xref: /openbmc/linux/drivers/soundwire/bus.c (revision 6a143a7c)
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) {
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) {
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) {
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)
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)
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)
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)
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 = NULL;
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 static 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 
618 /* called with bus_lock held */
619 static int sdw_get_device_num(struct sdw_slave *slave)
620 {
621 	int bit;
622 
623 	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
624 	if (bit == SDW_MAX_DEVICES) {
625 		bit = -ENODEV;
626 		goto err;
627 	}
628 
629 	/*
630 	 * Do not update dev_num in Slave data structure here,
631 	 * Update once program dev_num is successful
632 	 */
633 	set_bit(bit, slave->bus->assigned);
634 
635 err:
636 	return bit;
637 }
638 
639 static int sdw_assign_device_num(struct sdw_slave *slave)
640 {
641 	struct sdw_bus *bus = slave->bus;
642 	int ret, dev_num;
643 	bool new_device = false;
644 
645 	/* check first if device number is assigned, if so reuse that */
646 	if (!slave->dev_num) {
647 		if (!slave->dev_num_sticky) {
648 			mutex_lock(&slave->bus->bus_lock);
649 			dev_num = sdw_get_device_num(slave);
650 			mutex_unlock(&slave->bus->bus_lock);
651 			if (dev_num < 0) {
652 				dev_err(bus->dev, "Get dev_num failed: %d\n",
653 					dev_num);
654 				return dev_num;
655 			}
656 			slave->dev_num = dev_num;
657 			slave->dev_num_sticky = dev_num;
658 			new_device = true;
659 		} else {
660 			slave->dev_num = slave->dev_num_sticky;
661 		}
662 	}
663 
664 	if (!new_device)
665 		dev_dbg(bus->dev,
666 			"Slave already registered, reusing dev_num:%d\n",
667 			slave->dev_num);
668 
669 	/* Clear the slave->dev_num to transfer message on device 0 */
670 	dev_num = slave->dev_num;
671 	slave->dev_num = 0;
672 
673 	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
674 	if (ret < 0) {
675 		dev_err(bus->dev, "Program device_num %d failed: %d\n",
676 			dev_num, ret);
677 		return ret;
678 	}
679 
680 	/* After xfer of msg, restore dev_num */
681 	slave->dev_num = slave->dev_num_sticky;
682 
683 	return 0;
684 }
685 
686 void sdw_extract_slave_id(struct sdw_bus *bus,
687 			  u64 addr, struct sdw_slave_id *id)
688 {
689 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
690 
691 	id->sdw_version = SDW_VERSION(addr);
692 	id->unique_id = SDW_UNIQUE_ID(addr);
693 	id->mfg_id = SDW_MFG_ID(addr);
694 	id->part_id = SDW_PART_ID(addr);
695 	id->class_id = SDW_CLASS_ID(addr);
696 
697 	dev_dbg(bus->dev,
698 		"SDW Slave class_id 0x%02x, mfg_id 0x%04x, part_id 0x%04x, unique_id 0x%x, version 0x%x\n",
699 		id->class_id, id->mfg_id, id->part_id, id->unique_id, id->sdw_version);
700 }
701 
702 static int sdw_program_device_num(struct sdw_bus *bus)
703 {
704 	u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
705 	struct sdw_slave *slave, *_s;
706 	struct sdw_slave_id id;
707 	struct sdw_msg msg;
708 	bool found = false;
709 	int count = 0, ret;
710 	u64 addr;
711 
712 	/* No Slave, so use raw xfer api */
713 	ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
714 			   SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
715 	if (ret < 0)
716 		return ret;
717 
718 	do {
719 		ret = sdw_transfer(bus, &msg);
720 		if (ret == -ENODATA) { /* end of device id reads */
721 			dev_dbg(bus->dev, "No more devices to enumerate\n");
722 			ret = 0;
723 			break;
724 		}
725 		if (ret < 0) {
726 			dev_err(bus->dev, "DEVID read fail:%d\n", ret);
727 			break;
728 		}
729 
730 		/*
731 		 * Construct the addr and extract. Cast the higher shift
732 		 * bits to avoid truncation due to size limit.
733 		 */
734 		addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
735 			((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
736 			((u64)buf[0] << 40);
737 
738 		sdw_extract_slave_id(bus, addr, &id);
739 
740 		/* Now compare with entries */
741 		list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
742 			if (sdw_compare_devid(slave, id) == 0) {
743 				found = true;
744 
745 				/*
746 				 * Assign a new dev_num to this Slave and
747 				 * not mark it present. It will be marked
748 				 * present after it reports ATTACHED on new
749 				 * dev_num
750 				 */
751 				ret = sdw_assign_device_num(slave);
752 				if (ret) {
753 					dev_err(bus->dev,
754 						"Assign dev_num failed:%d\n",
755 						ret);
756 					return ret;
757 				}
758 
759 				break;
760 			}
761 		}
762 
763 		if (!found) {
764 			/* TODO: Park this device in Group 13 */
765 
766 			/*
767 			 * add Slave device even if there is no platform
768 			 * firmware description. There will be no driver probe
769 			 * but the user/integration will be able to see the
770 			 * device, enumeration status and device number in sysfs
771 			 */
772 			sdw_slave_add(bus, &id, NULL);
773 
774 			dev_err(bus->dev, "Slave Entry not found\n");
775 		}
776 
777 		count++;
778 
779 		/*
780 		 * Check till error out or retry (count) exhausts.
781 		 * Device can drop off and rejoin during enumeration
782 		 * so count till twice the bound.
783 		 */
784 
785 	} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
786 
787 	return ret;
788 }
789 
790 static void sdw_modify_slave_status(struct sdw_slave *slave,
791 				    enum sdw_slave_status status)
792 {
793 	struct sdw_bus *bus = slave->bus;
794 
795 	mutex_lock(&bus->bus_lock);
796 
797 	dev_vdbg(bus->dev,
798 		 "%s: changing status slave %d status %d new status %d\n",
799 		 __func__, slave->dev_num, slave->status, status);
800 
801 	if (status == SDW_SLAVE_UNATTACHED) {
802 		dev_dbg(&slave->dev,
803 			"%s: initializing enumeration and init completion for Slave %d\n",
804 			__func__, slave->dev_num);
805 
806 		init_completion(&slave->enumeration_complete);
807 		init_completion(&slave->initialization_complete);
808 
809 	} else if ((status == SDW_SLAVE_ATTACHED) &&
810 		   (slave->status == SDW_SLAVE_UNATTACHED)) {
811 		dev_dbg(&slave->dev,
812 			"%s: signaling enumeration completion for Slave %d\n",
813 			__func__, slave->dev_num);
814 
815 		complete(&slave->enumeration_complete);
816 	}
817 	slave->status = status;
818 	mutex_unlock(&bus->bus_lock);
819 }
820 
821 static enum sdw_clk_stop_mode sdw_get_clk_stop_mode(struct sdw_slave *slave)
822 {
823 	enum sdw_clk_stop_mode mode;
824 
825 	/*
826 	 * Query for clock stop mode if Slave implements
827 	 * ops->get_clk_stop_mode, else read from property.
828 	 */
829 	if (slave->ops && slave->ops->get_clk_stop_mode) {
830 		mode = slave->ops->get_clk_stop_mode(slave);
831 	} else {
832 		if (slave->prop.clk_stop_mode1)
833 			mode = SDW_CLK_STOP_MODE1;
834 		else
835 			mode = SDW_CLK_STOP_MODE0;
836 	}
837 
838 	return mode;
839 }
840 
841 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
842 				       enum sdw_clk_stop_mode mode,
843 				       enum sdw_clk_stop_type type)
844 {
845 	int ret;
846 
847 	if (slave->ops && slave->ops->clk_stop) {
848 		ret = slave->ops->clk_stop(slave, mode, type);
849 		if (ret < 0) {
850 			dev_err(&slave->dev,
851 				"Clk Stop type =%d failed: %d\n", type, ret);
852 			return ret;
853 		}
854 	}
855 
856 	return 0;
857 }
858 
859 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
860 				      enum sdw_clk_stop_mode mode,
861 				      bool prepare)
862 {
863 	bool wake_en;
864 	u32 val = 0;
865 	int ret;
866 
867 	wake_en = slave->prop.wake_capable;
868 
869 	if (prepare) {
870 		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
871 
872 		if (mode == SDW_CLK_STOP_MODE1)
873 			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
874 
875 		if (wake_en)
876 			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
877 	} else {
878 		val = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
879 
880 		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
881 	}
882 
883 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
884 
885 	if (ret != 0)
886 		dev_err(&slave->dev,
887 			"Clock Stop prepare failed for slave: %d", ret);
888 
889 	return ret;
890 }
891 
892 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
893 {
894 	int retry = bus->clk_stop_timeout;
895 	int val;
896 
897 	do {
898 		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT) &
899 			SDW_SCP_STAT_CLK_STP_NF;
900 		if (!val) {
901 			dev_info(bus->dev, "clock stop prep/de-prep done slave:%d",
902 				 dev_num);
903 			return 0;
904 		}
905 
906 		usleep_range(1000, 1500);
907 		retry--;
908 	} while (retry);
909 
910 	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d",
911 		dev_num);
912 
913 	return -ETIMEDOUT;
914 }
915 
916 /**
917  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
918  *
919  * @bus: SDW bus instance
920  *
921  * Query Slave for clock stop mode and prepare for that mode.
922  */
923 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
924 {
925 	enum sdw_clk_stop_mode slave_mode;
926 	bool simple_clk_stop = true;
927 	struct sdw_slave *slave;
928 	bool is_slave = false;
929 	int ret = 0;
930 
931 	/*
932 	 * In order to save on transition time, prepare
933 	 * each Slave and then wait for all Slave(s) to be
934 	 * prepared for clock stop.
935 	 */
936 	list_for_each_entry(slave, &bus->slaves, node) {
937 		if (!slave->dev_num)
938 			continue;
939 
940 		if (slave->status != SDW_SLAVE_ATTACHED &&
941 		    slave->status != SDW_SLAVE_ALERT)
942 			continue;
943 
944 		/* Identify if Slave(s) are available on Bus */
945 		is_slave = true;
946 
947 		slave_mode = sdw_get_clk_stop_mode(slave);
948 		slave->curr_clk_stop_mode = slave_mode;
949 
950 		ret = sdw_slave_clk_stop_callback(slave, slave_mode,
951 						  SDW_CLK_PRE_PREPARE);
952 		if (ret < 0) {
953 			dev_err(&slave->dev,
954 				"pre-prepare failed:%d", ret);
955 			return ret;
956 		}
957 
958 		ret = sdw_slave_clk_stop_prepare(slave,
959 						 slave_mode, true);
960 		if (ret < 0) {
961 			dev_err(&slave->dev,
962 				"pre-prepare failed:%d", ret);
963 			return ret;
964 		}
965 
966 		if (slave_mode == SDW_CLK_STOP_MODE1)
967 			simple_clk_stop = false;
968 	}
969 
970 	/* Skip remaining clock stop preparation if no Slave is attached */
971 	if (!is_slave)
972 		return ret;
973 
974 	if (!simple_clk_stop) {
975 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
976 						       SDW_BROADCAST_DEV_NUM);
977 		if (ret < 0)
978 			return ret;
979 	}
980 
981 	/* Inform slaves that prep is done */
982 	list_for_each_entry(slave, &bus->slaves, node) {
983 		if (!slave->dev_num)
984 			continue;
985 
986 		if (slave->status != SDW_SLAVE_ATTACHED &&
987 		    slave->status != SDW_SLAVE_ALERT)
988 			continue;
989 
990 		slave_mode = slave->curr_clk_stop_mode;
991 
992 		if (slave_mode == SDW_CLK_STOP_MODE1) {
993 			ret = sdw_slave_clk_stop_callback(slave,
994 							  slave_mode,
995 							  SDW_CLK_POST_PREPARE);
996 
997 			if (ret < 0) {
998 				dev_err(&slave->dev,
999 					"post-prepare failed:%d", ret);
1000 			}
1001 		}
1002 	}
1003 
1004 	return ret;
1005 }
1006 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
1007 
1008 /**
1009  * sdw_bus_clk_stop: stop bus clock
1010  *
1011  * @bus: SDW bus instance
1012  *
1013  * After preparing the Slaves for clock stop, stop the clock by broadcasting
1014  * write to SCP_CTRL register.
1015  */
1016 int sdw_bus_clk_stop(struct sdw_bus *bus)
1017 {
1018 	int ret;
1019 
1020 	/*
1021 	 * broadcast clock stop now, attached Slaves will ACK this,
1022 	 * unattached will ignore
1023 	 */
1024 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1025 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1026 	if (ret < 0) {
1027 		if (ret == -ENODATA)
1028 			dev_dbg(bus->dev,
1029 				"ClockStopNow Broadcast msg ignored %d", ret);
1030 		else
1031 			dev_err(bus->dev,
1032 				"ClockStopNow Broadcast msg failed %d", ret);
1033 		return ret;
1034 	}
1035 
1036 	return 0;
1037 }
1038 EXPORT_SYMBOL(sdw_bus_clk_stop);
1039 
1040 /**
1041  * sdw_bus_exit_clk_stop: Exit clock stop mode
1042  *
1043  * @bus: SDW bus instance
1044  *
1045  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1046  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1047  * back.
1048  */
1049 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1050 {
1051 	enum sdw_clk_stop_mode mode;
1052 	bool simple_clk_stop = true;
1053 	struct sdw_slave *slave;
1054 	bool is_slave = false;
1055 	int ret;
1056 
1057 	/*
1058 	 * In order to save on transition time, de-prepare
1059 	 * each Slave and then wait for all Slave(s) to be
1060 	 * de-prepared after clock resume.
1061 	 */
1062 	list_for_each_entry(slave, &bus->slaves, node) {
1063 		if (!slave->dev_num)
1064 			continue;
1065 
1066 		if (slave->status != SDW_SLAVE_ATTACHED &&
1067 		    slave->status != SDW_SLAVE_ALERT)
1068 			continue;
1069 
1070 		/* Identify if Slave(s) are available on Bus */
1071 		is_slave = true;
1072 
1073 		mode = slave->curr_clk_stop_mode;
1074 
1075 		if (mode == SDW_CLK_STOP_MODE1) {
1076 			simple_clk_stop = false;
1077 			continue;
1078 		}
1079 
1080 		ret = sdw_slave_clk_stop_callback(slave, mode,
1081 						  SDW_CLK_PRE_DEPREPARE);
1082 		if (ret < 0)
1083 			dev_warn(&slave->dev,
1084 				 "clk stop deprep failed:%d", ret);
1085 
1086 		ret = sdw_slave_clk_stop_prepare(slave, mode,
1087 						 false);
1088 
1089 		if (ret < 0)
1090 			dev_warn(&slave->dev,
1091 				 "clk stop deprep failed:%d", ret);
1092 	}
1093 
1094 	/* Skip remaining clock stop de-preparation if no Slave is attached */
1095 	if (!is_slave)
1096 		return 0;
1097 
1098 	if (!simple_clk_stop)
1099 		sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1100 
1101 	list_for_each_entry(slave, &bus->slaves, node) {
1102 		if (!slave->dev_num)
1103 			continue;
1104 
1105 		if (slave->status != SDW_SLAVE_ATTACHED &&
1106 		    slave->status != SDW_SLAVE_ALERT)
1107 			continue;
1108 
1109 		mode = slave->curr_clk_stop_mode;
1110 		sdw_slave_clk_stop_callback(slave, mode,
1111 					    SDW_CLK_POST_DEPREPARE);
1112 	}
1113 
1114 	return 0;
1115 }
1116 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1117 
1118 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1119 			   int port, bool enable, int mask)
1120 {
1121 	u32 addr;
1122 	int ret;
1123 	u8 val = 0;
1124 
1125 	if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1126 		dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1127 			enable ? "on" : "off");
1128 		mask |= SDW_DPN_INT_TEST_FAIL;
1129 	}
1130 
1131 	addr = SDW_DPN_INTMASK(port);
1132 
1133 	/* Set/Clear port ready interrupt mask */
1134 	if (enable) {
1135 		val |= mask;
1136 		val |= SDW_DPN_INT_PORT_READY;
1137 	} else {
1138 		val &= ~(mask);
1139 		val &= ~SDW_DPN_INT_PORT_READY;
1140 	}
1141 
1142 	ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1143 	if (ret < 0)
1144 		dev_err(&slave->dev,
1145 			"SDW_DPN_INTMASK write failed:%d\n", val);
1146 
1147 	return ret;
1148 }
1149 
1150 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1151 {
1152 	u32 mclk_freq = slave->bus->prop.mclk_freq;
1153 	u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1154 	unsigned int scale;
1155 	u8 scale_index;
1156 	u8 base;
1157 	int ret;
1158 
1159 	/*
1160 	 * frequency base and scale registers are required for SDCA
1161 	 * devices. They may also be used for 1.2+/non-SDCA devices,
1162 	 * but we will need a DisCo property to cover this case
1163 	 */
1164 	if (!slave->id.class_id)
1165 		return 0;
1166 
1167 	if (!mclk_freq) {
1168 		dev_err(&slave->dev,
1169 			"no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1170 		return -EINVAL;
1171 	}
1172 
1173 	/*
1174 	 * map base frequency using Table 89 of SoundWire 1.2 spec.
1175 	 * The order of the tests just follows the specification, this
1176 	 * is not a selection between possible values or a search for
1177 	 * the best value but just a mapping.  Only one case per platform
1178 	 * is relevant.
1179 	 * Some BIOS have inconsistent values for mclk_freq but a
1180 	 * correct root so we force the mclk_freq to avoid variations.
1181 	 */
1182 	if (!(19200000 % mclk_freq)) {
1183 		mclk_freq = 19200000;
1184 		base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1185 	} else if (!(24000000 % mclk_freq)) {
1186 		mclk_freq = 24000000;
1187 		base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1188 	} else if (!(24576000 % mclk_freq)) {
1189 		mclk_freq = 24576000;
1190 		base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1191 	} else if (!(22579200 % mclk_freq)) {
1192 		mclk_freq = 22579200;
1193 		base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1194 	} else if (!(32000000 % mclk_freq)) {
1195 		mclk_freq = 32000000;
1196 		base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1197 	} else {
1198 		dev_err(&slave->dev,
1199 			"Unsupported clock base, mclk %d\n",
1200 			mclk_freq);
1201 		return -EINVAL;
1202 	}
1203 
1204 	if (mclk_freq % curr_freq) {
1205 		dev_err(&slave->dev,
1206 			"mclk %d is not multiple of bus curr_freq %d\n",
1207 			mclk_freq, curr_freq);
1208 		return -EINVAL;
1209 	}
1210 
1211 	scale = mclk_freq / curr_freq;
1212 
1213 	/*
1214 	 * map scale to Table 90 of SoundWire 1.2 spec - and check
1215 	 * that the scale is a power of two and maximum 64
1216 	 */
1217 	scale_index = ilog2(scale);
1218 
1219 	if (BIT(scale_index) != scale || scale_index > 6) {
1220 		dev_err(&slave->dev,
1221 			"No match found for scale %d, bus mclk %d curr_freq %d\n",
1222 			scale, mclk_freq, curr_freq);
1223 		return -EINVAL;
1224 	}
1225 	scale_index++;
1226 
1227 	ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1228 	if (ret < 0) {
1229 		dev_err(&slave->dev,
1230 			"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1231 		return ret;
1232 	}
1233 
1234 	/* initialize scale for both banks */
1235 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1236 	if (ret < 0) {
1237 		dev_err(&slave->dev,
1238 			"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1239 		return ret;
1240 	}
1241 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1242 	if (ret < 0)
1243 		dev_err(&slave->dev,
1244 			"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1245 
1246 	dev_dbg(&slave->dev,
1247 		"Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1248 		base, scale_index, mclk_freq, curr_freq);
1249 
1250 	return ret;
1251 }
1252 
1253 static int sdw_initialize_slave(struct sdw_slave *slave)
1254 {
1255 	struct sdw_slave_prop *prop = &slave->prop;
1256 	int ret;
1257 	u8 val;
1258 
1259 	ret = sdw_slave_set_frequency(slave);
1260 	if (ret < 0)
1261 		return ret;
1262 
1263 	/*
1264 	 * Set SCP_INT1_MASK register, typically bus clash and
1265 	 * implementation-defined interrupt mask. The Parity detection
1266 	 * may not always be correct on startup so its use is
1267 	 * device-dependent, it might e.g. only be enabled in
1268 	 * steady-state after a couple of frames.
1269 	 */
1270 	val = slave->prop.scp_int1_mask;
1271 
1272 	/* Enable SCP interrupts */
1273 	ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
1274 	if (ret < 0) {
1275 		dev_err(&slave->dev,
1276 			"SDW_SCP_INTMASK1 write failed:%d\n", ret);
1277 		return ret;
1278 	}
1279 
1280 	/* No need to continue if DP0 is not present */
1281 	if (!slave->prop.dp0_prop)
1282 		return 0;
1283 
1284 	/* Enable DP0 interrupts */
1285 	val = prop->dp0_prop->imp_def_interrupts;
1286 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1287 
1288 	ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
1289 	if (ret < 0)
1290 		dev_err(&slave->dev,
1291 			"SDW_DP0_INTMASK read failed:%d\n", ret);
1292 	return ret;
1293 }
1294 
1295 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1296 {
1297 	u8 clear, impl_int_mask;
1298 	int status, status2, ret, count = 0;
1299 
1300 	status = sdw_read_no_pm(slave, SDW_DP0_INT);
1301 	if (status < 0) {
1302 		dev_err(&slave->dev,
1303 			"SDW_DP0_INT read failed:%d\n", status);
1304 		return status;
1305 	}
1306 
1307 	do {
1308 		clear = status & ~SDW_DP0_INTERRUPTS;
1309 
1310 		if (status & SDW_DP0_INT_TEST_FAIL) {
1311 			dev_err(&slave->dev, "Test fail for port 0\n");
1312 			clear |= SDW_DP0_INT_TEST_FAIL;
1313 		}
1314 
1315 		/*
1316 		 * Assumption: PORT_READY interrupt will be received only for
1317 		 * ports implementing Channel Prepare state machine (CP_SM)
1318 		 */
1319 
1320 		if (status & SDW_DP0_INT_PORT_READY) {
1321 			complete(&slave->port_ready[0]);
1322 			clear |= SDW_DP0_INT_PORT_READY;
1323 		}
1324 
1325 		if (status & SDW_DP0_INT_BRA_FAILURE) {
1326 			dev_err(&slave->dev, "BRA failed\n");
1327 			clear |= SDW_DP0_INT_BRA_FAILURE;
1328 		}
1329 
1330 		impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1331 			SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1332 
1333 		if (status & impl_int_mask) {
1334 			clear |= impl_int_mask;
1335 			*slave_status = clear;
1336 		}
1337 
1338 		/* clear the interrupts but don't touch reserved and SDCA_CASCADE fields */
1339 		ret = sdw_write_no_pm(slave, SDW_DP0_INT, clear);
1340 		if (ret < 0) {
1341 			dev_err(&slave->dev,
1342 				"SDW_DP0_INT write failed:%d\n", ret);
1343 			return ret;
1344 		}
1345 
1346 		/* Read DP0 interrupt again */
1347 		status2 = sdw_read_no_pm(slave, SDW_DP0_INT);
1348 		if (status2 < 0) {
1349 			dev_err(&slave->dev,
1350 				"SDW_DP0_INT read failed:%d\n", status2);
1351 			return status2;
1352 		}
1353 		/* filter to limit loop to interrupts identified in the first status read */
1354 		status &= status2;
1355 
1356 		count++;
1357 
1358 		/* we can get alerts while processing so keep retrying */
1359 	} while ((status & SDW_DP0_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1360 
1361 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1362 		dev_warn(&slave->dev, "Reached MAX_RETRY on DP0 read\n");
1363 
1364 	return ret;
1365 }
1366 
1367 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1368 				     int port, u8 *slave_status)
1369 {
1370 	u8 clear, impl_int_mask;
1371 	int status, status2, ret, count = 0;
1372 	u32 addr;
1373 
1374 	if (port == 0)
1375 		return sdw_handle_dp0_interrupt(slave, slave_status);
1376 
1377 	addr = SDW_DPN_INT(port);
1378 	status = sdw_read_no_pm(slave, addr);
1379 	if (status < 0) {
1380 		dev_err(&slave->dev,
1381 			"SDW_DPN_INT read failed:%d\n", status);
1382 
1383 		return status;
1384 	}
1385 
1386 	do {
1387 		clear = status & ~SDW_DPN_INTERRUPTS;
1388 
1389 		if (status & SDW_DPN_INT_TEST_FAIL) {
1390 			dev_err(&slave->dev, "Test fail for port:%d\n", port);
1391 			clear |= SDW_DPN_INT_TEST_FAIL;
1392 		}
1393 
1394 		/*
1395 		 * Assumption: PORT_READY interrupt will be received only
1396 		 * for ports implementing CP_SM.
1397 		 */
1398 		if (status & SDW_DPN_INT_PORT_READY) {
1399 			complete(&slave->port_ready[port]);
1400 			clear |= SDW_DPN_INT_PORT_READY;
1401 		}
1402 
1403 		impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1404 			SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1405 
1406 		if (status & impl_int_mask) {
1407 			clear |= impl_int_mask;
1408 			*slave_status = clear;
1409 		}
1410 
1411 		/* clear the interrupt but don't touch reserved fields */
1412 		ret = sdw_write_no_pm(slave, addr, clear);
1413 		if (ret < 0) {
1414 			dev_err(&slave->dev,
1415 				"SDW_DPN_INT write failed:%d\n", ret);
1416 			return ret;
1417 		}
1418 
1419 		/* Read DPN interrupt again */
1420 		status2 = sdw_read_no_pm(slave, addr);
1421 		if (status2 < 0) {
1422 			dev_err(&slave->dev,
1423 				"SDW_DPN_INT read failed:%d\n", status2);
1424 			return status2;
1425 		}
1426 		/* filter to limit loop to interrupts identified in the first status read */
1427 		status &= status2;
1428 
1429 		count++;
1430 
1431 		/* we can get alerts while processing so keep retrying */
1432 	} while ((status & SDW_DPN_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1433 
1434 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1435 		dev_warn(&slave->dev, "Reached MAX_RETRY on port read");
1436 
1437 	return ret;
1438 }
1439 
1440 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1441 {
1442 	struct sdw_slave_intr_status slave_intr;
1443 	u8 clear = 0, bit, port_status[15] = {0};
1444 	int port_num, stat, ret, count = 0;
1445 	unsigned long port;
1446 	bool slave_notify;
1447 	u8 sdca_cascade = 0;
1448 	u8 buf, buf2[2], _buf, _buf2[2];
1449 	bool parity_check;
1450 	bool parity_quirk;
1451 
1452 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1453 
1454 	ret = pm_runtime_get_sync(&slave->dev);
1455 	if (ret < 0 && ret != -EACCES) {
1456 		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
1457 		pm_runtime_put_noidle(&slave->dev);
1458 		return ret;
1459 	}
1460 
1461 	/* Read Intstat 1, Intstat 2 and Intstat 3 registers */
1462 	ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1463 	if (ret < 0) {
1464 		dev_err(&slave->dev,
1465 			"SDW_SCP_INT1 read failed:%d\n", ret);
1466 		goto io_err;
1467 	}
1468 	buf = ret;
1469 
1470 	ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, buf2);
1471 	if (ret < 0) {
1472 		dev_err(&slave->dev,
1473 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
1474 		goto io_err;
1475 	}
1476 
1477 	if (slave->prop.is_sdca) {
1478 		ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1479 		if (ret < 0) {
1480 			dev_err(&slave->dev,
1481 				"SDW_DP0_INT read failed:%d\n", ret);
1482 			goto io_err;
1483 		}
1484 		sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1485 	}
1486 
1487 	do {
1488 		slave_notify = false;
1489 
1490 		/*
1491 		 * Check parity, bus clash and Slave (impl defined)
1492 		 * interrupt
1493 		 */
1494 		if (buf & SDW_SCP_INT1_PARITY) {
1495 			parity_check = slave->prop.scp_int1_mask & SDW_SCP_INT1_PARITY;
1496 			parity_quirk = !slave->first_interrupt_done &&
1497 				(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY);
1498 
1499 			if (parity_check && !parity_quirk)
1500 				dev_err(&slave->dev, "Parity error detected\n");
1501 			clear |= SDW_SCP_INT1_PARITY;
1502 		}
1503 
1504 		if (buf & SDW_SCP_INT1_BUS_CLASH) {
1505 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_BUS_CLASH)
1506 				dev_err(&slave->dev, "Bus clash detected\n");
1507 			clear |= SDW_SCP_INT1_BUS_CLASH;
1508 		}
1509 
1510 		/*
1511 		 * When bus clash or parity errors are detected, such errors
1512 		 * are unlikely to be recoverable errors.
1513 		 * TODO: In such scenario, reset bus. Make this configurable
1514 		 * via sysfs property with bus reset being the default.
1515 		 */
1516 
1517 		if (buf & SDW_SCP_INT1_IMPL_DEF) {
1518 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_IMPL_DEF) {
1519 				dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
1520 				slave_notify = true;
1521 			}
1522 			clear |= SDW_SCP_INT1_IMPL_DEF;
1523 		}
1524 
1525 		/* the SDCA interrupts are cleared in the codec driver .interrupt_callback() */
1526 		if (sdca_cascade)
1527 			slave_notify = true;
1528 
1529 		/* Check port 0 - 3 interrupts */
1530 		port = buf & SDW_SCP_INT1_PORT0_3;
1531 
1532 		/* To get port number corresponding to bits, shift it */
1533 		port = FIELD_GET(SDW_SCP_INT1_PORT0_3, port);
1534 		for_each_set_bit(bit, &port, 8) {
1535 			sdw_handle_port_interrupt(slave, bit,
1536 						  &port_status[bit]);
1537 		}
1538 
1539 		/* Check if cascade 2 interrupt is present */
1540 		if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
1541 			port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
1542 			for_each_set_bit(bit, &port, 8) {
1543 				/* scp2 ports start from 4 */
1544 				port_num = bit + 3;
1545 				sdw_handle_port_interrupt(slave,
1546 						port_num,
1547 						&port_status[port_num]);
1548 			}
1549 		}
1550 
1551 		/* now check last cascade */
1552 		if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
1553 			port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
1554 			for_each_set_bit(bit, &port, 8) {
1555 				/* scp3 ports start from 11 */
1556 				port_num = bit + 10;
1557 				sdw_handle_port_interrupt(slave,
1558 						port_num,
1559 						&port_status[port_num]);
1560 			}
1561 		}
1562 
1563 		/* Update the Slave driver */
1564 		if (slave_notify && slave->ops &&
1565 		    slave->ops->interrupt_callback) {
1566 			slave_intr.sdca_cascade = sdca_cascade;
1567 			slave_intr.control_port = clear;
1568 			memcpy(slave_intr.port, &port_status,
1569 			       sizeof(slave_intr.port));
1570 
1571 			slave->ops->interrupt_callback(slave, &slave_intr);
1572 		}
1573 
1574 		/* Ack interrupt */
1575 		ret = sdw_write_no_pm(slave, SDW_SCP_INT1, clear);
1576 		if (ret < 0) {
1577 			dev_err(&slave->dev,
1578 				"SDW_SCP_INT1 write failed:%d\n", ret);
1579 			goto io_err;
1580 		}
1581 
1582 		/* at this point all initial interrupt sources were handled */
1583 		slave->first_interrupt_done = true;
1584 
1585 		/*
1586 		 * Read status again to ensure no new interrupts arrived
1587 		 * while servicing interrupts.
1588 		 */
1589 		ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1590 		if (ret < 0) {
1591 			dev_err(&slave->dev,
1592 				"SDW_SCP_INT1 read failed:%d\n", ret);
1593 			goto io_err;
1594 		}
1595 		_buf = ret;
1596 
1597 		ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, _buf2);
1598 		if (ret < 0) {
1599 			dev_err(&slave->dev,
1600 				"SDW_SCP_INT2/3 read failed:%d\n", ret);
1601 			goto io_err;
1602 		}
1603 
1604 		if (slave->prop.is_sdca) {
1605 			ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1606 			if (ret < 0) {
1607 				dev_err(&slave->dev,
1608 					"SDW_DP0_INT read failed:%d\n", ret);
1609 				goto io_err;
1610 			}
1611 			sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1612 		}
1613 
1614 		/*
1615 		 * Make sure no interrupts are pending, but filter to limit loop
1616 		 * to interrupts identified in the first status read
1617 		 */
1618 		buf &= _buf;
1619 		buf2[0] &= _buf2[0];
1620 		buf2[1] &= _buf2[1];
1621 		stat = buf || buf2[0] || buf2[1] || sdca_cascade;
1622 
1623 		/*
1624 		 * Exit loop if Slave is continuously in ALERT state even
1625 		 * after servicing the interrupt multiple times.
1626 		 */
1627 		count++;
1628 
1629 		/* we can get alerts while processing so keep retrying */
1630 	} while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1631 
1632 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1633 		dev_warn(&slave->dev, "Reached MAX_RETRY on alert read\n");
1634 
1635 io_err:
1636 	pm_runtime_mark_last_busy(&slave->dev);
1637 	pm_runtime_put_autosuspend(&slave->dev);
1638 
1639 	return ret;
1640 }
1641 
1642 static int sdw_update_slave_status(struct sdw_slave *slave,
1643 				   enum sdw_slave_status status)
1644 {
1645 	unsigned long time;
1646 
1647 	if (!slave->probed) {
1648 		/*
1649 		 * the slave status update is typically handled in an
1650 		 * interrupt thread, which can race with the driver
1651 		 * probe, e.g. when a module needs to be loaded.
1652 		 *
1653 		 * make sure the probe is complete before updating
1654 		 * status.
1655 		 */
1656 		time = wait_for_completion_timeout(&slave->probe_complete,
1657 				msecs_to_jiffies(DEFAULT_PROBE_TIMEOUT));
1658 		if (!time) {
1659 			dev_err(&slave->dev, "Probe not complete, timed out\n");
1660 			return -ETIMEDOUT;
1661 		}
1662 	}
1663 
1664 	if (!slave->ops || !slave->ops->update_status)
1665 		return 0;
1666 
1667 	return slave->ops->update_status(slave, status);
1668 }
1669 
1670 /**
1671  * sdw_handle_slave_status() - Handle Slave status
1672  * @bus: SDW bus instance
1673  * @status: Status for all Slave(s)
1674  */
1675 int sdw_handle_slave_status(struct sdw_bus *bus,
1676 			    enum sdw_slave_status status[])
1677 {
1678 	enum sdw_slave_status prev_status;
1679 	struct sdw_slave *slave;
1680 	bool attached_initializing;
1681 	int i, ret = 0;
1682 
1683 	/* first check if any Slaves fell off the bus */
1684 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1685 		mutex_lock(&bus->bus_lock);
1686 		if (test_bit(i, bus->assigned) == false) {
1687 			mutex_unlock(&bus->bus_lock);
1688 			continue;
1689 		}
1690 		mutex_unlock(&bus->bus_lock);
1691 
1692 		slave = sdw_get_slave(bus, i);
1693 		if (!slave)
1694 			continue;
1695 
1696 		if (status[i] == SDW_SLAVE_UNATTACHED &&
1697 		    slave->status != SDW_SLAVE_UNATTACHED)
1698 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1699 	}
1700 
1701 	if (status[0] == SDW_SLAVE_ATTACHED) {
1702 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
1703 		ret = sdw_program_device_num(bus);
1704 		if (ret)
1705 			dev_err(bus->dev, "Slave attach failed: %d\n", ret);
1706 		/*
1707 		 * programming a device number will have side effects,
1708 		 * so we deal with other devices at a later time
1709 		 */
1710 		return ret;
1711 	}
1712 
1713 	/* Continue to check other slave statuses */
1714 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1715 		mutex_lock(&bus->bus_lock);
1716 		if (test_bit(i, bus->assigned) == false) {
1717 			mutex_unlock(&bus->bus_lock);
1718 			continue;
1719 		}
1720 		mutex_unlock(&bus->bus_lock);
1721 
1722 		slave = sdw_get_slave(bus, i);
1723 		if (!slave)
1724 			continue;
1725 
1726 		attached_initializing = false;
1727 
1728 		switch (status[i]) {
1729 		case SDW_SLAVE_UNATTACHED:
1730 			if (slave->status == SDW_SLAVE_UNATTACHED)
1731 				break;
1732 
1733 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1734 			break;
1735 
1736 		case SDW_SLAVE_ALERT:
1737 			ret = sdw_handle_slave_alerts(slave);
1738 			if (ret)
1739 				dev_err(&slave->dev,
1740 					"Slave %d alert handling failed: %d\n",
1741 					i, ret);
1742 			break;
1743 
1744 		case SDW_SLAVE_ATTACHED:
1745 			if (slave->status == SDW_SLAVE_ATTACHED)
1746 				break;
1747 
1748 			prev_status = slave->status;
1749 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1750 
1751 			if (prev_status == SDW_SLAVE_ALERT)
1752 				break;
1753 
1754 			attached_initializing = true;
1755 
1756 			ret = sdw_initialize_slave(slave);
1757 			if (ret)
1758 				dev_err(&slave->dev,
1759 					"Slave %d initialization failed: %d\n",
1760 					i, ret);
1761 
1762 			break;
1763 
1764 		default:
1765 			dev_err(&slave->dev, "Invalid slave %d status:%d\n",
1766 				i, status[i]);
1767 			break;
1768 		}
1769 
1770 		ret = sdw_update_slave_status(slave, status[i]);
1771 		if (ret)
1772 			dev_err(&slave->dev,
1773 				"Update Slave status failed:%d\n", ret);
1774 		if (attached_initializing) {
1775 			dev_dbg(&slave->dev,
1776 				"%s: signaling initialization completion for Slave %d\n",
1777 				__func__, slave->dev_num);
1778 
1779 			complete(&slave->initialization_complete);
1780 		}
1781 	}
1782 
1783 	return ret;
1784 }
1785 EXPORT_SYMBOL(sdw_handle_slave_status);
1786 
1787 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1788 {
1789 	struct sdw_slave *slave;
1790 	int i;
1791 
1792 	/* Check all non-zero devices */
1793 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1794 		mutex_lock(&bus->bus_lock);
1795 		if (test_bit(i, bus->assigned) == false) {
1796 			mutex_unlock(&bus->bus_lock);
1797 			continue;
1798 		}
1799 		mutex_unlock(&bus->bus_lock);
1800 
1801 		slave = sdw_get_slave(bus, i);
1802 		if (!slave)
1803 			continue;
1804 
1805 		if (slave->status != SDW_SLAVE_UNATTACHED) {
1806 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1807 			slave->first_interrupt_done = false;
1808 		}
1809 
1810 		/* keep track of request, used in pm_runtime resume */
1811 		slave->unattach_request = request;
1812 	}
1813 }
1814 EXPORT_SYMBOL(sdw_clear_slave_status);
1815