xref: /linux/drivers/soundwire/bus.c (revision aaa44952bbd1d4db14a4d676bf9595bb5db7e7b0)
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, 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, 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 read
539  */
540 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, 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 enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave)
825 {
826 	enum sdw_clk_stop_mode mode;
827 
828 	/*
829 	 * Query for clock stop mode if Slave implements
830 	 * ops->get_clk_stop_mode, else read from property.
831 	 */
832 	if (slave->ops && slave->ops->get_clk_stop_mode) {
833 		mode = slave->ops->get_clk_stop_mode(slave);
834 	} else {
835 		if (slave->prop.clk_stop_mode1)
836 			mode = SDW_CLK_STOP_MODE1;
837 		else
838 			mode = SDW_CLK_STOP_MODE0;
839 	}
840 
841 	return mode;
842 }
843 
844 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
845 				       enum sdw_clk_stop_mode mode,
846 				       enum sdw_clk_stop_type type)
847 {
848 	int ret;
849 
850 	if (slave->ops && slave->ops->clk_stop) {
851 		ret = slave->ops->clk_stop(slave, mode, type);
852 		if (ret < 0) {
853 			dev_err(&slave->dev,
854 				"Clk Stop type =%d failed: %d\n", type, ret);
855 			return ret;
856 		}
857 	}
858 
859 	return 0;
860 }
861 
862 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
863 				      enum sdw_clk_stop_mode mode,
864 				      bool prepare)
865 {
866 	bool wake_en;
867 	u32 val = 0;
868 	int ret;
869 
870 	wake_en = slave->prop.wake_capable;
871 
872 	if (prepare) {
873 		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
874 
875 		if (mode == SDW_CLK_STOP_MODE1)
876 			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
877 
878 		if (wake_en)
879 			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
880 	} else {
881 		ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
882 		if (ret < 0) {
883 			dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
884 			return ret;
885 		}
886 		val = ret;
887 		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
888 	}
889 
890 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
891 
892 	if (ret < 0)
893 		dev_err(&slave->dev,
894 			"Clock Stop prepare failed for slave: %d", ret);
895 
896 	return ret;
897 }
898 
899 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
900 {
901 	int retry = bus->clk_stop_timeout;
902 	int val;
903 
904 	do {
905 		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT);
906 		if (val < 0) {
907 			dev_err(bus->dev, "SDW_SCP_STAT bread failed:%d\n", val);
908 			return val;
909 		}
910 		val &= SDW_SCP_STAT_CLK_STP_NF;
911 		if (!val) {
912 			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d",
913 				dev_num);
914 			return 0;
915 		}
916 
917 		usleep_range(1000, 1500);
918 		retry--;
919 	} while (retry);
920 
921 	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d",
922 		dev_num);
923 
924 	return -ETIMEDOUT;
925 }
926 
927 /**
928  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
929  *
930  * @bus: SDW bus instance
931  *
932  * Query Slave for clock stop mode and prepare for that mode.
933  */
934 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
935 {
936 	enum sdw_clk_stop_mode slave_mode;
937 	bool simple_clk_stop = true;
938 	struct sdw_slave *slave;
939 	bool is_slave = false;
940 	int ret = 0;
941 
942 	/*
943 	 * In order to save on transition time, prepare
944 	 * each Slave and then wait for all Slave(s) to be
945 	 * prepared for clock stop.
946 	 */
947 	list_for_each_entry(slave, &bus->slaves, node) {
948 		if (!slave->dev_num)
949 			continue;
950 
951 		if (slave->status != SDW_SLAVE_ATTACHED &&
952 		    slave->status != SDW_SLAVE_ALERT)
953 			continue;
954 
955 		/* Identify if Slave(s) are available on Bus */
956 		is_slave = true;
957 
958 		slave_mode = sdw_get_clk_stop_mode(slave);
959 		slave->curr_clk_stop_mode = slave_mode;
960 
961 		ret = sdw_slave_clk_stop_callback(slave, slave_mode,
962 						  SDW_CLK_PRE_PREPARE);
963 		if (ret < 0) {
964 			dev_err(&slave->dev,
965 				"pre-prepare failed:%d", ret);
966 			return ret;
967 		}
968 
969 		ret = sdw_slave_clk_stop_prepare(slave,
970 						 slave_mode, true);
971 		if (ret < 0) {
972 			dev_err(&slave->dev,
973 				"pre-prepare failed:%d", ret);
974 			return ret;
975 		}
976 
977 		if (slave_mode == SDW_CLK_STOP_MODE1)
978 			simple_clk_stop = false;
979 	}
980 
981 	/* Skip remaining clock stop preparation if no Slave is attached */
982 	if (!is_slave)
983 		return ret;
984 
985 	if (!simple_clk_stop) {
986 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
987 						       SDW_BROADCAST_DEV_NUM);
988 		if (ret < 0)
989 			return ret;
990 	}
991 
992 	/* Inform slaves that prep is done */
993 	list_for_each_entry(slave, &bus->slaves, node) {
994 		if (!slave->dev_num)
995 			continue;
996 
997 		if (slave->status != SDW_SLAVE_ATTACHED &&
998 		    slave->status != SDW_SLAVE_ALERT)
999 			continue;
1000 
1001 		slave_mode = slave->curr_clk_stop_mode;
1002 
1003 		if (slave_mode == SDW_CLK_STOP_MODE1) {
1004 			ret = sdw_slave_clk_stop_callback(slave,
1005 							  slave_mode,
1006 							  SDW_CLK_POST_PREPARE);
1007 
1008 			if (ret < 0) {
1009 				dev_err(&slave->dev,
1010 					"post-prepare failed:%d", ret);
1011 			}
1012 		}
1013 	}
1014 
1015 	return ret;
1016 }
1017 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
1018 
1019 /**
1020  * sdw_bus_clk_stop: stop bus clock
1021  *
1022  * @bus: SDW bus instance
1023  *
1024  * After preparing the Slaves for clock stop, stop the clock by broadcasting
1025  * write to SCP_CTRL register.
1026  */
1027 int sdw_bus_clk_stop(struct sdw_bus *bus)
1028 {
1029 	int ret;
1030 
1031 	/*
1032 	 * broadcast clock stop now, attached Slaves will ACK this,
1033 	 * unattached will ignore
1034 	 */
1035 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1036 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1037 	if (ret < 0) {
1038 		if (ret == -ENODATA)
1039 			dev_dbg(bus->dev,
1040 				"ClockStopNow Broadcast msg ignored %d", ret);
1041 		else
1042 			dev_err(bus->dev,
1043 				"ClockStopNow Broadcast msg failed %d", ret);
1044 		return ret;
1045 	}
1046 
1047 	return 0;
1048 }
1049 EXPORT_SYMBOL(sdw_bus_clk_stop);
1050 
1051 /**
1052  * sdw_bus_exit_clk_stop: Exit clock stop mode
1053  *
1054  * @bus: SDW bus instance
1055  *
1056  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1057  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1058  * back.
1059  */
1060 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1061 {
1062 	enum sdw_clk_stop_mode mode;
1063 	bool simple_clk_stop = true;
1064 	struct sdw_slave *slave;
1065 	bool is_slave = false;
1066 	int ret;
1067 
1068 	/*
1069 	 * In order to save on transition time, de-prepare
1070 	 * each Slave and then wait for all Slave(s) to be
1071 	 * de-prepared after clock resume.
1072 	 */
1073 	list_for_each_entry(slave, &bus->slaves, node) {
1074 		if (!slave->dev_num)
1075 			continue;
1076 
1077 		if (slave->status != SDW_SLAVE_ATTACHED &&
1078 		    slave->status != SDW_SLAVE_ALERT)
1079 			continue;
1080 
1081 		/* Identify if Slave(s) are available on Bus */
1082 		is_slave = true;
1083 
1084 		mode = slave->curr_clk_stop_mode;
1085 
1086 		if (mode == SDW_CLK_STOP_MODE1) {
1087 			simple_clk_stop = false;
1088 			continue;
1089 		}
1090 
1091 		ret = sdw_slave_clk_stop_callback(slave, mode,
1092 						  SDW_CLK_PRE_DEPREPARE);
1093 		if (ret < 0)
1094 			dev_warn(&slave->dev,
1095 				 "clk stop deprep failed:%d", ret);
1096 
1097 		ret = sdw_slave_clk_stop_prepare(slave, mode,
1098 						 false);
1099 
1100 		if (ret < 0)
1101 			dev_warn(&slave->dev,
1102 				 "clk stop deprep failed:%d", ret);
1103 	}
1104 
1105 	/* Skip remaining clock stop de-preparation if no Slave is attached */
1106 	if (!is_slave)
1107 		return 0;
1108 
1109 	if (!simple_clk_stop)
1110 		sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1111 
1112 	list_for_each_entry(slave, &bus->slaves, node) {
1113 		if (!slave->dev_num)
1114 			continue;
1115 
1116 		if (slave->status != SDW_SLAVE_ATTACHED &&
1117 		    slave->status != SDW_SLAVE_ALERT)
1118 			continue;
1119 
1120 		mode = slave->curr_clk_stop_mode;
1121 		sdw_slave_clk_stop_callback(slave, mode,
1122 					    SDW_CLK_POST_DEPREPARE);
1123 	}
1124 
1125 	return 0;
1126 }
1127 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1128 
1129 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1130 			   int port, bool enable, int mask)
1131 {
1132 	u32 addr;
1133 	int ret;
1134 	u8 val = 0;
1135 
1136 	if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1137 		dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1138 			enable ? "on" : "off");
1139 		mask |= SDW_DPN_INT_TEST_FAIL;
1140 	}
1141 
1142 	addr = SDW_DPN_INTMASK(port);
1143 
1144 	/* Set/Clear port ready interrupt mask */
1145 	if (enable) {
1146 		val |= mask;
1147 		val |= SDW_DPN_INT_PORT_READY;
1148 	} else {
1149 		val &= ~(mask);
1150 		val &= ~SDW_DPN_INT_PORT_READY;
1151 	}
1152 
1153 	ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1154 	if (ret < 0)
1155 		dev_err(&slave->dev,
1156 			"SDW_DPN_INTMASK write failed:%d\n", val);
1157 
1158 	return ret;
1159 }
1160 
1161 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1162 {
1163 	u32 mclk_freq = slave->bus->prop.mclk_freq;
1164 	u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1165 	unsigned int scale;
1166 	u8 scale_index;
1167 	u8 base;
1168 	int ret;
1169 
1170 	/*
1171 	 * frequency base and scale registers are required for SDCA
1172 	 * devices. They may also be used for 1.2+/non-SDCA devices,
1173 	 * but we will need a DisCo property to cover this case
1174 	 */
1175 	if (!slave->id.class_id)
1176 		return 0;
1177 
1178 	if (!mclk_freq) {
1179 		dev_err(&slave->dev,
1180 			"no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1181 		return -EINVAL;
1182 	}
1183 
1184 	/*
1185 	 * map base frequency using Table 89 of SoundWire 1.2 spec.
1186 	 * The order of the tests just follows the specification, this
1187 	 * is not a selection between possible values or a search for
1188 	 * the best value but just a mapping.  Only one case per platform
1189 	 * is relevant.
1190 	 * Some BIOS have inconsistent values for mclk_freq but a
1191 	 * correct root so we force the mclk_freq to avoid variations.
1192 	 */
1193 	if (!(19200000 % mclk_freq)) {
1194 		mclk_freq = 19200000;
1195 		base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1196 	} else if (!(24000000 % mclk_freq)) {
1197 		mclk_freq = 24000000;
1198 		base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1199 	} else if (!(24576000 % mclk_freq)) {
1200 		mclk_freq = 24576000;
1201 		base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1202 	} else if (!(22579200 % mclk_freq)) {
1203 		mclk_freq = 22579200;
1204 		base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1205 	} else if (!(32000000 % mclk_freq)) {
1206 		mclk_freq = 32000000;
1207 		base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1208 	} else {
1209 		dev_err(&slave->dev,
1210 			"Unsupported clock base, mclk %d\n",
1211 			mclk_freq);
1212 		return -EINVAL;
1213 	}
1214 
1215 	if (mclk_freq % curr_freq) {
1216 		dev_err(&slave->dev,
1217 			"mclk %d is not multiple of bus curr_freq %d\n",
1218 			mclk_freq, curr_freq);
1219 		return -EINVAL;
1220 	}
1221 
1222 	scale = mclk_freq / curr_freq;
1223 
1224 	/*
1225 	 * map scale to Table 90 of SoundWire 1.2 spec - and check
1226 	 * that the scale is a power of two and maximum 64
1227 	 */
1228 	scale_index = ilog2(scale);
1229 
1230 	if (BIT(scale_index) != scale || scale_index > 6) {
1231 		dev_err(&slave->dev,
1232 			"No match found for scale %d, bus mclk %d curr_freq %d\n",
1233 			scale, mclk_freq, curr_freq);
1234 		return -EINVAL;
1235 	}
1236 	scale_index++;
1237 
1238 	ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1239 	if (ret < 0) {
1240 		dev_err(&slave->dev,
1241 			"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1242 		return ret;
1243 	}
1244 
1245 	/* initialize scale for both banks */
1246 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1247 	if (ret < 0) {
1248 		dev_err(&slave->dev,
1249 			"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1250 		return ret;
1251 	}
1252 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1253 	if (ret < 0)
1254 		dev_err(&slave->dev,
1255 			"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1256 
1257 	dev_dbg(&slave->dev,
1258 		"Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1259 		base, scale_index, mclk_freq, curr_freq);
1260 
1261 	return ret;
1262 }
1263 
1264 static int sdw_initialize_slave(struct sdw_slave *slave)
1265 {
1266 	struct sdw_slave_prop *prop = &slave->prop;
1267 	int status;
1268 	int ret;
1269 	u8 val;
1270 
1271 	ret = sdw_slave_set_frequency(slave);
1272 	if (ret < 0)
1273 		return ret;
1274 
1275 	if (slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH) {
1276 		/* Clear bus clash interrupt before enabling interrupt mask */
1277 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1278 		if (status < 0) {
1279 			dev_err(&slave->dev,
1280 				"SDW_SCP_INT1 (BUS_CLASH) read failed:%d\n", status);
1281 			return status;
1282 		}
1283 		if (status & SDW_SCP_INT1_BUS_CLASH) {
1284 			dev_warn(&slave->dev, "Bus clash detected before INT mask is enabled\n");
1285 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH);
1286 			if (ret < 0) {
1287 				dev_err(&slave->dev,
1288 					"SDW_SCP_INT1 (BUS_CLASH) write failed:%d\n", ret);
1289 				return ret;
1290 			}
1291 		}
1292 	}
1293 	if ((slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY) &&
1294 	    !(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY)) {
1295 		/* Clear parity interrupt before enabling interrupt mask */
1296 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1297 		if (status < 0) {
1298 			dev_err(&slave->dev,
1299 				"SDW_SCP_INT1 (PARITY) read failed:%d\n", status);
1300 			return status;
1301 		}
1302 		if (status & SDW_SCP_INT1_PARITY) {
1303 			dev_warn(&slave->dev, "PARITY error detected before INT mask is enabled\n");
1304 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_PARITY);
1305 			if (ret < 0) {
1306 				dev_err(&slave->dev,
1307 					"SDW_SCP_INT1 (PARITY) write failed:%d\n", ret);
1308 				return ret;
1309 			}
1310 		}
1311 	}
1312 
1313 	/*
1314 	 * Set SCP_INT1_MASK register, typically bus clash and
1315 	 * implementation-defined interrupt mask. The Parity detection
1316 	 * may not always be correct on startup so its use is
1317 	 * device-dependent, it might e.g. only be enabled in
1318 	 * steady-state after a couple of frames.
1319 	 */
1320 	val = slave->prop.scp_int1_mask;
1321 
1322 	/* Enable SCP interrupts */
1323 	ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
1324 	if (ret < 0) {
1325 		dev_err(&slave->dev,
1326 			"SDW_SCP_INTMASK1 write failed:%d\n", ret);
1327 		return ret;
1328 	}
1329 
1330 	/* No need to continue if DP0 is not present */
1331 	if (!slave->prop.dp0_prop)
1332 		return 0;
1333 
1334 	/* Enable DP0 interrupts */
1335 	val = prop->dp0_prop->imp_def_interrupts;
1336 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1337 
1338 	ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
1339 	if (ret < 0)
1340 		dev_err(&slave->dev,
1341 			"SDW_DP0_INTMASK read failed:%d\n", ret);
1342 	return ret;
1343 }
1344 
1345 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1346 {
1347 	u8 clear, impl_int_mask;
1348 	int status, status2, ret, count = 0;
1349 
1350 	status = sdw_read_no_pm(slave, SDW_DP0_INT);
1351 	if (status < 0) {
1352 		dev_err(&slave->dev,
1353 			"SDW_DP0_INT read failed:%d\n", status);
1354 		return status;
1355 	}
1356 
1357 	do {
1358 		clear = status & ~SDW_DP0_INTERRUPTS;
1359 
1360 		if (status & SDW_DP0_INT_TEST_FAIL) {
1361 			dev_err(&slave->dev, "Test fail for port 0\n");
1362 			clear |= SDW_DP0_INT_TEST_FAIL;
1363 		}
1364 
1365 		/*
1366 		 * Assumption: PORT_READY interrupt will be received only for
1367 		 * ports implementing Channel Prepare state machine (CP_SM)
1368 		 */
1369 
1370 		if (status & SDW_DP0_INT_PORT_READY) {
1371 			complete(&slave->port_ready[0]);
1372 			clear |= SDW_DP0_INT_PORT_READY;
1373 		}
1374 
1375 		if (status & SDW_DP0_INT_BRA_FAILURE) {
1376 			dev_err(&slave->dev, "BRA failed\n");
1377 			clear |= SDW_DP0_INT_BRA_FAILURE;
1378 		}
1379 
1380 		impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1381 			SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1382 
1383 		if (status & impl_int_mask) {
1384 			clear |= impl_int_mask;
1385 			*slave_status = clear;
1386 		}
1387 
1388 		/* clear the interrupts but don't touch reserved and SDCA_CASCADE fields */
1389 		ret = sdw_write_no_pm(slave, SDW_DP0_INT, clear);
1390 		if (ret < 0) {
1391 			dev_err(&slave->dev,
1392 				"SDW_DP0_INT write failed:%d\n", ret);
1393 			return ret;
1394 		}
1395 
1396 		/* Read DP0 interrupt again */
1397 		status2 = sdw_read_no_pm(slave, SDW_DP0_INT);
1398 		if (status2 < 0) {
1399 			dev_err(&slave->dev,
1400 				"SDW_DP0_INT read failed:%d\n", status2);
1401 			return status2;
1402 		}
1403 		/* filter to limit loop to interrupts identified in the first status read */
1404 		status &= status2;
1405 
1406 		count++;
1407 
1408 		/* we can get alerts while processing so keep retrying */
1409 	} while ((status & SDW_DP0_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1410 
1411 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1412 		dev_warn(&slave->dev, "Reached MAX_RETRY on DP0 read\n");
1413 
1414 	return ret;
1415 }
1416 
1417 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1418 				     int port, u8 *slave_status)
1419 {
1420 	u8 clear, impl_int_mask;
1421 	int status, status2, ret, count = 0;
1422 	u32 addr;
1423 
1424 	if (port == 0)
1425 		return sdw_handle_dp0_interrupt(slave, slave_status);
1426 
1427 	addr = SDW_DPN_INT(port);
1428 	status = sdw_read_no_pm(slave, addr);
1429 	if (status < 0) {
1430 		dev_err(&slave->dev,
1431 			"SDW_DPN_INT read failed:%d\n", status);
1432 
1433 		return status;
1434 	}
1435 
1436 	do {
1437 		clear = status & ~SDW_DPN_INTERRUPTS;
1438 
1439 		if (status & SDW_DPN_INT_TEST_FAIL) {
1440 			dev_err(&slave->dev, "Test fail for port:%d\n", port);
1441 			clear |= SDW_DPN_INT_TEST_FAIL;
1442 		}
1443 
1444 		/*
1445 		 * Assumption: PORT_READY interrupt will be received only
1446 		 * for ports implementing CP_SM.
1447 		 */
1448 		if (status & SDW_DPN_INT_PORT_READY) {
1449 			complete(&slave->port_ready[port]);
1450 			clear |= SDW_DPN_INT_PORT_READY;
1451 		}
1452 
1453 		impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1454 			SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1455 
1456 		if (status & impl_int_mask) {
1457 			clear |= impl_int_mask;
1458 			*slave_status = clear;
1459 		}
1460 
1461 		/* clear the interrupt but don't touch reserved fields */
1462 		ret = sdw_write_no_pm(slave, addr, clear);
1463 		if (ret < 0) {
1464 			dev_err(&slave->dev,
1465 				"SDW_DPN_INT write failed:%d\n", ret);
1466 			return ret;
1467 		}
1468 
1469 		/* Read DPN interrupt again */
1470 		status2 = sdw_read_no_pm(slave, addr);
1471 		if (status2 < 0) {
1472 			dev_err(&slave->dev,
1473 				"SDW_DPN_INT read failed:%d\n", status2);
1474 			return status2;
1475 		}
1476 		/* filter to limit loop to interrupts identified in the first status read */
1477 		status &= status2;
1478 
1479 		count++;
1480 
1481 		/* we can get alerts while processing so keep retrying */
1482 	} while ((status & SDW_DPN_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1483 
1484 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1485 		dev_warn(&slave->dev, "Reached MAX_RETRY on port read");
1486 
1487 	return ret;
1488 }
1489 
1490 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1491 {
1492 	struct sdw_slave_intr_status slave_intr;
1493 	u8 clear = 0, bit, port_status[15] = {0};
1494 	int port_num, stat, ret, count = 0;
1495 	unsigned long port;
1496 	bool slave_notify;
1497 	u8 sdca_cascade = 0;
1498 	u8 buf, buf2[2], _buf, _buf2[2];
1499 	bool parity_check;
1500 	bool parity_quirk;
1501 
1502 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1503 
1504 	ret = pm_runtime_get_sync(&slave->dev);
1505 	if (ret < 0 && ret != -EACCES) {
1506 		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
1507 		pm_runtime_put_noidle(&slave->dev);
1508 		return ret;
1509 	}
1510 
1511 	/* Read Intstat 1, Intstat 2 and Intstat 3 registers */
1512 	ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1513 	if (ret < 0) {
1514 		dev_err(&slave->dev,
1515 			"SDW_SCP_INT1 read failed:%d\n", ret);
1516 		goto io_err;
1517 	}
1518 	buf = ret;
1519 
1520 	ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, buf2);
1521 	if (ret < 0) {
1522 		dev_err(&slave->dev,
1523 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
1524 		goto io_err;
1525 	}
1526 
1527 	if (slave->prop.is_sdca) {
1528 		ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1529 		if (ret < 0) {
1530 			dev_err(&slave->dev,
1531 				"SDW_DP0_INT read failed:%d\n", ret);
1532 			goto io_err;
1533 		}
1534 		sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1535 	}
1536 
1537 	do {
1538 		slave_notify = false;
1539 
1540 		/*
1541 		 * Check parity, bus clash and Slave (impl defined)
1542 		 * interrupt
1543 		 */
1544 		if (buf & SDW_SCP_INT1_PARITY) {
1545 			parity_check = slave->prop.scp_int1_mask & SDW_SCP_INT1_PARITY;
1546 			parity_quirk = !slave->first_interrupt_done &&
1547 				(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY);
1548 
1549 			if (parity_check && !parity_quirk)
1550 				dev_err(&slave->dev, "Parity error detected\n");
1551 			clear |= SDW_SCP_INT1_PARITY;
1552 		}
1553 
1554 		if (buf & SDW_SCP_INT1_BUS_CLASH) {
1555 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_BUS_CLASH)
1556 				dev_err(&slave->dev, "Bus clash detected\n");
1557 			clear |= SDW_SCP_INT1_BUS_CLASH;
1558 		}
1559 
1560 		/*
1561 		 * When bus clash or parity errors are detected, such errors
1562 		 * are unlikely to be recoverable errors.
1563 		 * TODO: In such scenario, reset bus. Make this configurable
1564 		 * via sysfs property with bus reset being the default.
1565 		 */
1566 
1567 		if (buf & SDW_SCP_INT1_IMPL_DEF) {
1568 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_IMPL_DEF) {
1569 				dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
1570 				slave_notify = true;
1571 			}
1572 			clear |= SDW_SCP_INT1_IMPL_DEF;
1573 		}
1574 
1575 		/* the SDCA interrupts are cleared in the codec driver .interrupt_callback() */
1576 		if (sdca_cascade)
1577 			slave_notify = true;
1578 
1579 		/* Check port 0 - 3 interrupts */
1580 		port = buf & SDW_SCP_INT1_PORT0_3;
1581 
1582 		/* To get port number corresponding to bits, shift it */
1583 		port = FIELD_GET(SDW_SCP_INT1_PORT0_3, port);
1584 		for_each_set_bit(bit, &port, 8) {
1585 			sdw_handle_port_interrupt(slave, bit,
1586 						  &port_status[bit]);
1587 		}
1588 
1589 		/* Check if cascade 2 interrupt is present */
1590 		if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
1591 			port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
1592 			for_each_set_bit(bit, &port, 8) {
1593 				/* scp2 ports start from 4 */
1594 				port_num = bit + 3;
1595 				sdw_handle_port_interrupt(slave,
1596 						port_num,
1597 						&port_status[port_num]);
1598 			}
1599 		}
1600 
1601 		/* now check last cascade */
1602 		if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
1603 			port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
1604 			for_each_set_bit(bit, &port, 8) {
1605 				/* scp3 ports start from 11 */
1606 				port_num = bit + 10;
1607 				sdw_handle_port_interrupt(slave,
1608 						port_num,
1609 						&port_status[port_num]);
1610 			}
1611 		}
1612 
1613 		/* Update the Slave driver */
1614 		if (slave_notify && slave->ops &&
1615 		    slave->ops->interrupt_callback) {
1616 			slave_intr.sdca_cascade = sdca_cascade;
1617 			slave_intr.control_port = clear;
1618 			memcpy(slave_intr.port, &port_status,
1619 			       sizeof(slave_intr.port));
1620 
1621 			slave->ops->interrupt_callback(slave, &slave_intr);
1622 		}
1623 
1624 		/* Ack interrupt */
1625 		ret = sdw_write_no_pm(slave, SDW_SCP_INT1, clear);
1626 		if (ret < 0) {
1627 			dev_err(&slave->dev,
1628 				"SDW_SCP_INT1 write failed:%d\n", ret);
1629 			goto io_err;
1630 		}
1631 
1632 		/* at this point all initial interrupt sources were handled */
1633 		slave->first_interrupt_done = true;
1634 
1635 		/*
1636 		 * Read status again to ensure no new interrupts arrived
1637 		 * while servicing interrupts.
1638 		 */
1639 		ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1640 		if (ret < 0) {
1641 			dev_err(&slave->dev,
1642 				"SDW_SCP_INT1 recheck read failed:%d\n", ret);
1643 			goto io_err;
1644 		}
1645 		_buf = ret;
1646 
1647 		ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, _buf2);
1648 		if (ret < 0) {
1649 			dev_err(&slave->dev,
1650 				"SDW_SCP_INT2/3 recheck read failed:%d\n", ret);
1651 			goto io_err;
1652 		}
1653 
1654 		if (slave->prop.is_sdca) {
1655 			ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1656 			if (ret < 0) {
1657 				dev_err(&slave->dev,
1658 					"SDW_DP0_INT recheck read failed:%d\n", ret);
1659 				goto io_err;
1660 			}
1661 			sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1662 		}
1663 
1664 		/*
1665 		 * Make sure no interrupts are pending, but filter to limit loop
1666 		 * to interrupts identified in the first status read
1667 		 */
1668 		buf &= _buf;
1669 		buf2[0] &= _buf2[0];
1670 		buf2[1] &= _buf2[1];
1671 		stat = buf || buf2[0] || buf2[1] || sdca_cascade;
1672 
1673 		/*
1674 		 * Exit loop if Slave is continuously in ALERT state even
1675 		 * after servicing the interrupt multiple times.
1676 		 */
1677 		count++;
1678 
1679 		/* we can get alerts while processing so keep retrying */
1680 	} while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1681 
1682 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1683 		dev_warn(&slave->dev, "Reached MAX_RETRY on alert read\n");
1684 
1685 io_err:
1686 	pm_runtime_mark_last_busy(&slave->dev);
1687 	pm_runtime_put_autosuspend(&slave->dev);
1688 
1689 	return ret;
1690 }
1691 
1692 static int sdw_update_slave_status(struct sdw_slave *slave,
1693 				   enum sdw_slave_status status)
1694 {
1695 	unsigned long time;
1696 
1697 	if (!slave->probed) {
1698 		/*
1699 		 * the slave status update is typically handled in an
1700 		 * interrupt thread, which can race with the driver
1701 		 * probe, e.g. when a module needs to be loaded.
1702 		 *
1703 		 * make sure the probe is complete before updating
1704 		 * status.
1705 		 */
1706 		time = wait_for_completion_timeout(&slave->probe_complete,
1707 				msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
1708 		if (!time) {
1709 			dev_err(&slave->dev, "Probe not complete, timed out\n");
1710 			return -ETIMEDOUT;
1711 		}
1712 	}
1713 
1714 	if (!slave->ops || !slave->ops->update_status)
1715 		return 0;
1716 
1717 	return slave->ops->update_status(slave, status);
1718 }
1719 
1720 /**
1721  * sdw_handle_slave_status() - Handle Slave status
1722  * @bus: SDW bus instance
1723  * @status: Status for all Slave(s)
1724  */
1725 int sdw_handle_slave_status(struct sdw_bus *bus,
1726 			    enum sdw_slave_status status[])
1727 {
1728 	enum sdw_slave_status prev_status;
1729 	struct sdw_slave *slave;
1730 	bool attached_initializing;
1731 	int i, ret = 0;
1732 
1733 	/* first check if any Slaves fell off the bus */
1734 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1735 		mutex_lock(&bus->bus_lock);
1736 		if (test_bit(i, bus->assigned) == false) {
1737 			mutex_unlock(&bus->bus_lock);
1738 			continue;
1739 		}
1740 		mutex_unlock(&bus->bus_lock);
1741 
1742 		slave = sdw_get_slave(bus, i);
1743 		if (!slave)
1744 			continue;
1745 
1746 		if (status[i] == SDW_SLAVE_UNATTACHED &&
1747 		    slave->status != SDW_SLAVE_UNATTACHED)
1748 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1749 	}
1750 
1751 	if (status[0] == SDW_SLAVE_ATTACHED) {
1752 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
1753 		ret = sdw_program_device_num(bus);
1754 		if (ret < 0)
1755 			dev_err(bus->dev, "Slave attach failed: %d\n", ret);
1756 		/*
1757 		 * programming a device number will have side effects,
1758 		 * so we deal with other devices at a later time
1759 		 */
1760 		return ret;
1761 	}
1762 
1763 	/* Continue to check other slave statuses */
1764 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1765 		mutex_lock(&bus->bus_lock);
1766 		if (test_bit(i, bus->assigned) == false) {
1767 			mutex_unlock(&bus->bus_lock);
1768 			continue;
1769 		}
1770 		mutex_unlock(&bus->bus_lock);
1771 
1772 		slave = sdw_get_slave(bus, i);
1773 		if (!slave)
1774 			continue;
1775 
1776 		attached_initializing = false;
1777 
1778 		switch (status[i]) {
1779 		case SDW_SLAVE_UNATTACHED:
1780 			if (slave->status == SDW_SLAVE_UNATTACHED)
1781 				break;
1782 
1783 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1784 			break;
1785 
1786 		case SDW_SLAVE_ALERT:
1787 			ret = sdw_handle_slave_alerts(slave);
1788 			if (ret < 0)
1789 				dev_err(&slave->dev,
1790 					"Slave %d alert handling failed: %d\n",
1791 					i, ret);
1792 			break;
1793 
1794 		case SDW_SLAVE_ATTACHED:
1795 			if (slave->status == SDW_SLAVE_ATTACHED)
1796 				break;
1797 
1798 			prev_status = slave->status;
1799 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1800 
1801 			if (prev_status == SDW_SLAVE_ALERT)
1802 				break;
1803 
1804 			attached_initializing = true;
1805 
1806 			ret = sdw_initialize_slave(slave);
1807 			if (ret < 0)
1808 				dev_err(&slave->dev,
1809 					"Slave %d initialization failed: %d\n",
1810 					i, ret);
1811 
1812 			break;
1813 
1814 		default:
1815 			dev_err(&slave->dev, "Invalid slave %d status:%d\n",
1816 				i, status[i]);
1817 			break;
1818 		}
1819 
1820 		ret = sdw_update_slave_status(slave, status[i]);
1821 		if (ret < 0)
1822 			dev_err(&slave->dev,
1823 				"Update Slave status failed:%d\n", ret);
1824 		if (attached_initializing) {
1825 			dev_dbg(&slave->dev,
1826 				"%s: signaling initialization completion for Slave %d\n",
1827 				__func__, slave->dev_num);
1828 
1829 			complete(&slave->initialization_complete);
1830 		}
1831 	}
1832 
1833 	return ret;
1834 }
1835 EXPORT_SYMBOL(sdw_handle_slave_status);
1836 
1837 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1838 {
1839 	struct sdw_slave *slave;
1840 	int i;
1841 
1842 	/* Check all non-zero devices */
1843 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1844 		mutex_lock(&bus->bus_lock);
1845 		if (test_bit(i, bus->assigned) == false) {
1846 			mutex_unlock(&bus->bus_lock);
1847 			continue;
1848 		}
1849 		mutex_unlock(&bus->bus_lock);
1850 
1851 		slave = sdw_get_slave(bus, i);
1852 		if (!slave)
1853 			continue;
1854 
1855 		if (slave->status != SDW_SLAVE_UNATTACHED) {
1856 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1857 			slave->first_interrupt_done = false;
1858 		}
1859 
1860 		/* keep track of request, used in pm_runtime resume */
1861 		slave->unattach_request = request;
1862 	}
1863 }
1864 EXPORT_SYMBOL(sdw_clear_slave_status);
1865