1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2020-2021 Intel Corporation
4  */
5 
6 #include "i915_drv.h"
7 #include "i915_trace.h"
8 #include "intel_display_types.h"
9 #include "intel_dp_aux.h"
10 #include "intel_pps.h"
11 #include "intel_tc.h"
12 
13 u32 intel_dp_pack_aux(const u8 *src, int src_bytes)
14 {
15 	int i;
16 	u32 v = 0;
17 
18 	if (src_bytes > 4)
19 		src_bytes = 4;
20 	for (i = 0; i < src_bytes; i++)
21 		v |= ((u32)src[i]) << ((3 - i) * 8);
22 	return v;
23 }
24 
25 static void intel_dp_unpack_aux(u32 src, u8 *dst, int dst_bytes)
26 {
27 	int i;
28 
29 	if (dst_bytes > 4)
30 		dst_bytes = 4;
31 	for (i = 0; i < dst_bytes; i++)
32 		dst[i] = src >> ((3 - i) * 8);
33 }
34 
35 static u32
36 intel_dp_aux_wait_done(struct intel_dp *intel_dp)
37 {
38 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
39 	i915_reg_t ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
40 	const unsigned int timeout_ms = 10;
41 	u32 status;
42 	bool done;
43 
44 #define C (((status = intel_uncore_read_notrace(&i915->uncore, ch_ctl)) & DP_AUX_CH_CTL_SEND_BUSY) == 0)
45 	done = wait_event_timeout(i915->gmbus_wait_queue, C,
46 				  msecs_to_jiffies_timeout(timeout_ms));
47 
48 	/* just trace the final value */
49 	trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);
50 
51 	if (!done)
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 #undef C
56 
57 	return status;
58 }
59 
60 static u32 g4x_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
61 {
62 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
63 
64 	if (index)
65 		return 0;
66 
67 	/*
68 	 * The clock divider is based off the hrawclk, and would like to run at
69 	 * 2MHz.  So, take the hrawclk value and divide by 2000 and use that
70 	 */
71 	return DIV_ROUND_CLOSEST(RUNTIME_INFO(dev_priv)->rawclk_freq, 2000);
72 }
73 
74 static u32 ilk_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
75 {
76 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
77 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
78 	u32 freq;
79 
80 	if (index)
81 		return 0;
82 
83 	/*
84 	 * The clock divider is based off the cdclk or PCH rawclk, and would
85 	 * like to run at 2MHz.  So, take the cdclk or PCH rawclk value and
86 	 * divide by 2000 and use that
87 	 */
88 	if (dig_port->aux_ch == AUX_CH_A)
89 		freq = dev_priv->cdclk.hw.cdclk;
90 	else
91 		freq = RUNTIME_INFO(dev_priv)->rawclk_freq;
92 	return DIV_ROUND_CLOSEST(freq, 2000);
93 }
94 
95 static u32 hsw_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
96 {
97 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
98 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
99 
100 	if (dig_port->aux_ch != AUX_CH_A && HAS_PCH_LPT_H(dev_priv)) {
101 		/* Workaround for non-ULT HSW */
102 		switch (index) {
103 		case 0: return 63;
104 		case 1: return 72;
105 		default: return 0;
106 		}
107 	}
108 
109 	return ilk_get_aux_clock_divider(intel_dp, index);
110 }
111 
112 static u32 skl_get_aux_clock_divider(struct intel_dp *intel_dp, int index)
113 {
114 	/*
115 	 * SKL doesn't need us to program the AUX clock divider (Hardware will
116 	 * derive the clock from CDCLK automatically). We still implement the
117 	 * get_aux_clock_divider vfunc to plug-in into the existing code.
118 	 */
119 	return index ? 0 : 1;
120 }
121 
122 static u32 g4x_get_aux_send_ctl(struct intel_dp *intel_dp,
123 				int send_bytes,
124 				u32 aux_clock_divider)
125 {
126 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
127 	struct drm_i915_private *dev_priv =
128 			to_i915(dig_port->base.base.dev);
129 	u32 precharge, timeout;
130 
131 	if (IS_GEN(dev_priv, 6))
132 		precharge = 3;
133 	else
134 		precharge = 5;
135 
136 	/* Max timeout value on G4x-BDW: 1.6ms */
137 	if (IS_BROADWELL(dev_priv))
138 		timeout = DP_AUX_CH_CTL_TIME_OUT_600us;
139 	else
140 		timeout = DP_AUX_CH_CTL_TIME_OUT_400us;
141 
142 	return DP_AUX_CH_CTL_SEND_BUSY |
143 	       DP_AUX_CH_CTL_DONE |
144 	       DP_AUX_CH_CTL_INTERRUPT |
145 	       DP_AUX_CH_CTL_TIME_OUT_ERROR |
146 	       timeout |
147 	       DP_AUX_CH_CTL_RECEIVE_ERROR |
148 	       (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
149 	       (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
150 	       (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT);
151 }
152 
153 static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
154 				int send_bytes,
155 				u32 unused)
156 {
157 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
158 	struct drm_i915_private *i915 =
159 			to_i915(dig_port->base.base.dev);
160 	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
161 	u32 ret;
162 
163 	/*
164 	 * Max timeout values:
165 	 * SKL-GLK: 1.6ms
166 	 * CNL: 3.2ms
167 	 * ICL+: 4ms
168 	 */
169 	ret = DP_AUX_CH_CTL_SEND_BUSY |
170 	      DP_AUX_CH_CTL_DONE |
171 	      DP_AUX_CH_CTL_INTERRUPT |
172 	      DP_AUX_CH_CTL_TIME_OUT_ERROR |
173 	      DP_AUX_CH_CTL_TIME_OUT_MAX |
174 	      DP_AUX_CH_CTL_RECEIVE_ERROR |
175 	      (send_bytes << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
176 	      DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(32) |
177 	      DP_AUX_CH_CTL_SYNC_PULSE_SKL(32);
178 
179 	if (intel_phy_is_tc(i915, phy) &&
180 	    dig_port->tc_mode == TC_PORT_TBT_ALT)
181 		ret |= DP_AUX_CH_CTL_TBT_IO;
182 
183 	return ret;
184 }
185 
186 static int
187 intel_dp_aux_xfer(struct intel_dp *intel_dp,
188 		  const u8 *send, int send_bytes,
189 		  u8 *recv, int recv_size,
190 		  u32 aux_send_ctl_flags)
191 {
192 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
193 	struct drm_i915_private *i915 =
194 			to_i915(dig_port->base.base.dev);
195 	struct intel_uncore *uncore = &i915->uncore;
196 	enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
197 	bool is_tc_port = intel_phy_is_tc(i915, phy);
198 	i915_reg_t ch_ctl, ch_data[5];
199 	u32 aux_clock_divider;
200 	enum intel_display_power_domain aux_domain;
201 	intel_wakeref_t aux_wakeref;
202 	intel_wakeref_t pps_wakeref;
203 	int i, ret, recv_bytes;
204 	int try, clock = 0;
205 	u32 status;
206 	bool vdd;
207 
208 	ch_ctl = intel_dp->aux_ch_ctl_reg(intel_dp);
209 	for (i = 0; i < ARRAY_SIZE(ch_data); i++)
210 		ch_data[i] = intel_dp->aux_ch_data_reg(intel_dp, i);
211 
212 	if (is_tc_port)
213 		intel_tc_port_lock(dig_port);
214 
215 	aux_domain = intel_aux_power_domain(dig_port);
216 
217 	aux_wakeref = intel_display_power_get(i915, aux_domain);
218 	pps_wakeref = intel_pps_lock(intel_dp);
219 
220 	/*
221 	 * We will be called with VDD already enabled for dpcd/edid/oui reads.
222 	 * In such cases we want to leave VDD enabled and it's up to upper layers
223 	 * to turn it off. But for eg. i2c-dev access we need to turn it on/off
224 	 * ourselves.
225 	 */
226 	vdd = intel_pps_vdd_on_unlocked(intel_dp);
227 
228 	/*
229 	 * dp aux is extremely sensitive to irq latency, hence request the
230 	 * lowest possible wakeup latency and so prevent the cpu from going into
231 	 * deep sleep states.
232 	 */
233 	cpu_latency_qos_update_request(&intel_dp->pm_qos, 0);
234 
235 	intel_pps_check_power_unlocked(intel_dp);
236 
237 	/* Try to wait for any previous AUX channel activity */
238 	for (try = 0; try < 3; try++) {
239 		status = intel_uncore_read_notrace(uncore, ch_ctl);
240 		if ((status & DP_AUX_CH_CTL_SEND_BUSY) == 0)
241 			break;
242 		msleep(1);
243 	}
244 	/* just trace the final value */
245 	trace_i915_reg_rw(false, ch_ctl, status, sizeof(status), true);
246 
247 	if (try == 3) {
248 		const u32 status = intel_uncore_read(uncore, ch_ctl);
249 
250 		if (status != intel_dp->aux_busy_last_status) {
251 			drm_WARN(&i915->drm, 1,
252 				 "%s: not started (status 0x%08x)\n",
253 				 intel_dp->aux.name, status);
254 			intel_dp->aux_busy_last_status = status;
255 		}
256 
257 		ret = -EBUSY;
258 		goto out;
259 	}
260 
261 	/* Only 5 data registers! */
262 	if (drm_WARN_ON(&i915->drm, send_bytes > 20 || recv_size > 20)) {
263 		ret = -E2BIG;
264 		goto out;
265 	}
266 
267 	while ((aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, clock++))) {
268 		u32 send_ctl = intel_dp->get_aux_send_ctl(intel_dp,
269 							  send_bytes,
270 							  aux_clock_divider);
271 
272 		send_ctl |= aux_send_ctl_flags;
273 
274 		/* Must try at least 3 times according to DP spec */
275 		for (try = 0; try < 5; try++) {
276 			/* Load the send data into the aux channel data registers */
277 			for (i = 0; i < send_bytes; i += 4)
278 				intel_uncore_write(uncore,
279 						   ch_data[i >> 2],
280 						   intel_dp_pack_aux(send + i,
281 								     send_bytes - i));
282 
283 			/* Send the command and wait for it to complete */
284 			intel_uncore_write(uncore, ch_ctl, send_ctl);
285 
286 			status = intel_dp_aux_wait_done(intel_dp);
287 
288 			/* Clear done status and any errors */
289 			intel_uncore_write(uncore,
290 					   ch_ctl,
291 					   status |
292 					   DP_AUX_CH_CTL_DONE |
293 					   DP_AUX_CH_CTL_TIME_OUT_ERROR |
294 					   DP_AUX_CH_CTL_RECEIVE_ERROR);
295 
296 			/*
297 			 * DP CTS 1.2 Core Rev 1.1, 4.2.1.1 & 4.2.1.2
298 			 *   400us delay required for errors and timeouts
299 			 *   Timeout errors from the HW already meet this
300 			 *   requirement so skip to next iteration
301 			 */
302 			if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR)
303 				continue;
304 
305 			if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
306 				usleep_range(400, 500);
307 				continue;
308 			}
309 			if (status & DP_AUX_CH_CTL_DONE)
310 				goto done;
311 		}
312 	}
313 
314 	if ((status & DP_AUX_CH_CTL_DONE) == 0) {
315 		drm_err(&i915->drm, "%s: not done (status 0x%08x)\n",
316 			intel_dp->aux.name, status);
317 		ret = -EBUSY;
318 		goto out;
319 	}
320 
321 done:
322 	/*
323 	 * Check for timeout or receive error. Timeouts occur when the sink is
324 	 * not connected.
325 	 */
326 	if (status & DP_AUX_CH_CTL_RECEIVE_ERROR) {
327 		drm_err(&i915->drm, "%s: receive error (status 0x%08x)\n",
328 			intel_dp->aux.name, status);
329 		ret = -EIO;
330 		goto out;
331 	}
332 
333 	/*
334 	 * Timeouts occur when the device isn't connected, so they're "normal"
335 	 * -- don't fill the kernel log with these
336 	 */
337 	if (status & DP_AUX_CH_CTL_TIME_OUT_ERROR) {
338 		drm_dbg_kms(&i915->drm, "%s: timeout (status 0x%08x)\n",
339 			    intel_dp->aux.name, status);
340 		ret = -ETIMEDOUT;
341 		goto out;
342 	}
343 
344 	/* Unload any bytes sent back from the other side */
345 	recv_bytes = ((status & DP_AUX_CH_CTL_MESSAGE_SIZE_MASK) >>
346 		      DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT);
347 
348 	/*
349 	 * By BSpec: "Message sizes of 0 or >20 are not allowed."
350 	 * We have no idea of what happened so we return -EBUSY so
351 	 * drm layer takes care for the necessary retries.
352 	 */
353 	if (recv_bytes == 0 || recv_bytes > 20) {
354 		drm_dbg_kms(&i915->drm,
355 			    "%s: Forbidden recv_bytes = %d on aux transaction\n",
356 			    intel_dp->aux.name, recv_bytes);
357 		ret = -EBUSY;
358 		goto out;
359 	}
360 
361 	if (recv_bytes > recv_size)
362 		recv_bytes = recv_size;
363 
364 	for (i = 0; i < recv_bytes; i += 4)
365 		intel_dp_unpack_aux(intel_uncore_read(uncore, ch_data[i >> 2]),
366 				    recv + i, recv_bytes - i);
367 
368 	ret = recv_bytes;
369 out:
370 	cpu_latency_qos_update_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
371 
372 	if (vdd)
373 		intel_pps_vdd_off_unlocked(intel_dp, false);
374 
375 	intel_pps_unlock(intel_dp, pps_wakeref);
376 	intel_display_power_put_async(i915, aux_domain, aux_wakeref);
377 
378 	if (is_tc_port)
379 		intel_tc_port_unlock(dig_port);
380 
381 	return ret;
382 }
383 
384 #define BARE_ADDRESS_SIZE	3
385 #define HEADER_SIZE		(BARE_ADDRESS_SIZE + 1)
386 
387 static void
388 intel_dp_aux_header(u8 txbuf[HEADER_SIZE],
389 		    const struct drm_dp_aux_msg *msg)
390 {
391 	txbuf[0] = (msg->request << 4) | ((msg->address >> 16) & 0xf);
392 	txbuf[1] = (msg->address >> 8) & 0xff;
393 	txbuf[2] = msg->address & 0xff;
394 	txbuf[3] = msg->size - 1;
395 }
396 
397 static u32 intel_dp_aux_xfer_flags(const struct drm_dp_aux_msg *msg)
398 {
399 	/*
400 	 * If we're trying to send the HDCP Aksv, we need to set a the Aksv
401 	 * select bit to inform the hardware to send the Aksv after our header
402 	 * since we can't access that data from software.
403 	 */
404 	if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_NATIVE_WRITE &&
405 	    msg->address == DP_AUX_HDCP_AKSV)
406 		return DP_AUX_CH_CTL_AUX_AKSV_SELECT;
407 
408 	return 0;
409 }
410 
411 static ssize_t
412 intel_dp_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
413 {
414 	struct intel_dp *intel_dp = container_of(aux, struct intel_dp, aux);
415 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
416 	u8 txbuf[20], rxbuf[20];
417 	size_t txsize, rxsize;
418 	u32 flags = intel_dp_aux_xfer_flags(msg);
419 	int ret;
420 
421 	intel_dp_aux_header(txbuf, msg);
422 
423 	switch (msg->request & ~DP_AUX_I2C_MOT) {
424 	case DP_AUX_NATIVE_WRITE:
425 	case DP_AUX_I2C_WRITE:
426 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
427 		txsize = msg->size ? HEADER_SIZE + msg->size : BARE_ADDRESS_SIZE;
428 		rxsize = 2; /* 0 or 1 data bytes */
429 
430 		if (drm_WARN_ON(&i915->drm, txsize > 20))
431 			return -E2BIG;
432 
433 		drm_WARN_ON(&i915->drm, !msg->buffer != !msg->size);
434 
435 		if (msg->buffer)
436 			memcpy(txbuf + HEADER_SIZE, msg->buffer, msg->size);
437 
438 		ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
439 					rxbuf, rxsize, flags);
440 		if (ret > 0) {
441 			msg->reply = rxbuf[0] >> 4;
442 
443 			if (ret > 1) {
444 				/* Number of bytes written in a short write. */
445 				ret = clamp_t(int, rxbuf[1], 0, msg->size);
446 			} else {
447 				/* Return payload size. */
448 				ret = msg->size;
449 			}
450 		}
451 		break;
452 
453 	case DP_AUX_NATIVE_READ:
454 	case DP_AUX_I2C_READ:
455 		txsize = msg->size ? HEADER_SIZE : BARE_ADDRESS_SIZE;
456 		rxsize = msg->size + 1;
457 
458 		if (drm_WARN_ON(&i915->drm, rxsize > 20))
459 			return -E2BIG;
460 
461 		ret = intel_dp_aux_xfer(intel_dp, txbuf, txsize,
462 					rxbuf, rxsize, flags);
463 		if (ret > 0) {
464 			msg->reply = rxbuf[0] >> 4;
465 			/*
466 			 * Assume happy day, and copy the data. The caller is
467 			 * expected to check msg->reply before touching it.
468 			 *
469 			 * Return payload size.
470 			 */
471 			ret--;
472 			memcpy(msg->buffer, rxbuf + 1, ret);
473 		}
474 		break;
475 
476 	default:
477 		ret = -EINVAL;
478 		break;
479 	}
480 
481 	return ret;
482 }
483 
484 static i915_reg_t g4x_aux_ctl_reg(struct intel_dp *intel_dp)
485 {
486 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
487 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
488 	enum aux_ch aux_ch = dig_port->aux_ch;
489 
490 	switch (aux_ch) {
491 	case AUX_CH_B:
492 	case AUX_CH_C:
493 	case AUX_CH_D:
494 		return DP_AUX_CH_CTL(aux_ch);
495 	default:
496 		MISSING_CASE(aux_ch);
497 		return DP_AUX_CH_CTL(AUX_CH_B);
498 	}
499 }
500 
501 static i915_reg_t g4x_aux_data_reg(struct intel_dp *intel_dp, int index)
502 {
503 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
504 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
505 	enum aux_ch aux_ch = dig_port->aux_ch;
506 
507 	switch (aux_ch) {
508 	case AUX_CH_B:
509 	case AUX_CH_C:
510 	case AUX_CH_D:
511 		return DP_AUX_CH_DATA(aux_ch, index);
512 	default:
513 		MISSING_CASE(aux_ch);
514 		return DP_AUX_CH_DATA(AUX_CH_B, index);
515 	}
516 }
517 
518 static i915_reg_t ilk_aux_ctl_reg(struct intel_dp *intel_dp)
519 {
520 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
521 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
522 	enum aux_ch aux_ch = dig_port->aux_ch;
523 
524 	switch (aux_ch) {
525 	case AUX_CH_A:
526 		return DP_AUX_CH_CTL(aux_ch);
527 	case AUX_CH_B:
528 	case AUX_CH_C:
529 	case AUX_CH_D:
530 		return PCH_DP_AUX_CH_CTL(aux_ch);
531 	default:
532 		MISSING_CASE(aux_ch);
533 		return DP_AUX_CH_CTL(AUX_CH_A);
534 	}
535 }
536 
537 static i915_reg_t ilk_aux_data_reg(struct intel_dp *intel_dp, int index)
538 {
539 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
540 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
541 	enum aux_ch aux_ch = dig_port->aux_ch;
542 
543 	switch (aux_ch) {
544 	case AUX_CH_A:
545 		return DP_AUX_CH_DATA(aux_ch, index);
546 	case AUX_CH_B:
547 	case AUX_CH_C:
548 	case AUX_CH_D:
549 		return PCH_DP_AUX_CH_DATA(aux_ch, index);
550 	default:
551 		MISSING_CASE(aux_ch);
552 		return DP_AUX_CH_DATA(AUX_CH_A, index);
553 	}
554 }
555 
556 static i915_reg_t skl_aux_ctl_reg(struct intel_dp *intel_dp)
557 {
558 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
559 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
560 	enum aux_ch aux_ch = dig_port->aux_ch;
561 
562 	switch (aux_ch) {
563 	case AUX_CH_A:
564 	case AUX_CH_B:
565 	case AUX_CH_C:
566 	case AUX_CH_D:
567 	case AUX_CH_E:
568 	case AUX_CH_F:
569 		return DP_AUX_CH_CTL(aux_ch);
570 	default:
571 		MISSING_CASE(aux_ch);
572 		return DP_AUX_CH_CTL(AUX_CH_A);
573 	}
574 }
575 
576 static i915_reg_t skl_aux_data_reg(struct intel_dp *intel_dp, int index)
577 {
578 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
579 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
580 	enum aux_ch aux_ch = dig_port->aux_ch;
581 
582 	switch (aux_ch) {
583 	case AUX_CH_A:
584 	case AUX_CH_B:
585 	case AUX_CH_C:
586 	case AUX_CH_D:
587 	case AUX_CH_E:
588 	case AUX_CH_F:
589 		return DP_AUX_CH_DATA(aux_ch, index);
590 	default:
591 		MISSING_CASE(aux_ch);
592 		return DP_AUX_CH_DATA(AUX_CH_A, index);
593 	}
594 }
595 
596 static i915_reg_t tgl_aux_ctl_reg(struct intel_dp *intel_dp)
597 {
598 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
599 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
600 	enum aux_ch aux_ch = dig_port->aux_ch;
601 
602 	switch (aux_ch) {
603 	case AUX_CH_A:
604 	case AUX_CH_B:
605 	case AUX_CH_C:
606 	case AUX_CH_USBC1:
607 	case AUX_CH_USBC2:
608 	case AUX_CH_USBC3:
609 	case AUX_CH_USBC4:
610 	case AUX_CH_USBC5:
611 	case AUX_CH_USBC6:
612 		return DP_AUX_CH_CTL(aux_ch);
613 	default:
614 		MISSING_CASE(aux_ch);
615 		return DP_AUX_CH_CTL(AUX_CH_A);
616 	}
617 }
618 
619 static i915_reg_t tgl_aux_data_reg(struct intel_dp *intel_dp, int index)
620 {
621 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
622 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
623 	enum aux_ch aux_ch = dig_port->aux_ch;
624 
625 	switch (aux_ch) {
626 	case AUX_CH_A:
627 	case AUX_CH_B:
628 	case AUX_CH_C:
629 	case AUX_CH_USBC1:
630 	case AUX_CH_USBC2:
631 	case AUX_CH_USBC3:
632 	case AUX_CH_USBC4:
633 	case AUX_CH_USBC5:
634 	case AUX_CH_USBC6:
635 		return DP_AUX_CH_DATA(aux_ch, index);
636 	default:
637 		MISSING_CASE(aux_ch);
638 		return DP_AUX_CH_DATA(AUX_CH_A, index);
639 	}
640 }
641 
642 void intel_dp_aux_fini(struct intel_dp *intel_dp)
643 {
644 	if (cpu_latency_qos_request_active(&intel_dp->pm_qos))
645 		cpu_latency_qos_remove_request(&intel_dp->pm_qos);
646 
647 	kfree(intel_dp->aux.name);
648 }
649 
650 void intel_dp_aux_init(struct intel_dp *intel_dp)
651 {
652 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
653 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
654 	struct intel_encoder *encoder = &dig_port->base;
655 	enum aux_ch aux_ch = dig_port->aux_ch;
656 
657 	if (INTEL_GEN(dev_priv) >= 12) {
658 		intel_dp->aux_ch_ctl_reg = tgl_aux_ctl_reg;
659 		intel_dp->aux_ch_data_reg = tgl_aux_data_reg;
660 	} else if (INTEL_GEN(dev_priv) >= 9) {
661 		intel_dp->aux_ch_ctl_reg = skl_aux_ctl_reg;
662 		intel_dp->aux_ch_data_reg = skl_aux_data_reg;
663 	} else if (HAS_PCH_SPLIT(dev_priv)) {
664 		intel_dp->aux_ch_ctl_reg = ilk_aux_ctl_reg;
665 		intel_dp->aux_ch_data_reg = ilk_aux_data_reg;
666 	} else {
667 		intel_dp->aux_ch_ctl_reg = g4x_aux_ctl_reg;
668 		intel_dp->aux_ch_data_reg = g4x_aux_data_reg;
669 	}
670 
671 	if (INTEL_GEN(dev_priv) >= 9)
672 		intel_dp->get_aux_clock_divider = skl_get_aux_clock_divider;
673 	else if (IS_BROADWELL(dev_priv) || IS_HASWELL(dev_priv))
674 		intel_dp->get_aux_clock_divider = hsw_get_aux_clock_divider;
675 	else if (HAS_PCH_SPLIT(dev_priv))
676 		intel_dp->get_aux_clock_divider = ilk_get_aux_clock_divider;
677 	else
678 		intel_dp->get_aux_clock_divider = g4x_get_aux_clock_divider;
679 
680 	if (INTEL_GEN(dev_priv) >= 9)
681 		intel_dp->get_aux_send_ctl = skl_get_aux_send_ctl;
682 	else
683 		intel_dp->get_aux_send_ctl = g4x_get_aux_send_ctl;
684 
685 	drm_dp_aux_init(&intel_dp->aux);
686 
687 	/* Failure to allocate our preferred name is not critical */
688 	if (INTEL_GEN(dev_priv) >= 12 && aux_ch >= AUX_CH_USBC1)
689 		intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX USBC%c/%s",
690 					       aux_ch - AUX_CH_USBC1 + '1',
691 					       encoder->base.name);
692 	else
693 		intel_dp->aux.name = kasprintf(GFP_KERNEL, "AUX %c/%s",
694 					       aux_ch_name(aux_ch),
695 					       encoder->base.name);
696 
697 	intel_dp->aux.transfer = intel_dp_aux_transfer;
698 	cpu_latency_qos_add_request(&intel_dp->pm_qos, PM_QOS_DEFAULT_VALUE);
699 }
700