xref: /openbmc/linux/drivers/thunderbolt/lc.c (revision 2cf1c348)
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 static int tb_lc_set_wake_one(struct tb_switch *sw, unsigned int offset,
221 			      unsigned int flags)
222 {
223 	u32 ctrl;
224 	int ret;
225 
226 	/*
227 	 * Enable wake on PCIe and USB4 (wake coming from another
228 	 * router).
229 	 */
230 	ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
231 			 offset + TB_LC_SX_CTRL, 1);
232 	if (ret)
233 		return ret;
234 
235 	ctrl &= ~(TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD | TB_LC_SX_CTRL_WODPC |
236 		  TB_LC_SX_CTRL_WODPD | TB_LC_SX_CTRL_WOP | TB_LC_SX_CTRL_WOU4);
237 
238 	if (flags & TB_WAKE_ON_CONNECT)
239 		ctrl |= TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD;
240 	if (flags & TB_WAKE_ON_USB4)
241 		ctrl |= TB_LC_SX_CTRL_WOU4;
242 	if (flags & TB_WAKE_ON_PCIE)
243 		ctrl |= TB_LC_SX_CTRL_WOP;
244 	if (flags & TB_WAKE_ON_DP)
245 		ctrl |= TB_LC_SX_CTRL_WODPC | TB_LC_SX_CTRL_WODPD;
246 
247 	return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, offset + TB_LC_SX_CTRL, 1);
248 }
249 
250 /**
251  * tb_lc_set_wake() - Enable/disable wake
252  * @sw: Switch whose wakes to configure
253  * @flags: Wakeup flags (%0 to disable)
254  *
255  * For each LC sets wake bits accordingly.
256  */
257 int tb_lc_set_wake(struct tb_switch *sw, unsigned int flags)
258 {
259 	int start, size, nlc, ret, i;
260 	u32 desc;
261 
262 	if (sw->generation < 2)
263 		return 0;
264 
265 	if (!tb_route(sw))
266 		return 0;
267 
268 	ret = read_lc_desc(sw, &desc);
269 	if (ret)
270 		return ret;
271 
272 	/* Figure out number of link controllers */
273 	nlc = desc & TB_LC_DESC_NLC_MASK;
274 	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
275 	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
276 
277 	/* For each link controller set sleep bit */
278 	for (i = 0; i < nlc; i++) {
279 		unsigned int offset = sw->cap_lc + start + i * size;
280 
281 		ret = tb_lc_set_wake_one(sw, offset, flags);
282 		if (ret)
283 			return ret;
284 	}
285 
286 	return 0;
287 }
288 
289 /**
290  * tb_lc_set_sleep() - Inform LC that the switch is going to sleep
291  * @sw: Switch to set sleep
292  *
293  * Let the switch link controllers know that the switch is going to
294  * sleep.
295  */
296 int tb_lc_set_sleep(struct tb_switch *sw)
297 {
298 	int start, size, nlc, ret, i;
299 	u32 desc;
300 
301 	if (sw->generation < 2)
302 		return 0;
303 
304 	ret = read_lc_desc(sw, &desc);
305 	if (ret)
306 		return ret;
307 
308 	/* Figure out number of link controllers */
309 	nlc = desc & TB_LC_DESC_NLC_MASK;
310 	start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
311 	size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
312 
313 	/* For each link controller set sleep bit */
314 	for (i = 0; i < nlc; i++) {
315 		unsigned int offset = sw->cap_lc + start + i * size;
316 		u32 ctrl;
317 
318 		ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
319 				 offset + TB_LC_SX_CTRL, 1);
320 		if (ret)
321 			return ret;
322 
323 		ctrl |= TB_LC_SX_CTRL_SLP;
324 		ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
325 				  offset + TB_LC_SX_CTRL, 1);
326 		if (ret)
327 			return ret;
328 	}
329 
330 	return 0;
331 }
332 
333 /**
334  * tb_lc_lane_bonding_possible() - Is lane bonding possible towards switch
335  * @sw: Switch to check
336  *
337  * Checks whether conditions for lane bonding from parent to @sw are
338  * possible.
339  */
340 bool tb_lc_lane_bonding_possible(struct tb_switch *sw)
341 {
342 	struct tb_port *up;
343 	int cap, ret;
344 	u32 val;
345 
346 	if (sw->generation < 2)
347 		return false;
348 
349 	up = tb_upstream_port(sw);
350 	cap = find_port_lc_cap(up);
351 	if (cap < 0)
352 		return false;
353 
354 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_ATTR, 1);
355 	if (ret)
356 		return false;
357 
358 	return !!(val & TB_LC_PORT_ATTR_BE);
359 }
360 
361 static int tb_lc_dp_sink_from_port(const struct tb_switch *sw,
362 				   struct tb_port *in)
363 {
364 	struct tb_port *port;
365 
366 	/* The first DP IN port is sink 0 and second is sink 1 */
367 	tb_switch_for_each_port(sw, port) {
368 		if (tb_port_is_dpin(port))
369 			return in != port;
370 	}
371 
372 	return -EINVAL;
373 }
374 
375 static int tb_lc_dp_sink_available(struct tb_switch *sw, int sink)
376 {
377 	u32 val, alloc;
378 	int ret;
379 
380 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
381 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
382 	if (ret)
383 		return ret;
384 
385 	/*
386 	 * Sink is available for CM/SW to use if the allocation valie is
387 	 * either 0 or 1.
388 	 */
389 	if (!sink) {
390 		alloc = val & TB_LC_SNK_ALLOCATION_SNK0_MASK;
391 		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK0_CM)
392 			return 0;
393 	} else {
394 		alloc = (val & TB_LC_SNK_ALLOCATION_SNK1_MASK) >>
395 			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
396 		if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK1_CM)
397 			return 0;
398 	}
399 
400 	return -EBUSY;
401 }
402 
403 /**
404  * tb_lc_dp_sink_query() - Is DP sink available for DP IN port
405  * @sw: Switch whose DP sink is queried
406  * @in: DP IN port to check
407  *
408  * Queries through LC SNK_ALLOCATION registers whether DP sink is available
409  * for the given DP IN port or not.
410  */
411 bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in)
412 {
413 	int sink;
414 
415 	/*
416 	 * For older generations sink is always available as there is no
417 	 * allocation mechanism.
418 	 */
419 	if (sw->generation < 3)
420 		return true;
421 
422 	sink = tb_lc_dp_sink_from_port(sw, in);
423 	if (sink < 0)
424 		return false;
425 
426 	return !tb_lc_dp_sink_available(sw, sink);
427 }
428 
429 /**
430  * tb_lc_dp_sink_alloc() - Allocate DP sink
431  * @sw: Switch whose DP sink is allocated
432  * @in: DP IN port the DP sink is allocated for
433  *
434  * Allocate DP sink for @in via LC SNK_ALLOCATION registers. If the
435  * resource is available and allocation is successful returns %0. In all
436  * other cases returs negative errno. In particular %-EBUSY is returned if
437  * the resource was not available.
438  */
439 int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in)
440 {
441 	int ret, sink;
442 	u32 val;
443 
444 	if (sw->generation < 3)
445 		return 0;
446 
447 	sink = tb_lc_dp_sink_from_port(sw, in);
448 	if (sink < 0)
449 		return sink;
450 
451 	ret = tb_lc_dp_sink_available(sw, sink);
452 	if (ret)
453 		return ret;
454 
455 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
456 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
457 	if (ret)
458 		return ret;
459 
460 	if (!sink) {
461 		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
462 		val |= TB_LC_SNK_ALLOCATION_SNK0_CM;
463 	} else {
464 		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
465 		val |= TB_LC_SNK_ALLOCATION_SNK1_CM <<
466 			TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
467 	}
468 
469 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
470 			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
471 
472 	if (ret)
473 		return ret;
474 
475 	tb_port_dbg(in, "sink %d allocated\n", sink);
476 	return 0;
477 }
478 
479 /**
480  * tb_lc_dp_sink_dealloc() - De-allocate DP sink
481  * @sw: Switch whose DP sink is de-allocated
482  * @in: DP IN port whose DP sink is de-allocated
483  *
484  * De-allocate DP sink from @in using LC SNK_ALLOCATION registers.
485  */
486 int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in)
487 {
488 	int ret, sink;
489 	u32 val;
490 
491 	if (sw->generation < 3)
492 		return 0;
493 
494 	sink = tb_lc_dp_sink_from_port(sw, in);
495 	if (sink < 0)
496 		return sink;
497 
498 	/* Needs to be owned by CM/SW */
499 	ret = tb_lc_dp_sink_available(sw, sink);
500 	if (ret)
501 		return ret;
502 
503 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
504 			 sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
505 	if (ret)
506 		return ret;
507 
508 	if (!sink)
509 		val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
510 	else
511 		val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
512 
513 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
514 			  sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
515 	if (ret)
516 		return ret;
517 
518 	tb_port_dbg(in, "sink %d de-allocated\n", sink);
519 	return 0;
520 }
521 
522 /**
523  * tb_lc_force_power() - Forces LC to be powered on
524  * @sw: Thunderbolt switch
525  *
526  * This is useful to let authentication cycle pass even without
527  * a Thunderbolt link present.
528  */
529 int tb_lc_force_power(struct tb_switch *sw)
530 {
531 	u32 in = 0xffff;
532 
533 	return tb_sw_write(sw, &in, TB_CFG_SWITCH, TB_LC_POWER, 1);
534 }
535