xref: /linux/drivers/thunderbolt/usb4.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB4 specific functionality
4  *
5  * Copyright (C) 2019, Intel Corporation
6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
7  *	    Rajmohan Mani <rajmohan.mani@intel.com>
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/ktime.h>
12 #include <linux/string_choices.h>
13 #include <linux/units.h>
14 
15 #include "sb_regs.h"
16 #include "tb.h"
17 
18 #define USB4_DATA_RETRIES		3
19 #define USB4_DATA_DWORDS		16
20 
21 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
22 #define USB4_NVM_READ_OFFSET_SHIFT	2
23 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
24 #define USB4_NVM_READ_LENGTH_SHIFT	24
25 
26 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
27 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
28 
29 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
30 #define USB4_DROM_ADDRESS_SHIFT		2
31 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
32 #define USB4_DROM_SIZE_SHIFT		15
33 
34 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
35 
36 #define USB4_BA_LENGTH_MASK		GENMASK(7, 0)
37 #define USB4_BA_INDEX_MASK		GENMASK(15, 0)
38 
39 enum usb4_ba_index {
40 	USB4_BA_MAX_USB3 = 0x1,
41 	USB4_BA_MIN_DP_AUX = 0x2,
42 	USB4_BA_MIN_DP_MAIN = 0x3,
43 	USB4_BA_MAX_PCIE = 0x4,
44 	USB4_BA_MAX_HI = 0x5,
45 };
46 
47 #define USB4_BA_VALUE_MASK		GENMASK(31, 16)
48 #define USB4_BA_VALUE_SHIFT		16
49 
50 /* Delays in us used with usb4_port_wait_for_bit() */
51 #define USB4_PORT_DELAY			50
52 #define USB4_PORT_SB_DELAY		1000
53 
54 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
55 				 u32 *metadata, u8 *status,
56 				 const void *tx_data, size_t tx_dwords,
57 				 void *rx_data, size_t rx_dwords)
58 {
59 	u32 val;
60 	int ret;
61 
62 	if (metadata) {
63 		ret = tb_sw_write(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
64 		if (ret)
65 			return ret;
66 	}
67 	if (tx_dwords) {
68 		ret = tb_sw_write(sw, tx_data, TB_CFG_SWITCH, ROUTER_CS_9,
69 				  tx_dwords);
70 		if (ret)
71 			return ret;
72 	}
73 
74 	val = opcode | ROUTER_CS_26_OV;
75 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
76 	if (ret)
77 		return ret;
78 
79 	ret = tb_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
80 	if (ret)
81 		return ret;
82 
83 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
84 	if (ret)
85 		return ret;
86 
87 	if (val & ROUTER_CS_26_ONS)
88 		return -EOPNOTSUPP;
89 
90 	if (status)
91 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
92 			ROUTER_CS_26_STATUS_SHIFT;
93 
94 	if (metadata) {
95 		ret = tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
96 		if (ret)
97 			return ret;
98 	}
99 	if (rx_dwords) {
100 		ret = tb_sw_read(sw, rx_data, TB_CFG_SWITCH, ROUTER_CS_9,
101 				 rx_dwords);
102 		if (ret)
103 			return ret;
104 	}
105 
106 	return 0;
107 }
108 
109 static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
110 			    u8 *status, const void *tx_data, size_t tx_dwords,
111 			    void *rx_data, size_t rx_dwords)
112 {
113 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
114 
115 	if (tx_dwords > USB4_DATA_DWORDS || rx_dwords > USB4_DATA_DWORDS)
116 		return -EINVAL;
117 
118 	/*
119 	 * If the connection manager implementation provides USB4 router
120 	 * operation proxy callback, call it here instead of running the
121 	 * operation natively.
122 	 */
123 	if (cm_ops->usb4_switch_op) {
124 		int ret;
125 
126 		ret = cm_ops->usb4_switch_op(sw, opcode, metadata, status,
127 					     tx_data, tx_dwords, rx_data,
128 					     rx_dwords);
129 		if (ret != -EOPNOTSUPP)
130 			return ret;
131 
132 		/*
133 		 * If the proxy was not supported then run the native
134 		 * router operation instead.
135 		 */
136 	}
137 
138 	return usb4_native_switch_op(sw, opcode, metadata, status, tx_data,
139 				     tx_dwords, rx_data, rx_dwords);
140 }
141 
142 static inline int usb4_switch_op(struct tb_switch *sw, u16 opcode,
143 				 u32 *metadata, u8 *status)
144 {
145 	return __usb4_switch_op(sw, opcode, metadata, status, NULL, 0, NULL, 0);
146 }
147 
148 static inline int usb4_switch_op_data(struct tb_switch *sw, u16 opcode,
149 				      u32 *metadata, u8 *status,
150 				      const void *tx_data, size_t tx_dwords,
151 				      void *rx_data, size_t rx_dwords)
152 {
153 	return __usb4_switch_op(sw, opcode, metadata, status, tx_data,
154 				tx_dwords, rx_data, rx_dwords);
155 }
156 
157 /**
158  * usb4_switch_check_wakes() - Check for wakes and notify PM core about them
159  * @sw: Router whose wakes to check
160  *
161  * Checks wakes occurred during suspend and notify the PM core about them.
162  */
163 void usb4_switch_check_wakes(struct tb_switch *sw)
164 {
165 	bool wakeup_usb4 = false;
166 	struct usb4_port *usb4;
167 	struct tb_port *port;
168 	bool wakeup = false;
169 	u32 val;
170 
171 	if (tb_route(sw)) {
172 		if (tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1))
173 			return;
174 
175 		tb_sw_dbg(sw, "PCIe wake: %s, USB3 wake: %s\n",
176 			  str_yes_no(val & ROUTER_CS_6_WOPS),
177 			  str_yes_no(val & ROUTER_CS_6_WOUS));
178 
179 		wakeup = val & (ROUTER_CS_6_WOPS | ROUTER_CS_6_WOUS);
180 	}
181 
182 	/*
183 	 * Check for any downstream ports for USB4 wake,
184 	 * connection wake and disconnection wake.
185 	 */
186 	tb_switch_for_each_port(sw, port) {
187 		if (!port->cap_usb4)
188 			continue;
189 
190 		if (tb_port_read(port, &val, TB_CFG_PORT,
191 				 port->cap_usb4 + PORT_CS_18, 1))
192 			break;
193 
194 		tb_port_dbg(port, "USB4 wake: %s, connection wake: %s, disconnection wake: %s\n",
195 			    str_yes_no(val & PORT_CS_18_WOU4S),
196 			    str_yes_no(val & PORT_CS_18_WOCS),
197 			    str_yes_no(val & PORT_CS_18_WODS));
198 
199 		wakeup_usb4 = val & (PORT_CS_18_WOU4S | PORT_CS_18_WOCS |
200 				     PORT_CS_18_WODS);
201 
202 		usb4 = port->usb4;
203 		if (device_may_wakeup(&usb4->dev) && wakeup_usb4)
204 			pm_wakeup_event(&usb4->dev, 0);
205 
206 		wakeup |= wakeup_usb4;
207 	}
208 
209 	if (wakeup)
210 		pm_wakeup_event(&sw->dev, 0);
211 }
212 
213 static bool link_is_usb4(struct tb_port *port)
214 {
215 	u32 val;
216 
217 	if (!port->cap_usb4)
218 		return false;
219 
220 	if (tb_port_read(port, &val, TB_CFG_PORT,
221 			 port->cap_usb4 + PORT_CS_18, 1))
222 		return false;
223 
224 	return !(val & PORT_CS_18_TCM);
225 }
226 
227 /**
228  * usb4_switch_setup() - Additional setup for USB4 device
229  * @sw: USB4 router to setup
230  *
231  * USB4 routers need additional settings in order to enable all the
232  * tunneling. This function enables USB and PCIe tunneling if it can be
233  * enabled (e.g the parent switch also supports them). If USB tunneling
234  * is not available for some reason (like that there is Thunderbolt 3
235  * switch upstream) then the internal xHCI controller is enabled
236  * instead.
237  *
238  * This does not set the configuration valid bit of the router. To do
239  * that call usb4_switch_configuration_valid().
240  *
241  * Return: %0 on success, negative errno otherwise.
242  */
243 int usb4_switch_setup(struct tb_switch *sw)
244 {
245 	struct tb_switch *parent = tb_switch_parent(sw);
246 	struct tb_port *down;
247 	bool tbt3, xhci;
248 	u32 val = 0;
249 	int ret;
250 
251 	if (!tb_route(sw))
252 		return 0;
253 
254 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
255 	if (ret)
256 		return ret;
257 
258 	down = tb_switch_downstream_port(sw);
259 	sw->link_usb4 = link_is_usb4(down);
260 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT");
261 
262 	xhci = val & ROUTER_CS_6_HCI;
263 	tbt3 = !(val & ROUTER_CS_6_TNS);
264 
265 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
266 		  str_yes_no(tbt3), str_yes_no(xhci));
267 
268 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
269 	if (ret)
270 		return ret;
271 
272 	if (tb_acpi_may_tunnel_usb3() && sw->link_usb4 &&
273 	    tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
274 		val |= ROUTER_CS_5_UTO;
275 		xhci = false;
276 	}
277 
278 	/*
279 	 * Only enable PCIe tunneling if the parent router supports it
280 	 * and it is not disabled.
281 	 */
282 	if (tb_acpi_may_tunnel_pcie() &&
283 	    tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
284 		val |= ROUTER_CS_5_PTO;
285 		/*
286 		 * xHCI can be enabled if PCIe tunneling is supported
287 		 * and the parent does not have any USB3 dowstream
288 		 * adapters (so we cannot do USB 3.x tunneling).
289 		 */
290 		if (xhci)
291 			val |= ROUTER_CS_5_HCO;
292 	}
293 
294 	/* TBT3 supported by the CM */
295 	val &= ~ROUTER_CS_5_CNS;
296 
297 	return tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
298 }
299 
300 /**
301  * usb4_switch_configuration_valid() - Set tunneling configuration to be valid
302  * @sw: USB4 router
303  *
304  * Sets configuration valid bit for the router. Must be called before
305  * any tunnels can be set through the router and after
306  * usb4_switch_setup() has been called. Can be called to host and device
307  * routers (does nothing for the latter).
308  *
309  * Return: %0 on success, negative errno otherwise.
310  */
311 int usb4_switch_configuration_valid(struct tb_switch *sw)
312 {
313 	u32 val;
314 	int ret;
315 
316 	if (!tb_route(sw))
317 		return 0;
318 
319 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
320 	if (ret)
321 		return ret;
322 
323 	val |= ROUTER_CS_5_CV;
324 
325 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
326 	if (ret)
327 		return ret;
328 
329 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
330 				      ROUTER_CS_6_CR, 50);
331 }
332 
333 /**
334  * usb4_switch_read_uid() - Read UID from USB4 router
335  * @sw: USB4 router
336  * @uid: UID is stored here
337  *
338  * Reads 64-bit UID from USB4 router config space.
339  *
340  * Return: %0 on success, negative errno otherwise.
341  */
342 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
343 {
344 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
345 }
346 
347 static int usb4_switch_drom_read_block(void *data,
348 				       unsigned int dwaddress, void *buf,
349 				       size_t dwords)
350 {
351 	struct tb_switch *sw = data;
352 	u8 status = 0;
353 	u32 metadata;
354 	int ret;
355 
356 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
357 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
358 		USB4_DROM_ADDRESS_MASK;
359 
360 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
361 				  &status, NULL, 0, buf, dwords);
362 	if (ret)
363 		return ret;
364 
365 	return status ? -EIO : 0;
366 }
367 
368 /**
369  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
370  * @sw: USB4 router
371  * @address: Byte address inside DROM to start reading
372  * @buf: Buffer where the DROM content is stored
373  * @size: Number of bytes to read from DROM
374  *
375  * Uses USB4 router operations to read router DROM. For devices this
376  * should always work but for hosts it may return %-EOPNOTSUPP in which
377  * case the host router does not have DROM.
378  *
379  * Return: %0 on success, negative errno otherwise.
380  */
381 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
382 			  size_t size)
383 {
384 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
385 				usb4_switch_drom_read_block, sw);
386 }
387 
388 /**
389  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
390  * @sw: USB4 router
391  *
392  * Checks whether conditions are met so that lane bonding can be
393  * established with the upstream router. Call only for device routers.
394  *
395  * Return: %true if lane bonding is possible, %false otherwise.
396  */
397 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
398 {
399 	struct tb_port *up;
400 	int ret;
401 	u32 val;
402 
403 	up = tb_upstream_port(sw);
404 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
405 	if (ret)
406 		return false;
407 
408 	return !!(val & PORT_CS_18_BE);
409 }
410 
411 /**
412  * usb4_switch_set_wake() - Enabled/disable wake
413  * @sw: USB4 router
414  * @flags: Wakeup flags (%0 to disable)
415  * @runtime: Wake is being programmed during system runtime
416  *
417  * Enables/disables router to wake up from sleep.
418  *
419  * Return: %0 on success, negative errno otherwise.
420  */
421 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags, bool runtime)
422 {
423 	struct tb_port *port;
424 	u64 route = tb_route(sw);
425 	u32 val;
426 	int ret;
427 
428 	/*
429 	 * Enable wakes coming from all USB4 downstream ports (from
430 	 * child routers). For device routers do this also for the
431 	 * upstream USB4 port.
432 	 */
433 	tb_switch_for_each_port(sw, port) {
434 		if (!tb_port_is_null(port))
435 			continue;
436 		if (!route && tb_is_upstream_port(port))
437 			continue;
438 		if (!port->cap_usb4)
439 			continue;
440 
441 		ret = tb_port_read(port, &val, TB_CFG_PORT,
442 				   port->cap_usb4 + PORT_CS_19, 1);
443 		if (ret)
444 			return ret;
445 
446 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
447 
448 		if (tb_is_upstream_port(port)) {
449 			val |= PORT_CS_19_WOU4;
450 		} else {
451 			bool configured = val & PORT_CS_19_PC;
452 			bool wakeup = runtime || device_may_wakeup(&port->usb4->dev);
453 
454 			if ((flags & TB_WAKE_ON_CONNECT) && wakeup && !configured)
455 				val |= PORT_CS_19_WOC;
456 			if ((flags & TB_WAKE_ON_DISCONNECT) && wakeup && configured)
457 				val |= PORT_CS_19_WOD;
458 			if ((flags & TB_WAKE_ON_USB4) && configured)
459 				val |= PORT_CS_19_WOU4;
460 		}
461 
462 		ret = tb_port_write(port, &val, TB_CFG_PORT,
463 				    port->cap_usb4 + PORT_CS_19, 1);
464 		if (ret)
465 			return ret;
466 	}
467 
468 	/*
469 	 * Enable wakes from PCIe, USB 3.x and DP on this router. Only
470 	 * needed for device routers.
471 	 */
472 	if (route) {
473 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
474 		if (ret)
475 			return ret;
476 
477 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU | ROUTER_CS_5_WOD);
478 		if (flags & TB_WAKE_ON_USB3)
479 			val |= ROUTER_CS_5_WOU;
480 		if (flags & TB_WAKE_ON_PCIE)
481 			val |= ROUTER_CS_5_WOP;
482 		if (flags & TB_WAKE_ON_DP)
483 			val |= ROUTER_CS_5_WOD;
484 
485 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
486 		if (ret)
487 			return ret;
488 	}
489 
490 	return 0;
491 }
492 
493 /**
494  * usb4_switch_set_sleep() - Prepare the router to enter sleep
495  * @sw: USB4 router
496  *
497  * Sets sleep bit for the router and waits until router sleep ready
498  * bit has been asserted.
499  *
500  * Return: %0 on success, negative errno otherwise.
501  */
502 int usb4_switch_set_sleep(struct tb_switch *sw)
503 {
504 	int ret;
505 	u32 val;
506 
507 	/* Set sleep bit and wait for sleep ready to be asserted */
508 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
509 	if (ret)
510 		return ret;
511 
512 	val |= ROUTER_CS_5_SLP;
513 
514 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
515 	if (ret)
516 		return ret;
517 
518 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
519 				      ROUTER_CS_6_SLPR, 500);
520 }
521 
522 /**
523  * usb4_switch_nvm_sector_size() - Return router NVM sector size
524  * @sw: USB4 router
525  *
526  * Return:
527  * * NVM sector size in bytes if router supports NVM operations.
528  * * %-EOPNOTSUPP - If router does not support NVM operations.
529  * * Negative errno - Another error occurred.
530  */
531 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
532 {
533 	u32 metadata;
534 	u8 status;
535 	int ret;
536 
537 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
538 			     &status);
539 	if (ret)
540 		return ret;
541 
542 	if (status)
543 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
544 
545 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
546 }
547 
548 static int usb4_switch_nvm_read_block(void *data,
549 	unsigned int dwaddress, void *buf, size_t dwords)
550 {
551 	struct tb_switch *sw = data;
552 	u8 status = 0;
553 	u32 metadata;
554 	int ret;
555 
556 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
557 		   USB4_NVM_READ_LENGTH_MASK;
558 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
559 		   USB4_NVM_READ_OFFSET_MASK;
560 
561 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
562 				  &status, NULL, 0, buf, dwords);
563 	if (ret)
564 		return ret;
565 
566 	return status ? -EIO : 0;
567 }
568 
569 /**
570  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
571  * @sw: USB4 router
572  * @address: Starting address in bytes
573  * @buf: Read data is placed here
574  * @size: How many bytes to read
575  *
576  * Reads NVM contents of the router.
577  *
578  * Return:
579  * * %0 - Read completed successfully.
580  * * %-EOPNOTSUPP - NVM not supported.
581  * * Negative errno - Another error occurred.
582  */
583 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
584 			 size_t size)
585 {
586 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
587 				usb4_switch_nvm_read_block, sw);
588 }
589 
590 /**
591  * usb4_switch_nvm_set_offset() - Set NVM write offset
592  * @sw: USB4 router
593  * @address: Start offset
594  *
595  * Explicitly sets NVM write offset. Normally when writing to NVM this
596  * is done automatically by usb4_switch_nvm_write().
597  *
598  * Return: %0 on success, negative errno otherwise.
599  */
600 int usb4_switch_nvm_set_offset(struct tb_switch *sw, unsigned int address)
601 {
602 	u32 metadata, dwaddress;
603 	u8 status = 0;
604 	int ret;
605 
606 	dwaddress = address / 4;
607 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
608 		   USB4_NVM_SET_OFFSET_MASK;
609 
610 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
611 			     &status);
612 	if (ret)
613 		return ret;
614 
615 	return status ? -EIO : 0;
616 }
617 
618 static int usb4_switch_nvm_write_next_block(void *data, unsigned int dwaddress,
619 					    const void *buf, size_t dwords)
620 {
621 	struct tb_switch *sw = data;
622 	u8 status;
623 	int ret;
624 
625 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
626 				  buf, dwords, NULL, 0);
627 	if (ret)
628 		return ret;
629 
630 	return status ? -EIO : 0;
631 }
632 
633 /**
634  * usb4_switch_nvm_write() - Write to the router NVM
635  * @sw: USB4 router
636  * @address: Start address where to write in bytes
637  * @buf: Pointer to the data to write
638  * @size: Size of @buf in bytes
639  *
640  * Writes @buf to the router NVM using USB4 router operations.
641  *
642  * Return:
643  * * %0 - Write completed successfully.
644  * * %-EOPNOTSUPP - NVM write not supported.
645  * * Negative errno - Another error occurred.
646  */
647 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
648 			  const void *buf, size_t size)
649 {
650 	int ret;
651 
652 	ret = usb4_switch_nvm_set_offset(sw, address);
653 	if (ret)
654 		return ret;
655 
656 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
657 				 usb4_switch_nvm_write_next_block, sw);
658 }
659 
660 /**
661  * usb4_switch_nvm_authenticate() - Authenticate new NVM
662  * @sw: USB4 router
663  *
664  * After the new NVM has been written via usb4_switch_nvm_write(), this
665  * function triggers NVM authentication process. The router gets power
666  * cycled and if the authentication is successful the new NVM starts
667  * running.
668  *
669  * The caller should call usb4_switch_nvm_authenticate_status() to read
670  * the status of the authentication after power cycle. It should be the
671  * first router operation to avoid the status being lost.
672  *
673  * Return: %0 on success, negative errno otherwise.
674  */
675 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
676 {
677 	int ret;
678 
679 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
680 	switch (ret) {
681 	/*
682 	 * The router is power cycled once NVM_AUTH is started so it is
683 	 * expected to get any of the following errors back.
684 	 */
685 	case -EACCES:
686 	case -ENOTCONN:
687 	case -ETIMEDOUT:
688 		return 0;
689 
690 	default:
691 		return ret;
692 	}
693 }
694 
695 /**
696  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
697  * @sw: USB4 router
698  * @status: Status code of the operation
699  *
700  * The function checks if there is status available from the last NVM
701  * authenticate router operation.
702  *
703  * Must be called before any other router operation.
704  *
705  * Return:
706  * * %0 - If there is status. Status code is placed in @status.
707  * * Negative errno - Failure occurred.
708  */
709 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
710 {
711 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
712 	u16 opcode;
713 	u32 val;
714 	int ret;
715 
716 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
717 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
718 		if (ret != -EOPNOTSUPP)
719 			return ret;
720 	}
721 
722 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
723 	if (ret)
724 		return ret;
725 
726 	/* Check that the opcode is correct */
727 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
728 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
729 		if (val & ROUTER_CS_26_OV)
730 			return -EBUSY;
731 		if (val & ROUTER_CS_26_ONS)
732 			return -EOPNOTSUPP;
733 
734 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
735 			ROUTER_CS_26_STATUS_SHIFT;
736 	} else {
737 		*status = 0;
738 	}
739 
740 	return 0;
741 }
742 
743 /**
744  * usb4_switch_credits_init() - Read buffer allocation parameters
745  * @sw: USB4 router
746  *
747  * Reads @sw buffer allocation parameters and initializes @sw buffer
748  * allocation fields accordingly. Specifically @sw->credits_allocation
749  * is set to %true if these parameters can be used in tunneling.
750  *
751  * Return: %0 on success, negative errno otherwise.
752  */
753 int usb4_switch_credits_init(struct tb_switch *sw)
754 {
755 	int max_usb3, min_dp_aux, min_dp_main, max_pcie, max_dma;
756 	int ret, length, i, nports;
757 	const struct tb_port *port;
758 	u32 data[USB4_DATA_DWORDS];
759 	u32 metadata = 0;
760 	u8 status = 0;
761 
762 	memset(data, 0, sizeof(data));
763 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_BUFFER_ALLOC, &metadata,
764 				  &status, NULL, 0, data, ARRAY_SIZE(data));
765 	if (ret)
766 		return ret;
767 	if (status)
768 		return -EIO;
769 
770 	length = metadata & USB4_BA_LENGTH_MASK;
771 	if (WARN_ON(length > ARRAY_SIZE(data)))
772 		return -EMSGSIZE;
773 
774 	max_usb3 = -1;
775 	min_dp_aux = -1;
776 	min_dp_main = -1;
777 	max_pcie = -1;
778 	max_dma = -1;
779 
780 	tb_sw_dbg(sw, "credit allocation parameters:\n");
781 
782 	for (i = 0; i < length; i++) {
783 		u16 index, value;
784 
785 		index = data[i] & USB4_BA_INDEX_MASK;
786 		value = (data[i] & USB4_BA_VALUE_MASK) >> USB4_BA_VALUE_SHIFT;
787 
788 		switch (index) {
789 		case USB4_BA_MAX_USB3:
790 			tb_sw_dbg(sw, " USB3: %u\n", value);
791 			max_usb3 = value;
792 			break;
793 		case USB4_BA_MIN_DP_AUX:
794 			tb_sw_dbg(sw, " DP AUX: %u\n", value);
795 			min_dp_aux = value;
796 			break;
797 		case USB4_BA_MIN_DP_MAIN:
798 			tb_sw_dbg(sw, " DP main: %u\n", value);
799 			min_dp_main = value;
800 			break;
801 		case USB4_BA_MAX_PCIE:
802 			tb_sw_dbg(sw, " PCIe: %u\n", value);
803 			max_pcie = value;
804 			break;
805 		case USB4_BA_MAX_HI:
806 			tb_sw_dbg(sw, " DMA: %u\n", value);
807 			max_dma = value;
808 			break;
809 		default:
810 			tb_sw_dbg(sw, " unknown credit allocation index %#x, skipping\n",
811 				  index);
812 			break;
813 		}
814 	}
815 
816 	/*
817 	 * Validate the buffer allocation preferences. If we find
818 	 * issues, log a warning and fall back using the hard-coded
819 	 * values.
820 	 */
821 
822 	/* Host router must report baMaxHI */
823 	if (!tb_route(sw) && max_dma < 0) {
824 		tb_sw_warn(sw, "host router is missing baMaxHI\n");
825 		goto err_invalid;
826 	}
827 
828 	nports = 0;
829 	tb_switch_for_each_port(sw, port) {
830 		if (tb_port_is_null(port))
831 			nports++;
832 	}
833 
834 	/* Must have DP buffer allocation (multiple USB4 ports) */
835 	if (nports > 2 && (min_dp_aux < 0 || min_dp_main < 0)) {
836 		tb_sw_warn(sw, "multiple USB4 ports require baMinDPaux/baMinDPmain\n");
837 		goto err_invalid;
838 	}
839 
840 	tb_switch_for_each_port(sw, port) {
841 		if (tb_port_is_dpout(port) && min_dp_main < 0) {
842 			tb_sw_warn(sw, "missing baMinDPmain");
843 			goto err_invalid;
844 		}
845 		if ((tb_port_is_dpin(port) || tb_port_is_dpout(port)) &&
846 		    min_dp_aux < 0) {
847 			tb_sw_warn(sw, "missing baMinDPaux");
848 			goto err_invalid;
849 		}
850 		if ((tb_port_is_usb3_down(port) || tb_port_is_usb3_up(port)) &&
851 		    max_usb3 < 0) {
852 			tb_sw_warn(sw, "missing baMaxUSB3");
853 			goto err_invalid;
854 		}
855 		if ((tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) &&
856 		    max_pcie < 0) {
857 			tb_sw_warn(sw, "missing baMaxPCIe");
858 			goto err_invalid;
859 		}
860 	}
861 
862 	/*
863 	 * Buffer allocation passed the validation so we can use it in
864 	 * path creation.
865 	 */
866 	sw->credit_allocation = true;
867 	if (max_usb3 > 0)
868 		sw->max_usb3_credits = max_usb3;
869 	if (min_dp_aux > 0)
870 		sw->min_dp_aux_credits = min_dp_aux;
871 	if (min_dp_main > 0)
872 		sw->min_dp_main_credits = min_dp_main;
873 	if (max_pcie > 0)
874 		sw->max_pcie_credits = max_pcie;
875 	if (max_dma > 0)
876 		sw->max_dma_credits = max_dma;
877 
878 	return 0;
879 
880 err_invalid:
881 	return -EINVAL;
882 }
883 
884 /**
885  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
886  * @sw: USB4 router
887  * @in: DP IN adapter
888  *
889  * For DP tunneling this function can be used to query availability of
890  * DP IN resource.
891  *
892  * Return: %true if the resource is available for DP tunneling, %false
893  * otherwise.
894  */
895 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
896 {
897 	u32 metadata = in->port;
898 	u8 status;
899 	int ret;
900 
901 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
902 			     &status);
903 	/*
904 	 * If DP resource allocation is not supported assume it is
905 	 * always available.
906 	 */
907 	if (ret == -EOPNOTSUPP)
908 		return true;
909 	if (ret)
910 		return false;
911 
912 	return !status;
913 }
914 
915 /**
916  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
917  * @sw: USB4 router
918  * @in: DP IN adapter
919  *
920  * Allocates DP IN resource for DP tunneling using USB4 router
921  * operations.
922  *
923  * Return:
924  * * %0 - Resource allocated successfully.
925  * * %-EBUSY - Resource is already allocated.
926  * * Negative errno - Other failure occurred.
927  */
928 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
929 {
930 	u32 metadata = in->port;
931 	u8 status;
932 	int ret;
933 
934 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
935 			     &status);
936 	if (ret == -EOPNOTSUPP)
937 		return 0;
938 	if (ret)
939 		return ret;
940 
941 	return status ? -EBUSY : 0;
942 }
943 
944 /**
945  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
946  * @sw: USB4 router
947  * @in: DP IN adapter
948  *
949  * Releases the previously allocated DP IN resource.
950  *
951  * Return: %0 on success, negative errno otherwise.
952  */
953 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
954 {
955 	u32 metadata = in->port;
956 	u8 status;
957 	int ret;
958 
959 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
960 			     &status);
961 	if (ret == -EOPNOTSUPP)
962 		return 0;
963 	if (ret)
964 		return ret;
965 
966 	return status ? -EIO : 0;
967 }
968 
969 /**
970  * usb4_port_index() - Finds matching USB4 port index
971  * @sw: USB4 router
972  * @port: USB4 protocol or lane adapter
973  *
974  * Finds matching USB4 port index (starting from %0) that given @port goes
975  * through.
976  */
977 int usb4_port_index(const struct tb_switch *sw, const struct tb_port *port)
978 {
979 	struct tb_port *p;
980 	int usb4_idx = 0;
981 
982 	/* Assume port is primary */
983 	tb_switch_for_each_port(sw, p) {
984 		if (!tb_port_is_null(p))
985 			continue;
986 		if (tb_is_upstream_port(p))
987 			continue;
988 		if (!p->link_nr) {
989 			if (p == port)
990 				break;
991 			usb4_idx++;
992 		}
993 	}
994 
995 	return usb4_idx;
996 }
997 
998 /**
999  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
1000  * @sw: USB4 router
1001  * @port: USB4 port
1002  *
1003  * USB4 routers have direct mapping between USB4 ports and PCIe
1004  * downstream adapters where the PCIe topology is extended. This
1005  * function returns the corresponding downstream PCIe adapter or %NULL
1006  * if no such mapping was possible.
1007  *
1008  * Return: Pointer to &struct tb_port or %NULL if not found.
1009  */
1010 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
1011 					  const struct tb_port *port)
1012 {
1013 	int usb4_idx = usb4_port_index(sw, port);
1014 	struct tb_port *p;
1015 	int pcie_idx = 0;
1016 
1017 	/* Find PCIe down port matching usb4_port */
1018 	tb_switch_for_each_port(sw, p) {
1019 		if (!tb_port_is_pcie_down(p))
1020 			continue;
1021 
1022 		if (pcie_idx == usb4_idx)
1023 			return p;
1024 
1025 		pcie_idx++;
1026 	}
1027 
1028 	return NULL;
1029 }
1030 
1031 /**
1032  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
1033  * @sw: USB4 router
1034  * @port: USB4 port
1035  *
1036  * USB4 routers have direct mapping between USB4 ports and USB 3.x
1037  * downstream adapters where the USB 3.x topology is extended. This
1038  * function returns the corresponding downstream USB 3.x adapter or
1039  * %NULL if no such mapping was possible.
1040  *
1041  * Return: Pointer to &struct tb_port or %NULL if not found.
1042  */
1043 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
1044 					  const struct tb_port *port)
1045 {
1046 	int usb4_idx = usb4_port_index(sw, port);
1047 	struct tb_port *p;
1048 	int usb_idx = 0;
1049 
1050 	/* Find USB3 down port matching usb4_port */
1051 	tb_switch_for_each_port(sw, p) {
1052 		if (!tb_port_is_usb3_down(p))
1053 			continue;
1054 
1055 		if (usb_idx == usb4_idx)
1056 			return p;
1057 
1058 		usb_idx++;
1059 	}
1060 
1061 	return NULL;
1062 }
1063 
1064 /**
1065  * usb4_switch_add_ports() - Add USB4 ports for this router
1066  * @sw: USB4 router
1067  *
1068  * For USB4 router finds all USB4 ports and registers devices for each.
1069  * Can be called to any router.
1070  *
1071  * Return: %0 on success, negative errno otherwise.
1072  */
1073 int usb4_switch_add_ports(struct tb_switch *sw)
1074 {
1075 	struct tb_port *port;
1076 
1077 	if (tb_switch_is_icm(sw) || !tb_switch_is_usb4(sw))
1078 		return 0;
1079 
1080 	tb_switch_for_each_port(sw, port) {
1081 		struct usb4_port *usb4;
1082 
1083 		if (!tb_port_is_null(port))
1084 			continue;
1085 		if (!port->cap_usb4)
1086 			continue;
1087 
1088 		usb4 = usb4_port_device_add(port);
1089 		if (IS_ERR(usb4)) {
1090 			usb4_switch_remove_ports(sw);
1091 			return PTR_ERR(usb4);
1092 		}
1093 
1094 		port->usb4 = usb4;
1095 	}
1096 
1097 	return 0;
1098 }
1099 
1100 /**
1101  * usb4_switch_remove_ports() - Removes USB4 ports from this router
1102  * @sw: USB4 router
1103  *
1104  * Unregisters previously registered USB4 ports.
1105  */
1106 void usb4_switch_remove_ports(struct tb_switch *sw)
1107 {
1108 	struct tb_port *port;
1109 
1110 	tb_switch_for_each_port(sw, port) {
1111 		if (port->usb4) {
1112 			usb4_port_device_remove(port->usb4);
1113 			port->usb4 = NULL;
1114 		}
1115 	}
1116 }
1117 
1118 /**
1119  * usb4_port_unlock() - Unlock USB4 downstream port
1120  * @port: USB4 port to unlock
1121  *
1122  * Unlocks USB4 downstream port so that the connection manager can
1123  * access the router below this port.
1124  *
1125  * Return: %0 on success, negative errno otherwise.
1126  */
1127 int usb4_port_unlock(struct tb_port *port)
1128 {
1129 	int ret;
1130 	u32 val;
1131 
1132 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1133 	if (ret)
1134 		return ret;
1135 
1136 	val &= ~ADP_CS_4_LCK;
1137 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1138 }
1139 
1140 /**
1141  * usb4_port_hotplug_enable() - Enables hotplug for a port
1142  * @port: USB4 port to operate on
1143  *
1144  * Enables hot plug events on a given port. This is only intended
1145  * to be used on lane, DP-IN, and DP-OUT adapters.
1146  *
1147  * Return: %0 on success, negative errno otherwise.
1148  */
1149 int usb4_port_hotplug_enable(struct tb_port *port)
1150 {
1151 	int ret;
1152 	u32 val;
1153 
1154 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1155 	if (ret)
1156 		return ret;
1157 
1158 	val &= ~ADP_CS_5_DHP;
1159 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1160 }
1161 
1162 /**
1163  * usb4_port_reset() - Issue downstream port reset
1164  * @port: USB4 port to reset
1165  *
1166  * Issues downstream port reset to @port.
1167  *
1168  * Return: %0 on success, negative errno otherwise.
1169  */
1170 int usb4_port_reset(struct tb_port *port)
1171 {
1172 	int ret;
1173 	u32 val;
1174 
1175 	if (!port->cap_usb4)
1176 		return -EINVAL;
1177 
1178 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1179 			   port->cap_usb4 + PORT_CS_19, 1);
1180 	if (ret)
1181 		return ret;
1182 
1183 	val |= PORT_CS_19_DPR;
1184 
1185 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1186 			    port->cap_usb4 + PORT_CS_19, 1);
1187 	if (ret)
1188 		return ret;
1189 
1190 	fsleep(10000);
1191 
1192 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1193 			   port->cap_usb4 + PORT_CS_19, 1);
1194 	if (ret)
1195 		return ret;
1196 
1197 	val &= ~PORT_CS_19_DPR;
1198 
1199 	return tb_port_write(port, &val, TB_CFG_PORT,
1200 			     port->cap_usb4 + PORT_CS_19, 1);
1201 }
1202 
1203 static int usb4_port_set_configured(struct tb_port *port, bool configured)
1204 {
1205 	int ret;
1206 	u32 val;
1207 
1208 	if (!port->cap_usb4)
1209 		return -EINVAL;
1210 
1211 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1212 			   port->cap_usb4 + PORT_CS_19, 1);
1213 	if (ret)
1214 		return ret;
1215 
1216 	if (configured)
1217 		val |= PORT_CS_19_PC;
1218 	else
1219 		val &= ~PORT_CS_19_PC;
1220 
1221 	return tb_port_write(port, &val, TB_CFG_PORT,
1222 			     port->cap_usb4 + PORT_CS_19, 1);
1223 }
1224 
1225 /**
1226  * usb4_port_configure() - Set USB4 port configured
1227  * @port: USB4 router
1228  *
1229  * Sets the USB4 link to be configured for power management purposes.
1230  *
1231  * Return: %0 on success, negative errno otherwise.
1232  */
1233 int usb4_port_configure(struct tb_port *port)
1234 {
1235 	return usb4_port_set_configured(port, true);
1236 }
1237 
1238 /**
1239  * usb4_port_unconfigure() - Set USB4 port unconfigured
1240  * @port: USB4 router
1241  *
1242  * Sets the USB4 link to be unconfigured for power management purposes.
1243  *
1244  * Return: %0 on success, negative errno otherwise.
1245  */
1246 void usb4_port_unconfigure(struct tb_port *port)
1247 {
1248 	usb4_port_set_configured(port, false);
1249 }
1250 
1251 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
1252 {
1253 	int ret;
1254 	u32 val;
1255 
1256 	if (!port->cap_usb4)
1257 		return -EINVAL;
1258 
1259 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1260 			   port->cap_usb4 + PORT_CS_19, 1);
1261 	if (ret)
1262 		return ret;
1263 
1264 	if (configured)
1265 		val |= PORT_CS_19_PID;
1266 	else
1267 		val &= ~PORT_CS_19_PID;
1268 
1269 	return tb_port_write(port, &val, TB_CFG_PORT,
1270 			     port->cap_usb4 + PORT_CS_19, 1);
1271 }
1272 
1273 /**
1274  * usb4_port_configure_xdomain() - Configure port for XDomain
1275  * @port: USB4 port connected to another host
1276  * @xd: XDomain that is connected to the port
1277  *
1278  * Marks the USB4 port as being connected to another host and updates
1279  * the link type.
1280  *
1281  * Return: %0 on success, negative errno otherwise.
1282  */
1283 int usb4_port_configure_xdomain(struct tb_port *port, struct tb_xdomain *xd)
1284 {
1285 	xd->link_usb4 = link_is_usb4(port);
1286 	return usb4_set_xdomain_configured(port, true);
1287 }
1288 
1289 /**
1290  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
1291  * @port: USB4 port that was connected to another host
1292  *
1293  * Clears USB4 port from being marked as XDomain.
1294  */
1295 void usb4_port_unconfigure_xdomain(struct tb_port *port)
1296 {
1297 	usb4_set_xdomain_configured(port, false);
1298 }
1299 
1300 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1301 			  u32 value, int timeout_msec, unsigned long delay_usec)
1302 {
1303 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1304 
1305 	do {
1306 		u32 val;
1307 		int ret;
1308 
1309 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1310 		if (ret)
1311 			return ret;
1312 
1313 		if ((val & bit) == value)
1314 			return 0;
1315 
1316 		fsleep(delay_usec);
1317 	} while (ktime_before(ktime_get(), timeout));
1318 
1319 	return -ETIMEDOUT;
1320 }
1321 
1322 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1323 {
1324 	if (dwords > USB4_DATA_DWORDS)
1325 		return -EINVAL;
1326 
1327 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1328 			    dwords);
1329 }
1330 
1331 static int usb4_port_write_data(struct tb_port *port, const void *data,
1332 				size_t dwords)
1333 {
1334 	if (dwords > USB4_DATA_DWORDS)
1335 		return -EINVAL;
1336 
1337 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1338 			     dwords);
1339 }
1340 
1341 /**
1342  * usb4_port_sb_read() - Read from sideband register
1343  * @port: USB4 port to read
1344  * @target: Sideband target
1345  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1346  * @reg: Sideband register index
1347  * @buf: Buffer where the sideband data is copied
1348  * @size: Size of @buf
1349  *
1350  * Reads data from sideband register @reg and copies it into @buf.
1351  *
1352  * Return: %0 on success, negative errno otherwise.
1353  */
1354 int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target, u8 index,
1355 		      u8 reg, void *buf, u8 size)
1356 {
1357 	size_t dwords = DIV_ROUND_UP(size, 4);
1358 	int ret;
1359 	u32 val;
1360 
1361 	if (!port->cap_usb4)
1362 		return -EINVAL;
1363 
1364 	val = reg;
1365 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1366 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1367 	if (target == USB4_SB_TARGET_RETIMER)
1368 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1369 	val |= PORT_CS_1_PND;
1370 
1371 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1372 			    port->cap_usb4 + PORT_CS_1, 1);
1373 	if (ret)
1374 		return ret;
1375 
1376 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1377 				     PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
1378 	if (ret)
1379 		return ret;
1380 
1381 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1382 			    port->cap_usb4 + PORT_CS_1, 1);
1383 	if (ret)
1384 		return ret;
1385 
1386 	if (val & PORT_CS_1_NR)
1387 		return -ENODEV;
1388 	if (val & PORT_CS_1_RC)
1389 		return -EIO;
1390 
1391 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1392 }
1393 
1394 /**
1395  * usb4_port_sb_write() - Write to sideband register
1396  * @port: USB4 port to write
1397  * @target: Sideband target
1398  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1399  * @reg: Sideband register index
1400  * @buf: Data to write
1401  * @size: Size of @buf
1402  *
1403  * Writes @buf to sideband register @reg.
1404  *
1405  * Return: %0 on success, negative errno otherwise.
1406  */
1407 int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1408 		       u8 index, u8 reg, const void *buf, u8 size)
1409 {
1410 	size_t dwords = DIV_ROUND_UP(size, 4);
1411 	int ret;
1412 	u32 val;
1413 
1414 	if (!port->cap_usb4)
1415 		return -EINVAL;
1416 
1417 	if (buf) {
1418 		ret = usb4_port_write_data(port, buf, dwords);
1419 		if (ret)
1420 			return ret;
1421 	}
1422 
1423 	val = reg;
1424 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1425 	val |= PORT_CS_1_WNR_WRITE;
1426 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1427 	if (target == USB4_SB_TARGET_RETIMER)
1428 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1429 	val |= PORT_CS_1_PND;
1430 
1431 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1432 			    port->cap_usb4 + PORT_CS_1, 1);
1433 	if (ret)
1434 		return ret;
1435 
1436 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1437 				     PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
1438 	if (ret)
1439 		return ret;
1440 
1441 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1442 			    port->cap_usb4 + PORT_CS_1, 1);
1443 	if (ret)
1444 		return ret;
1445 
1446 	if (val & PORT_CS_1_NR)
1447 		return -ENODEV;
1448 	if (val & PORT_CS_1_RC)
1449 		return -EIO;
1450 
1451 	return 0;
1452 }
1453 
1454 static int usb4_port_sb_opcode_err_to_errno(u32 val)
1455 {
1456 	switch (val) {
1457 	case 0:
1458 		return 0;
1459 	case USB4_SB_OPCODE_ERR:
1460 		return -EAGAIN;
1461 	case USB4_SB_OPCODE_ONS:
1462 		return -EOPNOTSUPP;
1463 	default:
1464 		return -EIO;
1465 	}
1466 }
1467 
1468 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1469 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1470 {
1471 	ktime_t timeout;
1472 	u32 val;
1473 	int ret;
1474 
1475 	val = opcode;
1476 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1477 				 sizeof(val));
1478 	if (ret)
1479 		return ret;
1480 
1481 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1482 
1483 	do {
1484 		/* Check results */
1485 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1486 					&val, sizeof(val));
1487 		if (ret)
1488 			return ret;
1489 
1490 		if (val != opcode)
1491 			return usb4_port_sb_opcode_err_to_errno(val);
1492 
1493 		fsleep(USB4_PORT_SB_DELAY);
1494 	} while (ktime_before(ktime_get(), timeout));
1495 
1496 	return -ETIMEDOUT;
1497 }
1498 
1499 static int usb4_port_set_router_offline(struct tb_port *port, bool offline)
1500 {
1501 	u32 val = !offline;
1502 	int ret;
1503 
1504 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1505 				  USB4_SB_METADATA, &val, sizeof(val));
1506 	if (ret)
1507 		return ret;
1508 
1509 	val = USB4_SB_OPCODE_ROUTER_OFFLINE;
1510 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1511 				  USB4_SB_OPCODE, &val, sizeof(val));
1512 }
1513 
1514 /**
1515  * usb4_port_router_offline() - Put the USB4 port to offline mode
1516  * @port: USB4 port
1517  *
1518  * This function puts the USB4 port into offline mode. In this mode the
1519  * port does not react on hotplug events anymore. This needs to be
1520  * called before retimer access is done when the USB4 links is not up.
1521  *
1522  * Return: %0 on success, negative errno otherwise.
1523  */
1524 int usb4_port_router_offline(struct tb_port *port)
1525 {
1526 	return usb4_port_set_router_offline(port, true);
1527 }
1528 
1529 /**
1530  * usb4_port_router_online() - Put the USB4 port back to online
1531  * @port: USB4 port
1532  *
1533  * Makes the USB4 port functional again.
1534  *
1535  * Return: %0 on success, negative errno otherwise.
1536  */
1537 int usb4_port_router_online(struct tb_port *port)
1538 {
1539 	return usb4_port_set_router_offline(port, false);
1540 }
1541 
1542 /**
1543  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1544  * @port: USB4 port
1545  *
1546  * This forces the USB4 port to send broadcast RT transaction which
1547  * makes the retimers on the link assign index to themselves.
1548  *
1549  * Return: %0 on success, negative errno otherwise.
1550  */
1551 int usb4_port_enumerate_retimers(struct tb_port *port)
1552 {
1553 	u32 val;
1554 
1555 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1556 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1557 				  USB4_SB_OPCODE, &val, sizeof(val));
1558 }
1559 
1560 /**
1561  * usb4_port_clx_supported() - Check if CLx is supported by the link
1562  * @port: Port to check for CLx support for
1563  *
1564  * PORT_CS_18_CPS bit reflects if the link supports CLx including
1565  * active cables (if connected on the link).
1566  *
1567  * Return: %true if Clx is supported, %false otherwise.
1568  */
1569 bool usb4_port_clx_supported(struct tb_port *port)
1570 {
1571 	int ret;
1572 	u32 val;
1573 
1574 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1575 			   port->cap_usb4 + PORT_CS_18, 1);
1576 	if (ret)
1577 		return false;
1578 
1579 	return !!(val & PORT_CS_18_CPS);
1580 }
1581 
1582 /**
1583  * usb4_port_asym_supported() - If the port supports asymmetric link
1584  * @port: USB4 port
1585  *
1586  * Checks if the port and the cable support asymmetric link.
1587  *
1588  * Return: %true if asymmetric link is supported, %false otherwise.
1589  */
1590 bool usb4_port_asym_supported(struct tb_port *port)
1591 {
1592 	u32 val;
1593 
1594 	if (!port->cap_usb4)
1595 		return false;
1596 
1597 	if (tb_port_read(port, &val, TB_CFG_PORT, port->cap_usb4 + PORT_CS_18, 1))
1598 		return false;
1599 
1600 	return !!(val & PORT_CS_18_CSA);
1601 }
1602 
1603 /**
1604  * usb4_port_asym_set_link_width() - Set link width to asymmetric or symmetric
1605  * @port: USB4 port
1606  * @width: Asymmetric width to configure
1607  *
1608  * Sets USB4 port link width to @width. Can be called for widths where
1609  * usb4_port_asym_width_supported() returned @true.
1610  *
1611  * Return: %0 on success, negative errno otherwise.
1612  */
1613 int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width)
1614 {
1615 	u32 val;
1616 	int ret;
1617 
1618 	if (!port->cap_phy)
1619 		return -EINVAL;
1620 
1621 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1622 			   port->cap_phy + LANE_ADP_CS_1, 1);
1623 	if (ret)
1624 		return ret;
1625 
1626 	val &= ~LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK;
1627 	switch (width) {
1628 	case TB_LINK_WIDTH_DUAL:
1629 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1630 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_DUAL);
1631 		break;
1632 	case TB_LINK_WIDTH_ASYM_TX:
1633 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1634 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_TX);
1635 		break;
1636 	case TB_LINK_WIDTH_ASYM_RX:
1637 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1638 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_RX);
1639 		break;
1640 	default:
1641 		return -EINVAL;
1642 	}
1643 
1644 	return tb_port_write(port, &val, TB_CFG_PORT,
1645 			     port->cap_phy + LANE_ADP_CS_1, 1);
1646 }
1647 
1648 /**
1649  * usb4_port_asym_start() - Start symmetry change and wait for completion
1650  * @port: USB4 port
1651  *
1652  * Start symmetry change of the link to asymmetric or symmetric
1653  * (according to what was previously set in tb_port_set_link_width().
1654  * Wait for completion of the change.
1655  *
1656  * Return:
1657  * * %0 - Symmetry change was successful.
1658  * * %-ETIMEDOUT - Timeout occurred.
1659  * * Negative errno - Other failure occurred.
1660  */
1661 int usb4_port_asym_start(struct tb_port *port)
1662 {
1663 	int ret;
1664 	u32 val;
1665 
1666 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1667 			   port->cap_usb4 + PORT_CS_19, 1);
1668 	if (ret)
1669 		return ret;
1670 
1671 	val &= ~PORT_CS_19_START_ASYM;
1672 	val |= FIELD_PREP(PORT_CS_19_START_ASYM, 1);
1673 
1674 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1675 			    port->cap_usb4 + PORT_CS_19, 1);
1676 	if (ret)
1677 		return ret;
1678 
1679 	/*
1680 	 * Wait for PORT_CS_19_START_ASYM to be 0. This means the USB4
1681 	 * port started the symmetry transition.
1682 	 */
1683 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_19,
1684 				     PORT_CS_19_START_ASYM, 0, 1000,
1685 				     USB4_PORT_DELAY);
1686 	if (ret)
1687 		return ret;
1688 
1689 	/* Then wait for the transtion to be completed */
1690 	return usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_18,
1691 				      PORT_CS_18_TIP, 0, 5000, USB4_PORT_DELAY);
1692 }
1693 
1694 /**
1695  * usb4_port_margining_caps() - Read USB4 port marginig capabilities
1696  * @port: USB4 port
1697  * @target: Sideband target
1698  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1699  * @caps: Array with at least two elements to hold the results
1700  * @ncaps: Number of elements in the caps array
1701  *
1702  * Reads the USB4 port lane margining capabilities into @caps.
1703  *
1704  * Return: %0 on success, negative errno otherwise.
1705  */
1706 int usb4_port_margining_caps(struct tb_port *port, enum usb4_sb_target target,
1707 			     u8 index, u32 *caps, size_t ncaps)
1708 {
1709 	int ret;
1710 
1711 	ret = usb4_port_sb_op(port, target, index,
1712 			      USB4_SB_OPCODE_READ_LANE_MARGINING_CAP, 500);
1713 	if (ret)
1714 		return ret;
1715 
1716 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, caps,
1717 				 sizeof(*caps) * ncaps);
1718 }
1719 
1720 /**
1721  * usb4_port_hw_margin() - Run hardware lane margining on port
1722  * @port: USB4 port
1723  * @target: Sideband target
1724  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1725  * @params: Parameters for USB4 hardware margining
1726  * @results: Array to hold the results
1727  * @nresults: Number of elements in the results array
1728  *
1729  * Runs hardware lane margining on USB4 port and returns the result in
1730  * @results.
1731  *
1732  * Return: %0 on success, negative errno otherwise.
1733  */
1734 int usb4_port_hw_margin(struct tb_port *port, enum usb4_sb_target target,
1735 			u8 index, const struct usb4_port_margining_params *params,
1736 			u32 *results, size_t nresults)
1737 {
1738 	u32 val;
1739 	int ret;
1740 
1741 	if (WARN_ON_ONCE(!params))
1742 		return -EINVAL;
1743 
1744 	val = params->lanes;
1745 	if (params->time)
1746 		val |= USB4_MARGIN_HW_TIME;
1747 	if (params->right_high || params->upper_eye)
1748 		val |= USB4_MARGIN_HW_RHU;
1749 	if (params->ber_level)
1750 		val |= FIELD_PREP(USB4_MARGIN_HW_BER_MASK, params->ber_level);
1751 	if (params->optional_voltage_offset_range)
1752 		val |= USB4_MARGIN_HW_OPT_VOLTAGE;
1753 
1754 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1755 				 sizeof(val));
1756 	if (ret)
1757 		return ret;
1758 
1759 	ret = usb4_port_sb_op(port, target, index,
1760 			      USB4_SB_OPCODE_RUN_HW_LANE_MARGINING, 2500);
1761 	if (ret)
1762 		return ret;
1763 
1764 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, results,
1765 				 sizeof(*results) * nresults);
1766 }
1767 
1768 /**
1769  * usb4_port_sw_margin() - Run software lane margining on port
1770  * @port: USB4 port
1771  * @target: Sideband target
1772  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1773  * @params: Parameters for USB4 software margining
1774  * @results: Data word for the operation completion data
1775  *
1776  * Runs software lane margining on USB4 port. Read back the error
1777  * counters by calling usb4_port_sw_margin_errors().
1778  *
1779  * Return: %0 on success, negative errno otherwise.
1780  */
1781 int usb4_port_sw_margin(struct tb_port *port, enum usb4_sb_target target,
1782 			u8 index, const struct usb4_port_margining_params *params,
1783 			u32 *results)
1784 {
1785 	u32 val;
1786 	int ret;
1787 
1788 	if (WARN_ON_ONCE(!params))
1789 		return -EINVAL;
1790 
1791 	val = params->lanes;
1792 	if (params->time)
1793 		val |= USB4_MARGIN_SW_TIME;
1794 	if (params->optional_voltage_offset_range)
1795 		val |= USB4_MARGIN_SW_OPT_VOLTAGE;
1796 	if (params->right_high)
1797 		val |= USB4_MARGIN_SW_RH;
1798 	if (params->upper_eye)
1799 		val |= USB4_MARGIN_SW_UPPER_EYE;
1800 	val |= FIELD_PREP(USB4_MARGIN_SW_COUNTER_MASK, params->error_counter);
1801 	val |= FIELD_PREP(USB4_MARGIN_SW_VT_MASK, params->voltage_time_offset);
1802 
1803 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1804 				 sizeof(val));
1805 	if (ret)
1806 		return ret;
1807 
1808 	ret = usb4_port_sb_op(port, target, index,
1809 			      USB4_SB_OPCODE_RUN_SW_LANE_MARGINING, 2500);
1810 	if (ret)
1811 		return ret;
1812 
1813 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, results,
1814 				 sizeof(*results));
1815 
1816 }
1817 
1818 /**
1819  * usb4_port_sw_margin_errors() - Read the software margining error counters
1820  * @port: USB4 port
1821  * @target: Sideband target
1822  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1823  * @errors: Error metadata is copied here.
1824  *
1825  * This reads back the software margining error counters from the port.
1826  *
1827  * Return: %0 on success, negative errno otherwise.
1828  */
1829 int usb4_port_sw_margin_errors(struct tb_port *port, enum usb4_sb_target target,
1830 			       u8 index, u32 *errors)
1831 {
1832 	int ret;
1833 
1834 	ret = usb4_port_sb_op(port, target, index,
1835 			      USB4_SB_OPCODE_READ_SW_MARGIN_ERR, 150);
1836 	if (ret)
1837 		return ret;
1838 
1839 	return usb4_port_sb_read(port, target, index, USB4_SB_METADATA, errors,
1840 				 sizeof(*errors));
1841 }
1842 
1843 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1844 				       enum usb4_sb_opcode opcode,
1845 				       int timeout_msec)
1846 {
1847 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1848 			       timeout_msec);
1849 }
1850 
1851 /**
1852  * usb4_port_retimer_set_inbound_sbtx() - Enable sideband channel transactions
1853  * @port: USB4 port
1854  * @index: Retimer index
1855  *
1856  * Enables sideband channel transations on SBTX. Can be used when USB4
1857  * link does not go up, for example if there is no device connected.
1858  *
1859  * Return: %0 on success, negative errno otherwise.
1860  */
1861 int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
1862 {
1863 	int ret;
1864 
1865 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1866 				   500);
1867 
1868 	if (ret != -ENODEV)
1869 		return ret;
1870 
1871 	/*
1872 	 * Per the USB4 retimer spec, the retimer is not required to
1873 	 * send an RT (Retimer Transaction) response for the first
1874 	 * SET_INBOUND_SBTX command
1875 	 */
1876 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1877 				    500);
1878 }
1879 
1880 /**
1881  * usb4_port_retimer_unset_inbound_sbtx() - Disable sideband channel transactions
1882  * @port: USB4 port
1883  * @index: Retimer index
1884  *
1885  * Disables sideband channel transations on SBTX. The reverse of
1886  * usb4_port_retimer_set_inbound_sbtx().
1887  *
1888  * Return: %0 on success, negative errno otherwise.
1889  */
1890 int usb4_port_retimer_unset_inbound_sbtx(struct tb_port *port, u8 index)
1891 {
1892 	return usb4_port_retimer_op(port, index,
1893 				    USB4_SB_OPCODE_UNSET_INBOUND_SBTX, 500);
1894 }
1895 
1896 /**
1897  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1898  * @port: USB4 port
1899  * @index: Retimer index
1900  *
1901  * Return:
1902  * * %1 - Retimer at @index is the last one (connected directly to the
1903  *   Type-C port).
1904  * * %0 - Retimer at @index is not the last one.
1905  * * %-ENODEV - Retimer is not present.
1906  * * Negative errno - Other failure occurred.
1907  */
1908 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1909 {
1910 	u32 metadata;
1911 	int ret;
1912 
1913 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1914 				   500);
1915 	if (ret)
1916 		return ret;
1917 
1918 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1919 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1920 	return ret ? ret : metadata & 1;
1921 }
1922 
1923 /**
1924  * usb4_port_retimer_is_cable() - Is the retimer cable retimer
1925  * @port: USB4 port
1926  * @index: Retimer index
1927  *
1928  * Return:
1929  * * %1 - Retimer at @index is the last cable retimer.
1930  * * %0 - Retimer at @index is on-board retimer.
1931  * * %-ENODEV - Retimer is not present.
1932  * * Negative errno - Other failure occurred.
1933  */
1934 int usb4_port_retimer_is_cable(struct tb_port *port, u8 index)
1935 {
1936 	u32 metadata;
1937 	int ret;
1938 
1939 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_CABLE_RETIMER,
1940 				   500);
1941 	if (ret)
1942 		return ret;
1943 
1944 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1945 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1946 	return ret ? ret : metadata & 1;
1947 }
1948 
1949 /**
1950  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1951  * @port: USB4 port
1952  * @index: Retimer index
1953  *
1954  * Reads NVM sector size (in bytes) of a retimer at @index. This
1955  * operation can be used to determine whether the retimer supports NVM
1956  * upgrade for example.
1957  *
1958  * Return:
1959  * * Sector size in bytes.
1960  * * %-ENODEV - If there is no retimer at @index.
1961  * * Negative errno - In case of an error.
1962  */
1963 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1964 {
1965 	u32 metadata;
1966 	int ret;
1967 
1968 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1969 				   500);
1970 	if (ret)
1971 		return ret;
1972 
1973 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1974 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1975 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1976 }
1977 
1978 /**
1979  * usb4_port_retimer_nvm_set_offset() - Set NVM write offset
1980  * @port: USB4 port
1981  * @index: Retimer index
1982  * @address: Start offset
1983  *
1984  * Exlicitly sets NVM write offset. Normally when writing to NVM this is
1985  * done automatically by usb4_port_retimer_nvm_write().
1986  *
1987  * Return: %0 on success, negative errno otherwise.
1988  */
1989 int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1990 				     unsigned int address)
1991 {
1992 	u32 metadata, dwaddress;
1993 	int ret;
1994 
1995 	dwaddress = address / 4;
1996 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1997 		  USB4_NVM_SET_OFFSET_MASK;
1998 
1999 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2000 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
2001 	if (ret)
2002 		return ret;
2003 
2004 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
2005 				    500);
2006 }
2007 
2008 struct retimer_info {
2009 	struct tb_port *port;
2010 	u8 index;
2011 };
2012 
2013 static int usb4_port_retimer_nvm_write_next_block(void *data,
2014 	unsigned int dwaddress, const void *buf, size_t dwords)
2015 
2016 {
2017 	const struct retimer_info *info = data;
2018 	struct tb_port *port = info->port;
2019 	u8 index = info->index;
2020 	int ret;
2021 
2022 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2023 				 USB4_SB_DATA, buf, dwords * 4);
2024 	if (ret)
2025 		return ret;
2026 
2027 	return usb4_port_retimer_op(port, index,
2028 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
2029 }
2030 
2031 /**
2032  * usb4_port_retimer_nvm_write() - Write to retimer NVM
2033  * @port: USB4 port
2034  * @index: Retimer index
2035  * @address: Byte address where to start the write
2036  * @buf: Data to write
2037  * @size: Size in bytes how much to write
2038  *
2039  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
2040  * upgrade.
2041  *
2042  * Return:
2043  * * %0 - If the data was written successfully.
2044  * * %-ENODEV - If there is no retimer at @index.
2045  * * Negative errno - In case of an error.
2046  */
2047 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
2048 				const void *buf, size_t size)
2049 {
2050 	struct retimer_info info = { .port = port, .index = index };
2051 	int ret;
2052 
2053 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
2054 	if (ret)
2055 		return ret;
2056 
2057 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
2058 				 usb4_port_retimer_nvm_write_next_block, &info);
2059 }
2060 
2061 /**
2062  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
2063  * @port: USB4 port
2064  * @index: Retimer index
2065  *
2066  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
2067  * this function can be used to trigger the NVM upgrade process. If
2068  * successful the retimer restarts with the new NVM and may not have the
2069  * index set so one needs to call usb4_port_enumerate_retimers() to
2070  * force index to be assigned.
2071  *
2072  * Return: %0 on success, negative errno otherwise.
2073  */
2074 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
2075 {
2076 	u32 val;
2077 
2078 	/*
2079 	 * We need to use the raw operation here because once the
2080 	 * authentication completes the retimer index is not set anymore
2081 	 * so we do not get back the status now.
2082 	 */
2083 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
2084 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2085 				  USB4_SB_OPCODE, &val, sizeof(val));
2086 }
2087 
2088 /**
2089  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
2090  * @port: USB4 port
2091  * @index: Retimer index
2092  * @status: Raw status code read from metadata
2093  *
2094  * This can be called after usb4_port_retimer_nvm_authenticate() and
2095  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
2096  *
2097  * Return: %0 if the authentication status was successfully read. The
2098  * completion metadata (the result) is then stored into @status. If
2099  * status read fails, returns negative errno.
2100  */
2101 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
2102 					      u32 *status)
2103 {
2104 	u32 metadata, val;
2105 	int ret;
2106 
2107 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2108 				USB4_SB_OPCODE, &val, sizeof(val));
2109 	if (ret)
2110 		return ret;
2111 
2112 	ret = usb4_port_sb_opcode_err_to_errno(val);
2113 	switch (ret) {
2114 	case 0:
2115 		*status = 0;
2116 		return 0;
2117 
2118 	case -EAGAIN:
2119 		ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2120 					USB4_SB_METADATA, &metadata,
2121 					sizeof(metadata));
2122 		if (ret)
2123 			return ret;
2124 
2125 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
2126 		return 0;
2127 
2128 	default:
2129 		return ret;
2130 	}
2131 }
2132 
2133 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
2134 					    void *buf, size_t dwords)
2135 {
2136 	const struct retimer_info *info = data;
2137 	struct tb_port *port = info->port;
2138 	u8 index = info->index;
2139 	u32 metadata;
2140 	int ret;
2141 
2142 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
2143 	if (dwords < USB4_DATA_DWORDS)
2144 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
2145 
2146 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2147 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
2148 	if (ret)
2149 		return ret;
2150 
2151 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
2152 	if (ret)
2153 		return ret;
2154 
2155 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2156 				 USB4_SB_DATA, buf, dwords * 4);
2157 }
2158 
2159 /**
2160  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
2161  * @port: USB4 port
2162  * @index: Retimer index
2163  * @address: NVM address (in bytes) to start reading
2164  * @buf: Data read from NVM is stored here
2165  * @size: Number of bytes to read
2166  *
2167  * Reads retimer NVM and copies the contents to @buf.
2168  *
2169  * Return:
2170  * * %0 - If the read was successful.
2171  * * %-ENODEV - If there is no retimer at @index.
2172  * * Negative errno - In case of an error.
2173  */
2174 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
2175 			       unsigned int address, void *buf, size_t size)
2176 {
2177 	struct retimer_info info = { .port = port, .index = index };
2178 
2179 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
2180 				usb4_port_retimer_nvm_read_block, &info);
2181 }
2182 
2183 static inline unsigned int
2184 usb4_usb3_port_max_bandwidth(const struct tb_port *port, unsigned int bw)
2185 {
2186 	/* Take the possible bandwidth limitation into account */
2187 	if (port->max_bw)
2188 		return min(bw, port->max_bw);
2189 	return bw;
2190 }
2191 
2192 /**
2193  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
2194  * @port: USB3 adapter port
2195  *
2196  * Return: Maximum supported link rate of a USB3 adapter in Mb/s.
2197  * Negative errno in case of an error.
2198  */
2199 int usb4_usb3_port_max_link_rate(struct tb_port *port)
2200 {
2201 	int ret, lr;
2202 	u32 val;
2203 
2204 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
2205 		return -EINVAL;
2206 
2207 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2208 			   port->cap_adap + ADP_USB3_CS_4, 1);
2209 	if (ret)
2210 		return ret;
2211 
2212 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
2213 	ret = lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
2214 
2215 	return usb4_usb3_port_max_bandwidth(port, ret);
2216 }
2217 
2218 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
2219 {
2220 	int ret;
2221 	u32 val;
2222 
2223 	if (!tb_port_is_usb3_down(port))
2224 		return -EINVAL;
2225 	if (tb_route(port->sw))
2226 		return -EINVAL;
2227 
2228 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2229 			   port->cap_adap + ADP_USB3_CS_2, 1);
2230 	if (ret)
2231 		return ret;
2232 
2233 	if (request)
2234 		val |= ADP_USB3_CS_2_CMR;
2235 	else
2236 		val &= ~ADP_USB3_CS_2_CMR;
2237 
2238 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2239 			    port->cap_adap + ADP_USB3_CS_2, 1);
2240 	if (ret)
2241 		return ret;
2242 
2243 	/*
2244 	 * We can use val here directly as the CMR bit is in the same place
2245 	 * as HCA. Just mask out others.
2246 	 */
2247 	val &= ADP_USB3_CS_2_CMR;
2248 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
2249 				      ADP_USB3_CS_1_HCA, val, 1500,
2250 				      USB4_PORT_DELAY);
2251 }
2252 
2253 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
2254 {
2255 	return usb4_usb3_port_cm_request(port, true);
2256 }
2257 
2258 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
2259 {
2260 	return usb4_usb3_port_cm_request(port, false);
2261 }
2262 
2263 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
2264 {
2265 	unsigned long uframes;
2266 
2267 	uframes = bw * 512UL << scale;
2268 	return DIV_ROUND_CLOSEST(uframes * 8000, MEGA);
2269 }
2270 
2271 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
2272 {
2273 	unsigned long uframes;
2274 
2275 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
2276 	uframes = ((unsigned long)mbps * MEGA) / 8000;
2277 	return DIV_ROUND_UP(uframes, 512UL << scale);
2278 }
2279 
2280 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
2281 						   int *upstream_bw,
2282 						   int *downstream_bw)
2283 {
2284 	u32 val, bw, scale;
2285 	int ret;
2286 
2287 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2288 			   port->cap_adap + ADP_USB3_CS_2, 1);
2289 	if (ret)
2290 		return ret;
2291 
2292 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2293 			   port->cap_adap + ADP_USB3_CS_3, 1);
2294 	if (ret)
2295 		return ret;
2296 
2297 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2298 
2299 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
2300 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2301 
2302 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
2303 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2304 
2305 	return 0;
2306 }
2307 
2308 /**
2309  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
2310  * @port: USB3 adapter port
2311  * @upstream_bw: Allocated upstream bandwidth is stored here
2312  * @downstream_bw: Allocated downstream bandwidth is stored here
2313  *
2314  * Stores currently allocated USB3 bandwidth into @upstream_bw and
2315  * @downstream_bw in Mb/s.
2316  *
2317  * Return: %0 on success, negative errno otherwise.
2318  */
2319 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
2320 				       int *downstream_bw)
2321 {
2322 	int ret;
2323 
2324 	ret = usb4_usb3_port_set_cm_request(port);
2325 	if (ret)
2326 		return ret;
2327 
2328 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
2329 						      downstream_bw);
2330 	usb4_usb3_port_clear_cm_request(port);
2331 
2332 	return ret;
2333 }
2334 
2335 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
2336 						  int *upstream_bw,
2337 						  int *downstream_bw)
2338 {
2339 	u32 val, bw, scale;
2340 	int ret;
2341 
2342 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2343 			   port->cap_adap + ADP_USB3_CS_1, 1);
2344 	if (ret)
2345 		return ret;
2346 
2347 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2348 			   port->cap_adap + ADP_USB3_CS_3, 1);
2349 	if (ret)
2350 		return ret;
2351 
2352 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2353 
2354 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
2355 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2356 
2357 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
2358 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2359 
2360 	return 0;
2361 }
2362 
2363 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
2364 						    int upstream_bw,
2365 						    int downstream_bw)
2366 {
2367 	u32 val, ubw, dbw, scale;
2368 	int ret, max_bw;
2369 
2370 	/* Figure out suitable scale */
2371 	scale = 0;
2372 	max_bw = max(upstream_bw, downstream_bw);
2373 	while (scale < 64) {
2374 		if (mbps_to_usb3_bw(max_bw, scale) < 4096)
2375 			break;
2376 		scale++;
2377 	}
2378 
2379 	if (WARN_ON(scale >= 64))
2380 		return -EINVAL;
2381 
2382 	ret = tb_port_write(port, &scale, TB_CFG_PORT,
2383 			    port->cap_adap + ADP_USB3_CS_3, 1);
2384 	if (ret)
2385 		return ret;
2386 
2387 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
2388 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
2389 
2390 	tb_port_dbg(port, "scaled bandwidth %u/%u, scale %u\n", ubw, dbw, scale);
2391 
2392 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2393 			   port->cap_adap + ADP_USB3_CS_2, 1);
2394 	if (ret)
2395 		return ret;
2396 
2397 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
2398 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
2399 	val |= ubw;
2400 
2401 	return tb_port_write(port, &val, TB_CFG_PORT,
2402 			     port->cap_adap + ADP_USB3_CS_2, 1);
2403 }
2404 
2405 /**
2406  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
2407  * @port: USB3 adapter port
2408  * @upstream_bw: New upstream bandwidth
2409  * @downstream_bw: New downstream bandwidth
2410  *
2411  * This can be used to set how much bandwidth is allocated for the USB3
2412  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
2413  * new values programmed to the USB3 adapter allocation registers. If
2414  * the values are lower than what is currently consumed the allocation
2415  * is set to what is currently consumed instead (consumed bandwidth
2416  * cannot be taken away by CM). The actual new values are returned in
2417  * @upstream_bw and @downstream_bw.
2418  *
2419  * Return: %0 on success, negative errno otherwise.
2420  */
2421 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
2422 				      int *downstream_bw)
2423 {
2424 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
2425 
2426 	ret = usb4_usb3_port_set_cm_request(port);
2427 	if (ret)
2428 		return ret;
2429 
2430 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2431 						     &consumed_down);
2432 	if (ret)
2433 		goto err_request;
2434 
2435 	/* Don't allow it go lower than what is consumed */
2436 	allocate_up = max(*upstream_bw, consumed_up);
2437 	allocate_down = max(*downstream_bw, consumed_down);
2438 
2439 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
2440 						       allocate_down);
2441 	if (ret)
2442 		goto err_request;
2443 
2444 	*upstream_bw = allocate_up;
2445 	*downstream_bw = allocate_down;
2446 
2447 err_request:
2448 	usb4_usb3_port_clear_cm_request(port);
2449 	return ret;
2450 }
2451 
2452 /**
2453  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
2454  * @port: USB3 adapter port
2455  * @upstream_bw: New allocated upstream bandwidth
2456  * @downstream_bw: New allocated downstream bandwidth
2457  *
2458  * Releases USB3 allocated bandwidth down to what is actually consumed.
2459  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
2460  *
2461  * Return: %0 on success, negative errno otherwise.
2462  */
2463 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
2464 				     int *downstream_bw)
2465 {
2466 	int ret, consumed_up, consumed_down;
2467 
2468 	ret = usb4_usb3_port_set_cm_request(port);
2469 	if (ret)
2470 		return ret;
2471 
2472 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2473 						     &consumed_down);
2474 	if (ret)
2475 		goto err_request;
2476 
2477 	/*
2478 	 * Always keep 900 Mb/s to make sure xHCI has at least some
2479 	 * bandwidth available for isochronous traffic.
2480 	 */
2481 	if (consumed_up < 900)
2482 		consumed_up = 900;
2483 	if (consumed_down < 900)
2484 		consumed_down = 900;
2485 
2486 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
2487 						       consumed_down);
2488 	if (ret)
2489 		goto err_request;
2490 
2491 	*upstream_bw = consumed_up;
2492 	*downstream_bw = consumed_down;
2493 
2494 err_request:
2495 	usb4_usb3_port_clear_cm_request(port);
2496 	return ret;
2497 }
2498 
2499 static bool is_usb4_dpin(const struct tb_port *port)
2500 {
2501 	if (!tb_port_is_dpin(port))
2502 		return false;
2503 	if (!tb_switch_is_usb4(port->sw))
2504 		return false;
2505 	return true;
2506 }
2507 
2508 /**
2509  * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
2510  * @port: DP IN adapter
2511  * @cm_id: CM ID to assign
2512  *
2513  * Sets CM ID for the @port.
2514  *
2515  * Return:
2516  * * %0 - On success.
2517  * * %-EOPNOTSUPP - If the @port does not support this.
2518  * * Negative errno - Another error occurred.
2519  */
2520 int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
2521 {
2522 	u32 val;
2523 	int ret;
2524 
2525 	if (!is_usb4_dpin(port))
2526 		return -EOPNOTSUPP;
2527 
2528 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2529 			   port->cap_adap + ADP_DP_CS_2, 1);
2530 	if (ret)
2531 		return ret;
2532 
2533 	val &= ~ADP_DP_CS_2_CM_ID_MASK;
2534 	val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
2535 
2536 	return tb_port_write(port, &val, TB_CFG_PORT,
2537 			     port->cap_adap + ADP_DP_CS_2, 1);
2538 }
2539 
2540 /**
2541  * usb4_dp_port_bandwidth_mode_supported() - Is the bandwidth allocation mode
2542  *					     supported
2543  * @port: DP IN adapter to check
2544  *
2545  * Can be called to any DP IN adapter.
2546  *
2547  * Return: %true if the adapter supports USB4 bandwidth allocation mode,
2548  * %false otherwise.
2549  */
2550 bool usb4_dp_port_bandwidth_mode_supported(struct tb_port *port)
2551 {
2552 	int ret;
2553 	u32 val;
2554 
2555 	if (!is_usb4_dpin(port))
2556 		return false;
2557 
2558 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2559 			   port->cap_adap + DP_LOCAL_CAP, 1);
2560 	if (ret)
2561 		return false;
2562 
2563 	return !!(val & DP_COMMON_CAP_BW_MODE);
2564 }
2565 
2566 /**
2567  * usb4_dp_port_bandwidth_mode_enabled() - Is the bandwidth allocation mode
2568  *					   enabled
2569  * @port: DP IN adapter to check
2570  *
2571  * Can be called to any DP IN adapter.
2572  *
2573  * Return: %true if the bandwidth allocation mode has been enabled,
2574  * %false otherwise.
2575  */
2576 bool usb4_dp_port_bandwidth_mode_enabled(struct tb_port *port)
2577 {
2578 	int ret;
2579 	u32 val;
2580 
2581 	if (!is_usb4_dpin(port))
2582 		return false;
2583 
2584 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2585 			   port->cap_adap + ADP_DP_CS_8, 1);
2586 	if (ret)
2587 		return false;
2588 
2589 	return !!(val & ADP_DP_CS_8_DPME);
2590 }
2591 
2592 /**
2593  * usb4_dp_port_set_cm_bandwidth_mode_supported() - Set/clear CM support for
2594  *						    bandwidth allocation mode
2595  * @port: DP IN adapter
2596  * @supported: Does the CM support bandwidth allocation mode
2597  *
2598  * Can be called to any DP IN adapter. Sets or clears the CM support bit
2599  * of the DP IN adapter.
2600  *
2601  * * Return:
2602  * * %0 - On success.
2603  * * %-EOPNOTSUPP - If the passed IN adapter does not support this.
2604  * * Negative errno - Another error occurred.
2605  */
2606 int usb4_dp_port_set_cm_bandwidth_mode_supported(struct tb_port *port,
2607 						 bool supported)
2608 {
2609 	u32 val;
2610 	int ret;
2611 
2612 	if (!is_usb4_dpin(port))
2613 		return -EOPNOTSUPP;
2614 
2615 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2616 			   port->cap_adap + ADP_DP_CS_2, 1);
2617 	if (ret)
2618 		return ret;
2619 
2620 	if (supported)
2621 		val |= ADP_DP_CS_2_CMMS;
2622 	else
2623 		val &= ~ADP_DP_CS_2_CMMS;
2624 
2625 	return tb_port_write(port, &val, TB_CFG_PORT,
2626 			     port->cap_adap + ADP_DP_CS_2, 1);
2627 }
2628 
2629 /**
2630  * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
2631  * @port: DP IN adapter
2632  *
2633  * Reads bandwidth allocation Group ID from the DP IN adapter and
2634  * returns it.
2635  *
2636  * Return:
2637  * * Group ID assigned to adapter @port.
2638  * * %-EOPNOTSUPP - If adapter does not support setting GROUP_ID.
2639  * * Negative errno - Another error occurred.
2640  */
2641 int usb4_dp_port_group_id(struct tb_port *port)
2642 {
2643 	u32 val;
2644 	int ret;
2645 
2646 	if (!is_usb4_dpin(port))
2647 		return -EOPNOTSUPP;
2648 
2649 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2650 			   port->cap_adap + ADP_DP_CS_2, 1);
2651 	if (ret)
2652 		return ret;
2653 
2654 	return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
2655 }
2656 
2657 /**
2658  * usb4_dp_port_set_group_id() - Set adapter Group ID
2659  * @port: DP IN adapter
2660  * @group_id: Group ID for the adapter
2661  *
2662  * Sets bandwidth allocation mode Group ID for the DP IN adapter.
2663  *
2664  * Return:
2665  * * %0 - On success.
2666  * * %-EOPNOTSUPP - If the adapter does not support this.
2667  * * Negative errno - Another error occurred.
2668  */
2669 int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
2670 {
2671 	u32 val;
2672 	int ret;
2673 
2674 	if (!is_usb4_dpin(port))
2675 		return -EOPNOTSUPP;
2676 
2677 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2678 			   port->cap_adap + ADP_DP_CS_2, 1);
2679 	if (ret)
2680 		return ret;
2681 
2682 	val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
2683 	val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
2684 
2685 	return tb_port_write(port, &val, TB_CFG_PORT,
2686 			     port->cap_adap + ADP_DP_CS_2, 1);
2687 }
2688 
2689 /**
2690  * usb4_dp_port_nrd() - Read non-reduced rate and lanes
2691  * @port: DP IN adapter
2692  * @rate: Non-reduced rate in Mb/s is placed here
2693  * @lanes: Non-reduced lanes are placed here
2694  *
2695  * Reads the non-reduced rate and lanes from the DP IN adapter.
2696  *
2697  * Return:
2698  * * %0 - On success.
2699  * * %-EOPNOTSUPP - If the adapter does not support this.
2700  * * Negative errno - Another error occurred.
2701  */
2702 int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
2703 {
2704 	u32 val, tmp;
2705 	int ret;
2706 
2707 	if (!is_usb4_dpin(port))
2708 		return -EOPNOTSUPP;
2709 
2710 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2711 			   port->cap_adap + ADP_DP_CS_2, 1);
2712 	if (ret)
2713 		return ret;
2714 
2715 	tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
2716 	switch (tmp) {
2717 	case DP_COMMON_CAP_RATE_RBR:
2718 		*rate = 1620;
2719 		break;
2720 	case DP_COMMON_CAP_RATE_HBR:
2721 		*rate = 2700;
2722 		break;
2723 	case DP_COMMON_CAP_RATE_HBR2:
2724 		*rate = 5400;
2725 		break;
2726 	case DP_COMMON_CAP_RATE_HBR3:
2727 		*rate = 8100;
2728 		break;
2729 	}
2730 
2731 	tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
2732 	switch (tmp) {
2733 	case DP_COMMON_CAP_1_LANE:
2734 		*lanes = 1;
2735 		break;
2736 	case DP_COMMON_CAP_2_LANES:
2737 		*lanes = 2;
2738 		break;
2739 	case DP_COMMON_CAP_4_LANES:
2740 		*lanes = 4;
2741 		break;
2742 	}
2743 
2744 	return 0;
2745 }
2746 
2747 /**
2748  * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
2749  * @port: DP IN adapter
2750  * @rate: Non-reduced rate in Mb/s
2751  * @lanes: Non-reduced lanes
2752  *
2753  * Before the capabilities reduction, this function can be used to set
2754  * the non-reduced values for the DP IN adapter.
2755  *
2756  * Return:
2757  * * %0 - On success.
2758  * * %-EOPNOTSUPP - If the adapter does not support this.
2759  * * Negative errno - Another error occurred.
2760  */
2761 int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
2762 {
2763 	u32 val;
2764 	int ret;
2765 
2766 	if (!is_usb4_dpin(port))
2767 		return -EOPNOTSUPP;
2768 
2769 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2770 			   port->cap_adap + ADP_DP_CS_2, 1);
2771 	if (ret)
2772 		return ret;
2773 
2774 	val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
2775 
2776 	switch (rate) {
2777 	case 1620:
2778 		break;
2779 	case 2700:
2780 		val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
2781 			& ADP_DP_CS_2_NRD_MLR_MASK;
2782 		break;
2783 	case 5400:
2784 		val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2785 			& ADP_DP_CS_2_NRD_MLR_MASK;
2786 		break;
2787 	case 8100:
2788 		val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2789 			& ADP_DP_CS_2_NRD_MLR_MASK;
2790 		break;
2791 	default:
2792 		return -EINVAL;
2793 	}
2794 
2795 	val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
2796 
2797 	switch (lanes) {
2798 	case 1:
2799 		break;
2800 	case 2:
2801 		val |= DP_COMMON_CAP_2_LANES;
2802 		break;
2803 	case 4:
2804 		val |= DP_COMMON_CAP_4_LANES;
2805 		break;
2806 	default:
2807 		return -EINVAL;
2808 	}
2809 
2810 	return tb_port_write(port, &val, TB_CFG_PORT,
2811 			     port->cap_adap + ADP_DP_CS_2, 1);
2812 }
2813 
2814 /**
2815  * usb4_dp_port_granularity() - Return granularity for the bandwidth values
2816  * @port: DP IN adapter
2817  *
2818  * Reads the programmed granularity from @port.
2819  *
2820  * Return:
2821  * * Granularity value of a @port.
2822  * * %-EOPNOTSUPP - If the DP IN adapter does not support bandwidth
2823  *   allocation mode.
2824  * * Negative errno - Another error occurred.
2825  */
2826 int usb4_dp_port_granularity(struct tb_port *port)
2827 {
2828 	u32 val;
2829 	int ret;
2830 
2831 	if (!is_usb4_dpin(port))
2832 		return -EOPNOTSUPP;
2833 
2834 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2835 			   port->cap_adap + ADP_DP_CS_2, 1);
2836 	if (ret)
2837 		return ret;
2838 
2839 	val &= ADP_DP_CS_2_GR_MASK;
2840 	val >>= ADP_DP_CS_2_GR_SHIFT;
2841 
2842 	switch (val) {
2843 	case ADP_DP_CS_2_GR_0_25G:
2844 		return 250;
2845 	case ADP_DP_CS_2_GR_0_5G:
2846 		return 500;
2847 	case ADP_DP_CS_2_GR_1G:
2848 		return 1000;
2849 	}
2850 
2851 	return -EINVAL;
2852 }
2853 
2854 /**
2855  * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
2856  * @port: DP IN adapter
2857  * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
2858  *
2859  * Sets the granularity used with the estimated, allocated and requested
2860  * bandwidth.
2861  *
2862  * Return:
2863  * * %0 - On success.
2864  * * %-EOPNOTSUPP - If the adapter does not support this.
2865  * * Negative errno - Another error occurred.
2866  */
2867 int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
2868 {
2869 	u32 val;
2870 	int ret;
2871 
2872 	if (!is_usb4_dpin(port))
2873 		return -EOPNOTSUPP;
2874 
2875 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2876 			   port->cap_adap + ADP_DP_CS_2, 1);
2877 	if (ret)
2878 		return ret;
2879 
2880 	val &= ~ADP_DP_CS_2_GR_MASK;
2881 
2882 	switch (granularity) {
2883 	case 250:
2884 		val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
2885 		break;
2886 	case 500:
2887 		val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
2888 		break;
2889 	case 1000:
2890 		val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
2891 		break;
2892 	default:
2893 		return -EINVAL;
2894 	}
2895 
2896 	return tb_port_write(port, &val, TB_CFG_PORT,
2897 			     port->cap_adap + ADP_DP_CS_2, 1);
2898 }
2899 
2900 /**
2901  * usb4_dp_port_set_estimated_bandwidth() - Set estimated bandwidth
2902  * @port: DP IN adapter
2903  * @bw: Estimated bandwidth in Mb/s.
2904  *
2905  * Sets the estimated bandwidth to @bw. Set the granularity by calling
2906  * usb4_dp_port_set_granularity() before calling this. The @bw is rounded
2907  * down to the closest granularity multiplier.
2908  *
2909  * Return:
2910  * * %0 - On success.
2911  * * %-EOPNOTSUPP - If the adapter does not support this.
2912  * * Negative errno - Another error occurred.
2913  */
2914 int usb4_dp_port_set_estimated_bandwidth(struct tb_port *port, int bw)
2915 {
2916 	u32 val, granularity;
2917 	int ret;
2918 
2919 	if (!is_usb4_dpin(port))
2920 		return -EOPNOTSUPP;
2921 
2922 	ret = usb4_dp_port_granularity(port);
2923 	if (ret < 0)
2924 		return ret;
2925 	granularity = ret;
2926 
2927 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2928 			   port->cap_adap + ADP_DP_CS_2, 1);
2929 	if (ret)
2930 		return ret;
2931 
2932 	val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
2933 	val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
2934 
2935 	return tb_port_write(port, &val, TB_CFG_PORT,
2936 			     port->cap_adap + ADP_DP_CS_2, 1);
2937 }
2938 
2939 /**
2940  * usb4_dp_port_allocated_bandwidth() - Return allocated bandwidth
2941  * @port: DP IN adapter
2942  *
2943  * Reads the allocated bandwidth for @port in Mb/s (taking into account
2944  * the programmed granularity).
2945  *
2946  * Return: Allocated bandwidth in Mb/s or negative errno in case of an error.
2947  */
2948 int usb4_dp_port_allocated_bandwidth(struct tb_port *port)
2949 {
2950 	u32 val, granularity;
2951 	int ret;
2952 
2953 	if (!is_usb4_dpin(port))
2954 		return -EOPNOTSUPP;
2955 
2956 	ret = usb4_dp_port_granularity(port);
2957 	if (ret < 0)
2958 		return ret;
2959 	granularity = ret;
2960 
2961 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2962 			   port->cap_adap + DP_STATUS, 1);
2963 	if (ret)
2964 		return ret;
2965 
2966 	val &= DP_STATUS_ALLOCATED_BW_MASK;
2967 	val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
2968 
2969 	return val * granularity;
2970 }
2971 
2972 static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
2973 {
2974 	u32 val;
2975 	int ret;
2976 
2977 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2978 			   port->cap_adap + ADP_DP_CS_2, 1);
2979 	if (ret)
2980 		return ret;
2981 
2982 	if (ack)
2983 		val |= ADP_DP_CS_2_CA;
2984 	else
2985 		val &= ~ADP_DP_CS_2_CA;
2986 
2987 	return tb_port_write(port, &val, TB_CFG_PORT,
2988 			     port->cap_adap + ADP_DP_CS_2, 1);
2989 }
2990 
2991 static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
2992 {
2993 	return __usb4_dp_port_set_cm_ack(port, true);
2994 }
2995 
2996 static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
2997 					      int timeout_msec)
2998 {
2999 	ktime_t end;
3000 	u32 val;
3001 	int ret;
3002 
3003 	ret = __usb4_dp_port_set_cm_ack(port, false);
3004 	if (ret)
3005 		return ret;
3006 
3007 	end = ktime_add_ms(ktime_get(), timeout_msec);
3008 	do {
3009 		ret = tb_port_read(port, &val, TB_CFG_PORT,
3010 				   port->cap_adap + ADP_DP_CS_8, 1);
3011 		if (ret)
3012 			return ret;
3013 
3014 		if (!(val & ADP_DP_CS_8_DR))
3015 			break;
3016 
3017 		usleep_range(50, 100);
3018 	} while (ktime_before(ktime_get(), end));
3019 
3020 	if (val & ADP_DP_CS_8_DR) {
3021 		tb_port_warn(port, "timeout waiting for DPTX request to clear\n");
3022 		return -ETIMEDOUT;
3023 	}
3024 
3025 	ret = tb_port_read(port, &val, TB_CFG_PORT,
3026 			   port->cap_adap + ADP_DP_CS_2, 1);
3027 	if (ret)
3028 		return ret;
3029 
3030 	val &= ~ADP_DP_CS_2_CA;
3031 	return tb_port_write(port, &val, TB_CFG_PORT,
3032 			     port->cap_adap + ADP_DP_CS_2, 1);
3033 }
3034 
3035 /**
3036  * usb4_dp_port_allocate_bandwidth() - Set allocated bandwidth
3037  * @port: DP IN adapter
3038  * @bw: New allocated bandwidth in Mb/s
3039  *
3040  * Communicates the new allocated bandwidth with the DPCD (graphics
3041  * driver). Takes into account the programmed granularity.
3042  *
3043  * Return: %0 on success, negative errno otherwise.
3044  */
3045 int usb4_dp_port_allocate_bandwidth(struct tb_port *port, int bw)
3046 {
3047 	u32 val, granularity;
3048 	int ret;
3049 
3050 	if (!is_usb4_dpin(port))
3051 		return -EOPNOTSUPP;
3052 
3053 	ret = usb4_dp_port_granularity(port);
3054 	if (ret < 0)
3055 		return ret;
3056 	granularity = ret;
3057 
3058 	ret = tb_port_read(port, &val, TB_CFG_PORT,
3059 			   port->cap_adap + DP_STATUS, 1);
3060 	if (ret)
3061 		return ret;
3062 
3063 	val &= ~DP_STATUS_ALLOCATED_BW_MASK;
3064 	val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
3065 
3066 	ret = tb_port_write(port, &val, TB_CFG_PORT,
3067 			    port->cap_adap + DP_STATUS, 1);
3068 	if (ret)
3069 		return ret;
3070 
3071 	ret = usb4_dp_port_set_cm_ack(port);
3072 	if (ret)
3073 		return ret;
3074 
3075 	return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
3076 }
3077 
3078 /**
3079  * usb4_dp_port_requested_bandwidth() - Read requested bandwidth
3080  * @port: DP IN adapter
3081  *
3082  * Reads the DPCD (graphics driver) requested bandwidth and returns it
3083  * in Mb/s. Takes the programmed granularity into account.
3084  *
3085  * Return:
3086  * * Requested bandwidth in Mb/s - On success.
3087  * * %-EOPNOTSUPP - If the adapter does not support bandwidth allocation
3088  *   mode.
3089  * * %ENODATA - If there is no active bandwidth request from the graphics
3090  *   driver.
3091  * * Negative errno - On failure.
3092  */
3093 int usb4_dp_port_requested_bandwidth(struct tb_port *port)
3094 {
3095 	u32 val, granularity;
3096 	int ret;
3097 
3098 	if (!is_usb4_dpin(port))
3099 		return -EOPNOTSUPP;
3100 
3101 	ret = usb4_dp_port_granularity(port);
3102 	if (ret < 0)
3103 		return ret;
3104 	granularity = ret;
3105 
3106 	ret = tb_port_read(port, &val, TB_CFG_PORT,
3107 			   port->cap_adap + ADP_DP_CS_8, 1);
3108 	if (ret)
3109 		return ret;
3110 
3111 	if (!(val & ADP_DP_CS_8_DR))
3112 		return -ENODATA;
3113 
3114 	return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
3115 }
3116 
3117 /**
3118  * usb4_pci_port_set_ext_encapsulation() - Enable/disable extended encapsulation
3119  * @port: PCIe adapter
3120  * @enable: Enable/disable extended encapsulation
3121  *
3122  * Enables or disables extended encapsulation used in PCIe tunneling. Caller
3123  * needs to make sure both adapters support this before enabling.
3124  *
3125  * Return: %0 on success, negative errno otherwise.
3126  */
3127 int usb4_pci_port_set_ext_encapsulation(struct tb_port *port, bool enable)
3128 {
3129 	u32 val;
3130 	int ret;
3131 
3132 	if (!tb_port_is_pcie_up(port) && !tb_port_is_pcie_down(port))
3133 		return -EINVAL;
3134 
3135 	ret = tb_port_read(port, &val, TB_CFG_PORT,
3136 			   port->cap_adap + ADP_PCIE_CS_1, 1);
3137 	if (ret)
3138 		return ret;
3139 
3140 	if (enable)
3141 		val |= ADP_PCIE_CS_1_EE;
3142 	else
3143 		val &= ~ADP_PCIE_CS_1_EE;
3144 
3145 	return tb_port_write(port, &val, TB_CFG_PORT,
3146 			     port->cap_adap + ADP_PCIE_CS_1, 1);
3147 }
3148