xref: /linux/drivers/soundwire/bus.c (revision 5860800e8696d2cbbd1a0dd60b433549d176e668)
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 	ret = sdw_transfer(slave->bus, &msg);
394 	if (slave->is_mockup_device)
395 		ret = 0;
396 	return ret;
397 }
398 
399 static int
400 sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
401 {
402 	struct sdw_msg msg;
403 	int ret;
404 
405 	ret = sdw_fill_msg(&msg, slave, addr, count,
406 			   slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val);
407 	if (ret < 0)
408 		return ret;
409 
410 	ret = sdw_transfer(slave->bus, &msg);
411 	if (slave->is_mockup_device)
412 		ret = 0;
413 	return ret;
414 }
415 
416 int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
417 {
418 	return sdw_nwrite_no_pm(slave, addr, 1, &value);
419 }
420 EXPORT_SYMBOL(sdw_write_no_pm);
421 
422 static int
423 sdw_bread_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr)
424 {
425 	struct sdw_msg msg;
426 	u8 buf;
427 	int ret;
428 
429 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
430 			   SDW_MSG_FLAG_READ, &buf);
431 	if (ret < 0)
432 		return ret;
433 
434 	ret = sdw_transfer(bus, &msg);
435 	if (ret < 0)
436 		return ret;
437 
438 	return buf;
439 }
440 
441 static int
442 sdw_bwrite_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
443 {
444 	struct sdw_msg msg;
445 	int ret;
446 
447 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
448 			   SDW_MSG_FLAG_WRITE, &value);
449 	if (ret < 0)
450 		return ret;
451 
452 	return sdw_transfer(bus, &msg);
453 }
454 
455 int sdw_bread_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr)
456 {
457 	struct sdw_msg msg;
458 	u8 buf;
459 	int ret;
460 
461 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
462 			   SDW_MSG_FLAG_READ, &buf);
463 	if (ret < 0)
464 		return ret;
465 
466 	ret = sdw_transfer_unlocked(bus, &msg);
467 	if (ret < 0)
468 		return ret;
469 
470 	return buf;
471 }
472 EXPORT_SYMBOL(sdw_bread_no_pm_unlocked);
473 
474 int sdw_bwrite_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
475 {
476 	struct sdw_msg msg;
477 	int ret;
478 
479 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
480 			   SDW_MSG_FLAG_WRITE, &value);
481 	if (ret < 0)
482 		return ret;
483 
484 	return sdw_transfer_unlocked(bus, &msg);
485 }
486 EXPORT_SYMBOL(sdw_bwrite_no_pm_unlocked);
487 
488 int sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
489 {
490 	u8 buf;
491 	int ret;
492 
493 	ret = sdw_nread_no_pm(slave, addr, 1, &buf);
494 	if (ret < 0)
495 		return ret;
496 	else
497 		return buf;
498 }
499 EXPORT_SYMBOL(sdw_read_no_pm);
500 
501 int sdw_update_no_pm(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
502 {
503 	int tmp;
504 
505 	tmp = sdw_read_no_pm(slave, addr);
506 	if (tmp < 0)
507 		return tmp;
508 
509 	tmp = (tmp & ~mask) | val;
510 	return sdw_write_no_pm(slave, addr, tmp);
511 }
512 EXPORT_SYMBOL(sdw_update_no_pm);
513 
514 /* Read-Modify-Write Slave register */
515 int sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
516 {
517 	int tmp;
518 
519 	tmp = sdw_read(slave, addr);
520 	if (tmp < 0)
521 		return tmp;
522 
523 	tmp = (tmp & ~mask) | val;
524 	return sdw_write(slave, addr, tmp);
525 }
526 EXPORT_SYMBOL(sdw_update);
527 
528 /**
529  * sdw_nread() - Read "n" contiguous SDW Slave registers
530  * @slave: SDW Slave
531  * @addr: Register address
532  * @count: length
533  * @val: Buffer for values to be read
534  */
535 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
536 {
537 	int ret;
538 
539 	ret = pm_runtime_resume_and_get(&slave->dev);
540 	if (ret < 0 && ret != -EACCES)
541 		return ret;
542 
543 	ret = sdw_nread_no_pm(slave, addr, count, val);
544 
545 	pm_runtime_mark_last_busy(&slave->dev);
546 	pm_runtime_put(&slave->dev);
547 
548 	return ret;
549 }
550 EXPORT_SYMBOL(sdw_nread);
551 
552 /**
553  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
554  * @slave: SDW Slave
555  * @addr: Register address
556  * @count: length
557  * @val: Buffer for values to be written
558  */
559 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
560 {
561 	int ret;
562 
563 	ret = pm_runtime_resume_and_get(&slave->dev);
564 	if (ret < 0 && ret != -EACCES)
565 		return ret;
566 
567 	ret = sdw_nwrite_no_pm(slave, addr, count, val);
568 
569 	pm_runtime_mark_last_busy(&slave->dev);
570 	pm_runtime_put(&slave->dev);
571 
572 	return ret;
573 }
574 EXPORT_SYMBOL(sdw_nwrite);
575 
576 /**
577  * sdw_read() - Read a SDW Slave register
578  * @slave: SDW Slave
579  * @addr: Register address
580  */
581 int sdw_read(struct sdw_slave *slave, u32 addr)
582 {
583 	u8 buf;
584 	int ret;
585 
586 	ret = sdw_nread(slave, addr, 1, &buf);
587 	if (ret < 0)
588 		return ret;
589 
590 	return buf;
591 }
592 EXPORT_SYMBOL(sdw_read);
593 
594 /**
595  * sdw_write() - Write a SDW Slave register
596  * @slave: SDW Slave
597  * @addr: Register address
598  * @value: Register value
599  */
600 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
601 {
602 	return sdw_nwrite(slave, addr, 1, &value);
603 }
604 EXPORT_SYMBOL(sdw_write);
605 
606 /*
607  * SDW alert handling
608  */
609 
610 /* called with bus_lock held */
611 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
612 {
613 	struct sdw_slave *slave;
614 
615 	list_for_each_entry(slave, &bus->slaves, node) {
616 		if (slave->dev_num == i)
617 			return slave;
618 	}
619 
620 	return NULL;
621 }
622 
623 int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
624 {
625 	if (slave->id.mfg_id != id.mfg_id ||
626 	    slave->id.part_id != id.part_id ||
627 	    slave->id.class_id != id.class_id ||
628 	    (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
629 	     slave->id.unique_id != id.unique_id))
630 		return -ENODEV;
631 
632 	return 0;
633 }
634 EXPORT_SYMBOL(sdw_compare_devid);
635 
636 /* called with bus_lock held */
637 static int sdw_get_device_num(struct sdw_slave *slave)
638 {
639 	int bit;
640 
641 	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
642 	if (bit == SDW_MAX_DEVICES) {
643 		bit = -ENODEV;
644 		goto err;
645 	}
646 
647 	/*
648 	 * Do not update dev_num in Slave data structure here,
649 	 * Update once program dev_num is successful
650 	 */
651 	set_bit(bit, slave->bus->assigned);
652 
653 err:
654 	return bit;
655 }
656 
657 static int sdw_assign_device_num(struct sdw_slave *slave)
658 {
659 	struct sdw_bus *bus = slave->bus;
660 	int ret, dev_num;
661 	bool new_device = false;
662 
663 	/* check first if device number is assigned, if so reuse that */
664 	if (!slave->dev_num) {
665 		if (!slave->dev_num_sticky) {
666 			mutex_lock(&slave->bus->bus_lock);
667 			dev_num = sdw_get_device_num(slave);
668 			mutex_unlock(&slave->bus->bus_lock);
669 			if (dev_num < 0) {
670 				dev_err(bus->dev, "Get dev_num failed: %d\n",
671 					dev_num);
672 				return dev_num;
673 			}
674 			slave->dev_num = dev_num;
675 			slave->dev_num_sticky = dev_num;
676 			new_device = true;
677 		} else {
678 			slave->dev_num = slave->dev_num_sticky;
679 		}
680 	}
681 
682 	if (!new_device)
683 		dev_dbg(bus->dev,
684 			"Slave already registered, reusing dev_num:%d\n",
685 			slave->dev_num);
686 
687 	/* Clear the slave->dev_num to transfer message on device 0 */
688 	dev_num = slave->dev_num;
689 	slave->dev_num = 0;
690 
691 	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
692 	if (ret < 0) {
693 		dev_err(bus->dev, "Program device_num %d failed: %d\n",
694 			dev_num, ret);
695 		return ret;
696 	}
697 
698 	/* After xfer of msg, restore dev_num */
699 	slave->dev_num = slave->dev_num_sticky;
700 
701 	return 0;
702 }
703 
704 void sdw_extract_slave_id(struct sdw_bus *bus,
705 			  u64 addr, struct sdw_slave_id *id)
706 {
707 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
708 
709 	id->sdw_version = SDW_VERSION(addr);
710 	id->unique_id = SDW_UNIQUE_ID(addr);
711 	id->mfg_id = SDW_MFG_ID(addr);
712 	id->part_id = SDW_PART_ID(addr);
713 	id->class_id = SDW_CLASS_ID(addr);
714 
715 	dev_dbg(bus->dev,
716 		"SDW Slave class_id 0x%02x, mfg_id 0x%04x, part_id 0x%04x, unique_id 0x%x, version 0x%x\n",
717 		id->class_id, id->mfg_id, id->part_id, id->unique_id, id->sdw_version);
718 }
719 EXPORT_SYMBOL(sdw_extract_slave_id);
720 
721 static int sdw_program_device_num(struct sdw_bus *bus)
722 {
723 	u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
724 	struct sdw_slave *slave, *_s;
725 	struct sdw_slave_id id;
726 	struct sdw_msg msg;
727 	bool found;
728 	int count = 0, ret;
729 	u64 addr;
730 
731 	/* No Slave, so use raw xfer api */
732 	ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
733 			   SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
734 	if (ret < 0)
735 		return ret;
736 
737 	do {
738 		ret = sdw_transfer(bus, &msg);
739 		if (ret == -ENODATA) { /* end of device id reads */
740 			dev_dbg(bus->dev, "No more devices to enumerate\n");
741 			ret = 0;
742 			break;
743 		}
744 		if (ret < 0) {
745 			dev_err(bus->dev, "DEVID read fail:%d\n", ret);
746 			break;
747 		}
748 
749 		/*
750 		 * Construct the addr and extract. Cast the higher shift
751 		 * bits to avoid truncation due to size limit.
752 		 */
753 		addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
754 			((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
755 			((u64)buf[0] << 40);
756 
757 		sdw_extract_slave_id(bus, addr, &id);
758 
759 		found = false;
760 		/* Now compare with entries */
761 		list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
762 			if (sdw_compare_devid(slave, id) == 0) {
763 				found = true;
764 
765 				/*
766 				 * Assign a new dev_num to this Slave and
767 				 * not mark it present. It will be marked
768 				 * present after it reports ATTACHED on new
769 				 * dev_num
770 				 */
771 				ret = sdw_assign_device_num(slave);
772 				if (ret < 0) {
773 					dev_err(bus->dev,
774 						"Assign dev_num failed:%d\n",
775 						ret);
776 					return ret;
777 				}
778 
779 				break;
780 			}
781 		}
782 
783 		if (!found) {
784 			/* TODO: Park this device in Group 13 */
785 
786 			/*
787 			 * add Slave device even if there is no platform
788 			 * firmware description. There will be no driver probe
789 			 * but the user/integration will be able to see the
790 			 * device, enumeration status and device number in sysfs
791 			 */
792 			sdw_slave_add(bus, &id, NULL);
793 
794 			dev_err(bus->dev, "Slave Entry not found\n");
795 		}
796 
797 		count++;
798 
799 		/*
800 		 * Check till error out or retry (count) exhausts.
801 		 * Device can drop off and rejoin during enumeration
802 		 * so count till twice the bound.
803 		 */
804 
805 	} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
806 
807 	return ret;
808 }
809 
810 static void sdw_modify_slave_status(struct sdw_slave *slave,
811 				    enum sdw_slave_status status)
812 {
813 	struct sdw_bus *bus = slave->bus;
814 
815 	mutex_lock(&bus->bus_lock);
816 
817 	dev_vdbg(bus->dev,
818 		 "%s: changing status slave %d status %d new status %d\n",
819 		 __func__, slave->dev_num, slave->status, status);
820 
821 	if (status == SDW_SLAVE_UNATTACHED) {
822 		dev_dbg(&slave->dev,
823 			"%s: initializing enumeration and init completion for Slave %d\n",
824 			__func__, slave->dev_num);
825 
826 		init_completion(&slave->enumeration_complete);
827 		init_completion(&slave->initialization_complete);
828 
829 	} else if ((status == SDW_SLAVE_ATTACHED) &&
830 		   (slave->status == SDW_SLAVE_UNATTACHED)) {
831 		dev_dbg(&slave->dev,
832 			"%s: signaling enumeration completion for Slave %d\n",
833 			__func__, slave->dev_num);
834 
835 		complete(&slave->enumeration_complete);
836 	}
837 	slave->status = status;
838 	mutex_unlock(&bus->bus_lock);
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 			return ret;
851 	}
852 
853 	return 0;
854 }
855 
856 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
857 				      enum sdw_clk_stop_mode mode,
858 				      bool prepare)
859 {
860 	bool wake_en;
861 	u32 val = 0;
862 	int ret;
863 
864 	wake_en = slave->prop.wake_capable;
865 
866 	if (prepare) {
867 		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
868 
869 		if (mode == SDW_CLK_STOP_MODE1)
870 			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
871 
872 		if (wake_en)
873 			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
874 	} else {
875 		ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
876 		if (ret < 0) {
877 			if (ret != -ENODATA)
878 				dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
879 			return ret;
880 		}
881 		val = ret;
882 		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
883 	}
884 
885 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
886 
887 	if (ret < 0 && ret != -ENODATA)
888 		dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL write failed:%d\n", ret);
889 
890 	return ret;
891 }
892 
893 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
894 {
895 	int retry = bus->clk_stop_timeout;
896 	int val;
897 
898 	do {
899 		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT);
900 		if (val < 0) {
901 			if (val != -ENODATA)
902 				dev_err(bus->dev, "SDW_SCP_STAT bread failed:%d\n", val);
903 			return val;
904 		}
905 		val &= SDW_SCP_STAT_CLK_STP_NF;
906 		if (!val) {
907 			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d\n",
908 				dev_num);
909 			return 0;
910 		}
911 
912 		usleep_range(1000, 1500);
913 		retry--;
914 	} while (retry);
915 
916 	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d\n",
917 		dev_num);
918 
919 	return -ETIMEDOUT;
920 }
921 
922 /**
923  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
924  *
925  * @bus: SDW bus instance
926  *
927  * Query Slave for clock stop mode and prepare for that mode.
928  */
929 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
930 {
931 	bool simple_clk_stop = true;
932 	struct sdw_slave *slave;
933 	bool is_slave = false;
934 	int ret = 0;
935 
936 	/*
937 	 * In order to save on transition time, prepare
938 	 * each Slave and then wait for all Slave(s) to be
939 	 * prepared for clock stop.
940 	 * If one of the Slave devices has lost sync and
941 	 * replies with Command Ignored/-ENODATA, we continue
942 	 * the loop
943 	 */
944 	list_for_each_entry(slave, &bus->slaves, node) {
945 		if (!slave->dev_num)
946 			continue;
947 
948 		if (slave->status != SDW_SLAVE_ATTACHED &&
949 		    slave->status != SDW_SLAVE_ALERT)
950 			continue;
951 
952 		/* Identify if Slave(s) are available on Bus */
953 		is_slave = true;
954 
955 		ret = sdw_slave_clk_stop_callback(slave,
956 						  SDW_CLK_STOP_MODE0,
957 						  SDW_CLK_PRE_PREPARE);
958 		if (ret < 0 && ret != -ENODATA) {
959 			dev_err(&slave->dev, "clock stop pre-prepare cb failed:%d\n", ret);
960 			return ret;
961 		}
962 
963 		/* Only prepare a Slave device if needed */
964 		if (!slave->prop.simple_clk_stop_capable) {
965 			simple_clk_stop = false;
966 
967 			ret = sdw_slave_clk_stop_prepare(slave,
968 							 SDW_CLK_STOP_MODE0,
969 							 true);
970 			if (ret < 0 && ret != -ENODATA) {
971 				dev_err(&slave->dev, "clock stop prepare failed:%d\n", ret);
972 				return ret;
973 			}
974 		}
975 	}
976 
977 	/* Skip remaining clock stop preparation if no Slave is attached */
978 	if (!is_slave)
979 		return 0;
980 
981 	/*
982 	 * Don't wait for all Slaves to be ready if they follow the simple
983 	 * state machine
984 	 */
985 	if (!simple_clk_stop) {
986 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
987 						       SDW_BROADCAST_DEV_NUM);
988 		/*
989 		 * if there are no Slave devices present and the reply is
990 		 * Command_Ignored/-ENODATA, we don't need to continue with the
991 		 * flow and can just return here. The error code is not modified
992 		 * and its handling left as an exercise for the caller.
993 		 */
994 		if (ret < 0)
995 			return ret;
996 	}
997 
998 	/* Inform slaves that prep is done */
999 	list_for_each_entry(slave, &bus->slaves, node) {
1000 		if (!slave->dev_num)
1001 			continue;
1002 
1003 		if (slave->status != SDW_SLAVE_ATTACHED &&
1004 		    slave->status != SDW_SLAVE_ALERT)
1005 			continue;
1006 
1007 		ret = sdw_slave_clk_stop_callback(slave,
1008 						  SDW_CLK_STOP_MODE0,
1009 						  SDW_CLK_POST_PREPARE);
1010 
1011 		if (ret < 0 && ret != -ENODATA) {
1012 			dev_err(&slave->dev, "clock stop post-prepare cb failed:%d\n", ret);
1013 			return ret;
1014 		}
1015 	}
1016 
1017 	return 0;
1018 }
1019 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
1020 
1021 /**
1022  * sdw_bus_clk_stop: stop bus clock
1023  *
1024  * @bus: SDW bus instance
1025  *
1026  * After preparing the Slaves for clock stop, stop the clock by broadcasting
1027  * write to SCP_CTRL register.
1028  */
1029 int sdw_bus_clk_stop(struct sdw_bus *bus)
1030 {
1031 	int ret;
1032 
1033 	/*
1034 	 * broadcast clock stop now, attached Slaves will ACK this,
1035 	 * unattached will ignore
1036 	 */
1037 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1038 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1039 	if (ret < 0) {
1040 		if (ret != -ENODATA)
1041 			dev_err(bus->dev, "ClockStopNow Broadcast msg failed %d\n", ret);
1042 		return ret;
1043 	}
1044 
1045 	return 0;
1046 }
1047 EXPORT_SYMBOL(sdw_bus_clk_stop);
1048 
1049 /**
1050  * sdw_bus_exit_clk_stop: Exit clock stop mode
1051  *
1052  * @bus: SDW bus instance
1053  *
1054  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1055  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1056  * back.
1057  */
1058 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1059 {
1060 	bool simple_clk_stop = true;
1061 	struct sdw_slave *slave;
1062 	bool is_slave = false;
1063 	int ret;
1064 
1065 	/*
1066 	 * In order to save on transition time, de-prepare
1067 	 * each Slave and then wait for all Slave(s) to be
1068 	 * de-prepared after clock resume.
1069 	 */
1070 	list_for_each_entry(slave, &bus->slaves, node) {
1071 		if (!slave->dev_num)
1072 			continue;
1073 
1074 		if (slave->status != SDW_SLAVE_ATTACHED &&
1075 		    slave->status != SDW_SLAVE_ALERT)
1076 			continue;
1077 
1078 		/* Identify if Slave(s) are available on Bus */
1079 		is_slave = true;
1080 
1081 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1082 						  SDW_CLK_PRE_DEPREPARE);
1083 		if (ret < 0)
1084 			dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);
1085 
1086 		/* Only de-prepare a Slave device if needed */
1087 		if (!slave->prop.simple_clk_stop_capable) {
1088 			simple_clk_stop = false;
1089 
1090 			ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
1091 							 false);
1092 
1093 			if (ret < 0)
1094 				dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret);
1095 		}
1096 	}
1097 
1098 	/* Skip remaining clock stop de-preparation if no Slave is attached */
1099 	if (!is_slave)
1100 		return 0;
1101 
1102 	/*
1103 	 * Don't wait for all Slaves to be ready if they follow the simple
1104 	 * state machine
1105 	 */
1106 	if (!simple_clk_stop) {
1107 		ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1108 		if (ret < 0)
1109 			dev_warn(bus->dev, "clock stop deprepare wait failed:%d\n", ret);
1110 	}
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 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1121 						  SDW_CLK_POST_DEPREPARE);
1122 		if (ret < 0)
1123 			dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret);
1124 	}
1125 
1126 	return 0;
1127 }
1128 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1129 
1130 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1131 			   int port, bool enable, int mask)
1132 {
1133 	u32 addr;
1134 	int ret;
1135 	u8 val = 0;
1136 
1137 	if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1138 		dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1139 			enable ? "on" : "off");
1140 		mask |= SDW_DPN_INT_TEST_FAIL;
1141 	}
1142 
1143 	addr = SDW_DPN_INTMASK(port);
1144 
1145 	/* Set/Clear port ready interrupt mask */
1146 	if (enable) {
1147 		val |= mask;
1148 		val |= SDW_DPN_INT_PORT_READY;
1149 	} else {
1150 		val &= ~(mask);
1151 		val &= ~SDW_DPN_INT_PORT_READY;
1152 	}
1153 
1154 	ret = sdw_update(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1155 	if (ret < 0)
1156 		dev_err(&slave->dev,
1157 			"SDW_DPN_INTMASK write failed:%d\n", val);
1158 
1159 	return ret;
1160 }
1161 
1162 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1163 {
1164 	u32 mclk_freq = slave->bus->prop.mclk_freq;
1165 	u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1166 	unsigned int scale;
1167 	u8 scale_index;
1168 	u8 base;
1169 	int ret;
1170 
1171 	/*
1172 	 * frequency base and scale registers are required for SDCA
1173 	 * devices. They may also be used for 1.2+/non-SDCA devices,
1174 	 * but we will need a DisCo property to cover this case
1175 	 */
1176 	if (!slave->id.class_id)
1177 		return 0;
1178 
1179 	if (!mclk_freq) {
1180 		dev_err(&slave->dev,
1181 			"no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1182 		return -EINVAL;
1183 	}
1184 
1185 	/*
1186 	 * map base frequency using Table 89 of SoundWire 1.2 spec.
1187 	 * The order of the tests just follows the specification, this
1188 	 * is not a selection between possible values or a search for
1189 	 * the best value but just a mapping.  Only one case per platform
1190 	 * is relevant.
1191 	 * Some BIOS have inconsistent values for mclk_freq but a
1192 	 * correct root so we force the mclk_freq to avoid variations.
1193 	 */
1194 	if (!(19200000 % mclk_freq)) {
1195 		mclk_freq = 19200000;
1196 		base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1197 	} else if (!(24000000 % mclk_freq)) {
1198 		mclk_freq = 24000000;
1199 		base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1200 	} else if (!(24576000 % mclk_freq)) {
1201 		mclk_freq = 24576000;
1202 		base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1203 	} else if (!(22579200 % mclk_freq)) {
1204 		mclk_freq = 22579200;
1205 		base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1206 	} else if (!(32000000 % mclk_freq)) {
1207 		mclk_freq = 32000000;
1208 		base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1209 	} else {
1210 		dev_err(&slave->dev,
1211 			"Unsupported clock base, mclk %d\n",
1212 			mclk_freq);
1213 		return -EINVAL;
1214 	}
1215 
1216 	if (mclk_freq % curr_freq) {
1217 		dev_err(&slave->dev,
1218 			"mclk %d is not multiple of bus curr_freq %d\n",
1219 			mclk_freq, curr_freq);
1220 		return -EINVAL;
1221 	}
1222 
1223 	scale = mclk_freq / curr_freq;
1224 
1225 	/*
1226 	 * map scale to Table 90 of SoundWire 1.2 spec - and check
1227 	 * that the scale is a power of two and maximum 64
1228 	 */
1229 	scale_index = ilog2(scale);
1230 
1231 	if (BIT(scale_index) != scale || scale_index > 6) {
1232 		dev_err(&slave->dev,
1233 			"No match found for scale %d, bus mclk %d curr_freq %d\n",
1234 			scale, mclk_freq, curr_freq);
1235 		return -EINVAL;
1236 	}
1237 	scale_index++;
1238 
1239 	ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1240 	if (ret < 0) {
1241 		dev_err(&slave->dev,
1242 			"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1243 		return ret;
1244 	}
1245 
1246 	/* initialize scale for both banks */
1247 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1248 	if (ret < 0) {
1249 		dev_err(&slave->dev,
1250 			"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1251 		return ret;
1252 	}
1253 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1254 	if (ret < 0)
1255 		dev_err(&slave->dev,
1256 			"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1257 
1258 	dev_dbg(&slave->dev,
1259 		"Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1260 		base, scale_index, mclk_freq, curr_freq);
1261 
1262 	return ret;
1263 }
1264 
1265 static int sdw_initialize_slave(struct sdw_slave *slave)
1266 {
1267 	struct sdw_slave_prop *prop = &slave->prop;
1268 	int status;
1269 	int ret;
1270 	u8 val;
1271 
1272 	ret = sdw_slave_set_frequency(slave);
1273 	if (ret < 0)
1274 		return ret;
1275 
1276 	if (slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH) {
1277 		/* Clear bus clash interrupt before enabling interrupt mask */
1278 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1279 		if (status < 0) {
1280 			dev_err(&slave->dev,
1281 				"SDW_SCP_INT1 (BUS_CLASH) read failed:%d\n", status);
1282 			return status;
1283 		}
1284 		if (status & SDW_SCP_INT1_BUS_CLASH) {
1285 			dev_warn(&slave->dev, "Bus clash detected before INT mask is enabled\n");
1286 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH);
1287 			if (ret < 0) {
1288 				dev_err(&slave->dev,
1289 					"SDW_SCP_INT1 (BUS_CLASH) write failed:%d\n", ret);
1290 				return ret;
1291 			}
1292 		}
1293 	}
1294 	if ((slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY) &&
1295 	    !(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY)) {
1296 		/* Clear parity interrupt before enabling interrupt mask */
1297 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1298 		if (status < 0) {
1299 			dev_err(&slave->dev,
1300 				"SDW_SCP_INT1 (PARITY) read failed:%d\n", status);
1301 			return status;
1302 		}
1303 		if (status & SDW_SCP_INT1_PARITY) {
1304 			dev_warn(&slave->dev, "PARITY error detected before INT mask is enabled\n");
1305 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_PARITY);
1306 			if (ret < 0) {
1307 				dev_err(&slave->dev,
1308 					"SDW_SCP_INT1 (PARITY) write failed:%d\n", ret);
1309 				return ret;
1310 			}
1311 		}
1312 	}
1313 
1314 	/*
1315 	 * Set SCP_INT1_MASK register, typically bus clash and
1316 	 * implementation-defined interrupt mask. The Parity detection
1317 	 * may not always be correct on startup so its use is
1318 	 * device-dependent, it might e.g. only be enabled in
1319 	 * steady-state after a couple of frames.
1320 	 */
1321 	val = slave->prop.scp_int1_mask;
1322 
1323 	/* Enable SCP interrupts */
1324 	ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
1325 	if (ret < 0) {
1326 		dev_err(&slave->dev,
1327 			"SDW_SCP_INTMASK1 write failed:%d\n", ret);
1328 		return ret;
1329 	}
1330 
1331 	/* No need to continue if DP0 is not present */
1332 	if (!slave->prop.dp0_prop)
1333 		return 0;
1334 
1335 	/* Enable DP0 interrupts */
1336 	val = prop->dp0_prop->imp_def_interrupts;
1337 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1338 
1339 	ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
1340 	if (ret < 0)
1341 		dev_err(&slave->dev,
1342 			"SDW_DP0_INTMASK read failed:%d\n", ret);
1343 	return ret;
1344 }
1345 
1346 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1347 {
1348 	u8 clear, impl_int_mask;
1349 	int status, status2, ret, count = 0;
1350 
1351 	status = sdw_read_no_pm(slave, SDW_DP0_INT);
1352 	if (status < 0) {
1353 		dev_err(&slave->dev,
1354 			"SDW_DP0_INT read failed:%d\n", status);
1355 		return status;
1356 	}
1357 
1358 	do {
1359 		clear = status & ~SDW_DP0_INTERRUPTS;
1360 
1361 		if (status & SDW_DP0_INT_TEST_FAIL) {
1362 			dev_err(&slave->dev, "Test fail for port 0\n");
1363 			clear |= SDW_DP0_INT_TEST_FAIL;
1364 		}
1365 
1366 		/*
1367 		 * Assumption: PORT_READY interrupt will be received only for
1368 		 * ports implementing Channel Prepare state machine (CP_SM)
1369 		 */
1370 
1371 		if (status & SDW_DP0_INT_PORT_READY) {
1372 			complete(&slave->port_ready[0]);
1373 			clear |= SDW_DP0_INT_PORT_READY;
1374 		}
1375 
1376 		if (status & SDW_DP0_INT_BRA_FAILURE) {
1377 			dev_err(&slave->dev, "BRA failed\n");
1378 			clear |= SDW_DP0_INT_BRA_FAILURE;
1379 		}
1380 
1381 		impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1382 			SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1383 
1384 		if (status & impl_int_mask) {
1385 			clear |= impl_int_mask;
1386 			*slave_status = clear;
1387 		}
1388 
1389 		/* clear the interrupts but don't touch reserved and SDCA_CASCADE fields */
1390 		ret = sdw_write_no_pm(slave, SDW_DP0_INT, clear);
1391 		if (ret < 0) {
1392 			dev_err(&slave->dev,
1393 				"SDW_DP0_INT write failed:%d\n", ret);
1394 			return ret;
1395 		}
1396 
1397 		/* Read DP0 interrupt again */
1398 		status2 = sdw_read_no_pm(slave, SDW_DP0_INT);
1399 		if (status2 < 0) {
1400 			dev_err(&slave->dev,
1401 				"SDW_DP0_INT read failed:%d\n", status2);
1402 			return status2;
1403 		}
1404 		/* filter to limit loop to interrupts identified in the first status read */
1405 		status &= status2;
1406 
1407 		count++;
1408 
1409 		/* we can get alerts while processing so keep retrying */
1410 	} while ((status & SDW_DP0_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1411 
1412 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1413 		dev_warn(&slave->dev, "Reached MAX_RETRY on DP0 read\n");
1414 
1415 	return ret;
1416 }
1417 
1418 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1419 				     int port, u8 *slave_status)
1420 {
1421 	u8 clear, impl_int_mask;
1422 	int status, status2, ret, count = 0;
1423 	u32 addr;
1424 
1425 	if (port == 0)
1426 		return sdw_handle_dp0_interrupt(slave, slave_status);
1427 
1428 	addr = SDW_DPN_INT(port);
1429 	status = sdw_read_no_pm(slave, addr);
1430 	if (status < 0) {
1431 		dev_err(&slave->dev,
1432 			"SDW_DPN_INT read failed:%d\n", status);
1433 
1434 		return status;
1435 	}
1436 
1437 	do {
1438 		clear = status & ~SDW_DPN_INTERRUPTS;
1439 
1440 		if (status & SDW_DPN_INT_TEST_FAIL) {
1441 			dev_err(&slave->dev, "Test fail for port:%d\n", port);
1442 			clear |= SDW_DPN_INT_TEST_FAIL;
1443 		}
1444 
1445 		/*
1446 		 * Assumption: PORT_READY interrupt will be received only
1447 		 * for ports implementing CP_SM.
1448 		 */
1449 		if (status & SDW_DPN_INT_PORT_READY) {
1450 			complete(&slave->port_ready[port]);
1451 			clear |= SDW_DPN_INT_PORT_READY;
1452 		}
1453 
1454 		impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1455 			SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1456 
1457 		if (status & impl_int_mask) {
1458 			clear |= impl_int_mask;
1459 			*slave_status = clear;
1460 		}
1461 
1462 		/* clear the interrupt but don't touch reserved fields */
1463 		ret = sdw_write_no_pm(slave, addr, clear);
1464 		if (ret < 0) {
1465 			dev_err(&slave->dev,
1466 				"SDW_DPN_INT write failed:%d\n", ret);
1467 			return ret;
1468 		}
1469 
1470 		/* Read DPN interrupt again */
1471 		status2 = sdw_read_no_pm(slave, addr);
1472 		if (status2 < 0) {
1473 			dev_err(&slave->dev,
1474 				"SDW_DPN_INT read failed:%d\n", status2);
1475 			return status2;
1476 		}
1477 		/* filter to limit loop to interrupts identified in the first status read */
1478 		status &= status2;
1479 
1480 		count++;
1481 
1482 		/* we can get alerts while processing so keep retrying */
1483 	} while ((status & SDW_DPN_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1484 
1485 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1486 		dev_warn(&slave->dev, "Reached MAX_RETRY on port read");
1487 
1488 	return ret;
1489 }
1490 
1491 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1492 {
1493 	struct sdw_slave_intr_status slave_intr;
1494 	u8 clear = 0, bit, port_status[15] = {0};
1495 	int port_num, stat, ret, count = 0;
1496 	unsigned long port;
1497 	bool slave_notify;
1498 	u8 sdca_cascade = 0;
1499 	u8 buf, buf2[2], _buf, _buf2[2];
1500 	bool parity_check;
1501 	bool parity_quirk;
1502 
1503 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1504 
1505 	ret = pm_runtime_resume_and_get(&slave->dev);
1506 	if (ret < 0 && ret != -EACCES) {
1507 		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
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 			dev_warn(&slave->dev, "Slave %d state check1: UNATTACHED, status was %d\n",
1749 				 i, slave->status);
1750 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1751 		}
1752 	}
1753 
1754 	if (status[0] == SDW_SLAVE_ATTACHED) {
1755 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
1756 		ret = sdw_program_device_num(bus);
1757 		if (ret < 0)
1758 			dev_err(bus->dev, "Slave attach failed: %d\n", ret);
1759 		/*
1760 		 * programming a device number will have side effects,
1761 		 * so we deal with other devices at a later time
1762 		 */
1763 		return ret;
1764 	}
1765 
1766 	/* Continue to check other slave statuses */
1767 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1768 		mutex_lock(&bus->bus_lock);
1769 		if (test_bit(i, bus->assigned) == false) {
1770 			mutex_unlock(&bus->bus_lock);
1771 			continue;
1772 		}
1773 		mutex_unlock(&bus->bus_lock);
1774 
1775 		slave = sdw_get_slave(bus, i);
1776 		if (!slave)
1777 			continue;
1778 
1779 		attached_initializing = false;
1780 
1781 		switch (status[i]) {
1782 		case SDW_SLAVE_UNATTACHED:
1783 			if (slave->status == SDW_SLAVE_UNATTACHED)
1784 				break;
1785 
1786 			dev_warn(&slave->dev, "Slave %d state check2: UNATTACHED, status was %d\n",
1787 				 i, slave->status);
1788 
1789 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1790 			break;
1791 
1792 		case SDW_SLAVE_ALERT:
1793 			ret = sdw_handle_slave_alerts(slave);
1794 			if (ret < 0)
1795 				dev_err(&slave->dev,
1796 					"Slave %d alert handling failed: %d\n",
1797 					i, ret);
1798 			break;
1799 
1800 		case SDW_SLAVE_ATTACHED:
1801 			if (slave->status == SDW_SLAVE_ATTACHED)
1802 				break;
1803 
1804 			prev_status = slave->status;
1805 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1806 
1807 			if (prev_status == SDW_SLAVE_ALERT)
1808 				break;
1809 
1810 			attached_initializing = true;
1811 
1812 			ret = sdw_initialize_slave(slave);
1813 			if (ret < 0)
1814 				dev_err(&slave->dev,
1815 					"Slave %d initialization failed: %d\n",
1816 					i, ret);
1817 
1818 			break;
1819 
1820 		default:
1821 			dev_err(&slave->dev, "Invalid slave %d status:%d\n",
1822 				i, status[i]);
1823 			break;
1824 		}
1825 
1826 		ret = sdw_update_slave_status(slave, status[i]);
1827 		if (ret < 0)
1828 			dev_err(&slave->dev,
1829 				"Update Slave status failed:%d\n", ret);
1830 		if (attached_initializing) {
1831 			dev_dbg(&slave->dev,
1832 				"%s: signaling initialization completion for Slave %d\n",
1833 				__func__, slave->dev_num);
1834 
1835 			complete(&slave->initialization_complete);
1836 
1837 			/*
1838 			 * If the manager became pm_runtime active, the peripherals will be
1839 			 * restarted and attach, but their pm_runtime status may remain
1840 			 * suspended. If the 'update_slave_status' callback initiates
1841 			 * any sort of deferred processing, this processing would not be
1842 			 * cancelled on pm_runtime suspend.
1843 			 * To avoid such zombie states, we queue a request to resume.
1844 			 * This would be a no-op in case the peripheral was being resumed
1845 			 * by e.g. the ALSA/ASoC framework.
1846 			 */
1847 			pm_request_resume(&slave->dev);
1848 		}
1849 	}
1850 
1851 	return ret;
1852 }
1853 EXPORT_SYMBOL(sdw_handle_slave_status);
1854 
1855 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1856 {
1857 	struct sdw_slave *slave;
1858 	int i;
1859 
1860 	/* Check all non-zero devices */
1861 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1862 		mutex_lock(&bus->bus_lock);
1863 		if (test_bit(i, bus->assigned) == false) {
1864 			mutex_unlock(&bus->bus_lock);
1865 			continue;
1866 		}
1867 		mutex_unlock(&bus->bus_lock);
1868 
1869 		slave = sdw_get_slave(bus, i);
1870 		if (!slave)
1871 			continue;
1872 
1873 		if (slave->status != SDW_SLAVE_UNATTACHED) {
1874 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1875 			slave->first_interrupt_done = false;
1876 			sdw_update_slave_status(slave, SDW_SLAVE_UNATTACHED);
1877 		}
1878 
1879 		/* keep track of request, used in pm_runtime resume */
1880 		slave->unattach_request = request;
1881 	}
1882 }
1883 EXPORT_SYMBOL(sdw_clear_slave_status);
1884