to handle the device.
17 * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
18 * sony_acpi,... can take care about backlight brightness.
20 * Backlight drivers can use acpi_video_get_backlight_type() to determine
21 * which driver should handle the backlight.
23 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
24 * this file will not be compiled and acpi_video_get_backlight_type() will
25 * always return acpi_backlight_vendor.
28 #include <linux/export.h>
29 #include <linux/acpi.h>
30 #include <linux/backlight.h>
31 #include <linux/dmi.h>
32 #include <linux/module.h>
33 #include <linux/pci.h>
34 #include <linux/types.h>
35 #include <linux/workqueue.h>
36 #include <acpi/video.h>
38 ACPI_MODULE_NAME("video");
39 #define _COMPONENT ACPI_VIDEO_COMPONENT
41 void acpi_video_unregister_backlight(void);
43 static bool backlight_notifier_registered;
44 static struct notifier_block backlight_nb;
45 static struct work_struct backlight_notify_work;
47 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
48 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
50 static void acpi_video_parse_cmdline(void)
52 if (!strcmp("vendor", acpi_video_backlight_string))
53 acpi_backlight_cmdline = acpi_backlight_vendor;
54 if (!strcmp("video", acpi_video_backlight_string))
55 acpi_backlight_cmdline = acpi_backlight_video;
56 if (!strcmp("native", acpi_video_backlight_string))
57 acpi_backlight_cmdline = acpi_backlight_native;
58 if (!strcmp("none", acpi_video_backlight_string))
59 acpi_backlight_cmdline = acpi_backlight_none;
63 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
67 struct acpi_device *acpi_dev;
69 static const struct acpi_device_id video_ids[] = {
73 if (acpi_bus_get_device(handle, &acpi_dev))
76 if (!acpi_match_device_ids(acpi_dev, video_ids)) {
77 dev = acpi_get_pci_dev(handle);
81 *cap |= acpi_is_video_device(handle);
86 /* Force to use vendor driver when the ACPI device is known to be
88 static int video_detect_force_vendor(const struct dmi_system_id *d)
90 acpi_backlight_dmi = acpi_backlight_vendor;
94 static int video_detect_force_video(const struct dmi_system_id *d)
96 acpi_backlight_dmi = acpi_backlight_video;
100 static int video_detect_force_native(const struct dmi_system_id *d)
102 acpi_backlight_dmi = acpi_backlight_native;
106 static const struct dmi_system_id video_detect_dmi_table[] = {
107 /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
108 * ACPI backlight device is used. This flag will definitively break
109 * the backlight interface (even the vendor interface) untill next
110 * reboot. It's why we should prevent video.ko from being used here
111 * and we can't rely on a later call to acpi_video_unregister().
114 .callback = video_detect_force_vendor,
117 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
118 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
119 DMI_MATCH(DMI_BOARD_NAME, "X360"),
123 .callback = video_detect_force_vendor,
124 .ident = "Asus UL30VT",
126 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
127 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
131 .callback = video_detect_force_vendor,
132 .ident = "Asus UL30A",
134 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
135 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
140 * These models have a working acpi_video backlight control, and using
141 * native backlight causes a regression where backlight does not work
142 * when userspace is not handling brightness key events. Disable
143 * native_backlight on these to fix this:
144 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
147 .callback = video_detect_force_video,
148 .ident = "ThinkPad T420",
150 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
151 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
155 .callback = video_detect_force_video,
156 .ident = "ThinkPad T520",
158 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
159 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
163 .callback = video_detect_force_video,
164 .ident = "ThinkPad X201s",
166 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
167 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
171 .callback = video_detect_force_video,
172 .ident = "ThinkPad X201T",
174 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
175 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
179 /* The native backlight controls do not work on some older machines */
181 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
182 .callback = video_detect_force_video,
183 .ident = "HP ENVY 15 Notebook",
185 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
186 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
190 .callback = video_detect_force_video,
191 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
193 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
194 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
198 .callback = video_detect_force_video,
199 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
201 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
202 DMI_MATCH(DMI_PRODUCT_NAME,
203 "370R4E/370R4V/370R5E/3570RE/370R5V"),
207 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
208 .callback = video_detect_force_video,
209 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
211 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
212 DMI_MATCH(DMI_PRODUCT_NAME,
213 "3570R/370R/470R/450R/510R/4450RV"),
217 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
218 .callback = video_detect_force_video,
219 .ident = "SAMSUNG 730U3E/740U3E",
221 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
222 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
226 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
227 .callback = video_detect_force_video,
228 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
230 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
231 DMI_MATCH(DMI_PRODUCT_NAME,
232 "900X3C/900X3D/900X3E/900X4C/900X4D"),
236 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
237 .callback = video_detect_force_video,
238 .ident = "Dell XPS14 L421X",
240 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
241 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
245 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
246 .callback = video_detect_force_video,
247 .ident = "Dell XPS15 L521X",
249 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
250 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
254 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
255 .callback = video_detect_force_video,
256 .ident = "SAMSUNG 530U4E/540U4E",
258 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
259 DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
263 /* Non win8 machines which need native backlight nevertheless */
265 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
266 .callback = video_detect_force_native,
267 .ident = "Lenovo Ideapad S405",
269 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
270 DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
274 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
275 .callback = video_detect_force_native,
276 .ident = "Lenovo Ideapad Z570",
278 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
279 DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
283 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
284 .callback = video_detect_force_native,
285 .ident = "Apple MacBook Pro 12,1",
287 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
288 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
292 .callback = video_detect_force_native,
293 .ident = "Dell Vostro V131",
295 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
296 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
302 /* This uses a workqueue to avoid various locking ordering issues */
303 static void acpi_video_backlight_notify_work(struct work_struct *work)
305 if (acpi_video_get_backlight_type() != acpi_backlight_video)
306 acpi_video_unregister_backlight();
309 static int acpi_video_backlight_notify(struct notifier_block *nb,
310 unsigned long val, void *bd)
312 struct backlight_device *backlight = bd;
314 /* A raw bl registering may change video -> native */
315 if (backlight->props.type == BACKLIGHT_RAW &&
316 val == BACKLIGHT_REGISTERED)
317 schedule_work(&backlight_notify_work);
323 * Determine which type of backlight interface to use on this system,
324 * First check cmdline, then dmi quirks, then do autodetect.
326 * The autodetect order is:
327 * 1) Is the acpi-video backlight interface supported ->
328 * no, use a vendor interface
329 * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
330 * yes, use a native interface
331 * 3) Else use the acpi-video interface
333 * Arguably the native on win8 check should be done first, but that would
334 * be a behavior change, which may causes issues.
336 enum acpi_backlight_type acpi_video_get_backlight_type(void)
338 static DEFINE_MUTEX(init_mutex);
339 static bool init_done;
340 static long video_caps;
342 /* Parse cmdline, dmi and acpi only once */
343 mutex_lock(&init_mutex);
345 acpi_video_parse_cmdline();
346 dmi_check_system(video_detect_dmi_table);
347 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
348 ACPI_UINT32_MAX, find_video, NULL,
350 INIT_WORK(&backlight_notify_work,
351 acpi_video_backlight_notify_work);
352 backlight_nb.notifier_call = acpi_video_backlight_notify;
353 backlight_nb.priority = 0;
354 if (backlight_register_notifier(&backlight_nb) == 0)
355 backlight_notifier_registered = true;
358 mutex_unlock(&init_mutex);
360 if (acpi_backlight_cmdline != acpi_backlight_undef)
361 return acpi_backlight_cmdline;
363 if (acpi_backlight_dmi != acpi_backlight_undef)
364 return acpi_backlight_dmi;
366 if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
367 return acpi_backlight_vendor;
369 if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW))
370 return acpi_backlight_native;
372 return acpi_backlight_video;
374 EXPORT_SYMBOL(acpi_video_get_backlight_type);
377 * Set the preferred backlight interface type based on DMI info.
378 * This function allows DMI blacklists to be implemented by external
379 * platform drivers instead of putting a big blacklist in video_detect.c
381 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
383 acpi_backlight_dmi = type;
384 /* Remove acpi-video backlight interface if it is no longer desired */
385 if (acpi_video_get_backlight_type() != acpi_backlight_video)
386 acpi_video_unregister_backlight();
388 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
390 void __exit acpi_video_detect_exit(void)
392 if (backlight_notifier_registered)
393 backlight_unregister_notifier(&backlight_nb);