xref: /openbmc/linux/drivers/soundwire/bus.c (revision 75020f2d)
1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-17 Intel Corporation.
3 
4 #include <linux/acpi.h>
5 #include <linux/delay.h>
6 #include <linux/mod_devicetable.h>
7 #include <linux/pm_runtime.h>
8 #include <linux/soundwire/sdw_registers.h>
9 #include <linux/soundwire/sdw.h>
10 #include "bus.h"
11 #include "sysfs_local.h"
12 
13 static DEFINE_IDA(sdw_ida);
14 
15 static int sdw_get_id(struct sdw_bus *bus)
16 {
17 	int rc = ida_alloc(&sdw_ida, GFP_KERNEL);
18 
19 	if (rc < 0)
20 		return rc;
21 
22 	bus->id = rc;
23 	return 0;
24 }
25 
26 /**
27  * sdw_bus_master_add() - add a bus Master instance
28  * @bus: bus instance
29  * @parent: parent device
30  * @fwnode: firmware node handle
31  *
32  * Initializes the bus instance, read properties and create child
33  * devices.
34  */
35 int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
36 		       struct fwnode_handle *fwnode)
37 {
38 	struct sdw_master_prop *prop = NULL;
39 	int ret;
40 
41 	if (!parent) {
42 		pr_err("SoundWire parent device is not set\n");
43 		return -ENODEV;
44 	}
45 
46 	ret = sdw_get_id(bus);
47 	if (ret < 0) {
48 		dev_err(parent, "Failed to get bus id\n");
49 		return ret;
50 	}
51 
52 	ret = sdw_master_device_add(bus, parent, fwnode);
53 	if (ret < 0) {
54 		dev_err(parent, "Failed to add master device at link %d\n",
55 			bus->link_id);
56 		return ret;
57 	}
58 
59 	if (!bus->ops) {
60 		dev_err(bus->dev, "SoundWire Bus ops are not set\n");
61 		return -EINVAL;
62 	}
63 
64 	if (!bus->compute_params) {
65 		dev_err(bus->dev,
66 			"Bandwidth allocation not configured, compute_params no set\n");
67 		return -EINVAL;
68 	}
69 
70 	mutex_init(&bus->msg_lock);
71 	mutex_init(&bus->bus_lock);
72 	INIT_LIST_HEAD(&bus->slaves);
73 	INIT_LIST_HEAD(&bus->m_rt_list);
74 
75 	/*
76 	 * Initialize multi_link flag
77 	 * TODO: populate this flag by reading property from FW node
78 	 */
79 	bus->multi_link = false;
80 	if (bus->ops->read_prop) {
81 		ret = bus->ops->read_prop(bus);
82 		if (ret < 0) {
83 			dev_err(bus->dev,
84 				"Bus read properties failed:%d\n", ret);
85 			return ret;
86 		}
87 	}
88 
89 	sdw_bus_debugfs_init(bus);
90 
91 	/*
92 	 * Device numbers in SoundWire are 0 through 15. Enumeration device
93 	 * number (0), Broadcast device number (15), Group numbers (12 and
94 	 * 13) and Master device number (14) are not used for assignment so
95 	 * mask these and other higher bits.
96 	 */
97 
98 	/* Set higher order bits */
99 	*bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
100 
101 	/* Set enumuration device number and broadcast device number */
102 	set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
103 	set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
104 
105 	/* Set group device numbers and master device number */
106 	set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
107 	set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
108 	set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
109 
110 	/*
111 	 * SDW is an enumerable bus, but devices can be powered off. So,
112 	 * they won't be able to report as present.
113 	 *
114 	 * Create Slave devices based on Slaves described in
115 	 * the respective firmware (ACPI/DT)
116 	 */
117 	if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
118 		ret = sdw_acpi_find_slaves(bus);
119 	else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
120 		ret = sdw_of_find_slaves(bus);
121 	else
122 		ret = -ENOTSUPP; /* No ACPI/DT so error out */
123 
124 	if (ret < 0) {
125 		dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
126 		return ret;
127 	}
128 
129 	/*
130 	 * Initialize clock values based on Master properties. The max
131 	 * frequency is read from max_clk_freq property. Current assumption
132 	 * is that the bus will start at highest clock frequency when
133 	 * powered on.
134 	 *
135 	 * Default active bank will be 0 as out of reset the Slaves have
136 	 * to start with bank 0 (Table 40 of Spec)
137 	 */
138 	prop = &bus->prop;
139 	bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
140 	bus->params.curr_dr_freq = bus->params.max_dr_freq;
141 	bus->params.curr_bank = SDW_BANK0;
142 	bus->params.next_bank = SDW_BANK1;
143 
144 	return 0;
145 }
146 EXPORT_SYMBOL(sdw_bus_master_add);
147 
148 static int sdw_delete_slave(struct device *dev, void *data)
149 {
150 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
151 	struct sdw_bus *bus = slave->bus;
152 
153 	pm_runtime_disable(dev);
154 
155 	sdw_slave_debugfs_exit(slave);
156 
157 	mutex_lock(&bus->bus_lock);
158 
159 	if (slave->dev_num) /* clear dev_num if assigned */
160 		clear_bit(slave->dev_num, bus->assigned);
161 
162 	list_del_init(&slave->node);
163 	mutex_unlock(&bus->bus_lock);
164 
165 	device_unregister(dev);
166 	return 0;
167 }
168 
169 /**
170  * sdw_bus_master_delete() - delete the bus master instance
171  * @bus: bus to be deleted
172  *
173  * Remove the instance, delete the child devices.
174  */
175 void sdw_bus_master_delete(struct sdw_bus *bus)
176 {
177 	device_for_each_child(bus->dev, NULL, sdw_delete_slave);
178 	sdw_master_device_del(bus);
179 
180 	sdw_bus_debugfs_exit(bus);
181 	ida_free(&sdw_ida, bus->id);
182 }
183 EXPORT_SYMBOL(sdw_bus_master_delete);
184 
185 /*
186  * SDW IO Calls
187  */
188 
189 static inline int find_response_code(enum sdw_command_response resp)
190 {
191 	switch (resp) {
192 	case SDW_CMD_OK:
193 		return 0;
194 
195 	case SDW_CMD_IGNORED:
196 		return -ENODATA;
197 
198 	case SDW_CMD_TIMEOUT:
199 		return -ETIMEDOUT;
200 
201 	default:
202 		return -EIO;
203 	}
204 }
205 
206 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
207 {
208 	int retry = bus->prop.err_threshold;
209 	enum sdw_command_response resp;
210 	int ret = 0, i;
211 
212 	for (i = 0; i <= retry; i++) {
213 		resp = bus->ops->xfer_msg(bus, msg);
214 		ret = find_response_code(resp);
215 
216 		/* if cmd is ok or ignored return */
217 		if (ret == 0 || ret == -ENODATA)
218 			return ret;
219 	}
220 
221 	return ret;
222 }
223 
224 static inline int do_transfer_defer(struct sdw_bus *bus,
225 				    struct sdw_msg *msg,
226 				    struct sdw_defer *defer)
227 {
228 	int retry = bus->prop.err_threshold;
229 	enum sdw_command_response resp;
230 	int ret = 0, i;
231 
232 	defer->msg = msg;
233 	defer->length = msg->len;
234 	init_completion(&defer->complete);
235 
236 	for (i = 0; i <= retry; i++) {
237 		resp = bus->ops->xfer_msg_defer(bus, msg, defer);
238 		ret = find_response_code(resp);
239 		/* if cmd is ok or ignored return */
240 		if (ret == 0 || ret == -ENODATA)
241 			return ret;
242 	}
243 
244 	return ret;
245 }
246 
247 static int sdw_reset_page(struct sdw_bus *bus, u16 dev_num)
248 {
249 	int retry = bus->prop.err_threshold;
250 	enum sdw_command_response resp;
251 	int ret = 0, i;
252 
253 	for (i = 0; i <= retry; i++) {
254 		resp = bus->ops->reset_page_addr(bus, dev_num);
255 		ret = find_response_code(resp);
256 		/* if cmd is ok or ignored return */
257 		if (ret == 0 || ret == -ENODATA)
258 			return ret;
259 	}
260 
261 	return ret;
262 }
263 
264 static int sdw_transfer_unlocked(struct sdw_bus *bus, struct sdw_msg *msg)
265 {
266 	int ret;
267 
268 	ret = do_transfer(bus, msg);
269 	if (ret != 0 && ret != -ENODATA)
270 		dev_err(bus->dev, "trf on Slave %d failed:%d %s addr %x count %d\n",
271 			msg->dev_num, ret,
272 			(msg->flags & SDW_MSG_FLAG_WRITE) ? "write" : "read",
273 			msg->addr, msg->len);
274 
275 	if (msg->page)
276 		sdw_reset_page(bus, msg->dev_num);
277 
278 	return ret;
279 }
280 
281 /**
282  * sdw_transfer() - Synchronous transfer message to a SDW Slave device
283  * @bus: SDW bus
284  * @msg: SDW message to be xfered
285  */
286 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
287 {
288 	int ret;
289 
290 	mutex_lock(&bus->msg_lock);
291 
292 	ret = sdw_transfer_unlocked(bus, msg);
293 
294 	mutex_unlock(&bus->msg_lock);
295 
296 	return ret;
297 }
298 
299 /**
300  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
301  * @bus: SDW bus
302  * @msg: SDW message to be xfered
303  * @defer: Defer block for signal completion
304  *
305  * Caller needs to hold the msg_lock lock while calling this
306  */
307 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg,
308 		       struct sdw_defer *defer)
309 {
310 	int ret;
311 
312 	if (!bus->ops->xfer_msg_defer)
313 		return -ENOTSUPP;
314 
315 	ret = do_transfer_defer(bus, msg, defer);
316 	if (ret != 0 && ret != -ENODATA)
317 		dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
318 			msg->dev_num, ret);
319 
320 	if (msg->page)
321 		sdw_reset_page(bus, msg->dev_num);
322 
323 	return ret;
324 }
325 
326 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
327 		 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
328 {
329 	memset(msg, 0, sizeof(*msg));
330 	msg->addr = addr; /* addr is 16 bit and truncated here */
331 	msg->len = count;
332 	msg->dev_num = dev_num;
333 	msg->flags = flags;
334 	msg->buf = buf;
335 
336 	if (addr < SDW_REG_NO_PAGE) /* no paging area */
337 		return 0;
338 
339 	if (addr >= SDW_REG_MAX) { /* illegal addr */
340 		pr_err("SDW: Invalid address %x passed\n", addr);
341 		return -EINVAL;
342 	}
343 
344 	if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
345 		if (slave && !slave->prop.paging_support)
346 			return 0;
347 		/* no need for else as that will fall-through to paging */
348 	}
349 
350 	/* paging mandatory */
351 	if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
352 		pr_err("SDW: Invalid device for paging :%d\n", dev_num);
353 		return -EINVAL;
354 	}
355 
356 	if (!slave) {
357 		pr_err("SDW: No slave for paging addr\n");
358 		return -EINVAL;
359 	}
360 
361 	if (!slave->prop.paging_support) {
362 		dev_err(&slave->dev,
363 			"address %x needs paging but no support\n", addr);
364 		return -EINVAL;
365 	}
366 
367 	msg->addr_page1 = FIELD_GET(SDW_SCP_ADDRPAGE1_MASK, addr);
368 	msg->addr_page2 = FIELD_GET(SDW_SCP_ADDRPAGE2_MASK, addr);
369 	msg->addr |= BIT(15);
370 	msg->page = true;
371 
372 	return 0;
373 }
374 
375 /*
376  * Read/Write IO functions.
377  * no_pm versions can only be called by the bus, e.g. while enumerating or
378  * handling suspend-resume sequences.
379  * all clients need to use the pm versions
380  */
381 
382 static int
383 sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
384 {
385 	struct sdw_msg msg;
386 	int ret;
387 
388 	ret = sdw_fill_msg(&msg, slave, addr, count,
389 			   slave->dev_num, SDW_MSG_FLAG_READ, val);
390 	if (ret < 0)
391 		return ret;
392 
393 	return sdw_transfer(slave->bus, &msg);
394 }
395 
396 static int
397 sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
398 {
399 	struct sdw_msg msg;
400 	int ret;
401 
402 	ret = sdw_fill_msg(&msg, slave, addr, count,
403 			   slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val);
404 	if (ret < 0)
405 		return ret;
406 
407 	return sdw_transfer(slave->bus, &msg);
408 }
409 
410 int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
411 {
412 	return sdw_nwrite_no_pm(slave, addr, 1, &value);
413 }
414 EXPORT_SYMBOL(sdw_write_no_pm);
415 
416 static int
417 sdw_bread_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr)
418 {
419 	struct sdw_msg msg;
420 	u8 buf;
421 	int ret;
422 
423 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
424 			   SDW_MSG_FLAG_READ, &buf);
425 	if (ret < 0)
426 		return ret;
427 
428 	ret = sdw_transfer(bus, &msg);
429 	if (ret < 0)
430 		return ret;
431 
432 	return buf;
433 }
434 
435 static int
436 sdw_bwrite_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
437 {
438 	struct sdw_msg msg;
439 	int ret;
440 
441 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
442 			   SDW_MSG_FLAG_WRITE, &value);
443 	if (ret < 0)
444 		return ret;
445 
446 	return sdw_transfer(bus, &msg);
447 }
448 
449 int sdw_bread_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr)
450 {
451 	struct sdw_msg msg;
452 	u8 buf;
453 	int ret;
454 
455 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
456 			   SDW_MSG_FLAG_READ, &buf);
457 	if (ret < 0)
458 		return ret;
459 
460 	ret = sdw_transfer_unlocked(bus, &msg);
461 	if (ret < 0)
462 		return ret;
463 
464 	return buf;
465 }
466 EXPORT_SYMBOL(sdw_bread_no_pm_unlocked);
467 
468 int sdw_bwrite_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
469 {
470 	struct sdw_msg msg;
471 	int ret;
472 
473 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
474 			   SDW_MSG_FLAG_WRITE, &value);
475 	if (ret < 0)
476 		return ret;
477 
478 	return sdw_transfer_unlocked(bus, &msg);
479 }
480 EXPORT_SYMBOL(sdw_bwrite_no_pm_unlocked);
481 
482 int sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
483 {
484 	u8 buf;
485 	int ret;
486 
487 	ret = sdw_nread_no_pm(slave, addr, 1, &buf);
488 	if (ret < 0)
489 		return ret;
490 	else
491 		return buf;
492 }
493 EXPORT_SYMBOL(sdw_read_no_pm);
494 
495 static int sdw_update_no_pm(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
496 {
497 	int tmp;
498 
499 	tmp = sdw_read_no_pm(slave, addr);
500 	if (tmp < 0)
501 		return tmp;
502 
503 	tmp = (tmp & ~mask) | val;
504 	return sdw_write_no_pm(slave, addr, tmp);
505 }
506 
507 /**
508  * sdw_nread() - Read "n" contiguous SDW Slave registers
509  * @slave: SDW Slave
510  * @addr: Register address
511  * @count: length
512  * @val: Buffer for values to be read
513  */
514 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
515 {
516 	int ret;
517 
518 	ret = pm_runtime_get_sync(&slave->dev);
519 	if (ret < 0 && ret != -EACCES) {
520 		pm_runtime_put_noidle(&slave->dev);
521 		return ret;
522 	}
523 
524 	ret = sdw_nread_no_pm(slave, addr, count, val);
525 
526 	pm_runtime_mark_last_busy(&slave->dev);
527 	pm_runtime_put(&slave->dev);
528 
529 	return ret;
530 }
531 EXPORT_SYMBOL(sdw_nread);
532 
533 /**
534  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
535  * @slave: SDW Slave
536  * @addr: Register address
537  * @count: length
538  * @val: Buffer for values to be written
539  */
540 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
541 {
542 	int ret;
543 
544 	ret = pm_runtime_get_sync(&slave->dev);
545 	if (ret < 0 && ret != -EACCES) {
546 		pm_runtime_put_noidle(&slave->dev);
547 		return ret;
548 	}
549 
550 	ret = sdw_nwrite_no_pm(slave, addr, count, val);
551 
552 	pm_runtime_mark_last_busy(&slave->dev);
553 	pm_runtime_put(&slave->dev);
554 
555 	return ret;
556 }
557 EXPORT_SYMBOL(sdw_nwrite);
558 
559 /**
560  * sdw_read() - Read a SDW Slave register
561  * @slave: SDW Slave
562  * @addr: Register address
563  */
564 int sdw_read(struct sdw_slave *slave, u32 addr)
565 {
566 	u8 buf;
567 	int ret;
568 
569 	ret = sdw_nread(slave, addr, 1, &buf);
570 	if (ret < 0)
571 		return ret;
572 
573 	return buf;
574 }
575 EXPORT_SYMBOL(sdw_read);
576 
577 /**
578  * sdw_write() - Write a SDW Slave register
579  * @slave: SDW Slave
580  * @addr: Register address
581  * @value: Register value
582  */
583 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
584 {
585 	return sdw_nwrite(slave, addr, 1, &value);
586 }
587 EXPORT_SYMBOL(sdw_write);
588 
589 /*
590  * SDW alert handling
591  */
592 
593 /* called with bus_lock held */
594 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
595 {
596 	struct sdw_slave *slave;
597 
598 	list_for_each_entry(slave, &bus->slaves, node) {
599 		if (slave->dev_num == i)
600 			return slave;
601 	}
602 
603 	return NULL;
604 }
605 
606 int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
607 {
608 	if (slave->id.mfg_id != id.mfg_id ||
609 	    slave->id.part_id != id.part_id ||
610 	    slave->id.class_id != id.class_id ||
611 	    (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
612 	     slave->id.unique_id != id.unique_id))
613 		return -ENODEV;
614 
615 	return 0;
616 }
617 EXPORT_SYMBOL(sdw_compare_devid);
618 
619 /* called with bus_lock held */
620 static int sdw_get_device_num(struct sdw_slave *slave)
621 {
622 	int bit;
623 
624 	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
625 	if (bit == SDW_MAX_DEVICES) {
626 		bit = -ENODEV;
627 		goto err;
628 	}
629 
630 	/*
631 	 * Do not update dev_num in Slave data structure here,
632 	 * Update once program dev_num is successful
633 	 */
634 	set_bit(bit, slave->bus->assigned);
635 
636 err:
637 	return bit;
638 }
639 
640 static int sdw_assign_device_num(struct sdw_slave *slave)
641 {
642 	struct sdw_bus *bus = slave->bus;
643 	int ret, dev_num;
644 	bool new_device = false;
645 
646 	/* check first if device number is assigned, if so reuse that */
647 	if (!slave->dev_num) {
648 		if (!slave->dev_num_sticky) {
649 			mutex_lock(&slave->bus->bus_lock);
650 			dev_num = sdw_get_device_num(slave);
651 			mutex_unlock(&slave->bus->bus_lock);
652 			if (dev_num < 0) {
653 				dev_err(bus->dev, "Get dev_num failed: %d\n",
654 					dev_num);
655 				return dev_num;
656 			}
657 			slave->dev_num = dev_num;
658 			slave->dev_num_sticky = dev_num;
659 			new_device = true;
660 		} else {
661 			slave->dev_num = slave->dev_num_sticky;
662 		}
663 	}
664 
665 	if (!new_device)
666 		dev_dbg(bus->dev,
667 			"Slave already registered, reusing dev_num:%d\n",
668 			slave->dev_num);
669 
670 	/* Clear the slave->dev_num to transfer message on device 0 */
671 	dev_num = slave->dev_num;
672 	slave->dev_num = 0;
673 
674 	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
675 	if (ret < 0) {
676 		dev_err(bus->dev, "Program device_num %d failed: %d\n",
677 			dev_num, ret);
678 		return ret;
679 	}
680 
681 	/* After xfer of msg, restore dev_num */
682 	slave->dev_num = slave->dev_num_sticky;
683 
684 	return 0;
685 }
686 
687 void sdw_extract_slave_id(struct sdw_bus *bus,
688 			  u64 addr, struct sdw_slave_id *id)
689 {
690 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
691 
692 	id->sdw_version = SDW_VERSION(addr);
693 	id->unique_id = SDW_UNIQUE_ID(addr);
694 	id->mfg_id = SDW_MFG_ID(addr);
695 	id->part_id = SDW_PART_ID(addr);
696 	id->class_id = SDW_CLASS_ID(addr);
697 
698 	dev_dbg(bus->dev,
699 		"SDW Slave class_id 0x%02x, mfg_id 0x%04x, part_id 0x%04x, unique_id 0x%x, version 0x%x\n",
700 		id->class_id, id->mfg_id, id->part_id, id->unique_id, id->sdw_version);
701 }
702 EXPORT_SYMBOL(sdw_extract_slave_id);
703 
704 static int sdw_program_device_num(struct sdw_bus *bus)
705 {
706 	u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
707 	struct sdw_slave *slave, *_s;
708 	struct sdw_slave_id id;
709 	struct sdw_msg msg;
710 	bool found;
711 	int count = 0, ret;
712 	u64 addr;
713 
714 	/* No Slave, so use raw xfer api */
715 	ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
716 			   SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
717 	if (ret < 0)
718 		return ret;
719 
720 	do {
721 		ret = sdw_transfer(bus, &msg);
722 		if (ret == -ENODATA) { /* end of device id reads */
723 			dev_dbg(bus->dev, "No more devices to enumerate\n");
724 			ret = 0;
725 			break;
726 		}
727 		if (ret < 0) {
728 			dev_err(bus->dev, "DEVID read fail:%d\n", ret);
729 			break;
730 		}
731 
732 		/*
733 		 * Construct the addr and extract. Cast the higher shift
734 		 * bits to avoid truncation due to size limit.
735 		 */
736 		addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
737 			((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
738 			((u64)buf[0] << 40);
739 
740 		sdw_extract_slave_id(bus, addr, &id);
741 
742 		found = false;
743 		/* Now compare with entries */
744 		list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
745 			if (sdw_compare_devid(slave, id) == 0) {
746 				found = true;
747 
748 				/*
749 				 * Assign a new dev_num to this Slave and
750 				 * not mark it present. It will be marked
751 				 * present after it reports ATTACHED on new
752 				 * dev_num
753 				 */
754 				ret = sdw_assign_device_num(slave);
755 				if (ret < 0) {
756 					dev_err(bus->dev,
757 						"Assign dev_num failed:%d\n",
758 						ret);
759 					return ret;
760 				}
761 
762 				break;
763 			}
764 		}
765 
766 		if (!found) {
767 			/* TODO: Park this device in Group 13 */
768 
769 			/*
770 			 * add Slave device even if there is no platform
771 			 * firmware description. There will be no driver probe
772 			 * but the user/integration will be able to see the
773 			 * device, enumeration status and device number in sysfs
774 			 */
775 			sdw_slave_add(bus, &id, NULL);
776 
777 			dev_err(bus->dev, "Slave Entry not found\n");
778 		}
779 
780 		count++;
781 
782 		/*
783 		 * Check till error out or retry (count) exhausts.
784 		 * Device can drop off and rejoin during enumeration
785 		 * so count till twice the bound.
786 		 */
787 
788 	} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
789 
790 	return ret;
791 }
792 
793 static void sdw_modify_slave_status(struct sdw_slave *slave,
794 				    enum sdw_slave_status status)
795 {
796 	struct sdw_bus *bus = slave->bus;
797 
798 	mutex_lock(&bus->bus_lock);
799 
800 	dev_vdbg(bus->dev,
801 		 "%s: changing status slave %d status %d new status %d\n",
802 		 __func__, slave->dev_num, slave->status, status);
803 
804 	if (status == SDW_SLAVE_UNATTACHED) {
805 		dev_dbg(&slave->dev,
806 			"%s: initializing enumeration and init completion for Slave %d\n",
807 			__func__, slave->dev_num);
808 
809 		init_completion(&slave->enumeration_complete);
810 		init_completion(&slave->initialization_complete);
811 
812 	} else if ((status == SDW_SLAVE_ATTACHED) &&
813 		   (slave->status == SDW_SLAVE_UNATTACHED)) {
814 		dev_dbg(&slave->dev,
815 			"%s: signaling enumeration completion for Slave %d\n",
816 			__func__, slave->dev_num);
817 
818 		complete(&slave->enumeration_complete);
819 	}
820 	slave->status = status;
821 	mutex_unlock(&bus->bus_lock);
822 }
823 
824 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
825 				       enum sdw_clk_stop_mode mode,
826 				       enum sdw_clk_stop_type type)
827 {
828 	int ret;
829 
830 	if (slave->ops && slave->ops->clk_stop) {
831 		ret = slave->ops->clk_stop(slave, mode, type);
832 		if (ret < 0)
833 			return ret;
834 	}
835 
836 	return 0;
837 }
838 
839 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
840 				      enum sdw_clk_stop_mode mode,
841 				      bool prepare)
842 {
843 	bool wake_en;
844 	u32 val = 0;
845 	int ret;
846 
847 	wake_en = slave->prop.wake_capable;
848 
849 	if (prepare) {
850 		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
851 
852 		if (mode == SDW_CLK_STOP_MODE1)
853 			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
854 
855 		if (wake_en)
856 			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
857 	} else {
858 		ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
859 		if (ret < 0) {
860 			if (ret != -ENODATA)
861 				dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
862 			return ret;
863 		}
864 		val = ret;
865 		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
866 	}
867 
868 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
869 
870 	if (ret < 0 && ret != -ENODATA)
871 		dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL write failed:%d\n", ret);
872 
873 	return ret;
874 }
875 
876 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
877 {
878 	int retry = bus->clk_stop_timeout;
879 	int val;
880 
881 	do {
882 		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT);
883 		if (val < 0) {
884 			dev_err(bus->dev, "SDW_SCP_STAT bread failed:%d\n", val);
885 			return val;
886 		}
887 		val &= SDW_SCP_STAT_CLK_STP_NF;
888 		if (!val) {
889 			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d\n",
890 				dev_num);
891 			return 0;
892 		}
893 
894 		usleep_range(1000, 1500);
895 		retry--;
896 	} while (retry);
897 
898 	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d\n",
899 		dev_num);
900 
901 	return -ETIMEDOUT;
902 }
903 
904 /**
905  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
906  *
907  * @bus: SDW bus instance
908  *
909  * Query Slave for clock stop mode and prepare for that mode.
910  */
911 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
912 {
913 	bool simple_clk_stop = true;
914 	struct sdw_slave *slave;
915 	bool is_slave = false;
916 	int ret = 0;
917 
918 	/*
919 	 * In order to save on transition time, prepare
920 	 * each Slave and then wait for all Slave(s) to be
921 	 * prepared for clock stop.
922 	 * If one of the Slave devices has lost sync and
923 	 * replies with Command Ignored/-ENODATA, we continue
924 	 * the loop
925 	 */
926 	list_for_each_entry(slave, &bus->slaves, node) {
927 		if (!slave->dev_num)
928 			continue;
929 
930 		if (slave->status != SDW_SLAVE_ATTACHED &&
931 		    slave->status != SDW_SLAVE_ALERT)
932 			continue;
933 
934 		/* Identify if Slave(s) are available on Bus */
935 		is_slave = true;
936 
937 		ret = sdw_slave_clk_stop_callback(slave,
938 						  SDW_CLK_STOP_MODE0,
939 						  SDW_CLK_PRE_PREPARE);
940 		if (ret < 0 && ret != -ENODATA) {
941 			dev_err(&slave->dev, "clock stop pre-prepare cb failed:%d\n", ret);
942 			return ret;
943 		}
944 
945 		/* Only prepare a Slave device if needed */
946 		if (!slave->prop.simple_clk_stop_capable) {
947 			simple_clk_stop = false;
948 
949 			ret = sdw_slave_clk_stop_prepare(slave,
950 							 SDW_CLK_STOP_MODE0,
951 							 true);
952 			if (ret < 0 && ret != -ENODATA) {
953 				dev_err(&slave->dev, "clock stop prepare failed:%d\n", ret);
954 				return ret;
955 			}
956 		}
957 	}
958 
959 	/* Skip remaining clock stop preparation if no Slave is attached */
960 	if (!is_slave)
961 		return 0;
962 
963 	/*
964 	 * Don't wait for all Slaves to be ready if they follow the simple
965 	 * state machine
966 	 */
967 	if (!simple_clk_stop) {
968 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
969 						       SDW_BROADCAST_DEV_NUM);
970 		/*
971 		 * if there are no Slave devices present and the reply is
972 		 * Command_Ignored/-ENODATA, we don't need to continue with the
973 		 * flow and can just return here. The error code is not modified
974 		 * and its handling left as an exercise for the caller.
975 		 */
976 		if (ret < 0)
977 			return ret;
978 	}
979 
980 	/* Inform slaves that prep is done */
981 	list_for_each_entry(slave, &bus->slaves, node) {
982 		if (!slave->dev_num)
983 			continue;
984 
985 		if (slave->status != SDW_SLAVE_ATTACHED &&
986 		    slave->status != SDW_SLAVE_ALERT)
987 			continue;
988 
989 		ret = sdw_slave_clk_stop_callback(slave,
990 						  SDW_CLK_STOP_MODE0,
991 						  SDW_CLK_POST_PREPARE);
992 
993 		if (ret < 0 && ret != -ENODATA) {
994 			dev_err(&slave->dev, "clock stop post-prepare cb failed:%d\n", ret);
995 			return ret;
996 		}
997 	}
998 
999 	return 0;
1000 }
1001 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
1002 
1003 /**
1004  * sdw_bus_clk_stop: stop bus clock
1005  *
1006  * @bus: SDW bus instance
1007  *
1008  * After preparing the Slaves for clock stop, stop the clock by broadcasting
1009  * write to SCP_CTRL register.
1010  */
1011 int sdw_bus_clk_stop(struct sdw_bus *bus)
1012 {
1013 	int ret;
1014 
1015 	/*
1016 	 * broadcast clock stop now, attached Slaves will ACK this,
1017 	 * unattached will ignore
1018 	 */
1019 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1020 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1021 	if (ret < 0) {
1022 		if (ret != -ENODATA)
1023 			dev_err(bus->dev, "ClockStopNow Broadcast msg failed %d\n", ret);
1024 		return ret;
1025 	}
1026 
1027 	return 0;
1028 }
1029 EXPORT_SYMBOL(sdw_bus_clk_stop);
1030 
1031 /**
1032  * sdw_bus_exit_clk_stop: Exit clock stop mode
1033  *
1034  * @bus: SDW bus instance
1035  *
1036  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1037  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1038  * back.
1039  */
1040 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1041 {
1042 	bool simple_clk_stop = true;
1043 	struct sdw_slave *slave;
1044 	bool is_slave = false;
1045 	int ret;
1046 
1047 	/*
1048 	 * In order to save on transition time, de-prepare
1049 	 * each Slave and then wait for all Slave(s) to be
1050 	 * de-prepared after clock resume.
1051 	 */
1052 	list_for_each_entry(slave, &bus->slaves, node) {
1053 		if (!slave->dev_num)
1054 			continue;
1055 
1056 		if (slave->status != SDW_SLAVE_ATTACHED &&
1057 		    slave->status != SDW_SLAVE_ALERT)
1058 			continue;
1059 
1060 		/* Identify if Slave(s) are available on Bus */
1061 		is_slave = true;
1062 
1063 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1064 						  SDW_CLK_PRE_DEPREPARE);
1065 		if (ret < 0)
1066 			dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);
1067 
1068 		/* Only de-prepare a Slave device if needed */
1069 		if (!slave->prop.simple_clk_stop_capable) {
1070 			simple_clk_stop = false;
1071 
1072 			ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
1073 							 false);
1074 
1075 			if (ret < 0)
1076 				dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret);
1077 		}
1078 	}
1079 
1080 	/* Skip remaining clock stop de-preparation if no Slave is attached */
1081 	if (!is_slave)
1082 		return 0;
1083 
1084 	/*
1085 	 * Don't wait for all Slaves to be ready if they follow the simple
1086 	 * state machine
1087 	 */
1088 	if (!simple_clk_stop) {
1089 		ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1090 		if (ret < 0)
1091 			dev_warn(&slave->dev, "clock stop deprepare wait failed:%d\n", ret);
1092 	}
1093 
1094 	list_for_each_entry(slave, &bus->slaves, node) {
1095 		if (!slave->dev_num)
1096 			continue;
1097 
1098 		if (slave->status != SDW_SLAVE_ATTACHED &&
1099 		    slave->status != SDW_SLAVE_ALERT)
1100 			continue;
1101 
1102 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1103 						  SDW_CLK_POST_DEPREPARE);
1104 		if (ret < 0)
1105 			dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret);
1106 	}
1107 
1108 	return 0;
1109 }
1110 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1111 
1112 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1113 			   int port, bool enable, int mask)
1114 {
1115 	u32 addr;
1116 	int ret;
1117 	u8 val = 0;
1118 
1119 	if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1120 		dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1121 			enable ? "on" : "off");
1122 		mask |= SDW_DPN_INT_TEST_FAIL;
1123 	}
1124 
1125 	addr = SDW_DPN_INTMASK(port);
1126 
1127 	/* Set/Clear port ready interrupt mask */
1128 	if (enable) {
1129 		val |= mask;
1130 		val |= SDW_DPN_INT_PORT_READY;
1131 	} else {
1132 		val &= ~(mask);
1133 		val &= ~SDW_DPN_INT_PORT_READY;
1134 	}
1135 
1136 	ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1137 	if (ret < 0)
1138 		dev_err(&slave->dev,
1139 			"SDW_DPN_INTMASK write failed:%d\n", val);
1140 
1141 	return ret;
1142 }
1143 
1144 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1145 {
1146 	u32 mclk_freq = slave->bus->prop.mclk_freq;
1147 	u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1148 	unsigned int scale;
1149 	u8 scale_index;
1150 	u8 base;
1151 	int ret;
1152 
1153 	/*
1154 	 * frequency base and scale registers are required for SDCA
1155 	 * devices. They may also be used for 1.2+/non-SDCA devices,
1156 	 * but we will need a DisCo property to cover this case
1157 	 */
1158 	if (!slave->id.class_id)
1159 		return 0;
1160 
1161 	if (!mclk_freq) {
1162 		dev_err(&slave->dev,
1163 			"no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1164 		return -EINVAL;
1165 	}
1166 
1167 	/*
1168 	 * map base frequency using Table 89 of SoundWire 1.2 spec.
1169 	 * The order of the tests just follows the specification, this
1170 	 * is not a selection between possible values or a search for
1171 	 * the best value but just a mapping.  Only one case per platform
1172 	 * is relevant.
1173 	 * Some BIOS have inconsistent values for mclk_freq but a
1174 	 * correct root so we force the mclk_freq to avoid variations.
1175 	 */
1176 	if (!(19200000 % mclk_freq)) {
1177 		mclk_freq = 19200000;
1178 		base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1179 	} else if (!(24000000 % mclk_freq)) {
1180 		mclk_freq = 24000000;
1181 		base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1182 	} else if (!(24576000 % mclk_freq)) {
1183 		mclk_freq = 24576000;
1184 		base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1185 	} else if (!(22579200 % mclk_freq)) {
1186 		mclk_freq = 22579200;
1187 		base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1188 	} else if (!(32000000 % mclk_freq)) {
1189 		mclk_freq = 32000000;
1190 		base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1191 	} else {
1192 		dev_err(&slave->dev,
1193 			"Unsupported clock base, mclk %d\n",
1194 			mclk_freq);
1195 		return -EINVAL;
1196 	}
1197 
1198 	if (mclk_freq % curr_freq) {
1199 		dev_err(&slave->dev,
1200 			"mclk %d is not multiple of bus curr_freq %d\n",
1201 			mclk_freq, curr_freq);
1202 		return -EINVAL;
1203 	}
1204 
1205 	scale = mclk_freq / curr_freq;
1206 
1207 	/*
1208 	 * map scale to Table 90 of SoundWire 1.2 spec - and check
1209 	 * that the scale is a power of two and maximum 64
1210 	 */
1211 	scale_index = ilog2(scale);
1212 
1213 	if (BIT(scale_index) != scale || scale_index > 6) {
1214 		dev_err(&slave->dev,
1215 			"No match found for scale %d, bus mclk %d curr_freq %d\n",
1216 			scale, mclk_freq, curr_freq);
1217 		return -EINVAL;
1218 	}
1219 	scale_index++;
1220 
1221 	ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1222 	if (ret < 0) {
1223 		dev_err(&slave->dev,
1224 			"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1225 		return ret;
1226 	}
1227 
1228 	/* initialize scale for both banks */
1229 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1230 	if (ret < 0) {
1231 		dev_err(&slave->dev,
1232 			"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1233 		return ret;
1234 	}
1235 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1236 	if (ret < 0)
1237 		dev_err(&slave->dev,
1238 			"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1239 
1240 	dev_dbg(&slave->dev,
1241 		"Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1242 		base, scale_index, mclk_freq, curr_freq);
1243 
1244 	return ret;
1245 }
1246 
1247 static int sdw_initialize_slave(struct sdw_slave *slave)
1248 {
1249 	struct sdw_slave_prop *prop = &slave->prop;
1250 	int status;
1251 	int ret;
1252 	u8 val;
1253 
1254 	ret = sdw_slave_set_frequency(slave);
1255 	if (ret < 0)
1256 		return ret;
1257 
1258 	if (slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH) {
1259 		/* Clear bus clash interrupt before enabling interrupt mask */
1260 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1261 		if (status < 0) {
1262 			dev_err(&slave->dev,
1263 				"SDW_SCP_INT1 (BUS_CLASH) read failed:%d\n", status);
1264 			return status;
1265 		}
1266 		if (status & SDW_SCP_INT1_BUS_CLASH) {
1267 			dev_warn(&slave->dev, "Bus clash detected before INT mask is enabled\n");
1268 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH);
1269 			if (ret < 0) {
1270 				dev_err(&slave->dev,
1271 					"SDW_SCP_INT1 (BUS_CLASH) write failed:%d\n", ret);
1272 				return ret;
1273 			}
1274 		}
1275 	}
1276 	if ((slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY) &&
1277 	    !(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY)) {
1278 		/* Clear parity interrupt before enabling interrupt mask */
1279 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1280 		if (status < 0) {
1281 			dev_err(&slave->dev,
1282 				"SDW_SCP_INT1 (PARITY) read failed:%d\n", status);
1283 			return status;
1284 		}
1285 		if (status & SDW_SCP_INT1_PARITY) {
1286 			dev_warn(&slave->dev, "PARITY error detected before INT mask is enabled\n");
1287 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_PARITY);
1288 			if (ret < 0) {
1289 				dev_err(&slave->dev,
1290 					"SDW_SCP_INT1 (PARITY) write failed:%d\n", ret);
1291 				return ret;
1292 			}
1293 		}
1294 	}
1295 
1296 	/*
1297 	 * Set SCP_INT1_MASK register, typically bus clash and
1298 	 * implementation-defined interrupt mask. The Parity detection
1299 	 * may not always be correct on startup so its use is
1300 	 * device-dependent, it might e.g. only be enabled in
1301 	 * steady-state after a couple of frames.
1302 	 */
1303 	val = slave->prop.scp_int1_mask;
1304 
1305 	/* Enable SCP interrupts */
1306 	ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
1307 	if (ret < 0) {
1308 		dev_err(&slave->dev,
1309 			"SDW_SCP_INTMASK1 write failed:%d\n", ret);
1310 		return ret;
1311 	}
1312 
1313 	/* No need to continue if DP0 is not present */
1314 	if (!slave->prop.dp0_prop)
1315 		return 0;
1316 
1317 	/* Enable DP0 interrupts */
1318 	val = prop->dp0_prop->imp_def_interrupts;
1319 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1320 
1321 	ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
1322 	if (ret < 0)
1323 		dev_err(&slave->dev,
1324 			"SDW_DP0_INTMASK read failed:%d\n", ret);
1325 	return ret;
1326 }
1327 
1328 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1329 {
1330 	u8 clear, impl_int_mask;
1331 	int status, status2, ret, count = 0;
1332 
1333 	status = sdw_read_no_pm(slave, SDW_DP0_INT);
1334 	if (status < 0) {
1335 		dev_err(&slave->dev,
1336 			"SDW_DP0_INT read failed:%d\n", status);
1337 		return status;
1338 	}
1339 
1340 	do {
1341 		clear = status & ~SDW_DP0_INTERRUPTS;
1342 
1343 		if (status & SDW_DP0_INT_TEST_FAIL) {
1344 			dev_err(&slave->dev, "Test fail for port 0\n");
1345 			clear |= SDW_DP0_INT_TEST_FAIL;
1346 		}
1347 
1348 		/*
1349 		 * Assumption: PORT_READY interrupt will be received only for
1350 		 * ports implementing Channel Prepare state machine (CP_SM)
1351 		 */
1352 
1353 		if (status & SDW_DP0_INT_PORT_READY) {
1354 			complete(&slave->port_ready[0]);
1355 			clear |= SDW_DP0_INT_PORT_READY;
1356 		}
1357 
1358 		if (status & SDW_DP0_INT_BRA_FAILURE) {
1359 			dev_err(&slave->dev, "BRA failed\n");
1360 			clear |= SDW_DP0_INT_BRA_FAILURE;
1361 		}
1362 
1363 		impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1364 			SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1365 
1366 		if (status & impl_int_mask) {
1367 			clear |= impl_int_mask;
1368 			*slave_status = clear;
1369 		}
1370 
1371 		/* clear the interrupts but don't touch reserved and SDCA_CASCADE fields */
1372 		ret = sdw_write_no_pm(slave, SDW_DP0_INT, clear);
1373 		if (ret < 0) {
1374 			dev_err(&slave->dev,
1375 				"SDW_DP0_INT write failed:%d\n", ret);
1376 			return ret;
1377 		}
1378 
1379 		/* Read DP0 interrupt again */
1380 		status2 = sdw_read_no_pm(slave, SDW_DP0_INT);
1381 		if (status2 < 0) {
1382 			dev_err(&slave->dev,
1383 				"SDW_DP0_INT read failed:%d\n", status2);
1384 			return status2;
1385 		}
1386 		/* filter to limit loop to interrupts identified in the first status read */
1387 		status &= status2;
1388 
1389 		count++;
1390 
1391 		/* we can get alerts while processing so keep retrying */
1392 	} while ((status & SDW_DP0_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1393 
1394 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1395 		dev_warn(&slave->dev, "Reached MAX_RETRY on DP0 read\n");
1396 
1397 	return ret;
1398 }
1399 
1400 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1401 				     int port, u8 *slave_status)
1402 {
1403 	u8 clear, impl_int_mask;
1404 	int status, status2, ret, count = 0;
1405 	u32 addr;
1406 
1407 	if (port == 0)
1408 		return sdw_handle_dp0_interrupt(slave, slave_status);
1409 
1410 	addr = SDW_DPN_INT(port);
1411 	status = sdw_read_no_pm(slave, addr);
1412 	if (status < 0) {
1413 		dev_err(&slave->dev,
1414 			"SDW_DPN_INT read failed:%d\n", status);
1415 
1416 		return status;
1417 	}
1418 
1419 	do {
1420 		clear = status & ~SDW_DPN_INTERRUPTS;
1421 
1422 		if (status & SDW_DPN_INT_TEST_FAIL) {
1423 			dev_err(&slave->dev, "Test fail for port:%d\n", port);
1424 			clear |= SDW_DPN_INT_TEST_FAIL;
1425 		}
1426 
1427 		/*
1428 		 * Assumption: PORT_READY interrupt will be received only
1429 		 * for ports implementing CP_SM.
1430 		 */
1431 		if (status & SDW_DPN_INT_PORT_READY) {
1432 			complete(&slave->port_ready[port]);
1433 			clear |= SDW_DPN_INT_PORT_READY;
1434 		}
1435 
1436 		impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1437 			SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1438 
1439 		if (status & impl_int_mask) {
1440 			clear |= impl_int_mask;
1441 			*slave_status = clear;
1442 		}
1443 
1444 		/* clear the interrupt but don't touch reserved fields */
1445 		ret = sdw_write_no_pm(slave, addr, clear);
1446 		if (ret < 0) {
1447 			dev_err(&slave->dev,
1448 				"SDW_DPN_INT write failed:%d\n", ret);
1449 			return ret;
1450 		}
1451 
1452 		/* Read DPN interrupt again */
1453 		status2 = sdw_read_no_pm(slave, addr);
1454 		if (status2 < 0) {
1455 			dev_err(&slave->dev,
1456 				"SDW_DPN_INT read failed:%d\n", status2);
1457 			return status2;
1458 		}
1459 		/* filter to limit loop to interrupts identified in the first status read */
1460 		status &= status2;
1461 
1462 		count++;
1463 
1464 		/* we can get alerts while processing so keep retrying */
1465 	} while ((status & SDW_DPN_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1466 
1467 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1468 		dev_warn(&slave->dev, "Reached MAX_RETRY on port read");
1469 
1470 	return ret;
1471 }
1472 
1473 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1474 {
1475 	struct sdw_slave_intr_status slave_intr;
1476 	u8 clear = 0, bit, port_status[15] = {0};
1477 	int port_num, stat, ret, count = 0;
1478 	unsigned long port;
1479 	bool slave_notify;
1480 	u8 sdca_cascade = 0;
1481 	u8 buf, buf2[2], _buf, _buf2[2];
1482 	bool parity_check;
1483 	bool parity_quirk;
1484 
1485 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1486 
1487 	ret = pm_runtime_get_sync(&slave->dev);
1488 	if (ret < 0 && ret != -EACCES) {
1489 		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
1490 		pm_runtime_put_noidle(&slave->dev);
1491 		return ret;
1492 	}
1493 
1494 	/* Read Intstat 1, Intstat 2 and Intstat 3 registers */
1495 	ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1496 	if (ret < 0) {
1497 		dev_err(&slave->dev,
1498 			"SDW_SCP_INT1 read failed:%d\n", ret);
1499 		goto io_err;
1500 	}
1501 	buf = ret;
1502 
1503 	ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, buf2);
1504 	if (ret < 0) {
1505 		dev_err(&slave->dev,
1506 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
1507 		goto io_err;
1508 	}
1509 
1510 	if (slave->prop.is_sdca) {
1511 		ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1512 		if (ret < 0) {
1513 			dev_err(&slave->dev,
1514 				"SDW_DP0_INT read failed:%d\n", ret);
1515 			goto io_err;
1516 		}
1517 		sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1518 	}
1519 
1520 	do {
1521 		slave_notify = false;
1522 
1523 		/*
1524 		 * Check parity, bus clash and Slave (impl defined)
1525 		 * interrupt
1526 		 */
1527 		if (buf & SDW_SCP_INT1_PARITY) {
1528 			parity_check = slave->prop.scp_int1_mask & SDW_SCP_INT1_PARITY;
1529 			parity_quirk = !slave->first_interrupt_done &&
1530 				(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY);
1531 
1532 			if (parity_check && !parity_quirk)
1533 				dev_err(&slave->dev, "Parity error detected\n");
1534 			clear |= SDW_SCP_INT1_PARITY;
1535 		}
1536 
1537 		if (buf & SDW_SCP_INT1_BUS_CLASH) {
1538 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_BUS_CLASH)
1539 				dev_err(&slave->dev, "Bus clash detected\n");
1540 			clear |= SDW_SCP_INT1_BUS_CLASH;
1541 		}
1542 
1543 		/*
1544 		 * When bus clash or parity errors are detected, such errors
1545 		 * are unlikely to be recoverable errors.
1546 		 * TODO: In such scenario, reset bus. Make this configurable
1547 		 * via sysfs property with bus reset being the default.
1548 		 */
1549 
1550 		if (buf & SDW_SCP_INT1_IMPL_DEF) {
1551 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_IMPL_DEF) {
1552 				dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
1553 				slave_notify = true;
1554 			}
1555 			clear |= SDW_SCP_INT1_IMPL_DEF;
1556 		}
1557 
1558 		/* the SDCA interrupts are cleared in the codec driver .interrupt_callback() */
1559 		if (sdca_cascade)
1560 			slave_notify = true;
1561 
1562 		/* Check port 0 - 3 interrupts */
1563 		port = buf & SDW_SCP_INT1_PORT0_3;
1564 
1565 		/* To get port number corresponding to bits, shift it */
1566 		port = FIELD_GET(SDW_SCP_INT1_PORT0_3, port);
1567 		for_each_set_bit(bit, &port, 8) {
1568 			sdw_handle_port_interrupt(slave, bit,
1569 						  &port_status[bit]);
1570 		}
1571 
1572 		/* Check if cascade 2 interrupt is present */
1573 		if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
1574 			port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
1575 			for_each_set_bit(bit, &port, 8) {
1576 				/* scp2 ports start from 4 */
1577 				port_num = bit + 3;
1578 				sdw_handle_port_interrupt(slave,
1579 						port_num,
1580 						&port_status[port_num]);
1581 			}
1582 		}
1583 
1584 		/* now check last cascade */
1585 		if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
1586 			port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
1587 			for_each_set_bit(bit, &port, 8) {
1588 				/* scp3 ports start from 11 */
1589 				port_num = bit + 10;
1590 				sdw_handle_port_interrupt(slave,
1591 						port_num,
1592 						&port_status[port_num]);
1593 			}
1594 		}
1595 
1596 		/* Update the Slave driver */
1597 		if (slave_notify && slave->ops &&
1598 		    slave->ops->interrupt_callback) {
1599 			slave_intr.sdca_cascade = sdca_cascade;
1600 			slave_intr.control_port = clear;
1601 			memcpy(slave_intr.port, &port_status,
1602 			       sizeof(slave_intr.port));
1603 
1604 			slave->ops->interrupt_callback(slave, &slave_intr);
1605 		}
1606 
1607 		/* Ack interrupt */
1608 		ret = sdw_write_no_pm(slave, SDW_SCP_INT1, clear);
1609 		if (ret < 0) {
1610 			dev_err(&slave->dev,
1611 				"SDW_SCP_INT1 write failed:%d\n", ret);
1612 			goto io_err;
1613 		}
1614 
1615 		/* at this point all initial interrupt sources were handled */
1616 		slave->first_interrupt_done = true;
1617 
1618 		/*
1619 		 * Read status again to ensure no new interrupts arrived
1620 		 * while servicing interrupts.
1621 		 */
1622 		ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1623 		if (ret < 0) {
1624 			dev_err(&slave->dev,
1625 				"SDW_SCP_INT1 recheck read failed:%d\n", ret);
1626 			goto io_err;
1627 		}
1628 		_buf = ret;
1629 
1630 		ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, _buf2);
1631 		if (ret < 0) {
1632 			dev_err(&slave->dev,
1633 				"SDW_SCP_INT2/3 recheck read failed:%d\n", ret);
1634 			goto io_err;
1635 		}
1636 
1637 		if (slave->prop.is_sdca) {
1638 			ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1639 			if (ret < 0) {
1640 				dev_err(&slave->dev,
1641 					"SDW_DP0_INT recheck read failed:%d\n", ret);
1642 				goto io_err;
1643 			}
1644 			sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1645 		}
1646 
1647 		/*
1648 		 * Make sure no interrupts are pending, but filter to limit loop
1649 		 * to interrupts identified in the first status read
1650 		 */
1651 		buf &= _buf;
1652 		buf2[0] &= _buf2[0];
1653 		buf2[1] &= _buf2[1];
1654 		stat = buf || buf2[0] || buf2[1] || sdca_cascade;
1655 
1656 		/*
1657 		 * Exit loop if Slave is continuously in ALERT state even
1658 		 * after servicing the interrupt multiple times.
1659 		 */
1660 		count++;
1661 
1662 		/* we can get alerts while processing so keep retrying */
1663 	} while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1664 
1665 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1666 		dev_warn(&slave->dev, "Reached MAX_RETRY on alert read\n");
1667 
1668 io_err:
1669 	pm_runtime_mark_last_busy(&slave->dev);
1670 	pm_runtime_put_autosuspend(&slave->dev);
1671 
1672 	return ret;
1673 }
1674 
1675 static int sdw_update_slave_status(struct sdw_slave *slave,
1676 				   enum sdw_slave_status status)
1677 {
1678 	unsigned long time;
1679 
1680 	if (!slave->probed) {
1681 		/*
1682 		 * the slave status update is typically handled in an
1683 		 * interrupt thread, which can race with the driver
1684 		 * probe, e.g. when a module needs to be loaded.
1685 		 *
1686 		 * make sure the probe is complete before updating
1687 		 * status.
1688 		 */
1689 		time = wait_for_completion_timeout(&slave->probe_complete,
1690 				msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
1691 		if (!time) {
1692 			dev_err(&slave->dev, "Probe not complete, timed out\n");
1693 			return -ETIMEDOUT;
1694 		}
1695 	}
1696 
1697 	if (!slave->ops || !slave->ops->update_status)
1698 		return 0;
1699 
1700 	return slave->ops->update_status(slave, status);
1701 }
1702 
1703 /**
1704  * sdw_handle_slave_status() - Handle Slave status
1705  * @bus: SDW bus instance
1706  * @status: Status for all Slave(s)
1707  */
1708 int sdw_handle_slave_status(struct sdw_bus *bus,
1709 			    enum sdw_slave_status status[])
1710 {
1711 	enum sdw_slave_status prev_status;
1712 	struct sdw_slave *slave;
1713 	bool attached_initializing;
1714 	int i, ret = 0;
1715 
1716 	/* first check if any Slaves fell off the bus */
1717 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1718 		mutex_lock(&bus->bus_lock);
1719 		if (test_bit(i, bus->assigned) == false) {
1720 			mutex_unlock(&bus->bus_lock);
1721 			continue;
1722 		}
1723 		mutex_unlock(&bus->bus_lock);
1724 
1725 		slave = sdw_get_slave(bus, i);
1726 		if (!slave)
1727 			continue;
1728 
1729 		if (status[i] == SDW_SLAVE_UNATTACHED &&
1730 		    slave->status != SDW_SLAVE_UNATTACHED)
1731 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1732 	}
1733 
1734 	if (status[0] == SDW_SLAVE_ATTACHED) {
1735 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
1736 		ret = sdw_program_device_num(bus);
1737 		if (ret < 0)
1738 			dev_err(bus->dev, "Slave attach failed: %d\n", ret);
1739 		/*
1740 		 * programming a device number will have side effects,
1741 		 * so we deal with other devices at a later time
1742 		 */
1743 		return ret;
1744 	}
1745 
1746 	/* Continue to check other slave statuses */
1747 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1748 		mutex_lock(&bus->bus_lock);
1749 		if (test_bit(i, bus->assigned) == false) {
1750 			mutex_unlock(&bus->bus_lock);
1751 			continue;
1752 		}
1753 		mutex_unlock(&bus->bus_lock);
1754 
1755 		slave = sdw_get_slave(bus, i);
1756 		if (!slave)
1757 			continue;
1758 
1759 		attached_initializing = false;
1760 
1761 		switch (status[i]) {
1762 		case SDW_SLAVE_UNATTACHED:
1763 			if (slave->status == SDW_SLAVE_UNATTACHED)
1764 				break;
1765 
1766 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1767 			break;
1768 
1769 		case SDW_SLAVE_ALERT:
1770 			ret = sdw_handle_slave_alerts(slave);
1771 			if (ret < 0)
1772 				dev_err(&slave->dev,
1773 					"Slave %d alert handling failed: %d\n",
1774 					i, ret);
1775 			break;
1776 
1777 		case SDW_SLAVE_ATTACHED:
1778 			if (slave->status == SDW_SLAVE_ATTACHED)
1779 				break;
1780 
1781 			prev_status = slave->status;
1782 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1783 
1784 			if (prev_status == SDW_SLAVE_ALERT)
1785 				break;
1786 
1787 			attached_initializing = true;
1788 
1789 			ret = sdw_initialize_slave(slave);
1790 			if (ret < 0)
1791 				dev_err(&slave->dev,
1792 					"Slave %d initialization failed: %d\n",
1793 					i, ret);
1794 
1795 			break;
1796 
1797 		default:
1798 			dev_err(&slave->dev, "Invalid slave %d status:%d\n",
1799 				i, status[i]);
1800 			break;
1801 		}
1802 
1803 		ret = sdw_update_slave_status(slave, status[i]);
1804 		if (ret < 0)
1805 			dev_err(&slave->dev,
1806 				"Update Slave status failed:%d\n", ret);
1807 		if (attached_initializing) {
1808 			dev_dbg(&slave->dev,
1809 				"%s: signaling initialization completion for Slave %d\n",
1810 				__func__, slave->dev_num);
1811 
1812 			complete(&slave->initialization_complete);
1813 		}
1814 	}
1815 
1816 	return ret;
1817 }
1818 EXPORT_SYMBOL(sdw_handle_slave_status);
1819 
1820 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1821 {
1822 	struct sdw_slave *slave;
1823 	int i;
1824 
1825 	/* Check all non-zero devices */
1826 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1827 		mutex_lock(&bus->bus_lock);
1828 		if (test_bit(i, bus->assigned) == false) {
1829 			mutex_unlock(&bus->bus_lock);
1830 			continue;
1831 		}
1832 		mutex_unlock(&bus->bus_lock);
1833 
1834 		slave = sdw_get_slave(bus, i);
1835 		if (!slave)
1836 			continue;
1837 
1838 		if (slave->status != SDW_SLAVE_UNATTACHED) {
1839 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1840 			slave->first_interrupt_done = false;
1841 		}
1842 
1843 		/* keep track of request, used in pm_runtime resume */
1844 		slave->unattach_request = request;
1845 	}
1846 }
1847 EXPORT_SYMBOL(sdw_clear_slave_status);
1848