Loading...
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
43ACPI_MODULE_NAME("video");
44#define _COMPONENT ACPI_VIDEO_COMPONENT
45
46static long acpi_video_support;
47static bool acpi_video_caps_checked;
48
49static acpi_status
50acpi_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 device is a video device which can be handled by
71 * 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 */
78long acpi_is_video_device(struct acpi_device *device)
79{
80 acpi_handle h_dummy;
81 long video_caps = 0;
82
83 if (!device)
84 return 0;
85
86 /* Is this device able to support video switching ? */
87 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOD", &h_dummy)) ||
88 ACPI_SUCCESS(acpi_get_handle(device->handle, "_DOS", &h_dummy)))
89 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
90
91 /* Is this device able to retrieve a video ROM ? */
92 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_ROM", &h_dummy)))
93 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
94
95 /* Is this device able to configure which video head to be POSTed ? */
96 if (ACPI_SUCCESS(acpi_get_handle(device->handle, "_VPO", &h_dummy)) &&
97 ACPI_SUCCESS(acpi_get_handle(device->handle, "_GPD", &h_dummy)) &&
98 ACPI_SUCCESS(acpi_get_handle(device->handle, "_SPD", &h_dummy)))
99 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
100
101 /* Only check for backlight functionality if one of the above hit. */
102 if (video_caps)
103 acpi_walk_namespace(ACPI_TYPE_DEVICE, device->handle,
104 ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
105 &video_caps, NULL);
106
107 return video_caps;
108}
109EXPORT_SYMBOL(acpi_is_video_device);
110
111static acpi_status
112find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
113{
114 long *cap = context;
115 struct pci_dev *dev;
116 struct acpi_device *acpi_dev;
117
118 const struct acpi_device_id video_ids[] = {
119 {ACPI_VIDEO_HID, 0},
120 {"", 0},
121 };
122 if (acpi_bus_get_device(handle, &acpi_dev))
123 return AE_OK;
124
125 if (!acpi_match_device_ids(acpi_dev, video_ids)) {
126 dev = acpi_get_pci_dev(handle);
127 if (!dev)
128 return AE_OK;
129 pci_dev_put(dev);
130 *cap |= acpi_is_video_device(acpi_dev);
131 }
132 return AE_OK;
133}
134
135/*
136 * Returns the video capabilities of a specific ACPI graphics device
137 *
138 * if NULL is passed as argument all ACPI devices are enumerated and
139 * all graphics capabilities of physically present devices are
140 * summarized and returned. This is cached and done only once.
141 */
142long acpi_video_get_capabilities(acpi_handle graphics_handle)
143{
144 long caps = 0;
145 struct acpi_device *tmp_dev;
146 acpi_status status;
147
148 if (acpi_video_caps_checked && graphics_handle == NULL)
149 return acpi_video_support;
150
151 if (!graphics_handle) {
152 /* Only do the global walk through all graphics devices once */
153 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
154 ACPI_UINT32_MAX, find_video, NULL,
155 &caps, NULL);
156 /* There might be boot param flags set already... */
157 acpi_video_support |= caps;
158 acpi_video_caps_checked = 1;
159 /* Add blacklists here. Be careful to use the right *DMI* bits
160 * to still be able to override logic via boot params, e.g.:
161 *
162 * if (dmi_name_in_vendors("XY")) {
163 * acpi_video_support |=
164 * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
165 *}
166 */
167 } else {
168 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
169 if (ACPI_FAILURE(status)) {
170 ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
171 return 0;
172 }
173 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
174 ACPI_UINT32_MAX, find_video, NULL,
175 &caps, NULL);
176 }
177 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
178 graphics_handle ? caps : acpi_video_support,
179 graphics_handle ? "on device " : "in general",
180 graphics_handle ? acpi_device_bid(tmp_dev) : ""));
181 return caps;
182}
183EXPORT_SYMBOL(acpi_video_get_capabilities);
184
185/* Returns true if video.ko can do backlight switching */
186int acpi_video_backlight_support(void)
187{
188 /*
189 * We must check whether the ACPI graphics device is physically plugged
190 * in. Therefore this must be called after binding PCI and ACPI devices
191 */
192 if (!acpi_video_caps_checked)
193 acpi_video_get_capabilities(NULL);
194
195 /* First check for boot param -> highest prio */
196 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
197 return 0;
198 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
199 return 1;
200
201 /* Then check for DMI blacklist -> second highest prio */
202 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
203 return 0;
204 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
205 return 1;
206
207 /* Then go the default way */
208 return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
209}
210EXPORT_SYMBOL(acpi_video_backlight_support);
211
212/*
213 * Use acpi_backlight=vendor/video to force that backlight switching
214 * is processed by vendor specific acpi drivers or video.ko driver.
215 */
216static int __init acpi_backlight(char *str)
217{
218 if (str == NULL || *str == '\0')
219 return 1;
220 else {
221 if (!strcmp("vendor", str))
222 acpi_video_support |=
223 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
224 if (!strcmp("video", str))
225 acpi_video_support |=
226 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
227 }
228 return 1;
229}
230__setup("acpi_backlight=", acpi_backlight);
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 which
21 * driver should handle the backlight. RAW/GPU-driver backlight drivers must
22 * use the acpi_video_backlight_use_native() helper for this.
23 *
24 * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
25 * this file will not be compiled and acpi_video_get_backlight_type() will
26 * always return acpi_backlight_vendor.
27 */
28
29#include <linux/export.h>
30#include <linux/acpi.h>
31#include <linux/apple-gmux.h>
32#include <linux/backlight.h>
33#include <linux/dmi.h>
34#include <linux/module.h>
35#include <linux/pci.h>
36#include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h>
37#include <linux/pnp.h>
38#include <linux/types.h>
39#include <linux/workqueue.h>
40#include <acpi/video.h>
41
42static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
43static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
44
45static void acpi_video_parse_cmdline(void)
46{
47 if (!strcmp("vendor", acpi_video_backlight_string))
48 acpi_backlight_cmdline = acpi_backlight_vendor;
49 if (!strcmp("video", acpi_video_backlight_string))
50 acpi_backlight_cmdline = acpi_backlight_video;
51 if (!strcmp("native", acpi_video_backlight_string))
52 acpi_backlight_cmdline = acpi_backlight_native;
53 if (!strcmp("nvidia_wmi_ec", acpi_video_backlight_string))
54 acpi_backlight_cmdline = acpi_backlight_nvidia_wmi_ec;
55 if (!strcmp("apple_gmux", acpi_video_backlight_string))
56 acpi_backlight_cmdline = acpi_backlight_apple_gmux;
57 if (!strcmp("dell_uart", acpi_video_backlight_string))
58 acpi_backlight_cmdline = acpi_backlight_dell_uart;
59 if (!strcmp("none", acpi_video_backlight_string))
60 acpi_backlight_cmdline = acpi_backlight_none;
61}
62
63static acpi_status
64find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
65{
66 struct acpi_device *acpi_dev = acpi_fetch_acpi_dev(handle);
67 long *cap = context;
68 struct pci_dev *dev;
69
70 static const struct acpi_device_id video_ids[] = {
71 {ACPI_VIDEO_HID, 0},
72 {"", 0},
73 };
74
75 if (acpi_dev && !acpi_match_device_ids(acpi_dev, video_ids)) {
76 dev = acpi_get_pci_dev(handle);
77 if (!dev)
78 return AE_OK;
79 pci_dev_put(dev);
80 *cap |= acpi_is_video_device(handle);
81 }
82 return AE_OK;
83}
84
85/* This depends on ACPI_WMI which is X86 only */
86#ifdef CONFIG_X86
87static bool nvidia_wmi_ec_supported(void)
88{
89 struct wmi_brightness_args args = {
90 .mode = WMI_BRIGHTNESS_MODE_GET,
91 .val = 0,
92 .ret = 0,
93 };
94 struct acpi_buffer buf = { (acpi_size)sizeof(args), &args };
95 acpi_status status;
96
97 status = wmi_evaluate_method(WMI_BRIGHTNESS_GUID, 0,
98 WMI_BRIGHTNESS_METHOD_SOURCE, &buf, &buf);
99 if (ACPI_FAILURE(status))
100 return false;
101
102 /*
103 * If brightness is handled by the EC then nvidia-wmi-ec-backlight
104 * should be used, else the GPU driver(s) should be used.
105 */
106 return args.ret == WMI_BRIGHTNESS_SOURCE_EC;
107}
108#else
109static bool nvidia_wmi_ec_supported(void)
110{
111 return false;
112}
113#endif
114
115/* Force to use vendor driver when the ACPI device is known to be
116 * buggy */
117static int video_detect_force_vendor(const struct dmi_system_id *d)
118{
119 acpi_backlight_dmi = acpi_backlight_vendor;
120 return 0;
121}
122
123static int video_detect_force_video(const struct dmi_system_id *d)
124{
125 acpi_backlight_dmi = acpi_backlight_video;
126 return 0;
127}
128
129static int video_detect_force_native(const struct dmi_system_id *d)
130{
131 acpi_backlight_dmi = acpi_backlight_native;
132 return 0;
133}
134
135static int video_detect_portege_r100(const struct dmi_system_id *d)
136{
137 struct pci_dev *dev;
138 /* Search for Trident CyberBlade XP4m32 to confirm Portégé R100 */
139 dev = pci_get_device(PCI_VENDOR_ID_TRIDENT, 0x2100, NULL);
140 if (dev)
141 acpi_backlight_dmi = acpi_backlight_vendor;
142 return 0;
143}
144
145static const struct dmi_system_id video_detect_dmi_table[] = {
146 /*
147 * Models which should use the vendor backlight interface,
148 * because of broken ACPI video backlight control.
149 */
150 {
151 /* https://bugzilla.redhat.com/show_bug.cgi?id=1128309 */
152 .callback = video_detect_force_vendor,
153 /* Acer KAV80 */
154 .matches = {
155 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
156 DMI_MATCH(DMI_PRODUCT_NAME, "KAV80"),
157 },
158 },
159 {
160 .callback = video_detect_force_vendor,
161 /* Asus UL30VT */
162 .matches = {
163 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
164 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
165 },
166 },
167 {
168 .callback = video_detect_force_vendor,
169 /* Asus UL30A */
170 .matches = {
171 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
172 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
173 },
174 },
175 {
176 .callback = video_detect_force_vendor,
177 /* Asus X55U */
178 .matches = {
179 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
180 DMI_MATCH(DMI_PRODUCT_NAME, "X55U"),
181 },
182 },
183 {
184 /* https://bugs.launchpad.net/bugs/1000146 */
185 .callback = video_detect_force_vendor,
186 /* Asus X101CH */
187 .matches = {
188 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
189 DMI_MATCH(DMI_PRODUCT_NAME, "X101CH"),
190 },
191 },
192 {
193 .callback = video_detect_force_vendor,
194 /* Asus X401U */
195 .matches = {
196 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
197 DMI_MATCH(DMI_PRODUCT_NAME, "X401U"),
198 },
199 },
200 {
201 .callback = video_detect_force_vendor,
202 /* Asus X501U */
203 .matches = {
204 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
205 DMI_MATCH(DMI_PRODUCT_NAME, "X501U"),
206 },
207 },
208 {
209 /* https://bugs.launchpad.net/bugs/1000146 */
210 .callback = video_detect_force_vendor,
211 /* Asus 1015CX */
212 .matches = {
213 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
214 DMI_MATCH(DMI_PRODUCT_NAME, "1015CX"),
215 },
216 },
217 {
218 .callback = video_detect_force_vendor,
219 /* Samsung N150/N210/N220 */
220 .matches = {
221 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
222 DMI_MATCH(DMI_PRODUCT_NAME, "N150/N210/N220"),
223 DMI_MATCH(DMI_BOARD_NAME, "N150/N210/N220"),
224 },
225 },
226 {
227 .callback = video_detect_force_vendor,
228 /* Samsung NF110/NF210/NF310 */
229 .matches = {
230 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
231 DMI_MATCH(DMI_PRODUCT_NAME, "NF110/NF210/NF310"),
232 DMI_MATCH(DMI_BOARD_NAME, "NF110/NF210/NF310"),
233 },
234 },
235 {
236 .callback = video_detect_force_vendor,
237 /* Samsung NC210 */
238 .matches = {
239 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
240 DMI_MATCH(DMI_PRODUCT_NAME, "NC210/NC110"),
241 DMI_MATCH(DMI_BOARD_NAME, "NC210/NC110"),
242 },
243 },
244
245 /*
246 * Models which should use the vendor backlight interface,
247 * because of broken native backlight control.
248 */
249 {
250 .callback = video_detect_force_vendor,
251 /* Sony Vaio PCG-FRV35 */
252 .matches = {
253 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
254 DMI_MATCH(DMI_PRODUCT_NAME, "PCG-FRV35"),
255 },
256 },
257 {
258 .callback = video_detect_force_vendor,
259 /* Panasonic Toughbook CF-18 */
260 .matches = {
261 DMI_MATCH(DMI_SYS_VENDOR, "Matsushita Electric Industrial"),
262 DMI_MATCH(DMI_PRODUCT_NAME, "CF-18"),
263 },
264 },
265
266 /*
267 * Toshiba models with Transflective display, these need to use
268 * the toshiba_acpi vendor driver for proper Transflective handling.
269 */
270 {
271 .callback = video_detect_force_vendor,
272 .matches = {
273 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
274 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R500"),
275 },
276 },
277 {
278 .callback = video_detect_force_vendor,
279 .matches = {
280 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
281 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R600"),
282 },
283 },
284
285 /*
286 * Toshiba Portégé R100 has working both acpi_video and toshiba_acpi
287 * vendor driver. But none of them gets activated as it has a VGA with
288 * no kernel driver (Trident CyberBlade XP4m32).
289 * The DMI strings are generic so check for the VGA chip in callback.
290 */
291 {
292 .callback = video_detect_portege_r100,
293 .matches = {
294 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
295 DMI_MATCH(DMI_PRODUCT_NAME, "Portable PC"),
296 DMI_MATCH(DMI_PRODUCT_VERSION, "Version 1.0"),
297 DMI_MATCH(DMI_BOARD_NAME, "Portable PC")
298 },
299 },
300
301 /*
302 * Models which need acpi_video backlight control where the GPU drivers
303 * do not call acpi_video_register_backlight() because no internal panel
304 * is detected. Typically these are all-in-ones (monitors with builtin
305 * PC) where the panel connection shows up as regular DP instead of eDP.
306 */
307 {
308 .callback = video_detect_force_video,
309 /* Apple iMac14,1 */
310 .matches = {
311 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
312 DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,1"),
313 },
314 },
315 {
316 .callback = video_detect_force_video,
317 /* Apple iMac14,2 */
318 .matches = {
319 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
320 DMI_MATCH(DMI_PRODUCT_NAME, "iMac14,2"),
321 },
322 },
323
324 /*
325 * These models have a working acpi_video backlight control, and using
326 * native backlight causes a regression where backlight does not work
327 * when userspace is not handling brightness key events. Disable
328 * native_backlight on these to fix this:
329 * https://bugzilla.kernel.org/show_bug.cgi?id=81691
330 */
331 {
332 .callback = video_detect_force_video,
333 /* ThinkPad T420 */
334 .matches = {
335 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
336 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
337 },
338 },
339 {
340 .callback = video_detect_force_video,
341 /* ThinkPad T520 */
342 .matches = {
343 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
344 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
345 },
346 },
347 {
348 .callback = video_detect_force_video,
349 /* ThinkPad X201s */
350 .matches = {
351 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
352 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
353 },
354 },
355 {
356 .callback = video_detect_force_video,
357 /* ThinkPad X201T */
358 .matches = {
359 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
360 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201T"),
361 },
362 },
363
364 /* The native backlight controls do not work on some older machines */
365 {
366 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
367 .callback = video_detect_force_video,
368 /* HP ENVY 15 Notebook */
369 .matches = {
370 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
371 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
372 },
373 },
374 {
375 .callback = video_detect_force_video,
376 /* SAMSUNG 870Z5E/880Z5E/680Z5E */
377 .matches = {
378 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
379 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
380 },
381 },
382 {
383 .callback = video_detect_force_video,
384 /* SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V */
385 .matches = {
386 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
387 DMI_MATCH(DMI_PRODUCT_NAME,
388 "370R4E/370R4V/370R5E/3570RE/370R5V"),
389 },
390 },
391 {
392 /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
393 .callback = video_detect_force_video,
394 /* SAMSUNG 3570R/370R/470R/450R/510R/4450RV */
395 .matches = {
396 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
397 DMI_MATCH(DMI_PRODUCT_NAME,
398 "3570R/370R/470R/450R/510R/4450RV"),
399 },
400 },
401 {
402 /* https://bugzilla.redhat.com/show_bug.cgi?id=1557060 */
403 .callback = video_detect_force_video,
404 /* SAMSUNG 670Z5E */
405 .matches = {
406 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
407 DMI_MATCH(DMI_PRODUCT_NAME, "670Z5E"),
408 },
409 },
410 {
411 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
412 .callback = video_detect_force_video,
413 /* SAMSUNG 730U3E/740U3E */
414 .matches = {
415 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
416 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
417 },
418 },
419 {
420 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
421 .callback = video_detect_force_video,
422 /* SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D */
423 .matches = {
424 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
425 DMI_MATCH(DMI_PRODUCT_NAME,
426 "900X3C/900X3D/900X3E/900X4C/900X4D"),
427 },
428 },
429 {
430 /* https://bugzilla.redhat.com/show_bug.cgi?id=1272633 */
431 .callback = video_detect_force_video,
432 /* Dell XPS14 L421X */
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
435 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L421X"),
436 },
437 },
438 {
439 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
440 .callback = video_detect_force_video,
441 /* Dell XPS15 L521X */
442 .matches = {
443 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
444 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
445 },
446 },
447 {
448 /* https://bugzilla.kernel.org/show_bug.cgi?id=108971 */
449 .callback = video_detect_force_video,
450 /* SAMSUNG 530U4E/540U4E */
451 .matches = {
452 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
453 DMI_MATCH(DMI_PRODUCT_NAME, "530U4E/540U4E"),
454 },
455 },
456 {
457 /* https://bugs.launchpad.net/bugs/1894667 */
458 .callback = video_detect_force_video,
459 /* HP 635 Notebook */
460 .matches = {
461 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
462 DMI_MATCH(DMI_PRODUCT_NAME, "HP 635 Notebook PC"),
463 },
464 },
465
466 /* Non win8 machines which need native backlight nevertheless */
467 {
468 /* https://bugzilla.redhat.com/show_bug.cgi?id=1201530 */
469 .callback = video_detect_force_native,
470 /* Lenovo Ideapad S405 */
471 .matches = {
472 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
473 DMI_MATCH(DMI_BOARD_NAME, "Lenovo IdeaPad S405"),
474 },
475 },
476 {
477 /* https://bugzilla.suse.com/show_bug.cgi?id=1208724 */
478 .callback = video_detect_force_native,
479 /* Lenovo Ideapad Z470 */
480 .matches = {
481 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
482 DMI_MATCH(DMI_PRODUCT_VERSION, "IdeaPad Z470"),
483 },
484 },
485 {
486 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
487 .callback = video_detect_force_native,
488 /* Lenovo Ideapad Z570 */
489 .matches = {
490 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
491 DMI_MATCH(DMI_PRODUCT_VERSION, "Ideapad Z570"),
492 },
493 },
494 {
495 .callback = video_detect_force_native,
496 /* Lenovo E41-25 */
497 .matches = {
498 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
499 DMI_MATCH(DMI_PRODUCT_NAME, "81FS"),
500 },
501 },
502 {
503 .callback = video_detect_force_native,
504 /* Lenovo E41-45 */
505 .matches = {
506 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
507 DMI_MATCH(DMI_PRODUCT_NAME, "82BK"),
508 },
509 },
510 {
511 .callback = video_detect_force_native,
512 /* Lenovo Slim 7 16ARH7 */
513 .matches = {
514 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
515 DMI_MATCH(DMI_PRODUCT_NAME, "82UX"),
516 },
517 },
518 {
519 .callback = video_detect_force_native,
520 /* Lenovo ThinkPad X131e (3371 AMD version) */
521 .matches = {
522 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
523 DMI_MATCH(DMI_PRODUCT_NAME, "3371"),
524 },
525 },
526 {
527 .callback = video_detect_force_native,
528 /* Apple iMac11,3 */
529 .matches = {
530 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
531 DMI_MATCH(DMI_PRODUCT_NAME, "iMac11,3"),
532 },
533 },
534 {
535 /* https://gitlab.freedesktop.org/drm/amd/-/issues/1838 */
536 .callback = video_detect_force_native,
537 /* Apple iMac12,1 */
538 .matches = {
539 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
540 DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,1"),
541 },
542 },
543 {
544 /* https://gitlab.freedesktop.org/drm/amd/-/issues/2753 */
545 .callback = video_detect_force_native,
546 /* Apple iMac12,2 */
547 .matches = {
548 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
549 DMI_MATCH(DMI_PRODUCT_NAME, "iMac12,2"),
550 },
551 },
552 {
553 .callback = video_detect_force_native,
554 /* Apple MacBook Air 7,2 */
555 .matches = {
556 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
557 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir7,2"),
558 },
559 },
560 {
561 .callback = video_detect_force_native,
562 /* Apple MacBook Air 9,1 */
563 .matches = {
564 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
565 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookAir9,1"),
566 },
567 },
568 {
569 .callback = video_detect_force_native,
570 /* Apple MacBook Pro 9,2 */
571 .matches = {
572 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
573 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro9,2"),
574 },
575 },
576 {
577 .callback = video_detect_force_native,
578 /* Apple MacBook Pro 11,2 */
579 .matches = {
580 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
581 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro11,2"),
582 },
583 },
584 {
585 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
586 .callback = video_detect_force_native,
587 /* Apple MacBook Pro 12,1 */
588 .matches = {
589 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
590 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
591 },
592 },
593 {
594 .callback = video_detect_force_native,
595 /* Apple MacBook Pro 16,2 */
596 .matches = {
597 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
598 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro16,2"),
599 },
600 },
601 {
602 .callback = video_detect_force_native,
603 /* Dell Inspiron N4010 */
604 .matches = {
605 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
606 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron N4010"),
607 },
608 },
609 {
610 .callback = video_detect_force_native,
611 /* Dell Vostro V131 */
612 .matches = {
613 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
614 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
615 },
616 },
617 {
618 /* https://bugzilla.redhat.com/show_bug.cgi?id=1123661 */
619 .callback = video_detect_force_native,
620 /* Dell XPS 17 L702X */
621 .matches = {
622 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
623 DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
624 },
625 },
626 {
627 .callback = video_detect_force_native,
628 /* Dell Precision 7510 */
629 .matches = {
630 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
631 DMI_MATCH(DMI_PRODUCT_NAME, "Precision 7510"),
632 },
633 },
634 {
635 .callback = video_detect_force_native,
636 /* Dell Studio 1569 */
637 .matches = {
638 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
639 DMI_MATCH(DMI_PRODUCT_NAME, "Studio 1569"),
640 },
641 },
642 {
643 .callback = video_detect_force_native,
644 /* Acer Aspire 3830TG */
645 .matches = {
646 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
647 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 3830TG"),
648 },
649 },
650 {
651 .callback = video_detect_force_native,
652 /* Acer Aspire 4810T */
653 .matches = {
654 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
655 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 4810T"),
656 },
657 },
658 {
659 .callback = video_detect_force_native,
660 /* Acer Aspire 5738z */
661 .matches = {
662 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
663 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5738"),
664 DMI_MATCH(DMI_BOARD_NAME, "JV50"),
665 },
666 },
667 {
668 /* https://bugzilla.redhat.com/show_bug.cgi?id=1012674 */
669 .callback = video_detect_force_native,
670 /* Acer Aspire 5741 */
671 .matches = {
672 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
673 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5741"),
674 },
675 },
676 {
677 /* https://bugzilla.kernel.org/show_bug.cgi?id=42993 */
678 .callback = video_detect_force_native,
679 /* Acer Aspire 5750 */
680 .matches = {
681 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
682 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5750"),
683 },
684 },
685 {
686 /* https://bugzilla.kernel.org/show_bug.cgi?id=42833 */
687 .callback = video_detect_force_native,
688 /* Acer Extensa 5235 */
689 .matches = {
690 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
691 DMI_MATCH(DMI_PRODUCT_NAME, "Extensa 5235"),
692 },
693 },
694 {
695 .callback = video_detect_force_native,
696 /* Acer TravelMate 4750 */
697 .matches = {
698 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
699 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4750"),
700 },
701 },
702 {
703 /* https://bugzilla.kernel.org/show_bug.cgi?id=207835 */
704 .callback = video_detect_force_native,
705 /* Acer TravelMate 5735Z */
706 .matches = {
707 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
708 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5735Z"),
709 DMI_MATCH(DMI_BOARD_NAME, "BA51_MV"),
710 },
711 },
712 {
713 /* https://bugzilla.kernel.org/show_bug.cgi?id=36322 */
714 .callback = video_detect_force_native,
715 /* Acer TravelMate 5760 */
716 .matches = {
717 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
718 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 5760"),
719 },
720 },
721 {
722 .callback = video_detect_force_native,
723 /* ASUSTeK COMPUTER INC. GA401 */
724 .matches = {
725 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
726 DMI_MATCH(DMI_PRODUCT_NAME, "GA401"),
727 },
728 },
729 {
730 .callback = video_detect_force_native,
731 /* ASUSTeK COMPUTER INC. GA502 */
732 .matches = {
733 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
734 DMI_MATCH(DMI_PRODUCT_NAME, "GA502"),
735 },
736 },
737 {
738 .callback = video_detect_force_native,
739 /* ASUSTeK COMPUTER INC. GA503 */
740 .matches = {
741 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
742 DMI_MATCH(DMI_PRODUCT_NAME, "GA503"),
743 },
744 },
745 {
746 .callback = video_detect_force_native,
747 /* Asus U46E */
748 .matches = {
749 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
750 DMI_MATCH(DMI_PRODUCT_NAME, "U46E"),
751 },
752 },
753 {
754 .callback = video_detect_force_native,
755 /* Asus UX303UB */
756 .matches = {
757 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
758 DMI_MATCH(DMI_PRODUCT_NAME, "UX303UB"),
759 },
760 },
761 {
762 .callback = video_detect_force_native,
763 /* HP EliteBook 8460p */
764 .matches = {
765 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
766 DMI_MATCH(DMI_PRODUCT_NAME, "HP EliteBook 8460p"),
767 },
768 },
769 {
770 .callback = video_detect_force_native,
771 /* HP Pavilion g6-1d80nr / B4U19UA */
772 .matches = {
773 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
774 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion g6 Notebook PC"),
775 DMI_MATCH(DMI_PRODUCT_SKU, "B4U19UA"),
776 },
777 },
778 {
779 .callback = video_detect_force_native,
780 /* Samsung N150P */
781 .matches = {
782 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
783 DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
784 DMI_MATCH(DMI_BOARD_NAME, "N150P"),
785 },
786 },
787 {
788 .callback = video_detect_force_native,
789 /* Samsung N145P/N250P/N260P */
790 .matches = {
791 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
792 DMI_MATCH(DMI_PRODUCT_NAME, "N145P/N250P/N260P"),
793 DMI_MATCH(DMI_BOARD_NAME, "N145P/N250P/N260P"),
794 },
795 },
796 {
797 .callback = video_detect_force_native,
798 /* Samsung N250P */
799 .matches = {
800 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
801 DMI_MATCH(DMI_PRODUCT_NAME, "N250P"),
802 DMI_MATCH(DMI_BOARD_NAME, "N250P"),
803 },
804 },
805 {
806 /* https://bugzilla.kernel.org/show_bug.cgi?id=202401 */
807 .callback = video_detect_force_native,
808 /* Sony Vaio VPCEH3U1E */
809 .matches = {
810 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
811 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEH3U1E"),
812 },
813 },
814 {
815 .callback = video_detect_force_native,
816 /* Sony Vaio VPCY11S1E */
817 .matches = {
818 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
819 DMI_MATCH(DMI_PRODUCT_NAME, "VPCY11S1E"),
820 },
821 },
822
823 /*
824 * These Toshibas have a broken acpi-video interface for brightness
825 * control. They also have an issue where the panel is off after
826 * suspend until a special firmware call is made to turn it back
827 * on. This is handled by the toshiba_acpi kernel module, so that
828 * module must be enabled for these models to work correctly.
829 */
830 {
831 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
832 .callback = video_detect_force_native,
833 /* Toshiba Portégé R700 */
834 .matches = {
835 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
836 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
837 },
838 },
839 {
840 /* Portégé: https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
841 /* Satellite: https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
842 .callback = video_detect_force_native,
843 /* Toshiba Satellite/Portégé R830 */
844 .matches = {
845 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
846 DMI_MATCH(DMI_PRODUCT_NAME, "R830"),
847 },
848 },
849 {
850 .callback = video_detect_force_native,
851 /* Toshiba Satellite/Portégé Z830 */
852 .matches = {
853 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
854 DMI_MATCH(DMI_PRODUCT_NAME, "Z830"),
855 },
856 },
857
858 /*
859 * Dell AIO (All in Ones) which advertise an UART attached backlight
860 * controller board in their ACPI tables (and may even have one), but
861 * which need native backlight control nevertheless.
862 */
863 {
864 /* https://github.com/zabbly/linux/issues/26 */
865 .callback = video_detect_force_native,
866 /* Dell OptiPlex 5480 AIO */
867 .matches = {
868 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
869 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 5480 AIO"),
870 },
871 },
872 {
873 /* https://bugzilla.redhat.com/show_bug.cgi?id=2303936 */
874 .callback = video_detect_force_native,
875 /* Dell OptiPlex 7760 AIO */
876 .matches = {
877 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
878 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7760 AIO"),
879 },
880 },
881
882 /*
883 * Models which have nvidia-ec-wmi support, but should not use it.
884 * Note this indicates a likely firmware bug on these models and should
885 * be revisited if/when Linux gets support for dynamic mux mode.
886 */
887 {
888 .callback = video_detect_force_native,
889 /* Dell G15 5515 */
890 .matches = {
891 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
892 DMI_MATCH(DMI_PRODUCT_NAME, "Dell G15 5515"),
893 },
894 },
895 {
896 .callback = video_detect_force_native,
897 .matches = {
898 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
899 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 15 3535"),
900 },
901 },
902
903 /*
904 * x86 android tablets which directly control the backlight through
905 * an external backlight controller, typically TI's LP8557.
906 * The backlight is directly controlled by the lp855x driver on these.
907 * This setup means that neither i915's native nor acpi_video backlight
908 * control works. Add a "vendor" quirk to disable both. Note these
909 * devices do not use vendor control in the typical meaning of
910 * vendor specific SMBIOS or ACPI calls being used.
911 */
912 {
913 .callback = video_detect_force_vendor,
914 /* Lenovo Yoga Book X90F / X90L */
915 .matches = {
916 DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
917 DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "CHERRYVIEW D1 PLATFORM"),
918 DMI_EXACT_MATCH(DMI_PRODUCT_VERSION, "YETI-11"),
919 },
920 },
921 {
922 .callback = video_detect_force_vendor,
923 /*
924 * Lenovo Yoga Tablet 2 830F/L or 1050F/L (The 8" and 10"
925 * Lenovo Yoga Tablet 2 use the same mainboard)
926 */
927 .matches = {
928 DMI_MATCH(DMI_SYS_VENDOR, "Intel Corp."),
929 DMI_MATCH(DMI_PRODUCT_NAME, "VALLEYVIEW C0 PLATFORM"),
930 DMI_MATCH(DMI_BOARD_NAME, "BYT-T FFD8"),
931 /* Partial match on beginning of BIOS version */
932 DMI_MATCH(DMI_BIOS_VERSION, "BLADE_21"),
933 },
934 },
935 {
936 .callback = video_detect_force_vendor,
937 /* Lenovo Yoga Tab 3 Pro YT3-X90F */
938 .matches = {
939 DMI_MATCH(DMI_SYS_VENDOR, "Intel Corporation"),
940 DMI_MATCH(DMI_PRODUCT_VERSION, "Blade3-10A-001"),
941 },
942 },
943 {
944 .callback = video_detect_force_vendor,
945 /* Xiaomi Mi Pad 2 */
946 .matches = {
947 DMI_MATCH(DMI_SYS_VENDOR, "Xiaomi Inc"),
948 DMI_MATCH(DMI_PRODUCT_NAME, "Mipad2"),
949 },
950 },
951 { },
952};
953
954static bool google_cros_ec_present(void)
955{
956 return acpi_dev_found("GOOG0004") || acpi_dev_found("GOOG000C");
957}
958
959/*
960 * Windows 8 and newer no longer use the ACPI video interface, so it often
961 * does not work. So on win8+ systems prefer native brightness control.
962 * Chromebooks should always prefer native backlight control.
963 */
964static bool prefer_native_over_acpi_video(void)
965{
966 return acpi_osi_is_win8() || google_cros_ec_present();
967}
968
969/*
970 * Determine which type of backlight interface to use on this system,
971 * First check cmdline, then dmi quirks, then do autodetect.
972 */
973enum acpi_backlight_type __acpi_video_get_backlight_type(bool native, bool *auto_detect)
974{
975 static DEFINE_MUTEX(init_mutex);
976 static bool nvidia_wmi_ec_present;
977 static bool apple_gmux_present;
978 static bool dell_uart_present;
979 static bool native_available;
980 static bool init_done;
981 static long video_caps;
982
983 /* Parse cmdline, dmi and acpi only once */
984 mutex_lock(&init_mutex);
985 if (!init_done) {
986 acpi_video_parse_cmdline();
987 dmi_check_system(video_detect_dmi_table);
988 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
989 ACPI_UINT32_MAX, find_video, NULL,
990 &video_caps, NULL);
991 nvidia_wmi_ec_present = nvidia_wmi_ec_supported();
992 apple_gmux_present = apple_gmux_detect(NULL, NULL);
993 dell_uart_present = acpi_dev_present("DELL0501", NULL, -1);
994 init_done = true;
995 }
996 if (native)
997 native_available = true;
998 mutex_unlock(&init_mutex);
999
1000 if (auto_detect)
1001 *auto_detect = false;
1002
1003 /*
1004 * The below heuristics / detection steps are in order of descending
1005 * presedence. The commandline takes presedence over anything else.
1006 */
1007 if (acpi_backlight_cmdline != acpi_backlight_undef)
1008 return acpi_backlight_cmdline;
1009
1010 /* DMI quirks override any autodetection. */
1011 if (acpi_backlight_dmi != acpi_backlight_undef)
1012 return acpi_backlight_dmi;
1013
1014 if (auto_detect)
1015 *auto_detect = true;
1016
1017 /* Special cases such as nvidia_wmi_ec and apple gmux. */
1018 if (nvidia_wmi_ec_present)
1019 return acpi_backlight_nvidia_wmi_ec;
1020
1021 if (apple_gmux_present)
1022 return acpi_backlight_apple_gmux;
1023
1024 if (dell_uart_present)
1025 return acpi_backlight_dell_uart;
1026
1027 /* Use ACPI video if available, except when native should be preferred. */
1028 if ((video_caps & ACPI_VIDEO_BACKLIGHT) &&
1029 !(native_available && prefer_native_over_acpi_video()))
1030 return acpi_backlight_video;
1031
1032 /* Use native if available */
1033 if (native_available)
1034 return acpi_backlight_native;
1035
1036 /*
1037 * The vendor specific BIOS interfaces are only necessary for
1038 * laptops from before ~2008.
1039 *
1040 * For laptops from ~2008 till ~2023 this point is never reached
1041 * because on those (video_caps & ACPI_VIDEO_BACKLIGHT) above is true.
1042 *
1043 * Laptops from after ~2023 no longer support ACPI_VIDEO_BACKLIGHT,
1044 * if this point is reached on those, this likely means that
1045 * the GPU kms driver which sets native_available has not loaded yet.
1046 *
1047 * Returning acpi_backlight_vendor in this case is known to sometimes
1048 * cause a non working vendor specific /sys/class/backlight device to
1049 * get registered.
1050 *
1051 * Return acpi_backlight_none on laptops with ACPI tables written
1052 * for Windows 8 (laptops from after ~2012) to avoid this problem.
1053 */
1054 if (acpi_osi_is_win8())
1055 return acpi_backlight_none;
1056
1057 /* No ACPI video/native (old hw), use vendor specific fw methods. */
1058 return acpi_backlight_vendor;
1059}
1060EXPORT_SYMBOL(__acpi_video_get_backlight_type);