xref: /linux/drivers/thunderbolt/usb4.c (revision 2eff01ee2881becc9daaa0d53477ec202136b1f4)
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		1000
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  * @ncaps: Number of elements in the caps array
1635  *
1636  * Reads the USB4 port lane margining capabilities into @caps.
1637  */
1638 int usb4_port_margining_caps(struct tb_port *port, enum usb4_sb_target target,
1639 			     u8 index, u32 *caps, size_t ncaps)
1640 {
1641 	int ret;
1642 
1643 	ret = usb4_port_sb_op(port, target, index,
1644 			      USB4_SB_OPCODE_READ_LANE_MARGINING_CAP, 500);
1645 	if (ret)
1646 		return ret;
1647 
1648 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, caps,
1649 				 sizeof(*caps) * ncaps);
1650 }
1651 
1652 /**
1653  * usb4_port_hw_margin() - Run hardware lane margining on port
1654  * @port: USB4 port
1655  * @target: Sideband target
1656  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1657  * @params: Parameters for USB4 hardware margining
1658  * @results: Array to hold the results
1659  * @nresults: Number of elements in the results array
1660  *
1661  * Runs hardware lane margining on USB4 port and returns the result in
1662  * @results.
1663  */
1664 int usb4_port_hw_margin(struct tb_port *port, enum usb4_sb_target target,
1665 			u8 index, const struct usb4_port_margining_params *params,
1666 			u32 *results, size_t nresults)
1667 {
1668 	u32 val;
1669 	int ret;
1670 
1671 	if (WARN_ON_ONCE(!params))
1672 		return -EINVAL;
1673 
1674 	val = params->lanes;
1675 	if (params->time)
1676 		val |= USB4_MARGIN_HW_TIME;
1677 	if (params->right_high || params->upper_eye)
1678 		val |= USB4_MARGIN_HW_RHU;
1679 	if (params->ber_level)
1680 		val |= FIELD_PREP(USB4_MARGIN_HW_BER_MASK, params->ber_level);
1681 	if (params->optional_voltage_offset_range)
1682 		val |= USB4_MARGIN_HW_OPT_VOLTAGE;
1683 
1684 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1685 				 sizeof(val));
1686 	if (ret)
1687 		return ret;
1688 
1689 	ret = usb4_port_sb_op(port, target, index,
1690 			      USB4_SB_OPCODE_RUN_HW_LANE_MARGINING, 2500);
1691 	if (ret)
1692 		return ret;
1693 
1694 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, results,
1695 				 sizeof(*results) * nresults);
1696 }
1697 
1698 /**
1699  * usb4_port_sw_margin() - Run software lane margining on port
1700  * @port: USB4 port
1701  * @target: Sideband target
1702  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1703  * @params: Parameters for USB4 software margining
1704  * @results: Data word for the operation completion data
1705  *
1706  * Runs software lane margining on USB4 port. Read back the error
1707  * counters by calling usb4_port_sw_margin_errors(). Returns %0 in
1708  * success and negative errno otherwise.
1709  */
1710 int usb4_port_sw_margin(struct tb_port *port, enum usb4_sb_target target,
1711 			u8 index, const struct usb4_port_margining_params *params,
1712 			u32 *results)
1713 {
1714 	u32 val;
1715 	int ret;
1716 
1717 	if (WARN_ON_ONCE(!params))
1718 		return -EINVAL;
1719 
1720 	val = params->lanes;
1721 	if (params->time)
1722 		val |= USB4_MARGIN_SW_TIME;
1723 	if (params->optional_voltage_offset_range)
1724 		val |= USB4_MARGIN_SW_OPT_VOLTAGE;
1725 	if (params->right_high)
1726 		val |= USB4_MARGIN_SW_RH;
1727 	if (params->upper_eye)
1728 		val |= USB4_MARGIN_SW_UPPER_EYE;
1729 	val |= FIELD_PREP(USB4_MARGIN_SW_COUNTER_MASK, params->error_counter);
1730 	val |= FIELD_PREP(USB4_MARGIN_SW_VT_MASK, params->voltage_time_offset);
1731 
1732 	ret = usb4_port_sb_write(port, target, index, USB4_SB_METADATA, &val,
1733 				 sizeof(val));
1734 	if (ret)
1735 		return ret;
1736 
1737 	ret = usb4_port_sb_op(port, target, index,
1738 			      USB4_SB_OPCODE_RUN_SW_LANE_MARGINING, 2500);
1739 	if (ret)
1740 		return ret;
1741 
1742 	return usb4_port_sb_read(port, target, index, USB4_SB_DATA, results,
1743 				 sizeof(*results));
1744 
1745 }
1746 
1747 /**
1748  * usb4_port_sw_margin_errors() - Read the software margining error counters
1749  * @port: USB4 port
1750  * @target: Sideband target
1751  * @index: Retimer index if taget is %USB4_SB_TARGET_RETIMER
1752  * @errors: Error metadata is copied here.
1753  *
1754  * This reads back the software margining error counters from the port.
1755  * Returns %0 in success and negative errno otherwise.
1756  */
1757 int usb4_port_sw_margin_errors(struct tb_port *port, enum usb4_sb_target target,
1758 			       u8 index, u32 *errors)
1759 {
1760 	int ret;
1761 
1762 	ret = usb4_port_sb_op(port, target, index,
1763 			      USB4_SB_OPCODE_READ_SW_MARGIN_ERR, 150);
1764 	if (ret)
1765 		return ret;
1766 
1767 	return usb4_port_sb_read(port, target, index, USB4_SB_METADATA, errors,
1768 				 sizeof(*errors));
1769 }
1770 
1771 static inline int usb4_port_retimer_op(struct tb_port *port, u8 index,
1772 				       enum usb4_sb_opcode opcode,
1773 				       int timeout_msec)
1774 {
1775 	return usb4_port_sb_op(port, USB4_SB_TARGET_RETIMER, index, opcode,
1776 			       timeout_msec);
1777 }
1778 
1779 /**
1780  * usb4_port_retimer_set_inbound_sbtx() - Enable sideband channel transactions
1781  * @port: USB4 port
1782  * @index: Retimer index
1783  *
1784  * Enables sideband channel transations on SBTX. Can be used when USB4
1785  * link does not go up, for example if there is no device connected.
1786  */
1787 int usb4_port_retimer_set_inbound_sbtx(struct tb_port *port, u8 index)
1788 {
1789 	int ret;
1790 
1791 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1792 				   500);
1793 
1794 	if (ret != -ENODEV)
1795 		return ret;
1796 
1797 	/*
1798 	 * Per the USB4 retimer spec, the retimer is not required to
1799 	 * send an RT (Retimer Transaction) response for the first
1800 	 * SET_INBOUND_SBTX command
1801 	 */
1802 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_SET_INBOUND_SBTX,
1803 				    500);
1804 }
1805 
1806 /**
1807  * usb4_port_retimer_unset_inbound_sbtx() - Disable sideband channel transactions
1808  * @port: USB4 port
1809  * @index: Retimer index
1810  *
1811  * Disables sideband channel transations on SBTX. The reverse of
1812  * usb4_port_retimer_set_inbound_sbtx().
1813  */
1814 int usb4_port_retimer_unset_inbound_sbtx(struct tb_port *port, u8 index)
1815 {
1816 	return usb4_port_retimer_op(port, index,
1817 				    USB4_SB_OPCODE_UNSET_INBOUND_SBTX, 500);
1818 }
1819 
1820 /**
1821  * usb4_port_retimer_is_last() - Is the retimer last on-board retimer
1822  * @port: USB4 port
1823  * @index: Retimer index
1824  *
1825  * If the retimer at @index is last one (connected directly to the
1826  * Type-C port) this function returns %1. If it is not returns %0. If
1827  * the retimer is not present returns %-ENODEV. Otherwise returns
1828  * negative errno.
1829  */
1830 int usb4_port_retimer_is_last(struct tb_port *port, u8 index)
1831 {
1832 	u32 metadata;
1833 	int ret;
1834 
1835 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_LAST_RETIMER,
1836 				   500);
1837 	if (ret)
1838 		return ret;
1839 
1840 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1841 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1842 	return ret ? ret : metadata & 1;
1843 }
1844 
1845 /**
1846  * usb4_port_retimer_is_cable() - Is the retimer cable retimer
1847  * @port: USB4 port
1848  * @index: Retimer index
1849  *
1850  * If the retimer at @index is last cable retimer this function returns
1851  * %1 and %0 if it is on-board retimer. In case a retimer is not present
1852  * at @index returns %-ENODEV. Otherwise returns negative errno.
1853  */
1854 int usb4_port_retimer_is_cable(struct tb_port *port, u8 index)
1855 {
1856 	u32 metadata;
1857 	int ret;
1858 
1859 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_QUERY_CABLE_RETIMER,
1860 				   500);
1861 	if (ret)
1862 		return ret;
1863 
1864 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1865 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1866 	return ret ? ret : metadata & 1;
1867 }
1868 
1869 /**
1870  * usb4_port_retimer_nvm_sector_size() - Read retimer NVM sector size
1871  * @port: USB4 port
1872  * @index: Retimer index
1873  *
1874  * Reads NVM sector size (in bytes) of a retimer at @index. This
1875  * operation can be used to determine whether the retimer supports NVM
1876  * upgrade for example. Returns sector size in bytes or negative errno
1877  * in case of error. Specifically returns %-ENODEV if there is no
1878  * retimer at @index.
1879  */
1880 int usb4_port_retimer_nvm_sector_size(struct tb_port *port, u8 index)
1881 {
1882 	u32 metadata;
1883 	int ret;
1884 
1885 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_GET_NVM_SECTOR_SIZE,
1886 				   500);
1887 	if (ret)
1888 		return ret;
1889 
1890 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
1891 				USB4_SB_METADATA, &metadata, sizeof(metadata));
1892 	return ret ? ret : metadata & USB4_NVM_SECTOR_SIZE_MASK;
1893 }
1894 
1895 /**
1896  * usb4_port_retimer_nvm_set_offset() - Set NVM write offset
1897  * @port: USB4 port
1898  * @index: Retimer index
1899  * @address: Start offset
1900  *
1901  * Exlicitly sets NVM write offset. Normally when writing to NVM this is
1902  * done automatically by usb4_port_retimer_nvm_write().
1903  *
1904  * Returns %0 in success and negative errno if there was a failure.
1905  */
1906 int usb4_port_retimer_nvm_set_offset(struct tb_port *port, u8 index,
1907 				     unsigned int address)
1908 {
1909 	u32 metadata, dwaddress;
1910 	int ret;
1911 
1912 	dwaddress = address / 4;
1913 	metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
1914 		  USB4_NVM_SET_OFFSET_MASK;
1915 
1916 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1917 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
1918 	if (ret)
1919 		return ret;
1920 
1921 	return usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_SET_OFFSET,
1922 				    500);
1923 }
1924 
1925 struct retimer_info {
1926 	struct tb_port *port;
1927 	u8 index;
1928 };
1929 
1930 static int usb4_port_retimer_nvm_write_next_block(void *data,
1931 	unsigned int dwaddress, const void *buf, size_t dwords)
1932 
1933 {
1934 	const struct retimer_info *info = data;
1935 	struct tb_port *port = info->port;
1936 	u8 index = info->index;
1937 	int ret;
1938 
1939 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1940 				 USB4_SB_DATA, buf, dwords * 4);
1941 	if (ret)
1942 		return ret;
1943 
1944 	return usb4_port_retimer_op(port, index,
1945 			USB4_SB_OPCODE_NVM_BLOCK_WRITE, 1000);
1946 }
1947 
1948 /**
1949  * usb4_port_retimer_nvm_write() - Write to retimer NVM
1950  * @port: USB4 port
1951  * @index: Retimer index
1952  * @address: Byte address where to start the write
1953  * @buf: Data to write
1954  * @size: Size in bytes how much to write
1955  *
1956  * Writes @size bytes from @buf to the retimer NVM. Used for NVM
1957  * upgrade. Returns %0 if the data was written successfully and negative
1958  * errno in case of failure. Specifically returns %-ENODEV if there is
1959  * no retimer at @index.
1960  */
1961 int usb4_port_retimer_nvm_write(struct tb_port *port, u8 index, unsigned int address,
1962 				const void *buf, size_t size)
1963 {
1964 	struct retimer_info info = { .port = port, .index = index };
1965 	int ret;
1966 
1967 	ret = usb4_port_retimer_nvm_set_offset(port, index, address);
1968 	if (ret)
1969 		return ret;
1970 
1971 	return tb_nvm_write_data(address, buf, size, USB4_DATA_RETRIES,
1972 				 usb4_port_retimer_nvm_write_next_block, &info);
1973 }
1974 
1975 /**
1976  * usb4_port_retimer_nvm_authenticate() - Start retimer NVM upgrade
1977  * @port: USB4 port
1978  * @index: Retimer index
1979  *
1980  * After the new NVM image has been written via usb4_port_retimer_nvm_write()
1981  * this function can be used to trigger the NVM upgrade process. If
1982  * successful the retimer restarts with the new NVM and may not have the
1983  * index set so one needs to call usb4_port_enumerate_retimers() to
1984  * force index to be assigned.
1985  */
1986 int usb4_port_retimer_nvm_authenticate(struct tb_port *port, u8 index)
1987 {
1988 	u32 val;
1989 
1990 	/*
1991 	 * We need to use the raw operation here because once the
1992 	 * authentication completes the retimer index is not set anymore
1993 	 * so we do not get back the status now.
1994 	 */
1995 	val = USB4_SB_OPCODE_NVM_AUTH_WRITE;
1996 	return usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
1997 				  USB4_SB_OPCODE, &val, sizeof(val));
1998 }
1999 
2000 /**
2001  * usb4_port_retimer_nvm_authenticate_status() - Read status of NVM upgrade
2002  * @port: USB4 port
2003  * @index: Retimer index
2004  * @status: Raw status code read from metadata
2005  *
2006  * This can be called after usb4_port_retimer_nvm_authenticate() and
2007  * usb4_port_enumerate_retimers() to fetch status of the NVM upgrade.
2008  *
2009  * Returns %0 if the authentication status was successfully read. The
2010  * completion metadata (the result) is then stored into @status. If
2011  * reading the status fails, returns negative errno.
2012  */
2013 int usb4_port_retimer_nvm_authenticate_status(struct tb_port *port, u8 index,
2014 					      u32 *status)
2015 {
2016 	u32 metadata, val;
2017 	int ret;
2018 
2019 	ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2020 				USB4_SB_OPCODE, &val, sizeof(val));
2021 	if (ret)
2022 		return ret;
2023 
2024 	ret = usb4_port_sb_opcode_err_to_errno(val);
2025 	switch (ret) {
2026 	case 0:
2027 		*status = 0;
2028 		return 0;
2029 
2030 	case -EAGAIN:
2031 		ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2032 					USB4_SB_METADATA, &metadata,
2033 					sizeof(metadata));
2034 		if (ret)
2035 			return ret;
2036 
2037 		*status = metadata & USB4_SB_METADATA_NVM_AUTH_WRITE_MASK;
2038 		return 0;
2039 
2040 	default:
2041 		return ret;
2042 	}
2043 }
2044 
2045 static int usb4_port_retimer_nvm_read_block(void *data, unsigned int dwaddress,
2046 					    void *buf, size_t dwords)
2047 {
2048 	const struct retimer_info *info = data;
2049 	struct tb_port *port = info->port;
2050 	u8 index = info->index;
2051 	u32 metadata;
2052 	int ret;
2053 
2054 	metadata = dwaddress << USB4_NVM_READ_OFFSET_SHIFT;
2055 	if (dwords < USB4_DATA_DWORDS)
2056 		metadata |= dwords << USB4_NVM_READ_LENGTH_SHIFT;
2057 
2058 	ret = usb4_port_sb_write(port, USB4_SB_TARGET_RETIMER, index,
2059 				 USB4_SB_METADATA, &metadata, sizeof(metadata));
2060 	if (ret)
2061 		return ret;
2062 
2063 	ret = usb4_port_retimer_op(port, index, USB4_SB_OPCODE_NVM_READ, 500);
2064 	if (ret)
2065 		return ret;
2066 
2067 	return usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
2068 				 USB4_SB_DATA, buf, dwords * 4);
2069 }
2070 
2071 /**
2072  * usb4_port_retimer_nvm_read() - Read contents of retimer NVM
2073  * @port: USB4 port
2074  * @index: Retimer index
2075  * @address: NVM address (in bytes) to start reading
2076  * @buf: Data read from NVM is stored here
2077  * @size: Number of bytes to read
2078  *
2079  * Reads retimer NVM and copies the contents to @buf. Returns %0 if the
2080  * read was successful and negative errno in case of failure.
2081  * Specifically returns %-ENODEV if there is no retimer at @index.
2082  */
2083 int usb4_port_retimer_nvm_read(struct tb_port *port, u8 index,
2084 			       unsigned int address, void *buf, size_t size)
2085 {
2086 	struct retimer_info info = { .port = port, .index = index };
2087 
2088 	return tb_nvm_read_data(address, buf, size, USB4_DATA_RETRIES,
2089 				usb4_port_retimer_nvm_read_block, &info);
2090 }
2091 
2092 static inline unsigned int
2093 usb4_usb3_port_max_bandwidth(const struct tb_port *port, unsigned int bw)
2094 {
2095 	/* Take the possible bandwidth limitation into account */
2096 	if (port->max_bw)
2097 		return min(bw, port->max_bw);
2098 	return bw;
2099 }
2100 
2101 /**
2102  * usb4_usb3_port_max_link_rate() - Maximum support USB3 link rate
2103  * @port: USB3 adapter port
2104  *
2105  * Return maximum supported link rate of a USB3 adapter in Mb/s.
2106  * Negative errno in case of error.
2107  */
2108 int usb4_usb3_port_max_link_rate(struct tb_port *port)
2109 {
2110 	int ret, lr;
2111 	u32 val;
2112 
2113 	if (!tb_port_is_usb3_down(port) && !tb_port_is_usb3_up(port))
2114 		return -EINVAL;
2115 
2116 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2117 			   port->cap_adap + ADP_USB3_CS_4, 1);
2118 	if (ret)
2119 		return ret;
2120 
2121 	lr = (val & ADP_USB3_CS_4_MSLR_MASK) >> ADP_USB3_CS_4_MSLR_SHIFT;
2122 	ret = lr == ADP_USB3_CS_4_MSLR_20G ? 20000 : 10000;
2123 
2124 	return usb4_usb3_port_max_bandwidth(port, ret);
2125 }
2126 
2127 static int usb4_usb3_port_cm_request(struct tb_port *port, bool request)
2128 {
2129 	int ret;
2130 	u32 val;
2131 
2132 	if (!tb_port_is_usb3_down(port))
2133 		return -EINVAL;
2134 	if (tb_route(port->sw))
2135 		return -EINVAL;
2136 
2137 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2138 			   port->cap_adap + ADP_USB3_CS_2, 1);
2139 	if (ret)
2140 		return ret;
2141 
2142 	if (request)
2143 		val |= ADP_USB3_CS_2_CMR;
2144 	else
2145 		val &= ~ADP_USB3_CS_2_CMR;
2146 
2147 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2148 			    port->cap_adap + ADP_USB3_CS_2, 1);
2149 	if (ret)
2150 		return ret;
2151 
2152 	/*
2153 	 * We can use val here directly as the CMR bit is in the same place
2154 	 * as HCA. Just mask out others.
2155 	 */
2156 	val &= ADP_USB3_CS_2_CMR;
2157 	return usb4_port_wait_for_bit(port, port->cap_adap + ADP_USB3_CS_1,
2158 				      ADP_USB3_CS_1_HCA, val, 1500,
2159 				      USB4_PORT_DELAY);
2160 }
2161 
2162 static inline int usb4_usb3_port_set_cm_request(struct tb_port *port)
2163 {
2164 	return usb4_usb3_port_cm_request(port, true);
2165 }
2166 
2167 static inline int usb4_usb3_port_clear_cm_request(struct tb_port *port)
2168 {
2169 	return usb4_usb3_port_cm_request(port, false);
2170 }
2171 
2172 static unsigned int usb3_bw_to_mbps(u32 bw, u8 scale)
2173 {
2174 	unsigned long uframes;
2175 
2176 	uframes = bw * 512UL << scale;
2177 	return DIV_ROUND_CLOSEST(uframes * 8000, MEGA);
2178 }
2179 
2180 static u32 mbps_to_usb3_bw(unsigned int mbps, u8 scale)
2181 {
2182 	unsigned long uframes;
2183 
2184 	/* 1 uframe is 1/8 ms (125 us) -> 1 / 8000 s */
2185 	uframes = ((unsigned long)mbps * MEGA) / 8000;
2186 	return DIV_ROUND_UP(uframes, 512UL << scale);
2187 }
2188 
2189 static int usb4_usb3_port_read_allocated_bandwidth(struct tb_port *port,
2190 						   int *upstream_bw,
2191 						   int *downstream_bw)
2192 {
2193 	u32 val, bw, scale;
2194 	int ret;
2195 
2196 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2197 			   port->cap_adap + ADP_USB3_CS_2, 1);
2198 	if (ret)
2199 		return ret;
2200 
2201 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2202 			   port->cap_adap + ADP_USB3_CS_3, 1);
2203 	if (ret)
2204 		return ret;
2205 
2206 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2207 
2208 	bw = val & ADP_USB3_CS_2_AUBW_MASK;
2209 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2210 
2211 	bw = (val & ADP_USB3_CS_2_ADBW_MASK) >> ADP_USB3_CS_2_ADBW_SHIFT;
2212 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2213 
2214 	return 0;
2215 }
2216 
2217 /**
2218  * usb4_usb3_port_allocated_bandwidth() - Bandwidth allocated for USB3
2219  * @port: USB3 adapter port
2220  * @upstream_bw: Allocated upstream bandwidth is stored here
2221  * @downstream_bw: Allocated downstream bandwidth is stored here
2222  *
2223  * Stores currently allocated USB3 bandwidth into @upstream_bw and
2224  * @downstream_bw in Mb/s. Returns %0 in case of success and negative
2225  * errno in failure.
2226  */
2227 int usb4_usb3_port_allocated_bandwidth(struct tb_port *port, int *upstream_bw,
2228 				       int *downstream_bw)
2229 {
2230 	int ret;
2231 
2232 	ret = usb4_usb3_port_set_cm_request(port);
2233 	if (ret)
2234 		return ret;
2235 
2236 	ret = usb4_usb3_port_read_allocated_bandwidth(port, upstream_bw,
2237 						      downstream_bw);
2238 	usb4_usb3_port_clear_cm_request(port);
2239 
2240 	return ret;
2241 }
2242 
2243 static int usb4_usb3_port_read_consumed_bandwidth(struct tb_port *port,
2244 						  int *upstream_bw,
2245 						  int *downstream_bw)
2246 {
2247 	u32 val, bw, scale;
2248 	int ret;
2249 
2250 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2251 			   port->cap_adap + ADP_USB3_CS_1, 1);
2252 	if (ret)
2253 		return ret;
2254 
2255 	ret = tb_port_read(port, &scale, TB_CFG_PORT,
2256 			   port->cap_adap + ADP_USB3_CS_3, 1);
2257 	if (ret)
2258 		return ret;
2259 
2260 	scale &= ADP_USB3_CS_3_SCALE_MASK;
2261 
2262 	bw = val & ADP_USB3_CS_1_CUBW_MASK;
2263 	*upstream_bw = usb3_bw_to_mbps(bw, scale);
2264 
2265 	bw = (val & ADP_USB3_CS_1_CDBW_MASK) >> ADP_USB3_CS_1_CDBW_SHIFT;
2266 	*downstream_bw = usb3_bw_to_mbps(bw, scale);
2267 
2268 	return 0;
2269 }
2270 
2271 static int usb4_usb3_port_write_allocated_bandwidth(struct tb_port *port,
2272 						    int upstream_bw,
2273 						    int downstream_bw)
2274 {
2275 	u32 val, ubw, dbw, scale;
2276 	int ret, max_bw;
2277 
2278 	/* Figure out suitable scale */
2279 	scale = 0;
2280 	max_bw = max(upstream_bw, downstream_bw);
2281 	while (scale < 64) {
2282 		if (mbps_to_usb3_bw(max_bw, scale) < 4096)
2283 			break;
2284 		scale++;
2285 	}
2286 
2287 	if (WARN_ON(scale >= 64))
2288 		return -EINVAL;
2289 
2290 	ret = tb_port_write(port, &scale, TB_CFG_PORT,
2291 			    port->cap_adap + ADP_USB3_CS_3, 1);
2292 	if (ret)
2293 		return ret;
2294 
2295 	ubw = mbps_to_usb3_bw(upstream_bw, scale);
2296 	dbw = mbps_to_usb3_bw(downstream_bw, scale);
2297 
2298 	tb_port_dbg(port, "scaled bandwidth %u/%u, scale %u\n", ubw, dbw, scale);
2299 
2300 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2301 			   port->cap_adap + ADP_USB3_CS_2, 1);
2302 	if (ret)
2303 		return ret;
2304 
2305 	val &= ~(ADP_USB3_CS_2_AUBW_MASK | ADP_USB3_CS_2_ADBW_MASK);
2306 	val |= dbw << ADP_USB3_CS_2_ADBW_SHIFT;
2307 	val |= ubw;
2308 
2309 	return tb_port_write(port, &val, TB_CFG_PORT,
2310 			     port->cap_adap + ADP_USB3_CS_2, 1);
2311 }
2312 
2313 /**
2314  * usb4_usb3_port_allocate_bandwidth() - Allocate bandwidth for USB3
2315  * @port: USB3 adapter port
2316  * @upstream_bw: New upstream bandwidth
2317  * @downstream_bw: New downstream bandwidth
2318  *
2319  * This can be used to set how much bandwidth is allocated for the USB3
2320  * tunneled isochronous traffic. @upstream_bw and @downstream_bw are the
2321  * new values programmed to the USB3 adapter allocation registers. If
2322  * the values are lower than what is currently consumed the allocation
2323  * is set to what is currently consumed instead (consumed bandwidth
2324  * cannot be taken away by CM). The actual new values are returned in
2325  * @upstream_bw and @downstream_bw.
2326  *
2327  * Returns %0 in case of success and negative errno if there was a
2328  * failure.
2329  */
2330 int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
2331 				      int *downstream_bw)
2332 {
2333 	int ret, consumed_up, consumed_down, allocate_up, allocate_down;
2334 
2335 	ret = usb4_usb3_port_set_cm_request(port);
2336 	if (ret)
2337 		return ret;
2338 
2339 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2340 						     &consumed_down);
2341 	if (ret)
2342 		goto err_request;
2343 
2344 	/* Don't allow it go lower than what is consumed */
2345 	allocate_up = max(*upstream_bw, consumed_up);
2346 	allocate_down = max(*downstream_bw, consumed_down);
2347 
2348 	ret = usb4_usb3_port_write_allocated_bandwidth(port, allocate_up,
2349 						       allocate_down);
2350 	if (ret)
2351 		goto err_request;
2352 
2353 	*upstream_bw = allocate_up;
2354 	*downstream_bw = allocate_down;
2355 
2356 err_request:
2357 	usb4_usb3_port_clear_cm_request(port);
2358 	return ret;
2359 }
2360 
2361 /**
2362  * usb4_usb3_port_release_bandwidth() - Release allocated USB3 bandwidth
2363  * @port: USB3 adapter port
2364  * @upstream_bw: New allocated upstream bandwidth
2365  * @downstream_bw: New allocated downstream bandwidth
2366  *
2367  * Releases USB3 allocated bandwidth down to what is actually consumed.
2368  * The new bandwidth is returned in @upstream_bw and @downstream_bw.
2369  *
2370  * Returns 0% in success and negative errno in case of failure.
2371  */
2372 int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
2373 				     int *downstream_bw)
2374 {
2375 	int ret, consumed_up, consumed_down;
2376 
2377 	ret = usb4_usb3_port_set_cm_request(port);
2378 	if (ret)
2379 		return ret;
2380 
2381 	ret = usb4_usb3_port_read_consumed_bandwidth(port, &consumed_up,
2382 						     &consumed_down);
2383 	if (ret)
2384 		goto err_request;
2385 
2386 	/*
2387 	 * Always keep 900 Mb/s to make sure xHCI has at least some
2388 	 * bandwidth available for isochronous traffic.
2389 	 */
2390 	if (consumed_up < 900)
2391 		consumed_up = 900;
2392 	if (consumed_down < 900)
2393 		consumed_down = 900;
2394 
2395 	ret = usb4_usb3_port_write_allocated_bandwidth(port, consumed_up,
2396 						       consumed_down);
2397 	if (ret)
2398 		goto err_request;
2399 
2400 	*upstream_bw = consumed_up;
2401 	*downstream_bw = consumed_down;
2402 
2403 err_request:
2404 	usb4_usb3_port_clear_cm_request(port);
2405 	return ret;
2406 }
2407 
2408 static bool is_usb4_dpin(const struct tb_port *port)
2409 {
2410 	if (!tb_port_is_dpin(port))
2411 		return false;
2412 	if (!tb_switch_is_usb4(port->sw))
2413 		return false;
2414 	return true;
2415 }
2416 
2417 /**
2418  * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
2419  * @port: DP IN adapter
2420  * @cm_id: CM ID to assign
2421  *
2422  * Sets CM ID for the @port. Returns %0 on success and negative errno
2423  * otherwise. Speficially returns %-EOPNOTSUPP if the @port does not
2424  * support this.
2425  */
2426 int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
2427 {
2428 	u32 val;
2429 	int ret;
2430 
2431 	if (!is_usb4_dpin(port))
2432 		return -EOPNOTSUPP;
2433 
2434 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2435 			   port->cap_adap + ADP_DP_CS_2, 1);
2436 	if (ret)
2437 		return ret;
2438 
2439 	val &= ~ADP_DP_CS_2_CM_ID_MASK;
2440 	val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
2441 
2442 	return tb_port_write(port, &val, TB_CFG_PORT,
2443 			     port->cap_adap + ADP_DP_CS_2, 1);
2444 }
2445 
2446 /**
2447  * usb4_dp_port_bandwidth_mode_supported() - Is the bandwidth allocation mode
2448  *					     supported
2449  * @port: DP IN adapter to check
2450  *
2451  * Can be called to any DP IN adapter. Returns true if the adapter
2452  * supports USB4 bandwidth allocation mode, false otherwise.
2453  */
2454 bool usb4_dp_port_bandwidth_mode_supported(struct tb_port *port)
2455 {
2456 	int ret;
2457 	u32 val;
2458 
2459 	if (!is_usb4_dpin(port))
2460 		return false;
2461 
2462 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2463 			   port->cap_adap + DP_LOCAL_CAP, 1);
2464 	if (ret)
2465 		return false;
2466 
2467 	return !!(val & DP_COMMON_CAP_BW_MODE);
2468 }
2469 
2470 /**
2471  * usb4_dp_port_bandwidth_mode_enabled() - Is the bandwidth allocation mode
2472  *					   enabled
2473  * @port: DP IN adapter to check
2474  *
2475  * Can be called to any DP IN adapter. Returns true if the bandwidth
2476  * allocation mode has been enabled, false otherwise.
2477  */
2478 bool usb4_dp_port_bandwidth_mode_enabled(struct tb_port *port)
2479 {
2480 	int ret;
2481 	u32 val;
2482 
2483 	if (!is_usb4_dpin(port))
2484 		return false;
2485 
2486 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2487 			   port->cap_adap + ADP_DP_CS_8, 1);
2488 	if (ret)
2489 		return false;
2490 
2491 	return !!(val & ADP_DP_CS_8_DPME);
2492 }
2493 
2494 /**
2495  * usb4_dp_port_set_cm_bandwidth_mode_supported() - Set/clear CM support for
2496  *						    bandwidth allocation mode
2497  * @port: DP IN adapter
2498  * @supported: Does the CM support bandwidth allocation mode
2499  *
2500  * Can be called to any DP IN adapter. Sets or clears the CM support bit
2501  * of the DP IN adapter. Returns %0 in success and negative errno
2502  * otherwise. Specifically returns %-OPNOTSUPP if the passed in adapter
2503  * does not support this.
2504  */
2505 int usb4_dp_port_set_cm_bandwidth_mode_supported(struct tb_port *port,
2506 						 bool supported)
2507 {
2508 	u32 val;
2509 	int ret;
2510 
2511 	if (!is_usb4_dpin(port))
2512 		return -EOPNOTSUPP;
2513 
2514 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2515 			   port->cap_adap + ADP_DP_CS_2, 1);
2516 	if (ret)
2517 		return ret;
2518 
2519 	if (supported)
2520 		val |= ADP_DP_CS_2_CMMS;
2521 	else
2522 		val &= ~ADP_DP_CS_2_CMMS;
2523 
2524 	return tb_port_write(port, &val, TB_CFG_PORT,
2525 			     port->cap_adap + ADP_DP_CS_2, 1);
2526 }
2527 
2528 /**
2529  * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
2530  * @port: DP IN adapter
2531  *
2532  * Reads bandwidth allocation Group ID from the DP IN adapter and
2533  * returns it. If the adapter does not support setting Group_ID
2534  * %-EOPNOTSUPP is returned.
2535  */
2536 int usb4_dp_port_group_id(struct tb_port *port)
2537 {
2538 	u32 val;
2539 	int ret;
2540 
2541 	if (!is_usb4_dpin(port))
2542 		return -EOPNOTSUPP;
2543 
2544 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2545 			   port->cap_adap + ADP_DP_CS_2, 1);
2546 	if (ret)
2547 		return ret;
2548 
2549 	return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
2550 }
2551 
2552 /**
2553  * usb4_dp_port_set_group_id() - Set adapter Group ID
2554  * @port: DP IN adapter
2555  * @group_id: Group ID for the adapter
2556  *
2557  * Sets bandwidth allocation mode Group ID for the DP IN adapter.
2558  * Returns %0 in case of success and negative errno otherwise.
2559  * Specifically returns %-EOPNOTSUPP if the adapter does not support
2560  * this.
2561  */
2562 int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
2563 {
2564 	u32 val;
2565 	int ret;
2566 
2567 	if (!is_usb4_dpin(port))
2568 		return -EOPNOTSUPP;
2569 
2570 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2571 			   port->cap_adap + ADP_DP_CS_2, 1);
2572 	if (ret)
2573 		return ret;
2574 
2575 	val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
2576 	val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
2577 
2578 	return tb_port_write(port, &val, TB_CFG_PORT,
2579 			     port->cap_adap + ADP_DP_CS_2, 1);
2580 }
2581 
2582 /**
2583  * usb4_dp_port_nrd() - Read non-reduced rate and lanes
2584  * @port: DP IN adapter
2585  * @rate: Non-reduced rate in Mb/s is placed here
2586  * @lanes: Non-reduced lanes are placed here
2587  *
2588  * Reads the non-reduced rate and lanes from the DP IN adapter. Returns
2589  * %0 in success and negative errno otherwise. Specifically returns
2590  * %-EOPNOTSUPP if the adapter does not support this.
2591  */
2592 int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
2593 {
2594 	u32 val, tmp;
2595 	int ret;
2596 
2597 	if (!is_usb4_dpin(port))
2598 		return -EOPNOTSUPP;
2599 
2600 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2601 			   port->cap_adap + ADP_DP_CS_2, 1);
2602 	if (ret)
2603 		return ret;
2604 
2605 	tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
2606 	switch (tmp) {
2607 	case DP_COMMON_CAP_RATE_RBR:
2608 		*rate = 1620;
2609 		break;
2610 	case DP_COMMON_CAP_RATE_HBR:
2611 		*rate = 2700;
2612 		break;
2613 	case DP_COMMON_CAP_RATE_HBR2:
2614 		*rate = 5400;
2615 		break;
2616 	case DP_COMMON_CAP_RATE_HBR3:
2617 		*rate = 8100;
2618 		break;
2619 	}
2620 
2621 	tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
2622 	switch (tmp) {
2623 	case DP_COMMON_CAP_1_LANE:
2624 		*lanes = 1;
2625 		break;
2626 	case DP_COMMON_CAP_2_LANES:
2627 		*lanes = 2;
2628 		break;
2629 	case DP_COMMON_CAP_4_LANES:
2630 		*lanes = 4;
2631 		break;
2632 	}
2633 
2634 	return 0;
2635 }
2636 
2637 /**
2638  * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
2639  * @port: DP IN adapter
2640  * @rate: Non-reduced rate in Mb/s
2641  * @lanes: Non-reduced lanes
2642  *
2643  * Before the capabilities reduction this function can be used to set
2644  * the non-reduced values for the DP IN adapter. Returns %0 in success
2645  * and negative errno otherwise. If the adapter does not support this
2646  * %-EOPNOTSUPP is returned.
2647  */
2648 int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
2649 {
2650 	u32 val;
2651 	int ret;
2652 
2653 	if (!is_usb4_dpin(port))
2654 		return -EOPNOTSUPP;
2655 
2656 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2657 			   port->cap_adap + ADP_DP_CS_2, 1);
2658 	if (ret)
2659 		return ret;
2660 
2661 	val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
2662 
2663 	switch (rate) {
2664 	case 1620:
2665 		break;
2666 	case 2700:
2667 		val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
2668 			& ADP_DP_CS_2_NRD_MLR_MASK;
2669 		break;
2670 	case 5400:
2671 		val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2672 			& ADP_DP_CS_2_NRD_MLR_MASK;
2673 		break;
2674 	case 8100:
2675 		val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
2676 			& ADP_DP_CS_2_NRD_MLR_MASK;
2677 		break;
2678 	default:
2679 		return -EINVAL;
2680 	}
2681 
2682 	val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
2683 
2684 	switch (lanes) {
2685 	case 1:
2686 		break;
2687 	case 2:
2688 		val |= DP_COMMON_CAP_2_LANES;
2689 		break;
2690 	case 4:
2691 		val |= DP_COMMON_CAP_4_LANES;
2692 		break;
2693 	default:
2694 		return -EINVAL;
2695 	}
2696 
2697 	return tb_port_write(port, &val, TB_CFG_PORT,
2698 			     port->cap_adap + ADP_DP_CS_2, 1);
2699 }
2700 
2701 /**
2702  * usb4_dp_port_granularity() - Return granularity for the bandwidth values
2703  * @port: DP IN adapter
2704  *
2705  * Reads the programmed granularity from @port. If the DP IN adapter does
2706  * not support bandwidth allocation mode returns %-EOPNOTSUPP and negative
2707  * errno in other error cases.
2708  */
2709 int usb4_dp_port_granularity(struct tb_port *port)
2710 {
2711 	u32 val;
2712 	int ret;
2713 
2714 	if (!is_usb4_dpin(port))
2715 		return -EOPNOTSUPP;
2716 
2717 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2718 			   port->cap_adap + ADP_DP_CS_2, 1);
2719 	if (ret)
2720 		return ret;
2721 
2722 	val &= ADP_DP_CS_2_GR_MASK;
2723 	val >>= ADP_DP_CS_2_GR_SHIFT;
2724 
2725 	switch (val) {
2726 	case ADP_DP_CS_2_GR_0_25G:
2727 		return 250;
2728 	case ADP_DP_CS_2_GR_0_5G:
2729 		return 500;
2730 	case ADP_DP_CS_2_GR_1G:
2731 		return 1000;
2732 	}
2733 
2734 	return -EINVAL;
2735 }
2736 
2737 /**
2738  * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
2739  * @port: DP IN adapter
2740  * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
2741  *
2742  * Sets the granularity used with the estimated, allocated and requested
2743  * bandwidth. Returns %0 in success and negative errno otherwise. If the
2744  * adapter does not support this %-EOPNOTSUPP is returned.
2745  */
2746 int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
2747 {
2748 	u32 val;
2749 	int ret;
2750 
2751 	if (!is_usb4_dpin(port))
2752 		return -EOPNOTSUPP;
2753 
2754 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2755 			   port->cap_adap + ADP_DP_CS_2, 1);
2756 	if (ret)
2757 		return ret;
2758 
2759 	val &= ~ADP_DP_CS_2_GR_MASK;
2760 
2761 	switch (granularity) {
2762 	case 250:
2763 		val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
2764 		break;
2765 	case 500:
2766 		val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
2767 		break;
2768 	case 1000:
2769 		val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
2770 		break;
2771 	default:
2772 		return -EINVAL;
2773 	}
2774 
2775 	return tb_port_write(port, &val, TB_CFG_PORT,
2776 			     port->cap_adap + ADP_DP_CS_2, 1);
2777 }
2778 
2779 /**
2780  * usb4_dp_port_set_estimated_bandwidth() - Set estimated bandwidth
2781  * @port: DP IN adapter
2782  * @bw: Estimated bandwidth in Mb/s.
2783  *
2784  * Sets the estimated bandwidth to @bw. Set the granularity by calling
2785  * usb4_dp_port_set_granularity() before calling this. The @bw is round
2786  * down to the closest granularity multiplier. Returns %0 in success
2787  * and negative errno otherwise. Specifically returns %-EOPNOTSUPP if
2788  * the adapter does not support this.
2789  */
2790 int usb4_dp_port_set_estimated_bandwidth(struct tb_port *port, int bw)
2791 {
2792 	u32 val, granularity;
2793 	int ret;
2794 
2795 	if (!is_usb4_dpin(port))
2796 		return -EOPNOTSUPP;
2797 
2798 	ret = usb4_dp_port_granularity(port);
2799 	if (ret < 0)
2800 		return ret;
2801 	granularity = ret;
2802 
2803 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2804 			   port->cap_adap + ADP_DP_CS_2, 1);
2805 	if (ret)
2806 		return ret;
2807 
2808 	val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
2809 	val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
2810 
2811 	return tb_port_write(port, &val, TB_CFG_PORT,
2812 			     port->cap_adap + ADP_DP_CS_2, 1);
2813 }
2814 
2815 /**
2816  * usb4_dp_port_allocated_bandwidth() - Return allocated bandwidth
2817  * @port: DP IN adapter
2818  *
2819  * Reads and returns allocated bandwidth for @port in Mb/s (taking into
2820  * account the programmed granularity). Returns negative errno in case
2821  * of error.
2822  */
2823 int usb4_dp_port_allocated_bandwidth(struct tb_port *port)
2824 {
2825 	u32 val, granularity;
2826 	int ret;
2827 
2828 	if (!is_usb4_dpin(port))
2829 		return -EOPNOTSUPP;
2830 
2831 	ret = usb4_dp_port_granularity(port);
2832 	if (ret < 0)
2833 		return ret;
2834 	granularity = ret;
2835 
2836 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2837 			   port->cap_adap + DP_STATUS, 1);
2838 	if (ret)
2839 		return ret;
2840 
2841 	val &= DP_STATUS_ALLOCATED_BW_MASK;
2842 	val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
2843 
2844 	return val * granularity;
2845 }
2846 
2847 static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
2848 {
2849 	u32 val;
2850 	int ret;
2851 
2852 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2853 			   port->cap_adap + ADP_DP_CS_2, 1);
2854 	if (ret)
2855 		return ret;
2856 
2857 	if (ack)
2858 		val |= ADP_DP_CS_2_CA;
2859 	else
2860 		val &= ~ADP_DP_CS_2_CA;
2861 
2862 	return tb_port_write(port, &val, TB_CFG_PORT,
2863 			     port->cap_adap + ADP_DP_CS_2, 1);
2864 }
2865 
2866 static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
2867 {
2868 	return __usb4_dp_port_set_cm_ack(port, true);
2869 }
2870 
2871 static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
2872 					      int timeout_msec)
2873 {
2874 	ktime_t end;
2875 	u32 val;
2876 	int ret;
2877 
2878 	ret = __usb4_dp_port_set_cm_ack(port, false);
2879 	if (ret)
2880 		return ret;
2881 
2882 	end = ktime_add_ms(ktime_get(), timeout_msec);
2883 	do {
2884 		ret = tb_port_read(port, &val, TB_CFG_PORT,
2885 				   port->cap_adap + ADP_DP_CS_8, 1);
2886 		if (ret)
2887 			return ret;
2888 
2889 		if (!(val & ADP_DP_CS_8_DR))
2890 			break;
2891 
2892 		usleep_range(50, 100);
2893 	} while (ktime_before(ktime_get(), end));
2894 
2895 	if (val & ADP_DP_CS_8_DR) {
2896 		tb_port_warn(port, "timeout waiting for DPTX request to clear\n");
2897 		return -ETIMEDOUT;
2898 	}
2899 
2900 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2901 			   port->cap_adap + ADP_DP_CS_2, 1);
2902 	if (ret)
2903 		return ret;
2904 
2905 	val &= ~ADP_DP_CS_2_CA;
2906 	return tb_port_write(port, &val, TB_CFG_PORT,
2907 			     port->cap_adap + ADP_DP_CS_2, 1);
2908 }
2909 
2910 /**
2911  * usb4_dp_port_allocate_bandwidth() - Set allocated bandwidth
2912  * @port: DP IN adapter
2913  * @bw: New allocated bandwidth in Mb/s
2914  *
2915  * Communicates the new allocated bandwidth with the DPCD (graphics
2916  * driver). Takes into account the programmed granularity. Returns %0 in
2917  * success and negative errno in case of error.
2918  */
2919 int usb4_dp_port_allocate_bandwidth(struct tb_port *port, int bw)
2920 {
2921 	u32 val, granularity;
2922 	int ret;
2923 
2924 	if (!is_usb4_dpin(port))
2925 		return -EOPNOTSUPP;
2926 
2927 	ret = usb4_dp_port_granularity(port);
2928 	if (ret < 0)
2929 		return ret;
2930 	granularity = ret;
2931 
2932 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2933 			   port->cap_adap + DP_STATUS, 1);
2934 	if (ret)
2935 		return ret;
2936 
2937 	val &= ~DP_STATUS_ALLOCATED_BW_MASK;
2938 	val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
2939 
2940 	ret = tb_port_write(port, &val, TB_CFG_PORT,
2941 			    port->cap_adap + DP_STATUS, 1);
2942 	if (ret)
2943 		return ret;
2944 
2945 	ret = usb4_dp_port_set_cm_ack(port);
2946 	if (ret)
2947 		return ret;
2948 
2949 	return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
2950 }
2951 
2952 /**
2953  * usb4_dp_port_requested_bandwidth() - Read requested bandwidth
2954  * @port: DP IN adapter
2955  *
2956  * Reads the DPCD (graphics driver) requested bandwidth and returns it
2957  * in Mb/s. Takes the programmed granularity into account. In case of
2958  * error returns negative errno. Specifically returns %-EOPNOTSUPP if
2959  * the adapter does not support bandwidth allocation mode, and %ENODATA
2960  * if there is no active bandwidth request from the graphics driver.
2961  */
2962 int usb4_dp_port_requested_bandwidth(struct tb_port *port)
2963 {
2964 	u32 val, granularity;
2965 	int ret;
2966 
2967 	if (!is_usb4_dpin(port))
2968 		return -EOPNOTSUPP;
2969 
2970 	ret = usb4_dp_port_granularity(port);
2971 	if (ret < 0)
2972 		return ret;
2973 	granularity = ret;
2974 
2975 	ret = tb_port_read(port, &val, TB_CFG_PORT,
2976 			   port->cap_adap + ADP_DP_CS_8, 1);
2977 	if (ret)
2978 		return ret;
2979 
2980 	if (!(val & ADP_DP_CS_8_DR))
2981 		return -ENODATA;
2982 
2983 	return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
2984 }
2985 
2986 /**
2987  * usb4_pci_port_set_ext_encapsulation() - Enable/disable extended encapsulation
2988  * @port: PCIe adapter
2989  * @enable: Enable/disable extended encapsulation
2990  *
2991  * Enables or disables extended encapsulation used in PCIe tunneling. Caller
2992  * needs to make sure both adapters support this before enabling. Returns %0 on
2993  * success and negative errno otherwise.
2994  */
2995 int usb4_pci_port_set_ext_encapsulation(struct tb_port *port, bool enable)
2996 {
2997 	u32 val;
2998 	int ret;
2999 
3000 	if (!tb_port_is_pcie_up(port) && !tb_port_is_pcie_down(port))
3001 		return -EINVAL;
3002 
3003 	ret = tb_port_read(port, &val, TB_CFG_PORT,
3004 			   port->cap_adap + ADP_PCIE_CS_1, 1);
3005 	if (ret)
3006 		return ret;
3007 
3008 	if (enable)
3009 		val |= ADP_PCIE_CS_1_EE;
3010 	else
3011 		val &= ~ADP_PCIE_CS_1_EE;
3012 
3013 	return tb_port_write(port, &val, TB_CFG_PORT,
3014 			     port->cap_adap + ADP_PCIE_CS_1, 1);
3015 }
3016