1 /*
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>
6  *
7  *  May be copied or modified under the terms of the GNU General Public License
8  *
9  * video_detect.c:
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
13  *
14  * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
15  * are available, video.ko should be used to handle the device.
16  *
17  * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
18  * sony_acpi,... can take care about backlight brightness.
19  *
20  * Backlight drivers can use acpi_video_get_backlight_type() to determine
21  * which driver should handle the backlight.
22  *
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.
26  */
27 
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>
37 
38 ACPI_MODULE_NAME("video");
39 #define _COMPONENT		ACPI_VIDEO_COMPONENT
40 
41 void acpi_video_unregister_backlight(void);
42 
43 static bool backlight_notifier_registered;
44 static struct notifier_block backlight_nb;
45 static struct work_struct backlight_notify_work;
46 
47 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
48 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
49 
acpi_video_parse_cmdline(void)50 static void acpi_video_parse_cmdline(void)
51 {
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;
60 }
61 
62 static acpi_status
find_video(acpi_handle handle,u32 lvl,void * context,void ** rv)63 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
64 {
65 	long *cap = context;
66 	struct pci_dev *dev;
67 	struct acpi_device *acpi_dev;
68 
69 	static const struct acpi_device_id video_ids[] = {
70 		{ACPI_VIDEO_HID, 0},
71 		{"", 0},
72 	};
73 	if (acpi_bus_get_device(handle, &acpi_dev))
74 		return AE_OK;
75 
76 	if (!acpi_match_device_ids(acpi_dev, video_ids)) {
77 		dev = acpi_get_pci_dev(handle);
78 		if (!dev)
79 			return AE_OK;
80 		pci_dev_put(dev);
81 		*cap |= acpi_is_video_device(handle);
82 	}
83 	return AE_OK;
84 }
85 
86 /* Force to use vendor driver when the ACPI device is known to be
87  * buggy */
video_detect_force_vendor(const struct dmi_system_id * d)88 static int video_detect_force_vendor(const struct dmi_system_id *d)
89 {
90 	acpi_backlight_dmi = acpi_backlight_vendor;
91 	return 0;
92 }
93 
video_detect_force_video(const struct dmi_system_id * d)94 static int video_detect_force_video(const struct dmi_system_id *d)
95 {
96 	acpi_backlight_dmi = acpi_backlight_video;
97 	return 0;
98 }
99 
video_detect_force_native(const struct dmi_system_id * d)100 static int video_detect_force_native(const struct dmi_system_id *d)
101 {
102 	acpi_backlight_dmi = acpi_backlight_native;
103 	return 0;
104 }
105 
video_detect_force_none(const struct dmi_system_id * d)106 static int video_detect_force_none(const struct dmi_system_id *d)
107 {
108 	acpi_backlight_dmi = acpi_backlight_none;
109 	return 0;
110 }
111 
112 static const struct dmi_system_id video_detect_dmi_table[] = {
113 	/* On Samsung X360, the BIOS will set a flag (VDRV) if generic
114 	 * ACPI backlight device is used. This flag will definitively break
115 	 * the backlight interface (even the vendor interface) until next
116 	 * reboot. It's why we should prevent video.ko from being used here
117 	 * and we can't rely on a later call to acpi_video_unregister().
118 	 */
119 	{
120 	 .callback = video_detect_force_vendor,
121 	 .ident = "X360",
122 	 .matches = {
123 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
124 		DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
125 		DMI_MATCH(DMI_BOARD_NAME, "X360"),
126 		},
127 	},
128 	{
129 	.callback = video_detect_force_vendor,
130 	.ident = "Asus UL30VT",
131 	.matches = {
132 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
133 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
134 		},
135 	},
136 	{
137 	.callback = video_detect_force_vendor,
138 	.ident = "Asus UL30A",
139 	.matches = {
140 		DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
141 		DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
142 		},
143 	},
144 	{
145 	.callback = video_detect_force_vendor,
146 	.ident = "Sony VPCEH3U1E",
147 	.matches = {
148 		DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
149 		DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
150 		},
151 	},
152 
153 	/*
154 	 * These models have a working acpi_video backlight control, and using
155 	 * native backlight causes a regression where backlight does not work
156 	 * when userspace is not handling brightness key events. Disable
157 	 * native_backlight on these to fix this:
158 	 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
159 	 */
160 	{
161 	 .callback = video_detect_force_video,
162 	 .ident = "ThinkPad T420",
163 	 .matches = {
164 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
165 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
166 		},
167 	},
168 	{
169 	 .callback = video_detect_force_video,
170 	 .ident = "ThinkPad T520",
171 	 .matches = {
172 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
173 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
174 		},
175 	},
176 	{
177 	 .callback = video_detect_force_video,
178 	 .ident = "ThinkPad X201s",
179 	 .matches = {
180 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
181 		DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
182 		},
183 	},
184         {
185          .callback = video_detect_force_video,
186          .ident = "ThinkPad X201T",
187          .matches = {
188                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
189                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
190                 },
191         },
192 
193 	/* The native backlight controls do not work on some older machines */
194 	{
195 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
196 	 .callback = video_detect_force_video,
197 	 .ident = "HP ENVY 15 Notebook",
198 	 .matches = {
199 		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
200 		DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
201 		},
202 	},
203 	{
204 	 .callback = video_detect_force_video,
205 	 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
206 	 .matches = {
207 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
208 		DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
209 		},
210 	},
211 	{
212 	 .callback = video_detect_force_video,
213 	 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
214 	 .matches = {
215 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
216 		DMI_MATCH(DMI_PRODUCT_NAME,
217 			  "370R4E/370R4V/370R5E/3570RE/370R5V"),
218 		},
219 	},
220 	{
221 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
222 	 .callback = video_detect_force_video,
223 	 .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
224 	 .matches = {
225 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
226 		DMI_MATCH(DMI_PRODUCT_NAME,
227 			  "3570R/370R/470R/450R/510R/4450RV"),
228 		},
229 	},
230 	{
231 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
232 	 .callback = video_detect_force_video,
233 	 .ident = "SAMSUNG 670Z5E",
234 	 .matches = {
235 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
236 		DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
237 		},
238 	},
239 	{
240 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
241 	 .callback = video_detect_force_video,
242 	 .ident = "SAMSUNG 730U3E/740U3E",
243 	 .matches = {
244 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
245 		DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
246 		},
247 	},
248 	{
249 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
250 	 .callback = video_detect_force_video,
251 	 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
252 	 .matches = {
253 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
254 		DMI_MATCH(DMI_PRODUCT_NAME,
255 			  "900X3C/900X3D/900X3E/900X4C/900X4D"),
256 		},
257 	},
258 	{
259 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
260 	 .callback = video_detect_force_video,
261 	 .ident = "Dell XPS14 L421X",
262 	 .matches = {
263 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
264 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
265 		},
266 	},
267 	{
268 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
269 	 .callback = video_detect_force_video,
270 	 .ident = "Dell XPS15 L521X",
271 	 .matches = {
272 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
273 		DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
274 		},
275 	},
276 	{
277 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
278 	 .callback = video_detect_force_video,
279 	 .ident = "SAMSUNG 530U4E/540U4E",
280 	 .matches = {
281 		DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
282 		DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
283 		},
284 	},
285 
286 	/* Non win8 machines which need native backlight nevertheless */
287 	{
288 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
289 	 .callback = video_detect_force_native,
290 	 .ident = "Lenovo Ideapad S405",
291 	 .matches = {
292 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
293 		DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
294 		},
295 	},
296 	{
297 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
298 	 .callback = video_detect_force_native,
299 	 .ident = "Lenovo Ideapad Z570",
300 	 .matches = {
301 		DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
302 		DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
303 		},
304 	},
305 	{
306 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
307 	 .callback = video_detect_force_native,
308 	 .ident = "Apple MacBook Pro 12,1",
309 	 .matches = {
310 		DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
311 		DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
312 		},
313 	},
314 	{
315 	 .callback = video_detect_force_native,
316 	 .ident = "Dell Vostro V131",
317 	 .matches = {
318 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
319 		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
320 		},
321 	},
322 	{
323 	 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
324 	 .callback = video_detect_force_native,
325 	 .ident = "Dell XPS 17 L702X",
326 	 .matches = {
327 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
328 		DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
329 		},
330 	},
331 	{
332 	 .callback = video_detect_force_native,
333 	 .ident = "Dell Precision 7510",
334 	 .matches = {
335 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
336 		DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
337 		},
338 	},
339 	{
340 	 .callback = video_detect_force_none,
341 	 .ident = "Dell OptiPlex 9020M",
342 	 .matches = {
343 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
344 		DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 9020M"),
345 		},
346 	},
347 	{ },
348 };
349 
350 /* This uses a workqueue to avoid various locking ordering issues */
acpi_video_backlight_notify_work(struct work_struct * work)351 static void acpi_video_backlight_notify_work(struct work_struct *work)
352 {
353 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
354 		acpi_video_unregister_backlight();
355 }
356 
acpi_video_backlight_notify(struct notifier_block * nb,unsigned long val,void * bd)357 static int acpi_video_backlight_notify(struct notifier_block *nb,
358 				       unsigned long val, void *bd)
359 {
360 	struct backlight_device *backlight = bd;
361 
362 	/* A raw bl registering may change video -> native */
363 	if (backlight->props.type == BACKLIGHT_RAW &&
364 	    val == BACKLIGHT_REGISTERED)
365 		schedule_work(&backlight_notify_work);
366 
367 	return NOTIFY_OK;
368 }
369 
370 /*
371  * Determine which type of backlight interface to use on this system,
372  * First check cmdline, then dmi quirks, then do autodetect.
373  *
374  * The autodetect order is:
375  * 1) Is the acpi-video backlight interface supported ->
376  *  no, use a vendor interface
377  * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
378  *  yes, use a native interface
379  * 3) Else use the acpi-video interface
380  *
381  * Arguably the native on win8 check should be done first, but that would
382  * be a behavior change, which may causes issues.
383  */
acpi_video_get_backlight_type(void)384 enum acpi_backlight_type acpi_video_get_backlight_type(void)
385 {
386 	static DEFINE_MUTEX(init_mutex);
387 	static bool init_done;
388 	static long video_caps;
389 
390 	/* Parse cmdline, dmi and acpi only once */
391 	mutex_lock(&init_mutex);
392 	if (!init_done) {
393 		acpi_video_parse_cmdline();
394 		dmi_check_system(video_detect_dmi_table);
395 		acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
396 				    ACPI_UINT32_MAX, find_video, NULL,
397 				    &video_caps, NULL);
398 		INIT_WORK(&backlight_notify_work,
399 			  acpi_video_backlight_notify_work);
400 		backlight_nb.notifier_call = acpi_video_backlight_notify;
401 		backlight_nb.priority = 0;
402 		if (backlight_register_notifier(&backlight_nb) == 0)
403 			backlight_notifier_registered = true;
404 		init_done = true;
405 	}
406 	mutex_unlock(&init_mutex);
407 
408 	if (acpi_backlight_cmdline != acpi_backlight_undef)
409 		return acpi_backlight_cmdline;
410 
411 	if (acpi_backlight_dmi != acpi_backlight_undef)
412 		return acpi_backlight_dmi;
413 
414 	if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
415 		return acpi_backlight_vendor;
416 
417 	if (acpi_osi_is_win8() && backlight_device_get_by_type(BACKLIGHT_RAW))
418 		return acpi_backlight_native;
419 
420 	return acpi_backlight_video;
421 }
422 EXPORT_SYMBOL(acpi_video_get_backlight_type);
423 
424 /*
425  * Set the preferred backlight interface type based on DMI info.
426  * This function allows DMI blacklists to be implemented by external
427  * platform drivers instead of putting a big blacklist in video_detect.c
428  */
acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)429 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
430 {
431 	acpi_backlight_dmi = type;
432 	/* Remove acpi-video backlight interface if it is no longer desired */
433 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
434 		acpi_video_unregister_backlight();
435 }
436 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
437 
acpi_video_detect_exit(void)438 void __exit acpi_video_detect_exit(void)
439 {
440 	if (backlight_notifier_registered)
441 		backlight_unregister_notifier(&backlight_nb);
442 }
443