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"),
139 .callback
= video_detect_force_vendor
,
140 .ident
= "Dell Inspiron 5737",
142 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Inc."),
143 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron 5737"),
148 * These models have a working acpi_video backlight control, and using
149 * native backlight causes a regression where backlight does not work
150 * when userspace is not handling brightness key events. Disable
151 * native_backlight on these to fix this:
152 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
155 .callback
= video_detect_force_video
,
156 .ident
= "ThinkPad T420",
158 DMI_MATCH(DMI_SYS_VENDOR
, "LENOVO"),
159 DMI_MATCH(DMI_PRODUCT_VERSION
, "ThinkPad T420"),
163 .callback
= video_detect_force_video
,
164 .ident
= "ThinkPad T520",
166 DMI_MATCH(DMI_SYS_VENDOR
, "LENOVO"),
167 DMI_MATCH(DMI_PRODUCT_VERSION
, "ThinkPad T520"),
171 .callback
= video_detect_force_video
,
172 .ident
= "ThinkPad X201s",
174 DMI_MATCH(DMI_SYS_VENDOR
, "LENOVO"),
175 DMI_MATCH(DMI_PRODUCT_VERSION
, "ThinkPad X201s"),
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 /* Non win8 machines which need native backlight nevertheless */
256 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
257 .callback
= video_detect_force_native
,
258 .ident
= "Lenovo Ideapad S405",
260 DMI_MATCH(DMI_SYS_VENDOR
, "LENOVO"),
261 DMI_MATCH(DMI_BOARD_NAME
, "Lenovo IdeaPad S405"),
265 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
266 .callback
= video_detect_force_native
,
267 .ident
= "Lenovo Ideapad Z570",
269 DMI_MATCH(DMI_SYS_VENDOR
, "LENOVO"),
270 DMI_MATCH(DMI_PRODUCT_NAME
, "102434U"),
274 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
275 .callback
= video_detect_force_native
,
276 .ident
= "Apple MacBook Pro 12,1",
278 DMI_MATCH(DMI_SYS_VENDOR
, "Apple Inc."),
279 DMI_MATCH(DMI_PRODUCT_NAME
, "MacBookPro12,1"),
285 /* This uses a workqueue to avoid various locking ordering issues */
286 static void acpi_video_backlight_notify_work(struct work_struct
*work
)
288 if (acpi_video_get_backlight_type() != acpi_backlight_video
)
289 acpi_video_unregister_backlight();
292 static int acpi_video_backlight_notify(struct notifier_block
*nb
,
293 unsigned long val
, void *bd
)
295 struct backlight_device
*backlight
= bd
;
297 /* A raw bl registering may change video -> native */
298 if (backlight
->props
.type
== BACKLIGHT_RAW
&&
299 val
== BACKLIGHT_REGISTERED
)
300 schedule_work(&backlight_notify_work
);
306 * Determine which type of backlight interface to use on this system,
307 * First check cmdline, then dmi quirks, then do autodetect.
309 * The autodetect order is:
310 * 1) Is the acpi-video backlight interface supported ->
311 * no, use a vendor interface
312 * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
313 * yes, use a native interface
314 * 3) Else use the acpi-video interface
316 * Arguably the native on win8 check should be done first, but that would
317 * be a behavior change, which may causes issues.
319 enum acpi_backlight_type
acpi_video_get_backlight_type(void)
321 static DEFINE_MUTEX(init_mutex
);
322 static bool init_done
;
323 static long video_caps
;
325 /* Parse cmdline, dmi and acpi only once */
326 mutex_lock(&init_mutex
);
328 acpi_video_parse_cmdline();
329 dmi_check_system(video_detect_dmi_table
);
330 acpi_walk_namespace(ACPI_TYPE_DEVICE
, ACPI_ROOT_OBJECT
,
331 ACPI_UINT32_MAX
, find_video
, NULL
,
333 INIT_WORK(&backlight_notify_work
,
334 acpi_video_backlight_notify_work
);
335 backlight_nb
.notifier_call
= acpi_video_backlight_notify
;
336 backlight_nb
.priority
= 0;
337 if (backlight_register_notifier(&backlight_nb
) == 0)
338 backlight_notifier_registered
= true;
341 mutex_unlock(&init_mutex
);
343 if (acpi_backlight_cmdline
!= acpi_backlight_undef
)
344 return acpi_backlight_cmdline
;
346 if (acpi_backlight_dmi
!= acpi_backlight_undef
)
347 return acpi_backlight_dmi
;
349 if (!(video_caps
& ACPI_VIDEO_BACKLIGHT
))
350 return acpi_backlight_vendor
;
352 if (acpi_osi_is_win8() && backlight_device_registered(BACKLIGHT_RAW
))
353 return acpi_backlight_native
;
355 return acpi_backlight_video
;
357 EXPORT_SYMBOL(acpi_video_get_backlight_type
);
360 * Set the preferred backlight interface type based on DMI info.
361 * This function allows DMI blacklists to be implemented by external
362 * platform drivers instead of putting a big blacklist in video_detect.c
364 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type
)
366 acpi_backlight_dmi
= type
;
367 /* Remove acpi-video backlight interface if it is no longer desired */
368 if (acpi_video_get_backlight_type() != acpi_backlight_video
)
369 acpi_video_unregister_backlight();
371 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type
);
373 void __exit
acpi_video_detect_exit(void)
375 if (backlight_notifier_registered
)
376 backlight_unregister_notifier(&backlight_nb
);