1/*	$NetBSD: intel_tc.c,v 1.3 2021/12/19 11:49:11 riastradh Exp $	*/
2
3// SPDX-License-Identifier: MIT
4/*
5 * Copyright �� 2019 Intel Corporation
6 */
7
8#include <sys/cdefs.h>
9__KERNEL_RCSID(0, "$NetBSD: intel_tc.c,v 1.3 2021/12/19 11:49:11 riastradh Exp $");
10
11#include "i915_drv.h"
12#include "intel_display.h"
13#include "intel_display_types.h"
14#include "intel_dp_mst.h"
15#include "intel_tc.h"
16
17#include <linux/nbsd-namespace.h>
18
19static const char *tc_port_mode_name(enum tc_port_mode mode)
20{
21	static const char * const names[] = {
22		[TC_PORT_TBT_ALT] = "tbt-alt",
23		[TC_PORT_DP_ALT] = "dp-alt",
24		[TC_PORT_LEGACY] = "legacy",
25	};
26
27	if (WARN_ON(mode >= ARRAY_SIZE(names)))
28		mode = TC_PORT_TBT_ALT;
29
30	return names[mode];
31}
32
33static void
34tc_port_load_fia_params(struct drm_i915_private *i915,
35			struct intel_digital_port *dig_port)
36{
37	enum port port = dig_port->base.port;
38	enum tc_port tc_port = intel_port_to_tc(i915, port);
39	u32 modular_fia;
40
41	if (INTEL_INFO(i915)->display.has_modular_fia) {
42		modular_fia = intel_uncore_read(&i915->uncore,
43						PORT_TX_DFLEXDPSP(FIA1));
44		modular_fia &= MODULAR_FIA_MASK;
45	} else {
46		modular_fia = 0;
47	}
48
49	/*
50	 * Each Modular FIA instance houses 2 TC ports. In SOC that has more
51	 * than two TC ports, there are multiple instances of Modular FIA.
52	 */
53	if (modular_fia) {
54		dig_port->tc_phy_fia = tc_port / 2;
55		dig_port->tc_phy_fia_idx = tc_port % 2;
56	} else {
57		dig_port->tc_phy_fia = FIA1;
58		dig_port->tc_phy_fia_idx = tc_port;
59	}
60}
61
62u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
63{
64	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
65	struct intel_uncore *uncore = &i915->uncore;
66	u32 lane_mask;
67
68	lane_mask = intel_uncore_read(uncore,
69				      PORT_TX_DFLEXDPSP(dig_port->tc_phy_fia));
70
71	WARN_ON(lane_mask == 0xffffffff);
72
73	lane_mask &= DP_LANE_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx);
74	return lane_mask >> DP_LANE_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
75}
76
77u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port)
78{
79	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
80	struct intel_uncore *uncore = &i915->uncore;
81	u32 pin_mask;
82
83	pin_mask = intel_uncore_read(uncore,
84				     PORT_TX_DFLEXPA1(dig_port->tc_phy_fia));
85
86	WARN_ON(pin_mask == 0xffffffff);
87
88	return (pin_mask & DP_PIN_ASSIGNMENT_MASK(dig_port->tc_phy_fia_idx)) >>
89	       DP_PIN_ASSIGNMENT_SHIFT(dig_port->tc_phy_fia_idx);
90}
91
92int intel_tc_port_fia_max_lane_count(struct intel_digital_port *dig_port)
93{
94	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
95	intel_wakeref_t wakeref;
96	u32 lane_mask;
97
98	if (dig_port->tc_mode != TC_PORT_DP_ALT)
99		return 4;
100
101	lane_mask = 0;
102	with_intel_display_power(i915, POWER_DOMAIN_DISPLAY_CORE, wakeref)
103		lane_mask = intel_tc_port_get_lane_mask(dig_port);
104
105	switch (lane_mask) {
106	default:
107		MISSING_CASE(lane_mask);
108		/* fall-through */
109	case 0x1:
110	case 0x2:
111	case 0x4:
112	case 0x8:
113		return 1;
114	case 0x3:
115	case 0xc:
116		return 2;
117	case 0xf:
118		return 4;
119	}
120}
121
122void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
123				      int required_lanes)
124{
125	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
126	bool lane_reversal = dig_port->saved_port_bits & DDI_BUF_PORT_REVERSAL;
127	struct intel_uncore *uncore = &i915->uncore;
128	u32 val;
129
130	WARN_ON(lane_reversal && dig_port->tc_mode != TC_PORT_LEGACY);
131
132	val = intel_uncore_read(uncore,
133				PORT_TX_DFLEXDPMLE1(dig_port->tc_phy_fia));
134	val &= ~DFLEXDPMLE1_DPMLETC_MASK(dig_port->tc_phy_fia_idx);
135
136	switch (required_lanes) {
137	case 1:
138		val |= lane_reversal ?
139			DFLEXDPMLE1_DPMLETC_ML3(dig_port->tc_phy_fia_idx) :
140			DFLEXDPMLE1_DPMLETC_ML0(dig_port->tc_phy_fia_idx);
141		break;
142	case 2:
143		val |= lane_reversal ?
144			DFLEXDPMLE1_DPMLETC_ML3_2(dig_port->tc_phy_fia_idx) :
145			DFLEXDPMLE1_DPMLETC_ML1_0(dig_port->tc_phy_fia_idx);
146		break;
147	case 4:
148		val |= DFLEXDPMLE1_DPMLETC_ML3_0(dig_port->tc_phy_fia_idx);
149		break;
150	default:
151		MISSING_CASE(required_lanes);
152	}
153
154	intel_uncore_write(uncore,
155			   PORT_TX_DFLEXDPMLE1(dig_port->tc_phy_fia), val);
156}
157
158static void tc_port_fixup_legacy_flag(struct intel_digital_port *dig_port,
159				      u32 live_status_mask)
160{
161	u32 valid_hpd_mask;
162
163	if (dig_port->tc_legacy_port)
164		valid_hpd_mask = BIT(TC_PORT_LEGACY);
165	else
166		valid_hpd_mask = BIT(TC_PORT_DP_ALT) |
167				 BIT(TC_PORT_TBT_ALT);
168
169	if (!(live_status_mask & ~valid_hpd_mask))
170		return;
171
172	/* If live status mismatches the VBT flag, trust the live status. */
173	DRM_ERROR("Port %s: live status %08x mismatches the legacy port flag, fix flag\n",
174		  dig_port->tc_port_name, live_status_mask);
175
176	dig_port->tc_legacy_port = !dig_port->tc_legacy_port;
177}
178
179static u32 tc_port_live_status_mask(struct intel_digital_port *dig_port)
180{
181	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
182	enum tc_port tc_port = intel_port_to_tc(i915, dig_port->base.port);
183	struct intel_uncore *uncore = &i915->uncore;
184	u32 mask = 0;
185	u32 val;
186
187	val = intel_uncore_read(uncore,
188				PORT_TX_DFLEXDPSP(dig_port->tc_phy_fia));
189
190	if (val == 0xffffffff) {
191		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, nothing connected\n",
192			      dig_port->tc_port_name);
193		return mask;
194	}
195
196	if (val & TC_LIVE_STATE_TBT(dig_port->tc_phy_fia_idx))
197		mask |= BIT(TC_PORT_TBT_ALT);
198	if (val & TC_LIVE_STATE_TC(dig_port->tc_phy_fia_idx))
199		mask |= BIT(TC_PORT_DP_ALT);
200
201	if (intel_uncore_read(uncore, SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port))
202		mask |= BIT(TC_PORT_LEGACY);
203
204	/* The sink can be connected only in a single mode. */
205	if (!WARN_ON(hweight32(mask) > 1))
206		tc_port_fixup_legacy_flag(dig_port, mask);
207
208	return mask;
209}
210
211static bool icl_tc_phy_status_complete(struct intel_digital_port *dig_port)
212{
213	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
214	struct intel_uncore *uncore = &i915->uncore;
215	u32 val;
216
217	val = intel_uncore_read(uncore,
218				PORT_TX_DFLEXDPPMS(dig_port->tc_phy_fia));
219	if (val == 0xffffffff) {
220		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, assuming not complete\n",
221			      dig_port->tc_port_name);
222		return false;
223	}
224
225	return val & DP_PHY_MODE_STATUS_COMPLETED(dig_port->tc_phy_fia_idx);
226}
227
228static bool icl_tc_phy_set_safe_mode(struct intel_digital_port *dig_port,
229				     bool enable)
230{
231	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
232	struct intel_uncore *uncore = &i915->uncore;
233	u32 val;
234
235	val = intel_uncore_read(uncore,
236				PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia));
237	if (val == 0xffffffff) {
238		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, can't set safe-mode to %s\n",
239			      dig_port->tc_port_name,
240			      enableddisabled(enable));
241
242		return false;
243	}
244
245	val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx);
246	if (!enable)
247		val |= DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx);
248
249	intel_uncore_write(uncore,
250			   PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia), val);
251
252	if (enable && wait_for(!icl_tc_phy_status_complete(dig_port), 10))
253		DRM_DEBUG_KMS("Port %s: PHY complete clear timed out\n",
254			      dig_port->tc_port_name);
255
256	return true;
257}
258
259static bool icl_tc_phy_is_in_safe_mode(struct intel_digital_port *dig_port)
260{
261	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
262	struct intel_uncore *uncore = &i915->uncore;
263	u32 val;
264
265	val = intel_uncore_read(uncore,
266				PORT_TX_DFLEXDPCSSS(dig_port->tc_phy_fia));
267	if (val == 0xffffffff) {
268		DRM_DEBUG_KMS("Port %s: PHY in TCCOLD, assume safe mode\n",
269			      dig_port->tc_port_name);
270		return true;
271	}
272
273	return !(val & DP_PHY_MODE_STATUS_NOT_SAFE(dig_port->tc_phy_fia_idx));
274}
275
276/*
277 * This function implements the first part of the Connect Flow described by our
278 * specification, Gen11 TypeC Programming chapter. The rest of the flow (reading
279 * lanes, EDID, etc) is done as needed in the typical places.
280 *
281 * Unlike the other ports, type-C ports are not available to use as soon as we
282 * get a hotplug. The type-C PHYs can be shared between multiple controllers:
283 * display, USB, etc. As a result, handshaking through FIA is required around
284 * connect and disconnect to cleanly transfer ownership with the controller and
285 * set the type-C power state.
286 */
287static void icl_tc_phy_connect(struct intel_digital_port *dig_port,
288			       int required_lanes)
289{
290	int max_lanes;
291
292	if (!icl_tc_phy_status_complete(dig_port)) {
293		DRM_DEBUG_KMS("Port %s: PHY not ready\n",
294			      dig_port->tc_port_name);
295		goto out_set_tbt_alt_mode;
296	}
297
298	if (!icl_tc_phy_set_safe_mode(dig_port, false) &&
299	    !WARN_ON(dig_port->tc_legacy_port))
300		goto out_set_tbt_alt_mode;
301
302	max_lanes = intel_tc_port_fia_max_lane_count(dig_port);
303	if (dig_port->tc_legacy_port) {
304		WARN_ON(max_lanes != 4);
305		dig_port->tc_mode = TC_PORT_LEGACY;
306
307		return;
308	}
309
310	/*
311	 * Now we have to re-check the live state, in case the port recently
312	 * became disconnected. Not necessary for legacy mode.
313	 */
314	if (!(tc_port_live_status_mask(dig_port) & BIT(TC_PORT_DP_ALT))) {
315		DRM_DEBUG_KMS("Port %s: PHY sudden disconnect\n",
316			      dig_port->tc_port_name);
317		goto out_set_safe_mode;
318	}
319
320	if (max_lanes < required_lanes) {
321		DRM_DEBUG_KMS("Port %s: PHY max lanes %d < required lanes %d\n",
322			      dig_port->tc_port_name,
323			      max_lanes, required_lanes);
324		goto out_set_safe_mode;
325	}
326
327	dig_port->tc_mode = TC_PORT_DP_ALT;
328
329	return;
330
331out_set_safe_mode:
332	icl_tc_phy_set_safe_mode(dig_port, true);
333out_set_tbt_alt_mode:
334	dig_port->tc_mode = TC_PORT_TBT_ALT;
335}
336
337/*
338 * See the comment at the connect function. This implements the Disconnect
339 * Flow.
340 */
341static void icl_tc_phy_disconnect(struct intel_digital_port *dig_port)
342{
343	switch (dig_port->tc_mode) {
344	case TC_PORT_LEGACY:
345		/* Nothing to do, we never disconnect from legacy mode */
346		break;
347	case TC_PORT_DP_ALT:
348		icl_tc_phy_set_safe_mode(dig_port, true);
349		dig_port->tc_mode = TC_PORT_TBT_ALT;
350		break;
351	case TC_PORT_TBT_ALT:
352		/* Nothing to do, we stay in TBT-alt mode */
353		break;
354	default:
355		MISSING_CASE(dig_port->tc_mode);
356	}
357}
358
359static bool icl_tc_phy_is_connected(struct intel_digital_port *dig_port)
360{
361	if (!icl_tc_phy_status_complete(dig_port)) {
362		DRM_DEBUG_KMS("Port %s: PHY status not complete\n",
363			      dig_port->tc_port_name);
364		return dig_port->tc_mode == TC_PORT_TBT_ALT;
365	}
366
367	if (icl_tc_phy_is_in_safe_mode(dig_port)) {
368		DRM_DEBUG_KMS("Port %s: PHY still in safe mode\n",
369			      dig_port->tc_port_name);
370
371		return false;
372	}
373
374	return dig_port->tc_mode == TC_PORT_DP_ALT ||
375	       dig_port->tc_mode == TC_PORT_LEGACY;
376}
377
378static enum tc_port_mode
379intel_tc_port_get_current_mode(struct intel_digital_port *dig_port)
380{
381	u32 live_status_mask = tc_port_live_status_mask(dig_port);
382	bool in_safe_mode = icl_tc_phy_is_in_safe_mode(dig_port);
383	enum tc_port_mode mode;
384
385	if (in_safe_mode || WARN_ON(!icl_tc_phy_status_complete(dig_port)))
386		return TC_PORT_TBT_ALT;
387
388	mode = dig_port->tc_legacy_port ? TC_PORT_LEGACY : TC_PORT_DP_ALT;
389	if (live_status_mask) {
390		enum tc_port_mode live_mode = fls(live_status_mask) - 1;
391
392		if (!WARN_ON(live_mode == TC_PORT_TBT_ALT))
393			mode = live_mode;
394	}
395
396	return mode;
397}
398
399static enum tc_port_mode
400intel_tc_port_get_target_mode(struct intel_digital_port *dig_port)
401{
402	u32 live_status_mask = tc_port_live_status_mask(dig_port);
403
404	if (live_status_mask)
405		return fls(live_status_mask) - 1;
406
407	return icl_tc_phy_status_complete(dig_port) &&
408	       dig_port->tc_legacy_port ? TC_PORT_LEGACY :
409					  TC_PORT_TBT_ALT;
410}
411
412static void intel_tc_port_reset_mode(struct intel_digital_port *dig_port,
413				     int required_lanes)
414{
415	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
416	enum tc_port_mode old_tc_mode = dig_port->tc_mode;
417
418	intel_display_power_flush_work(i915);
419	WARN_ON(intel_display_power_is_enabled(i915,
420					       intel_aux_power_domain(dig_port)));
421
422	icl_tc_phy_disconnect(dig_port);
423	icl_tc_phy_connect(dig_port, required_lanes);
424
425	DRM_DEBUG_KMS("Port %s: TC port mode reset (%s -> %s)\n",
426		      dig_port->tc_port_name,
427		      tc_port_mode_name(old_tc_mode),
428		      tc_port_mode_name(dig_port->tc_mode));
429}
430
431static void
432intel_tc_port_link_init_refcount(struct intel_digital_port *dig_port,
433				 int refcount)
434{
435	WARN_ON(dig_port->tc_link_refcount);
436	dig_port->tc_link_refcount = refcount;
437}
438
439void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
440{
441	struct intel_encoder *encoder = &dig_port->base;
442	int active_links = 0;
443
444	mutex_lock(&dig_port->tc_lock);
445
446	dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
447	if (dig_port->dp.is_mst)
448		active_links = intel_dp_mst_encoder_active_links(dig_port);
449	else if (encoder->base.crtc)
450		active_links = to_intel_crtc(encoder->base.crtc)->active;
451
452	if (active_links) {
453		if (!icl_tc_phy_is_connected(dig_port))
454			DRM_DEBUG_KMS("Port %s: PHY disconnected with %d active link(s)\n",
455				      dig_port->tc_port_name, active_links);
456		intel_tc_port_link_init_refcount(dig_port, active_links);
457
458		goto out;
459	}
460
461	if (dig_port->tc_legacy_port)
462		icl_tc_phy_connect(dig_port, 1);
463
464out:
465	DRM_DEBUG_KMS("Port %s: sanitize mode (%s)\n",
466		      dig_port->tc_port_name,
467		      tc_port_mode_name(dig_port->tc_mode));
468
469	mutex_unlock(&dig_port->tc_lock);
470}
471
472static bool intel_tc_port_needs_reset(struct intel_digital_port *dig_port)
473{
474	return intel_tc_port_get_target_mode(dig_port) != dig_port->tc_mode;
475}
476
477/*
478 * The type-C ports are different because even when they are connected, they may
479 * not be available/usable by the graphics driver: see the comment on
480 * icl_tc_phy_connect(). So in our driver instead of adding the additional
481 * concept of "usable" and make everything check for "connected and usable" we
482 * define a port as "connected" when it is not only connected, but also when it
483 * is usable by the rest of the driver. That maintains the old assumption that
484 * connected ports are usable, and avoids exposing to the users objects they
485 * can't really use.
486 */
487bool intel_tc_port_connected(struct intel_digital_port *dig_port)
488{
489	bool is_connected;
490
491	intel_tc_port_lock(dig_port);
492	is_connected = tc_port_live_status_mask(dig_port) &
493		       BIT(dig_port->tc_mode);
494	intel_tc_port_unlock(dig_port);
495
496	return is_connected;
497}
498
499static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
500				 int required_lanes)
501{
502	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
503	intel_wakeref_t wakeref;
504
505	wakeref = intel_display_power_get(i915, POWER_DOMAIN_DISPLAY_CORE);
506
507	mutex_lock(&dig_port->tc_lock);
508
509	if (!dig_port->tc_link_refcount &&
510	    intel_tc_port_needs_reset(dig_port))
511		intel_tc_port_reset_mode(dig_port, required_lanes);
512
513	WARN_ON(dig_port->tc_lock_wakeref);
514	dig_port->tc_lock_wakeref = wakeref;
515}
516
517void intel_tc_port_lock(struct intel_digital_port *dig_port)
518{
519	__intel_tc_port_lock(dig_port, 1);
520}
521
522void intel_tc_port_unlock(struct intel_digital_port *dig_port)
523{
524	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
525	intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);
526
527	mutex_unlock(&dig_port->tc_lock);
528
529	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
530				      wakeref);
531}
532
533bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
534{
535	return mutex_is_locked(&dig_port->tc_lock) ||
536	       dig_port->tc_link_refcount;
537}
538
539void intel_tc_port_get_link(struct intel_digital_port *dig_port,
540			    int required_lanes)
541{
542	__intel_tc_port_lock(dig_port, required_lanes);
543	dig_port->tc_link_refcount++;
544	intel_tc_port_unlock(dig_port);
545}
546
547void intel_tc_port_put_link(struct intel_digital_port *dig_port)
548{
549	mutex_lock(&dig_port->tc_lock);
550	dig_port->tc_link_refcount--;
551	mutex_unlock(&dig_port->tc_lock);
552}
553
554void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
555{
556	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
557	enum port port = dig_port->base.port;
558	enum tc_port tc_port = intel_port_to_tc(i915, port);
559
560	if (WARN_ON(tc_port == PORT_TC_NONE))
561		return;
562
563	snprintf(dig_port->tc_port_name, sizeof(dig_port->tc_port_name),
564		 "%c/TC#%d", port_name(port), tc_port + 1);
565
566	mutex_init(&dig_port->tc_lock);
567	dig_port->tc_legacy_port = is_legacy;
568	dig_port->tc_link_refcount = 0;
569	tc_port_load_fia_params(i915, dig_port);
570}
571