xref: /linux/drivers/thunderbolt/usb4.c (revision 6e7fd890f1d6ac83805409e9c346240de2705584)
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/units.h>
13 
14 #include "sb_regs.h"
15 #include "tb.h"
16 
17 #define USB4_DATA_RETRIES		3
18 #define USB4_DATA_DWORDS		16
19 
20 #define USB4_NVM_READ_OFFSET_MASK	GENMASK(23, 2)
21 #define USB4_NVM_READ_OFFSET_SHIFT	2
22 #define USB4_NVM_READ_LENGTH_MASK	GENMASK(27, 24)
23 #define USB4_NVM_READ_LENGTH_SHIFT	24
24 
25 #define USB4_NVM_SET_OFFSET_MASK	USB4_NVM_READ_OFFSET_MASK
26 #define USB4_NVM_SET_OFFSET_SHIFT	USB4_NVM_READ_OFFSET_SHIFT
27 
28 #define USB4_DROM_ADDRESS_MASK		GENMASK(14, 2)
29 #define USB4_DROM_ADDRESS_SHIFT		2
30 #define USB4_DROM_SIZE_MASK		GENMASK(19, 15)
31 #define USB4_DROM_SIZE_SHIFT		15
32 
33 #define USB4_NVM_SECTOR_SIZE_MASK	GENMASK(23, 0)
34 
35 #define USB4_BA_LENGTH_MASK		GENMASK(7, 0)
36 #define USB4_BA_INDEX_MASK		GENMASK(15, 0)
37 
38 enum usb4_ba_index {
39 	USB4_BA_MAX_USB3 = 0x1,
40 	USB4_BA_MIN_DP_AUX = 0x2,
41 	USB4_BA_MIN_DP_MAIN = 0x3,
42 	USB4_BA_MAX_PCIE = 0x4,
43 	USB4_BA_MAX_HI = 0x5,
44 };
45 
46 #define USB4_BA_VALUE_MASK		GENMASK(31, 16)
47 #define USB4_BA_VALUE_SHIFT		16
48 
49 /* Delays in us used with usb4_port_wait_for_bit() */
50 #define USB4_PORT_DELAY			50
51 #define USB4_PORT_SB_DELAY		5000
52 
53 static int usb4_native_switch_op(struct tb_switch *sw, u16 opcode,
54 				 u32 *metadata, u8 *status,
55 				 const void *tx_data, size_t tx_dwords,
56 				 void *rx_data, size_t rx_dwords)
57 {
58 	u32 val;
59 	int ret;
60 
61 	if (metadata) {
62 		ret = tb_sw_write(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
63 		if (ret)
64 			return ret;
65 	}
66 	if (tx_dwords) {
67 		ret = tb_sw_write(sw, tx_data, TB_CFG_SWITCH, ROUTER_CS_9,
68 				  tx_dwords);
69 		if (ret)
70 			return ret;
71 	}
72 
73 	val = opcode | ROUTER_CS_26_OV;
74 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
75 	if (ret)
76 		return ret;
77 
78 	ret = tb_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
79 	if (ret)
80 		return ret;
81 
82 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
83 	if (ret)
84 		return ret;
85 
86 	if (val & ROUTER_CS_26_ONS)
87 		return -EOPNOTSUPP;
88 
89 	if (status)
90 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
91 			ROUTER_CS_26_STATUS_SHIFT;
92 
93 	if (metadata) {
94 		ret = tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
95 		if (ret)
96 			return ret;
97 	}
98 	if (rx_dwords) {
99 		ret = tb_sw_read(sw, rx_data, TB_CFG_SWITCH, ROUTER_CS_9,
100 				 rx_dwords);
101 		if (ret)
102 			return ret;
103 	}
104 
105 	return 0;
106 }
107 
108 static int __usb4_switch_op(struct tb_switch *sw, u16 opcode, u32 *metadata,
109 			    u8 *status, const void *tx_data, size_t tx_dwords,
110 			    void *rx_data, size_t rx_dwords)
111 {
112 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
113 
114 	if (tx_dwords > USB4_DATA_DWORDS || rx_dwords > USB4_DATA_DWORDS)
115 		return -EINVAL;
116 
117 	/*
118 	 * If the connection manager implementation provides USB4 router
119 	 * operation proxy callback, call it here instead of running the
120 	 * operation natively.
121 	 */
122 	if (cm_ops->usb4_switch_op) {
123 		int ret;
124 
125 		ret = cm_ops->usb4_switch_op(sw, opcode, metadata, status,
126 					     tx_data, tx_dwords, rx_data,
127 					     rx_dwords);
128 		if (ret != -EOPNOTSUPP)
129 			return ret;
130 
131 		/*
132 		 * If the proxy was not supported then run the native
133 		 * router operation instead.
134 		 */
135 	}
136 
137 	return usb4_native_switch_op(sw, opcode, metadata, status, tx_data,
138 				     tx_dwords, rx_data, rx_dwords);
139 }
140 
141 static inline int usb4_switch_op(struct tb_switch *sw, u16 opcode,
142 				 u32 *metadata, u8 *status)
143 {
144 	return __usb4_switch_op(sw, opcode, metadata, status, NULL, 0, NULL, 0);
145 }
146 
147 static inline int usb4_switch_op_data(struct tb_switch *sw, u16 opcode,
148 				      u32 *metadata, u8 *status,
149 				      const void *tx_data, size_t tx_dwords,
150 				      void *rx_data, size_t rx_dwords)
151 {
152 	return __usb4_switch_op(sw, opcode, metadata, status, tx_data,
153 				tx_dwords, rx_data, rx_dwords);
154 }
155 
156 /**
157  * usb4_switch_check_wakes() - Check for wakes and notify PM core about them
158  * @sw: Router whose wakes to check
159  *
160  * Checks wakes occurred during suspend and notify the PM core about them.
161  */
162 void usb4_switch_check_wakes(struct tb_switch *sw)
163 {
164 	bool wakeup_usb4 = false;
165 	struct usb4_port *usb4;
166 	struct tb_port *port;
167 	bool wakeup = false;
168 	u32 val;
169 
170 	if (tb_route(sw)) {
171 		if (tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1))
172 			return;
173 
174 		tb_sw_dbg(sw, "PCIe wake: %s, USB3 wake: %s\n",
175 			  (val & ROUTER_CS_6_WOPS) ? "yes" : "no",
176 			  (val & ROUTER_CS_6_WOUS) ? "yes" : "no");
177 
178 		wakeup = val & (ROUTER_CS_6_WOPS | ROUTER_CS_6_WOUS);
179 	}
180 
181 	/*
182 	 * Check for any downstream ports for USB4 wake,
183 	 * connection wake and disconnection wake.
184 	 */
185 	tb_switch_for_each_port(sw, port) {
186 		if (!port->cap_usb4)
187 			continue;
188 
189 		if (tb_port_read(port, &val, TB_CFG_PORT,
190 				 port->cap_usb4 + PORT_CS_18, 1))
191 			break;
192 
193 		tb_port_dbg(port, "USB4 wake: %s, connection wake: %s, disconnection wake: %s\n",
194 			    (val & PORT_CS_18_WOU4S) ? "yes" : "no",
195 			    (val & PORT_CS_18_WOCS) ? "yes" : "no",
196 			    (val & PORT_CS_18_WODS) ? "yes" : "no");
197 
198 		wakeup_usb4 = val & (PORT_CS_18_WOU4S | PORT_CS_18_WOCS |
199 				     PORT_CS_18_WODS);
200 
201 		usb4 = port->usb4;
202 		if (device_may_wakeup(&usb4->dev) && wakeup_usb4)
203 			pm_wakeup_event(&usb4->dev, 0);
204 
205 		wakeup |= wakeup_usb4;
206 	}
207 
208 	if (wakeup)
209 		pm_wakeup_event(&sw->dev, 0);
210 }
211 
212 static bool link_is_usb4(struct tb_port *port)
213 {
214 	u32 val;
215 
216 	if (!port->cap_usb4)
217 		return false;
218 
219 	if (tb_port_read(port, &val, TB_CFG_PORT,
220 			 port->cap_usb4 + PORT_CS_18, 1))
221 		return false;
222 
223 	return !(val & PORT_CS_18_TCM);
224 }
225 
226 /**
227  * usb4_switch_setup() - Additional setup for USB4 device
228  * @sw: USB4 router to setup
229  *
230  * USB4 routers need additional settings in order to enable all the
231  * tunneling. This function enables USB and PCIe tunneling if it can be
232  * enabled (e.g the parent switch also supports them). If USB tunneling
233  * is not available for some reason (like that there is Thunderbolt 3
234  * switch upstream) then the internal xHCI controller is enabled
235  * instead.
236  *
237  * This does not set the configuration valid bit of the router. To do
238  * that call usb4_switch_configuration_valid().
239  */
240 int usb4_switch_setup(struct tb_switch *sw)
241 {
242 	struct tb_switch *parent = tb_switch_parent(sw);
243 	struct tb_port *down;
244 	bool tbt3, xhci;
245 	u32 val = 0;
246 	int ret;
247 
248 	if (!tb_route(sw))
249 		return 0;
250 
251 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
252 	if (ret)
253 		return ret;
254 
255 	down = tb_switch_downstream_port(sw);
256 	sw->link_usb4 = link_is_usb4(down);
257 	tb_sw_dbg(sw, "link: %s\n", sw->link_usb4 ? "USB4" : "TBT");
258 
259 	xhci = val & ROUTER_CS_6_HCI;
260 	tbt3 = !(val & ROUTER_CS_6_TNS);
261 
262 	tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
263 		  tbt3 ? "yes" : "no", xhci ? "yes" : "no");
264 
265 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
266 	if (ret)
267 		return ret;
268 
269 	if (tb_acpi_may_tunnel_usb3() && sw->link_usb4 &&
270 	    tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
271 		val |= ROUTER_CS_5_UTO;
272 		xhci = false;
273 	}
274 
275 	/*
276 	 * Only enable PCIe tunneling if the parent router supports it
277 	 * and it is not disabled.
278 	 */
279 	if (tb_acpi_may_tunnel_pcie() &&
280 	    tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
281 		val |= ROUTER_CS_5_PTO;
282 		/*
283 		 * xHCI can be enabled if PCIe tunneling is supported
284 		 * and the parent does not have any USB3 dowstream
285 		 * adapters (so we cannot do USB 3.x tunneling).
286 		 */
287 		if (xhci)
288 			val |= ROUTER_CS_5_HCO;
289 	}
290 
291 	/* TBT3 supported by the CM */
292 	val &= ~ROUTER_CS_5_CNS;
293 
294 	return tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
295 }
296 
297 /**
298  * usb4_switch_configuration_valid() - Set tunneling configuration to be valid
299  * @sw: USB4 router
300  *
301  * Sets configuration valid bit for the router. Must be called before
302  * any tunnels can be set through the router and after
303  * usb4_switch_setup() has been called. Can be called to host and device
304  * routers (does nothing for the latter).
305  *
306  * Returns %0 in success and negative errno otherwise.
307  */
308 int usb4_switch_configuration_valid(struct tb_switch *sw)
309 {
310 	u32 val;
311 	int ret;
312 
313 	if (!tb_route(sw))
314 		return 0;
315 
316 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
317 	if (ret)
318 		return ret;
319 
320 	val |= ROUTER_CS_5_CV;
321 
322 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
323 	if (ret)
324 		return ret;
325 
326 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
327 				      ROUTER_CS_6_CR, 50);
328 }
329 
330 /**
331  * usb4_switch_read_uid() - Read UID from USB4 router
332  * @sw: USB4 router
333  * @uid: UID is stored here
334  *
335  * Reads 64-bit UID from USB4 router config space.
336  */
337 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
338 {
339 	return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
340 }
341 
342 static int usb4_switch_drom_read_block(void *data,
343 				       unsigned int dwaddress, void *buf,
344 				       size_t dwords)
345 {
346 	struct tb_switch *sw = data;
347 	u8 status = 0;
348 	u32 metadata;
349 	int ret;
350 
351 	metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
352 	metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
353 		USB4_DROM_ADDRESS_MASK;
354 
355 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_DROM_READ, &metadata,
356 				  &status, NULL, 0, buf, dwords);
357 	if (ret)
358 		return ret;
359 
360 	return status ? -EIO : 0;
361 }
362 
363 /**
364  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
365  * @sw: USB4 router
366  * @address: Byte address inside DROM to start reading
367  * @buf: Buffer where the DROM content is stored
368  * @size: Number of bytes to read from DROM
369  *
370  * Uses USB4 router operations to read router DROM. For devices this
371  * should always work but for hosts it may return %-EOPNOTSUPP in which
372  * case the host router does not have DROM.
373  */
374 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
375 			  size_t size)
376 {
377 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
378 				usb4_switch_drom_read_block, sw);
379 }
380 
381 /**
382  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
383  * @sw: USB4 router
384  *
385  * Checks whether conditions are met so that lane bonding can be
386  * established with the upstream router. Call only for device routers.
387  */
388 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
389 {
390 	struct tb_port *up;
391 	int ret;
392 	u32 val;
393 
394 	up = tb_upstream_port(sw);
395 	ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
396 	if (ret)
397 		return false;
398 
399 	return !!(val & PORT_CS_18_BE);
400 }
401 
402 /**
403  * usb4_switch_set_wake() - Enabled/disable wake
404  * @sw: USB4 router
405  * @flags: Wakeup flags (%0 to disable)
406  *
407  * Enables/disables router to wake up from sleep.
408  */
409 int usb4_switch_set_wake(struct tb_switch *sw, unsigned int flags)
410 {
411 	struct usb4_port *usb4;
412 	struct tb_port *port;
413 	u64 route = tb_route(sw);
414 	u32 val;
415 	int ret;
416 
417 	/*
418 	 * Enable wakes coming from all USB4 downstream ports (from
419 	 * child routers). For device routers do this also for the
420 	 * upstream USB4 port.
421 	 */
422 	tb_switch_for_each_port(sw, port) {
423 		if (!tb_port_is_null(port))
424 			continue;
425 		if (!route && tb_is_upstream_port(port))
426 			continue;
427 		if (!port->cap_usb4)
428 			continue;
429 
430 		ret = tb_port_read(port, &val, TB_CFG_PORT,
431 				   port->cap_usb4 + PORT_CS_19, 1);
432 		if (ret)
433 			return ret;
434 
435 		val &= ~(PORT_CS_19_WOC | PORT_CS_19_WOD | PORT_CS_19_WOU4);
436 
437 		if (tb_is_upstream_port(port)) {
438 			val |= PORT_CS_19_WOU4;
439 		} else {
440 			bool configured = val & PORT_CS_19_PC;
441 			usb4 = port->usb4;
442 
443 			if (((flags & TB_WAKE_ON_CONNECT) |
444 			      device_may_wakeup(&usb4->dev)) && !configured)
445 				val |= PORT_CS_19_WOC;
446 			if (((flags & TB_WAKE_ON_DISCONNECT) |
447 			      device_may_wakeup(&usb4->dev)) && configured)
448 				val |= PORT_CS_19_WOD;
449 			if ((flags & TB_WAKE_ON_USB4) && configured)
450 				val |= PORT_CS_19_WOU4;
451 		}
452 
453 		ret = tb_port_write(port, &val, TB_CFG_PORT,
454 				    port->cap_usb4 + PORT_CS_19, 1);
455 		if (ret)
456 			return ret;
457 	}
458 
459 	/*
460 	 * Enable wakes from PCIe, USB 3.x and DP on this router. Only
461 	 * needed for device routers.
462 	 */
463 	if (route) {
464 		ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
465 		if (ret)
466 			return ret;
467 
468 		val &= ~(ROUTER_CS_5_WOP | ROUTER_CS_5_WOU | ROUTER_CS_5_WOD);
469 		if (flags & TB_WAKE_ON_USB3)
470 			val |= ROUTER_CS_5_WOU;
471 		if (flags & TB_WAKE_ON_PCIE)
472 			val |= ROUTER_CS_5_WOP;
473 		if (flags & TB_WAKE_ON_DP)
474 			val |= ROUTER_CS_5_WOD;
475 
476 		ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
477 		if (ret)
478 			return ret;
479 	}
480 
481 	return 0;
482 }
483 
484 /**
485  * usb4_switch_set_sleep() - Prepare the router to enter sleep
486  * @sw: USB4 router
487  *
488  * Sets sleep bit for the router. Returns when the router sleep ready
489  * bit has been asserted.
490  */
491 int usb4_switch_set_sleep(struct tb_switch *sw)
492 {
493 	int ret;
494 	u32 val;
495 
496 	/* Set sleep bit and wait for sleep ready to be asserted */
497 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
498 	if (ret)
499 		return ret;
500 
501 	val |= ROUTER_CS_5_SLP;
502 
503 	ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
504 	if (ret)
505 		return ret;
506 
507 	return tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
508 				      ROUTER_CS_6_SLPR, 500);
509 }
510 
511 /**
512  * usb4_switch_nvm_sector_size() - Return router NVM sector size
513  * @sw: USB4 router
514  *
515  * If the router supports NVM operations this function returns the NVM
516  * sector size in bytes. If NVM operations are not supported returns
517  * %-EOPNOTSUPP.
518  */
519 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
520 {
521 	u32 metadata;
522 	u8 status;
523 	int ret;
524 
525 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &metadata,
526 			     &status);
527 	if (ret)
528 		return ret;
529 
530 	if (status)
531 		return status == 0x2 ? -EOPNOTSUPP : -EIO;
532 
533 	return metadata & USB4_NVM_SECTOR_SIZE_MASK;
534 }
535 
536 static int usb4_switch_nvm_read_block(void *data,
537 	unsigned int dwaddress, void *buf, size_t dwords)
538 {
539 	struct tb_switch *sw = data;
540 	u8 status = 0;
541 	u32 metadata;
542 	int ret;
543 
544 	metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
545 		   USB4_NVM_READ_LENGTH_MASK;
546 	metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
547 		   USB4_NVM_READ_OFFSET_MASK;
548 
549 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_READ, &metadata,
550 				  &status, NULL, 0, buf, dwords);
551 	if (ret)
552 		return ret;
553 
554 	return status ? -EIO : 0;
555 }
556 
557 /**
558  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
559  * @sw: USB4 router
560  * @address: Starting address in bytes
561  * @buf: Read data is placed here
562  * @size: How many bytes to read
563  *
564  * Reads NVM contents of the router. If NVM is not supported returns
565  * %-EOPNOTSUPP.
566  */
567 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
568 			 size_t size)
569 {
570 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
571 				usb4_switch_nvm_read_block, sw);
572 }
573 
574 /**
575  * usb4_switch_nvm_set_offset() - Set NVM write offset
576  * @sw: USB4 router
577  * @address: Start offset
578  *
579  * Explicitly sets NVM write offset. Normally when writing to NVM this
580  * is done automatically by usb4_switch_nvm_write().
581  *
582  * Returns %0 in success and negative errno if there was a failure.
583  */
584 int usb4_switch_nvm_set_offset(struct tb_switch *sw, unsigned int address)
585 {
586 	u32 metadata, dwaddress;
587 	u8 status = 0;
588 	int ret;
589 
590 	dwaddress = address / 4;
591 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
592 		   USB4_NVM_SET_OFFSET_MASK;
593 
594 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &metadata,
595 			     &status);
596 	if (ret)
597 		return ret;
598 
599 	return status ? -EIO : 0;
600 }
601 
602 static int usb4_switch_nvm_write_next_block(void *data, unsigned int dwaddress,
603 					    const void *buf, size_t dwords)
604 {
605 	struct tb_switch *sw = data;
606 	u8 status;
607 	int ret;
608 
609 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_NVM_WRITE, NULL, &status,
610 				  buf, dwords, NULL, 0);
611 	if (ret)
612 		return ret;
613 
614 	return status ? -EIO : 0;
615 }
616 
617 /**
618  * usb4_switch_nvm_write() - Write to the router NVM
619  * @sw: USB4 router
620  * @address: Start address where to write in bytes
621  * @buf: Pointer to the data to write
622  * @size: Size of @buf in bytes
623  *
624  * Writes @buf to the router NVM using USB4 router operations. If NVM
625  * write is not supported returns %-EOPNOTSUPP.
626  */
627 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
628 			  const void *buf, size_t size)
629 {
630 	int ret;
631 
632 	ret = usb4_switch_nvm_set_offset(sw, address);
633 	if (ret)
634 		return ret;
635 
636 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
637 				 usb4_switch_nvm_write_next_block, sw);
638 }
639 
640 /**
641  * usb4_switch_nvm_authenticate() - Authenticate new NVM
642  * @sw: USB4 router
643  *
644  * After the new NVM has been written via usb4_switch_nvm_write(), this
645  * function triggers NVM authentication process. The router gets power
646  * cycled and if the authentication is successful the new NVM starts
647  * running. In case of failure returns negative errno.
648  *
649  * The caller should call usb4_switch_nvm_authenticate_status() to read
650  * the status of the authentication after power cycle. It should be the
651  * first router operation to avoid the status being lost.
652  */
653 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
654 {
655 	int ret;
656 
657 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, NULL, NULL);
658 	switch (ret) {
659 	/*
660 	 * The router is power cycled once NVM_AUTH is started so it is
661 	 * expected to get any of the following errors back.
662 	 */
663 	case -EACCES:
664 	case -ENOTCONN:
665 	case -ETIMEDOUT:
666 		return 0;
667 
668 	default:
669 		return ret;
670 	}
671 }
672 
673 /**
674  * usb4_switch_nvm_authenticate_status() - Read status of last NVM authenticate
675  * @sw: USB4 router
676  * @status: Status code of the operation
677  *
678  * The function checks if there is status available from the last NVM
679  * authenticate router operation. If there is status then %0 is returned
680  * and the status code is placed in @status. Returns negative errno in case
681  * of failure.
682  *
683  * Must be called before any other router operation.
684  */
685 int usb4_switch_nvm_authenticate_status(struct tb_switch *sw, u32 *status)
686 {
687 	const struct tb_cm_ops *cm_ops = sw->tb->cm_ops;
688 	u16 opcode;
689 	u32 val;
690 	int ret;
691 
692 	if (cm_ops->usb4_switch_nvm_authenticate_status) {
693 		ret = cm_ops->usb4_switch_nvm_authenticate_status(sw, status);
694 		if (ret != -EOPNOTSUPP)
695 			return ret;
696 	}
697 
698 	ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
699 	if (ret)
700 		return ret;
701 
702 	/* Check that the opcode is correct */
703 	opcode = val & ROUTER_CS_26_OPCODE_MASK;
704 	if (opcode == USB4_SWITCH_OP_NVM_AUTH) {
705 		if (val & ROUTER_CS_26_OV)
706 			return -EBUSY;
707 		if (val & ROUTER_CS_26_ONS)
708 			return -EOPNOTSUPP;
709 
710 		*status = (val & ROUTER_CS_26_STATUS_MASK) >>
711 			ROUTER_CS_26_STATUS_SHIFT;
712 	} else {
713 		*status = 0;
714 	}
715 
716 	return 0;
717 }
718 
719 /**
720  * usb4_switch_credits_init() - Read buffer allocation parameters
721  * @sw: USB4 router
722  *
723  * Reads @sw buffer allocation parameters and initializes @sw buffer
724  * allocation fields accordingly. Specifically @sw->credits_allocation
725  * is set to %true if these parameters can be used in tunneling.
726  *
727  * Returns %0 on success and negative errno otherwise.
728  */
729 int usb4_switch_credits_init(struct tb_switch *sw)
730 {
731 	int max_usb3, min_dp_aux, min_dp_main, max_pcie, max_dma;
732 	int ret, length, i, nports;
733 	const struct tb_port *port;
734 	u32 data[USB4_DATA_DWORDS];
735 	u32 metadata = 0;
736 	u8 status = 0;
737 
738 	memset(data, 0, sizeof(data));
739 	ret = usb4_switch_op_data(sw, USB4_SWITCH_OP_BUFFER_ALLOC, &metadata,
740 				  &status, NULL, 0, data, ARRAY_SIZE(data));
741 	if (ret)
742 		return ret;
743 	if (status)
744 		return -EIO;
745 
746 	length = metadata & USB4_BA_LENGTH_MASK;
747 	if (WARN_ON(length > ARRAY_SIZE(data)))
748 		return -EMSGSIZE;
749 
750 	max_usb3 = -1;
751 	min_dp_aux = -1;
752 	min_dp_main = -1;
753 	max_pcie = -1;
754 	max_dma = -1;
755 
756 	tb_sw_dbg(sw, "credit allocation parameters:\n");
757 
758 	for (i = 0; i < length; i++) {
759 		u16 index, value;
760 
761 		index = data[i] & USB4_BA_INDEX_MASK;
762 		value = (data[i] & USB4_BA_VALUE_MASK) >> USB4_BA_VALUE_SHIFT;
763 
764 		switch (index) {
765 		case USB4_BA_MAX_USB3:
766 			tb_sw_dbg(sw, " USB3: %u\n", value);
767 			max_usb3 = value;
768 			break;
769 		case USB4_BA_MIN_DP_AUX:
770 			tb_sw_dbg(sw, " DP AUX: %u\n", value);
771 			min_dp_aux = value;
772 			break;
773 		case USB4_BA_MIN_DP_MAIN:
774 			tb_sw_dbg(sw, " DP main: %u\n", value);
775 			min_dp_main = value;
776 			break;
777 		case USB4_BA_MAX_PCIE:
778 			tb_sw_dbg(sw, " PCIe: %u\n", value);
779 			max_pcie = value;
780 			break;
781 		case USB4_BA_MAX_HI:
782 			tb_sw_dbg(sw, " DMA: %u\n", value);
783 			max_dma = value;
784 			break;
785 		default:
786 			tb_sw_dbg(sw, " unknown credit allocation index %#x, skipping\n",
787 				  index);
788 			break;
789 		}
790 	}
791 
792 	/*
793 	 * Validate the buffer allocation preferences. If we find
794 	 * issues, log a warning and fall back using the hard-coded
795 	 * values.
796 	 */
797 
798 	/* Host router must report baMaxHI */
799 	if (!tb_route(sw) && max_dma < 0) {
800 		tb_sw_warn(sw, "host router is missing baMaxHI\n");
801 		goto err_invalid;
802 	}
803 
804 	nports = 0;
805 	tb_switch_for_each_port(sw, port) {
806 		if (tb_port_is_null(port))
807 			nports++;
808 	}
809 
810 	/* Must have DP buffer allocation (multiple USB4 ports) */
811 	if (nports > 2 && (min_dp_aux < 0 || min_dp_main < 0)) {
812 		tb_sw_warn(sw, "multiple USB4 ports require baMinDPaux/baMinDPmain\n");
813 		goto err_invalid;
814 	}
815 
816 	tb_switch_for_each_port(sw, port) {
817 		if (tb_port_is_dpout(port) && min_dp_main < 0) {
818 			tb_sw_warn(sw, "missing baMinDPmain");
819 			goto err_invalid;
820 		}
821 		if ((tb_port_is_dpin(port) || tb_port_is_dpout(port)) &&
822 		    min_dp_aux < 0) {
823 			tb_sw_warn(sw, "missing baMinDPaux");
824 			goto err_invalid;
825 		}
826 		if ((tb_port_is_usb3_down(port) || tb_port_is_usb3_up(port)) &&
827 		    max_usb3 < 0) {
828 			tb_sw_warn(sw, "missing baMaxUSB3");
829 			goto err_invalid;
830 		}
831 		if ((tb_port_is_pcie_down(port) || tb_port_is_pcie_up(port)) &&
832 		    max_pcie < 0) {
833 			tb_sw_warn(sw, "missing baMaxPCIe");
834 			goto err_invalid;
835 		}
836 	}
837 
838 	/*
839 	 * Buffer allocation passed the validation so we can use it in
840 	 * path creation.
841 	 */
842 	sw->credit_allocation = true;
843 	if (max_usb3 > 0)
844 		sw->max_usb3_credits = max_usb3;
845 	if (min_dp_aux > 0)
846 		sw->min_dp_aux_credits = min_dp_aux;
847 	if (min_dp_main > 0)
848 		sw->min_dp_main_credits = min_dp_main;
849 	if (max_pcie > 0)
850 		sw->max_pcie_credits = max_pcie;
851 	if (max_dma > 0)
852 		sw->max_dma_credits = max_dma;
853 
854 	return 0;
855 
856 err_invalid:
857 	return -EINVAL;
858 }
859 
860 /**
861  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
862  * @sw: USB4 router
863  * @in: DP IN adapter
864  *
865  * For DP tunneling this function can be used to query availability of
866  * DP IN resource. Returns true if the resource is available for DP
867  * tunneling, false otherwise.
868  */
869 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
870 {
871 	u32 metadata = in->port;
872 	u8 status;
873 	int ret;
874 
875 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &metadata,
876 			     &status);
877 	/*
878 	 * If DP resource allocation is not supported assume it is
879 	 * always available.
880 	 */
881 	if (ret == -EOPNOTSUPP)
882 		return true;
883 	if (ret)
884 		return false;
885 
886 	return !status;
887 }
888 
889 /**
890  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
891  * @sw: USB4 router
892  * @in: DP IN adapter
893  *
894  * Allocates DP IN resource for DP tunneling using USB4 router
895  * operations. If the resource was allocated returns %0. Otherwise
896  * returns negative errno, in particular %-EBUSY if the resource is
897  * already allocated.
898  */
899 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
900 {
901 	u32 metadata = in->port;
902 	u8 status;
903 	int ret;
904 
905 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &metadata,
906 			     &status);
907 	if (ret == -EOPNOTSUPP)
908 		return 0;
909 	if (ret)
910 		return ret;
911 
912 	return status ? -EBUSY : 0;
913 }
914 
915 /**
916  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
917  * @sw: USB4 router
918  * @in: DP IN adapter
919  *
920  * Releases the previously allocated DP IN resource.
921  */
922 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
923 {
924 	u32 metadata = in->port;
925 	u8 status;
926 	int ret;
927 
928 	ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &metadata,
929 			     &status);
930 	if (ret == -EOPNOTSUPP)
931 		return 0;
932 	if (ret)
933 		return ret;
934 
935 	return status ? -EIO : 0;
936 }
937 
938 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
939 {
940 	struct tb_port *p;
941 	int usb4_idx = 0;
942 
943 	/* Assume port is primary */
944 	tb_switch_for_each_port(sw, p) {
945 		if (!tb_port_is_null(p))
946 			continue;
947 		if (tb_is_upstream_port(p))
948 			continue;
949 		if (!p->link_nr) {
950 			if (p == port)
951 				break;
952 			usb4_idx++;
953 		}
954 	}
955 
956 	return usb4_idx;
957 }
958 
959 /**
960  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
961  * @sw: USB4 router
962  * @port: USB4 port
963  *
964  * USB4 routers have direct mapping between USB4 ports and PCIe
965  * downstream adapters where the PCIe topology is extended. This
966  * function returns the corresponding downstream PCIe adapter or %NULL
967  * if no such mapping was possible.
968  */
969 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
970 					  const struct tb_port *port)
971 {
972 	int usb4_idx = usb4_port_idx(sw, port);
973 	struct tb_port *p;
974 	int pcie_idx = 0;
975 
976 	/* Find PCIe down port matching usb4_port */
977 	tb_switch_for_each_port(sw, p) {
978 		if (!tb_port_is_pcie_down(p))
979 			continue;
980 
981 		if (pcie_idx == usb4_idx)
982 			return p;
983 
984 		pcie_idx++;
985 	}
986 
987 	return NULL;
988 }
989 
990 /**
991  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
992  * @sw: USB4 router
993  * @port: USB4 port
994  *
995  * USB4 routers have direct mapping between USB4 ports and USB 3.x
996  * downstream adapters where the USB 3.x topology is extended. This
997  * function returns the corresponding downstream USB 3.x adapter or
998  * %NULL if no such mapping was possible.
999  */
1000 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
1001 					  const struct tb_port *port)
1002 {
1003 	int usb4_idx = usb4_port_idx(sw, port);
1004 	struct tb_port *p;
1005 	int usb_idx = 0;
1006 
1007 	/* Find USB3 down port matching usb4_port */
1008 	tb_switch_for_each_port(sw, p) {
1009 		if (!tb_port_is_usb3_down(p))
1010 			continue;
1011 
1012 		if (usb_idx == usb4_idx)
1013 			return p;
1014 
1015 		usb_idx++;
1016 	}
1017 
1018 	return NULL;
1019 }
1020 
1021 /**
1022  * usb4_switch_add_ports() - Add USB4 ports for this router
1023  * @sw: USB4 router
1024  *
1025  * For USB4 router finds all USB4 ports and registers devices for each.
1026  * Can be called to any router.
1027  *
1028  * Return %0 in case of success and negative errno in case of failure.
1029  */
1030 int usb4_switch_add_ports(struct tb_switch *sw)
1031 {
1032 	struct tb_port *port;
1033 
1034 	if (tb_switch_is_icm(sw) || !tb_switch_is_usb4(sw))
1035 		return 0;
1036 
1037 	tb_switch_for_each_port(sw, port) {
1038 		struct usb4_port *usb4;
1039 
1040 		if (!tb_port_is_null(port))
1041 			continue;
1042 		if (!port->cap_usb4)
1043 			continue;
1044 
1045 		usb4 = usb4_port_device_add(port);
1046 		if (IS_ERR(usb4)) {
1047 			usb4_switch_remove_ports(sw);
1048 			return PTR_ERR(usb4);
1049 		}
1050 
1051 		port->usb4 = usb4;
1052 	}
1053 
1054 	return 0;
1055 }
1056 
1057 /**
1058  * usb4_switch_remove_ports() - Removes USB4 ports from this router
1059  * @sw: USB4 router
1060  *
1061  * Unregisters previously registered USB4 ports.
1062  */
1063 void usb4_switch_remove_ports(struct tb_switch *sw)
1064 {
1065 	struct tb_port *port;
1066 
1067 	tb_switch_for_each_port(sw, port) {
1068 		if (port->usb4) {
1069 			usb4_port_device_remove(port->usb4);
1070 			port->usb4 = NULL;
1071 		}
1072 	}
1073 }
1074 
1075 /**
1076  * usb4_port_unlock() - Unlock USB4 downstream port
1077  * @port: USB4 port to unlock
1078  *
1079  * Unlocks USB4 downstream port so that the connection manager can
1080  * access the router below this port.
1081  */
1082 int usb4_port_unlock(struct tb_port *port)
1083 {
1084 	int ret;
1085 	u32 val;
1086 
1087 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1088 	if (ret)
1089 		return ret;
1090 
1091 	val &= ~ADP_CS_4_LCK;
1092 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
1093 }
1094 
1095 /**
1096  * usb4_port_hotplug_enable() - Enables hotplug for a port
1097  * @port: USB4 port to operate on
1098  *
1099  * Enables hot plug events on a given port. This is only intended
1100  * to be used on lane, DP-IN, and DP-OUT adapters.
1101  */
1102 int usb4_port_hotplug_enable(struct tb_port *port)
1103 {
1104 	int ret;
1105 	u32 val;
1106 
1107 	ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1108 	if (ret)
1109 		return ret;
1110 
1111 	val &= ~ADP_CS_5_DHP;
1112 	return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_5, 1);
1113 }
1114 
1115 /**
1116  * usb4_port_reset() - Issue downstream port reset
1117  * @port: USB4 port to reset
1118  *
1119  * Issues downstream port reset to @port.
1120  */
1121 int usb4_port_reset(struct tb_port *port)
1122 {
1123 	int ret;
1124 	u32 val;
1125 
1126 	if (!port->cap_usb4)
1127 		return -EINVAL;
1128 
1129 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1130 			   port->cap_usb4 + PORT_CS_19, 1);
1131 	if (ret)
1132 		return ret;
1133 
1134 	val |= PORT_CS_19_DPR;
1135 
1136 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1137 			    port->cap_usb4 + PORT_CS_19, 1);
1138 	if (ret)
1139 		return ret;
1140 
1141 	fsleep(10000);
1142 
1143 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1144 			   port->cap_usb4 + PORT_CS_19, 1);
1145 	if (ret)
1146 		return ret;
1147 
1148 	val &= ~PORT_CS_19_DPR;
1149 
1150 	return tb_port_write(port, &val, TB_CFG_PORT,
1151 			     port->cap_usb4 + PORT_CS_19, 1);
1152 }
1153 
1154 static int usb4_port_set_configured(struct tb_port *port, bool configured)
1155 {
1156 	int ret;
1157 	u32 val;
1158 
1159 	if (!port->cap_usb4)
1160 		return -EINVAL;
1161 
1162 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1163 			   port->cap_usb4 + PORT_CS_19, 1);
1164 	if (ret)
1165 		return ret;
1166 
1167 	if (configured)
1168 		val |= PORT_CS_19_PC;
1169 	else
1170 		val &= ~PORT_CS_19_PC;
1171 
1172 	return tb_port_write(port, &val, TB_CFG_PORT,
1173 			     port->cap_usb4 + PORT_CS_19, 1);
1174 }
1175 
1176 /**
1177  * usb4_port_configure() - Set USB4 port configured
1178  * @port: USB4 router
1179  *
1180  * Sets the USB4 link to be configured for power management purposes.
1181  */
1182 int usb4_port_configure(struct tb_port *port)
1183 {
1184 	return usb4_port_set_configured(port, true);
1185 }
1186 
1187 /**
1188  * usb4_port_unconfigure() - Set USB4 port unconfigured
1189  * @port: USB4 router
1190  *
1191  * Sets the USB4 link to be unconfigured for power management purposes.
1192  */
1193 void usb4_port_unconfigure(struct tb_port *port)
1194 {
1195 	usb4_port_set_configured(port, false);
1196 }
1197 
1198 static int usb4_set_xdomain_configured(struct tb_port *port, bool configured)
1199 {
1200 	int ret;
1201 	u32 val;
1202 
1203 	if (!port->cap_usb4)
1204 		return -EINVAL;
1205 
1206 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1207 			   port->cap_usb4 + PORT_CS_19, 1);
1208 	if (ret)
1209 		return ret;
1210 
1211 	if (configured)
1212 		val |= PORT_CS_19_PID;
1213 	else
1214 		val &= ~PORT_CS_19_PID;
1215 
1216 	return tb_port_write(port, &val, TB_CFG_PORT,
1217 			     port->cap_usb4 + PORT_CS_19, 1);
1218 }
1219 
1220 /**
1221  * usb4_port_configure_xdomain() - Configure port for XDomain
1222  * @port: USB4 port connected to another host
1223  * @xd: XDomain that is connected to the port
1224  *
1225  * Marks the USB4 port as being connected to another host and updates
1226  * the link type. Returns %0 in success and negative errno in failure.
1227  */
1228 int usb4_port_configure_xdomain(struct tb_port *port, struct tb_xdomain *xd)
1229 {
1230 	xd->link_usb4 = link_is_usb4(port);
1231 	return usb4_set_xdomain_configured(port, true);
1232 }
1233 
1234 /**
1235  * usb4_port_unconfigure_xdomain() - Unconfigure port for XDomain
1236  * @port: USB4 port that was connected to another host
1237  *
1238  * Clears USB4 port from being marked as XDomain.
1239  */
1240 void usb4_port_unconfigure_xdomain(struct tb_port *port)
1241 {
1242 	usb4_set_xdomain_configured(port, false);
1243 }
1244 
1245 static int usb4_port_wait_for_bit(struct tb_port *port, u32 offset, u32 bit,
1246 			  u32 value, int timeout_msec, unsigned long delay_usec)
1247 {
1248 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1249 
1250 	do {
1251 		u32 val;
1252 		int ret;
1253 
1254 		ret = tb_port_read(port, &val, TB_CFG_PORT, offset, 1);
1255 		if (ret)
1256 			return ret;
1257 
1258 		if ((val & bit) == value)
1259 			return 0;
1260 
1261 		fsleep(delay_usec);
1262 	} while (ktime_before(ktime_get(), timeout));
1263 
1264 	return -ETIMEDOUT;
1265 }
1266 
1267 static int usb4_port_read_data(struct tb_port *port, void *data, size_t dwords)
1268 {
1269 	if (dwords > USB4_DATA_DWORDS)
1270 		return -EINVAL;
1271 
1272 	return tb_port_read(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1273 			    dwords);
1274 }
1275 
1276 static int usb4_port_write_data(struct tb_port *port, const void *data,
1277 				size_t dwords)
1278 {
1279 	if (dwords > USB4_DATA_DWORDS)
1280 		return -EINVAL;
1281 
1282 	return tb_port_write(port, data, TB_CFG_PORT, port->cap_usb4 + PORT_CS_2,
1283 			     dwords);
1284 }
1285 
1286 /**
1287  * usb4_port_sb_read() - Read from sideband register
1288  * @port: USB4 port to read
1289  * @target: Sideband target
1290  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1291  * @reg: Sideband register index
1292  * @buf: Buffer where the sideband data is copied
1293  * @size: Size of @buf
1294  *
1295  * Reads data from sideband register @reg and copies it into @buf.
1296  * Returns %0 in case of success and negative errno in case of failure.
1297  */
1298 int usb4_port_sb_read(struct tb_port *port, enum usb4_sb_target target, u8 index,
1299 		      u8 reg, void *buf, u8 size)
1300 {
1301 	size_t dwords = DIV_ROUND_UP(size, 4);
1302 	int ret;
1303 	u32 val;
1304 
1305 	if (!port->cap_usb4)
1306 		return -EINVAL;
1307 
1308 	val = reg;
1309 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1310 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1311 	if (target == USB4_SB_TARGET_RETIMER)
1312 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1313 	val |= PORT_CS_1_PND;
1314 
1315 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1316 			    port->cap_usb4 + PORT_CS_1, 1);
1317 	if (ret)
1318 		return ret;
1319 
1320 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1321 				     PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
1322 	if (ret)
1323 		return ret;
1324 
1325 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1326 			    port->cap_usb4 + PORT_CS_1, 1);
1327 	if (ret)
1328 		return ret;
1329 
1330 	if (val & PORT_CS_1_NR)
1331 		return -ENODEV;
1332 	if (val & PORT_CS_1_RC)
1333 		return -EIO;
1334 
1335 	return buf ? usb4_port_read_data(port, buf, dwords) : 0;
1336 }
1337 
1338 /**
1339  * usb4_port_sb_write() - Write to sideband register
1340  * @port: USB4 port to write
1341  * @target: Sideband target
1342  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1343  * @reg: Sideband register index
1344  * @buf: Data to write
1345  * @size: Size of @buf
1346  *
1347  * Writes @buf to sideband register @reg. Returns %0 in case of success
1348  * and negative errno in case of failure.
1349  */
1350 int usb4_port_sb_write(struct tb_port *port, enum usb4_sb_target target,
1351 		       u8 index, u8 reg, const void *buf, u8 size)
1352 {
1353 	size_t dwords = DIV_ROUND_UP(size, 4);
1354 	int ret;
1355 	u32 val;
1356 
1357 	if (!port->cap_usb4)
1358 		return -EINVAL;
1359 
1360 	if (buf) {
1361 		ret = usb4_port_write_data(port, buf, dwords);
1362 		if (ret)
1363 			return ret;
1364 	}
1365 
1366 	val = reg;
1367 	val |= size << PORT_CS_1_LENGTH_SHIFT;
1368 	val |= PORT_CS_1_WNR_WRITE;
1369 	val |= (target << PORT_CS_1_TARGET_SHIFT) & PORT_CS_1_TARGET_MASK;
1370 	if (target == USB4_SB_TARGET_RETIMER)
1371 		val |= (index << PORT_CS_1_RETIMER_INDEX_SHIFT);
1372 	val |= PORT_CS_1_PND;
1373 
1374 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1375 			    port->cap_usb4 + PORT_CS_1, 1);
1376 	if (ret)
1377 		return ret;
1378 
1379 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_1,
1380 				     PORT_CS_1_PND, 0, 500, USB4_PORT_SB_DELAY);
1381 	if (ret)
1382 		return ret;
1383 
1384 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1385 			    port->cap_usb4 + PORT_CS_1, 1);
1386 	if (ret)
1387 		return ret;
1388 
1389 	if (val & PORT_CS_1_NR)
1390 		return -ENODEV;
1391 	if (val & PORT_CS_1_RC)
1392 		return -EIO;
1393 
1394 	return 0;
1395 }
1396 
1397 static int usb4_port_sb_opcode_err_to_errno(u32 val)
1398 {
1399 	switch (val) {
1400 	case 0:
1401 		return 0;
1402 	case USB4_SB_OPCODE_ERR:
1403 		return -EAGAIN;
1404 	case USB4_SB_OPCODE_ONS:
1405 		return -EOPNOTSUPP;
1406 	default:
1407 		return -EIO;
1408 	}
1409 }
1410 
1411 static int usb4_port_sb_op(struct tb_port *port, enum usb4_sb_target target,
1412 			   u8 index, enum usb4_sb_opcode opcode, int timeout_msec)
1413 {
1414 	ktime_t timeout;
1415 	u32 val;
1416 	int ret;
1417 
1418 	val = opcode;
1419 	ret = usb4_port_sb_write(port, target, index, USB4_SB_OPCODE, &val,
1420 				 sizeof(val));
1421 	if (ret)
1422 		return ret;
1423 
1424 	timeout = ktime_add_ms(ktime_get(), timeout_msec);
1425 
1426 	do {
1427 		/* Check results */
1428 		ret = usb4_port_sb_read(port, target, index, USB4_SB_OPCODE,
1429 					&val, sizeof(val));
1430 		if (ret)
1431 			return ret;
1432 
1433 		if (val != opcode)
1434 			return usb4_port_sb_opcode_err_to_errno(val);
1435 
1436 		fsleep(USB4_PORT_SB_DELAY);
1437 	} while (ktime_before(ktime_get(), timeout));
1438 
1439 	return -ETIMEDOUT;
1440 }
1441 
1442 static int usb4_port_set_router_offline(struct tb_port *port, bool offline)
1443 {
1444 	u32 val = !offline;
1445 	int ret;
1446 
1447 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1448 				  USB4_SB_METADATA, &val, sizeof(val));
1449 	if (ret)
1450 		return ret;
1451 
1452 	val = USB4_SB_OPCODE_ROUTER_OFFLINE;
1453 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1454 				  USB4_SB_OPCODE, &val, sizeof(val));
1455 }
1456 
1457 /**
1458  * usb4_port_router_offline() - Put the USB4 port to offline mode
1459  * @port: USB4 port
1460  *
1461  * This function puts the USB4 port into offline mode. In this mode the
1462  * port does not react on hotplug events anymore. This needs to be
1463  * called before retimer access is done when the USB4 links is not up.
1464  *
1465  * Returns %0 in case of success and negative errno if there was an
1466  * error.
1467  */
1468 int usb4_port_router_offline(struct tb_port *port)
1469 {
1470 	return usb4_port_set_router_offline(port, true);
1471 }
1472 
1473 /**
1474  * usb4_port_router_online() - Put the USB4 port back to online
1475  * @port: USB4 port
1476  *
1477  * Makes the USB4 port functional again.
1478  */
1479 int usb4_port_router_online(struct tb_port *port)
1480 {
1481 	return usb4_port_set_router_offline(port, false);
1482 }
1483 
1484 /**
1485  * usb4_port_enumerate_retimers() - Send RT broadcast transaction
1486  * @port: USB4 port
1487  *
1488  * This forces the USB4 port to send broadcast RT transaction which
1489  * makes the retimers on the link to assign index to themselves. Returns
1490  * %0 in case of success and negative errno if there was an error.
1491  */
1492 int usb4_port_enumerate_retimers(struct tb_port *port)
1493 {
1494 	u32 val;
1495 
1496 	val = USB4_SB_OPCODE_ENUMERATE_RETIMERS;
1497 	return usb4_port_sb_write(port, USB4_SB_TARGET_ROUTER, 0,
1498 				  USB4_SB_OPCODE, &val, sizeof(val));
1499 }
1500 
1501 /**
1502  * usb4_port_clx_supported() - Check if CLx is supported by the link
1503  * @port: Port to check for CLx support for
1504  *
1505  * PORT_CS_18_CPS bit reflects if the link supports CLx including
1506  * active cables (if connected on the link).
1507  */
1508 bool usb4_port_clx_supported(struct tb_port *port)
1509 {
1510 	int ret;
1511 	u32 val;
1512 
1513 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1514 			   port->cap_usb4 + PORT_CS_18, 1);
1515 	if (ret)
1516 		return false;
1517 
1518 	return !!(val & PORT_CS_18_CPS);
1519 }
1520 
1521 /**
1522  * usb4_port_asym_supported() - If the port supports asymmetric link
1523  * @port: USB4 port
1524  *
1525  * Checks if the port and the cable supports asymmetric link and returns
1526  * %true in that case.
1527  */
1528 bool usb4_port_asym_supported(struct tb_port *port)
1529 {
1530 	u32 val;
1531 
1532 	if (!port->cap_usb4)
1533 		return false;
1534 
1535 	if (tb_port_read(port, &val, TB_CFG_PORT, port->cap_usb4 + PORT_CS_18, 1))
1536 		return false;
1537 
1538 	return !!(val & PORT_CS_18_CSA);
1539 }
1540 
1541 /**
1542  * usb4_port_asym_set_link_width() - Set link width to asymmetric or symmetric
1543  * @port: USB4 port
1544  * @width: Asymmetric width to configure
1545  *
1546  * Sets USB4 port link width to @width. Can be called for widths where
1547  * usb4_port_asym_width_supported() returned @true.
1548  */
1549 int usb4_port_asym_set_link_width(struct tb_port *port, enum tb_link_width width)
1550 {
1551 	u32 val;
1552 	int ret;
1553 
1554 	if (!port->cap_phy)
1555 		return -EINVAL;
1556 
1557 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1558 			   port->cap_phy + LANE_ADP_CS_1, 1);
1559 	if (ret)
1560 		return ret;
1561 
1562 	val &= ~LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK;
1563 	switch (width) {
1564 	case TB_LINK_WIDTH_DUAL:
1565 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1566 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_DUAL);
1567 		break;
1568 	case TB_LINK_WIDTH_ASYM_TX:
1569 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1570 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_TX);
1571 		break;
1572 	case TB_LINK_WIDTH_ASYM_RX:
1573 		val |= FIELD_PREP(LANE_ADP_CS_1_TARGET_WIDTH_ASYM_MASK,
1574 				  LANE_ADP_CS_1_TARGET_WIDTH_ASYM_RX);
1575 		break;
1576 	default:
1577 		return -EINVAL;
1578 	}
1579 
1580 	return tb_port_write(port, &val, TB_CFG_PORT,
1581 			     port->cap_phy + LANE_ADP_CS_1, 1);
1582 }
1583 
1584 /**
1585  * usb4_port_asym_start() - Start symmetry change and wait for completion
1586  * @port: USB4 port
1587  *
1588  * Start symmetry change of the link to asymmetric or symmetric
1589  * (according to what was previously set in tb_port_set_link_width().
1590  * Wait for completion of the change.
1591  *
1592  * Returns %0 in case of success, %-ETIMEDOUT if case of timeout or
1593  * a negative errno in case of a failure.
1594  */
1595 int usb4_port_asym_start(struct tb_port *port)
1596 {
1597 	int ret;
1598 	u32 val;
1599 
1600 	ret = tb_port_read(port, &val, TB_CFG_PORT,
1601 			   port->cap_usb4 + PORT_CS_19, 1);
1602 	if (ret)
1603 		return ret;
1604 
1605 	val &= ~PORT_CS_19_START_ASYM;
1606 	val |= FIELD_PREP(PORT_CS_19_START_ASYM, 1);
1607 
1608 	ret = tb_port_write(port, &val, TB_CFG_PORT,
1609 			    port->cap_usb4 + PORT_CS_19, 1);
1610 	if (ret)
1611 		return ret;
1612 
1613 	/*
1614 	 * Wait for PORT_CS_19_START_ASYM to be 0. This means the USB4
1615 	 * port started the symmetry transition.
1616 	 */
1617 	ret = usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_19,
1618 				     PORT_CS_19_START_ASYM, 0, 1000,
1619 				     USB4_PORT_DELAY);
1620 	if (ret)
1621 		return ret;
1622 
1623 	/* Then wait for the transtion to be completed */
1624 	return usb4_port_wait_for_bit(port, port->cap_usb4 + PORT_CS_18,
1625 				      PORT_CS_18_TIP, 0, 5000, USB4_PORT_DELAY);
1626 }
1627 
1628 /**
1629  * usb4_port_margining_caps() - Read USB4 port marginig capabilities
1630  * @port: USB4 port
1631  * @target: Sideband target
1632  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1633  * @caps: Array with at least two elements to hold the results
1634  *
1635  * Reads the USB4 port lane margining capabilities into @caps.
1636  */
1637 int usb4_port_margining_caps(struct tb_port *port, enum usb4_sb_target target,
1638 			     u8 index, u32 *caps)
1639 {
1640 	int ret;
1641 
1642 	ret = usb4_port_sb_op(port, target, index,
1643 			      USB4_SB_OPCODE_READ_LANE_MARGINING_CAP, 500);
1644 	if (ret)
1645 		return ret;
1646 
1647 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, caps,
1648 				 sizeof(*caps) * 2);
1649 }
1650 
1651 /**
1652  * usb4_port_hw_margin() - Run hardware lane margining on port
1653  * @port: USB4 port
1654  * @target: Sideband target
1655  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1656  * @lanes: Which lanes to run (must match the port capabilities). Can be
1657  *	   %0, %1 or %7.
1658  * @ber_level: BER level contour value
1659  * @timing: Perform timing margining instead of voltage
1660  * @right_high: Use Right/high margin instead of left/low
1661  * @results: Array with at least two elements to hold the results
1662  *
1663  * Runs hardware lane margining on USB4 port and returns the result in
1664  * @results.
1665  */
1666 int usb4_port_hw_margin(struct tb_port *port, enum usb4_sb_target target,
1667 			u8 index, unsigned int lanes, unsigned int ber_level,
1668 			bool timing, bool right_high, u32 *results)
1669 {
1670 	u32 val;
1671 	int ret;
1672 
1673 	val = lanes;
1674 	if (timing)
1675 		val |= USB4_MARGIN_HW_TIME;
1676 	if (right_high)
1677 		val |= USB4_MARGIN_HW_RH;
1678 	if (ber_level)
1679 		val |= (ber_level << USB4_MARGIN_HW_BER_SHIFT) &
1680 			USB4_MARGIN_HW_BER_MASK;
1681 
1682 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1683 				 sizeof(val));
1684 	if (ret)
1685 		return ret;
1686 
1687 	ret = usb4_port_sb_op(port, target, index,
1688 			      USB4_SB_OPCODE_RUN_HW_LANE_MARGINING, 2500);
1689 	if (ret)
1690 		return ret;
1691 
1692 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, results,
1693 				 sizeof(*results) * 2);
1694 }
1695 
1696 /**
1697  * usb4_port_sw_margin() - Run software lane margining on port
1698  * @port: USB4 port
1699  * @target: Sideband target
1700  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1701  * @lanes: Which lanes to run (must match the port capabilities). Can be
1702  *	   %0, %1 or %7.
1703  * @timing: Perform timing margining instead of voltage
1704  * @right_high: Use Right/high margin instead of left/low
1705  * @counter: What to do with the error counter
1706  *
1707  * Runs software lane margining on USB4 port. Read back the error
1708  * counters by calling usb4_port_sw_margin_errors(). Returns %0 in
1709  * success and negative errno otherwise.
1710  */
1711 int usb4_port_sw_margin(struct tb_port *port, enum usb4_sb_target target,
1712 			u8 index, unsigned int lanes, bool timing,
1713 			bool right_high, u32 counter)
1714 {
1715 	u32 val;
1716 	int ret;
1717 
1718 	val = lanes;
1719 	if (timing)
1720 		val |= USB4_MARGIN_SW_TIME;
1721 	if (right_high)
1722 		val |= USB4_MARGIN_SW_RH;
1723 	val |= (counter << USB4_MARGIN_SW_COUNTER_SHIFT) &
1724 		USB4_MARGIN_SW_COUNTER_MASK;
1725 
1726 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1727 				 sizeof(val));
1728 	if (ret)
1729 		return ret;
1730 
1731 	return usb4_port_sb_op(port, target, index,
1732 			       USB4_SB_OPCODE_RUN_SW_LANE_MARGINING, 2500);
1733 }
1734 
1735 /**
1736  * usb4_port_sw_margin_errors() - Read the software margining error counters
1737  * @port: USB4 port
1738  * @target: Sideband target
1739  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1740  * @errors: Error metadata is copied here.
1741  *
1742  * This reads back the software margining error counters from the port.
1743  * Returns %0 in success and negative errno otherwise.
1744  */
1745 int usb4_port_sw_margin_errors(struct tb_port *port, enum usb4_sb_target target,
1746 			       u8 index, u32 *errors)
1747 {
1748 	int ret;
1749 
1750 	ret = usb4_port_sb_op(port, target, index,
1751 			      USB4_SB_OPCODE_READ_SW_MARGIN_ERR, 150);
1752 	if (ret)
1753 		return ret;
1754 
1755 	return usb4_port_sb_read(port, target, index, USB4_SB_METADATA, errors,
1756 				 sizeof(*errors));
1757 }
1758 
1759 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1760 				       enum usb4_sb_opcode opcode,
1761 				       int timeout_msec)
1762 {
1763 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1764 			       timeout_msec);
1765 }
1766 
1767 /**
1768  * usb4_port_retimer_set_inbound_sbtx() - Enable sideband channel transactions
1769  * @port: USB4 port
1770  * @index: Retimer index
1771  *
1772  * Enables sideband channel transations on SBTX. Can be used when USB4
1773  * link does not go up, for example if there is no device connected.
1774  */
1775 int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
1776 {
1777 	int ret;
1778 
1779 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1780 				   500);
1781 
1782 	if (ret != -ENODEV)
1783 		return ret;
1784 
1785 	/*
1786 	 * Per the USB4 retimer spec, the retimer is not required to
1787 	 * send an RT (Retimer Transaction) response for the first
1788 	 * SET_INBOUND_SBTX command
1789 	 */
1790 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1791 				    500);
1792 }
1793 
1794 /**
1795  * usb4_port_retimer_unset_inbound_sbtx() - Disable sideband channel transactions
1796  * @port: USB4 port
1797  * @index: Retimer index
1798  *
1799  * Disables sideband channel transations on SBTX. The reverse of
1800  * usb4_port_retimer_set_inbound_sbtx().
1801  */
1802 int usb4_port_retimer_unset_inbound_sbtx(struct tb_port *port, u8 index)
1803 {
1804 	return usb4_port_retimer_op(port, index,
1805 				    USB4_SB_OPCODE_UNSET_INBOUND_SBTX, 500);
1806 }
1807 
1808 /**
1809  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1810  * @port: USB4 port
1811  * @index: Retimer index
1812  *
1813  * If the retimer at @index is last one (connected directly to the
1814  * Type-C port) this function returns %1. If it is not returns %0. If
1815  * the retimer is not present returns %-ENODEV. Otherwise returns
1816  * negative errno.
1817  */
1818 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1819 {
1820 	u32 metadata;
1821 	int ret;
1822 
1823 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1824 				   500);
1825 	if (ret)
1826 		return ret;
1827 
1828 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1829 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1830 	return ret ? ret : metadata & 1;
1831 }
1832 
1833 /**
1834  * usb4_port_retimer_is_cable() - Is the retimer cable retimer
1835  * @port: USB4 port
1836  * @index: Retimer index
1837  *
1838  * If the retimer at @index is last cable retimer this function returns
1839  * %1 and %0 if it is on-board retimer. In case a retimer is not present
1840  * at @index returns %-ENODEV. Otherwise returns negative errno.
1841  */
1842 int usb4_port_retimer_is_cable(struct tb_port *port, u8 index)
1843 {
1844 	u32 metadata;
1845 	int ret;
1846 
1847 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_CABLE_RETIMER,
1848 				   500);
1849 	if (ret)
1850 		return ret;
1851 
1852 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1853 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1854 	return ret ? ret : metadata & 1;
1855 }
1856 
1857 /**
1858  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1859  * @port: USB4 port
1860  * @index: Retimer index
1861  *
1862  * Reads NVM sector size (in bytes) of a retimer at @index. This
1863  * operation can be used to determine whether the retimer supports NVM
1864  * upgrade for example. Returns sector size in bytes or negative errno
1865  * in case of error. Specifically returns %-ENODEV if there is no
1866  * retimer at @index.
1867  */
1868 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1869 {
1870 	u32 metadata;
1871 	int ret;
1872 
1873 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1874 				   500);
1875 	if (ret)
1876 		return ret;
1877 
1878 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1879 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1880 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1881 }
1882 
1883 /**
1884  * usb4_port_retimer_nvm_set_offset() - Set NVM write offset
1885  * @port: USB4 port
1886  * @index: Retimer index
1887  * @address: Start offset
1888  *
1889  * Exlicitly sets NVM write offset. Normally when writing to NVM this is
1890  * done automatically by usb4_port_retimer_nvm_write().
1891  *
1892  * Returns %0 in success and negative errno if there was a failure.
1893  */
1894 int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1895 				     unsigned int address)
1896 {
1897 	u32 metadata, dwaddress;
1898 	int ret;
1899 
1900 	dwaddress = address / 4;
1901 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1902 		  USB4_NVM_SET_OFFSET_MASK;
1903 
1904 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1905 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
1906 	if (ret)
1907 		return ret;
1908 
1909 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1910 				    500);
1911 }
1912 
1913 struct retimer_info {
1914 	struct tb_port *port;
1915 	u8 index;
1916 };
1917 
1918 static int usb4_port_retimer_nvm_write_next_block(void *data,
1919 	unsigned int dwaddress, const void *buf, size_t dwords)
1920 
1921 {
1922 	const struct retimer_info *info = data;
1923 	struct tb_port *port = info->port;
1924 	u8 index = info->index;
1925 	int ret;
1926 
1927 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1928 				 USB4_SB_DATA, buf, dwords * 4);
1929 	if (ret)
1930 		return ret;
1931 
1932 	return usb4_port_retimer_op(port, index,
1933 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1934 }
1935 
1936 /**
1937  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1938  * @port: USB4 port
1939  * @index: Retimer index
1940  * @address: Byte address where to start the write
1941  * @buf: Data to write
1942  * @size: Size in bytes how much to write
1943  *
1944  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1945  * upgrade. Returns %0 if the data was written successfully and negative
1946  * errno in case of failure. Specifically returns %-ENODEV if there is
1947  * no retimer at @index.
1948  */
1949 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1950 				const void *buf, size_t size)
1951 {
1952 	struct retimer_info info = { .port = port, .index = index };
1953 	int ret;
1954 
1955 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1956 	if (ret)
1957 		return ret;
1958 
1959 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
1960 				 usb4_port_retimer_nvm_write_next_block, &info);
1961 }
1962 
1963 /**
1964  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1965  * @port: USB4 port
1966  * @index: Retimer index
1967  *
1968  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1969  * this function can be used to trigger the NVM upgrade process. If
1970  * successful the retimer restarts with the new NVM and may not have the
1971  * index set so one needs to call usb4_port_enumerate_retimers() to
1972  * force index to be assigned.
1973  */
1974 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1975 {
1976 	u32 val;
1977 
1978 	/*
1979 	 * We need to use the raw operation here because once the
1980 	 * authentication completes the retimer index is not set anymore
1981 	 * so we do not get back the status now.
1982 	 */
1983 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1984 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1985 				  USB4_SB_OPCODE, &val, sizeof(val));
1986 }
1987 
1988 /**
1989  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
1990  * @port: USB4 port
1991  * @index: Retimer index
1992  * @status: Raw status code read from metadata
1993  *
1994  * This can be called after usb4_port_retimer_nvm_authenticate() and
1995  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
1996  *
1997  * Returns %0 if the authentication status was successfully read. The
1998  * completion metadata (the result) is then stored into @status. If
1999  * reading the status fails, returns negative errno.
2000  */
2001 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
2002 					      u32 *status)
2003 {
2004 	u32 metadata, val;
2005 	int ret;
2006 
2007 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2008 				USB4_SB_OPCODE, &val, sizeof(val));
2009 	if (ret)
2010 		return ret;
2011 
2012 	ret = usb4_port_sb_opcode_err_to_errno(val);
2013 	switch (ret) {
2014 	case 0:
2015 		*status = 0;
2016 		return 0;
2017 
2018 	case -EAGAIN:
2019 		ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2020 					USB4_SB_METADATA, &metadata,
2021 					sizeof(metadata));
2022 		if (ret)
2023 			return ret;
2024 
2025 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
2026 		return 0;
2027 
2028 	default:
2029 		return ret;
2030 	}
2031 }
2032 
2033 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
2034 					    void *buf, size_t dwords)
2035 {
2036 	const struct retimer_info *info = data;
2037 	struct tb_port *port = info->port;
2038 	u8 index = info->index;
2039 	u32 metadata;
2040 	int ret;
2041 
2042 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
2043 	if (dwords < USB4_DATA_DWORDS)
2044 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
2045 
2046 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2047 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
2048 	if (ret)
2049 		return ret;
2050 
2051 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
2052 	if (ret)
2053 		return ret;
2054 
2055 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2056 				 USB4_SB_DATA, buf, dwords * 4);
2057 }
2058 
2059 /**
2060  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
2061  * @port: USB4 port
2062  * @index: Retimer index
2063  * @address: NVM address (in bytes) to start reading
2064  * @buf: Data read from NVM is stored here
2065  * @size: Number of bytes to read
2066  *
2067  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
2068  * read was successful and negative errno in case of failure.
2069  * Specifically returns %-ENODEV if there is no retimer at @index.
2070  */
2071 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
2072 			       unsigned int address, void *buf, size_t size)
2073 {
2074 	struct retimer_info info = { .port = port, .index = index };
2075 
2076 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
2077 				usb4_port_retimer_nvm_read_block, &info);
2078 }
2079 
2080 static inline unsigned int
2081 usb4_usb3_port_max_bandwidth(const struct tb_port *port, unsigned int bw)
2082 {
2083 	/* Take the possible bandwidth limitation into account */
2084 	if (port->max_bw)
2085 		return min(bw, port->max_bw);
2086 	return bw;
2087 }
2088 
2089 /**
2090  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
2091  * @port: USB3 adapter port
2092  *
2093  * Return maximum supported link rate of a USB3 adapter in Mb/s.
2094  * Negative errno in case of error.
2095  */
2096 int usb4_usb3_port_max_link_rate(struct tb_port *port)
2097 {
2098 	int ret, lr;
2099 	u32 val;
2100 
2101 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
2102 		return -EINVAL;
2103 
2104 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2105 			   port->cap_adap + ADP_USB3_CS_4, 1);
2106 	if (ret)
2107 		return ret;
2108 
2109 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
2110 	ret = lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
2111 
2112 	return usb4_usb3_port_max_bandwidth(port, ret);
2113 }
2114 
2115 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
2116 {
2117 	int ret;
2118 	u32 val;
2119 
2120 	if (!tb_port_is_usb3_down(port))
2121 		return -EINVAL;
2122 	if (tb_route(port->sw))
2123 		return -EINVAL;
2124 
2125 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2126 			   port->cap_adap + ADP_USB3_CS_2, 1);
2127 	if (ret)
2128 		return ret;
2129 
2130 	if (request)
2131 		val |= ADP_USB3_CS_2_CMR;
2132 	else
2133 		val &= ~ADP_USB3_CS_2_CMR;
2134 
2135 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2136 			    port->cap_adap + ADP_USB3_CS_2, 1);
2137 	if (ret)
2138 		return ret;
2139 
2140 	/*
2141 	 * We can use val here directly as the CMR bit is in the same place
2142 	 * as HCA. Just mask out others.
2143 	 */
2144 	val &= ADP_USB3_CS_2_CMR;
2145 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
2146 				      ADP_USB3_CS_1_HCA, val, 1500,
2147 				      USB4_PORT_DELAY);
2148 }
2149 
2150 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
2151 {
2152 	return usb4_usb3_port_cm_request(port, true);
2153 }
2154 
2155 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
2156 {
2157 	return usb4_usb3_port_cm_request(port, false);
2158 }
2159 
2160 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
2161 {
2162 	unsigned long uframes;
2163 
2164 	uframes = bw * 512UL << scale;
2165 	return DIV_ROUND_CLOSEST(uframes * 8000, MEGA);
2166 }
2167 
2168 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
2169 {
2170 	unsigned long uframes;
2171 
2172 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
2173 	uframes = ((unsigned long)mbps * MEGA) / 8000;
2174 	return DIV_ROUND_UP(uframes, 512UL << scale);
2175 }
2176 
2177 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
2178 						   int *upstream_bw,
2179 						   int *downstream_bw)
2180 {
2181 	u32 val, bw, scale;
2182 	int ret;
2183 
2184 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2185 			   port->cap_adap + ADP_USB3_CS_2, 1);
2186 	if (ret)
2187 		return ret;
2188 
2189 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2190 			   port->cap_adap + ADP_USB3_CS_3, 1);
2191 	if (ret)
2192 		return ret;
2193 
2194 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2195 
2196 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
2197 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2198 
2199 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
2200 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2201 
2202 	return 0;
2203 }
2204 
2205 /**
2206  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
2207  * @port: USB3 adapter port
2208  * @upstream_bw: Allocated upstream bandwidth is stored here
2209  * @downstream_bw: Allocated downstream bandwidth is stored here
2210  *
2211  * Stores currently allocated USB3 bandwidth into @upstream_bw and
2212  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
2213  * errno in failure.
2214  */
2215 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
2216 				       int *downstream_bw)
2217 {
2218 	int ret;
2219 
2220 	ret = usb4_usb3_port_set_cm_request(port);
2221 	if (ret)
2222 		return ret;
2223 
2224 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
2225 						      downstream_bw);
2226 	usb4_usb3_port_clear_cm_request(port);
2227 
2228 	return ret;
2229 }
2230 
2231 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
2232 						  int *upstream_bw,
2233 						  int *downstream_bw)
2234 {
2235 	u32 val, bw, scale;
2236 	int ret;
2237 
2238 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2239 			   port->cap_adap + ADP_USB3_CS_1, 1);
2240 	if (ret)
2241 		return ret;
2242 
2243 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2244 			   port->cap_adap + ADP_USB3_CS_3, 1);
2245 	if (ret)
2246 		return ret;
2247 
2248 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2249 
2250 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
2251 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2252 
2253 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
2254 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2255 
2256 	return 0;
2257 }
2258 
2259 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
2260 						    int upstream_bw,
2261 						    int downstream_bw)
2262 {
2263 	u32 val, ubw, dbw, scale;
2264 	int ret, max_bw;
2265 
2266 	/* Figure out suitable scale */
2267 	scale = 0;
2268 	max_bw = max(upstream_bw, downstream_bw);
2269 	while (scale < 64) {
2270 		if (mbps_to_usb3_bw(max_bw, scale) < 4096)
2271 			break;
2272 		scale++;
2273 	}
2274 
2275 	if (WARN_ON(scale >= 64))
2276 		return -EINVAL;
2277 
2278 	ret = tb_port_write(port, &scale, TB_CFG_PORT,
2279 			    port->cap_adap + ADP_USB3_CS_3, 1);
2280 	if (ret)
2281 		return ret;
2282 
2283 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
2284 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
2285 
2286 	tb_port_dbg(port, "scaled bandwidth %u/%u, scale %u\n", ubw, dbw, scale);
2287 
2288 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2289 			   port->cap_adap + ADP_USB3_CS_2, 1);
2290 	if (ret)
2291 		return ret;
2292 
2293 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
2294 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
2295 	val |= ubw;
2296 
2297 	return tb_port_write(port, &val, TB_CFG_PORT,
2298 			     port->cap_adap + ADP_USB3_CS_2, 1);
2299 }
2300 
2301 /**
2302  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
2303  * @port: USB3 adapter port
2304  * @upstream_bw: New upstream bandwidth
2305  * @downstream_bw: New downstream bandwidth
2306  *
2307  * This can be used to set how much bandwidth is allocated for the USB3
2308  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
2309  * new values programmed to the USB3 adapter allocation registers. If
2310  * the values are lower than what is currently consumed the allocation
2311  * is set to what is currently consumed instead (consumed bandwidth
2312  * cannot be taken away by CM). The actual new values are returned in
2313  * @upstream_bw and @downstream_bw.
2314  *
2315  * Returns %0 in case of success and negative errno if there was a
2316  * failure.
2317  */
2318 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
2319 				      int *downstream_bw)
2320 {
2321 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
2322 
2323 	ret = usb4_usb3_port_set_cm_request(port);
2324 	if (ret)
2325 		return ret;
2326 
2327 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2328 						     &consumed_down);
2329 	if (ret)
2330 		goto err_request;
2331 
2332 	/* Don't allow it go lower than what is consumed */
2333 	allocate_up = max(*upstream_bw, consumed_up);
2334 	allocate_down = max(*downstream_bw, consumed_down);
2335 
2336 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
2337 						       allocate_down);
2338 	if (ret)
2339 		goto err_request;
2340 
2341 	*upstream_bw = allocate_up;
2342 	*downstream_bw = allocate_down;
2343 
2344 err_request:
2345 	usb4_usb3_port_clear_cm_request(port);
2346 	return ret;
2347 }
2348 
2349 /**
2350  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
2351  * @port: USB3 adapter port
2352  * @upstream_bw: New allocated upstream bandwidth
2353  * @downstream_bw: New allocated downstream bandwidth
2354  *
2355  * Releases USB3 allocated bandwidth down to what is actually consumed.
2356  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
2357  *
2358  * Returns 0% in success and negative errno in case of failure.
2359  */
2360 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
2361 				     int *downstream_bw)
2362 {
2363 	int ret, consumed_up, consumed_down;
2364 
2365 	ret = usb4_usb3_port_set_cm_request(port);
2366 	if (ret)
2367 		return ret;
2368 
2369 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2370 						     &consumed_down);
2371 	if (ret)
2372 		goto err_request;
2373 
2374 	/*
2375 	 * Always keep 900 Mb/s to make sure xHCI has at least some
2376 	 * bandwidth available for isochronous traffic.
2377 	 */
2378 	if (consumed_up < 900)
2379 		consumed_up = 900;
2380 	if (consumed_down < 900)
2381 		consumed_down = 900;
2382 
2383 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
2384 						       consumed_down);
2385 	if (ret)
2386 		goto err_request;
2387 
2388 	*upstream_bw = consumed_up;
2389 	*downstream_bw = consumed_down;
2390 
2391 err_request:
2392 	usb4_usb3_port_clear_cm_request(port);
2393 	return ret;
2394 }
2395 
2396 static bool is_usb4_dpin(const struct tb_port *port)
2397 {
2398 	if (!tb_port_is_dpin(port))
2399 		return false;
2400 	if (!tb_switch_is_usb4(port->sw))
2401 		return false;
2402 	return true;
2403 }
2404 
2405 /**
2406  * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
2407  * @port: DP IN adapter
2408  * @cm_id: CM ID to assign
2409  *
2410  * Sets CM ID for the @port. Returns %0 on success and negative errno
2411  * otherwise. Speficially returns %-EOPNOTSUPP if the @port does not
2412  * support this.
2413  */
2414 int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
2415 {
2416 	u32 val;
2417 	int ret;
2418 
2419 	if (!is_usb4_dpin(port))
2420 		return -EOPNOTSUPP;
2421 
2422 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2423 			   port->cap_adap + ADP_DP_CS_2, 1);
2424 	if (ret)
2425 		return ret;
2426 
2427 	val &= ~ADP_DP_CS_2_CM_ID_MASK;
2428 	val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
2429 
2430 	return tb_port_write(port, &val, TB_CFG_PORT,
2431 			     port->cap_adap + ADP_DP_CS_2, 1);
2432 }
2433 
2434 /**
2435  * usb4_dp_port_bandwidth_mode_supported() - Is the bandwidth allocation mode
2436  *					     supported
2437  * @port: DP IN adapter to check
2438  *
2439  * Can be called to any DP IN adapter. Returns true if the adapter
2440  * supports USB4 bandwidth allocation mode, false otherwise.
2441  */
2442 bool usb4_dp_port_bandwidth_mode_supported(struct tb_port *port)
2443 {
2444 	int ret;
2445 	u32 val;
2446 
2447 	if (!is_usb4_dpin(port))
2448 		return false;
2449 
2450 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2451 			   port->cap_adap + DP_LOCAL_CAP, 1);
2452 	if (ret)
2453 		return false;
2454 
2455 	return !!(val & DP_COMMON_CAP_BW_MODE);
2456 }
2457 
2458 /**
2459  * usb4_dp_port_bandwidth_mode_enabled() - Is the bandwidth allocation mode
2460  *					   enabled
2461  * @port: DP IN adapter to check
2462  *
2463  * Can be called to any DP IN adapter. Returns true if the bandwidth
2464  * allocation mode has been enabled, false otherwise.
2465  */
2466 bool usb4_dp_port_bandwidth_mode_enabled(struct tb_port *port)
2467 {
2468 	int ret;
2469 	u32 val;
2470 
2471 	if (!is_usb4_dpin(port))
2472 		return false;
2473 
2474 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2475 			   port->cap_adap + ADP_DP_CS_8, 1);
2476 	if (ret)
2477 		return false;
2478 
2479 	return !!(val & ADP_DP_CS_8_DPME);
2480 }
2481 
2482 /**
2483  * usb4_dp_port_set_cm_bandwidth_mode_supported() - Set/clear CM support for
2484  *						    bandwidth allocation mode
2485  * @port: DP IN adapter
2486  * @supported: Does the CM support bandwidth allocation mode
2487  *
2488  * Can be called to any DP IN adapter. Sets or clears the CM support bit
2489  * of the DP IN adapter. Returns %0 in success and negative errno
2490  * otherwise. Specifically returns %-OPNOTSUPP if the passed in adapter
2491  * does not support this.
2492  */
2493 int usb4_dp_port_set_cm_bandwidth_mode_supported(struct tb_port *port,
2494 						 bool supported)
2495 {
2496 	u32 val;
2497 	int ret;
2498 
2499 	if (!is_usb4_dpin(port))
2500 		return -EOPNOTSUPP;
2501 
2502 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2503 			   port->cap_adap + ADP_DP_CS_2, 1);
2504 	if (ret)
2505 		return ret;
2506 
2507 	if (supported)
2508 		val |= ADP_DP_CS_2_CMMS;
2509 	else
2510 		val &= ~ADP_DP_CS_2_CMMS;
2511 
2512 	return tb_port_write(port, &val, TB_CFG_PORT,
2513 			     port->cap_adap + ADP_DP_CS_2, 1);
2514 }
2515 
2516 /**
2517  * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
2518  * @port: DP IN adapter
2519  *
2520  * Reads bandwidth allocation Group ID from the DP IN adapter and
2521  * returns it. If the adapter does not support setting Group_ID
2522  * %-EOPNOTSUPP is returned.
2523  */
2524 int usb4_dp_port_group_id(struct tb_port *port)
2525 {
2526 	u32 val;
2527 	int ret;
2528 
2529 	if (!is_usb4_dpin(port))
2530 		return -EOPNOTSUPP;
2531 
2532 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2533 			   port->cap_adap + ADP_DP_CS_2, 1);
2534 	if (ret)
2535 		return ret;
2536 
2537 	return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
2538 }
2539 
2540 /**
2541  * usb4_dp_port_set_group_id() - Set adapter Group ID
2542  * @port: DP IN adapter
2543  * @group_id: Group ID for the adapter
2544  *
2545  * Sets bandwidth allocation mode Group ID for the DP IN adapter.
2546  * Returns %0 in case of success and negative errno otherwise.
2547  * Specifically returns %-EOPNOTSUPP if the adapter does not support
2548  * this.
2549  */
2550 int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
2551 {
2552 	u32 val;
2553 	int ret;
2554 
2555 	if (!is_usb4_dpin(port))
2556 		return -EOPNOTSUPP;
2557 
2558 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2559 			   port->cap_adap + ADP_DP_CS_2, 1);
2560 	if (ret)
2561 		return ret;
2562 
2563 	val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
2564 	val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
2565 
2566 	return tb_port_write(port, &val, TB_CFG_PORT,
2567 			     port->cap_adap + ADP_DP_CS_2, 1);
2568 }
2569 
2570 /**
2571  * usb4_dp_port_nrd() - Read non-reduced rate and lanes
2572  * @port: DP IN adapter
2573  * @rate: Non-reduced rate in Mb/s is placed here
2574  * @lanes: Non-reduced lanes are placed here
2575  *
2576  * Reads the non-reduced rate and lanes from the DP IN adapter. Returns
2577  * %0 in success and negative errno otherwise. Specifically returns
2578  * %-EOPNOTSUPP if the adapter does not support this.
2579  */
2580 int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
2581 {
2582 	u32 val, tmp;
2583 	int ret;
2584 
2585 	if (!is_usb4_dpin(port))
2586 		return -EOPNOTSUPP;
2587 
2588 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2589 			   port->cap_adap + ADP_DP_CS_2, 1);
2590 	if (ret)
2591 		return ret;
2592 
2593 	tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
2594 	switch (tmp) {
2595 	case DP_COMMON_CAP_RATE_RBR:
2596 		*rate = 1620;
2597 		break;
2598 	case DP_COMMON_CAP_RATE_HBR:
2599 		*rate = 2700;
2600 		break;
2601 	case DP_COMMON_CAP_RATE_HBR2:
2602 		*rate = 5400;
2603 		break;
2604 	case DP_COMMON_CAP_RATE_HBR3:
2605 		*rate = 8100;
2606 		break;
2607 	}
2608 
2609 	tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
2610 	switch (tmp) {
2611 	case DP_COMMON_CAP_1_LANE:
2612 		*lanes = 1;
2613 		break;
2614 	case DP_COMMON_CAP_2_LANES:
2615 		*lanes = 2;
2616 		break;
2617 	case DP_COMMON_CAP_4_LANES:
2618 		*lanes = 4;
2619 		break;
2620 	}
2621 
2622 	return 0;
2623 }
2624 
2625 /**
2626  * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
2627  * @port: DP IN adapter
2628  * @rate: Non-reduced rate in Mb/s
2629  * @lanes: Non-reduced lanes
2630  *
2631  * Before the capabilities reduction this function can be used to set
2632  * the non-reduced values for the DP IN adapter. Returns %0 in success
2633  * and negative errno otherwise. If the adapter does not support this
2634  * %-EOPNOTSUPP is returned.
2635  */
2636 int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
2637 {
2638 	u32 val;
2639 	int ret;
2640 
2641 	if (!is_usb4_dpin(port))
2642 		return -EOPNOTSUPP;
2643 
2644 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2645 			   port->cap_adap + ADP_DP_CS_2, 1);
2646 	if (ret)
2647 		return ret;
2648 
2649 	val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
2650 
2651 	switch (rate) {
2652 	case 1620:
2653 		break;
2654 	case 2700:
2655 		val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
2656 			& ADP_DP_CS_2_NRD_MLR_MASK;
2657 		break;
2658 	case 5400:
2659 		val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2660 			& ADP_DP_CS_2_NRD_MLR_MASK;
2661 		break;
2662 	case 8100:
2663 		val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2664 			& ADP_DP_CS_2_NRD_MLR_MASK;
2665 		break;
2666 	default:
2667 		return -EINVAL;
2668 	}
2669 
2670 	val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
2671 
2672 	switch (lanes) {
2673 	case 1:
2674 		break;
2675 	case 2:
2676 		val |= DP_COMMON_CAP_2_LANES;
2677 		break;
2678 	case 4:
2679 		val |= DP_COMMON_CAP_4_LANES;
2680 		break;
2681 	default:
2682 		return -EINVAL;
2683 	}
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_granularity() - Return granularity for the bandwidth values
2691  * @port: DP IN adapter
2692  *
2693  * Reads the programmed granularity from @port. If the DP IN adapter does
2694  * not support bandwidth allocation mode returns %-EOPNOTSUPP and negative
2695  * errno in other error cases.
2696  */
2697 int usb4_dp_port_granularity(struct tb_port *port)
2698 {
2699 	u32 val;
2700 	int ret;
2701 
2702 	if (!is_usb4_dpin(port))
2703 		return -EOPNOTSUPP;
2704 
2705 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2706 			   port->cap_adap + ADP_DP_CS_2, 1);
2707 	if (ret)
2708 		return ret;
2709 
2710 	val &= ADP_DP_CS_2_GR_MASK;
2711 	val >>= ADP_DP_CS_2_GR_SHIFT;
2712 
2713 	switch (val) {
2714 	case ADP_DP_CS_2_GR_0_25G:
2715 		return 250;
2716 	case ADP_DP_CS_2_GR_0_5G:
2717 		return 500;
2718 	case ADP_DP_CS_2_GR_1G:
2719 		return 1000;
2720 	}
2721 
2722 	return -EINVAL;
2723 }
2724 
2725 /**
2726  * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
2727  * @port: DP IN adapter
2728  * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
2729  *
2730  * Sets the granularity used with the estimated, allocated and requested
2731  * bandwidth. Returns %0 in success and negative errno otherwise. If the
2732  * adapter does not support this %-EOPNOTSUPP is returned.
2733  */
2734 int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
2735 {
2736 	u32 val;
2737 	int ret;
2738 
2739 	if (!is_usb4_dpin(port))
2740 		return -EOPNOTSUPP;
2741 
2742 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2743 			   port->cap_adap + ADP_DP_CS_2, 1);
2744 	if (ret)
2745 		return ret;
2746 
2747 	val &= ~ADP_DP_CS_2_GR_MASK;
2748 
2749 	switch (granularity) {
2750 	case 250:
2751 		val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
2752 		break;
2753 	case 500:
2754 		val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
2755 		break;
2756 	case 1000:
2757 		val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
2758 		break;
2759 	default:
2760 		return -EINVAL;
2761 	}
2762 
2763 	return tb_port_write(port, &val, TB_CFG_PORT,
2764 			     port->cap_adap + ADP_DP_CS_2, 1);
2765 }
2766 
2767 /**
2768  * usb4_dp_port_set_estimated_bandwidth() - Set estimated bandwidth
2769  * @port: DP IN adapter
2770  * @bw: Estimated bandwidth in Mb/s.
2771  *
2772  * Sets the estimated bandwidth to @bw. Set the granularity by calling
2773  * usb4_dp_port_set_granularity() before calling this. The @bw is round
2774  * down to the closest granularity multiplier. Returns %0 in success
2775  * and negative errno otherwise. Specifically returns %-EOPNOTSUPP if
2776  * the adapter does not support this.
2777  */
2778 int usb4_dp_port_set_estimated_bandwidth(struct tb_port *port, int bw)
2779 {
2780 	u32 val, granularity;
2781 	int ret;
2782 
2783 	if (!is_usb4_dpin(port))
2784 		return -EOPNOTSUPP;
2785 
2786 	ret = usb4_dp_port_granularity(port);
2787 	if (ret < 0)
2788 		return ret;
2789 	granularity = ret;
2790 
2791 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2792 			   port->cap_adap + ADP_DP_CS_2, 1);
2793 	if (ret)
2794 		return ret;
2795 
2796 	val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
2797 	val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
2798 
2799 	return tb_port_write(port, &val, TB_CFG_PORT,
2800 			     port->cap_adap + ADP_DP_CS_2, 1);
2801 }
2802 
2803 /**
2804  * usb4_dp_port_allocated_bandwidth() - Return allocated bandwidth
2805  * @port: DP IN adapter
2806  *
2807  * Reads and returns allocated bandwidth for @port in Mb/s (taking into
2808  * account the programmed granularity). Returns negative errno in case
2809  * of error.
2810  */
2811 int usb4_dp_port_allocated_bandwidth(struct tb_port *port)
2812 {
2813 	u32 val, granularity;
2814 	int ret;
2815 
2816 	if (!is_usb4_dpin(port))
2817 		return -EOPNOTSUPP;
2818 
2819 	ret = usb4_dp_port_granularity(port);
2820 	if (ret < 0)
2821 		return ret;
2822 	granularity = ret;
2823 
2824 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2825 			   port->cap_adap + DP_STATUS, 1);
2826 	if (ret)
2827 		return ret;
2828 
2829 	val &= DP_STATUS_ALLOCATED_BW_MASK;
2830 	val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
2831 
2832 	return val * granularity;
2833 }
2834 
2835 static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
2836 {
2837 	u32 val;
2838 	int ret;
2839 
2840 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2841 			   port->cap_adap + ADP_DP_CS_2, 1);
2842 	if (ret)
2843 		return ret;
2844 
2845 	if (ack)
2846 		val |= ADP_DP_CS_2_CA;
2847 	else
2848 		val &= ~ADP_DP_CS_2_CA;
2849 
2850 	return tb_port_write(port, &val, TB_CFG_PORT,
2851 			     port->cap_adap + ADP_DP_CS_2, 1);
2852 }
2853 
2854 static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
2855 {
2856 	return __usb4_dp_port_set_cm_ack(port, true);
2857 }
2858 
2859 static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
2860 					      int timeout_msec)
2861 {
2862 	ktime_t end;
2863 	u32 val;
2864 	int ret;
2865 
2866 	ret = __usb4_dp_port_set_cm_ack(port, false);
2867 	if (ret)
2868 		return ret;
2869 
2870 	end = ktime_add_ms(ktime_get(), timeout_msec);
2871 	do {
2872 		ret = tb_port_read(port, &val, TB_CFG_PORT,
2873 				   port->cap_adap + ADP_DP_CS_8, 1);
2874 		if (ret)
2875 			return ret;
2876 
2877 		if (!(val & ADP_DP_CS_8_DR))
2878 			break;
2879 
2880 		usleep_range(50, 100);
2881 	} while (ktime_before(ktime_get(), end));
2882 
2883 	if (val & ADP_DP_CS_8_DR) {
2884 		tb_port_warn(port, "timeout waiting for DPTX request to clear\n");
2885 		return -ETIMEDOUT;
2886 	}
2887 
2888 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2889 			   port->cap_adap + ADP_DP_CS_2, 1);
2890 	if (ret)
2891 		return ret;
2892 
2893 	val &= ~ADP_DP_CS_2_CA;
2894 	return tb_port_write(port, &val, TB_CFG_PORT,
2895 			     port->cap_adap + ADP_DP_CS_2, 1);
2896 }
2897 
2898 /**
2899  * usb4_dp_port_allocate_bandwidth() - Set allocated bandwidth
2900  * @port: DP IN adapter
2901  * @bw: New allocated bandwidth in Mb/s
2902  *
2903  * Communicates the new allocated bandwidth with the DPCD (graphics
2904  * driver). Takes into account the programmed granularity. Returns %0 in
2905  * success and negative errno in case of error.
2906  */
2907 int usb4_dp_port_allocate_bandwidth(struct tb_port *port, int bw)
2908 {
2909 	u32 val, granularity;
2910 	int ret;
2911 
2912 	if (!is_usb4_dpin(port))
2913 		return -EOPNOTSUPP;
2914 
2915 	ret = usb4_dp_port_granularity(port);
2916 	if (ret < 0)
2917 		return ret;
2918 	granularity = ret;
2919 
2920 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2921 			   port->cap_adap + DP_STATUS, 1);
2922 	if (ret)
2923 		return ret;
2924 
2925 	val &= ~DP_STATUS_ALLOCATED_BW_MASK;
2926 	val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
2927 
2928 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2929 			    port->cap_adap + DP_STATUS, 1);
2930 	if (ret)
2931 		return ret;
2932 
2933 	ret = usb4_dp_port_set_cm_ack(port);
2934 	if (ret)
2935 		return ret;
2936 
2937 	return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
2938 }
2939 
2940 /**
2941  * usb4_dp_port_requested_bandwidth() - Read requested bandwidth
2942  * @port: DP IN adapter
2943  *
2944  * Reads the DPCD (graphics driver) requested bandwidth and returns it
2945  * in Mb/s. Takes the programmed granularity into account. In case of
2946  * error returns negative errno. Specifically returns %-EOPNOTSUPP if
2947  * the adapter does not support bandwidth allocation mode, and %ENODATA
2948  * if there is no active bandwidth request from the graphics driver.
2949  */
2950 int usb4_dp_port_requested_bandwidth(struct tb_port *port)
2951 {
2952 	u32 val, granularity;
2953 	int ret;
2954 
2955 	if (!is_usb4_dpin(port))
2956 		return -EOPNOTSUPP;
2957 
2958 	ret = usb4_dp_port_granularity(port);
2959 	if (ret < 0)
2960 		return ret;
2961 	granularity = ret;
2962 
2963 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2964 			   port->cap_adap + ADP_DP_CS_8, 1);
2965 	if (ret)
2966 		return ret;
2967 
2968 	if (!(val & ADP_DP_CS_8_DR))
2969 		return -ENODATA;
2970 
2971 	return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
2972 }
2973 
2974 /**
2975  * usb4_pci_port_set_ext_encapsulation() - Enable/disable extended encapsulation
2976  * @port: PCIe adapter
2977  * @enable: Enable/disable extended encapsulation
2978  *
2979  * Enables or disables extended encapsulation used in PCIe tunneling. Caller
2980  * needs to make sure both adapters support this before enabling. Returns %0 on
2981  * success and negative errno otherwise.
2982  */
2983 int usb4_pci_port_set_ext_encapsulation(struct tb_port *port, bool enable)
2984 {
2985 	u32 val;
2986 	int ret;
2987 
2988 	if (!tb_port_is_pcie_up(port) && !tb_port_is_pcie_down(port))
2989 		return -EINVAL;
2990 
2991 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2992 			   port->cap_adap + ADP_PCIE_CS_1, 1);
2993 	if (ret)
2994 		return ret;
2995 
2996 	if (enable)
2997 		val |= ADP_PCIE_CS_1_EE;
2998 	else
2999 		val &= ~ADP_PCIE_CS_1_EE;
3000 
3001 	return tb_port_write(port, &val, TB_CFG_PORT,
3002 			     port->cap_adap + ADP_PCIE_CS_1, 1);
3003 }
3004