1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020-2021 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_reg.h"
8 #include "i915_trace.h"
9 #include "intel_bios.h"
10 #include "intel_de.h"
11 #include "intel_display_types.h"
12 #include "intel_dp_aux.h"
13 #include "intel_pps.h"
14 #include "intel_tc.h"
15 
16 static u32 intel_dp_aux_pack(const u8 *src, int src_bytes)
17 {
18 	int i;
19 	u32 v = 0;
20 
21 	if (src_bytes > 4)
22 		src_bytes = 4;
23 	for (i = 0; i < src_bytes; i++)
24 		v |= ((u32)src[i]) << ((3 - i) * 8);
25 	return v;
26 }
27 
28 static void intel_dp_aux_unpack(u32 src, u8 *dst, int dst_bytes)
29 {
30 	int i;
31 
32 	if (dst_bytes > 4)
33 		dst_bytes = 4;
34 	for (i = 0; i < dst_bytes; i++)
35 		dst[i] = src >> ((3 - i) * 8);
36 }
37 
38 static u32
39 intel_dp_aux_wait_done(struct intel_dp *intel_dp)
40 {
41 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
42 	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
43 	const unsigned int timeout_ms = 10;
44 	u32 status;
45 	int ret;
46 
47 	ret = __intel_de_wait_for_register(i915, ch_ctl,
48 					   DP_AUX_CH_CTL_SEND_BUSY, 0,
49 					   2, timeout_ms, &status);
50 
51 	if (ret == -ETIMEDOUT)
52 		drm_err(&i915->drm,
53 			"%s: did not complete or timeout within %ums (status 0x%08x)\n",
54 			intel_dp->aux.name, timeout_ms, status);
55 
56 	return status;
57 }
58 
59 static u32 g4x_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
60 {
61 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
62 
63 	if (index)
64 		return 0;
65 
66 	/*
67 	 * The clock divider is based off the hrawclk, and would like to run at
68 	 * 2MHz.  So, take the hrawclk value and divide by 2000 and use that
69 	 */
70 	return DIV_ROUND_CLOSEST(RUNTIME_INFO(dev_priv)->rawclk_freq, 2000);
71 }
72 
73 static u32 ilk_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
74 {
75 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
76 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
77 	u32 freq;
78 
79 	if (index)
80 		return 0;
81 
82 	/*
83 	 * The clock divider is based off the cdclk or PCH rawclk, and would
84 	 * like to run at 2MHz.  So, take the cdclk or PCH rawclk value and
85 	 * divide by 2000 and use that
86 	 */
87 	if (dig_port->aux_ch == AUX_CH_A)
88 		freq = dev_priv->display.cdclk.hw.cdclk;
89 	else
90 		freq = RUNTIME_INFO(dev_priv)->rawclk_freq;
91 	return DIV_ROUND_CLOSEST(freq, 2000);
92 }
93 
94 static u32 hsw_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
95 {
96 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
97 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
98 
99 	if (dig_port->aux_ch != AUX_CH_A && HAS_PCH_LPT_H(dev_priv)) {
100 		/* Workaround for non-ULT HSW */
101 		switch (index) {
102 		case 0: return 63;
103 		case 1: return 72;
104 		default: return 0;
105 		}
106 	}
107 
108 	return ilk_get_aux_clock_divider(intel_dp, index);
109 }
110 
111 static u32 skl_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
112 {
113 	/*
114 	 * SKL doesn't need us to program the AUX clock divider (Hardware will
115 	 * derive the clock from CDCLK automatically). We still implement the
116 	 * get_aux_clock_divider vfunc to plug-in into the existing code.
117 	 */
118 	return index ? 0 : 1;
119 }
120 
121 static u32 g4x_get_aux_send_ctl(struct intel_dp *intel_dp,
122 				int send_bytes,
123 				u32 aux_clock_divider)
124 {
125 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
126 	struct drm_i915_private *dev_priv =
127 			to_i915(dig_port->base.base.dev);
128 	u32 timeout;
129 
130 	/* Max timeout value on G4x-BDW: 1.6ms */
131 	if (IS_BROADWELL(dev_priv))
132 		timeout = DP_AUX_CH_CTL_TIME_OUT_600us;
133 	else
134 		timeout = DP_AUX_CH_CTL_TIME_OUT_400us;
135 
136 	return DP_AUX_CH_CTL_SEND_BUSY |
137 	       DP_AUX_CH_CTL_DONE |
138 	       DP_AUX_CH_CTL_INTERRUPT |
139 	       DP_AUX_CH_CTL_TIME_OUT_ERROR |
140 	       timeout |
141 	       DP_AUX_CH_CTL_RECEIVE_ERROR |
142 	       (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
143 	       (3 << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
144 	       (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT);
145 }
146 
147 static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
148 				int send_bytes,
149 				u32 unused)
150 {
151 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
152 	struct drm_i915_private *i915 =	to_i915(dig_port->base.base.dev);
153 	u32 ret;
154 
155 	/*
156 	 * Max timeout values:
157 	 * SKL-GLK: 1.6ms
158 	 * ICL+: 4ms
159 	 */
160 	ret = DP_AUX_CH_CTL_SEND_BUSY |
161 	      DP_AUX_CH_CTL_DONE |
162 	      DP_AUX_CH_CTL_INTERRUPT |
163 	      DP_AUX_CH_CTL_TIME_OUT_ERROR |
164 	      DP_AUX_CH_CTL_TIME_OUT_MAX |
165 	      DP_AUX_CH_CTL_RECEIVE_ERROR |
166 	      (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
167 	      DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(32) |
168 	      DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
169 
170 	if (intel_tc_port_in_tbt_alt_mode(dig_port))
171 		ret |= DP_AUX_CH_CTL_TBT_IO;
172 
173 	/*
174 	 * Power request bit is already set during aux power well enable.
175 	 * Preserve the bit across aux transactions.
176 	 */
177 	if (DISPLAY_VER(i915) >= 14)
178 		ret |= XELPDP_DP_AUX_CH_CTL_POWER_REQUEST;
179 
180 	return ret;
181 }
182 
183 static int
184 intel_dp_aux_xfer(struct intel_dp *intel_dp,
185 		  const u8 *send, int send_bytes,
186 		  u8 *recv, int recv_size,
187 		  u32 aux_send_ctl_flags)
188 {
189 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
190 	struct drm_i915_private *i915 =
191 			to_i915(dig_port->base.base.dev);
192 	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
193 	bool is_tc_port = intel_phy_is_tc(i915, phy);
194 	i915_reg_t ch_ctl, ch_data[5];
195 	u32 aux_clock_divider;
196 	enum intel_display_power_domain aux_domain;
197 	intel_wakeref_t aux_wakeref;
198 	intel_wakeref_t pps_wakeref;
199 	int i, ret, recv_bytes;
200 	int try, clock = 0;
201 	u32 status;
202 	bool vdd;
203 
204 	ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
205 	for (i = 0; i < ARRAY_SIZE(ch_data); i++)
206 		ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);
207 
208 	if (is_tc_port) {
209 		intel_tc_port_lock(dig_port);
210 		/*
211 		 * Abort transfers on a disconnected port as required by
212 		 * DP 1.4a link CTS 4.2.1.5, also avoiding the long AUX
213 		 * timeouts that would otherwise happen.
214 		 * TODO: abort the transfer on non-TC ports as well.
215 		 */
216 		if (!intel_tc_port_connected_locked(&dig_port->base)) {
217 			ret = -ENXIO;
218 			goto out_unlock;
219 		}
220 	}
221 
222 	aux_domain = intel_aux_power_domain(dig_port);
223 
224 	aux_wakeref = intel_display_power_get(i915, aux_domain);
225 	pps_wakeref = intel_pps_lock(intel_dp);
226 
227 	/*
228 	 * We will be called with VDD already enabled for dpcd/edid/oui reads.
229 	 * In such cases we want to leave VDD enabled and it's up to upper layers
230 	 * to turn it off. But for eg. i2c-dev access we need to turn it on/off
231 	 * ourselves.
232 	 */
233 	vdd = intel_pps_vdd_on_unlocked(intel_dp);
234 
235 	/*
236 	 * dp aux is extremely sensitive to irq latency, hence request the
237 	 * lowest possible wakeup latency and so prevent the cpu from going into
238 	 * deep sleep states.
239 	 */
240 	cpu_latency_qos_update_request(&intel_dp->pm_qos, 0);
241 
242 	intel_pps_check_power_unlocked(intel_dp);
243 
244 	/* Try to wait for any previous AUX channel activity */
245 	for (try = 0; try < 3; try++) {
246 		status = intel_de_read_notrace(i915, ch_ctl);
247 		if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
248 			break;
249 		msleep(1);
250 	}
251 	/* just trace the final value */
252 	trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);
253 
254 	if (try == 3) {
255 		const u32 status = intel_de_read(i915, ch_ctl);
256 
257 		if (status != intel_dp->aux_busy_last_status) {
258 			drm_WARN(&i915->drm, 1,
259 				 "%s: not started (status 0x%08x)\n",
260 				 intel_dp->aux.name, status);
261 			intel_dp->aux_busy_last_status = status;
262 		}
263 
264 		ret = -EBUSY;
265 		goto out;
266 	}
267 
268 	/* Only 5 data registers! */
269 	if (drm_WARN_ON(&i915->drm, send_bytes > 20 || recv_size > 20)) {
270 		ret = -E2BIG;
271 		goto out;
272 	}
273 
274 	while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
275 		u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
276 							  send_bytes,
277 							  aux_clock_divider);
278 
279 		send_ctl |= aux_send_ctl_flags;
280 
281 		/* Must try at least 3 times according to DP spec */
282 		for (try = 0; try < 5; try++) {
283 			/* Load the send data into the aux channel data registers */
284 			for (i = 0; i < send_bytes; i += 4)
285 				intel_de_write(i915, ch_data[i >> 2],
286 					       intel_dp_aux_pack(send + i,
287 								 send_bytes - i));
288 
289 			/* Send the command and wait for it to complete */
290 			intel_de_write(i915, ch_ctl, send_ctl);
291 
292 			status = intel_dp_aux_wait_done(intel_dp);
293 
294 			/* Clear done status and any errors */
295 			intel_de_write(i915, ch_ctl,
296 				       status | DP_AUX_CH_CTL_DONE |
297 				       DP_AUX_CH_CTL_TIME_OUT_ERROR |
298 				       DP_AUX_CH_CTL_RECEIVE_ERROR);
299 
300 			/*
301 			 * DP CTS 1.2 Core Rev 1.1, 4.2.1.1 & 4.2.1.2
302 			 *   400us delay required for errors and timeouts
303 			 *   Timeout errors from the HW already meet this
304 			 *   requirement so skip to next iteration
305 			 */
306 			if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR)
307 				continue;
308 
309 			if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
310 				usleep_range(400, 500);
311 				continue;
312 			}
313 			if (status & DP_AUX_CH_CTL_DONE)
314 				goto done;
315 		}
316 	}
317 
318 	if ((status & DP_AUX_CH_CTL_DONE) == 0) {
319 		drm_err(&i915->drm, "%s: not done (status 0x%08x)\n",
320 			intel_dp->aux.name, status);
321 		ret = -EBUSY;
322 		goto out;
323 	}
324 
325 done:
326 	/*
327 	 * Check for timeout or receive error. Timeouts occur when the sink is
328 	 * not connected.
329 	 */
330 	if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
331 		drm_err(&i915->drm, "%s: receive error (status 0x%08x)\n",
332 			intel_dp->aux.name, status);
333 		ret = -EIO;
334 		goto out;
335 	}
336 
337 	/*
338 	 * Timeouts occur when the device isn't connected, so they're "normal"
339 	 * -- don't fill the kernel log with these
340 	 */
341 	if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
342 		drm_dbg_kms(&i915->drm, "%s: timeout (status 0x%08x)\n",
343 			    intel_dp->aux.name, status);
344 		ret = -ETIMEDOUT;
345 		goto out;
346 	}
347 
348 	/* Unload any bytes sent back from the other side */
349 	recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
350 		      DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
351 
352 	/*
353 	 * By BSpec: "Message sizes of 0 or >20 are not allowed."
354 	 * We have no idea of what happened so we return -EBUSY so
355 	 * drm layer takes care for the necessary retries.
356 	 */
357 	if (recv_bytes == 0 || recv_bytes > 20) {
358 		drm_dbg_kms(&i915->drm,
359 			    "%s: Forbidden recv_bytes = %d on aux transaction\n",
360 			    intel_dp->aux.name, recv_bytes);
361 		ret = -EBUSY;
362 		goto out;
363 	}
364 
365 	if (recv_bytes > recv_size)
366 		recv_bytes = recv_size;
367 
368 	for (i = 0; i < recv_bytes; i += 4)
369 		intel_dp_aux_unpack(intel_de_read(i915, ch_data[i >> 2]),
370 				    recv + i, recv_bytes - i);
371 
372 	ret = recv_bytes;
373 out:
374 	cpu_latency_qos_update_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
375 
376 	if (vdd)
377 		intel_pps_vdd_off_unlocked(intel_dp, false);
378 
379 	intel_pps_unlock(intel_dp, pps_wakeref);
380 	intel_display_power_put_async(i915, aux_domain, aux_wakeref);
381 out_unlock:
382 	if (is_tc_port)
383 		intel_tc_port_unlock(dig_port);
384 
385 	return ret;
386 }
387 
388 #define BARE_ADDRESS_SIZE	3
389 #define HEADER_SIZE		(BARE_ADDRESS_SIZE + 1)
390 
391 static void
392 intel_dp_aux_header(u8 txbuf[HEADER_SIZE],
393 		    const struct drm_dp_aux_msg *msg)
394 {
395 	txbuf[0] = (msg->request << 4) | ((msg->address >> 16) & 0xf);
396 	txbuf[1] = (msg->address >> 8) & 0xff;
397 	txbuf[2] = msg->address & 0xff;
398 	txbuf[3] = msg->size - 1;
399 }
400 
401 static u32 intel_dp_aux_xfer_flags(const struct drm_dp_aux_msg *msg)
402 {
403 	/*
404 	 * If we're trying to send the HDCP Aksv, we need to set a the Aksv
405 	 * select bit to inform the hardware to send the Aksv after our header
406 	 * since we can't access that data from software.
407 	 */
408 	if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_WRITE &&
409 	    msg->address == DP_AUX_HDCP_AKSV)
410 		return DP_AUX_CH_CTL_AUX_AKSV_SELECT;
411 
412 	return 0;
413 }
414 
415 static ssize_t
416 intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
417 {
418 	struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux);
419 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
420 	u8 txbuf[20], rxbuf[20];
421 	size_t txsize, rxsize;
422 	u32 flags = intel_dp_aux_xfer_flags(msg);
423 	int ret;
424 
425 	intel_dp_aux_header(txbuf, msg);
426 
427 	switch (msg->request & ~DP_AUX_I2C_MOT) {
428 	case DP_AUX_NATIVE_WRITE:
429 	case DP_AUX_I2C_WRITE:
430 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
431 		txsize = msg->size ? HEADER_SIZE + msg->size : BARE_ADDRESS_SIZE;
432 		rxsize = 2; /* 0 or 1 data bytes */
433 
434 		if (drm_WARN_ON(&i915->drm, txsize > 20))
435 			return -E2BIG;
436 
437 		drm_WARN_ON(&i915->drm, !msg->buffer != !msg->size);
438 
439 		if (msg->buffer)
440 			memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);
441 
442 		ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
443 					rxbuf, rxsize, flags);
444 		if (ret > 0) {
445 			msg->reply = rxbuf[0] >> 4;
446 
447 			if (ret > 1) {
448 				/* Number of bytes written in a short write. */
449 				ret = clamp_t(int, rxbuf[1], 0, msg->size);
450 			} else {
451 				/* Return payload size. */
452 				ret = msg->size;
453 			}
454 		}
455 		break;
456 
457 	case DP_AUX_NATIVE_READ:
458 	case DP_AUX_I2C_READ:
459 		txsize = msg->size ? HEADER_SIZE : BARE_ADDRESS_SIZE;
460 		rxsize = msg->size + 1;
461 
462 		if (drm_WARN_ON(&i915->drm, rxsize > 20))
463 			return -E2BIG;
464 
465 		ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
466 					rxbuf, rxsize, flags);
467 		if (ret > 0) {
468 			msg->reply = rxbuf[0] >> 4;
469 			/*
470 			 * Assume happy day, and copy the data. The caller is
471 			 * expected to check msg->reply before touching it.
472 			 *
473 			 * Return payload size.
474 			 */
475 			ret--;
476 			memcpy(msg->buffer, rxbuf + 1, ret);
477 		}
478 		break;
479 
480 	default:
481 		ret = -EINVAL;
482 		break;
483 	}
484 
485 	return ret;
486 }
487 
488 static i915_reg_t g4x_aux_ctl_reg(struct intel_dp *intel_dp)
489 {
490 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
491 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
492 	enum aux_ch aux_ch = dig_port->aux_ch;
493 
494 	switch (aux_ch) {
495 	case AUX_CH_B:
496 	case AUX_CH_C:
497 	case AUX_CH_D:
498 		return DP_AUX_CH_CTL(aux_ch);
499 	default:
500 		MISSING_CASE(aux_ch);
501 		return DP_AUX_CH_CTL(AUX_CH_B);
502 	}
503 }
504 
505 static i915_reg_t g4x_aux_data_reg(struct intel_dp *intel_dp, int index)
506 {
507 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
508 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
509 	enum aux_ch aux_ch = dig_port->aux_ch;
510 
511 	switch (aux_ch) {
512 	case AUX_CH_B:
513 	case AUX_CH_C:
514 	case AUX_CH_D:
515 		return DP_AUX_CH_DATA(aux_ch, index);
516 	default:
517 		MISSING_CASE(aux_ch);
518 		return DP_AUX_CH_DATA(AUX_CH_B, index);
519 	}
520 }
521 
522 static i915_reg_t ilk_aux_ctl_reg(struct intel_dp *intel_dp)
523 {
524 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
525 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
526 	enum aux_ch aux_ch = dig_port->aux_ch;
527 
528 	switch (aux_ch) {
529 	case AUX_CH_A:
530 		return DP_AUX_CH_CTL(aux_ch);
531 	case AUX_CH_B:
532 	case AUX_CH_C:
533 	case AUX_CH_D:
534 		return PCH_DP_AUX_CH_CTL(aux_ch);
535 	default:
536 		MISSING_CASE(aux_ch);
537 		return DP_AUX_CH_CTL(AUX_CH_A);
538 	}
539 }
540 
541 static i915_reg_t ilk_aux_data_reg(struct intel_dp *intel_dp, int index)
542 {
543 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
544 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
545 	enum aux_ch aux_ch = dig_port->aux_ch;
546 
547 	switch (aux_ch) {
548 	case AUX_CH_A:
549 		return DP_AUX_CH_DATA(aux_ch, index);
550 	case AUX_CH_B:
551 	case AUX_CH_C:
552 	case AUX_CH_D:
553 		return PCH_DP_AUX_CH_DATA(aux_ch, index);
554 	default:
555 		MISSING_CASE(aux_ch);
556 		return DP_AUX_CH_DATA(AUX_CH_A, index);
557 	}
558 }
559 
560 static i915_reg_t skl_aux_ctl_reg(struct intel_dp *intel_dp)
561 {
562 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
563 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
564 	enum aux_ch aux_ch = dig_port->aux_ch;
565 
566 	switch (aux_ch) {
567 	case AUX_CH_A:
568 	case AUX_CH_B:
569 	case AUX_CH_C:
570 	case AUX_CH_D:
571 	case AUX_CH_E:
572 	case AUX_CH_F:
573 		return DP_AUX_CH_CTL(aux_ch);
574 	default:
575 		MISSING_CASE(aux_ch);
576 		return DP_AUX_CH_CTL(AUX_CH_A);
577 	}
578 }
579 
580 static i915_reg_t skl_aux_data_reg(struct intel_dp *intel_dp, int index)
581 {
582 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
583 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
584 	enum aux_ch aux_ch = dig_port->aux_ch;
585 
586 	switch (aux_ch) {
587 	case AUX_CH_A:
588 	case AUX_CH_B:
589 	case AUX_CH_C:
590 	case AUX_CH_D:
591 	case AUX_CH_E:
592 	case AUX_CH_F:
593 		return DP_AUX_CH_DATA(aux_ch, index);
594 	default:
595 		MISSING_CASE(aux_ch);
596 		return DP_AUX_CH_DATA(AUX_CH_A, index);
597 	}
598 }
599 
600 static i915_reg_t tgl_aux_ctl_reg(struct intel_dp *intel_dp)
601 {
602 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
603 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
604 	enum aux_ch aux_ch = dig_port->aux_ch;
605 
606 	switch (aux_ch) {
607 	case AUX_CH_A:
608 	case AUX_CH_B:
609 	case AUX_CH_C:
610 	case AUX_CH_USBC1:
611 	case AUX_CH_USBC2:
612 	case AUX_CH_USBC3:
613 	case AUX_CH_USBC4:
614 	case AUX_CH_USBC5:  /* aka AUX_CH_D_XELPD */
615 	case AUX_CH_USBC6:  /* aka AUX_CH_E_XELPD */
616 		return DP_AUX_CH_CTL(aux_ch);
617 	default:
618 		MISSING_CASE(aux_ch);
619 		return DP_AUX_CH_CTL(AUX_CH_A);
620 	}
621 }
622 
623 static i915_reg_t tgl_aux_data_reg(struct intel_dp *intel_dp, int index)
624 {
625 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
626 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
627 	enum aux_ch aux_ch = dig_port->aux_ch;
628 
629 	switch (aux_ch) {
630 	case AUX_CH_A:
631 	case AUX_CH_B:
632 	case AUX_CH_C:
633 	case AUX_CH_USBC1:
634 	case AUX_CH_USBC2:
635 	case AUX_CH_USBC3:
636 	case AUX_CH_USBC4:
637 	case AUX_CH_USBC5:  /* aka AUX_CH_D_XELPD */
638 	case AUX_CH_USBC6:  /* aka AUX_CH_E_XELPD */
639 		return DP_AUX_CH_DATA(aux_ch, index);
640 	default:
641 		MISSING_CASE(aux_ch);
642 		return DP_AUX_CH_DATA(AUX_CH_A, index);
643 	}
644 }
645 
646 static i915_reg_t xelpdp_aux_ctl_reg(struct intel_dp *intel_dp)
647 {
648 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
649 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
650 	enum aux_ch aux_ch = dig_port->aux_ch;
651 
652 	switch (aux_ch) {
653 	case AUX_CH_A:
654 	case AUX_CH_B:
655 	case AUX_CH_USBC1:
656 	case AUX_CH_USBC2:
657 	case AUX_CH_USBC3:
658 	case AUX_CH_USBC4:
659 		return XELPDP_DP_AUX_CH_CTL(aux_ch);
660 	default:
661 		MISSING_CASE(aux_ch);
662 		return XELPDP_DP_AUX_CH_CTL(AUX_CH_A);
663 	}
664 }
665 
666 static i915_reg_t xelpdp_aux_data_reg(struct intel_dp *intel_dp, int index)
667 {
668 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
669 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
670 	enum aux_ch aux_ch = dig_port->aux_ch;
671 
672 	switch (aux_ch) {
673 	case AUX_CH_A:
674 	case AUX_CH_B:
675 	case AUX_CH_USBC1:
676 	case AUX_CH_USBC2:
677 	case AUX_CH_USBC3:
678 	case AUX_CH_USBC4:
679 		return XELPDP_DP_AUX_CH_DATA(aux_ch, index);
680 	default:
681 		MISSING_CASE(aux_ch);
682 		return XELPDP_DP_AUX_CH_DATA(AUX_CH_A, index);
683 	}
684 }
685 
686 void intel_dp_aux_fini(struct intel_dp *intel_dp)
687 {
688 	if (cpu_latency_qos_request_active(&intel_dp->pm_qos))
689 		cpu_latency_qos_remove_request(&intel_dp->pm_qos);
690 
691 	kfree(intel_dp->aux.name);
692 }
693 
694 void intel_dp_aux_init(struct intel_dp *intel_dp)
695 {
696 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
697 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
698 	struct intel_encoder *encoder = &dig_port->base;
699 	enum aux_ch aux_ch = dig_port->aux_ch;
700 
701 	if (DISPLAY_VER(dev_priv) >= 14) {
702 		intel_dp->aux_ch_ctl_reg = xelpdp_aux_ctl_reg;
703 		intel_dp->aux_ch_data_reg = xelpdp_aux_data_reg;
704 	} else if (DISPLAY_VER(dev_priv) >= 12) {
705 		intel_dp->aux_ch_ctl_reg = tgl_aux_ctl_reg;
706 		intel_dp->aux_ch_data_reg = tgl_aux_data_reg;
707 	} else if (DISPLAY_VER(dev_priv) >= 9) {
708 		intel_dp->aux_ch_ctl_reg = skl_aux_ctl_reg;
709 		intel_dp->aux_ch_data_reg = skl_aux_data_reg;
710 	} else if (HAS_PCH_SPLIT(dev_priv)) {
711 		intel_dp->aux_ch_ctl_reg = ilk_aux_ctl_reg;
712 		intel_dp->aux_ch_data_reg = ilk_aux_data_reg;
713 	} else {
714 		intel_dp->aux_ch_ctl_reg = g4x_aux_ctl_reg;
715 		intel_dp->aux_ch_data_reg = g4x_aux_data_reg;
716 	}
717 
718 	if (DISPLAY_VER(dev_priv) >= 9)
719 		intel_dp->get_aux_clock_divider = skl_get_aux_clock_divider;
720 	else if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
721 		intel_dp->get_aux_clock_divider = hsw_get_aux_clock_divider;
722 	else if (HAS_PCH_SPLIT(dev_priv))
723 		intel_dp->get_aux_clock_divider = ilk_get_aux_clock_divider;
724 	else
725 		intel_dp->get_aux_clock_divider = g4x_get_aux_clock_divider;
726 
727 	if (DISPLAY_VER(dev_priv) >= 9)
728 		intel_dp->get_aux_send_ctl = skl_get_aux_send_ctl;
729 	else
730 		intel_dp->get_aux_send_ctl = g4x_get_aux_send_ctl;
731 
732 	intel_dp->aux.drm_dev = &dev_priv->drm;
733 	drm_dp_aux_init(&intel_dp->aux);
734 
735 	/* Failure to allocate our preferred name is not critical */
736 	if (DISPLAY_VER(dev_priv) >= 13 && aux_ch >= AUX_CH_D_XELPD)
737 		intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
738 					       aux_ch_name(aux_ch - AUX_CH_D_XELPD + AUX_CH_D),
739 					       encoder->base.name);
740 	else if (DISPLAY_VER(dev_priv) >= 12 && aux_ch >= AUX_CH_USBC1)
741 		intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX USBC%c/%s",
742 					       aux_ch - AUX_CH_USBC1 + '1',
743 					       encoder->base.name);
744 	else
745 		intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
746 					       aux_ch_name(aux_ch),
747 					       encoder->base.name);
748 
749 	intel_dp->aux.transfer = intel_dp_aux_transfer;
750 	cpu_latency_qos_add_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
751 }
752 
753 static enum aux_ch default_aux_ch(struct intel_encoder *encoder)
754 {
755 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
756 
757 	/* SKL has DDI E but no AUX E */
758 	if (DISPLAY_VER(i915) == 9 && encoder->port == PORT_E)
759 		return AUX_CH_A;
760 
761 	return (enum aux_ch)encoder->port;
762 }
763 
764 enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder)
765 {
766 	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
767 	enum aux_ch aux_ch;
768 
769 	aux_ch = intel_bios_dp_aux_ch(encoder->devdata);
770 	if (aux_ch != AUX_CH_NONE) {
771 		drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s] using AUX %c (VBT)\n",
772 			    encoder->base.base.id, encoder->base.name,
773 			    aux_ch_name(aux_ch));
774 		return aux_ch;
775 	}
776 
777 	aux_ch = default_aux_ch(encoder);
778 
779 	drm_dbg_kms(&i915->drm,
780 		    "[ENCODER:%d:%s] using AUX %c (platform default)\n",
781 		    encoder->base.base.id, encoder->base.name,
782 		    aux_ch_name(aux_ch));
783 
784 	return aux_ch;
785 }
786