xref: /linux/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
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 <drm/drm_print.h>
38 
39 #include "intel_backlight.h"
40 #include "intel_display_core.h"
41 #include "intel_display_types.h"
42 #include "intel_dp.h"
43 #include "intel_dp_aux_backlight.h"
44 
45 /*
46  * DP AUX registers for Intel's proprietary HDR backlight interface. We define
47  * them here since we'll likely be the only driver to ever use these.
48  */
49 #define INTEL_EDP_HDR_TCON_CAP0                                        0x340
50 
51 #define INTEL_EDP_HDR_TCON_CAP1                                        0x341
52 # define INTEL_EDP_HDR_TCON_2084_DECODE_CAP                           BIT(0)
53 # define INTEL_EDP_HDR_TCON_2020_GAMUT_CAP                            BIT(1)
54 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_CAP                          BIT(2)
55 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_CAP                   BIT(3)
56 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP                       BIT(4)
57 # define INTEL_EDP_HDR_TCON_OPTIMIZATION_CAP                          BIT(5)
58 # define INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_CAP                       BIT(6)
59 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_CONVERSION_CAP        BIT(7)
60 
61 #define INTEL_EDP_HDR_TCON_CAP2                                        0x342
62 # define INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP                        BIT(0)
63 
64 #define INTEL_EDP_HDR_TCON_CAP3                                        0x343
65 
66 #define INTEL_EDP_HDR_GETSET_CTRL_PARAMS                               0x344
67 # define INTEL_EDP_HDR_TCON_2084_DECODE_ENABLE                        BIT(0)
68 # define INTEL_EDP_HDR_TCON_2020_GAMUT_ENABLE                         BIT(1)
69 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_ENABLE                       BIT(2)
70 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_ENABLE                BIT(3)
71 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE                     BIT(4)
72 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_ENABLE                BIT(5)
73 /* Bit 6 is reserved */
74 # define INTEL_EDP_HDR_TCON_SDP_OVERRIDE_AUX			      BIT(7)
75 
76 #define INTEL_EDP_HDR_CONTENT_LUMINANCE                                0x346
77 #define INTEL_EDP_HDR_PANEL_LUMINANCE_OVERRIDE                         0x34A
78 #define INTEL_EDP_SDR_LUMINANCE_LEVEL                                  0x352
79 #define INTEL_EDP_BRIGHTNESS_NITS_LSB                                  0x354
80 #define INTEL_EDP_BRIGHTNESS_NITS_MSB                                  0x355
81 #define INTEL_EDP_BRIGHTNESS_DELAY_FRAMES                              0x356
82 #define INTEL_EDP_BRIGHTNESS_PER_FRAME_STEPS                           0x357
83 
84 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_0                            0x358
85 # define INTEL_EDP_TCON_USAGE_MASK                             GENMASK(0, 3)
86 # define INTEL_EDP_TCON_USAGE_UNKNOWN                                    0x0
87 # define INTEL_EDP_TCON_USAGE_DESKTOP                                    0x1
88 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_MEDIA                          0x2
89 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_GAMING                         0x3
90 # define INTEL_EDP_TCON_POWER_MASK                                    BIT(4)
91 # define INTEL_EDP_TCON_POWER_DC                                    (0 << 4)
92 # define INTEL_EDP_TCON_POWER_AC                                    (1 << 4)
93 # define INTEL_EDP_TCON_OPTIMIZATION_STRENGTH_MASK             GENMASK(5, 7)
94 
95 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_1                            0x359
96 
97 enum intel_dp_aux_backlight_modparam {
98 	INTEL_DP_AUX_BACKLIGHT_AUTO = -1,
99 	INTEL_DP_AUX_BACKLIGHT_OFF = 0,
100 	INTEL_DP_AUX_BACKLIGHT_ON = 1,
101 	INTEL_DP_AUX_BACKLIGHT_FORCE_VESA = 2,
102 	INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL = 3,
103 };
104 
105 static bool is_intel_tcon_cap(const u8 tcon_cap[4])
106 {
107 	return tcon_cap[0] >= 1;
108 }
109 
110 /* Intel EDP backlight callbacks */
111 static bool
112 intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector)
113 {
114 	struct intel_display *display = to_intel_display(connector);
115 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
116 	struct drm_dp_aux *aux = &intel_dp->aux;
117 	struct intel_panel *panel = &connector->panel;
118 	int ret;
119 	u8 tcon_cap[4];
120 
121 	intel_dp_wait_source_oui(intel_dp);
122 
123 	ret = drm_dp_dpcd_read(aux, INTEL_EDP_HDR_TCON_CAP0, tcon_cap, sizeof(tcon_cap));
124 	if (ret != sizeof(tcon_cap))
125 		return false;
126 
127 	drm_dbg_kms(display->drm,
128 		    "[CONNECTOR:%d:%s] Detected %s HDR backlight interface version %d\n",
129 		    connector->base.base.id, connector->base.name,
130 		    is_intel_tcon_cap(tcon_cap) ? "Intel" : "unsupported", tcon_cap[0]);
131 
132 	if (!is_intel_tcon_cap(tcon_cap))
133 		return false;
134 
135 	if (!(tcon_cap[1] & INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP))
136 		return false;
137 
138 	/*
139 	 * If we don't have HDR static metadata there is no way to
140 	 * runtime detect used range for nits based control. For now
141 	 * do not use Intel proprietary eDP backlight control if we
142 	 * don't have this data in panel EDID. In case we find panel
143 	 * which supports only nits based control, but doesn't provide
144 	 * HDR static metadata we need to start maintaining table of
145 	 * ranges for such panels.
146 	 */
147 	if (display->params.enable_dpcd_backlight != INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL &&
148 	    !(connector->base.display_info.hdr_sink_metadata.hdmi_type1.metadata_type &
149 	      BIT(HDMI_STATIC_METADATA_TYPE1))) {
150 		drm_info(display->drm,
151 			 "[CONNECTOR:%d:%s] 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.\n",
152 			 connector->base.base.id, connector->base.name,
153 			 INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL);
154 		return false;
155 	}
156 
157 	panel->backlight.edp.intel_cap.sdr_uses_aux =
158 		tcon_cap[2] & INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP;
159 	panel->backlight.edp.intel_cap.supports_2084_decode =
160 		tcon_cap[1] & INTEL_EDP_HDR_TCON_2084_DECODE_CAP;
161 	panel->backlight.edp.intel_cap.supports_2020_gamut =
162 		tcon_cap[1] & INTEL_EDP_HDR_TCON_2020_GAMUT_CAP;
163 	panel->backlight.edp.intel_cap.supports_segmented_backlight =
164 		tcon_cap[1] & INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_CAP;
165 	panel->backlight.edp.intel_cap.supports_sdp_colorimetry =
166 		tcon_cap[1] & INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_CAP;
167 	panel->backlight.edp.intel_cap.supports_tone_mapping =
168 		tcon_cap[1] & INTEL_EDP_HDR_TCON_TONE_MAPPING_CAP;
169 
170 	return true;
171 }
172 
173 static u32
174 intel_dp_aux_hdr_get_backlight(struct intel_connector *connector, enum pipe pipe)
175 {
176 	struct intel_display *display = to_intel_display(connector);
177 	struct intel_panel *panel = &connector->panel;
178 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
179 	u8 tmp;
180 	u8 buf[2] = {};
181 
182 	if (drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &tmp) != 1) {
183 		drm_err(display->drm,
184 			"[CONNECTOR:%d:%s] Failed to read current backlight mode from DPCD\n",
185 			connector->base.base.id, connector->base.name);
186 		return 0;
187 	}
188 
189 	if (!(tmp & INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE)) {
190 		if (!panel->backlight.edp.intel_cap.sdr_uses_aux) {
191 			u32 pwm_level = panel->backlight.pwm_funcs->get(connector, pipe);
192 
193 			return intel_backlight_level_from_pwm(connector, pwm_level);
194 		}
195 
196 		/* Assume 100% brightness if backlight controls aren't enabled yet */
197 		return panel->backlight.max;
198 	}
199 
200 	if (drm_dp_dpcd_read(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf,
201 			     sizeof(buf)) != sizeof(buf)) {
202 		drm_err(display->drm,
203 			"[CONNECTOR:%d:%s] Failed to read brightness from DPCD\n",
204 			connector->base.base.id, connector->base.name);
205 		return 0;
206 	}
207 
208 	return (buf[1] << 8 | buf[0]);
209 }
210 
211 static void
212 intel_dp_aux_hdr_set_aux_backlight(const struct drm_connector_state *conn_state, u32 level)
213 {
214 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
215 	struct drm_device *dev = connector->base.dev;
216 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
217 	u8 buf[4] = {};
218 
219 	buf[0] = level & 0xFF;
220 	buf[1] = (level & 0xFF00) >> 8;
221 
222 	if (drm_dp_dpcd_write(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf,
223 			      sizeof(buf)) != sizeof(buf))
224 		drm_err(dev, "[CONNECTOR:%d:%s] Failed to write brightness level to DPCD\n",
225 			connector->base.base.id, connector->base.name);
226 }
227 
228 static void
229 intel_dp_aux_hdr_set_backlight(const struct drm_connector_state *conn_state, u32 level)
230 {
231 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
232 	struct intel_panel *panel = &connector->panel;
233 
234 	if (intel_dp_in_hdr_mode(conn_state) ||
235 	    panel->backlight.edp.intel_cap.sdr_uses_aux) {
236 		intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
237 	} else {
238 		const u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
239 
240 		intel_backlight_set_pwm_level(conn_state, pwm_level);
241 	}
242 }
243 
244 static void
245 intel_dp_aux_write_content_luminance(struct intel_connector *connector,
246 				     struct hdr_output_metadata *hdr_metadata)
247 {
248 	struct intel_display *display = to_intel_display(connector);
249 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
250 	int ret;
251 	u8 buf[4];
252 
253 	if (!intel_dp_has_gamut_metadata_dip(connector->encoder))
254 		return;
255 
256 	buf[0] = hdr_metadata->hdmi_metadata_type1.max_cll & 0xFF;
257 	buf[1] = (hdr_metadata->hdmi_metadata_type1.max_cll & 0xFF00) >> 8;
258 	buf[2] = hdr_metadata->hdmi_metadata_type1.max_fall & 0xFF;
259 	buf[3] = (hdr_metadata->hdmi_metadata_type1.max_fall & 0xFF00) >> 8;
260 
261 	ret = drm_dp_dpcd_write(&intel_dp->aux,
262 				INTEL_EDP_HDR_CONTENT_LUMINANCE,
263 				buf, sizeof(buf));
264 	if (ret < 0)
265 		drm_dbg_kms(display->drm,
266 			    "Content Luminance DPCD reg write failed, err:-%d\n",
267 			    ret);
268 }
269 
270 static void
271 intel_dp_aux_fill_hdr_tcon_params(const struct drm_connector_state *conn_state, u8 *ctrl)
272 {
273 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
274 	struct intel_panel *panel = &connector->panel;
275 	struct intel_display *display = to_intel_display(connector);
276 
277 	/*
278 	 * According to spec segmented backlight needs to be set whenever panel is in
279 	 * HDR mode.
280 	 */
281 	if (intel_dp_in_hdr_mode(conn_state)) {
282 		*ctrl |= INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_ENABLE;
283 		*ctrl |= INTEL_EDP_HDR_TCON_2084_DECODE_ENABLE;
284 	}
285 
286 	if (DISPLAY_VER(display) < 11)
287 		*ctrl &= ~INTEL_EDP_HDR_TCON_TONE_MAPPING_ENABLE;
288 
289 	if (panel->backlight.edp.intel_cap.supports_2020_gamut &&
290 	    (conn_state->colorspace == DRM_MODE_COLORIMETRY_BT2020_RGB ||
291 	     conn_state->colorspace == DRM_MODE_COLORIMETRY_BT2020_YCC ||
292 	     conn_state->colorspace == DRM_MODE_COLORIMETRY_BT2020_CYCC))
293 		*ctrl |= INTEL_EDP_HDR_TCON_2020_GAMUT_ENABLE;
294 
295 	if (panel->backlight.edp.intel_cap.supports_sdp_colorimetry &&
296 	    intel_dp_has_gamut_metadata_dip(connector->encoder))
297 		*ctrl |= INTEL_EDP_HDR_TCON_SDP_OVERRIDE_AUX;
298 	else
299 		*ctrl &= ~INTEL_EDP_HDR_TCON_SDP_OVERRIDE_AUX;
300 }
301 
302 static void
303 intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state,
304 				  const struct drm_connector_state *conn_state, u32 level)
305 {
306 	struct intel_display *display = to_intel_display(crtc_state);
307 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
308 	struct intel_panel *panel = &connector->panel;
309 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
310 	struct hdr_output_metadata *hdr_metadata;
311 	int ret;
312 	u8 old_ctrl, ctrl;
313 
314 	intel_dp_wait_source_oui(intel_dp);
315 
316 	ret = drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &old_ctrl);
317 	if (ret != 1) {
318 		drm_err(display->drm,
319 			"[CONNECTOR:%d:%s] Failed to read current backlight control mode: %d\n",
320 			connector->base.base.id, connector->base.name, ret);
321 		return;
322 	}
323 
324 	ctrl = old_ctrl;
325 	if (intel_dp_in_hdr_mode(conn_state) ||
326 	    panel->backlight.edp.intel_cap.sdr_uses_aux) {
327 		ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE;
328 
329 		intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
330 	} else {
331 		u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
332 
333 		panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level);
334 
335 		ctrl &= ~INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE;
336 	}
337 
338 	intel_dp_aux_fill_hdr_tcon_params(conn_state, &ctrl);
339 
340 	if (ctrl != old_ctrl &&
341 	    drm_dp_dpcd_writeb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, ctrl) != 1)
342 		drm_err(display->drm,
343 			"[CONNECTOR:%d:%s] Failed to configure DPCD brightness controls\n",
344 			connector->base.base.id, connector->base.name);
345 
346 	if (intel_dp_in_hdr_mode(conn_state)) {
347 		hdr_metadata = conn_state->hdr_output_metadata->data;
348 		intel_dp_aux_write_content_luminance(connector, hdr_metadata);
349 	}
350 }
351 
352 static void
353 intel_dp_aux_hdr_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
354 {
355 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
356 	struct intel_panel *panel = &connector->panel;
357 
358 	/* Nothing to do for AUX based backlight controls */
359 	if (panel->backlight.edp.intel_cap.sdr_uses_aux)
360 		return;
361 
362 	/* Note we want the actual pwm_level to be 0, regardless of pwm_min */
363 	panel->backlight.pwm_funcs->disable(conn_state, intel_backlight_invert_pwm_level(connector, 0));
364 }
365 
366 static const char *dpcd_vs_pwm_str(bool aux)
367 {
368 	return aux ? "DPCD" : "PWM";
369 }
370 
371 static void
372 intel_dp_aux_write_panel_luminance_override(struct intel_connector *connector)
373 {
374 	struct intel_display *display = to_intel_display(connector);
375 	struct intel_panel *panel = &connector->panel;
376 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
377 	int ret;
378 	u8 buf[4] = {};
379 
380 	buf[0] = panel->backlight.min & 0xFF;
381 	buf[1] = (panel->backlight.min & 0xFF00) >> 8;
382 	buf[2] = panel->backlight.max & 0xFF;
383 	buf[3] = (panel->backlight.max & 0xFF00) >> 8;
384 
385 	ret = drm_dp_dpcd_write(&intel_dp->aux,
386 				INTEL_EDP_HDR_PANEL_LUMINANCE_OVERRIDE,
387 				buf, sizeof(buf));
388 	if (ret < 0)
389 		drm_dbg_kms(display->drm,
390 			    "Panel Luminance DPCD reg write failed, err:-%d\n",
391 			    ret);
392 }
393 
394 static int
395 intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pipe)
396 {
397 	struct intel_display *display = to_intel_display(connector);
398 	struct intel_panel *panel = &connector->panel;
399 	struct drm_luminance_range_info *luminance_range =
400 		&connector->base.display_info.luminance_range;
401 	int ret;
402 
403 	drm_dbg_kms(display->drm,
404 		    "[CONNECTOR:%d:%s] SDR backlight is controlled through %s\n",
405 		    connector->base.base.id, connector->base.name,
406 		    dpcd_vs_pwm_str(panel->backlight.edp.intel_cap.sdr_uses_aux));
407 
408 	if (!panel->backlight.edp.intel_cap.sdr_uses_aux) {
409 		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
410 		if (ret < 0) {
411 			drm_err(display->drm,
412 				"[CONNECTOR:%d:%s] Failed to setup SDR backlight controls through PWM: %d\n",
413 				connector->base.base.id, connector->base.name, ret);
414 			return ret;
415 		}
416 	}
417 
418 	if (luminance_range->max_luminance) {
419 		panel->backlight.max = luminance_range->max_luminance;
420 		panel->backlight.min = luminance_range->min_luminance;
421 	} else {
422 		panel->backlight.max = 512;
423 		panel->backlight.min = 0;
424 	}
425 
426 	intel_dp_aux_write_panel_luminance_override(connector);
427 
428 	drm_dbg_kms(display->drm,
429 		    "[CONNECTOR:%d:%s] Using AUX HDR interface for backlight control (range %d..%d)\n",
430 		    connector->base.base.id, connector->base.name,
431 		    panel->backlight.min, panel->backlight.max);
432 
433 	panel->backlight.level = intel_dp_aux_hdr_get_backlight(connector, pipe);
434 	panel->backlight.enabled = panel->backlight.level != 0;
435 
436 	return 0;
437 }
438 
439 /* VESA backlight callbacks */
440 static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, enum pipe unused)
441 {
442 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
443 	struct intel_panel *panel = &connector->panel;
444 	u8 buf[3];
445 	u32 val = 0;
446 	int ret;
447 
448 	if (panel->backlight.edp.vesa.luminance_control_support) {
449 		ret = drm_dp_dpcd_read(&intel_dp->aux, DP_EDP_PANEL_TARGET_LUMINANCE_VALUE, buf,
450 				       sizeof(buf));
451 		if (ret < 0) {
452 			drm_err(intel_dp->aux.drm_dev,
453 				"[CONNECTOR:%d:%s] Failed to read Luminance from DPCD\n",
454 				connector->base.base.id, connector->base.name);
455 			return 0;
456 		}
457 
458 		val |= buf[0] | buf[1] << 8 | buf[2] << 16;
459 		return val / 1000;
460 	}
461 
462 	return connector->panel.backlight.level;
463 }
464 
465 static void
466 intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state, u32 level)
467 {
468 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
469 	struct intel_panel *panel = &connector->panel;
470 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
471 
472 	if (!panel->backlight.edp.vesa.info.aux_set) {
473 		const u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
474 
475 		intel_backlight_set_pwm_level(conn_state, pwm_level);
476 	}
477 
478 	drm_edp_backlight_set_level(&intel_dp->aux, &panel->backlight.edp.vesa.info, level);
479 }
480 
481 static void
482 intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state,
483 				   const struct drm_connector_state *conn_state, u32 level)
484 {
485 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
486 	struct intel_panel *panel = &connector->panel;
487 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
488 
489 	if (!panel->backlight.edp.vesa.info.aux_enable) {
490 		u32 pwm_level;
491 
492 		if (!panel->backlight.edp.vesa.info.aux_set)
493 			pwm_level = intel_backlight_level_to_pwm(connector, level);
494 		else
495 			pwm_level = intel_backlight_invert_pwm_level(connector,
496 								     panel->backlight.pwm_level_max);
497 
498 		panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level);
499 	}
500 
501 	drm_edp_backlight_enable(&intel_dp->aux, &panel->backlight.edp.vesa.info, level);
502 }
503 
504 static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state *old_conn_state,
505 						u32 level)
506 {
507 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
508 	struct intel_panel *panel = &connector->panel;
509 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
510 
511 	drm_edp_backlight_disable(&intel_dp->aux, &panel->backlight.edp.vesa.info);
512 
513 	if (!panel->backlight.edp.vesa.info.aux_enable)
514 		panel->backlight.pwm_funcs->disable(old_conn_state,
515 						    intel_backlight_invert_pwm_level(connector, 0));
516 }
517 
518 static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, enum pipe pipe)
519 {
520 	struct intel_display *display = to_intel_display(connector);
521 	struct drm_luminance_range_info *luminance_range =
522 		&connector->base.display_info.luminance_range;
523 	struct intel_dp *intel_dp = intel_attached_dp(connector);
524 	struct intel_panel *panel = &connector->panel;
525 	u32 current_level;
526 	u8 current_mode;
527 	int ret;
528 
529 	ret = drm_edp_backlight_init(&intel_dp->aux, &panel->backlight.edp.vesa.info,
530 				     luminance_range->max_luminance,
531 				     panel->vbt.backlight.pwm_freq_hz,
532 				     intel_dp->edp_dpcd, &current_level, &current_mode,
533 				     panel->backlight.edp.vesa.luminance_control_support);
534 	if (ret < 0)
535 		return ret;
536 
537 	drm_dbg_kms(display->drm,
538 		    "[CONNECTOR:%d:%s] AUX VESA backlight enable is controlled through %s\n",
539 		    connector->base.base.id, connector->base.name,
540 		    dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_enable));
541 	drm_dbg_kms(display->drm,
542 		    "[CONNECTOR:%d:%s] AUX VESA backlight level is controlled through %s\n",
543 		    connector->base.base.id, connector->base.name,
544 		    dpcd_vs_pwm_str(panel->backlight.edp.vesa.info.aux_set));
545 
546 	if (!panel->backlight.edp.vesa.info.aux_set ||
547 	    !panel->backlight.edp.vesa.info.aux_enable) {
548 		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
549 		if (ret < 0) {
550 			drm_err(display->drm,
551 				"[CONNECTOR:%d:%s] Failed to setup PWM backlight controls for eDP backlight: %d\n",
552 				connector->base.base.id, connector->base.name, ret);
553 			return ret;
554 		}
555 	}
556 
557 	if (panel->backlight.edp.vesa.info.luminance_set) {
558 		if (luminance_range->max_luminance) {
559 			panel->backlight.max = panel->backlight.edp.vesa.info.max;
560 			panel->backlight.min = luminance_range->min_luminance;
561 		} else {
562 			panel->backlight.max = 512;
563 			panel->backlight.min = 0;
564 		}
565 		panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, 0);
566 		panel->backlight.enabled = panel->backlight.level != 0;
567 		drm_dbg_kms(display->drm,
568 			    "[CONNECTOR:%d:%s] AUX VESA Nits backlight level is controlled through DPCD\n",
569 			    connector->base.base.id, connector->base.name);
570 	} else if (panel->backlight.edp.vesa.info.aux_set) {
571 		panel->backlight.max = panel->backlight.edp.vesa.info.max;
572 		panel->backlight.min = 0;
573 		if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
574 			panel->backlight.level = current_level;
575 			panel->backlight.enabled = panel->backlight.level != 0;
576 		} else {
577 			panel->backlight.level = panel->backlight.max;
578 			panel->backlight.enabled = false;
579 		}
580 	} else {
581 		panel->backlight.max = panel->backlight.pwm_level_max;
582 		panel->backlight.min = panel->backlight.pwm_level_min;
583 		if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_PWM) {
584 			panel->backlight.level =
585 				panel->backlight.pwm_funcs->get(connector, pipe);
586 			panel->backlight.enabled = panel->backlight.pwm_enabled;
587 		} else {
588 			panel->backlight.level = panel->backlight.max;
589 			panel->backlight.enabled = false;
590 		}
591 	}
592 
593 	drm_dbg_kms(display->drm,
594 		    "[CONNECTOR:%d:%s] Using AUX VESA interface for backlight control\n",
595 		    connector->base.base.id, connector->base.name);
596 
597 	return 0;
598 }
599 
600 static bool
601 intel_dp_aux_supports_vesa_backlight(struct intel_connector *connector)
602 {
603 	struct intel_display *display = to_intel_display(connector);
604 	struct intel_dp *intel_dp = intel_attached_dp(connector);
605 	struct intel_panel *panel = &connector->panel;
606 
607 	if ((intel_dp->edp_dpcd[3] & DP_EDP_PANEL_LUMINANCE_CONTROL_CAPABLE) &&
608 	    (intel_dp->edp_dpcd[3] & DP_EDP_SMOOTH_BRIGHTNESS_CAPABLE)) {
609 		drm_dbg_kms(display->drm,
610 			    "[CONNECTOR:%d:%s] AUX Luminance Based Backlight Control Supported!\n",
611 			    connector->base.base.id, connector->base.name);
612 		panel->backlight.edp.vesa.luminance_control_support = true;
613 		return true;
614 	}
615 
616 	if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
617 		drm_dbg_kms(display->drm,
618 			    "[CONNECTOR:%d:%s] AUX Backlight Control Supported!\n",
619 			    connector->base.base.id, connector->base.name);
620 		return true;
621 	}
622 	return false;
623 }
624 
625 static const struct intel_panel_bl_funcs intel_dp_hdr_bl_funcs = {
626 	.setup = intel_dp_aux_hdr_setup_backlight,
627 	.enable = intel_dp_aux_hdr_enable_backlight,
628 	.disable = intel_dp_aux_hdr_disable_backlight,
629 	.set = intel_dp_aux_hdr_set_backlight,
630 	.get = intel_dp_aux_hdr_get_backlight,
631 };
632 
633 static const struct intel_panel_bl_funcs intel_dp_vesa_bl_funcs = {
634 	.setup = intel_dp_aux_vesa_setup_backlight,
635 	.enable = intel_dp_aux_vesa_enable_backlight,
636 	.disable = intel_dp_aux_vesa_disable_backlight,
637 	.set = intel_dp_aux_vesa_set_backlight,
638 	.get = intel_dp_aux_vesa_get_backlight,
639 };
640 
641 int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
642 {
643 	struct intel_display *display = to_intel_display(connector);
644 	struct intel_dp *intel_dp = intel_attached_dp(connector);
645 	struct drm_device *dev = connector->base.dev;
646 	struct intel_panel *panel = &connector->panel;
647 	bool try_intel_interface = false, try_vesa_interface = false;
648 
649 	/* Check the VBT and user's module parameters to figure out which
650 	 * interfaces to probe
651 	 */
652 	switch (display->params.enable_dpcd_backlight) {
653 	case INTEL_DP_AUX_BACKLIGHT_OFF:
654 		return -ENODEV;
655 	case INTEL_DP_AUX_BACKLIGHT_AUTO:
656 		switch (panel->vbt.backlight.type) {
657 		case INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE:
658 			try_vesa_interface = true;
659 			break;
660 		case INTEL_BACKLIGHT_DISPLAY_DDI:
661 			try_intel_interface = true;
662 			break;
663 		default:
664 			return -ENODEV;
665 		}
666 		break;
667 	case INTEL_DP_AUX_BACKLIGHT_ON:
668 		if (panel->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE)
669 			try_intel_interface = true;
670 
671 		try_vesa_interface = true;
672 		break;
673 	case INTEL_DP_AUX_BACKLIGHT_FORCE_VESA:
674 		try_vesa_interface = true;
675 		break;
676 	case INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL:
677 		try_intel_interface = true;
678 		break;
679 	}
680 
681 	/* For eDP 1.5 and above we are supposed to use VESA interface for brightness control */
682 	if (intel_dp->edp_dpcd[0] >= DP_EDP_15)
683 		try_vesa_interface = true;
684 
685 	/*
686 	 * Since Intel has their own backlight control interface, the majority of machines out there
687 	 * using DPCD backlight controls with Intel GPUs will be using this interface as opposed to
688 	 * the VESA interface. However, other GPUs (such as Nvidia's) will always use the VESA
689 	 * interface. This means that there's quite a number of panels out there that will advertise
690 	 * support for both interfaces, primarily systems with Intel/Nvidia hybrid GPU setups.
691 	 *
692 	 * There's a catch to this though: on many panels that advertise support for both
693 	 * interfaces, the VESA backlight interface will stop working once we've programmed the
694 	 * panel with Intel's OUI - which is also required for us to be able to detect Intel's
695 	 * backlight interface at all. This means that the only sensible way for us to detect both
696 	 * interfaces is to probe for Intel's first, and VESA's second.
697 	 */
698 	if (try_intel_interface && intel_dp_aux_supports_hdr_backlight(connector) &&
699 	    intel_dp->edp_dpcd[0] <= DP_EDP_14b) {
700 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Using Intel proprietary eDP backlight controls\n",
701 			    connector->base.base.id, connector->base.name);
702 		panel->backlight.funcs = &intel_dp_hdr_bl_funcs;
703 		return 0;
704 	}
705 
706 	if (try_vesa_interface && intel_dp_aux_supports_vesa_backlight(connector)) {
707 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Using VESA eDP backlight controls\n",
708 			    connector->base.base.id, connector->base.name);
709 		panel->backlight.funcs = &intel_dp_vesa_bl_funcs;
710 		return 0;
711 	}
712 
713 	return -ENODEV;
714 }
715