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 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 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 */ 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 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 } 99 100 static int video_detect_force_native(const struct dmi_system_id *d) 101 { 102 acpi_backlight_dmi = acpi_backlight_native; 103 return 0; 104 } 105 106 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(). 112 */ 113 { 114 .callback = video_detect_force_vendor, 115 .ident = "X360", 116 .matches = { 117 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 118 DMI_MATCH(DMI_PRODUCT_NAME, "X360"), 119 DMI_MATCH(DMI_BOARD_NAME, "X360"), 120 }, 121 }, 122 { 123 .callback = video_detect_force_vendor, 124 .ident = "Asus UL30VT", 125 .matches = { 126 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 127 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"), 128 }, 129 }, 130 { 131 .callback = video_detect_force_vendor, 132 .ident = "Asus UL30A", 133 .matches = { 134 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 135 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"), 136 }, 137 }, 138 { 139 .callback = video_detect_force_vendor, 140 .ident = "Dell Inspiron 5737", 141 .matches = { 142 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 143 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"), 144 }, 145 }, 146 147 /* 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 153 */ 154 { 155 .callback = video_detect_force_video, 156 .ident = "ThinkPad T420", 157 .matches = { 158 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 159 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"), 160 }, 161 }, 162 { 163 .callback = video_detect_force_video, 164 .ident = "ThinkPad T520", 165 .matches = { 166 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 167 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"), 168 }, 169 }, 170 { 171 .callback = video_detect_force_video, 172 .ident = "ThinkPad X201s", 173 .matches = { 174 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 175 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"), 176 }, 177 }, 178 179 /* The native backlight controls do not work on some older machines */ 180 { 181 /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */ 182 .callback = video_detect_force_video, 183 .ident = "HP ENVY 15 Notebook", 184 .matches = { 185 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 186 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"), 187 }, 188 }, 189 { 190 .callback = video_detect_force_video, 191 .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E", 192 .matches = { 193 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 194 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"), 195 }, 196 }, 197 { 198 .callback = video_detect_force_video, 199 .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V", 200 .matches = { 201 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 202 DMI_MATCH(DMI_PRODUCT_NAME, 203 "370R4E/370R4V/370R5E/3570RE/370R5V"), 204 }, 205 }, 206 { 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", 210 .matches = { 211 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 212 DMI_MATCH(DMI_PRODUCT_NAME, 213 "3570R/370R/470R/450R/510R/4450RV"), 214 }, 215 }, 216 { 217 /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */ 218 .callback = video_detect_force_video, 219 .ident = "SAMSUNG 730U3E/740U3E", 220 .matches = { 221 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 222 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"), 223 }, 224 }, 225 { 226 /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */ 227 .callback = video_detect_force_video, 228 .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D", 229 .matches = { 230 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 231 DMI_MATCH(DMI_PRODUCT_NAME, 232 "900X3C/900X3D/900X3E/900X4C/900X4D"), 233 }, 234 }, 235 { 236 /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */ 237 .callback = video_detect_force_video, 238 .ident = "Dell XPS15 L521X", 239 .matches = { 240 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 241 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"), 242 }, 243 }, 244 245 /* Non win8 machines which need native backlight nevertheless */ 246 { 247 /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */ 248 .callback = video_detect_force_native, 249 .ident = "Lenovo Ideapad Z570", 250 .matches = { 251 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 252 DMI_MATCH(DMI_PRODUCT_NAME, "102434U"), 253 }, 254 }, 255 { 256 /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */ 257 .callback = video_detect_force_native, 258 .ident = "Apple MacBook Pro 12,1", 259 .matches = { 260 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 261 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"), 262 }, 263 }, 264 { }, 265 }; 266 267 /* This uses a workqueue to avoid various locking ordering issues */ 268 static void acpi_video_backlight_notify_work(struct work_struct *work) 269 { 270 if (acpi_video_get_backlight_type() != acpi_backlight_video) 271 acpi_video_unregister_backlight(); 272 } 273 274 static int acpi_video_backlight_notify(struct notifier_block *nb, 275 unsigned long val, void *bd) 276 { 277 struct backlight_device *backlight = bd; 278 279 /* A raw bl registering may change video -> native */ 280 if (backlight->props.type == BACKLIGHT_RAW && 281 val == BACKLIGHT_REGISTERED) 282 schedule_work(&backlight_notify_work); 283 284 return NOTIFY_OK; 285 } 286 287 /* 288 * Determine which type of backlight interface to use on this system, 289 * First check cmdline, then dmi quirks, then do autodetect. 290 * 291 * The autodetect order is: 292 * 1) Is the acpi-video backlight interface supported -> 293 * no, use a vendor interface 294 * 2) Is this a win8 "ready" BIOS and do we have a native interface -> 295 * yes, use a native interface 296 * 3) Else use the acpi-video interface 297 * 298 * Arguably the native on win8 check should be done first, but that would 299 * be a behavior change, which may causes issues. 300 */ 301 enum acpi_backlight_type acpi_video_get_backlight_type(void) 302 { 303 static DEFINE_MUTEX(init_mutex); 304 static bool init_done; 305 static long video_caps; 306 307 /* Parse cmdline, dmi and acpi only once */ 308 mutex_lock(&init_mutex); 309 if (!init_done) { 310 acpi_video_parse_cmdline(); 311 dmi_check_system(video_detect_dmi_table); 312 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 313 ACPI_UINT32_MAX, find_video, NULL, 314 &video_caps, NULL); 315 INIT_WORK(&backlight_notify_work, 316 acpi_video_backlight_notify_work); 317 backlight_nb.notifier_call = acpi_video_backlight_notify; 318 backlight_nb.priority = 0; 319 if (backlight_register_notifier(&backlight_nb) == 0) 320 backlight_notifier_registered = true; 321 init_done = true; 322 } 323 mutex_unlock(&init_mutex); 324 325 if (acpi_backlight_cmdline != acpi_backlight_undef) 326 return acpi_backlight_cmdline; 327 328 if (acpi_backlight_dmi != acpi_backlight_undef) 329 return acpi_backlight_dmi; 330 331 if (!(video_caps & ACPI_VIDEO_BACKLIGHT)) 332 return acpi_backlight_vendor; 333 334 if (acpi_osi_is_win8() && backlight_device_registered(BACKLIGHT_RAW)) 335 return acpi_backlight_native; 336 337 return acpi_backlight_video; 338 } 339 EXPORT_SYMBOL(acpi_video_get_backlight_type); 340 341 /* 342 * Set the preferred backlight interface type based on DMI info. 343 * This function allows DMI blacklists to be implemented by external 344 * platform drivers instead of putting a big blacklist in video_detect.c 345 */ 346 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type) 347 { 348 acpi_backlight_dmi = type; 349 /* Remove acpi-video backlight interface if it is no longer desired */ 350 if (acpi_video_get_backlight_type() != acpi_backlight_video) 351 acpi_video_unregister_backlight(); 352 } 353 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type); 354 355 void __exit acpi_video_detect_exit(void) 356 { 357 if (backlight_notifier_registered) 358 backlight_unregister_notifier(&backlight_nb); 359 } 360