1 /*
2  * Copyright 2012-15 Advanced Micro Devices, Inc.
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 shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: AMD
23  *
24  */
25 
26 
27 #include "reg_helper.h"
28 
29 #include "core_types.h"
30 #include "link_encoder.h"
31 #include "dcn31_dio_link_encoder.h"
32 #include "stream_encoder.h"
33 #include "i2caux_interface.h"
34 #include "dc_bios_types.h"
35 
36 #include "gpio_service_interface.h"
37 
38 #include "link_enc_cfg.h"
39 #include "dc_dmub_srv.h"
40 #include "dal_asic_id.h"
41 
42 #define CTX \
43 	enc10->base.ctx
44 #define DC_LOGGER \
45 	enc10->base.ctx->logger
46 
47 #define REG(reg)\
48 	(enc10->link_regs->reg)
49 
50 #undef FN
51 #define FN(reg_name, field_name) \
52 	enc10->link_shift->field_name, enc10->link_mask->field_name
53 
54 #define IND_REG(index) \
55 	(enc10->link_regs->index)
56 
57 #define AUX_REG(reg)\
58 	(enc10->aux_regs->reg)
59 
60 #define AUX_REG_READ(reg_name) \
61 		dm_read_reg(CTX, AUX_REG(reg_name))
62 
63 #define AUX_REG_WRITE(reg_name, val) \
64 			dm_write_reg(CTX, AUX_REG(reg_name), val)
65 
66 #ifndef MIN
67 #define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
68 #endif
69 
dcn31_link_encoder_set_dio_phy_mux(struct link_encoder * enc,enum encoder_type_select sel,uint32_t hpo_inst)70 void dcn31_link_encoder_set_dio_phy_mux(
71 	struct link_encoder *enc,
72 	enum encoder_type_select sel,
73 	uint32_t hpo_inst)
74 {
75 	struct dcn10_link_encoder *enc10 = TO_DCN10_LINK_ENC(enc);
76 
77 	switch (enc->transmitter) {
78 	case TRANSMITTER_UNIPHY_A:
79 		if (sel == ENCODER_TYPE_HDMI_FRL)
80 			REG_UPDATE(DIO_LINKA_CNTL,
81 					HPO_HDMI_ENC_SEL, hpo_inst);
82 		else if (sel == ENCODER_TYPE_DP_128B132B)
83 			REG_UPDATE(DIO_LINKA_CNTL,
84 					HPO_DP_ENC_SEL, hpo_inst);
85 		REG_UPDATE(DIO_LINKA_CNTL,
86 				ENC_TYPE_SEL, sel);
87 		break;
88 	case TRANSMITTER_UNIPHY_B:
89 		if (sel == ENCODER_TYPE_HDMI_FRL)
90 			REG_UPDATE(DIO_LINKB_CNTL,
91 					HPO_HDMI_ENC_SEL, hpo_inst);
92 		else if (sel == ENCODER_TYPE_DP_128B132B)
93 			REG_UPDATE(DIO_LINKB_CNTL,
94 					HPO_DP_ENC_SEL, hpo_inst);
95 		REG_UPDATE(DIO_LINKB_CNTL,
96 				ENC_TYPE_SEL, sel);
97 		break;
98 	case TRANSMITTER_UNIPHY_C:
99 		if (sel == ENCODER_TYPE_HDMI_FRL)
100 			REG_UPDATE(DIO_LINKC_CNTL,
101 					HPO_HDMI_ENC_SEL, hpo_inst);
102 		else if (sel == ENCODER_TYPE_DP_128B132B)
103 			REG_UPDATE(DIO_LINKC_CNTL,
104 					HPO_DP_ENC_SEL, hpo_inst);
105 		REG_UPDATE(DIO_LINKC_CNTL,
106 				ENC_TYPE_SEL, sel);
107 		break;
108 	case TRANSMITTER_UNIPHY_D:
109 		if (sel == ENCODER_TYPE_HDMI_FRL)
110 			REG_UPDATE(DIO_LINKD_CNTL,
111 					HPO_HDMI_ENC_SEL, hpo_inst);
112 		else if (sel == ENCODER_TYPE_DP_128B132B)
113 			REG_UPDATE(DIO_LINKD_CNTL,
114 					HPO_DP_ENC_SEL, hpo_inst);
115 		REG_UPDATE(DIO_LINKD_CNTL,
116 				ENC_TYPE_SEL, sel);
117 		break;
118 	case TRANSMITTER_UNIPHY_E:
119 		if (sel == ENCODER_TYPE_HDMI_FRL)
120 			REG_UPDATE(DIO_LINKE_CNTL,
121 					HPO_HDMI_ENC_SEL, hpo_inst);
122 		else if (sel == ENCODER_TYPE_DP_128B132B)
123 			REG_UPDATE(DIO_LINKE_CNTL,
124 					HPO_DP_ENC_SEL, hpo_inst);
125 		REG_UPDATE(DIO_LINKE_CNTL,
126 				ENC_TYPE_SEL, sel);
127 		break;
128 	case TRANSMITTER_UNIPHY_F:
129 		if (sel == ENCODER_TYPE_HDMI_FRL)
130 			REG_UPDATE(DIO_LINKF_CNTL,
131 					HPO_HDMI_ENC_SEL, hpo_inst);
132 		else if (sel == ENCODER_TYPE_DP_128B132B)
133 			REG_UPDATE(DIO_LINKF_CNTL,
134 					HPO_DP_ENC_SEL, hpo_inst);
135 		REG_UPDATE(DIO_LINKF_CNTL,
136 				ENC_TYPE_SEL, sel);
137 		break;
138 	default:
139 		/* Do nothing */
140 		break;
141 	}
142 }
143 
enc31_hw_init(struct link_encoder * enc)144 void enc31_hw_init(struct link_encoder *enc)
145 {
146 	struct dcn10_link_encoder *enc10 = TO_DCN10_LINK_ENC(enc);
147 
148 /*
149 	00 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__1to2 : 1/2
150 	01 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__3to4 : 3/4
151 	02 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__7to8 : 7/8
152 	03 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__15to16 : 15/16
153 	04 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__31to32 : 31/32
154 	05 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__63to64 : 63/64
155 	06 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__127to128 : 127/128
156 	07 - DP_AUX_DPHY_RX_DETECTION_THRESHOLD__255to256 : 255/256
157 */
158 
159 /*
160 	AUX_REG_UPDATE_5(AUX_DPHY_RX_CONTROL0,
161 	AUX_RX_START_WINDOW = 1 [6:4]
162 	AUX_RX_RECEIVE_WINDOW = 1 default is 2 [10:8]
163 	AUX_RX_HALF_SYM_DETECT_LEN  = 1 [13:12] default is 1
164 	AUX_RX_TRANSITION_FILTER_EN = 1 [16] default is 1
165 	AUX_RX_ALLOW_BELOW_THRESHOLD_PHASE_DETECT [17] is 0  default is 0
166 	AUX_RX_ALLOW_BELOW_THRESHOLD_START [18] is 1  default is 1
167 	AUX_RX_ALLOW_BELOW_THRESHOLD_STOP [19] is 1  default is 1
168 	AUX_RX_PHASE_DETECT_LEN,  [21,20] = 0x3 default is 3
169 	AUX_RX_DETECTION_THRESHOLD [30:28] = 1
170 */
171 	AUX_REG_WRITE(AUX_DPHY_RX_CONTROL0, 0x103d1110);
172 
173 	AUX_REG_WRITE(AUX_DPHY_TX_CONTROL, 0x21c7a);
174 
175 	//AUX_DPHY_TX_REF_CONTROL'AUX_TX_REF_DIV HW default is 0x32;
176 	// Set AUX_TX_REF_DIV Divider to generate 2 MHz reference from refclk
177 	// 27MHz -> 0xd
178 	// 100MHz -> 0x32
179 	// 48MHz -> 0x18
180 
181 #ifdef CLEANUP_FIXME
182 	/*from display_init*/
183 	REG_WRITE(RDPCSTX_DEBUG_CONFIG, 0);
184 #endif
185 
186 	// Set TMDS_CTL0 to 1.  This is a legacy setting.
187 	REG_UPDATE(TMDS_CTL_BITS, TMDS_CTL0, 1);
188 
189 	/*HW default is 5*/
190 	REG_UPDATE(RDPCSTX_CNTL,
191 			RDPCS_TX_FIFO_RD_START_DELAY, 4);
192 
193 	dcn10_aux_initialize(enc10);
194 }
195 
196 static const struct link_encoder_funcs dcn31_link_enc_funcs = {
197 	.read_state = link_enc2_read_state,
198 	.validate_output_with_stream =
199 			dcn30_link_encoder_validate_output_with_stream,
200 	.hw_init = enc31_hw_init,
201 	.setup = dcn10_link_encoder_setup,
202 	.enable_tmds_output = dcn10_link_encoder_enable_tmds_output,
203 	.enable_dp_output = dcn31_link_encoder_enable_dp_output,
204 	.enable_dp_mst_output = dcn31_link_encoder_enable_dp_mst_output,
205 	.disable_output = dcn31_link_encoder_disable_output,
206 	.dp_set_lane_settings = dcn10_link_encoder_dp_set_lane_settings,
207 	.dp_set_phy_pattern = dcn10_link_encoder_dp_set_phy_pattern,
208 	.update_mst_stream_allocation_table =
209 		dcn10_link_encoder_update_mst_stream_allocation_table,
210 	.psr_program_dp_dphy_fast_training =
211 			dcn10_psr_program_dp_dphy_fast_training,
212 	.psr_program_secondary_packet = dcn10_psr_program_secondary_packet,
213 	.connect_dig_be_to_fe = dcn10_link_encoder_connect_dig_be_to_fe,
214 	.enable_hpd = dcn10_link_encoder_enable_hpd,
215 	.disable_hpd = dcn10_link_encoder_disable_hpd,
216 	.is_dig_enabled = dcn10_is_dig_enabled,
217 	.destroy = dcn10_link_encoder_destroy,
218 	.fec_set_enable = enc2_fec_set_enable,
219 	.fec_set_ready = enc2_fec_set_ready,
220 	.fec_is_active = enc2_fec_is_active,
221 	.get_dig_frontend = dcn10_get_dig_frontend,
222 	.get_dig_mode = dcn10_get_dig_mode,
223 	.is_in_alt_mode = dcn31_link_encoder_is_in_alt_mode,
224 	.get_max_link_cap = dcn31_link_encoder_get_max_link_cap,
225 	.set_dio_phy_mux = dcn31_link_encoder_set_dio_phy_mux,
226 };
227 
dcn31_link_encoder_construct(struct dcn20_link_encoder * enc20,const struct encoder_init_data * init_data,const struct encoder_feature_support * enc_features,const struct dcn10_link_enc_registers * link_regs,const struct dcn10_link_enc_aux_registers * aux_regs,const struct dcn10_link_enc_hpd_registers * hpd_regs,const struct dcn10_link_enc_shift * link_shift,const struct dcn10_link_enc_mask * link_mask)228 void dcn31_link_encoder_construct(
229 	struct dcn20_link_encoder *enc20,
230 	const struct encoder_init_data *init_data,
231 	const struct encoder_feature_support *enc_features,
232 	const struct dcn10_link_enc_registers *link_regs,
233 	const struct dcn10_link_enc_aux_registers *aux_regs,
234 	const struct dcn10_link_enc_hpd_registers *hpd_regs,
235 	const struct dcn10_link_enc_shift *link_shift,
236 	const struct dcn10_link_enc_mask *link_mask)
237 {
238 	struct bp_encoder_cap_info bp_cap_info = {0};
239 	const struct dc_vbios_funcs *bp_funcs = init_data->ctx->dc_bios->funcs;
240 	enum bp_result result = BP_RESULT_OK;
241 	struct dcn10_link_encoder *enc10 = &enc20->enc10;
242 
243 	enc10->base.funcs = &dcn31_link_enc_funcs;
244 	enc10->base.ctx = init_data->ctx;
245 	enc10->base.id = init_data->encoder;
246 
247 	enc10->base.hpd_source = init_data->hpd_source;
248 	enc10->base.connector = init_data->connector;
249 
250 	enc10->base.preferred_engine = ENGINE_ID_UNKNOWN;
251 
252 	enc10->base.features = *enc_features;
253 
254 	enc10->base.transmitter = init_data->transmitter;
255 
256 	/* set the flag to indicate whether driver poll the I2C data pin
257 	 * while doing the DP sink detect
258 	 */
259 
260 /*	if (dal_adapter_service_is_feature_supported(as,
261 		FEATURE_DP_SINK_DETECT_POLL_DATA_PIN))
262 		enc10->base.features.flags.bits.
263 			DP_SINK_DETECT_POLL_DATA_PIN = true;*/
264 
265 	enc10->base.output_signals =
266 		SIGNAL_TYPE_DVI_SINGLE_LINK |
267 		SIGNAL_TYPE_DVI_DUAL_LINK |
268 		SIGNAL_TYPE_LVDS |
269 		SIGNAL_TYPE_DISPLAY_PORT |
270 		SIGNAL_TYPE_DISPLAY_PORT_MST |
271 		SIGNAL_TYPE_EDP |
272 		SIGNAL_TYPE_HDMI_TYPE_A;
273 
274 	/* For DCE 8.0 and 8.1, by design, UNIPHY is hardwired to DIG_BE.
275 	 * SW always assign DIG_FE 1:1 mapped to DIG_FE for non-MST UNIPHY.
276 	 * SW assign DIG_FE to non-MST UNIPHY first and MST last. So prefer
277 	 * DIG is per UNIPHY and used by SST DP, eDP, HDMI, DVI and LVDS.
278 	 * Prefer DIG assignment is decided by board design.
279 	 * For DCE 8.0, there are only max 6 UNIPHYs, we assume board design
280 	 * and VBIOS will filter out 7 UNIPHY for DCE 8.0.
281 	 * By this, adding DIGG should not hurt DCE 8.0.
282 	 * This will let DCE 8.1 share DCE 8.0 as much as possible
283 	 */
284 
285 	enc10->link_regs = link_regs;
286 	enc10->aux_regs = aux_regs;
287 	enc10->hpd_regs = hpd_regs;
288 	enc10->link_shift = link_shift;
289 	enc10->link_mask = link_mask;
290 
291 	switch (enc10->base.transmitter) {
292 	case TRANSMITTER_UNIPHY_A:
293 		enc10->base.preferred_engine = ENGINE_ID_DIGA;
294 	break;
295 	case TRANSMITTER_UNIPHY_B:
296 		enc10->base.preferred_engine = ENGINE_ID_DIGB;
297 	break;
298 	case TRANSMITTER_UNIPHY_C:
299 		enc10->base.preferred_engine = ENGINE_ID_DIGC;
300 	break;
301 	case TRANSMITTER_UNIPHY_D:
302 		enc10->base.preferred_engine = ENGINE_ID_DIGD;
303 	break;
304 	case TRANSMITTER_UNIPHY_E:
305 		enc10->base.preferred_engine = ENGINE_ID_DIGE;
306 	break;
307 	case TRANSMITTER_UNIPHY_F:
308 		enc10->base.preferred_engine = ENGINE_ID_DIGF;
309 	break;
310 	default:
311 		ASSERT_CRITICAL(false);
312 		enc10->base.preferred_engine = ENGINE_ID_UNKNOWN;
313 	}
314 
315 	/* default to one to mirror Windows behavior */
316 	enc10->base.features.flags.bits.HDMI_6GB_EN = 1;
317 
318 	result = bp_funcs->get_encoder_cap_info(enc10->base.ctx->dc_bios,
319 						enc10->base.id, &bp_cap_info);
320 
321 	/* Override features with DCE-specific values */
322 	if (result == BP_RESULT_OK) {
323 		enc10->base.features.flags.bits.IS_HBR2_CAPABLE =
324 				bp_cap_info.DP_HBR2_EN;
325 		enc10->base.features.flags.bits.IS_HBR3_CAPABLE =
326 				bp_cap_info.DP_HBR3_EN;
327 		enc10->base.features.flags.bits.HDMI_6GB_EN = bp_cap_info.HDMI_6GB_EN;
328 		enc10->base.features.flags.bits.DP_IS_USB_C =
329 				bp_cap_info.DP_IS_USB_C;
330 	} else {
331 		DC_LOG_WARNING("%s: Failed to get encoder_cap_info from VBIOS with error code %d!\n",
332 				__func__,
333 				result);
334 	}
335 	if (enc10->base.ctx->dc->debug.hdmi20_disable) {
336 		enc10->base.features.flags.bits.HDMI_6GB_EN = 0;
337 	}
338 }
339 
dcn31_link_encoder_construct_minimal(struct dcn20_link_encoder * enc20,struct dc_context * ctx,const struct encoder_feature_support * enc_features,const struct dcn10_link_enc_registers * link_regs,enum engine_id eng_id)340 void dcn31_link_encoder_construct_minimal(
341 	struct dcn20_link_encoder *enc20,
342 	struct dc_context *ctx,
343 	const struct encoder_feature_support *enc_features,
344 	const struct dcn10_link_enc_registers *link_regs,
345 	enum engine_id eng_id)
346 {
347 	struct dcn10_link_encoder *enc10 = &enc20->enc10;
348 
349 	enc10->base.funcs = &dcn31_link_enc_funcs;
350 	enc10->base.ctx = ctx;
351 	enc10->base.id.type = OBJECT_TYPE_ENCODER;
352 	enc10->base.hpd_source = HPD_SOURCEID_UNKNOWN;
353 	enc10->base.connector.type = OBJECT_TYPE_CONNECTOR;
354 	enc10->base.preferred_engine = eng_id;
355 	enc10->base.features = *enc_features;
356 	enc10->base.transmitter = TRANSMITTER_UNKNOWN;
357 	enc10->link_regs = link_regs;
358 
359 	enc10->base.output_signals =
360 		SIGNAL_TYPE_DISPLAY_PORT |
361 		SIGNAL_TYPE_DISPLAY_PORT_MST |
362 		SIGNAL_TYPE_EDP;
363 }
364 
dcn31_link_encoder_enable_dp_output(struct link_encoder * enc,const struct dc_link_settings * link_settings,enum clock_source_id clock_source)365 void dcn31_link_encoder_enable_dp_output(
366 	struct link_encoder *enc,
367 	const struct dc_link_settings *link_settings,
368 	enum clock_source_id clock_source)
369 {
370 	/* Enable transmitter and encoder. */
371 	if (!link_enc_cfg_is_transmitter_mappable(enc->ctx->dc->current_state, enc)) {
372 
373 		dcn20_link_encoder_enable_dp_output(enc, link_settings, clock_source);
374 
375 	} else {
376 
377 		/** @todo Handle transmitter with programmable mapping to link encoder. */
378 	}
379 }
380 
dcn31_link_encoder_enable_dp_mst_output(struct link_encoder * enc,const struct dc_link_settings * link_settings,enum clock_source_id clock_source)381 void dcn31_link_encoder_enable_dp_mst_output(
382 	struct link_encoder *enc,
383 	const struct dc_link_settings *link_settings,
384 	enum clock_source_id clock_source)
385 {
386 	/* Enable transmitter and encoder. */
387 	if (!link_enc_cfg_is_transmitter_mappable(enc->ctx->dc->current_state, enc)) {
388 
389 		dcn10_link_encoder_enable_dp_mst_output(enc, link_settings, clock_source);
390 
391 	} else {
392 
393 		/** @todo Handle transmitter with programmable mapping to link encoder. */
394 	}
395 }
396 
dcn31_link_encoder_disable_output(struct link_encoder * enc,enum signal_type signal)397 void dcn31_link_encoder_disable_output(
398 	struct link_encoder *enc,
399 	enum signal_type signal)
400 {
401 	/* Disable transmitter and encoder. */
402 	if (!link_enc_cfg_is_transmitter_mappable(enc->ctx->dc->current_state, enc)) {
403 
404 		dcn10_link_encoder_disable_output(enc, signal);
405 
406 	} else {
407 
408 		/** @todo Handle transmitter with programmable mapping to link encoder. */
409 	}
410 }
411 
dcn31_link_encoder_is_in_alt_mode(struct link_encoder * enc)412 bool dcn31_link_encoder_is_in_alt_mode(struct link_encoder *enc)
413 {
414 	struct dcn10_link_encoder *enc10 = TO_DCN10_LINK_ENC(enc);
415 	uint32_t dp_alt_mode_disable;
416 	bool is_usb_c_alt_mode = false;
417 
418 	if (enc->features.flags.bits.DP_IS_USB_C) {
419 		if (enc->ctx->asic_id.hw_internal_rev != YELLOW_CARP_B0) {
420 			// [Note] no need to check hw_internal_rev once phy mux selection is ready
421 			REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DISABLE, &dp_alt_mode_disable);
422 		} else {
423 		/*
424 		 * B0 phys use a new set of registers to check whether alt mode is disabled.
425 		 * if value == 1 alt mode is disabled, otherwise it is enabled.
426 		 */
427 			if ((enc10->base.transmitter == TRANSMITTER_UNIPHY_A)
428 					|| (enc10->base.transmitter == TRANSMITTER_UNIPHY_B)
429 					|| (enc10->base.transmitter == TRANSMITTER_UNIPHY_E)) {
430 				REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DISABLE, &dp_alt_mode_disable);
431 			} else {
432 			// [Note] need to change TRANSMITTER_UNIPHY_C/D to F/G once phy mux selection is ready
433 				REG_GET(RDPCSPIPE_PHY_CNTL6, RDPCS_PHY_DPALT_DISABLE, &dp_alt_mode_disable);
434 			}
435 		}
436 
437 		is_usb_c_alt_mode = (dp_alt_mode_disable == 0);
438 	}
439 
440 	return is_usb_c_alt_mode;
441 }
442 
dcn31_link_encoder_get_max_link_cap(struct link_encoder * enc,struct dc_link_settings * link_settings)443 void dcn31_link_encoder_get_max_link_cap(struct link_encoder *enc,
444 										 struct dc_link_settings *link_settings)
445 {
446 	struct dcn10_link_encoder *enc10 = TO_DCN10_LINK_ENC(enc);
447 	uint32_t is_in_usb_c_dp4_mode = 0;
448 
449 	dcn10_link_encoder_get_max_link_cap(enc, link_settings);
450 
451 	/* in usb c dp2 mode, max lane count is 2 */
452 	if (enc->funcs->is_in_alt_mode && enc->funcs->is_in_alt_mode(enc)) {
453 		if (enc->ctx->asic_id.hw_internal_rev != YELLOW_CARP_B0) {
454 			// [Note] no need to check hw_internal_rev once phy mux selection is ready
455 			REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
456 		} else {
457 			if ((enc10->base.transmitter == TRANSMITTER_UNIPHY_A)
458 					|| (enc10->base.transmitter == TRANSMITTER_UNIPHY_B)
459 					|| (enc10->base.transmitter == TRANSMITTER_UNIPHY_E)) {
460 				REG_GET(RDPCSTX_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
461 			} else {
462 				REG_GET(RDPCSPIPE_PHY_CNTL6, RDPCS_PHY_DPALT_DP4, &is_in_usb_c_dp4_mode);
463 			}
464 		}
465 		if (!is_in_usb_c_dp4_mode)
466 			link_settings->lane_count = MIN(LANE_COUNT_TWO, link_settings->lane_count);
467 	}
468 }
469