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 #include "internal.h" 42 43 ACPI_MODULE_NAME("video"); 44 #define _COMPONENT ACPI_VIDEO_COMPONENT 45 46 static long acpi_video_support; 47 static bool acpi_video_caps_checked; 48 49 static acpi_status 50 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context, 51 void **return_value) 52 { 53 long *cap = context; 54 55 if (acpi_has_method(handle, "_BCM") && 56 acpi_has_method(handle, "_BCL")) { 57 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight " 58 "support\n")); 59 *cap |= ACPI_VIDEO_BACKLIGHT; 60 if (!acpi_has_method(handle, "_BQC")) 61 printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, " 62 "cannot determine initial brightness\n"); 63 /* We have backlight support, no need to scan further */ 64 return AE_CTRL_TERMINATE; 65 } 66 return 0; 67 } 68 69 /* Returns true if the ACPI object is a video device which can be 70 * handled by video.ko. 71 * The device will get a Linux specific CID added in scan.c to 72 * identify the device as an ACPI graphics device 73 * Be aware that the graphics device may not be physically present 74 * Use acpi_video_get_capabilities() to detect general ACPI video 75 * capabilities of present cards 76 */ 77 long acpi_is_video_device(acpi_handle handle) 78 { 79 long video_caps = 0; 80 81 /* Is this device able to support video switching ? */ 82 if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS")) 83 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING; 84 85 /* Is this device able to retrieve a video ROM ? */ 86 if (acpi_has_method(handle, "_ROM")) 87 video_caps |= ACPI_VIDEO_ROM_AVAILABLE; 88 89 /* Is this device able to configure which video head to be POSTed ? */ 90 if (acpi_has_method(handle, "_VPO") && 91 acpi_has_method(handle, "_GPD") && 92 acpi_has_method(handle, "_SPD")) 93 video_caps |= ACPI_VIDEO_DEVICE_POSTING; 94 95 /* Only check for backlight functionality if one of the above hit. */ 96 if (video_caps) 97 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 98 ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL, 99 &video_caps, NULL); 100 101 return video_caps; 102 } 103 EXPORT_SYMBOL(acpi_is_video_device); 104 105 static acpi_status 106 find_video(acpi_handle handle, u32 lvl, void *context, void **rv) 107 { 108 long *cap = context; 109 struct pci_dev *dev; 110 struct acpi_device *acpi_dev; 111 112 const struct acpi_device_id video_ids[] = { 113 {ACPI_VIDEO_HID, 0}, 114 {"", 0}, 115 }; 116 if (acpi_bus_get_device(handle, &acpi_dev)) 117 return AE_OK; 118 119 if (!acpi_match_device_ids(acpi_dev, video_ids)) { 120 dev = acpi_get_pci_dev(handle); 121 if (!dev) 122 return AE_OK; 123 pci_dev_put(dev); 124 *cap |= acpi_is_video_device(handle); 125 } 126 return AE_OK; 127 } 128 129 /* Force to use vendor driver when the ACPI device is known to be 130 * buggy */ 131 static int video_detect_force_vendor(const struct dmi_system_id *d) 132 { 133 acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; 134 return 0; 135 } 136 137 static struct dmi_system_id video_detect_dmi_table[] = { 138 /* On Samsung X360, the BIOS will set a flag (VDRV) if generic 139 * ACPI backlight device is used. This flag will definitively break 140 * the backlight interface (even the vendor interface) untill next 141 * reboot. It's why we should prevent video.ko from being used here 142 * and we can't rely on a later call to acpi_video_unregister(). 143 */ 144 { 145 .callback = video_detect_force_vendor, 146 .ident = "X360", 147 .matches = { 148 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."), 149 DMI_MATCH(DMI_PRODUCT_NAME, "X360"), 150 DMI_MATCH(DMI_BOARD_NAME, "X360"), 151 }, 152 }, 153 { 154 .callback = video_detect_force_vendor, 155 .ident = "Asus UL30VT", 156 .matches = { 157 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 158 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"), 159 }, 160 }, 161 { 162 .callback = video_detect_force_vendor, 163 .ident = "Asus UL30A", 164 .matches = { 165 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."), 166 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"), 167 }, 168 }, 169 { 170 .callback = video_detect_force_vendor, 171 .ident = "Dell Inspiron 5737", 172 .matches = { 173 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 174 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"), 175 }, 176 }, 177 { 178 .callback = video_detect_force_vendor, 179 .ident = "Lenovo IdeaPad Z570", 180 .matches = { 181 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), 182 DMI_MATCH(DMI_PRODUCT_VERSION, "Ideapad Z570"), 183 }, 184 }, 185 { }, 186 }; 187 188 /* 189 * Returns the video capabilities of a specific ACPI graphics device 190 * 191 * if NULL is passed as argument all ACPI devices are enumerated and 192 * all graphics capabilities of physically present devices are 193 * summarized and returned. This is cached and done only once. 194 */ 195 long acpi_video_get_capabilities(acpi_handle graphics_handle) 196 { 197 long caps = 0; 198 struct acpi_device *tmp_dev; 199 acpi_status status; 200 201 if (acpi_video_caps_checked && graphics_handle == NULL) 202 return acpi_video_support; 203 204 if (!graphics_handle) { 205 /* Only do the global walk through all graphics devices once */ 206 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 207 ACPI_UINT32_MAX, find_video, NULL, 208 &caps, NULL); 209 /* There might be boot param flags set already... */ 210 acpi_video_support |= caps; 211 acpi_video_caps_checked = 1; 212 /* Add blacklists here. Be careful to use the right *DMI* bits 213 * to still be able to override logic via boot params, e.g.: 214 * 215 * if (dmi_name_in_vendors("XY")) { 216 * acpi_video_support |= 217 * ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; 218 *} 219 */ 220 221 dmi_check_system(video_detect_dmi_table); 222 } else { 223 status = acpi_bus_get_device(graphics_handle, &tmp_dev); 224 if (ACPI_FAILURE(status)) { 225 ACPI_EXCEPTION((AE_INFO, status, "Invalid device")); 226 return 0; 227 } 228 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle, 229 ACPI_UINT32_MAX, find_video, NULL, 230 &caps, NULL); 231 } 232 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n", 233 graphics_handle ? caps : acpi_video_support, 234 graphics_handle ? "on device " : "in general", 235 graphics_handle ? acpi_device_bid(tmp_dev) : "")); 236 return caps; 237 } 238 EXPORT_SYMBOL(acpi_video_get_capabilities); 239 240 static void acpi_video_caps_check(void) 241 { 242 /* 243 * We must check whether the ACPI graphics device is physically plugged 244 * in. Therefore this must be called after binding PCI and ACPI devices 245 */ 246 if (!acpi_video_caps_checked) 247 acpi_video_get_capabilities(NULL); 248 } 249 250 bool acpi_osi_is_win8(void) 251 { 252 return acpi_gbl_osi_data >= ACPI_OSI_WIN_8; 253 } 254 EXPORT_SYMBOL(acpi_osi_is_win8); 255 256 /* Promote the vendor interface instead of the generic video module. 257 * This function allow DMI blacklists to be implemented by externals 258 * platform drivers instead of putting a big blacklist in video_detect.c 259 * After calling this function you will probably want to call 260 * acpi_video_unregister() to make sure the video module is not loaded 261 */ 262 void acpi_video_dmi_promote_vendor(void) 263 { 264 acpi_video_caps_check(); 265 acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; 266 } 267 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor); 268 269 /* To be called when a driver who previously promoted the vendor 270 * interface */ 271 void acpi_video_dmi_demote_vendor(void) 272 { 273 acpi_video_caps_check(); 274 acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR; 275 } 276 EXPORT_SYMBOL(acpi_video_dmi_demote_vendor); 277 278 /* Returns true if video.ko can do backlight switching */ 279 int acpi_video_backlight_support(void) 280 { 281 acpi_video_caps_check(); 282 283 /* First check for boot param -> highest prio */ 284 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR) 285 return 0; 286 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO) 287 return 1; 288 289 /* Then check for DMI blacklist -> second highest prio */ 290 if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR) 291 return 0; 292 else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO) 293 return 1; 294 295 /* Then go the default way */ 296 return acpi_video_support & ACPI_VIDEO_BACKLIGHT; 297 } 298 EXPORT_SYMBOL(acpi_video_backlight_support); 299 300 /* 301 * Use acpi_backlight=vendor/video to force that backlight switching 302 * is processed by vendor specific acpi drivers or video.ko driver. 303 */ 304 static int __init acpi_backlight(char *str) 305 { 306 if (str == NULL || *str == '\0') 307 return 1; 308 else { 309 if (!strcmp("vendor", str)) 310 acpi_video_support |= 311 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR; 312 if (!strcmp("video", str)) 313 acpi_video_support |= 314 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO; 315 } 316 return 1; 317 } 318 __setup("acpi_backlight=", acpi_backlight); 319