1 /* 2 * Copyright © 2015 Intel Corporation 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 */ 24 25 /* 26 * Laptops with Intel GPUs which have panels that support controlling the 27 * backlight through DP AUX can actually use two different interfaces: Intel's 28 * proprietary DP AUX backlight interface, and the standard VESA backlight 29 * interface. Unfortunately, at the time of writing this a lot of laptops will 30 * advertise support for the standard VESA backlight interface when they 31 * don't properly support it. However, on these systems the Intel backlight 32 * interface generally does work properly. Additionally, these systems will 33 * usually just indicate that they use PWM backlight controls in their VBIOS 34 * for some reason. 35 */ 36 37 #include "i915_drv.h" 38 #include "intel_backlight.h" 39 #include "intel_display_types.h" 40 #include "intel_dp.h" 41 #include "intel_dp_aux_backlight.h" 42 43 /* TODO: 44 * Implement HDR, right now we just implement the bare minimum to bring us back into SDR mode so we 45 * can make people's backlights work in the mean time 46 */ 47 48 /* 49 * DP AUX registers for Intel's proprietary HDR backlight interface. We define 50 * them here since we'll likely be the only driver to ever use these. 51 */ 52 #define INTEL_EDP_HDR_TCON_CAP0 0x340 53 54 #define INTEL_EDP_HDR_TCON_CAP1 0x341 55 # define INTEL_EDP_HDR_TCON_2084_DECODE_CAP BIT(0) 56 # define INTEL_EDP_HDR_TCON_2020_GAMUT_CAP BIT(1) 57 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_CAP BIT(2) 58 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_CAP BIT(3) 59 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP BIT(4) 60 # define INTEL_EDP_HDR_TCON_OPTIMIZATION_CAP BIT(5) 61 # define INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_CAP BIT(6) 62 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_CONVERSION_CAP BIT(7) 63 64 #define INTEL_EDP_HDR_TCON_CAP2 0x342 65 # define INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP BIT(0) 66 67 #define INTEL_EDP_HDR_TCON_CAP3 0x343 68 69 #define INTEL_EDP_HDR_GETSET_CTRL_PARAMS 0x344 70 # define INTEL_EDP_HDR_TCON_2084_DECODE_ENABLE BIT(0) 71 # define INTEL_EDP_HDR_TCON_2020_GAMUT_ENABLE BIT(1) 72 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_ENABLE BIT(2) /* Pre-TGL+ */ 73 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_ENABLE BIT(3) 74 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE BIT(4) 75 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_ENABLE BIT(5) 76 /* Bit 6 is reserved */ 77 # define INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_ENABLE BIT(7) 78 79 #define INTEL_EDP_HDR_CONTENT_LUMINANCE 0x346 /* Pre-TGL+ */ 80 #define INTEL_EDP_HDR_PANEL_LUMINANCE_OVERRIDE 0x34A 81 #define INTEL_EDP_SDR_LUMINANCE_LEVEL 0x352 82 #define INTEL_EDP_BRIGHTNESS_NITS_LSB 0x354 83 #define INTEL_EDP_BRIGHTNESS_NITS_MSB 0x355 84 #define INTEL_EDP_BRIGHTNESS_DELAY_FRAMES 0x356 85 #define INTEL_EDP_BRIGHTNESS_PER_FRAME_STEPS 0x357 86 87 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_0 0x358 88 # define INTEL_EDP_TCON_USAGE_MASK GENMASK(0, 3) 89 # define INTEL_EDP_TCON_USAGE_UNKNOWN 0x0 90 # define INTEL_EDP_TCON_USAGE_DESKTOP 0x1 91 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_MEDIA 0x2 92 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_GAMING 0x3 93 # define INTEL_EDP_TCON_POWER_MASK BIT(4) 94 # define INTEL_EDP_TCON_POWER_DC (0 << 4) 95 # define INTEL_EDP_TCON_POWER_AC (1 << 4) 96 # define INTEL_EDP_TCON_OPTIMIZATION_STRENGTH_MASK GENMASK(5, 7) 97 98 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_1 0x359 99 100 enum intel_dp_aux_backlight_modparam { 101 INTEL_DP_AUX_BACKLIGHT_AUTO = -1, 102 INTEL_DP_AUX_BACKLIGHT_OFF = 0, 103 INTEL_DP_AUX_BACKLIGHT_ON = 1, 104 INTEL_DP_AUX_BACKLIGHT_FORCE_VESA = 2, 105 INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL = 3, 106 }; 107 108 /* Intel EDP backlight callbacks */ 109 static bool 110 intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector) 111 { 112 struct drm_i915_private *i915 = to_i915(connector->base.dev); 113 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 114 struct drm_dp_aux *aux = &intel_dp->aux; 115 struct intel_panel *panel = &connector->panel; 116 int ret; 117 u8 tcon_cap[4]; 118 119 intel_dp_wait_source_oui(intel_dp); 120 121 ret = drm_dp_dpcd_read(aux, INTEL_EDP_HDR_TCON_CAP0, tcon_cap, sizeof(tcon_cap)); 122 if (ret != sizeof(tcon_cap)) 123 return false; 124 125 if (!(tcon_cap[1] & INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP)) 126 return false; 127 128 if (tcon_cap[0] >= 1) { 129 drm_dbg_kms(&i915->drm, "Detected Intel HDR backlight interface version %d\n", 130 tcon_cap[0]); 131 } else { 132 drm_dbg_kms(&i915->drm, "Detected unsupported HDR backlight interface version %d\n", 133 tcon_cap[0]); 134 return false; 135 } 136 137 /* 138 * If we don't have HDR static metadata there is no way to 139 * runtime detect used range for nits based control. For now 140 * do not use Intel proprietary eDP backlight control if we 141 * don't have this data in panel EDID. In case we find panel 142 * which supports only nits based control, but doesn't provide 143 * HDR static metadata we need to start maintaining table of 144 * ranges for such panels. 145 */ 146 if (i915->params.enable_dpcd_backlight != INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL && 147 !(connector->base.hdr_sink_metadata.hdmi_type1.metadata_type & 148 BIT(HDMI_STATIC_METADATA_TYPE1))) { 149 drm_info(&i915->drm, 150 "Panel is missing HDR static metadata. Possible support for Intel HDR backlight interface is not used. If your backlight controls don't work try booting with i915.enable_dpcd_backlight=%d. needs this, please file a _new_ bug report on drm/i915, see " FDO_BUG_URL " for details.\n", 151 INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL); 152 return false; 153 } 154 155 panel->backlight.edp.intel.sdr_uses_aux = 156 tcon_cap[2] & INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP; 157 158 return true; 159 } 160 161 static u32 162 intel_dp_aux_hdr_get_backlight(struct intel_connector *connector, enum pipe pipe) 163 { 164 struct drm_i915_private *i915 = to_i915(connector->base.dev); 165 struct intel_panel *panel = &connector->panel; 166 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 167 u8 tmp; 168 u8 buf[2] = { 0 }; 169 170 if (drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &tmp) != 1) { 171 drm_err(&i915->drm, "Failed to read current backlight mode from DPCD\n"); 172 return 0; 173 } 174 175 if (!(tmp & INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE)) { 176 if (!panel->backlight.edp.intel.sdr_uses_aux) { 177 u32 pwm_level = panel->backlight.pwm_funcs->get(connector, pipe); 178 179 return intel_backlight_level_from_pwm(connector, pwm_level); 180 } 181 182 /* Assume 100% brightness if backlight controls aren't enabled yet */ 183 return panel->backlight.max; 184 } 185 186 if (drm_dp_dpcd_read(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, 187 sizeof(buf)) != sizeof(buf)) { 188 drm_err(&i915->drm, "Failed to read brightness from DPCD\n"); 189 return 0; 190 } 191 192 return (buf[1] << 8 | buf[0]); 193 } 194 195 static void 196 intel_dp_aux_hdr_set_aux_backlight(const struct drm_connector_state *conn_state, u32 level) 197 { 198 struct intel_connector *connector = to_intel_connector(conn_state->connector); 199 struct drm_device *dev = connector->base.dev; 200 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 201 u8 buf[4] = { 0 }; 202 203 buf[0] = level & 0xFF; 204 buf[1] = (level & 0xFF00) >> 8; 205 206 if (drm_dp_dpcd_write(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf, 207 sizeof(buf)) != sizeof(buf)) 208 drm_err(dev, "Failed to write brightness level to DPCD\n"); 209 } 210 211 static void 212 intel_dp_aux_hdr_set_backlight(const struct drm_connector_state *conn_state, u32 level) 213 { 214 struct intel_connector *connector = to_intel_connector(conn_state->connector); 215 struct intel_panel *panel = &connector->panel; 216 217 if (panel->backlight.edp.intel.sdr_uses_aux) { 218 intel_dp_aux_hdr_set_aux_backlight(conn_state, level); 219 } else { 220 const u32 pwm_level = intel_backlight_level_to_pwm(connector, level); 221 222 intel_backlight_set_pwm_level(conn_state, pwm_level); 223 } 224 } 225 226 static void 227 intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state, 228 const struct drm_connector_state *conn_state, u32 level) 229 { 230 struct intel_connector *connector = to_intel_connector(conn_state->connector); 231 struct intel_panel *panel = &connector->panel; 232 struct drm_i915_private *i915 = to_i915(connector->base.dev); 233 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 234 int ret; 235 u8 old_ctrl, ctrl; 236 237 intel_dp_wait_source_oui(intel_dp); 238 239 ret = drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &old_ctrl); 240 if (ret != 1) { 241 drm_err(&i915->drm, "Failed to read current backlight control mode: %d\n", ret); 242 return; 243 } 244 245 ctrl = old_ctrl; 246 if (panel->backlight.edp.intel.sdr_uses_aux) { 247 ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE; 248 intel_dp_aux_hdr_set_aux_backlight(conn_state, level); 249 } else { 250 u32 pwm_level = intel_backlight_level_to_pwm(connector, level); 251 252 panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level); 253 254 ctrl &= ~INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE; 255 } 256 257 if (ctrl != old_ctrl) 258 if (drm_dp_dpcd_writeb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, ctrl) != 1) 259 drm_err(&i915->drm, "Failed to configure DPCD brightness controls\n"); 260 } 261 262 static void 263 intel_dp_aux_hdr_disable_backlight(const struct drm_connector_state *conn_state, u32 level) 264 { 265 struct intel_connector *connector = to_intel_connector(conn_state->connector); 266 struct intel_panel *panel = &connector->panel; 267 268 /* Nothing to do for AUX based backlight controls */ 269 if (panel->backlight.edp.intel.sdr_uses_aux) 270 return; 271 272 /* Note we want the actual pwm_level to be 0, regardless of pwm_min */ 273 panel->backlight.pwm_funcs->disable(conn_state, intel_backlight_invert_pwm_level(connector, 0)); 274 } 275 276 static int 277 intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pipe) 278 { 279 struct drm_i915_private *i915 = to_i915(connector->base.dev); 280 struct intel_panel *panel = &connector->panel; 281 struct drm_luminance_range_info *luminance_range = 282 &connector->base.display_info.luminance_range; 283 int ret; 284 285 if (panel->backlight.edp.intel.sdr_uses_aux) { 286 drm_dbg_kms(&i915->drm, "SDR backlight is controlled through DPCD\n"); 287 } else { 288 drm_dbg_kms(&i915->drm, "SDR backlight is controlled through PWM\n"); 289 290 ret = panel->backlight.pwm_funcs->setup(connector, pipe); 291 if (ret < 0) { 292 drm_err(&i915->drm, 293 "Failed to setup SDR backlight controls through PWM: %d\n", ret); 294 return ret; 295 } 296 } 297 298 if (luminance_range->max_luminance) { 299 panel->backlight.max = luminance_range->max_luminance; 300 panel->backlight.min = luminance_range->min_luminance; 301 } else { 302 panel->backlight.max = 512; 303 panel->backlight.min = 0; 304 } 305 306 drm_dbg_kms(&i915->drm, "Using backlight range %d..%d\n", panel->backlight.min, 307 panel->backlight.max); 308 309 panel->backlight.level = intel_dp_aux_hdr_get_backlight(connector, pipe); 310 panel->backlight.enabled = panel->backlight.level != 0; 311 312 return 0; 313 } 314 315 /* VESA backlight callbacks */ 316 static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, enum pipe unused) 317 { 318 return connector->panel.backlight.level; 319 } 320 321 static void 322 intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state, u32 level) 323 { 324 struct intel_connector *connector = to_intel_connector(conn_state->connector); 325 struct intel_panel *panel = &connector->panel; 326 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 327 328 if (!panel->backlight.edp.vesa.info.aux_set) { 329 const u32 pwm_level = intel_backlight_level_to_pwm(connector, level); 330 331 intel_backlight_set_pwm_level(conn_state, pwm_level); 332 } 333 334 drm_edp_backlight_set_level(&intel_dp->aux, &panel->backlight.edp.vesa.info, level); 335 } 336 337 static void 338 intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, 339 const struct drm_connector_state *conn_state, u32 level) 340 { 341 struct intel_connector *connector = to_intel_connector(conn_state->connector); 342 struct intel_panel *panel = &connector->panel; 343 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 344 345 if (!panel->backlight.edp.vesa.info.aux_enable) { 346 u32 pwm_level; 347 348 if (!panel->backlight.edp.vesa.info.aux_set) 349 pwm_level = intel_backlight_level_to_pwm(connector, level); 350 else 351 pwm_level = intel_backlight_invert_pwm_level(connector, 352 panel->backlight.pwm_level_max); 353 354 panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level); 355 } 356 357 drm_edp_backlight_enable(&intel_dp->aux, &panel->backlight.edp.vesa.info, level); 358 } 359 360 static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state *old_conn_state, 361 u32 level) 362 { 363 struct intel_connector *connector = to_intel_connector(old_conn_state->connector); 364 struct intel_panel *panel = &connector->panel; 365 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 366 367 drm_edp_backlight_disable(&intel_dp->aux, &panel->backlight.edp.vesa.info); 368 369 if (!panel->backlight.edp.vesa.info.aux_enable) 370 panel->backlight.pwm_funcs->disable(old_conn_state, 371 intel_backlight_invert_pwm_level(connector, 0)); 372 } 373 374 static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, enum pipe pipe) 375 { 376 struct intel_dp *intel_dp = intel_attached_dp(connector); 377 struct intel_panel *panel = &connector->panel; 378 struct drm_i915_private *i915 = dp_to_i915(intel_dp); 379 u16 current_level; 380 u8 current_mode; 381 int ret; 382 383 ret = drm_edp_backlight_init(&intel_dp->aux, &panel->backlight.edp.vesa.info, 384 panel->vbt.backlight.pwm_freq_hz, intel_dp->edp_dpcd, 385 ¤t_level, ¤t_mode); 386 if (ret < 0) 387 return ret; 388 389 if (!panel->backlight.edp.vesa.info.aux_set || !panel->backlight.edp.vesa.info.aux_enable) { 390 ret = panel->backlight.pwm_funcs->setup(connector, pipe); 391 if (ret < 0) { 392 drm_err(&i915->drm, 393 "Failed to setup PWM backlight controls for eDP backlight: %d\n", 394 ret); 395 return ret; 396 } 397 } 398 399 if (panel->backlight.edp.vesa.info.aux_set) { 400 panel->backlight.max = panel->backlight.edp.vesa.info.max; 401 panel->backlight.min = 0; 402 if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { 403 panel->backlight.level = current_level; 404 panel->backlight.enabled = panel->backlight.level != 0; 405 } else { 406 panel->backlight.level = panel->backlight.max; 407 panel->backlight.enabled = false; 408 } 409 } else { 410 panel->backlight.max = panel->backlight.pwm_level_max; 411 panel->backlight.min = panel->backlight.pwm_level_min; 412 if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_PWM) { 413 panel->backlight.level = panel->backlight.pwm_funcs->get(connector, pipe); 414 panel->backlight.enabled = panel->backlight.pwm_enabled; 415 } else { 416 panel->backlight.level = panel->backlight.max; 417 panel->backlight.enabled = false; 418 } 419 } 420 421 return 0; 422 } 423 424 static bool 425 intel_dp_aux_supports_vesa_backlight(struct intel_connector *connector) 426 { 427 struct intel_dp *intel_dp = intel_attached_dp(connector); 428 struct drm_i915_private *i915 = dp_to_i915(intel_dp); 429 430 if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) { 431 drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n"); 432 return true; 433 } 434 return false; 435 } 436 437 static const struct intel_panel_bl_funcs intel_dp_hdr_bl_funcs = { 438 .setup = intel_dp_aux_hdr_setup_backlight, 439 .enable = intel_dp_aux_hdr_enable_backlight, 440 .disable = intel_dp_aux_hdr_disable_backlight, 441 .set = intel_dp_aux_hdr_set_backlight, 442 .get = intel_dp_aux_hdr_get_backlight, 443 }; 444 445 static const struct intel_panel_bl_funcs intel_dp_vesa_bl_funcs = { 446 .setup = intel_dp_aux_vesa_setup_backlight, 447 .enable = intel_dp_aux_vesa_enable_backlight, 448 .disable = intel_dp_aux_vesa_disable_backlight, 449 .set = intel_dp_aux_vesa_set_backlight, 450 .get = intel_dp_aux_vesa_get_backlight, 451 }; 452 453 int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector) 454 { 455 struct drm_device *dev = connector->base.dev; 456 struct intel_panel *panel = &connector->panel; 457 struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder); 458 struct drm_i915_private *i915 = dp_to_i915(intel_dp); 459 bool try_intel_interface = false, try_vesa_interface = false; 460 461 /* Check the VBT and user's module parameters to figure out which 462 * interfaces to probe 463 */ 464 switch (i915->params.enable_dpcd_backlight) { 465 case INTEL_DP_AUX_BACKLIGHT_OFF: 466 return -ENODEV; 467 case INTEL_DP_AUX_BACKLIGHT_AUTO: 468 switch (panel->vbt.backlight.type) { 469 case INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE: 470 try_vesa_interface = true; 471 break; 472 case INTEL_BACKLIGHT_DISPLAY_DDI: 473 try_intel_interface = true; 474 break; 475 default: 476 return -ENODEV; 477 } 478 break; 479 case INTEL_DP_AUX_BACKLIGHT_ON: 480 if (panel->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE) 481 try_intel_interface = true; 482 483 try_vesa_interface = true; 484 break; 485 case INTEL_DP_AUX_BACKLIGHT_FORCE_VESA: 486 try_vesa_interface = true; 487 break; 488 case INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL: 489 try_intel_interface = true; 490 break; 491 } 492 493 /* 494 * Since Intel has their own backlight control interface, the majority of machines out there 495 * using DPCD backlight controls with Intel GPUs will be using this interface as opposed to 496 * the VESA interface. However, other GPUs (such as Nvidia's) will always use the VESA 497 * interface. This means that there's quite a number of panels out there that will advertise 498 * support for both interfaces, primarily systems with Intel/Nvidia hybrid GPU setups. 499 * 500 * There's a catch to this though: on many panels that advertise support for both 501 * interfaces, the VESA backlight interface will stop working once we've programmed the 502 * panel with Intel's OUI - which is also required for us to be able to detect Intel's 503 * backlight interface at all. This means that the only sensible way for us to detect both 504 * interfaces is to probe for Intel's first, and VESA's second. 505 */ 506 if (try_intel_interface && intel_dp_aux_supports_hdr_backlight(connector)) { 507 drm_dbg_kms(dev, "Using Intel proprietary eDP backlight controls\n"); 508 panel->backlight.funcs = &intel_dp_hdr_bl_funcs; 509 return 0; 510 } 511 512 if (try_vesa_interface && intel_dp_aux_supports_vesa_backlight(connector)) { 513 drm_dbg_kms(dev, "Using VESA eDP backlight controls\n"); 514 panel->backlight.funcs = &intel_dp_vesa_bl_funcs; 515 return 0; 516 } 517 518 return -ENODEV; 519 } 520