xref: /openbmc/linux/drivers/thunderbolt/lc.c (revision 30a4eca6)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Thunderbolt link controller support
4  *
5  * Copyright (C) 2019, Intel Corporation
6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
7  */
8 
9 #include "tb.h"
10 
11 /**
12  * tb_lc_read_uuid() - Read switch UUID from link controller common register
13  * @sw: Switch whose UUID is read
14  * @uuid: UUID is placed here
15  */
16 int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid)
17 {
18 	if (!sw->cap_lc)
19 		return -EINVAL;
20 	return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4);
21 }
22 
23 static int read_lc_desc(struct tb_switch *sw, u32 *desc)
24 {
25 	if (!sw->cap_lc)
26 		return -EINVAL;
27 	return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1);
28 }
29 
30 static int find_port_lc_cap(struct tb_port *port)
31 {
32 	struct tb_switch *sw = port->sw;
33 	int start, phys, ret, size;
34 	u32 desc;
35 
36 	ret = read_lc_desc(sw, &desc);
37 	if (ret)
38 		return ret;
39 
40 	/* Start of port LC registers */
41 	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
42 	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
43 	phys = tb_phy_port_from_link(port->port);
44 
45 	return sw->cap_lc + start + phys * size;
46 }
47 
48 static int tb_lc_set_port_configured(struct tb_port *port, bool configured)
49 {
50 	bool upstream = tb_is_upstream_port(port);
51 	struct tb_switch *sw = port->sw;
52 	u32 ctrl, lane;
53 	int cap, ret;
54 
55 	if (sw->generation < 2)
56 		return 0;
57 
58 	cap = find_port_lc_cap(port);
59 	if (cap < 0)
60 		return cap;
61 
62 	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
63 	if (ret)
64 		return ret;
65 
66 	/* Resolve correct lane */
67 	if (port->port % 2)
68 		lane = TB_LC_SX_CTRL_L1C;
69 	else
70 		lane = TB_LC_SX_CTRL_L2C;
71 
72 	if (configured) {
73 		ctrl |= lane;
74 		if (upstream)
75 			ctrl |= TB_LC_SX_CTRL_UPSTREAM;
76 	} else {
77 		ctrl &= ~lane;
78 		if (upstream)
79 			ctrl &= ~TB_LC_SX_CTRL_UPSTREAM;
80 	}
81 
82 	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
83 }
84 
85 /**
86  * tb_lc_configure_port() - Let LC know about configured port
87  * @port: Port that is set as configured
88  *
89  * Sets the port configured for power management purposes.
90  */
91 int tb_lc_configure_port(struct tb_port *port)
92 {
93 	return tb_lc_set_port_configured(port, true);
94 }
95 
96 /**
97  * tb_lc_unconfigure_port() - Let LC know about unconfigured port
98  * @port: Port that is set as configured
99  *
100  * Sets the port unconfigured for power management purposes.
101  */
102 void tb_lc_unconfigure_port(struct tb_port *port)
103 {
104 	tb_lc_set_port_configured(port, false);
105 }
106 
107 static int tb_lc_set_xdomain_configured(struct tb_port *port, bool configure)
108 {
109 	struct tb_switch *sw = port->sw;
110 	u32 ctrl, lane;
111 	int cap, ret;
112 
113 	if (sw->generation < 2)
114 		return 0;
115 
116 	cap = find_port_lc_cap(port);
117 	if (cap < 0)
118 		return cap;
119 
120 	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
121 	if (ret)
122 		return ret;
123 
124 	/* Resolve correct lane */
125 	if (port->port % 2)
126 		lane = TB_LC_SX_CTRL_L1D;
127 	else
128 		lane = TB_LC_SX_CTRL_L2D;
129 
130 	if (configure)
131 		ctrl |= lane;
132 	else
133 		ctrl &= ~lane;
134 
135 	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
136 }
137 
138 /**
139  * tb_lc_configure_xdomain() - Inform LC that the link is XDomain
140  * @port: Switch downstream port connected to another host
141  *
142  * Sets the lane configured for XDomain accordingly so that the LC knows
143  * about this. Returns %0 in success and negative errno in failure.
144  */
145 int tb_lc_configure_xdomain(struct tb_port *port)
146 {
147 	return tb_lc_set_xdomain_configured(port, true);
148 }
149 
150 /**
151  * tb_lc_unconfigure_xdomain() - Unconfigure XDomain from port
152  * @port: Switch downstream port that was connected to another host
153  *
154  * Unsets the lane XDomain configuration.
155  */
156 void tb_lc_unconfigure_xdomain(struct tb_port *port)
157 {
158 	tb_lc_set_xdomain_configured(port, false);
159 }
160 
161 /**
162  * tb_lc_start_lane_initialization() - Start lane initialization
163  * @port: Device router lane 0 adapter
164  *
165  * Starts lane initialization for @port after the router resumed from
166  * sleep. Should be called for those downstream lane adapters that were
167  * not connected (tb_lc_configure_port() was not called) before sleep.
168  *
169  * Returns %0 in success and negative errno in case of failure.
170  */
171 int tb_lc_start_lane_initialization(struct tb_port *port)
172 {
173 	struct tb_switch *sw = port->sw;
174 	int ret, cap;
175 	u32 ctrl;
176 
177 	if (!tb_route(sw))
178 		return 0;
179 
180 	if (sw->generation < 2)
181 		return 0;
182 
183 	cap = find_port_lc_cap(port);
184 	if (cap < 0)
185 		return cap;
186 
187 	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
188 	if (ret)
189 		return ret;
190 
191 	ctrl |= TB_LC_SX_CTRL_SLI;
192 
193 	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
194 }
195 
196 /**
197  * tb_lc_is_clx_supported() - Check whether CLx is supported by the lane adapter
198  * @port: Lane adapter
199  *
200  * TB_LC_LINK_ATTR_CPS bit reflects if the link supports CLx including
201  * active cables (if connected on the link).
202  */
203 bool tb_lc_is_clx_supported(struct tb_port *port)
204 {
205 	struct tb_switch *sw = port->sw;
206 	int cap, ret;
207 	u32 val;
208 
209 	cap = find_port_lc_cap(port);
210 	if (cap < 0)
211 		return false;
212 
213 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_LINK_ATTR, 1);
214 	if (ret)
215 		return false;
216 
217 	return !!(val & TB_LC_LINK_ATTR_CPS);
218 }
219 
220 /**
221  * tb_lc_is_usb_plugged() - Is there USB device connected to port
222  * @port: Device router lane 0 adapter
223  *
224  * Returns true if the @port has USB type-C device connected.
225  */
226 bool tb_lc_is_usb_plugged(struct tb_port *port)
227 {
228 	struct tb_switch *sw = port->sw;
229 	int cap, ret;
230 	u32 val;
231 
232 	if (sw->generation != 3)
233 		return false;
234 
235 	cap = find_port_lc_cap(port);
236 	if (cap < 0)
237 		return false;
238 
239 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_CS_42, 1);
240 	if (ret)
241 		return false;
242 
243 	return !!(val & TB_LC_CS_42_USB_PLUGGED);
244 }
245 
246 /**
247  * tb_lc_is_xhci_connected() - Is the internal xHCI connected
248  * @port: Device router lane 0 adapter
249  *
250  * Returns true if the internal xHCI has been connected to @port.
251  */
252 bool tb_lc_is_xhci_connected(struct tb_port *port)
253 {
254 	struct tb_switch *sw = port->sw;
255 	int cap, ret;
256 	u32 val;
257 
258 	if (sw->generation != 3)
259 		return false;
260 
261 	cap = find_port_lc_cap(port);
262 	if (cap < 0)
263 		return false;
264 
265 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_LINK_REQ, 1);
266 	if (ret)
267 		return false;
268 
269 	return !!(val & TB_LC_LINK_REQ_XHCI_CONNECT);
270 }
271 
272 static int __tb_lc_xhci_connect(struct tb_port *port, bool connect)
273 {
274 	struct tb_switch *sw = port->sw;
275 	int cap, ret;
276 	u32 val;
277 
278 	if (sw->generation != 3)
279 		return -EINVAL;
280 
281 	cap = find_port_lc_cap(port);
282 	if (cap < 0)
283 		return cap;
284 
285 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_LINK_REQ, 1);
286 	if (ret)
287 		return ret;
288 
289 	if (connect)
290 		val |= TB_LC_LINK_REQ_XHCI_CONNECT;
291 	else
292 		val &= ~TB_LC_LINK_REQ_XHCI_CONNECT;
293 
294 	return tb_sw_write(sw, &val, TB_CFG_SWITCH, cap + TB_LC_LINK_REQ, 1);
295 }
296 
297 /**
298  * tb_lc_xhci_connect() - Connect internal xHCI
299  * @port: Device router lane 0 adapter
300  *
301  * Tells LC to connect the internal xHCI to @port. Returns %0 on success
302  * and negative errno in case of failure. Can be called for Thunderbolt 3
303  * routers only.
304  */
305 int tb_lc_xhci_connect(struct tb_port *port)
306 {
307 	int ret;
308 
309 	ret = __tb_lc_xhci_connect(port, true);
310 	if (ret)
311 		return ret;
312 
313 	tb_port_dbg(port, "xHCI connected\n");
314 	return 0;
315 }
316 
317 /**
318  * tb_lc_xhci_disconnect() - Disconnect internal xHCI
319  * @port: Device router lane 0 adapter
320  *
321  * Tells LC to disconnect the internal xHCI from @port. Can be called
322  * for Thunderbolt 3 routers only.
323  */
324 void tb_lc_xhci_disconnect(struct tb_port *port)
325 {
326 	__tb_lc_xhci_connect(port, false);
327 	tb_port_dbg(port, "xHCI disconnected\n");
328 }
329 
330 static int tb_lc_set_wake_one(struct tb_switch *sw, unsigned int offset,
331 			      unsigned int flags)
332 {
333 	u32 ctrl;
334 	int ret;
335 
336 	/*
337 	 * Enable wake on PCIe and USB4 (wake coming from another
338 	 * router).
339 	 */
340 	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
341 			 offset + TB_LC_SX_CTRL, 1);
342 	if (ret)
343 		return ret;
344 
345 	ctrl &= ~(TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD | TB_LC_SX_CTRL_WODPC |
346 		  TB_LC_SX_CTRL_WODPD | TB_LC_SX_CTRL_WOP | TB_LC_SX_CTRL_WOU4);
347 
348 	if (flags & TB_WAKE_ON_CONNECT)
349 		ctrl |= TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD;
350 	if (flags & TB_WAKE_ON_USB4)
351 		ctrl |= TB_LC_SX_CTRL_WOU4;
352 	if (flags & TB_WAKE_ON_PCIE)
353 		ctrl |= TB_LC_SX_CTRL_WOP;
354 	if (flags & TB_WAKE_ON_DP)
355 		ctrl |= TB_LC_SX_CTRL_WODPC | TB_LC_SX_CTRL_WODPD;
356 
357 	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, offset + TB_LC_SX_CTRL, 1);
358 }
359 
360 /**
361  * tb_lc_set_wake() - Enable/disable wake
362  * @sw: Switch whose wakes to configure
363  * @flags: Wakeup flags (%0 to disable)
364  *
365  * For each LC sets wake bits accordingly.
366  */
367 int tb_lc_set_wake(struct tb_switch *sw, unsigned int flags)
368 {
369 	int start, size, nlc, ret, i;
370 	u32 desc;
371 
372 	if (sw->generation < 2)
373 		return 0;
374 
375 	if (!tb_route(sw))
376 		return 0;
377 
378 	ret = read_lc_desc(sw, &desc);
379 	if (ret)
380 		return ret;
381 
382 	/* Figure out number of link controllers */
383 	nlc = desc & TB_LC_DESC_NLC_MASK;
384 	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
385 	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
386 
387 	/* For each link controller set sleep bit */
388 	for (i = 0; i < nlc; i++) {
389 		unsigned int offset = sw->cap_lc + start + i * size;
390 
391 		ret = tb_lc_set_wake_one(sw, offset, flags);
392 		if (ret)
393 			return ret;
394 	}
395 
396 	return 0;
397 }
398 
399 /**
400  * tb_lc_set_sleep() - Inform LC that the switch is going to sleep
401  * @sw: Switch to set sleep
402  *
403  * Let the switch link controllers know that the switch is going to
404  * sleep.
405  */
406 int tb_lc_set_sleep(struct tb_switch *sw)
407 {
408 	int start, size, nlc, ret, i;
409 	u32 desc;
410 
411 	if (sw->generation < 2)
412 		return 0;
413 
414 	ret = read_lc_desc(sw, &desc);
415 	if (ret)
416 		return ret;
417 
418 	/* Figure out number of link controllers */
419 	nlc = desc & TB_LC_DESC_NLC_MASK;
420 	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
421 	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
422 
423 	/* For each link controller set sleep bit */
424 	for (i = 0; i < nlc; i++) {
425 		unsigned int offset = sw->cap_lc + start + i * size;
426 		u32 ctrl;
427 
428 		ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
429 				 offset + TB_LC_SX_CTRL, 1);
430 		if (ret)
431 			return ret;
432 
433 		ctrl |= TB_LC_SX_CTRL_SLP;
434 		ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
435 				  offset + TB_LC_SX_CTRL, 1);
436 		if (ret)
437 			return ret;
438 	}
439 
440 	return 0;
441 }
442 
443 /**
444  * tb_lc_lane_bonding_possible() - Is lane bonding possible towards switch
445  * @sw: Switch to check
446  *
447  * Checks whether conditions for lane bonding from parent to @sw are
448  * possible.
449  */
450 bool tb_lc_lane_bonding_possible(struct tb_switch *sw)
451 {
452 	struct tb_port *up;
453 	int cap, ret;
454 	u32 val;
455 
456 	if (sw->generation < 2)
457 		return false;
458 
459 	up = tb_upstream_port(sw);
460 	cap = find_port_lc_cap(up);
461 	if (cap < 0)
462 		return false;
463 
464 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_ATTR, 1);
465 	if (ret)
466 		return false;
467 
468 	return !!(val & TB_LC_PORT_ATTR_BE);
469 }
470 
471 static int tb_lc_dp_sink_from_port(const struct tb_switch *sw,
472 				   struct tb_port *in)
473 {
474 	struct tb_port *port;
475 
476 	/* The first DP IN port is sink 0 and second is sink 1 */
477 	tb_switch_for_each_port(sw, port) {
478 		if (tb_port_is_dpin(port))
479 			return in != port;
480 	}
481 
482 	return -EINVAL;
483 }
484 
485 static int tb_lc_dp_sink_available(struct tb_switch *sw, int sink)
486 {
487 	u32 val, alloc;
488 	int ret;
489 
490 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
491 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
492 	if (ret)
493 		return ret;
494 
495 	/*
496 	 * Sink is available for CM/SW to use if the allocation valie is
497 	 * either 0 or 1.
498 	 */
499 	if (!sink) {
500 		alloc = val & TB_LC_SNK_ALLOCATION_SNK0_MASK;
501 		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK0_CM)
502 			return 0;
503 	} else {
504 		alloc = (val & TB_LC_SNK_ALLOCATION_SNK1_MASK) >>
505 			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
506 		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK1_CM)
507 			return 0;
508 	}
509 
510 	return -EBUSY;
511 }
512 
513 /**
514  * tb_lc_dp_sink_query() - Is DP sink available for DP IN port
515  * @sw: Switch whose DP sink is queried
516  * @in: DP IN port to check
517  *
518  * Queries through LC SNK_ALLOCATION registers whether DP sink is available
519  * for the given DP IN port or not.
520  */
521 bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in)
522 {
523 	int sink;
524 
525 	/*
526 	 * For older generations sink is always available as there is no
527 	 * allocation mechanism.
528 	 */
529 	if (sw->generation < 3)
530 		return true;
531 
532 	sink = tb_lc_dp_sink_from_port(sw, in);
533 	if (sink < 0)
534 		return false;
535 
536 	return !tb_lc_dp_sink_available(sw, sink);
537 }
538 
539 /**
540  * tb_lc_dp_sink_alloc() - Allocate DP sink
541  * @sw: Switch whose DP sink is allocated
542  * @in: DP IN port the DP sink is allocated for
543  *
544  * Allocate DP sink for @in via LC SNK_ALLOCATION registers. If the
545  * resource is available and allocation is successful returns %0. In all
546  * other cases returs negative errno. In particular %-EBUSY is returned if
547  * the resource was not available.
548  */
549 int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in)
550 {
551 	int ret, sink;
552 	u32 val;
553 
554 	if (sw->generation < 3)
555 		return 0;
556 
557 	sink = tb_lc_dp_sink_from_port(sw, in);
558 	if (sink < 0)
559 		return sink;
560 
561 	ret = tb_lc_dp_sink_available(sw, sink);
562 	if (ret)
563 		return ret;
564 
565 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
566 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
567 	if (ret)
568 		return ret;
569 
570 	if (!sink) {
571 		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
572 		val |= TB_LC_SNK_ALLOCATION_SNK0_CM;
573 	} else {
574 		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
575 		val |= TB_LC_SNK_ALLOCATION_SNK1_CM <<
576 			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
577 	}
578 
579 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
580 			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
581 
582 	if (ret)
583 		return ret;
584 
585 	tb_port_dbg(in, "sink %d allocated\n", sink);
586 	return 0;
587 }
588 
589 /**
590  * tb_lc_dp_sink_dealloc() - De-allocate DP sink
591  * @sw: Switch whose DP sink is de-allocated
592  * @in: DP IN port whose DP sink is de-allocated
593  *
594  * De-allocate DP sink from @in using LC SNK_ALLOCATION registers.
595  */
596 int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in)
597 {
598 	int ret, sink;
599 	u32 val;
600 
601 	if (sw->generation < 3)
602 		return 0;
603 
604 	sink = tb_lc_dp_sink_from_port(sw, in);
605 	if (sink < 0)
606 		return sink;
607 
608 	/* Needs to be owned by CM/SW */
609 	ret = tb_lc_dp_sink_available(sw, sink);
610 	if (ret)
611 		return ret;
612 
613 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
614 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
615 	if (ret)
616 		return ret;
617 
618 	if (!sink)
619 		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
620 	else
621 		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
622 
623 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
624 			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
625 	if (ret)
626 		return ret;
627 
628 	tb_port_dbg(in, "sink %d de-allocated\n", sink);
629 	return 0;
630 }
631 
632 /**
633  * tb_lc_force_power() - Forces LC to be powered on
634  * @sw: Thunderbolt switch
635  *
636  * This is useful to let authentication cycle pass even without
637  * a Thunderbolt link present.
638  */
639 int tb_lc_force_power(struct tb_switch *sw)
640 {
641 	u32 in = 0xffff;
642 
643 	return tb_sw_write(sw, &in, TB_CFG_SWITCH, TB_LC_POWER, 1);
644 }
645