xref: /linux/drivers/gpu/drm/i915/display/intel_alpm.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright 2024, Intel Corporation.
4  */
5 
6 #include <linux/debugfs.h>
7 
8 #include <drm/drm_print.h>
9 
10 #include "intel_alpm.h"
11 #include "intel_crtc.h"
12 #include "intel_de.h"
13 #include "intel_display_types.h"
14 #include "intel_dp.h"
15 #include "intel_dp_aux.h"
16 #include "intel_psr.h"
17 #include "intel_psr_regs.h"
18 
19 #define SILENCE_PERIOD_MIN_TIME	80
20 #define SILENCE_PERIOD_MAX_TIME	180
21 #define SILENCE_PERIOD_TIME	(SILENCE_PERIOD_MIN_TIME +	\
22 				(SILENCE_PERIOD_MAX_TIME -	\
23 				 SILENCE_PERIOD_MIN_TIME) / 2)
24 
25 #define LFPS_CYCLE_COUNT 10
26 
27 bool intel_alpm_aux_wake_supported(struct intel_dp *intel_dp)
28 {
29 	return intel_dp->alpm_dpcd & DP_ALPM_CAP;
30 }
31 
32 bool intel_alpm_aux_less_wake_supported(struct intel_dp *intel_dp)
33 {
34 	return intel_dp->alpm_dpcd & DP_ALPM_AUX_LESS_CAP;
35 }
36 
37 bool intel_alpm_is_alpm_aux_less(struct intel_dp *intel_dp,
38 				 const struct intel_crtc_state *crtc_state)
39 {
40 	return intel_psr_needs_alpm_aux_less(intel_dp, crtc_state) ||
41 		(crtc_state->has_lobf && intel_alpm_aux_less_wake_supported(intel_dp));
42 }
43 
44 void intel_alpm_init(struct intel_dp *intel_dp)
45 {
46 	u8 dpcd;
47 
48 	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_RECEIVER_ALPM_CAP, &dpcd) < 0)
49 		return;
50 
51 	intel_dp->alpm_dpcd = dpcd;
52 	mutex_init(&intel_dp->alpm_parameters.lock);
53 }
54 
55 static int get_silence_period_symbols(const struct intel_crtc_state *crtc_state)
56 {
57 	return SILENCE_PERIOD_TIME * intel_dp_link_symbol_clock(crtc_state->port_clock) /
58 		1000 / 1000;
59 }
60 
61 static int get_lfps_cycle_min_max_time(const struct intel_crtc_state *crtc_state,
62 				       int *min, int *max)
63 {
64 	if (crtc_state->port_clock < 540000) {
65 		*min = 65 * LFPS_CYCLE_COUNT;
66 		*max = 75 * LFPS_CYCLE_COUNT;
67 	} else if (crtc_state->port_clock <= 810000) {
68 		*min = 140;
69 		*max = 800;
70 	} else {
71 		*min = *max = -1;
72 		return -1;
73 	}
74 
75 	return 0;
76 }
77 
78 static int get_lfps_cycle_time(const struct intel_crtc_state *crtc_state)
79 {
80 	int tlfps_cycle_min, tlfps_cycle_max, ret;
81 
82 	ret = get_lfps_cycle_min_max_time(crtc_state, &tlfps_cycle_min,
83 					  &tlfps_cycle_max);
84 	if (ret)
85 		return ret;
86 
87 	return tlfps_cycle_min +  (tlfps_cycle_max - tlfps_cycle_min) / 2;
88 }
89 
90 static int get_lfps_half_cycle_clocks(const struct intel_crtc_state *crtc_state)
91 {
92 	int lfps_cycle_time = get_lfps_cycle_time(crtc_state);
93 
94 	if (lfps_cycle_time < 0)
95 		return -1;
96 
97 	return lfps_cycle_time * crtc_state->port_clock / 1000 / 1000 / (2 * LFPS_CYCLE_COUNT);
98 }
99 
100 /*
101  * AUX-Less Wake Time = CEILING( ((PHY P2 to P0) + tLFPS_Period, Max+
102  * tSilence, Max+ tPHY Establishment + tCDS) / tline)
103  * For the "PHY P2 to P0" latency see the PHY Power Control page
104  * (PHY P2 to P0) : https://gfxspecs.intel.com/Predator/Home/Index/68965
105  * : 12 us
106  * The tLFPS_Period, Max term is 800ns
107  * The tSilence, Max term is 180ns
108  * The tPHY Establishment (a.k.a. t1) term is 50us
109  * The tCDS term is 1 or 2 times t2
110  * t2 = Number ML_PHY_LOCK * tML_PHY_LOCK
111  * Number ML_PHY_LOCK = ( 7 + CEILING( 6.5us / tML_PHY_LOCK ) + 1)
112  * Rounding up the 6.5us padding to the next ML_PHY_LOCK boundary and
113  * adding the "+ 1" term ensures all ML_PHY_LOCK sequences that start
114  * within the CDS period complete within the CDS period regardless of
115  * entry into the period
116  * tML_PHY_LOCK = TPS4 Length * ( 10 / (Link Rate in MHz) )
117  * TPS4 Length = 252 Symbols
118  */
119 static int _lnl_compute_aux_less_wake_time(const struct intel_crtc_state *crtc_state)
120 {
121 	int tphy2_p2_to_p0 = 12 * 1000;
122 	int t1 = 50 * 1000;
123 	int tps4 = 252;
124 	/* port_clock is link rate in 10kbit/s units */
125 	int tml_phy_lock = 1000 * 1000 * tps4 / crtc_state->port_clock;
126 	int num_ml_phy_lock = 7 + DIV_ROUND_UP(6500, tml_phy_lock) + 1;
127 	int t2 = num_ml_phy_lock * tml_phy_lock;
128 	int tcds = 1 * t2;
129 
130 	return DIV_ROUND_UP(tphy2_p2_to_p0 + get_lfps_cycle_time(crtc_state) +
131 			    SILENCE_PERIOD_TIME + t1 + tcds, 1000);
132 }
133 
134 static int
135 _lnl_compute_aux_less_alpm_params(struct intel_dp *intel_dp,
136 				  const struct intel_crtc_state *crtc_state)
137 {
138 	struct intel_display *display = to_intel_display(intel_dp);
139 	int aux_less_wake_time, aux_less_wake_lines, silence_period,
140 		lfps_half_cycle;
141 
142 	aux_less_wake_time =
143 		_lnl_compute_aux_less_wake_time(crtc_state);
144 	aux_less_wake_lines = intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode,
145 						       aux_less_wake_time);
146 	silence_period = get_silence_period_symbols(crtc_state);
147 
148 	lfps_half_cycle = get_lfps_half_cycle_clocks(crtc_state);
149 	if (lfps_half_cycle < 0)
150 		return false;
151 
152 	if (aux_less_wake_lines > ALPM_CTL_AUX_LESS_WAKE_TIME_MASK ||
153 	    silence_period > PORT_ALPM_CTL_SILENCE_PERIOD_MASK ||
154 	    lfps_half_cycle > PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION_MASK)
155 		return false;
156 
157 	if (display->params.psr_safest_params)
158 		aux_less_wake_lines = ALPM_CTL_AUX_LESS_WAKE_TIME_MASK;
159 
160 	intel_dp->alpm_parameters.aux_less_wake_lines = aux_less_wake_lines;
161 	intel_dp->alpm_parameters.silence_period_sym_clocks = silence_period;
162 	intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms = lfps_half_cycle;
163 
164 	return true;
165 }
166 
167 static bool _lnl_compute_alpm_params(struct intel_dp *intel_dp,
168 				     const struct intel_crtc_state *crtc_state)
169 {
170 	struct intel_display *display = to_intel_display(intel_dp);
171 	int check_entry_lines;
172 
173 	if (DISPLAY_VER(display) < 20)
174 		return true;
175 
176 	/* ALPM Entry Check = 2 + CEILING( 5us /tline ) */
177 	check_entry_lines = 2 +
178 		intel_usecs_to_scanlines(&crtc_state->hw.adjusted_mode, 5);
179 
180 	if (check_entry_lines > 15)
181 		return false;
182 
183 	if (!_lnl_compute_aux_less_alpm_params(intel_dp, crtc_state))
184 		return false;
185 
186 	if (display->params.psr_safest_params)
187 		check_entry_lines = 15;
188 
189 	intel_dp->alpm_parameters.check_entry_lines = check_entry_lines;
190 
191 	return true;
192 }
193 
194 /*
195  * IO wake time for DISPLAY_VER < 12 is not directly mentioned in Bspec. There
196  * are 50 us io wake time and 32 us fast wake time. Clearly preharge pulses are
197  * not (improperly) included in 32 us fast wake time. 50 us - 32 us = 18 us.
198  */
199 static int skl_io_buffer_wake_time(void)
200 {
201 	return 18;
202 }
203 
204 static int tgl_io_buffer_wake_time(void)
205 {
206 	return 10;
207 }
208 
209 static int io_buffer_wake_time(const struct intel_crtc_state *crtc_state)
210 {
211 	struct intel_display *display = to_intel_display(crtc_state);
212 
213 	if (DISPLAY_VER(display) >= 12)
214 		return tgl_io_buffer_wake_time();
215 	else
216 		return skl_io_buffer_wake_time();
217 }
218 
219 bool intel_alpm_compute_params(struct intel_dp *intel_dp,
220 			       const struct intel_crtc_state *crtc_state)
221 {
222 	struct intel_display *display = to_intel_display(intel_dp);
223 	int io_wake_lines, io_wake_time, fast_wake_lines, fast_wake_time;
224 	int tfw_exit_latency = 20; /* eDP spec */
225 	int phy_wake = 4;	   /* eDP spec */
226 	int preamble = 8;	   /* eDP spec */
227 	int precharge = intel_dp_aux_fw_sync_len(intel_dp) - preamble;
228 	u8 max_wake_lines;
229 
230 	io_wake_time = max(precharge, io_buffer_wake_time(crtc_state)) +
231 		preamble + phy_wake + tfw_exit_latency;
232 	fast_wake_time = precharge + preamble + phy_wake +
233 		tfw_exit_latency;
234 
235 	if (DISPLAY_VER(display) >= 20)
236 		max_wake_lines = 68;
237 	else if (DISPLAY_VER(display) >= 12)
238 		max_wake_lines = 12;
239 	else
240 		max_wake_lines = 8;
241 
242 	io_wake_lines = intel_usecs_to_scanlines(
243 		&crtc_state->hw.adjusted_mode, io_wake_time);
244 	fast_wake_lines = intel_usecs_to_scanlines(
245 		&crtc_state->hw.adjusted_mode, fast_wake_time);
246 
247 	if (io_wake_lines > max_wake_lines ||
248 	    fast_wake_lines > max_wake_lines)
249 		return false;
250 
251 	if (!_lnl_compute_alpm_params(intel_dp, crtc_state))
252 		return false;
253 
254 	if (display->params.psr_safest_params)
255 		io_wake_lines = fast_wake_lines = max_wake_lines;
256 
257 	/* According to Bspec lower limit should be set as 7 lines. */
258 	intel_dp->alpm_parameters.io_wake_lines = max(io_wake_lines, 7);
259 	intel_dp->alpm_parameters.fast_wake_lines = max(fast_wake_lines, 7);
260 
261 	return true;
262 }
263 
264 void intel_alpm_lobf_compute_config(struct intel_dp *intel_dp,
265 				    struct intel_crtc_state *crtc_state,
266 				    struct drm_connector_state *conn_state)
267 {
268 	struct intel_display *display = to_intel_display(intel_dp);
269 	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
270 	int waketime_in_lines, first_sdp_position;
271 	int context_latency, guardband;
272 
273 	if (intel_dp->alpm_parameters.lobf_disable_debug) {
274 		drm_dbg_kms(display->drm, "LOBF is disabled by debug flag\n");
275 		return;
276 	}
277 
278 	if (intel_dp->alpm_parameters.sink_alpm_error)
279 		return;
280 
281 	if (!intel_dp_is_edp(intel_dp))
282 		return;
283 
284 	if (DISPLAY_VER(display) < 20)
285 		return;
286 
287 	if (!intel_dp->as_sdp_supported)
288 		return;
289 
290 	if (crtc_state->has_psr)
291 		return;
292 
293 	if (crtc_state->vrr.vmin != crtc_state->vrr.vmax ||
294 	    crtc_state->vrr.vmin != crtc_state->vrr.flipline)
295 		return;
296 
297 	if (!(intel_alpm_aux_wake_supported(intel_dp) ||
298 	      intel_alpm_aux_less_wake_supported(intel_dp)))
299 		return;
300 
301 	if (!intel_alpm_compute_params(intel_dp, crtc_state))
302 		return;
303 
304 	context_latency = adjusted_mode->crtc_vblank_start - adjusted_mode->crtc_vdisplay;
305 	guardband = adjusted_mode->crtc_vtotal -
306 		    adjusted_mode->crtc_vdisplay - context_latency;
307 	first_sdp_position = adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vsync_start;
308 	if (intel_alpm_aux_less_wake_supported(intel_dp))
309 		waketime_in_lines = intel_dp->alpm_parameters.io_wake_lines;
310 	else
311 		waketime_in_lines = intel_dp->alpm_parameters.aux_less_wake_lines;
312 
313 	crtc_state->has_lobf = (context_latency + guardband) >
314 		(first_sdp_position + waketime_in_lines);
315 }
316 
317 static void lnl_alpm_configure(struct intel_dp *intel_dp,
318 			       const struct intel_crtc_state *crtc_state)
319 {
320 	struct intel_display *display = to_intel_display(intel_dp);
321 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
322 	u32 alpm_ctl;
323 
324 	if (DISPLAY_VER(display) < 20 || (!intel_psr_needs_alpm(intel_dp, crtc_state) &&
325 					  !crtc_state->has_lobf))
326 		return;
327 
328 	mutex_lock(&intel_dp->alpm_parameters.lock);
329 	/*
330 	 * Panel Replay on eDP is always using ALPM aux less. I.e. no need to
331 	 * check panel support at this point.
332 	 */
333 	if (intel_alpm_is_alpm_aux_less(intel_dp, crtc_state)) {
334 		alpm_ctl = ALPM_CTL_ALPM_ENABLE |
335 			ALPM_CTL_ALPM_AUX_LESS_ENABLE |
336 			ALPM_CTL_AUX_LESS_SLEEP_HOLD_TIME_50_SYMBOLS |
337 			ALPM_CTL_AUX_LESS_WAKE_TIME(intel_dp->alpm_parameters.aux_less_wake_lines);
338 
339 		if (intel_dp->as_sdp_supported) {
340 			u32 pr_alpm_ctl = PR_ALPM_CTL_ADAPTIVE_SYNC_SDP_POSITION_T1;
341 
342 			if (intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_CAPABILITY)] &
343 			    DP_PANEL_REPLAY_LINK_OFF_SUPPORTED_IN_PR_AFTER_ADAPTIVE_SYNC_SDP)
344 				pr_alpm_ctl |= PR_ALPM_CTL_ALLOW_LINK_OFF_BETWEEN_AS_SDP_AND_SU;
345 			if (!(intel_dp->pr_dpcd[INTEL_PR_DPCD_INDEX(DP_PANEL_REPLAY_CAP_CAPABILITY)] &
346 						DP_PANEL_REPLAY_ASYNC_VIDEO_TIMING_NOT_SUPPORTED_IN_PR))
347 				pr_alpm_ctl |= PR_ALPM_CTL_AS_SDP_TRANSMISSION_IN_ACTIVE_DISABLE;
348 
349 			intel_de_write(display, PR_ALPM_CTL(display, cpu_transcoder),
350 				       pr_alpm_ctl);
351 		}
352 
353 	} else {
354 		alpm_ctl = ALPM_CTL_EXTENDED_FAST_WAKE_ENABLE |
355 			ALPM_CTL_EXTENDED_FAST_WAKE_TIME(intel_dp->alpm_parameters.fast_wake_lines);
356 	}
357 
358 	if (crtc_state->has_lobf) {
359 		alpm_ctl |= ALPM_CTL_LOBF_ENABLE;
360 		drm_dbg_kms(display->drm, "Link off between frames (LOBF) enabled\n");
361 	}
362 
363 	alpm_ctl |= ALPM_CTL_ALPM_ENTRY_CHECK(intel_dp->alpm_parameters.check_entry_lines);
364 
365 	intel_de_write(display, ALPM_CTL(display, cpu_transcoder), alpm_ctl);
366 	mutex_unlock(&intel_dp->alpm_parameters.lock);
367 }
368 
369 void intel_alpm_configure(struct intel_dp *intel_dp,
370 			  const struct intel_crtc_state *crtc_state)
371 {
372 	lnl_alpm_configure(intel_dp, crtc_state);
373 	intel_dp->alpm_parameters.transcoder = crtc_state->cpu_transcoder;
374 }
375 
376 void intel_alpm_port_configure(struct intel_dp *intel_dp,
377 			       const struct intel_crtc_state *crtc_state)
378 {
379 	struct intel_display *display = to_intel_display(intel_dp);
380 	enum port port = dp_to_dig_port(intel_dp)->base.port;
381 	u32 alpm_ctl_val = 0, lfps_ctl_val = 0;
382 
383 	if (DISPLAY_VER(display) < 20)
384 		return;
385 
386 	if (intel_alpm_is_alpm_aux_less(intel_dp, crtc_state)) {
387 		alpm_ctl_val = PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE |
388 			PORT_ALPM_CTL_MAX_PHY_SWING_SETUP(15) |
389 			PORT_ALPM_CTL_MAX_PHY_SWING_HOLD(0) |
390 			PORT_ALPM_CTL_SILENCE_PERIOD(
391 				intel_dp->alpm_parameters.silence_period_sym_clocks);
392 		lfps_ctl_val = PORT_ALPM_LFPS_CTL_LFPS_CYCLE_COUNT(LFPS_CYCLE_COUNT) |
393 			PORT_ALPM_LFPS_CTL_LFPS_HALF_CYCLE_DURATION(
394 				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
395 			PORT_ALPM_LFPS_CTL_FIRST_LFPS_HALF_CYCLE_DURATION(
396 				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms) |
397 			PORT_ALPM_LFPS_CTL_LAST_LFPS_HALF_CYCLE_DURATION(
398 				intel_dp->alpm_parameters.lfps_half_cycle_num_of_syms);
399 	}
400 
401 	intel_de_write(display, PORT_ALPM_CTL(port), alpm_ctl_val);
402 
403 	intel_de_write(display, PORT_ALPM_LFPS_CTL(port), lfps_ctl_val);
404 }
405 
406 void intel_alpm_pre_plane_update(struct intel_atomic_state *state,
407 				 struct intel_crtc *crtc)
408 {
409 	struct intel_display *display = to_intel_display(state);
410 	const struct intel_crtc_state *crtc_state =
411 		intel_atomic_get_new_crtc_state(state, crtc);
412 	const struct intel_crtc_state *old_crtc_state =
413 		intel_atomic_get_old_crtc_state(state, crtc);
414 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
415 	struct intel_encoder *encoder;
416 
417 	if (DISPLAY_VER(display) < 20)
418 		return;
419 
420 	if (crtc_state->has_lobf || crtc_state->has_lobf == old_crtc_state->has_lobf)
421 		return;
422 
423 	for_each_intel_encoder_mask(display->drm, encoder,
424 				    crtc_state->uapi.encoder_mask) {
425 		struct intel_dp *intel_dp;
426 
427 		if (!intel_encoder_is_dp(encoder))
428 			continue;
429 
430 		intel_dp = enc_to_intel_dp(encoder);
431 
432 		if (!intel_dp_is_edp(intel_dp))
433 			continue;
434 
435 		if (old_crtc_state->has_lobf) {
436 			mutex_lock(&intel_dp->alpm_parameters.lock);
437 			intel_de_write(display, ALPM_CTL(display, cpu_transcoder), 0);
438 			drm_dbg_kms(display->drm, "Link off between frames (LOBF) disabled\n");
439 			mutex_unlock(&intel_dp->alpm_parameters.lock);
440 		}
441 	}
442 }
443 
444 void intel_alpm_enable_sink(struct intel_dp *intel_dp,
445 			    const struct intel_crtc_state *crtc_state)
446 {
447 	u8 val;
448 
449 	if (!intel_psr_needs_alpm(intel_dp, crtc_state) && !crtc_state->has_lobf)
450 		return;
451 
452 	val = DP_ALPM_ENABLE | DP_ALPM_LOCK_ERROR_IRQ_HPD_ENABLE;
453 
454 	if (crtc_state->has_panel_replay || (crtc_state->has_lobf &&
455 					     intel_alpm_aux_less_wake_supported(intel_dp)))
456 		val |= DP_ALPM_MODE_AUX_LESS;
457 
458 	drm_dp_dpcd_writeb(&intel_dp->aux, DP_RECEIVER_ALPM_CONFIG, val);
459 }
460 
461 void intel_alpm_post_plane_update(struct intel_atomic_state *state,
462 				  struct intel_crtc *crtc)
463 {
464 	struct intel_display *display = to_intel_display(state);
465 	const struct intel_crtc_state *crtc_state =
466 		intel_atomic_get_new_crtc_state(state, crtc);
467 	const struct intel_crtc_state *old_crtc_state =
468 		intel_atomic_get_old_crtc_state(state, crtc);
469 	struct intel_encoder *encoder;
470 
471 	if (crtc_state->has_psr || !crtc_state->has_lobf ||
472 	    crtc_state->has_lobf == old_crtc_state->has_lobf)
473 		return;
474 
475 	for_each_intel_encoder_mask(display->drm, encoder,
476 				    crtc_state->uapi.encoder_mask) {
477 		struct intel_dp *intel_dp;
478 
479 		if (!intel_encoder_is_dp(encoder))
480 			continue;
481 
482 		intel_dp = enc_to_intel_dp(encoder);
483 
484 		if (intel_dp_is_edp(intel_dp)) {
485 			intel_alpm_enable_sink(intel_dp, crtc_state);
486 			intel_alpm_configure(intel_dp, crtc_state);
487 		}
488 	}
489 }
490 
491 static int i915_edp_lobf_info_show(struct seq_file *m, void *data)
492 {
493 	struct intel_connector *connector = m->private;
494 	struct intel_display *display = to_intel_display(connector);
495 	struct drm_crtc *crtc;
496 	struct intel_crtc_state *crtc_state;
497 	enum transcoder cpu_transcoder;
498 	u32 alpm_ctl;
499 	int ret;
500 
501 	ret = drm_modeset_lock_single_interruptible(&display->drm->mode_config.connection_mutex);
502 	if (ret)
503 		return ret;
504 
505 	crtc = connector->base.state->crtc;
506 	if (connector->base.status != connector_status_connected || !crtc) {
507 		ret = -ENODEV;
508 		goto out;
509 	}
510 
511 	crtc_state = to_intel_crtc_state(crtc->state);
512 	cpu_transcoder = crtc_state->cpu_transcoder;
513 	alpm_ctl = intel_de_read(display, ALPM_CTL(display, cpu_transcoder));
514 	seq_printf(m, "LOBF status: %s\n", str_enabled_disabled(alpm_ctl & ALPM_CTL_LOBF_ENABLE));
515 	seq_printf(m, "Aux-wake alpm status: %s\n",
516 		   str_enabled_disabled(!(alpm_ctl & ALPM_CTL_ALPM_AUX_LESS_ENABLE)));
517 	seq_printf(m, "Aux-less alpm status: %s\n",
518 		   str_enabled_disabled(alpm_ctl & ALPM_CTL_ALPM_AUX_LESS_ENABLE));
519 out:
520 	drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
521 
522 	return ret;
523 }
524 
525 DEFINE_SHOW_ATTRIBUTE(i915_edp_lobf_info);
526 
527 static int
528 i915_edp_lobf_debug_get(void *data, u64 *val)
529 {
530 	struct intel_connector *connector = data;
531 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
532 
533 	*val = intel_dp->alpm_parameters.lobf_disable_debug;
534 
535 	return 0;
536 }
537 
538 static int
539 i915_edp_lobf_debug_set(void *data, u64 val)
540 {
541 	struct intel_connector *connector = data;
542 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
543 
544 	intel_dp->alpm_parameters.lobf_disable_debug = val;
545 
546 	return 0;
547 }
548 
549 DEFINE_SIMPLE_ATTRIBUTE(i915_edp_lobf_debug_fops,
550 			i915_edp_lobf_debug_get, i915_edp_lobf_debug_set,
551 			"%llu\n");
552 
553 void intel_alpm_lobf_debugfs_add(struct intel_connector *connector)
554 {
555 	struct intel_display *display = to_intel_display(connector);
556 	struct dentry *root = connector->base.debugfs_entry;
557 
558 	if (DISPLAY_VER(display) < 20 ||
559 	    connector->base.connector_type != DRM_MODE_CONNECTOR_eDP)
560 		return;
561 
562 	debugfs_create_file("i915_edp_lobf_debug", 0644, root,
563 			    connector, &i915_edp_lobf_debug_fops);
564 
565 	debugfs_create_file("i915_edp_lobf_info", 0444, root,
566 			    connector, &i915_edp_lobf_info_fops);
567 }
568 
569 void intel_alpm_disable(struct intel_dp *intel_dp)
570 {
571 	struct intel_display *display = to_intel_display(intel_dp);
572 	enum transcoder cpu_transcoder = intel_dp->alpm_parameters.transcoder;
573 
574 	if (DISPLAY_VER(display) < 20 || !intel_dp->alpm_dpcd)
575 		return;
576 
577 	mutex_lock(&intel_dp->alpm_parameters.lock);
578 
579 	intel_de_rmw(display, ALPM_CTL(display, cpu_transcoder),
580 		     ALPM_CTL_ALPM_ENABLE | ALPM_CTL_LOBF_ENABLE |
581 		     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
582 
583 	intel_de_rmw(display,
584 		     PORT_ALPM_CTL(cpu_transcoder),
585 		     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
586 
587 	drm_dbg_kms(display->drm, "Disabling ALPM\n");
588 	mutex_unlock(&intel_dp->alpm_parameters.lock);
589 }
590 
591 bool intel_alpm_get_error(struct intel_dp *intel_dp)
592 {
593 	struct intel_display *display = to_intel_display(intel_dp);
594 	struct drm_dp_aux *aux = &intel_dp->aux;
595 	u8 val;
596 	int r;
597 
598 	r = drm_dp_dpcd_readb(aux, DP_RECEIVER_ALPM_STATUS, &val);
599 	if (r != 1) {
600 		drm_err(display->drm, "Error reading ALPM status\n");
601 		return true;
602 	}
603 
604 	if (val & DP_ALPM_LOCK_TIMEOUT_ERROR) {
605 		drm_dbg_kms(display->drm, "ALPM lock timeout error\n");
606 
607 		/* Clearing error */
608 		drm_dp_dpcd_writeb(aux, DP_RECEIVER_ALPM_STATUS, val);
609 		return true;
610 	}
611 
612 	return false;
613 }
614