xref: /linux/drivers/gpu/drm/bridge/cadence/cdns-mhdp8546-core.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cadence MHDP8546 DP bridge driver.
4  *
5  * Copyright (C) 2020 Cadence Design Systems, Inc.
6  *
7  * Authors: Quentin Schulz <quentin.schulz@free-electrons.com>
8  *          Swapnil Jakhade <sjakhade@cadence.com>
9  *          Yuti Amonkar <yamonkar@cadence.com>
10  *          Tomi Valkeinen <tomi.valkeinen@ti.com>
11  *          Jyri Sarha <jsarha@ti.com>
12  *
13  * TODO:
14  *     - Implement optimized mailbox communication using mailbox interrupts
15  *     - Add support for power management
16  *     - Add support for features like audio, MST and fast link training
17  *     - Implement request_fw_cancel to handle HW_STATE
18  *     - Fix asynchronous loading of firmware implementation
19  *     - Add DRM helper function for cdns_mhdp_lower_link_rate
20  */
21 
22 #include <linux/clk.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/firmware.h>
26 #include <linux/io.h>
27 #include <linux/iopoll.h>
28 #include <linux/irq.h>
29 #include <linux/media-bus-format.h>
30 #include <linux/module.h>
31 #include <linux/of.h>
32 #include <linux/phy/phy.h>
33 #include <linux/phy/phy-dp.h>
34 #include <linux/platform_device.h>
35 #include <linux/slab.h>
36 #include <linux/wait.h>
37 
38 #include <drm/display/drm_dp_helper.h>
39 #include <drm/display/drm_hdcp_helper.h>
40 #include <drm/drm_atomic.h>
41 #include <drm/drm_atomic_helper.h>
42 #include <drm/drm_atomic_state_helper.h>
43 #include <drm/drm_bridge.h>
44 #include <drm/drm_connector.h>
45 #include <drm/drm_edid.h>
46 #include <drm/drm_modeset_helper_vtables.h>
47 #include <drm/drm_print.h>
48 #include <drm/drm_probe_helper.h>
49 
50 #include <linux/unaligned.h>
51 
52 #include "cdns-mhdp8546-core.h"
53 #include "cdns-mhdp8546-hdcp.h"
54 #include "cdns-mhdp8546-j721e.h"
55 
56 static void cdns_mhdp_bridge_hpd_enable(struct drm_bridge *bridge)
57 {
58 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
59 
60 	/* Enable SW event interrupts */
61 	if (mhdp->bridge_attached)
62 		writel(readl(mhdp->regs + CDNS_APB_INT_MASK) &
63 		       ~CDNS_APB_INT_MASK_SW_EVENT_INT,
64 		       mhdp->regs + CDNS_APB_INT_MASK);
65 }
66 
67 static void cdns_mhdp_bridge_hpd_disable(struct drm_bridge *bridge)
68 {
69 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
70 
71 	writel(readl(mhdp->regs + CDNS_APB_INT_MASK) |
72 	       CDNS_APB_INT_MASK_SW_EVENT_INT,
73 	       mhdp->regs + CDNS_APB_INT_MASK);
74 }
75 
76 static int cdns_mhdp_mailbox_read(struct cdns_mhdp_device *mhdp)
77 {
78 	int ret, empty;
79 
80 	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
81 
82 	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_EMPTY,
83 				 empty, !empty, MAILBOX_RETRY_US,
84 				 MAILBOX_TIMEOUT_US);
85 	if (ret < 0)
86 		return ret;
87 
88 	return readl(mhdp->regs + CDNS_MAILBOX_RX_DATA) & 0xff;
89 }
90 
91 static int cdns_mhdp_mailbox_write(struct cdns_mhdp_device *mhdp, u8 val)
92 {
93 	int ret, full;
94 
95 	WARN_ON(!mutex_is_locked(&mhdp->mbox_mutex));
96 
97 	ret = readx_poll_timeout(readl, mhdp->regs + CDNS_MAILBOX_FULL,
98 				 full, !full, MAILBOX_RETRY_US,
99 				 MAILBOX_TIMEOUT_US);
100 	if (ret < 0)
101 		return ret;
102 
103 	writel(val, mhdp->regs + CDNS_MAILBOX_TX_DATA);
104 
105 	return 0;
106 }
107 
108 static int cdns_mhdp_mailbox_recv_header(struct cdns_mhdp_device *mhdp,
109 					 u8 module_id, u8 opcode,
110 					 u16 req_size)
111 {
112 	u32 mbox_size, i;
113 	u8 header[4];
114 	int ret;
115 
116 	/* read the header of the message */
117 	for (i = 0; i < sizeof(header); i++) {
118 		ret = cdns_mhdp_mailbox_read(mhdp);
119 		if (ret < 0)
120 			return ret;
121 
122 		header[i] = ret;
123 	}
124 
125 	mbox_size = get_unaligned_be16(header + 2);
126 
127 	if (opcode != header[0] || module_id != header[1] ||
128 	    req_size != mbox_size) {
129 		/*
130 		 * If the message in mailbox is not what we want, we need to
131 		 * clear the mailbox by reading its contents.
132 		 */
133 		for (i = 0; i < mbox_size; i++)
134 			if (cdns_mhdp_mailbox_read(mhdp) < 0)
135 				break;
136 
137 		return -EINVAL;
138 	}
139 
140 	return 0;
141 }
142 
143 static int cdns_mhdp_mailbox_recv_data(struct cdns_mhdp_device *mhdp,
144 				       u8 *buff, u16 buff_size)
145 {
146 	u32 i;
147 	int ret;
148 
149 	for (i = 0; i < buff_size; i++) {
150 		ret = cdns_mhdp_mailbox_read(mhdp);
151 		if (ret < 0)
152 			return ret;
153 
154 		buff[i] = ret;
155 	}
156 
157 	return 0;
158 }
159 
160 static int cdns_mhdp_mailbox_send(struct cdns_mhdp_device *mhdp, u8 module_id,
161 				  u8 opcode, u16 size, u8 *message)
162 {
163 	u8 header[4];
164 	int ret, i;
165 
166 	header[0] = opcode;
167 	header[1] = module_id;
168 	put_unaligned_be16(size, header + 2);
169 
170 	for (i = 0; i < sizeof(header); i++) {
171 		ret = cdns_mhdp_mailbox_write(mhdp, header[i]);
172 		if (ret)
173 			return ret;
174 	}
175 
176 	for (i = 0; i < size; i++) {
177 		ret = cdns_mhdp_mailbox_write(mhdp, message[i]);
178 		if (ret)
179 			return ret;
180 	}
181 
182 	return 0;
183 }
184 
185 static
186 int cdns_mhdp_reg_read(struct cdns_mhdp_device *mhdp, u32 addr, u32 *value)
187 {
188 	u8 msg[4], resp[8];
189 	int ret;
190 
191 	put_unaligned_be32(addr, msg);
192 
193 	mutex_lock(&mhdp->mbox_mutex);
194 
195 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_GENERAL,
196 				     GENERAL_REGISTER_READ,
197 				     sizeof(msg), msg);
198 	if (ret)
199 		goto out;
200 
201 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_GENERAL,
202 					    GENERAL_REGISTER_READ,
203 					    sizeof(resp));
204 	if (ret)
205 		goto out;
206 
207 	ret = cdns_mhdp_mailbox_recv_data(mhdp, resp, sizeof(resp));
208 	if (ret)
209 		goto out;
210 
211 	/* Returned address value should be the same as requested */
212 	if (memcmp(msg, resp, sizeof(msg))) {
213 		ret = -EINVAL;
214 		goto out;
215 	}
216 
217 	*value = get_unaligned_be32(resp + 4);
218 
219 out:
220 	mutex_unlock(&mhdp->mbox_mutex);
221 	if (ret) {
222 		dev_err(mhdp->dev, "Failed to read register\n");
223 		*value = 0;
224 	}
225 
226 	return ret;
227 }
228 
229 static
230 int cdns_mhdp_reg_write(struct cdns_mhdp_device *mhdp, u16 addr, u32 val)
231 {
232 	u8 msg[6];
233 	int ret;
234 
235 	put_unaligned_be16(addr, msg);
236 	put_unaligned_be32(val, msg + 2);
237 
238 	mutex_lock(&mhdp->mbox_mutex);
239 
240 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
241 				     DPTX_WRITE_REGISTER, sizeof(msg), msg);
242 
243 	mutex_unlock(&mhdp->mbox_mutex);
244 
245 	return ret;
246 }
247 
248 static
249 int cdns_mhdp_reg_write_bit(struct cdns_mhdp_device *mhdp, u16 addr,
250 			    u8 start_bit, u8 bits_no, u32 val)
251 {
252 	u8 field[8];
253 	int ret;
254 
255 	put_unaligned_be16(addr, field);
256 	field[2] = start_bit;
257 	field[3] = bits_no;
258 	put_unaligned_be32(val, field + 4);
259 
260 	mutex_lock(&mhdp->mbox_mutex);
261 
262 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
263 				     DPTX_WRITE_FIELD, sizeof(field), field);
264 
265 	mutex_unlock(&mhdp->mbox_mutex);
266 
267 	return ret;
268 }
269 
270 static
271 int cdns_mhdp_dpcd_read(struct cdns_mhdp_device *mhdp,
272 			u32 addr, u8 *data, u16 len)
273 {
274 	u8 msg[5], reg[5];
275 	int ret;
276 
277 	put_unaligned_be16(len, msg);
278 	put_unaligned_be24(addr, msg + 2);
279 
280 	mutex_lock(&mhdp->mbox_mutex);
281 
282 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
283 				     DPTX_READ_DPCD, sizeof(msg), msg);
284 	if (ret)
285 		goto out;
286 
287 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
288 					    DPTX_READ_DPCD,
289 					    sizeof(reg) + len);
290 	if (ret)
291 		goto out;
292 
293 	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
294 	if (ret)
295 		goto out;
296 
297 	ret = cdns_mhdp_mailbox_recv_data(mhdp, data, len);
298 
299 out:
300 	mutex_unlock(&mhdp->mbox_mutex);
301 
302 	return ret;
303 }
304 
305 static
306 int cdns_mhdp_dpcd_write(struct cdns_mhdp_device *mhdp, u32 addr, u8 value)
307 {
308 	u8 msg[6], reg[5];
309 	int ret;
310 
311 	put_unaligned_be16(1, msg);
312 	put_unaligned_be24(addr, msg + 2);
313 	msg[5] = value;
314 
315 	mutex_lock(&mhdp->mbox_mutex);
316 
317 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
318 				     DPTX_WRITE_DPCD, sizeof(msg), msg);
319 	if (ret)
320 		goto out;
321 
322 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
323 					    DPTX_WRITE_DPCD, sizeof(reg));
324 	if (ret)
325 		goto out;
326 
327 	ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
328 	if (ret)
329 		goto out;
330 
331 	if (addr != get_unaligned_be24(reg + 2))
332 		ret = -EINVAL;
333 
334 out:
335 	mutex_unlock(&mhdp->mbox_mutex);
336 
337 	if (ret)
338 		dev_err(mhdp->dev, "dpcd write failed: %d\n", ret);
339 	return ret;
340 }
341 
342 static
343 int cdns_mhdp_set_firmware_active(struct cdns_mhdp_device *mhdp, bool enable)
344 {
345 	u8 msg[5];
346 	int ret, i;
347 
348 	msg[0] = GENERAL_MAIN_CONTROL;
349 	msg[1] = MB_MODULE_ID_GENERAL;
350 	msg[2] = 0;
351 	msg[3] = 1;
352 	msg[4] = enable ? FW_ACTIVE : FW_STANDBY;
353 
354 	mutex_lock(&mhdp->mbox_mutex);
355 
356 	for (i = 0; i < sizeof(msg); i++) {
357 		ret = cdns_mhdp_mailbox_write(mhdp, msg[i]);
358 		if (ret)
359 			goto out;
360 	}
361 
362 	/* read the firmware state */
363 	ret = cdns_mhdp_mailbox_recv_data(mhdp, msg, sizeof(msg));
364 	if (ret)
365 		goto out;
366 
367 	ret = 0;
368 
369 out:
370 	mutex_unlock(&mhdp->mbox_mutex);
371 
372 	if (ret < 0)
373 		dev_err(mhdp->dev, "set firmware active failed\n");
374 	return ret;
375 }
376 
377 static
378 int cdns_mhdp_get_hpd_status(struct cdns_mhdp_device *mhdp)
379 {
380 	u8 status;
381 	int ret;
382 
383 	mutex_lock(&mhdp->mbox_mutex);
384 
385 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
386 				     DPTX_HPD_STATE, 0, NULL);
387 	if (ret)
388 		goto err_get_hpd;
389 
390 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
391 					    DPTX_HPD_STATE,
392 					    sizeof(status));
393 	if (ret)
394 		goto err_get_hpd;
395 
396 	ret = cdns_mhdp_mailbox_recv_data(mhdp, &status, sizeof(status));
397 	if (ret)
398 		goto err_get_hpd;
399 
400 	mutex_unlock(&mhdp->mbox_mutex);
401 
402 	dev_dbg(mhdp->dev, "%s: HPD %splugged\n", __func__,
403 		status ? "" : "un");
404 
405 	return status;
406 
407 err_get_hpd:
408 	mutex_unlock(&mhdp->mbox_mutex);
409 
410 	return ret;
411 }
412 
413 static
414 int cdns_mhdp_get_edid_block(void *data, u8 *edid,
415 			     unsigned int block, size_t length)
416 {
417 	struct cdns_mhdp_device *mhdp = data;
418 	u8 msg[2], reg[2], i;
419 	int ret;
420 
421 	mutex_lock(&mhdp->mbox_mutex);
422 
423 	for (i = 0; i < 4; i++) {
424 		msg[0] = block / 2;
425 		msg[1] = block % 2;
426 
427 		ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
428 					     DPTX_GET_EDID, sizeof(msg), msg);
429 		if (ret)
430 			continue;
431 
432 		ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
433 						    DPTX_GET_EDID,
434 						    sizeof(reg) + length);
435 		if (ret)
436 			continue;
437 
438 		ret = cdns_mhdp_mailbox_recv_data(mhdp, reg, sizeof(reg));
439 		if (ret)
440 			continue;
441 
442 		ret = cdns_mhdp_mailbox_recv_data(mhdp, edid, length);
443 		if (ret)
444 			continue;
445 
446 		if (reg[0] == length && reg[1] == block / 2)
447 			break;
448 	}
449 
450 	mutex_unlock(&mhdp->mbox_mutex);
451 
452 	if (ret)
453 		dev_err(mhdp->dev, "get block[%d] edid failed: %d\n",
454 			block, ret);
455 
456 	return ret;
457 }
458 
459 static
460 int cdns_mhdp_read_hpd_event(struct cdns_mhdp_device *mhdp)
461 {
462 	u8 event = 0;
463 	int ret;
464 
465 	mutex_lock(&mhdp->mbox_mutex);
466 
467 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
468 				     DPTX_READ_EVENT, 0, NULL);
469 	if (ret)
470 		goto out;
471 
472 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
473 					    DPTX_READ_EVENT, sizeof(event));
474 	if (ret < 0)
475 		goto out;
476 
477 	ret = cdns_mhdp_mailbox_recv_data(mhdp, &event, sizeof(event));
478 out:
479 	mutex_unlock(&mhdp->mbox_mutex);
480 
481 	if (ret < 0)
482 		return ret;
483 
484 	dev_dbg(mhdp->dev, "%s: %s%s%s%s\n", __func__,
485 		(event & DPTX_READ_EVENT_HPD_TO_HIGH) ? "TO_HIGH " : "",
486 		(event & DPTX_READ_EVENT_HPD_TO_LOW) ? "TO_LOW " : "",
487 		(event & DPTX_READ_EVENT_HPD_PULSE) ? "PULSE " : "",
488 		(event & DPTX_READ_EVENT_HPD_STATE) ? "HPD_STATE " : "");
489 
490 	return event;
491 }
492 
493 static
494 int cdns_mhdp_adjust_lt(struct cdns_mhdp_device *mhdp, unsigned int nlanes,
495 			unsigned int udelay, const u8 *lanes_data,
496 			u8 link_status[DP_LINK_STATUS_SIZE])
497 {
498 	u8 payload[7];
499 	u8 hdr[5]; /* For DPCD read response header */
500 	u32 addr;
501 	int ret;
502 
503 	if (nlanes != 4 && nlanes != 2 && nlanes != 1) {
504 		dev_err(mhdp->dev, "invalid number of lanes: %u\n", nlanes);
505 		ret = -EINVAL;
506 		goto out;
507 	}
508 
509 	payload[0] = nlanes;
510 	put_unaligned_be16(udelay, payload + 1);
511 	memcpy(payload + 3, lanes_data, nlanes);
512 
513 	mutex_lock(&mhdp->mbox_mutex);
514 
515 	ret = cdns_mhdp_mailbox_send(mhdp, MB_MODULE_ID_DP_TX,
516 				     DPTX_ADJUST_LT,
517 				     sizeof(payload), payload);
518 	if (ret)
519 		goto out;
520 
521 	/* Yes, read the DPCD read command response */
522 	ret = cdns_mhdp_mailbox_recv_header(mhdp, MB_MODULE_ID_DP_TX,
523 					    DPTX_READ_DPCD,
524 					    sizeof(hdr) + DP_LINK_STATUS_SIZE);
525 	if (ret)
526 		goto out;
527 
528 	ret = cdns_mhdp_mailbox_recv_data(mhdp, hdr, sizeof(hdr));
529 	if (ret)
530 		goto out;
531 
532 	addr = get_unaligned_be24(hdr + 2);
533 	if (addr != DP_LANE0_1_STATUS)
534 		goto out;
535 
536 	ret = cdns_mhdp_mailbox_recv_data(mhdp, link_status,
537 					  DP_LINK_STATUS_SIZE);
538 
539 out:
540 	mutex_unlock(&mhdp->mbox_mutex);
541 
542 	if (ret)
543 		dev_err(mhdp->dev, "Failed to adjust Link Training.\n");
544 
545 	return ret;
546 }
547 
548 /**
549  * cdns_mhdp_link_power_up() - power up a DisplayPort link
550  * @aux: DisplayPort AUX channel
551  * @link: pointer to a structure containing the link configuration
552  *
553  * Returns 0 on success or a negative error code on failure.
554  */
555 static
556 int cdns_mhdp_link_power_up(struct drm_dp_aux *aux, struct cdns_mhdp_link *link)
557 {
558 	u8 value;
559 	int err;
560 
561 	/* DP_SET_POWER register is only available on DPCD v1.1 and later */
562 	if (link->revision < 0x11)
563 		return 0;
564 
565 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
566 	if (err < 0)
567 		return err;
568 
569 	value &= ~DP_SET_POWER_MASK;
570 	value |= DP_SET_POWER_D0;
571 
572 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
573 	if (err < 0)
574 		return err;
575 
576 	/*
577 	 * According to the DP 1.1 specification, a "Sink Device must exit the
578 	 * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink
579 	 * Control Field" (register 0x600).
580 	 */
581 	usleep_range(1000, 2000);
582 
583 	return 0;
584 }
585 
586 /**
587  * cdns_mhdp_link_power_down() - power down a DisplayPort link
588  * @aux: DisplayPort AUX channel
589  * @link: pointer to a structure containing the link configuration
590  *
591  * Returns 0 on success or a negative error code on failure.
592  */
593 static
594 int cdns_mhdp_link_power_down(struct drm_dp_aux *aux,
595 			      struct cdns_mhdp_link *link)
596 {
597 	u8 value;
598 	int err;
599 
600 	/* DP_SET_POWER register is only available on DPCD v1.1 and later */
601 	if (link->revision < 0x11)
602 		return 0;
603 
604 	err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value);
605 	if (err < 0)
606 		return err;
607 
608 	value &= ~DP_SET_POWER_MASK;
609 	value |= DP_SET_POWER_D3;
610 
611 	err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value);
612 	if (err < 0)
613 		return err;
614 
615 	return 0;
616 }
617 
618 /**
619  * cdns_mhdp_link_configure() - configure a DisplayPort link
620  * @aux: DisplayPort AUX channel
621  * @link: pointer to a structure containing the link configuration
622  *
623  * Returns 0 on success or a negative error code on failure.
624  */
625 static
626 int cdns_mhdp_link_configure(struct drm_dp_aux *aux,
627 			     struct cdns_mhdp_link *link)
628 {
629 	u8 values[2];
630 	int err;
631 
632 	values[0] = drm_dp_link_rate_to_bw_code(link->rate);
633 	values[1] = link->num_lanes;
634 
635 	if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING)
636 		values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
637 
638 	err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values));
639 	if (err < 0)
640 		return err;
641 
642 	return 0;
643 }
644 
645 static unsigned int cdns_mhdp_max_link_rate(struct cdns_mhdp_device *mhdp)
646 {
647 	return min(mhdp->host.link_rate, mhdp->sink.link_rate);
648 }
649 
650 static u8 cdns_mhdp_max_num_lanes(struct cdns_mhdp_device *mhdp)
651 {
652 	return min(mhdp->sink.lanes_cnt, mhdp->host.lanes_cnt);
653 }
654 
655 static u8 cdns_mhdp_eq_training_pattern_supported(struct cdns_mhdp_device *mhdp)
656 {
657 	return fls(mhdp->host.pattern_supp & mhdp->sink.pattern_supp);
658 }
659 
660 static bool cdns_mhdp_get_ssc_supported(struct cdns_mhdp_device *mhdp)
661 {
662 	/* Check if SSC is supported by both sides */
663 	return mhdp->host.ssc && mhdp->sink.ssc;
664 }
665 
666 static enum drm_connector_status cdns_mhdp_detect(struct cdns_mhdp_device *mhdp)
667 {
668 	dev_dbg(mhdp->dev, "%s: %d\n", __func__, mhdp->plugged);
669 
670 	if (mhdp->plugged)
671 		return connector_status_connected;
672 	else
673 		return connector_status_disconnected;
674 }
675 
676 static int cdns_mhdp_check_fw_version(struct cdns_mhdp_device *mhdp)
677 {
678 	u32 major_num, minor_num, revision;
679 	u32 fw_ver, lib_ver;
680 
681 	fw_ver = (readl(mhdp->regs + CDNS_VER_H) << 8)
682 	       | readl(mhdp->regs + CDNS_VER_L);
683 
684 	lib_ver = (readl(mhdp->regs + CDNS_LIB_H_ADDR) << 8)
685 		| readl(mhdp->regs + CDNS_LIB_L_ADDR);
686 
687 	if (lib_ver < 33984) {
688 		/*
689 		 * Older FW versions with major number 1, used to store FW
690 		 * version information by storing repository revision number
691 		 * in registers. This is for identifying these FW versions.
692 		 */
693 		major_num = 1;
694 		minor_num = 2;
695 		if (fw_ver == 26098) {
696 			revision = 15;
697 		} else if (lib_ver == 0 && fw_ver == 0) {
698 			revision = 17;
699 		} else {
700 			dev_err(mhdp->dev, "Unsupported FW version: fw_ver = %u, lib_ver = %u\n",
701 				fw_ver, lib_ver);
702 			return -ENODEV;
703 		}
704 	} else {
705 		/* To identify newer FW versions with major number 2 onwards. */
706 		major_num = fw_ver / 10000;
707 		minor_num = (fw_ver / 100) % 100;
708 		revision = (fw_ver % 10000) % 100;
709 	}
710 
711 	dev_dbg(mhdp->dev, "FW version: v%u.%u.%u\n", major_num, minor_num,
712 		revision);
713 	return 0;
714 }
715 
716 static int cdns_mhdp_fw_activate(const struct firmware *fw,
717 				 struct cdns_mhdp_device *mhdp)
718 {
719 	unsigned int reg;
720 	int ret;
721 
722 	/* Release uCPU reset and stall it. */
723 	writel(CDNS_CPU_STALL, mhdp->regs + CDNS_APB_CTRL);
724 
725 	memcpy_toio(mhdp->regs + CDNS_MHDP_IMEM, fw->data, fw->size);
726 
727 	/* Leave debug mode, release stall */
728 	writel(0, mhdp->regs + CDNS_APB_CTRL);
729 
730 	/*
731 	 * Wait for the KEEP_ALIVE "message" on the first 8 bits.
732 	 * Updated each sched "tick" (~2ms)
733 	 */
734 	ret = readl_poll_timeout(mhdp->regs + CDNS_KEEP_ALIVE, reg,
735 				 reg & CDNS_KEEP_ALIVE_MASK, 500,
736 				 CDNS_KEEP_ALIVE_TIMEOUT);
737 	if (ret) {
738 		dev_err(mhdp->dev,
739 			"device didn't give any life sign: reg %d\n", reg);
740 		return ret;
741 	}
742 
743 	ret = cdns_mhdp_check_fw_version(mhdp);
744 	if (ret)
745 		return ret;
746 
747 	/* Init events to 0 as it's not cleared by FW at boot but on read */
748 	readl(mhdp->regs + CDNS_SW_EVENT0);
749 	readl(mhdp->regs + CDNS_SW_EVENT1);
750 	readl(mhdp->regs + CDNS_SW_EVENT2);
751 	readl(mhdp->regs + CDNS_SW_EVENT3);
752 
753 	/* Activate uCPU */
754 	ret = cdns_mhdp_set_firmware_active(mhdp, true);
755 	if (ret)
756 		return ret;
757 
758 	spin_lock(&mhdp->start_lock);
759 
760 	mhdp->hw_state = MHDP_HW_READY;
761 
762 	/*
763 	 * Here we must keep the lock while enabling the interrupts
764 	 * since it would otherwise be possible that interrupt enable
765 	 * code is executed after the bridge is detached. The similar
766 	 * situation is not possible in attach()/detach() callbacks
767 	 * since the hw_state changes from MHDP_HW_READY to
768 	 * MHDP_HW_STOPPED happens only due to driver removal when
769 	 * bridge should already be detached.
770 	 */
771 	cdns_mhdp_bridge_hpd_enable(&mhdp->bridge);
772 
773 	spin_unlock(&mhdp->start_lock);
774 
775 	wake_up(&mhdp->fw_load_wq);
776 	dev_dbg(mhdp->dev, "DP FW activated\n");
777 
778 	return 0;
779 }
780 
781 static void cdns_mhdp_fw_cb(const struct firmware *fw, void *context)
782 {
783 	struct cdns_mhdp_device *mhdp = context;
784 	bool bridge_attached;
785 	int ret;
786 
787 	dev_dbg(mhdp->dev, "firmware callback\n");
788 
789 	if (!fw || !fw->data) {
790 		dev_err(mhdp->dev, "%s: No firmware.\n", __func__);
791 		return;
792 	}
793 
794 	ret = cdns_mhdp_fw_activate(fw, mhdp);
795 
796 	release_firmware(fw);
797 
798 	if (ret)
799 		return;
800 
801 	/*
802 	 *  XXX how to make sure the bridge is still attached when
803 	 *      calling drm_kms_helper_hotplug_event() after releasing
804 	 *      the lock? We should not hold the spin lock when
805 	 *      calling drm_kms_helper_hotplug_event() since it may
806 	 *      cause a dead lock. FB-dev console calls detect from the
807 	 *      same thread just down the call stack started here.
808 	 */
809 	spin_lock(&mhdp->start_lock);
810 	bridge_attached = mhdp->bridge_attached;
811 	spin_unlock(&mhdp->start_lock);
812 	if (bridge_attached) {
813 		if (mhdp->connector.dev)
814 			drm_kms_helper_hotplug_event(mhdp->bridge.dev);
815 		else
816 			drm_bridge_hpd_notify(&mhdp->bridge, cdns_mhdp_detect(mhdp));
817 	}
818 }
819 
820 static int cdns_mhdp_load_firmware(struct cdns_mhdp_device *mhdp)
821 {
822 	int ret;
823 
824 	ret = request_firmware_nowait(THIS_MODULE, true, FW_NAME, mhdp->dev,
825 				      GFP_KERNEL, mhdp, cdns_mhdp_fw_cb);
826 	if (ret) {
827 		dev_err(mhdp->dev, "failed to load firmware (%s), ret: %d\n",
828 			FW_NAME, ret);
829 		return ret;
830 	}
831 
832 	return 0;
833 }
834 
835 static ssize_t cdns_mhdp_transfer(struct drm_dp_aux *aux,
836 				  struct drm_dp_aux_msg *msg)
837 {
838 	struct cdns_mhdp_device *mhdp = dev_get_drvdata(aux->dev);
839 	int ret;
840 
841 	if (msg->request != DP_AUX_NATIVE_WRITE &&
842 	    msg->request != DP_AUX_NATIVE_READ)
843 		return -EOPNOTSUPP;
844 
845 	if (msg->request == DP_AUX_NATIVE_WRITE) {
846 		const u8 *buf = msg->buffer;
847 		unsigned int i;
848 
849 		for (i = 0; i < msg->size; ++i) {
850 			ret = cdns_mhdp_dpcd_write(mhdp,
851 						   msg->address + i, buf[i]);
852 			if (!ret)
853 				continue;
854 
855 			dev_err(mhdp->dev,
856 				"Failed to write DPCD addr %u\n",
857 				msg->address + i);
858 
859 			return ret;
860 		}
861 	} else {
862 		ret = cdns_mhdp_dpcd_read(mhdp, msg->address,
863 					  msg->buffer, msg->size);
864 		if (ret) {
865 			dev_err(mhdp->dev,
866 				"Failed to read DPCD addr %u\n",
867 				msg->address);
868 
869 			return ret;
870 		}
871 	}
872 
873 	return msg->size;
874 }
875 
876 static int cdns_mhdp_link_training_init(struct cdns_mhdp_device *mhdp)
877 {
878 	union phy_configure_opts phy_cfg;
879 	u32 reg32;
880 	int ret;
881 
882 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
883 			   DP_TRAINING_PATTERN_DISABLE);
884 
885 	/* Reset PHY configuration */
886 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
887 	if (!mhdp->host.scrambler)
888 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
889 
890 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
891 
892 	cdns_mhdp_reg_write(mhdp, CDNS_DP_ENHNCD,
893 			    mhdp->sink.enhanced & mhdp->host.enhanced);
894 
895 	cdns_mhdp_reg_write(mhdp, CDNS_DP_LANE_EN,
896 			    CDNS_DP_LANE_EN_LANES(mhdp->link.num_lanes));
897 
898 	cdns_mhdp_link_configure(&mhdp->aux, &mhdp->link);
899 	phy_cfg.dp.link_rate = mhdp->link.rate / 100;
900 	phy_cfg.dp.lanes = mhdp->link.num_lanes;
901 
902 	memset(phy_cfg.dp.voltage, 0, sizeof(phy_cfg.dp.voltage));
903 	memset(phy_cfg.dp.pre, 0, sizeof(phy_cfg.dp.pre));
904 
905 	phy_cfg.dp.ssc = cdns_mhdp_get_ssc_supported(mhdp);
906 	phy_cfg.dp.set_lanes = true;
907 	phy_cfg.dp.set_rate = true;
908 	phy_cfg.dp.set_voltages = true;
909 	ret = phy_configure(mhdp->phy,  &phy_cfg);
910 	if (ret) {
911 		dev_err(mhdp->dev, "%s: phy_configure() failed: %d\n",
912 			__func__, ret);
913 		return ret;
914 	}
915 
916 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG,
917 			    CDNS_PHY_COMMON_CONFIG |
918 			    CDNS_PHY_TRAINING_EN |
919 			    CDNS_PHY_TRAINING_TYPE(1) |
920 			    CDNS_PHY_SCRAMBLER_BYPASS);
921 
922 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
923 			   DP_TRAINING_PATTERN_1 | DP_LINK_SCRAMBLING_DISABLE);
924 
925 	return 0;
926 }
927 
928 static void cdns_mhdp_get_adjust_train(struct cdns_mhdp_device *mhdp,
929 				       u8 link_status[DP_LINK_STATUS_SIZE],
930 				       u8 lanes_data[CDNS_DP_MAX_NUM_LANES],
931 				       union phy_configure_opts *phy_cfg)
932 {
933 	u8 adjust, max_pre_emph, max_volt_swing;
934 	u8 set_volt, set_pre;
935 	unsigned int i;
936 
937 	max_pre_emph = CDNS_PRE_EMPHASIS(mhdp->host.pre_emphasis)
938 			   << DP_TRAIN_PRE_EMPHASIS_SHIFT;
939 	max_volt_swing = CDNS_VOLT_SWING(mhdp->host.volt_swing);
940 
941 	for (i = 0; i < mhdp->link.num_lanes; i++) {
942 		/* Check if Voltage swing and pre-emphasis are within limits */
943 		adjust = drm_dp_get_adjust_request_voltage(link_status, i);
944 		set_volt = min(adjust, max_volt_swing);
945 
946 		adjust = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
947 		set_pre = min(adjust, max_pre_emph)
948 			  >> DP_TRAIN_PRE_EMPHASIS_SHIFT;
949 
950 		/*
951 		 * Voltage swing level and pre-emphasis level combination is
952 		 * not allowed: leaving pre-emphasis as-is, and adjusting
953 		 * voltage swing.
954 		 */
955 		if (set_volt + set_pre > 3)
956 			set_volt = 3 - set_pre;
957 
958 		phy_cfg->dp.voltage[i] = set_volt;
959 		lanes_data[i] = set_volt;
960 
961 		if (set_volt == max_volt_swing)
962 			lanes_data[i] |= DP_TRAIN_MAX_SWING_REACHED;
963 
964 		phy_cfg->dp.pre[i] = set_pre;
965 		lanes_data[i] |= (set_pre << DP_TRAIN_PRE_EMPHASIS_SHIFT);
966 
967 		if (set_pre == (max_pre_emph >> DP_TRAIN_PRE_EMPHASIS_SHIFT))
968 			lanes_data[i] |= DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
969 	}
970 }
971 
972 static
973 void cdns_mhdp_set_adjust_request_voltage(u8 link_status[DP_LINK_STATUS_SIZE],
974 					  unsigned int lane, u8 volt)
975 {
976 	unsigned int s = ((lane & 1) ?
977 			  DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
978 			  DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
979 	unsigned int idx = DP_ADJUST_REQUEST_LANE0_1 - DP_LANE0_1_STATUS + (lane >> 1);
980 
981 	link_status[idx] &= ~(DP_ADJUST_VOLTAGE_SWING_LANE0_MASK << s);
982 	link_status[idx] |= volt << s;
983 }
984 
985 static
986 void cdns_mhdp_set_adjust_request_pre_emphasis(u8 link_status[DP_LINK_STATUS_SIZE],
987 					       unsigned int lane, u8 pre_emphasis)
988 {
989 	unsigned int s = ((lane & 1) ?
990 			  DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
991 			  DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
992 	unsigned int idx = DP_ADJUST_REQUEST_LANE0_1 - DP_LANE0_1_STATUS + (lane >> 1);
993 
994 	link_status[idx] &= ~(DP_ADJUST_PRE_EMPHASIS_LANE0_MASK << s);
995 	link_status[idx] |= pre_emphasis << s;
996 }
997 
998 static void cdns_mhdp_adjust_requested_eq(struct cdns_mhdp_device *mhdp,
999 					  u8 link_status[DP_LINK_STATUS_SIZE])
1000 {
1001 	u8 max_pre = CDNS_PRE_EMPHASIS(mhdp->host.pre_emphasis);
1002 	u8 max_volt = CDNS_VOLT_SWING(mhdp->host.volt_swing);
1003 	unsigned int i;
1004 	u8 volt, pre;
1005 
1006 	for (i = 0; i < mhdp->link.num_lanes; i++) {
1007 		volt = drm_dp_get_adjust_request_voltage(link_status, i);
1008 		pre = drm_dp_get_adjust_request_pre_emphasis(link_status, i);
1009 		if (volt + pre > 3)
1010 			cdns_mhdp_set_adjust_request_voltage(link_status, i,
1011 							     3 - pre);
1012 		if (mhdp->host.volt_swing & CDNS_FORCE_VOLT_SWING)
1013 			cdns_mhdp_set_adjust_request_voltage(link_status, i,
1014 							     max_volt);
1015 		if (mhdp->host.pre_emphasis & CDNS_FORCE_PRE_EMPHASIS)
1016 			cdns_mhdp_set_adjust_request_pre_emphasis(link_status,
1017 								  i, max_pre);
1018 	}
1019 }
1020 
1021 static void cdns_mhdp_print_lt_status(const char *prefix,
1022 				      struct cdns_mhdp_device *mhdp,
1023 				      union phy_configure_opts *phy_cfg)
1024 {
1025 	char vs[8] = "0/0/0/0";
1026 	char pe[8] = "0/0/0/0";
1027 	unsigned int i;
1028 
1029 	for (i = 0; i < mhdp->link.num_lanes; i++) {
1030 		vs[i * 2] = '0' + phy_cfg->dp.voltage[i];
1031 		pe[i * 2] = '0' + phy_cfg->dp.pre[i];
1032 	}
1033 
1034 	vs[i * 2 - 1] = '\0';
1035 	pe[i * 2 - 1] = '\0';
1036 
1037 	dev_dbg(mhdp->dev, "%s, %u lanes, %u Mbps, vs %s, pe %s\n",
1038 		prefix,
1039 		mhdp->link.num_lanes, mhdp->link.rate / 100,
1040 		vs, pe);
1041 }
1042 
1043 static bool cdns_mhdp_link_training_channel_eq(struct cdns_mhdp_device *mhdp,
1044 					       u8 eq_tps,
1045 					       unsigned int training_interval)
1046 {
1047 	u8 lanes_data[CDNS_DP_MAX_NUM_LANES], fail_counter_short = 0;
1048 	u8 link_status[DP_LINK_STATUS_SIZE];
1049 	union phy_configure_opts phy_cfg;
1050 	u32 reg32;
1051 	int ret;
1052 	bool r;
1053 
1054 	dev_dbg(mhdp->dev, "Starting EQ phase\n");
1055 
1056 	/* Enable link training TPS[eq_tps] in PHY */
1057 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_EN |
1058 		CDNS_PHY_TRAINING_TYPE(eq_tps);
1059 	if (eq_tps != 4)
1060 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
1061 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
1062 
1063 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
1064 			   (eq_tps != 4) ? eq_tps | DP_LINK_SCRAMBLING_DISABLE :
1065 			   CDNS_DP_TRAINING_PATTERN_4);
1066 
1067 	drm_dp_dpcd_read_link_status(&mhdp->aux, link_status);
1068 
1069 	do {
1070 		cdns_mhdp_get_adjust_train(mhdp, link_status, lanes_data,
1071 					   &phy_cfg);
1072 		phy_cfg.dp.lanes = mhdp->link.num_lanes;
1073 		phy_cfg.dp.ssc = cdns_mhdp_get_ssc_supported(mhdp);
1074 		phy_cfg.dp.set_lanes = false;
1075 		phy_cfg.dp.set_rate = false;
1076 		phy_cfg.dp.set_voltages = true;
1077 		ret = phy_configure(mhdp->phy,  &phy_cfg);
1078 		if (ret) {
1079 			dev_err(mhdp->dev, "%s: phy_configure() failed: %d\n",
1080 				__func__, ret);
1081 			goto err;
1082 		}
1083 
1084 		cdns_mhdp_adjust_lt(mhdp, mhdp->link.num_lanes,
1085 				    training_interval, lanes_data, link_status);
1086 
1087 		r = drm_dp_clock_recovery_ok(link_status, mhdp->link.num_lanes);
1088 		if (!r)
1089 			goto err;
1090 
1091 		if (drm_dp_channel_eq_ok(link_status, mhdp->link.num_lanes)) {
1092 			cdns_mhdp_print_lt_status("EQ phase ok", mhdp,
1093 						  &phy_cfg);
1094 			return true;
1095 		}
1096 
1097 		fail_counter_short++;
1098 
1099 		cdns_mhdp_adjust_requested_eq(mhdp, link_status);
1100 	} while (fail_counter_short < 5);
1101 
1102 err:
1103 	cdns_mhdp_print_lt_status("EQ phase failed", mhdp, &phy_cfg);
1104 
1105 	return false;
1106 }
1107 
1108 static void cdns_mhdp_adjust_requested_cr(struct cdns_mhdp_device *mhdp,
1109 					  u8 link_status[DP_LINK_STATUS_SIZE],
1110 					  u8 *req_volt, u8 *req_pre)
1111 {
1112 	const u8 max_volt = CDNS_VOLT_SWING(mhdp->host.volt_swing);
1113 	const u8 max_pre = CDNS_PRE_EMPHASIS(mhdp->host.pre_emphasis);
1114 	unsigned int i;
1115 
1116 	for (i = 0; i < mhdp->link.num_lanes; i++) {
1117 		u8 val;
1118 
1119 		val = mhdp->host.volt_swing & CDNS_FORCE_VOLT_SWING ?
1120 		      max_volt : req_volt[i];
1121 		cdns_mhdp_set_adjust_request_voltage(link_status, i, val);
1122 
1123 		val = mhdp->host.pre_emphasis & CDNS_FORCE_PRE_EMPHASIS ?
1124 		      max_pre : req_pre[i];
1125 		cdns_mhdp_set_adjust_request_pre_emphasis(link_status, i, val);
1126 	}
1127 }
1128 
1129 static
1130 void cdns_mhdp_validate_cr(struct cdns_mhdp_device *mhdp, bool *cr_done,
1131 			   bool *same_before_adjust, bool *max_swing_reached,
1132 			   u8 before_cr[CDNS_DP_MAX_NUM_LANES],
1133 			   u8 after_cr[DP_LINK_STATUS_SIZE], u8 *req_volt,
1134 			   u8 *req_pre)
1135 {
1136 	const u8 max_volt = CDNS_VOLT_SWING(mhdp->host.volt_swing);
1137 	const u8 max_pre = CDNS_PRE_EMPHASIS(mhdp->host.pre_emphasis);
1138 	bool same_pre, same_volt;
1139 	unsigned int i;
1140 	u8 adjust;
1141 
1142 	*same_before_adjust = false;
1143 	*max_swing_reached = false;
1144 	*cr_done = drm_dp_clock_recovery_ok(after_cr, mhdp->link.num_lanes);
1145 
1146 	for (i = 0; i < mhdp->link.num_lanes; i++) {
1147 		adjust = drm_dp_get_adjust_request_voltage(after_cr, i);
1148 		req_volt[i] = min(adjust, max_volt);
1149 
1150 		adjust = drm_dp_get_adjust_request_pre_emphasis(after_cr, i) >>
1151 		      DP_TRAIN_PRE_EMPHASIS_SHIFT;
1152 		req_pre[i] = min(adjust, max_pre);
1153 
1154 		same_pre = (before_cr[i] & DP_TRAIN_PRE_EMPHASIS_MASK) ==
1155 			   req_pre[i] << DP_TRAIN_PRE_EMPHASIS_SHIFT;
1156 		same_volt = (before_cr[i] & DP_TRAIN_VOLTAGE_SWING_MASK) ==
1157 			    req_volt[i];
1158 		if (same_pre && same_volt)
1159 			*same_before_adjust = true;
1160 
1161 		/* 3.1.5.2 in DP Standard v1.4. Table 3-1 */
1162 		if (!*cr_done && req_volt[i] + req_pre[i] >= 3) {
1163 			*max_swing_reached = true;
1164 			return;
1165 		}
1166 	}
1167 }
1168 
1169 static bool cdns_mhdp_link_training_cr(struct cdns_mhdp_device *mhdp)
1170 {
1171 	u8 lanes_data[CDNS_DP_MAX_NUM_LANES],
1172 	fail_counter_short = 0, fail_counter_cr_long = 0;
1173 	u8 link_status[DP_LINK_STATUS_SIZE];
1174 	bool cr_done;
1175 	union phy_configure_opts phy_cfg;
1176 	int ret;
1177 
1178 	dev_dbg(mhdp->dev, "Starting CR phase\n");
1179 
1180 	ret = cdns_mhdp_link_training_init(mhdp);
1181 	if (ret)
1182 		goto err;
1183 
1184 	drm_dp_dpcd_read_link_status(&mhdp->aux, link_status);
1185 
1186 	do {
1187 		u8 requested_adjust_volt_swing[CDNS_DP_MAX_NUM_LANES] = {};
1188 		u8 requested_adjust_pre_emphasis[CDNS_DP_MAX_NUM_LANES] = {};
1189 		bool same_before_adjust, max_swing_reached;
1190 
1191 		cdns_mhdp_get_adjust_train(mhdp, link_status, lanes_data,
1192 					   &phy_cfg);
1193 		phy_cfg.dp.lanes = mhdp->link.num_lanes;
1194 		phy_cfg.dp.ssc = cdns_mhdp_get_ssc_supported(mhdp);
1195 		phy_cfg.dp.set_lanes = false;
1196 		phy_cfg.dp.set_rate = false;
1197 		phy_cfg.dp.set_voltages = true;
1198 		ret = phy_configure(mhdp->phy,  &phy_cfg);
1199 		if (ret) {
1200 			dev_err(mhdp->dev, "%s: phy_configure() failed: %d\n",
1201 				__func__, ret);
1202 			goto err;
1203 		}
1204 
1205 		cdns_mhdp_adjust_lt(mhdp, mhdp->link.num_lanes, 100,
1206 				    lanes_data, link_status);
1207 
1208 		cdns_mhdp_validate_cr(mhdp, &cr_done, &same_before_adjust,
1209 				      &max_swing_reached, lanes_data,
1210 				      link_status,
1211 				      requested_adjust_volt_swing,
1212 				      requested_adjust_pre_emphasis);
1213 
1214 		if (max_swing_reached) {
1215 			dev_err(mhdp->dev, "CR: max swing reached\n");
1216 			goto err;
1217 		}
1218 
1219 		if (cr_done) {
1220 			cdns_mhdp_print_lt_status("CR phase ok", mhdp,
1221 						  &phy_cfg);
1222 			return true;
1223 		}
1224 
1225 		/* Not all CR_DONE bits set */
1226 		fail_counter_cr_long++;
1227 
1228 		if (same_before_adjust) {
1229 			fail_counter_short++;
1230 			continue;
1231 		}
1232 
1233 		fail_counter_short = 0;
1234 		/*
1235 		 * Voltage swing/pre-emphasis adjust requested
1236 		 * during CR phase
1237 		 */
1238 		cdns_mhdp_adjust_requested_cr(mhdp, link_status,
1239 					      requested_adjust_volt_swing,
1240 					      requested_adjust_pre_emphasis);
1241 	} while (fail_counter_short < 5 && fail_counter_cr_long < 10);
1242 
1243 err:
1244 	cdns_mhdp_print_lt_status("CR phase failed", mhdp, &phy_cfg);
1245 
1246 	return false;
1247 }
1248 
1249 static void cdns_mhdp_lower_link_rate(struct cdns_mhdp_link *link)
1250 {
1251 	switch (drm_dp_link_rate_to_bw_code(link->rate)) {
1252 	case DP_LINK_BW_2_7:
1253 		link->rate = drm_dp_bw_code_to_link_rate(DP_LINK_BW_1_62);
1254 		break;
1255 	case DP_LINK_BW_5_4:
1256 		link->rate = drm_dp_bw_code_to_link_rate(DP_LINK_BW_2_7);
1257 		break;
1258 	case DP_LINK_BW_8_1:
1259 		link->rate = drm_dp_bw_code_to_link_rate(DP_LINK_BW_5_4);
1260 		break;
1261 	}
1262 }
1263 
1264 static int cdns_mhdp_link_training(struct cdns_mhdp_device *mhdp,
1265 				   unsigned int training_interval)
1266 {
1267 	u32 reg32;
1268 	const u8 eq_tps = cdns_mhdp_eq_training_pattern_supported(mhdp);
1269 	int ret;
1270 
1271 	while (1) {
1272 		if (!cdns_mhdp_link_training_cr(mhdp)) {
1273 			if (drm_dp_link_rate_to_bw_code(mhdp->link.rate) !=
1274 			    DP_LINK_BW_1_62) {
1275 				dev_dbg(mhdp->dev,
1276 					"Reducing link rate during CR phase\n");
1277 				cdns_mhdp_lower_link_rate(&mhdp->link);
1278 
1279 				continue;
1280 			} else if (mhdp->link.num_lanes > 1) {
1281 				dev_dbg(mhdp->dev,
1282 					"Reducing lanes number during CR phase\n");
1283 				mhdp->link.num_lanes >>= 1;
1284 				mhdp->link.rate = cdns_mhdp_max_link_rate(mhdp);
1285 
1286 				continue;
1287 			}
1288 
1289 			dev_err(mhdp->dev,
1290 				"Link training failed during CR phase\n");
1291 			goto err;
1292 		}
1293 
1294 		if (cdns_mhdp_link_training_channel_eq(mhdp, eq_tps,
1295 						       training_interval))
1296 			break;
1297 
1298 		if (mhdp->link.num_lanes > 1) {
1299 			dev_dbg(mhdp->dev,
1300 				"Reducing lanes number during EQ phase\n");
1301 			mhdp->link.num_lanes >>= 1;
1302 
1303 			continue;
1304 		} else if (drm_dp_link_rate_to_bw_code(mhdp->link.rate) !=
1305 			   DP_LINK_BW_1_62) {
1306 			dev_dbg(mhdp->dev,
1307 				"Reducing link rate during EQ phase\n");
1308 			cdns_mhdp_lower_link_rate(&mhdp->link);
1309 			mhdp->link.num_lanes = cdns_mhdp_max_num_lanes(mhdp);
1310 
1311 			continue;
1312 		}
1313 
1314 		dev_err(mhdp->dev, "Link training failed during EQ phase\n");
1315 		goto err;
1316 	}
1317 
1318 	dev_dbg(mhdp->dev, "Link training ok. Lanes: %u, Rate %u Mbps\n",
1319 		mhdp->link.num_lanes, mhdp->link.rate / 100);
1320 
1321 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
1322 			   mhdp->host.scrambler ? 0 :
1323 			   DP_LINK_SCRAMBLING_DISABLE);
1324 
1325 	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &reg32);
1326 	if (ret < 0) {
1327 		dev_err(mhdp->dev,
1328 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
1329 			ret);
1330 		return ret;
1331 	}
1332 	reg32 &= ~GENMASK(1, 0);
1333 	reg32 |= CDNS_DP_NUM_LANES(mhdp->link.num_lanes);
1334 	reg32 |= CDNS_DP_WR_FAILING_EDGE_VSYNC;
1335 	reg32 |= CDNS_DP_FRAMER_EN;
1336 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, reg32);
1337 
1338 	/* Reset PHY config */
1339 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
1340 	if (!mhdp->host.scrambler)
1341 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
1342 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
1343 
1344 	return 0;
1345 err:
1346 	/* Reset PHY config */
1347 	reg32 = CDNS_PHY_COMMON_CONFIG | CDNS_PHY_TRAINING_TYPE(1);
1348 	if (!mhdp->host.scrambler)
1349 		reg32 |= CDNS_PHY_SCRAMBLER_BYPASS;
1350 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_PHY_CONFIG, reg32);
1351 
1352 	drm_dp_dpcd_writeb(&mhdp->aux, DP_TRAINING_PATTERN_SET,
1353 			   DP_TRAINING_PATTERN_DISABLE);
1354 
1355 	return -EIO;
1356 }
1357 
1358 static u32 cdns_mhdp_get_training_interval_us(struct cdns_mhdp_device *mhdp,
1359 					      u32 interval)
1360 {
1361 	if (interval == 0)
1362 		return 400;
1363 	if (interval < 5)
1364 		return 4000 << (interval - 1);
1365 	dev_err(mhdp->dev,
1366 		"wrong training interval returned by DPCD: %d\n", interval);
1367 	return 0;
1368 }
1369 
1370 static void cdns_mhdp_fill_host_caps(struct cdns_mhdp_device *mhdp)
1371 {
1372 	unsigned int link_rate;
1373 
1374 	/* Get source capabilities based on PHY attributes */
1375 
1376 	mhdp->host.lanes_cnt = mhdp->phy->attrs.bus_width;
1377 	if (!mhdp->host.lanes_cnt)
1378 		mhdp->host.lanes_cnt = 4;
1379 
1380 	link_rate = mhdp->phy->attrs.max_link_rate;
1381 	if (!link_rate)
1382 		link_rate = drm_dp_bw_code_to_link_rate(DP_LINK_BW_8_1);
1383 	else
1384 		/* PHY uses Mb/s, DRM uses tens of kb/s. */
1385 		link_rate *= 100;
1386 
1387 	mhdp->host.link_rate = link_rate;
1388 	mhdp->host.volt_swing = CDNS_VOLT_SWING(3);
1389 	mhdp->host.pre_emphasis = CDNS_PRE_EMPHASIS(3);
1390 	mhdp->host.pattern_supp = CDNS_SUPPORT_TPS(1) |
1391 				  CDNS_SUPPORT_TPS(2) | CDNS_SUPPORT_TPS(3) |
1392 				  CDNS_SUPPORT_TPS(4);
1393 	mhdp->host.lane_mapping = CDNS_LANE_MAPPING_NORMAL;
1394 	mhdp->host.fast_link = false;
1395 	mhdp->host.enhanced = true;
1396 	mhdp->host.scrambler = true;
1397 	mhdp->host.ssc = false;
1398 }
1399 
1400 static void cdns_mhdp_fill_sink_caps(struct cdns_mhdp_device *mhdp,
1401 				     u8 dpcd[DP_RECEIVER_CAP_SIZE])
1402 {
1403 	mhdp->sink.link_rate = mhdp->link.rate;
1404 	mhdp->sink.lanes_cnt = mhdp->link.num_lanes;
1405 	mhdp->sink.enhanced = !!(mhdp->link.capabilities &
1406 				 DP_LINK_CAP_ENHANCED_FRAMING);
1407 
1408 	/* Set SSC support */
1409 	mhdp->sink.ssc = !!(dpcd[DP_MAX_DOWNSPREAD] &
1410 				  DP_MAX_DOWNSPREAD_0_5);
1411 
1412 	/* Set TPS support */
1413 	mhdp->sink.pattern_supp = CDNS_SUPPORT_TPS(1) | CDNS_SUPPORT_TPS(2);
1414 	if (drm_dp_tps3_supported(dpcd))
1415 		mhdp->sink.pattern_supp |= CDNS_SUPPORT_TPS(3);
1416 	if (drm_dp_tps4_supported(dpcd))
1417 		mhdp->sink.pattern_supp |= CDNS_SUPPORT_TPS(4);
1418 
1419 	/* Set fast link support */
1420 	mhdp->sink.fast_link = !!(dpcd[DP_MAX_DOWNSPREAD] &
1421 				  DP_NO_AUX_HANDSHAKE_LINK_TRAINING);
1422 }
1423 
1424 static int cdns_mhdp_link_up(struct cdns_mhdp_device *mhdp)
1425 {
1426 	u8 dpcd[DP_RECEIVER_CAP_SIZE], amp[2];
1427 	u32 resp, interval, interval_us;
1428 	u8 ext_cap_chk = 0;
1429 	unsigned int addr;
1430 	int err;
1431 
1432 	WARN_ON(!mutex_is_locked(&mhdp->link_mutex));
1433 
1434 	drm_dp_dpcd_readb(&mhdp->aux, DP_TRAINING_AUX_RD_INTERVAL,
1435 			  &ext_cap_chk);
1436 
1437 	if (ext_cap_chk & DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)
1438 		addr = DP_DP13_DPCD_REV;
1439 	else
1440 		addr = DP_DPCD_REV;
1441 
1442 	err = drm_dp_dpcd_read(&mhdp->aux, addr, dpcd, DP_RECEIVER_CAP_SIZE);
1443 	if (err < 0) {
1444 		dev_err(mhdp->dev, "Failed to read receiver capabilities\n");
1445 		return err;
1446 	}
1447 
1448 	mhdp->link.revision = dpcd[0];
1449 	mhdp->link.rate = drm_dp_bw_code_to_link_rate(dpcd[1]);
1450 	mhdp->link.num_lanes = dpcd[2] & DP_MAX_LANE_COUNT_MASK;
1451 
1452 	if (dpcd[2] & DP_ENHANCED_FRAME_CAP)
1453 		mhdp->link.capabilities |= DP_LINK_CAP_ENHANCED_FRAMING;
1454 
1455 	dev_dbg(mhdp->dev, "Set sink device power state via DPCD\n");
1456 	cdns_mhdp_link_power_up(&mhdp->aux, &mhdp->link);
1457 
1458 	cdns_mhdp_fill_sink_caps(mhdp, dpcd);
1459 
1460 	mhdp->link.rate = cdns_mhdp_max_link_rate(mhdp);
1461 	mhdp->link.num_lanes = cdns_mhdp_max_num_lanes(mhdp);
1462 
1463 	/* Disable framer for link training */
1464 	err = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
1465 	if (err < 0) {
1466 		dev_err(mhdp->dev,
1467 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
1468 			err);
1469 		return err;
1470 	}
1471 
1472 	resp &= ~CDNS_DP_FRAMER_EN;
1473 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
1474 
1475 	/* Spread AMP if required, enable 8b/10b coding */
1476 	amp[0] = cdns_mhdp_get_ssc_supported(mhdp) ? DP_SPREAD_AMP_0_5 : 0;
1477 	amp[1] = DP_SET_ANSI_8B10B;
1478 	drm_dp_dpcd_write(&mhdp->aux, DP_DOWNSPREAD_CTRL, amp, 2);
1479 
1480 	if (mhdp->host.fast_link & mhdp->sink.fast_link) {
1481 		dev_err(mhdp->dev, "fastlink not supported\n");
1482 		return -EOPNOTSUPP;
1483 	}
1484 
1485 	interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & DP_TRAINING_AUX_RD_MASK;
1486 	interval_us = cdns_mhdp_get_training_interval_us(mhdp, interval);
1487 	if (!interval_us ||
1488 	    cdns_mhdp_link_training(mhdp, interval_us)) {
1489 		dev_err(mhdp->dev, "Link training failed. Exiting.\n");
1490 		return -EIO;
1491 	}
1492 
1493 	mhdp->link_up = true;
1494 
1495 	return 0;
1496 }
1497 
1498 static void cdns_mhdp_link_down(struct cdns_mhdp_device *mhdp)
1499 {
1500 	WARN_ON(!mutex_is_locked(&mhdp->link_mutex));
1501 
1502 	if (mhdp->plugged)
1503 		cdns_mhdp_link_power_down(&mhdp->aux, &mhdp->link);
1504 
1505 	mhdp->link_up = false;
1506 }
1507 
1508 static const struct drm_edid *cdns_mhdp_edid_read(struct cdns_mhdp_device *mhdp,
1509 						  struct drm_connector *connector)
1510 {
1511 	if (!mhdp->plugged)
1512 		return NULL;
1513 
1514 	return drm_edid_read_custom(connector, cdns_mhdp_get_edid_block, mhdp);
1515 }
1516 
1517 static int cdns_mhdp_get_modes(struct drm_connector *connector)
1518 {
1519 	struct cdns_mhdp_device *mhdp = connector_to_mhdp(connector);
1520 	const struct drm_edid *drm_edid;
1521 	int num_modes;
1522 
1523 	if (!mhdp->plugged)
1524 		return 0;
1525 
1526 	drm_edid = cdns_mhdp_edid_read(mhdp, connector);
1527 
1528 	drm_edid_connector_update(connector, drm_edid);
1529 
1530 	if (!drm_edid) {
1531 		dev_err(mhdp->dev, "Failed to read EDID\n");
1532 		return 0;
1533 	}
1534 
1535 	num_modes = drm_edid_connector_add_modes(connector);
1536 	drm_edid_free(drm_edid);
1537 
1538 	/*
1539 	 * HACK: Warn about unsupported display formats until we deal
1540 	 *       with them correctly.
1541 	 */
1542 	if (connector->display_info.color_formats &&
1543 	    !(connector->display_info.color_formats &
1544 	      mhdp->display_fmt.color_format))
1545 		dev_warn(mhdp->dev,
1546 			 "%s: No supported color_format found (0x%08x)\n",
1547 			__func__, connector->display_info.color_formats);
1548 
1549 	if (connector->display_info.bpc &&
1550 	    connector->display_info.bpc < mhdp->display_fmt.bpc)
1551 		dev_warn(mhdp->dev, "%s: Display bpc only %d < %d\n",
1552 			 __func__, connector->display_info.bpc,
1553 			 mhdp->display_fmt.bpc);
1554 
1555 	return num_modes;
1556 }
1557 
1558 static int cdns_mhdp_connector_detect(struct drm_connector *conn,
1559 				      struct drm_modeset_acquire_ctx *ctx,
1560 				      bool force)
1561 {
1562 	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
1563 
1564 	return cdns_mhdp_detect(mhdp);
1565 }
1566 
1567 static u32 cdns_mhdp_get_bpp(struct cdns_mhdp_display_fmt *fmt)
1568 {
1569 	u32 bpp;
1570 
1571 	if (fmt->y_only)
1572 		return fmt->bpc;
1573 
1574 	switch (fmt->color_format) {
1575 	case DRM_COLOR_FORMAT_RGB444:
1576 	case DRM_COLOR_FORMAT_YCBCR444:
1577 		bpp = fmt->bpc * 3;
1578 		break;
1579 	case DRM_COLOR_FORMAT_YCBCR422:
1580 		bpp = fmt->bpc * 2;
1581 		break;
1582 	case DRM_COLOR_FORMAT_YCBCR420:
1583 		bpp = fmt->bpc * 3 / 2;
1584 		break;
1585 	default:
1586 		bpp = fmt->bpc * 3;
1587 		WARN_ON(1);
1588 	}
1589 	return bpp;
1590 }
1591 
1592 static
1593 bool cdns_mhdp_bandwidth_ok(struct cdns_mhdp_device *mhdp,
1594 			    const struct drm_display_mode *mode,
1595 			    unsigned int lanes, unsigned int rate)
1596 {
1597 	u32 max_bw, req_bw, bpp;
1598 
1599 	/*
1600 	 * mode->clock is expressed in kHz. Multiplying by bpp and dividing by 8
1601 	 * we get the number of kB/s. DisplayPort applies a 8b-10b encoding, the
1602 	 * value thus equals the bandwidth in 10kb/s units, which matches the
1603 	 * units of the rate parameter.
1604 	 */
1605 
1606 	bpp = cdns_mhdp_get_bpp(&mhdp->display_fmt);
1607 	req_bw = mode->clock * bpp / 8;
1608 	max_bw = lanes * rate;
1609 	if (req_bw > max_bw) {
1610 		dev_dbg(mhdp->dev,
1611 			"Unsupported Mode: %s, Req BW: %u, Available Max BW:%u\n",
1612 			mode->name, req_bw, max_bw);
1613 
1614 		return false;
1615 	}
1616 
1617 	return true;
1618 }
1619 
1620 static
1621 enum drm_mode_status cdns_mhdp_mode_valid(struct drm_connector *conn,
1622 					  struct drm_display_mode *mode)
1623 {
1624 	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
1625 
1626 	mutex_lock(&mhdp->link_mutex);
1627 
1628 	if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
1629 				    mhdp->link.rate)) {
1630 		mutex_unlock(&mhdp->link_mutex);
1631 		return MODE_CLOCK_HIGH;
1632 	}
1633 
1634 	mutex_unlock(&mhdp->link_mutex);
1635 	return MODE_OK;
1636 }
1637 
1638 static int cdns_mhdp_connector_atomic_check(struct drm_connector *conn,
1639 					    struct drm_atomic_state *state)
1640 {
1641 	struct cdns_mhdp_device *mhdp = connector_to_mhdp(conn);
1642 	struct drm_connector_state *old_state, *new_state;
1643 	struct drm_crtc_state *crtc_state;
1644 	u64 old_cp, new_cp;
1645 
1646 	if (!mhdp->hdcp_supported)
1647 		return 0;
1648 
1649 	old_state = drm_atomic_get_old_connector_state(state, conn);
1650 	new_state = drm_atomic_get_new_connector_state(state, conn);
1651 	old_cp = old_state->content_protection;
1652 	new_cp = new_state->content_protection;
1653 
1654 	if (old_state->hdcp_content_type != new_state->hdcp_content_type &&
1655 	    new_cp != DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
1656 		new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
1657 		goto mode_changed;
1658 	}
1659 
1660 	if (!new_state->crtc) {
1661 		if (old_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED)
1662 			new_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
1663 		return 0;
1664 	}
1665 
1666 	if (old_cp == new_cp ||
1667 	    (old_cp == DRM_MODE_CONTENT_PROTECTION_DESIRED &&
1668 	     new_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED))
1669 		return 0;
1670 
1671 mode_changed:
1672 	crtc_state = drm_atomic_get_new_crtc_state(state, new_state->crtc);
1673 	crtc_state->mode_changed = true;
1674 
1675 	return 0;
1676 }
1677 
1678 static const struct drm_connector_helper_funcs cdns_mhdp_conn_helper_funcs = {
1679 	.detect_ctx = cdns_mhdp_connector_detect,
1680 	.get_modes = cdns_mhdp_get_modes,
1681 	.mode_valid = cdns_mhdp_mode_valid,
1682 	.atomic_check = cdns_mhdp_connector_atomic_check,
1683 };
1684 
1685 static const struct drm_connector_funcs cdns_mhdp_conn_funcs = {
1686 	.fill_modes = drm_helper_probe_single_connector_modes,
1687 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
1688 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
1689 	.reset = drm_atomic_helper_connector_reset,
1690 	.destroy = drm_connector_cleanup,
1691 };
1692 
1693 static int cdns_mhdp_connector_init(struct cdns_mhdp_device *mhdp)
1694 {
1695 	u32 bus_format = MEDIA_BUS_FMT_RGB121212_1X36;
1696 	struct drm_connector *conn = &mhdp->connector;
1697 	struct drm_bridge *bridge = &mhdp->bridge;
1698 	int ret;
1699 
1700 	conn->polled = DRM_CONNECTOR_POLL_HPD;
1701 
1702 	ret = drm_connector_init(bridge->dev, conn, &cdns_mhdp_conn_funcs,
1703 				 DRM_MODE_CONNECTOR_DisplayPort);
1704 	if (ret) {
1705 		dev_err(mhdp->dev, "Failed to initialize connector with drm\n");
1706 		return ret;
1707 	}
1708 
1709 	drm_connector_helper_add(conn, &cdns_mhdp_conn_helper_funcs);
1710 
1711 	ret = drm_display_info_set_bus_formats(&conn->display_info,
1712 					       &bus_format, 1);
1713 	if (ret)
1714 		return ret;
1715 
1716 	ret = drm_connector_attach_encoder(conn, bridge->encoder);
1717 	if (ret) {
1718 		dev_err(mhdp->dev, "Failed to attach connector to encoder\n");
1719 		return ret;
1720 	}
1721 
1722 	if (mhdp->hdcp_supported)
1723 		ret = drm_connector_attach_content_protection_property(conn, true);
1724 
1725 	return ret;
1726 }
1727 
1728 static int cdns_mhdp_attach(struct drm_bridge *bridge,
1729 			    enum drm_bridge_attach_flags flags)
1730 {
1731 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
1732 	bool hw_ready;
1733 	int ret;
1734 
1735 	dev_dbg(mhdp->dev, "%s\n", __func__);
1736 
1737 	mhdp->aux.drm_dev = bridge->dev;
1738 	ret = drm_dp_aux_register(&mhdp->aux);
1739 	if (ret < 0)
1740 		return ret;
1741 
1742 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
1743 		ret = cdns_mhdp_connector_init(mhdp);
1744 		if (ret)
1745 			goto aux_unregister;
1746 	}
1747 
1748 	spin_lock(&mhdp->start_lock);
1749 
1750 	mhdp->bridge_attached = true;
1751 	hw_ready = mhdp->hw_state == MHDP_HW_READY;
1752 
1753 	spin_unlock(&mhdp->start_lock);
1754 
1755 	/* Enable SW event interrupts */
1756 	if (hw_ready)
1757 		cdns_mhdp_bridge_hpd_enable(bridge);
1758 
1759 	return 0;
1760 aux_unregister:
1761 	drm_dp_aux_unregister(&mhdp->aux);
1762 	return ret;
1763 }
1764 
1765 static void cdns_mhdp_configure_video(struct cdns_mhdp_device *mhdp,
1766 				      const struct drm_display_mode *mode)
1767 {
1768 	unsigned int dp_framer_sp = 0, msa_horizontal_1,
1769 		msa_vertical_1, bnd_hsync2vsync, hsync2vsync_pol_ctrl,
1770 		misc0 = 0, misc1 = 0, pxl_repr,
1771 		front_porch, back_porch, msa_h0, msa_v0, hsync, vsync,
1772 		dp_vertical_1;
1773 	u8 stream_id = mhdp->stream_id;
1774 	u32 bpp, bpc, pxlfmt, framer;
1775 	int ret;
1776 
1777 	pxlfmt = mhdp->display_fmt.color_format;
1778 	bpc = mhdp->display_fmt.bpc;
1779 
1780 	/*
1781 	 * If YCBCR supported and stream not SD, use ITU709
1782 	 * Need to handle ITU version with YCBCR420 when supported
1783 	 */
1784 	if ((pxlfmt == DRM_COLOR_FORMAT_YCBCR444 ||
1785 	     pxlfmt == DRM_COLOR_FORMAT_YCBCR422) && mode->crtc_vdisplay >= 720)
1786 		misc0 = DP_YCBCR_COEFFICIENTS_ITU709;
1787 
1788 	bpp = cdns_mhdp_get_bpp(&mhdp->display_fmt);
1789 
1790 	switch (pxlfmt) {
1791 	case DRM_COLOR_FORMAT_RGB444:
1792 		pxl_repr = CDNS_DP_FRAMER_RGB << CDNS_DP_FRAMER_PXL_FORMAT;
1793 		misc0 |= DP_COLOR_FORMAT_RGB;
1794 		break;
1795 	case DRM_COLOR_FORMAT_YCBCR444:
1796 		pxl_repr = CDNS_DP_FRAMER_YCBCR444 << CDNS_DP_FRAMER_PXL_FORMAT;
1797 		misc0 |= DP_COLOR_FORMAT_YCbCr444 | DP_TEST_DYNAMIC_RANGE_CEA;
1798 		break;
1799 	case DRM_COLOR_FORMAT_YCBCR422:
1800 		pxl_repr = CDNS_DP_FRAMER_YCBCR422 << CDNS_DP_FRAMER_PXL_FORMAT;
1801 		misc0 |= DP_COLOR_FORMAT_YCbCr422 | DP_TEST_DYNAMIC_RANGE_CEA;
1802 		break;
1803 	case DRM_COLOR_FORMAT_YCBCR420:
1804 		pxl_repr = CDNS_DP_FRAMER_YCBCR420 << CDNS_DP_FRAMER_PXL_FORMAT;
1805 		break;
1806 	default:
1807 		pxl_repr = CDNS_DP_FRAMER_Y_ONLY << CDNS_DP_FRAMER_PXL_FORMAT;
1808 	}
1809 
1810 	switch (bpc) {
1811 	case 6:
1812 		misc0 |= DP_TEST_BIT_DEPTH_6;
1813 		pxl_repr |= CDNS_DP_FRAMER_6_BPC;
1814 		break;
1815 	case 8:
1816 		misc0 |= DP_TEST_BIT_DEPTH_8;
1817 		pxl_repr |= CDNS_DP_FRAMER_8_BPC;
1818 		break;
1819 	case 10:
1820 		misc0 |= DP_TEST_BIT_DEPTH_10;
1821 		pxl_repr |= CDNS_DP_FRAMER_10_BPC;
1822 		break;
1823 	case 12:
1824 		misc0 |= DP_TEST_BIT_DEPTH_12;
1825 		pxl_repr |= CDNS_DP_FRAMER_12_BPC;
1826 		break;
1827 	case 16:
1828 		misc0 |= DP_TEST_BIT_DEPTH_16;
1829 		pxl_repr |= CDNS_DP_FRAMER_16_BPC;
1830 		break;
1831 	}
1832 
1833 	bnd_hsync2vsync = CDNS_IP_BYPASS_V_INTERFACE;
1834 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
1835 		bnd_hsync2vsync |= CDNS_IP_DET_INTERLACE_FORMAT;
1836 
1837 	cdns_mhdp_reg_write(mhdp, CDNS_BND_HSYNC2VSYNC(stream_id),
1838 			    bnd_hsync2vsync);
1839 
1840 	hsync2vsync_pol_ctrl = 0;
1841 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
1842 		hsync2vsync_pol_ctrl |= CDNS_H2V_HSYNC_POL_ACTIVE_LOW;
1843 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
1844 		hsync2vsync_pol_ctrl |= CDNS_H2V_VSYNC_POL_ACTIVE_LOW;
1845 	cdns_mhdp_reg_write(mhdp, CDNS_HSYNC2VSYNC_POL_CTRL(stream_id),
1846 			    hsync2vsync_pol_ctrl);
1847 
1848 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_PXL_REPR(stream_id), pxl_repr);
1849 
1850 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
1851 		dp_framer_sp |= CDNS_DP_FRAMER_INTERLACE;
1852 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
1853 		dp_framer_sp |= CDNS_DP_FRAMER_HSYNC_POL_LOW;
1854 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
1855 		dp_framer_sp |= CDNS_DP_FRAMER_VSYNC_POL_LOW;
1856 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_SP(stream_id), dp_framer_sp);
1857 
1858 	front_porch = mode->crtc_hsync_start - mode->crtc_hdisplay;
1859 	back_porch = mode->crtc_htotal - mode->crtc_hsync_end;
1860 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRONT_BACK_PORCH(stream_id),
1861 			    CDNS_DP_FRONT_PORCH(front_porch) |
1862 			    CDNS_DP_BACK_PORCH(back_porch));
1863 
1864 	cdns_mhdp_reg_write(mhdp, CDNS_DP_BYTE_COUNT(stream_id),
1865 			    mode->crtc_hdisplay * bpp / 8);
1866 
1867 	msa_h0 = mode->crtc_htotal - mode->crtc_hsync_start;
1868 	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_0(stream_id),
1869 			    CDNS_DP_MSAH0_H_TOTAL(mode->crtc_htotal) |
1870 			    CDNS_DP_MSAH0_HSYNC_START(msa_h0));
1871 
1872 	hsync = mode->crtc_hsync_end - mode->crtc_hsync_start;
1873 	msa_horizontal_1 = CDNS_DP_MSAH1_HSYNC_WIDTH(hsync) |
1874 			   CDNS_DP_MSAH1_HDISP_WIDTH(mode->crtc_hdisplay);
1875 	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
1876 		msa_horizontal_1 |= CDNS_DP_MSAH1_HSYNC_POL_LOW;
1877 	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_HORIZONTAL_1(stream_id),
1878 			    msa_horizontal_1);
1879 
1880 	msa_v0 = mode->crtc_vtotal - mode->crtc_vsync_start;
1881 	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_0(stream_id),
1882 			    CDNS_DP_MSAV0_V_TOTAL(mode->crtc_vtotal) |
1883 			    CDNS_DP_MSAV0_VSYNC_START(msa_v0));
1884 
1885 	vsync = mode->crtc_vsync_end - mode->crtc_vsync_start;
1886 	msa_vertical_1 = CDNS_DP_MSAV1_VSYNC_WIDTH(vsync) |
1887 			 CDNS_DP_MSAV1_VDISP_WIDTH(mode->crtc_vdisplay);
1888 	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
1889 		msa_vertical_1 |= CDNS_DP_MSAV1_VSYNC_POL_LOW;
1890 	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_VERTICAL_1(stream_id),
1891 			    msa_vertical_1);
1892 
1893 	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
1894 	    mode->crtc_vtotal % 2 == 0)
1895 		misc1 = DP_TEST_INTERLACED;
1896 	if (mhdp->display_fmt.y_only)
1897 		misc1 |= CDNS_DP_TEST_COLOR_FORMAT_RAW_Y_ONLY;
1898 	/* Use VSC SDP for Y420 */
1899 	if (pxlfmt == DRM_COLOR_FORMAT_YCBCR420)
1900 		misc1 = CDNS_DP_TEST_VSC_SDP;
1901 
1902 	cdns_mhdp_reg_write(mhdp, CDNS_DP_MSA_MISC(stream_id),
1903 			    misc0 | (misc1 << 8));
1904 
1905 	cdns_mhdp_reg_write(mhdp, CDNS_DP_HORIZONTAL(stream_id),
1906 			    CDNS_DP_H_HSYNC_WIDTH(hsync) |
1907 			    CDNS_DP_H_H_TOTAL(mode->crtc_hdisplay));
1908 
1909 	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_0(stream_id),
1910 			    CDNS_DP_V0_VHEIGHT(mode->crtc_vdisplay) |
1911 			    CDNS_DP_V0_VSTART(msa_v0));
1912 
1913 	dp_vertical_1 = CDNS_DP_V1_VTOTAL(mode->crtc_vtotal);
1914 	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
1915 	    mode->crtc_vtotal % 2 == 0)
1916 		dp_vertical_1 |= CDNS_DP_V1_VTOTAL_EVEN;
1917 
1918 	cdns_mhdp_reg_write(mhdp, CDNS_DP_VERTICAL_1(stream_id), dp_vertical_1);
1919 
1920 	cdns_mhdp_reg_write_bit(mhdp, CDNS_DP_VB_ID(stream_id), 2, 1,
1921 				(mode->flags & DRM_MODE_FLAG_INTERLACE) ?
1922 				CDNS_DP_VB_ID_INTERLACED : 0);
1923 
1924 	ret = cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &framer);
1925 	if (ret < 0) {
1926 		dev_err(mhdp->dev,
1927 			"Failed to read CDNS_DP_FRAMER_GLOBAL_CONFIG %d\n",
1928 			ret);
1929 		return;
1930 	}
1931 	framer |= CDNS_DP_FRAMER_EN;
1932 	framer &= ~CDNS_DP_NO_VIDEO_MODE;
1933 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, framer);
1934 }
1935 
1936 static void cdns_mhdp_sst_enable(struct cdns_mhdp_device *mhdp,
1937 				 const struct drm_display_mode *mode)
1938 {
1939 	u32 rate, vs, required_bandwidth, available_bandwidth;
1940 	s32 line_thresh1, line_thresh2, line_thresh = 0;
1941 	int pxlclock = mode->crtc_clock;
1942 	u32 tu_size = 64;
1943 	u32 bpp;
1944 
1945 	/* Get rate in MSymbols per second per lane */
1946 	rate = mhdp->link.rate / 1000;
1947 
1948 	bpp = cdns_mhdp_get_bpp(&mhdp->display_fmt);
1949 
1950 	required_bandwidth = pxlclock * bpp / 8;
1951 	available_bandwidth = mhdp->link.num_lanes * rate;
1952 
1953 	vs = tu_size * required_bandwidth / available_bandwidth;
1954 	vs /= 1000;
1955 
1956 	if (vs == tu_size)
1957 		vs = tu_size - 1;
1958 
1959 	line_thresh1 = ((vs + 1) << 5) * 8 / bpp;
1960 	line_thresh2 = (pxlclock << 5) / 1000 / rate * (vs + 1) - (1 << 5);
1961 	line_thresh = line_thresh1 - line_thresh2 / (s32)mhdp->link.num_lanes;
1962 	line_thresh = (line_thresh >> 5) + 2;
1963 
1964 	mhdp->stream_id = 0;
1965 
1966 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_TU,
1967 			    CDNS_DP_FRAMER_TU_VS(vs) |
1968 			    CDNS_DP_FRAMER_TU_SIZE(tu_size) |
1969 			    CDNS_DP_FRAMER_TU_CNT_RST_EN);
1970 
1971 	cdns_mhdp_reg_write(mhdp, CDNS_DP_LINE_THRESH(0),
1972 			    line_thresh & GENMASK(5, 0));
1973 
1974 	cdns_mhdp_reg_write(mhdp, CDNS_DP_STREAM_CONFIG_2(0),
1975 			    CDNS_DP_SC2_TU_VS_DIFF((tu_size - vs > 3) ?
1976 						   0 : tu_size - vs));
1977 
1978 	cdns_mhdp_configure_video(mhdp, mode);
1979 }
1980 
1981 static void cdns_mhdp_atomic_enable(struct drm_bridge *bridge,
1982 				    struct drm_bridge_state *bridge_state)
1983 {
1984 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
1985 	struct drm_atomic_state *state = bridge_state->base.state;
1986 	struct cdns_mhdp_bridge_state *mhdp_state;
1987 	struct drm_crtc_state *crtc_state;
1988 	struct drm_connector *connector;
1989 	struct drm_connector_state *conn_state;
1990 	struct drm_bridge_state *new_state;
1991 	const struct drm_display_mode *mode;
1992 	u32 resp;
1993 	int ret;
1994 
1995 	dev_dbg(mhdp->dev, "bridge enable\n");
1996 
1997 	mutex_lock(&mhdp->link_mutex);
1998 
1999 	if (mhdp->plugged && !mhdp->link_up) {
2000 		ret = cdns_mhdp_link_up(mhdp);
2001 		if (ret < 0)
2002 			goto out;
2003 	}
2004 
2005 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->enable)
2006 		mhdp->info->ops->enable(mhdp);
2007 
2008 	/* Enable VIF clock for stream 0 */
2009 	ret = cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
2010 	if (ret < 0) {
2011 		dev_err(mhdp->dev, "Failed to read CDNS_DPTX_CAR %d\n", ret);
2012 		goto out;
2013 	}
2014 
2015 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
2016 			    resp | CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN);
2017 
2018 	connector = drm_atomic_get_new_connector_for_encoder(state,
2019 							     bridge->encoder);
2020 	if (WARN_ON(!connector))
2021 		goto out;
2022 
2023 	conn_state = drm_atomic_get_new_connector_state(state, connector);
2024 	if (WARN_ON(!conn_state))
2025 		goto out;
2026 
2027 	if (mhdp->hdcp_supported &&
2028 	    mhdp->hw_state == MHDP_HW_READY &&
2029 	    conn_state->content_protection ==
2030 	    DRM_MODE_CONTENT_PROTECTION_DESIRED) {
2031 		mutex_unlock(&mhdp->link_mutex);
2032 		cdns_mhdp_hdcp_enable(mhdp, conn_state->hdcp_content_type);
2033 		mutex_lock(&mhdp->link_mutex);
2034 	}
2035 
2036 	crtc_state = drm_atomic_get_new_crtc_state(state, conn_state->crtc);
2037 	if (WARN_ON(!crtc_state))
2038 		goto out;
2039 
2040 	mode = &crtc_state->adjusted_mode;
2041 
2042 	new_state = drm_atomic_get_new_bridge_state(state, bridge);
2043 	if (WARN_ON(!new_state))
2044 		goto out;
2045 
2046 	if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
2047 				    mhdp->link.rate)) {
2048 		ret = -EINVAL;
2049 		goto out;
2050 	}
2051 
2052 	cdns_mhdp_sst_enable(mhdp, mode);
2053 
2054 	mhdp_state = to_cdns_mhdp_bridge_state(new_state);
2055 
2056 	mhdp_state->current_mode = drm_mode_duplicate(bridge->dev, mode);
2057 	if (!mhdp_state->current_mode)
2058 		return;
2059 
2060 	drm_mode_set_name(mhdp_state->current_mode);
2061 
2062 	dev_dbg(mhdp->dev, "%s: Enabling mode %s\n", __func__, mode->name);
2063 
2064 	mhdp->bridge_enabled = true;
2065 
2066 out:
2067 	mutex_unlock(&mhdp->link_mutex);
2068 	if (ret < 0)
2069 		schedule_work(&mhdp->modeset_retry_work);
2070 }
2071 
2072 static void cdns_mhdp_atomic_disable(struct drm_bridge *bridge,
2073 				     struct drm_bridge_state *bridge_state)
2074 {
2075 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
2076 	u32 resp;
2077 
2078 	dev_dbg(mhdp->dev, "%s\n", __func__);
2079 
2080 	mutex_lock(&mhdp->link_mutex);
2081 
2082 	if (mhdp->hdcp_supported)
2083 		cdns_mhdp_hdcp_disable(mhdp);
2084 
2085 	mhdp->bridge_enabled = false;
2086 	cdns_mhdp_reg_read(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, &resp);
2087 	resp &= ~CDNS_DP_FRAMER_EN;
2088 	resp |= CDNS_DP_NO_VIDEO_MODE;
2089 	cdns_mhdp_reg_write(mhdp, CDNS_DP_FRAMER_GLOBAL_CONFIG, resp);
2090 
2091 	cdns_mhdp_link_down(mhdp);
2092 
2093 	/* Disable VIF clock for stream 0 */
2094 	cdns_mhdp_reg_read(mhdp, CDNS_DPTX_CAR, &resp);
2095 	cdns_mhdp_reg_write(mhdp, CDNS_DPTX_CAR,
2096 			    resp & ~(CDNS_VIF_CLK_EN | CDNS_VIF_CLK_RSTN));
2097 
2098 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->disable)
2099 		mhdp->info->ops->disable(mhdp);
2100 
2101 	mutex_unlock(&mhdp->link_mutex);
2102 }
2103 
2104 static void cdns_mhdp_detach(struct drm_bridge *bridge)
2105 {
2106 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
2107 
2108 	dev_dbg(mhdp->dev, "%s\n", __func__);
2109 
2110 	drm_dp_aux_unregister(&mhdp->aux);
2111 
2112 	spin_lock(&mhdp->start_lock);
2113 
2114 	mhdp->bridge_attached = false;
2115 
2116 	spin_unlock(&mhdp->start_lock);
2117 
2118 	writel(~0, mhdp->regs + CDNS_APB_INT_MASK);
2119 }
2120 
2121 static struct drm_bridge_state *
2122 cdns_mhdp_bridge_atomic_duplicate_state(struct drm_bridge *bridge)
2123 {
2124 	struct cdns_mhdp_bridge_state *state;
2125 
2126 	state = kzalloc(sizeof(*state), GFP_KERNEL);
2127 	if (!state)
2128 		return NULL;
2129 
2130 	__drm_atomic_helper_bridge_duplicate_state(bridge, &state->base);
2131 
2132 	return &state->base;
2133 }
2134 
2135 static void
2136 cdns_mhdp_bridge_atomic_destroy_state(struct drm_bridge *bridge,
2137 				      struct drm_bridge_state *state)
2138 {
2139 	struct cdns_mhdp_bridge_state *cdns_mhdp_state;
2140 
2141 	cdns_mhdp_state = to_cdns_mhdp_bridge_state(state);
2142 
2143 	if (cdns_mhdp_state->current_mode) {
2144 		drm_mode_destroy(bridge->dev, cdns_mhdp_state->current_mode);
2145 		cdns_mhdp_state->current_mode = NULL;
2146 	}
2147 
2148 	kfree(cdns_mhdp_state);
2149 }
2150 
2151 static struct drm_bridge_state *
2152 cdns_mhdp_bridge_atomic_reset(struct drm_bridge *bridge)
2153 {
2154 	struct cdns_mhdp_bridge_state *cdns_mhdp_state;
2155 
2156 	cdns_mhdp_state = kzalloc(sizeof(*cdns_mhdp_state), GFP_KERNEL);
2157 	if (!cdns_mhdp_state)
2158 		return NULL;
2159 
2160 	__drm_atomic_helper_bridge_reset(bridge, &cdns_mhdp_state->base);
2161 
2162 	return &cdns_mhdp_state->base;
2163 }
2164 
2165 static u32 *cdns_mhdp_get_input_bus_fmts(struct drm_bridge *bridge,
2166 					 struct drm_bridge_state *bridge_state,
2167 					 struct drm_crtc_state *crtc_state,
2168 					 struct drm_connector_state *conn_state,
2169 					 u32 output_fmt,
2170 					 unsigned int *num_input_fmts)
2171 {
2172 	u32 *input_fmts;
2173 
2174 	*num_input_fmts = 0;
2175 
2176 	input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
2177 	if (!input_fmts)
2178 		return NULL;
2179 
2180 	*num_input_fmts = 1;
2181 	input_fmts[0] = MEDIA_BUS_FMT_RGB121212_1X36;
2182 
2183 	return input_fmts;
2184 }
2185 
2186 static int cdns_mhdp_atomic_check(struct drm_bridge *bridge,
2187 				  struct drm_bridge_state *bridge_state,
2188 				  struct drm_crtc_state *crtc_state,
2189 				  struct drm_connector_state *conn_state)
2190 {
2191 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
2192 	const struct drm_display_mode *mode = &crtc_state->adjusted_mode;
2193 
2194 	mutex_lock(&mhdp->link_mutex);
2195 
2196 	if (!cdns_mhdp_bandwidth_ok(mhdp, mode, mhdp->link.num_lanes,
2197 				    mhdp->link.rate)) {
2198 		dev_err(mhdp->dev, "%s: Not enough BW for %s (%u lanes at %u Mbps)\n",
2199 			__func__, mode->name, mhdp->link.num_lanes,
2200 			mhdp->link.rate / 100);
2201 		mutex_unlock(&mhdp->link_mutex);
2202 		return -EINVAL;
2203 	}
2204 
2205 	/*
2206 	 * There might be flags negotiation supported in future.
2207 	 * Set the bus flags in atomic_check statically for now.
2208 	 */
2209 	if (mhdp->info)
2210 		bridge_state->input_bus_cfg.flags = *mhdp->info->input_bus_flags;
2211 
2212 	mutex_unlock(&mhdp->link_mutex);
2213 	return 0;
2214 }
2215 
2216 static enum drm_connector_status cdns_mhdp_bridge_detect(struct drm_bridge *bridge)
2217 {
2218 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
2219 
2220 	return cdns_mhdp_detect(mhdp);
2221 }
2222 
2223 static const struct drm_edid *cdns_mhdp_bridge_edid_read(struct drm_bridge *bridge,
2224 							 struct drm_connector *connector)
2225 {
2226 	struct cdns_mhdp_device *mhdp = bridge_to_mhdp(bridge);
2227 
2228 	return cdns_mhdp_edid_read(mhdp, connector);
2229 }
2230 
2231 static const struct drm_bridge_funcs cdns_mhdp_bridge_funcs = {
2232 	.atomic_enable = cdns_mhdp_atomic_enable,
2233 	.atomic_disable = cdns_mhdp_atomic_disable,
2234 	.atomic_check = cdns_mhdp_atomic_check,
2235 	.attach = cdns_mhdp_attach,
2236 	.detach = cdns_mhdp_detach,
2237 	.atomic_duplicate_state = cdns_mhdp_bridge_atomic_duplicate_state,
2238 	.atomic_destroy_state = cdns_mhdp_bridge_atomic_destroy_state,
2239 	.atomic_reset = cdns_mhdp_bridge_atomic_reset,
2240 	.atomic_get_input_bus_fmts = cdns_mhdp_get_input_bus_fmts,
2241 	.detect = cdns_mhdp_bridge_detect,
2242 	.edid_read = cdns_mhdp_bridge_edid_read,
2243 	.hpd_enable = cdns_mhdp_bridge_hpd_enable,
2244 	.hpd_disable = cdns_mhdp_bridge_hpd_disable,
2245 };
2246 
2247 static bool cdns_mhdp_detect_hpd(struct cdns_mhdp_device *mhdp, bool *hpd_pulse)
2248 {
2249 	int hpd_event, hpd_status;
2250 
2251 	*hpd_pulse = false;
2252 
2253 	hpd_event = cdns_mhdp_read_hpd_event(mhdp);
2254 
2255 	/* Getting event bits failed, bail out */
2256 	if (hpd_event < 0) {
2257 		dev_warn(mhdp->dev, "%s: read event failed: %d\n",
2258 			 __func__, hpd_event);
2259 		return false;
2260 	}
2261 
2262 	hpd_status = cdns_mhdp_get_hpd_status(mhdp);
2263 	if (hpd_status < 0) {
2264 		dev_warn(mhdp->dev, "%s: get hpd status failed: %d\n",
2265 			 __func__, hpd_status);
2266 		return false;
2267 	}
2268 
2269 	if (hpd_event & DPTX_READ_EVENT_HPD_PULSE)
2270 		*hpd_pulse = true;
2271 
2272 	return !!hpd_status;
2273 }
2274 
2275 static int cdns_mhdp_update_link_status(struct cdns_mhdp_device *mhdp)
2276 {
2277 	struct cdns_mhdp_bridge_state *cdns_bridge_state;
2278 	struct drm_display_mode *current_mode;
2279 	bool old_plugged = mhdp->plugged;
2280 	struct drm_bridge_state *state;
2281 	u8 status[DP_LINK_STATUS_SIZE];
2282 	bool hpd_pulse;
2283 	int ret = 0;
2284 
2285 	mutex_lock(&mhdp->link_mutex);
2286 
2287 	mhdp->plugged = cdns_mhdp_detect_hpd(mhdp, &hpd_pulse);
2288 
2289 	if (!mhdp->plugged) {
2290 		cdns_mhdp_link_down(mhdp);
2291 		mhdp->link.rate = mhdp->host.link_rate;
2292 		mhdp->link.num_lanes = mhdp->host.lanes_cnt;
2293 		goto out;
2294 	}
2295 
2296 	/*
2297 	 * If we get a HPD pulse event and we were and still are connected,
2298 	 * check the link status. If link status is ok, there's nothing to do
2299 	 * as we don't handle DP interrupts. If link status is bad, continue
2300 	 * with full link setup.
2301 	 */
2302 	if (hpd_pulse && old_plugged == mhdp->plugged) {
2303 		ret = drm_dp_dpcd_read_link_status(&mhdp->aux, status);
2304 
2305 		/*
2306 		 * If everything looks fine, just return, as we don't handle
2307 		 * DP IRQs.
2308 		 */
2309 		if (ret > 0 &&
2310 		    drm_dp_channel_eq_ok(status, mhdp->link.num_lanes) &&
2311 		    drm_dp_clock_recovery_ok(status, mhdp->link.num_lanes))
2312 			goto out;
2313 
2314 		/* If link is bad, mark link as down so that we do a new LT */
2315 		mhdp->link_up = false;
2316 	}
2317 
2318 	if (!mhdp->link_up) {
2319 		ret = cdns_mhdp_link_up(mhdp);
2320 		if (ret < 0)
2321 			goto out;
2322 	}
2323 
2324 	if (mhdp->bridge_enabled) {
2325 		state = drm_priv_to_bridge_state(mhdp->bridge.base.state);
2326 		if (!state) {
2327 			ret = -EINVAL;
2328 			goto out;
2329 		}
2330 
2331 		cdns_bridge_state = to_cdns_mhdp_bridge_state(state);
2332 		if (!cdns_bridge_state) {
2333 			ret = -EINVAL;
2334 			goto out;
2335 		}
2336 
2337 		current_mode = cdns_bridge_state->current_mode;
2338 		if (!current_mode) {
2339 			ret = -EINVAL;
2340 			goto out;
2341 		}
2342 
2343 		if (!cdns_mhdp_bandwidth_ok(mhdp, current_mode, mhdp->link.num_lanes,
2344 					    mhdp->link.rate)) {
2345 			ret = -EINVAL;
2346 			goto out;
2347 		}
2348 
2349 		dev_dbg(mhdp->dev, "%s: Enabling mode %s\n", __func__,
2350 			current_mode->name);
2351 
2352 		cdns_mhdp_sst_enable(mhdp, current_mode);
2353 	}
2354 out:
2355 	mutex_unlock(&mhdp->link_mutex);
2356 	return ret;
2357 }
2358 
2359 static void cdns_mhdp_modeset_retry_fn(struct work_struct *work)
2360 {
2361 	struct cdns_mhdp_device *mhdp;
2362 	struct drm_connector *conn;
2363 
2364 	mhdp = container_of(work, typeof(*mhdp), modeset_retry_work);
2365 
2366 	conn = &mhdp->connector;
2367 
2368 	/* Grab the locks before changing connector property */
2369 	mutex_lock(&conn->dev->mode_config.mutex);
2370 
2371 	/*
2372 	 * Set connector link status to BAD and send a Uevent to notify
2373 	 * userspace to do a modeset.
2374 	 */
2375 	drm_connector_set_link_status_property(conn, DRM_MODE_LINK_STATUS_BAD);
2376 	mutex_unlock(&conn->dev->mode_config.mutex);
2377 
2378 	/* Send Hotplug uevent so userspace can reprobe */
2379 	drm_kms_helper_hotplug_event(mhdp->bridge.dev);
2380 }
2381 
2382 static irqreturn_t cdns_mhdp_irq_handler(int irq, void *data)
2383 {
2384 	struct cdns_mhdp_device *mhdp = data;
2385 	u32 apb_stat, sw_ev0;
2386 	bool bridge_attached;
2387 
2388 	apb_stat = readl(mhdp->regs + CDNS_APB_INT_STATUS);
2389 	if (!(apb_stat & CDNS_APB_INT_MASK_SW_EVENT_INT))
2390 		return IRQ_NONE;
2391 
2392 	sw_ev0 = readl(mhdp->regs + CDNS_SW_EVENT0);
2393 
2394 	/*
2395 	 *  Calling drm_kms_helper_hotplug_event() when not attached
2396 	 *  to drm device causes an oops because the drm_bridge->dev
2397 	 *  is NULL. See cdns_mhdp_fw_cb() comments for details about the
2398 	 *  problems related drm_kms_helper_hotplug_event() call.
2399 	 */
2400 	spin_lock(&mhdp->start_lock);
2401 	bridge_attached = mhdp->bridge_attached;
2402 	spin_unlock(&mhdp->start_lock);
2403 
2404 	if (bridge_attached && (sw_ev0 & CDNS_DPTX_HPD)) {
2405 		schedule_work(&mhdp->hpd_work);
2406 	}
2407 
2408 	if (sw_ev0 & ~CDNS_DPTX_HPD) {
2409 		mhdp->sw_events |= (sw_ev0 & ~CDNS_DPTX_HPD);
2410 		wake_up(&mhdp->sw_events_wq);
2411 	}
2412 
2413 	return IRQ_HANDLED;
2414 }
2415 
2416 u32 cdns_mhdp_wait_for_sw_event(struct cdns_mhdp_device *mhdp, u32 event)
2417 {
2418 	u32 ret;
2419 
2420 	ret = wait_event_timeout(mhdp->sw_events_wq,
2421 				 mhdp->sw_events & event,
2422 				 msecs_to_jiffies(500));
2423 	if (!ret) {
2424 		dev_dbg(mhdp->dev, "SW event 0x%x timeout\n", event);
2425 		goto sw_event_out;
2426 	}
2427 
2428 	ret = mhdp->sw_events;
2429 	mhdp->sw_events &= ~event;
2430 
2431 sw_event_out:
2432 	return ret;
2433 }
2434 
2435 static void cdns_mhdp_hpd_work(struct work_struct *work)
2436 {
2437 	struct cdns_mhdp_device *mhdp = container_of(work,
2438 						     struct cdns_mhdp_device,
2439 						     hpd_work);
2440 	int ret;
2441 
2442 	ret = cdns_mhdp_update_link_status(mhdp);
2443 	if (mhdp->connector.dev) {
2444 		if (ret < 0)
2445 			schedule_work(&mhdp->modeset_retry_work);
2446 		else
2447 			drm_kms_helper_hotplug_event(mhdp->bridge.dev);
2448 	} else {
2449 		drm_bridge_hpd_notify(&mhdp->bridge, cdns_mhdp_detect(mhdp));
2450 	}
2451 }
2452 
2453 static int cdns_mhdp_probe(struct platform_device *pdev)
2454 {
2455 	struct device *dev = &pdev->dev;
2456 	struct cdns_mhdp_device *mhdp;
2457 	unsigned long rate;
2458 	struct clk *clk;
2459 	int ret;
2460 	int irq;
2461 
2462 	mhdp = devm_kzalloc(dev, sizeof(*mhdp), GFP_KERNEL);
2463 	if (!mhdp)
2464 		return -ENOMEM;
2465 
2466 	clk = devm_clk_get(dev, NULL);
2467 	if (IS_ERR(clk)) {
2468 		dev_err(dev, "couldn't get clk: %ld\n", PTR_ERR(clk));
2469 		return PTR_ERR(clk);
2470 	}
2471 
2472 	mhdp->clk = clk;
2473 	mhdp->dev = dev;
2474 	mutex_init(&mhdp->mbox_mutex);
2475 	mutex_init(&mhdp->link_mutex);
2476 	spin_lock_init(&mhdp->start_lock);
2477 
2478 	drm_dp_aux_init(&mhdp->aux);
2479 	mhdp->aux.dev = dev;
2480 	mhdp->aux.transfer = cdns_mhdp_transfer;
2481 
2482 	mhdp->regs = devm_platform_ioremap_resource(pdev, 0);
2483 	if (IS_ERR(mhdp->regs)) {
2484 		dev_err(dev, "Failed to get memory resource\n");
2485 		return PTR_ERR(mhdp->regs);
2486 	}
2487 
2488 	mhdp->sapb_regs = devm_platform_ioremap_resource_byname(pdev, "mhdptx-sapb");
2489 	if (IS_ERR(mhdp->sapb_regs)) {
2490 		mhdp->hdcp_supported = false;
2491 		dev_warn(dev,
2492 			 "Failed to get SAPB memory resource, HDCP not supported\n");
2493 	} else {
2494 		mhdp->hdcp_supported = true;
2495 	}
2496 
2497 	mhdp->phy = devm_of_phy_get_by_index(dev, pdev->dev.of_node, 0);
2498 	if (IS_ERR(mhdp->phy)) {
2499 		dev_err(dev, "no PHY configured\n");
2500 		return PTR_ERR(mhdp->phy);
2501 	}
2502 
2503 	platform_set_drvdata(pdev, mhdp);
2504 
2505 	mhdp->info = of_device_get_match_data(dev);
2506 
2507 	clk_prepare_enable(clk);
2508 
2509 	pm_runtime_enable(dev);
2510 	ret = pm_runtime_resume_and_get(dev);
2511 	if (ret < 0) {
2512 		dev_err(dev, "pm_runtime_resume_and_get failed\n");
2513 		pm_runtime_disable(dev);
2514 		goto clk_disable;
2515 	}
2516 
2517 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->init) {
2518 		ret = mhdp->info->ops->init(mhdp);
2519 		if (ret != 0) {
2520 			dev_err(dev, "MHDP platform initialization failed: %d\n",
2521 				ret);
2522 			goto runtime_put;
2523 		}
2524 	}
2525 
2526 	rate = clk_get_rate(clk);
2527 	writel(rate % 1000000, mhdp->regs + CDNS_SW_CLK_L);
2528 	writel(rate / 1000000, mhdp->regs + CDNS_SW_CLK_H);
2529 
2530 	dev_dbg(dev, "func clk rate %lu Hz\n", rate);
2531 
2532 	writel(~0, mhdp->regs + CDNS_APB_INT_MASK);
2533 
2534 	irq = platform_get_irq(pdev, 0);
2535 	ret = devm_request_threaded_irq(mhdp->dev, irq, NULL,
2536 					cdns_mhdp_irq_handler, IRQF_ONESHOT,
2537 					"mhdp8546", mhdp);
2538 	if (ret) {
2539 		dev_err(dev, "cannot install IRQ %d\n", irq);
2540 		ret = -EIO;
2541 		goto plat_fini;
2542 	}
2543 
2544 	cdns_mhdp_fill_host_caps(mhdp);
2545 
2546 	/* Initialize link rate and num of lanes to host values */
2547 	mhdp->link.rate = mhdp->host.link_rate;
2548 	mhdp->link.num_lanes = mhdp->host.lanes_cnt;
2549 
2550 	/* The only currently supported format */
2551 	mhdp->display_fmt.y_only = false;
2552 	mhdp->display_fmt.color_format = DRM_COLOR_FORMAT_RGB444;
2553 	mhdp->display_fmt.bpc = 8;
2554 
2555 	mhdp->bridge.of_node = pdev->dev.of_node;
2556 	mhdp->bridge.funcs = &cdns_mhdp_bridge_funcs;
2557 	mhdp->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID |
2558 			   DRM_BRIDGE_OP_HPD;
2559 	mhdp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
2560 
2561 	ret = phy_init(mhdp->phy);
2562 	if (ret) {
2563 		dev_err(mhdp->dev, "Failed to initialize PHY: %d\n", ret);
2564 		goto plat_fini;
2565 	}
2566 
2567 	/* Initialize the work for modeset in case of link train failure */
2568 	INIT_WORK(&mhdp->modeset_retry_work, cdns_mhdp_modeset_retry_fn);
2569 	INIT_WORK(&mhdp->hpd_work, cdns_mhdp_hpd_work);
2570 
2571 	init_waitqueue_head(&mhdp->fw_load_wq);
2572 	init_waitqueue_head(&mhdp->sw_events_wq);
2573 
2574 	ret = cdns_mhdp_load_firmware(mhdp);
2575 	if (ret)
2576 		goto phy_exit;
2577 
2578 	if (mhdp->hdcp_supported)
2579 		cdns_mhdp_hdcp_init(mhdp);
2580 
2581 	drm_bridge_add(&mhdp->bridge);
2582 
2583 	return 0;
2584 
2585 phy_exit:
2586 	phy_exit(mhdp->phy);
2587 plat_fini:
2588 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->exit)
2589 		mhdp->info->ops->exit(mhdp);
2590 runtime_put:
2591 	pm_runtime_put_sync(dev);
2592 	pm_runtime_disable(dev);
2593 clk_disable:
2594 	clk_disable_unprepare(mhdp->clk);
2595 
2596 	return ret;
2597 }
2598 
2599 static void cdns_mhdp_remove(struct platform_device *pdev)
2600 {
2601 	struct cdns_mhdp_device *mhdp = platform_get_drvdata(pdev);
2602 	unsigned long timeout = msecs_to_jiffies(100);
2603 	int ret;
2604 
2605 	drm_bridge_remove(&mhdp->bridge);
2606 
2607 	ret = wait_event_timeout(mhdp->fw_load_wq,
2608 				 mhdp->hw_state == MHDP_HW_READY,
2609 				 timeout);
2610 	spin_lock(&mhdp->start_lock);
2611 	mhdp->hw_state = MHDP_HW_STOPPED;
2612 	spin_unlock(&mhdp->start_lock);
2613 
2614 	if (ret == 0) {
2615 		dev_err(mhdp->dev, "%s: Timeout waiting for fw loading\n",
2616 			__func__);
2617 	} else {
2618 		ret = cdns_mhdp_set_firmware_active(mhdp, false);
2619 		if (ret)
2620 			dev_err(mhdp->dev, "Failed to stop firmware (%pe)\n",
2621 				ERR_PTR(ret));
2622 	}
2623 
2624 	phy_exit(mhdp->phy);
2625 
2626 	if (mhdp->info && mhdp->info->ops && mhdp->info->ops->exit)
2627 		mhdp->info->ops->exit(mhdp);
2628 
2629 	pm_runtime_put_sync(&pdev->dev);
2630 	pm_runtime_disable(&pdev->dev);
2631 
2632 	cancel_work_sync(&mhdp->modeset_retry_work);
2633 	flush_work(&mhdp->hpd_work);
2634 	/* Ignoring mhdp->hdcp.check_work and mhdp->hdcp.prop_work here. */
2635 
2636 	clk_disable_unprepare(mhdp->clk);
2637 }
2638 
2639 static const struct of_device_id mhdp_ids[] = {
2640 	{ .compatible = "cdns,mhdp8546", },
2641 #ifdef CONFIG_DRM_CDNS_MHDP8546_J721E
2642 	{ .compatible = "ti,j721e-mhdp8546",
2643 	  .data = &(const struct cdns_mhdp_platform_info) {
2644 		  .input_bus_flags = &mhdp_ti_j721e_bridge_input_bus_flags,
2645 		  .ops = &mhdp_ti_j721e_ops,
2646 	  },
2647 	},
2648 #endif
2649 	{ /* sentinel */ }
2650 };
2651 MODULE_DEVICE_TABLE(of, mhdp_ids);
2652 
2653 static struct platform_driver mhdp_driver = {
2654 	.driver	= {
2655 		.name		= "cdns-mhdp8546",
2656 		.of_match_table	= mhdp_ids,
2657 	},
2658 	.probe	= cdns_mhdp_probe,
2659 	.remove_new = cdns_mhdp_remove,
2660 };
2661 module_platform_driver(mhdp_driver);
2662 
2663 MODULE_FIRMWARE(FW_NAME);
2664 
2665 MODULE_AUTHOR("Quentin Schulz <quentin.schulz@free-electrons.com>");
2666 MODULE_AUTHOR("Swapnil Jakhade <sjakhade@cadence.com>");
2667 MODULE_AUTHOR("Yuti Amonkar <yamonkar@cadence.com>");
2668 MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
2669 MODULE_AUTHOR("Jyri Sarha <jsarha@ti.com>");
2670 MODULE_DESCRIPTION("Cadence MHDP8546 DP bridge driver");
2671 MODULE_LICENSE("GPL");
2672 MODULE_ALIAS("platform:cdns-mhdp8546");
2673