xref: /linux/drivers/soundwire/bus.c (revision cf21f328fcafacf4f96e7a30ef9dceede1076378)
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 <linux/soundwire/sdw_type.h>
11 #include "bus.h"
12 #include "sysfs_local.h"
13 
14 static DEFINE_IDA(sdw_bus_ida);
15 static DEFINE_IDA(sdw_peripheral_ida);
16 
17 static int sdw_get_id(struct sdw_bus *bus)
18 {
19 	int rc = ida_alloc(&sdw_bus_ida, GFP_KERNEL);
20 
21 	if (rc < 0)
22 		return rc;
23 
24 	bus->id = rc;
25 	return 0;
26 }
27 
28 /**
29  * sdw_bus_master_add() - add a bus Master instance
30  * @bus: bus instance
31  * @parent: parent device
32  * @fwnode: firmware node handle
33  *
34  * Initializes the bus instance, read properties and create child
35  * devices.
36  */
37 int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
38 		       struct fwnode_handle *fwnode)
39 {
40 	struct sdw_master_prop *prop = NULL;
41 	int ret;
42 
43 	if (!parent) {
44 		pr_err("SoundWire parent device is not set\n");
45 		return -ENODEV;
46 	}
47 
48 	ret = sdw_get_id(bus);
49 	if (ret < 0) {
50 		dev_err(parent, "Failed to get bus id\n");
51 		return ret;
52 	}
53 
54 	ret = sdw_master_device_add(bus, parent, fwnode);
55 	if (ret < 0) {
56 		dev_err(parent, "Failed to add master device at link %d\n",
57 			bus->link_id);
58 		return ret;
59 	}
60 
61 	if (!bus->ops) {
62 		dev_err(bus->dev, "SoundWire Bus ops are not set\n");
63 		return -EINVAL;
64 	}
65 
66 	if (!bus->compute_params) {
67 		dev_err(bus->dev,
68 			"Bandwidth allocation not configured, compute_params no set\n");
69 		return -EINVAL;
70 	}
71 
72 	mutex_init(&bus->msg_lock);
73 	mutex_init(&bus->bus_lock);
74 	INIT_LIST_HEAD(&bus->slaves);
75 	INIT_LIST_HEAD(&bus->m_rt_list);
76 
77 	/*
78 	 * Initialize multi_link flag
79 	 */
80 	bus->multi_link = false;
81 	if (bus->ops->read_prop) {
82 		ret = bus->ops->read_prop(bus);
83 		if (ret < 0) {
84 			dev_err(bus->dev,
85 				"Bus read properties failed:%d\n", ret);
86 			return ret;
87 		}
88 	}
89 
90 	sdw_bus_debugfs_init(bus);
91 
92 	/*
93 	 * Device numbers in SoundWire are 0 through 15. Enumeration device
94 	 * number (0), Broadcast device number (15), Group numbers (12 and
95 	 * 13) and Master device number (14) are not used for assignment so
96 	 * mask these and other higher bits.
97 	 */
98 
99 	/* Set higher order bits */
100 	*bus->assigned = ~GENMASK(SDW_BROADCAST_DEV_NUM, SDW_ENUM_DEV_NUM);
101 
102 	/* Set enumuration device number and broadcast device number */
103 	set_bit(SDW_ENUM_DEV_NUM, bus->assigned);
104 	set_bit(SDW_BROADCAST_DEV_NUM, bus->assigned);
105 
106 	/* Set group device numbers and master device number */
107 	set_bit(SDW_GROUP12_DEV_NUM, bus->assigned);
108 	set_bit(SDW_GROUP13_DEV_NUM, bus->assigned);
109 	set_bit(SDW_MASTER_DEV_NUM, bus->assigned);
110 
111 	/*
112 	 * SDW is an enumerable bus, but devices can be powered off. So,
113 	 * they won't be able to report as present.
114 	 *
115 	 * Create Slave devices based on Slaves described in
116 	 * the respective firmware (ACPI/DT)
117 	 */
118 	if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev))
119 		ret = sdw_acpi_find_slaves(bus);
120 	else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node)
121 		ret = sdw_of_find_slaves(bus);
122 	else
123 		ret = -ENOTSUPP; /* No ACPI/DT so error out */
124 
125 	if (ret < 0) {
126 		dev_err(bus->dev, "Finding slaves failed:%d\n", ret);
127 		return ret;
128 	}
129 
130 	/*
131 	 * Initialize clock values based on Master properties. The max
132 	 * frequency is read from max_clk_freq property. Current assumption
133 	 * is that the bus will start at highest clock frequency when
134 	 * powered on.
135 	 *
136 	 * Default active bank will be 0 as out of reset the Slaves have
137 	 * to start with bank 0 (Table 40 of Spec)
138 	 */
139 	prop = &bus->prop;
140 	bus->params.max_dr_freq = prop->max_clk_freq * SDW_DOUBLE_RATE_FACTOR;
141 	bus->params.curr_dr_freq = bus->params.max_dr_freq;
142 	bus->params.curr_bank = SDW_BANK0;
143 	bus->params.next_bank = SDW_BANK1;
144 
145 	return 0;
146 }
147 EXPORT_SYMBOL(sdw_bus_master_add);
148 
149 static int sdw_delete_slave(struct device *dev, void *data)
150 {
151 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
152 	struct sdw_bus *bus = slave->bus;
153 
154 	pm_runtime_disable(dev);
155 
156 	sdw_slave_debugfs_exit(slave);
157 
158 	mutex_lock(&bus->bus_lock);
159 
160 	if (slave->dev_num) { /* clear dev_num if assigned */
161 		clear_bit(slave->dev_num, bus->assigned);
162 		if (bus->dev_num_ida_min)
163 			ida_free(&sdw_peripheral_ida, slave->dev_num);
164 	}
165 	list_del_init(&slave->node);
166 	mutex_unlock(&bus->bus_lock);
167 
168 	device_unregister(dev);
169 	return 0;
170 }
171 
172 /**
173  * sdw_bus_master_delete() - delete the bus master instance
174  * @bus: bus to be deleted
175  *
176  * Remove the instance, delete the child devices.
177  */
178 void sdw_bus_master_delete(struct sdw_bus *bus)
179 {
180 	device_for_each_child(bus->dev, NULL, sdw_delete_slave);
181 	sdw_master_device_del(bus);
182 
183 	sdw_bus_debugfs_exit(bus);
184 	ida_free(&sdw_bus_ida, bus->id);
185 }
186 EXPORT_SYMBOL(sdw_bus_master_delete);
187 
188 /*
189  * SDW IO Calls
190  */
191 
192 static inline int find_response_code(enum sdw_command_response resp)
193 {
194 	switch (resp) {
195 	case SDW_CMD_OK:
196 		return 0;
197 
198 	case SDW_CMD_IGNORED:
199 		return -ENODATA;
200 
201 	case SDW_CMD_TIMEOUT:
202 		return -ETIMEDOUT;
203 
204 	default:
205 		return -EIO;
206 	}
207 }
208 
209 static inline int do_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
210 {
211 	int retry = bus->prop.err_threshold;
212 	enum sdw_command_response resp;
213 	int ret = 0, i;
214 
215 	for (i = 0; i <= retry; i++) {
216 		resp = bus->ops->xfer_msg(bus, msg);
217 		ret = find_response_code(resp);
218 
219 		/* if cmd is ok or ignored return */
220 		if (ret == 0 || ret == -ENODATA)
221 			return ret;
222 	}
223 
224 	return ret;
225 }
226 
227 static inline int do_transfer_defer(struct sdw_bus *bus,
228 				    struct sdw_msg *msg)
229 {
230 	struct sdw_defer *defer = &bus->defer_msg;
231 	int retry = bus->prop.err_threshold;
232 	enum sdw_command_response resp;
233 	int ret = 0, i;
234 
235 	defer->msg = msg;
236 	defer->length = msg->len;
237 	init_completion(&defer->complete);
238 
239 	for (i = 0; i <= retry; i++) {
240 		resp = bus->ops->xfer_msg_defer(bus);
241 		ret = find_response_code(resp);
242 		/* if cmd is ok or ignored return */
243 		if (ret == 0 || ret == -ENODATA)
244 			return ret;
245 	}
246 
247 	return ret;
248 }
249 
250 static int sdw_transfer_unlocked(struct sdw_bus *bus, struct sdw_msg *msg)
251 {
252 	int ret;
253 
254 	ret = do_transfer(bus, msg);
255 	if (ret != 0 && ret != -ENODATA)
256 		dev_err(bus->dev, "trf on Slave %d failed:%d %s addr %x count %d\n",
257 			msg->dev_num, ret,
258 			(msg->flags & SDW_MSG_FLAG_WRITE) ? "write" : "read",
259 			msg->addr, msg->len);
260 
261 	return ret;
262 }
263 
264 /**
265  * sdw_transfer() - Synchronous transfer message to a SDW Slave device
266  * @bus: SDW bus
267  * @msg: SDW message to be xfered
268  */
269 int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
270 {
271 	int ret;
272 
273 	mutex_lock(&bus->msg_lock);
274 
275 	ret = sdw_transfer_unlocked(bus, msg);
276 
277 	mutex_unlock(&bus->msg_lock);
278 
279 	return ret;
280 }
281 
282 /**
283  * sdw_show_ping_status() - Direct report of PING status, to be used by Peripheral drivers
284  * @bus: SDW bus
285  * @sync_delay: Delay before reading status
286  */
287 void sdw_show_ping_status(struct sdw_bus *bus, bool sync_delay)
288 {
289 	u32 status;
290 
291 	if (!bus->ops->read_ping_status)
292 		return;
293 
294 	/*
295 	 * wait for peripheral to sync if desired. 10-15ms should be more than
296 	 * enough in most cases.
297 	 */
298 	if (sync_delay)
299 		usleep_range(10000, 15000);
300 
301 	mutex_lock(&bus->msg_lock);
302 
303 	status = bus->ops->read_ping_status(bus);
304 
305 	mutex_unlock(&bus->msg_lock);
306 
307 	if (!status)
308 		dev_warn(bus->dev, "%s: no peripherals attached\n", __func__);
309 	else
310 		dev_dbg(bus->dev, "PING status: %#x\n", status);
311 }
312 EXPORT_SYMBOL(sdw_show_ping_status);
313 
314 /**
315  * sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
316  * @bus: SDW bus
317  * @msg: SDW message to be xfered
318  *
319  * Caller needs to hold the msg_lock lock while calling this
320  */
321 int sdw_transfer_defer(struct sdw_bus *bus, struct sdw_msg *msg)
322 {
323 	int ret;
324 
325 	if (!bus->ops->xfer_msg_defer)
326 		return -ENOTSUPP;
327 
328 	ret = do_transfer_defer(bus, msg);
329 	if (ret != 0 && ret != -ENODATA)
330 		dev_err(bus->dev, "Defer trf on Slave %d failed:%d\n",
331 			msg->dev_num, ret);
332 
333 	return ret;
334 }
335 
336 int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
337 		 u32 addr, size_t count, u16 dev_num, u8 flags, u8 *buf)
338 {
339 	memset(msg, 0, sizeof(*msg));
340 	msg->addr = addr; /* addr is 16 bit and truncated here */
341 	msg->len = count;
342 	msg->dev_num = dev_num;
343 	msg->flags = flags;
344 	msg->buf = buf;
345 
346 	if (addr < SDW_REG_NO_PAGE) /* no paging area */
347 		return 0;
348 
349 	if (addr >= SDW_REG_MAX) { /* illegal addr */
350 		pr_err("SDW: Invalid address %x passed\n", addr);
351 		return -EINVAL;
352 	}
353 
354 	if (addr < SDW_REG_OPTIONAL_PAGE) { /* 32k but no page */
355 		if (slave && !slave->prop.paging_support)
356 			return 0;
357 		/* no need for else as that will fall-through to paging */
358 	}
359 
360 	/* paging mandatory */
361 	if (dev_num == SDW_ENUM_DEV_NUM || dev_num == SDW_BROADCAST_DEV_NUM) {
362 		pr_err("SDW: Invalid device for paging :%d\n", dev_num);
363 		return -EINVAL;
364 	}
365 
366 	if (!slave) {
367 		pr_err("SDW: No slave for paging addr\n");
368 		return -EINVAL;
369 	}
370 
371 	if (!slave->prop.paging_support) {
372 		dev_err(&slave->dev,
373 			"address %x needs paging but no support\n", addr);
374 		return -EINVAL;
375 	}
376 
377 	msg->addr_page1 = FIELD_GET(SDW_SCP_ADDRPAGE1_MASK, addr);
378 	msg->addr_page2 = FIELD_GET(SDW_SCP_ADDRPAGE2_MASK, addr);
379 	msg->addr |= BIT(15);
380 	msg->page = true;
381 
382 	return 0;
383 }
384 
385 /*
386  * Read/Write IO functions.
387  * no_pm versions can only be called by the bus, e.g. while enumerating or
388  * handling suspend-resume sequences.
389  * all clients need to use the pm versions
390  */
391 
392 int sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
393 {
394 	struct sdw_msg msg;
395 	int ret;
396 
397 	ret = sdw_fill_msg(&msg, slave, addr, count,
398 			   slave->dev_num, SDW_MSG_FLAG_READ, val);
399 	if (ret < 0)
400 		return ret;
401 
402 	ret = sdw_transfer(slave->bus, &msg);
403 	if (slave->is_mockup_device)
404 		ret = 0;
405 	return ret;
406 }
407 EXPORT_SYMBOL(sdw_nread_no_pm);
408 
409 int sdw_nwrite_no_pm(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
410 {
411 	struct sdw_msg msg;
412 	int ret;
413 
414 	ret = sdw_fill_msg(&msg, slave, addr, count,
415 			   slave->dev_num, SDW_MSG_FLAG_WRITE, (u8 *)val);
416 	if (ret < 0)
417 		return ret;
418 
419 	ret = sdw_transfer(slave->bus, &msg);
420 	if (slave->is_mockup_device)
421 		ret = 0;
422 	return ret;
423 }
424 EXPORT_SYMBOL(sdw_nwrite_no_pm);
425 
426 int sdw_write_no_pm(struct sdw_slave *slave, u32 addr, u8 value)
427 {
428 	return sdw_nwrite_no_pm(slave, addr, 1, &value);
429 }
430 EXPORT_SYMBOL(sdw_write_no_pm);
431 
432 static int
433 sdw_bread_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr)
434 {
435 	struct sdw_msg msg;
436 	u8 buf;
437 	int ret;
438 
439 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
440 			   SDW_MSG_FLAG_READ, &buf);
441 	if (ret < 0)
442 		return ret;
443 
444 	ret = sdw_transfer(bus, &msg);
445 	if (ret < 0)
446 		return ret;
447 
448 	return buf;
449 }
450 
451 static int
452 sdw_bwrite_no_pm(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
453 {
454 	struct sdw_msg msg;
455 	int ret;
456 
457 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
458 			   SDW_MSG_FLAG_WRITE, &value);
459 	if (ret < 0)
460 		return ret;
461 
462 	return sdw_transfer(bus, &msg);
463 }
464 
465 int sdw_bread_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr)
466 {
467 	struct sdw_msg msg;
468 	u8 buf;
469 	int ret;
470 
471 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
472 			   SDW_MSG_FLAG_READ, &buf);
473 	if (ret < 0)
474 		return ret;
475 
476 	ret = sdw_transfer_unlocked(bus, &msg);
477 	if (ret < 0)
478 		return ret;
479 
480 	return buf;
481 }
482 EXPORT_SYMBOL(sdw_bread_no_pm_unlocked);
483 
484 int sdw_bwrite_no_pm_unlocked(struct sdw_bus *bus, u16 dev_num, u32 addr, u8 value)
485 {
486 	struct sdw_msg msg;
487 	int ret;
488 
489 	ret = sdw_fill_msg(&msg, NULL, addr, 1, dev_num,
490 			   SDW_MSG_FLAG_WRITE, &value);
491 	if (ret < 0)
492 		return ret;
493 
494 	return sdw_transfer_unlocked(bus, &msg);
495 }
496 EXPORT_SYMBOL(sdw_bwrite_no_pm_unlocked);
497 
498 int sdw_read_no_pm(struct sdw_slave *slave, u32 addr)
499 {
500 	u8 buf;
501 	int ret;
502 
503 	ret = sdw_nread_no_pm(slave, addr, 1, &buf);
504 	if (ret < 0)
505 		return ret;
506 	else
507 		return buf;
508 }
509 EXPORT_SYMBOL(sdw_read_no_pm);
510 
511 int sdw_update_no_pm(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
512 {
513 	int tmp;
514 
515 	tmp = sdw_read_no_pm(slave, addr);
516 	if (tmp < 0)
517 		return tmp;
518 
519 	tmp = (tmp & ~mask) | val;
520 	return sdw_write_no_pm(slave, addr, tmp);
521 }
522 EXPORT_SYMBOL(sdw_update_no_pm);
523 
524 /* Read-Modify-Write Slave register */
525 int sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
526 {
527 	int tmp;
528 
529 	tmp = sdw_read(slave, addr);
530 	if (tmp < 0)
531 		return tmp;
532 
533 	tmp = (tmp & ~mask) | val;
534 	return sdw_write(slave, addr, tmp);
535 }
536 EXPORT_SYMBOL(sdw_update);
537 
538 /**
539  * sdw_nread() - Read "n" contiguous SDW Slave registers
540  * @slave: SDW Slave
541  * @addr: Register address
542  * @count: length
543  * @val: Buffer for values to be read
544  */
545 int sdw_nread(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)
546 {
547 	int ret;
548 
549 	ret = pm_runtime_resume_and_get(&slave->dev);
550 	if (ret < 0 && ret != -EACCES)
551 		return ret;
552 
553 	ret = sdw_nread_no_pm(slave, addr, count, val);
554 
555 	pm_runtime_mark_last_busy(&slave->dev);
556 	pm_runtime_put(&slave->dev);
557 
558 	return ret;
559 }
560 EXPORT_SYMBOL(sdw_nread);
561 
562 /**
563  * sdw_nwrite() - Write "n" contiguous SDW Slave registers
564  * @slave: SDW Slave
565  * @addr: Register address
566  * @count: length
567  * @val: Buffer for values to be written
568  */
569 int sdw_nwrite(struct sdw_slave *slave, u32 addr, size_t count, const u8 *val)
570 {
571 	int ret;
572 
573 	ret = pm_runtime_resume_and_get(&slave->dev);
574 	if (ret < 0 && ret != -EACCES)
575 		return ret;
576 
577 	ret = sdw_nwrite_no_pm(slave, addr, count, val);
578 
579 	pm_runtime_mark_last_busy(&slave->dev);
580 	pm_runtime_put(&slave->dev);
581 
582 	return ret;
583 }
584 EXPORT_SYMBOL(sdw_nwrite);
585 
586 /**
587  * sdw_read() - Read a SDW Slave register
588  * @slave: SDW Slave
589  * @addr: Register address
590  */
591 int sdw_read(struct sdw_slave *slave, u32 addr)
592 {
593 	u8 buf;
594 	int ret;
595 
596 	ret = sdw_nread(slave, addr, 1, &buf);
597 	if (ret < 0)
598 		return ret;
599 
600 	return buf;
601 }
602 EXPORT_SYMBOL(sdw_read);
603 
604 /**
605  * sdw_write() - Write a SDW Slave register
606  * @slave: SDW Slave
607  * @addr: Register address
608  * @value: Register value
609  */
610 int sdw_write(struct sdw_slave *slave, u32 addr, u8 value)
611 {
612 	return sdw_nwrite(slave, addr, 1, &value);
613 }
614 EXPORT_SYMBOL(sdw_write);
615 
616 /*
617  * SDW alert handling
618  */
619 
620 /* called with bus_lock held */
621 static struct sdw_slave *sdw_get_slave(struct sdw_bus *bus, int i)
622 {
623 	struct sdw_slave *slave;
624 
625 	list_for_each_entry(slave, &bus->slaves, node) {
626 		if (slave->dev_num == i)
627 			return slave;
628 	}
629 
630 	return NULL;
631 }
632 
633 int sdw_compare_devid(struct sdw_slave *slave, struct sdw_slave_id id)
634 {
635 	if (slave->id.mfg_id != id.mfg_id ||
636 	    slave->id.part_id != id.part_id ||
637 	    slave->id.class_id != id.class_id ||
638 	    (slave->id.unique_id != SDW_IGNORED_UNIQUE_ID &&
639 	     slave->id.unique_id != id.unique_id))
640 		return -ENODEV;
641 
642 	return 0;
643 }
644 EXPORT_SYMBOL(sdw_compare_devid);
645 
646 /* called with bus_lock held */
647 static int sdw_get_device_num(struct sdw_slave *slave)
648 {
649 	int bit;
650 
651 	if (slave->bus->dev_num_ida_min) {
652 		bit = ida_alloc_range(&sdw_peripheral_ida,
653 				      slave->bus->dev_num_ida_min, SDW_MAX_DEVICES,
654 				      GFP_KERNEL);
655 		if (bit < 0)
656 			goto err;
657 	} else {
658 		bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
659 		if (bit == SDW_MAX_DEVICES) {
660 			bit = -ENODEV;
661 			goto err;
662 		}
663 	}
664 
665 	/*
666 	 * Do not update dev_num in Slave data structure here,
667 	 * Update once program dev_num is successful
668 	 */
669 	set_bit(bit, slave->bus->assigned);
670 
671 err:
672 	return bit;
673 }
674 
675 static int sdw_assign_device_num(struct sdw_slave *slave)
676 {
677 	struct sdw_bus *bus = slave->bus;
678 	int ret, dev_num;
679 	bool new_device = false;
680 
681 	/* check first if device number is assigned, if so reuse that */
682 	if (!slave->dev_num) {
683 		if (!slave->dev_num_sticky) {
684 			mutex_lock(&slave->bus->bus_lock);
685 			dev_num = sdw_get_device_num(slave);
686 			mutex_unlock(&slave->bus->bus_lock);
687 			if (dev_num < 0) {
688 				dev_err(bus->dev, "Get dev_num failed: %d\n",
689 					dev_num);
690 				return dev_num;
691 			}
692 			slave->dev_num = dev_num;
693 			slave->dev_num_sticky = dev_num;
694 			new_device = true;
695 		} else {
696 			slave->dev_num = slave->dev_num_sticky;
697 		}
698 	}
699 
700 	if (!new_device)
701 		dev_dbg(bus->dev,
702 			"Slave already registered, reusing dev_num:%d\n",
703 			slave->dev_num);
704 
705 	/* Clear the slave->dev_num to transfer message on device 0 */
706 	dev_num = slave->dev_num;
707 	slave->dev_num = 0;
708 
709 	ret = sdw_write_no_pm(slave, SDW_SCP_DEVNUMBER, dev_num);
710 	if (ret < 0) {
711 		dev_err(bus->dev, "Program device_num %d failed: %d\n",
712 			dev_num, ret);
713 		return ret;
714 	}
715 
716 	/* After xfer of msg, restore dev_num */
717 	slave->dev_num = slave->dev_num_sticky;
718 
719 	return 0;
720 }
721 
722 void sdw_extract_slave_id(struct sdw_bus *bus,
723 			  u64 addr, struct sdw_slave_id *id)
724 {
725 	dev_dbg(bus->dev, "SDW Slave Addr: %llx\n", addr);
726 
727 	id->sdw_version = SDW_VERSION(addr);
728 	id->unique_id = SDW_UNIQUE_ID(addr);
729 	id->mfg_id = SDW_MFG_ID(addr);
730 	id->part_id = SDW_PART_ID(addr);
731 	id->class_id = SDW_CLASS_ID(addr);
732 
733 	dev_dbg(bus->dev,
734 		"SDW Slave class_id 0x%02x, mfg_id 0x%04x, part_id 0x%04x, unique_id 0x%x, version 0x%x\n",
735 		id->class_id, id->mfg_id, id->part_id, id->unique_id, id->sdw_version);
736 }
737 EXPORT_SYMBOL(sdw_extract_slave_id);
738 
739 static int sdw_program_device_num(struct sdw_bus *bus, bool *programmed)
740 {
741 	u8 buf[SDW_NUM_DEV_ID_REGISTERS] = {0};
742 	struct sdw_slave *slave, *_s;
743 	struct sdw_slave_id id;
744 	struct sdw_msg msg;
745 	bool found;
746 	int count = 0, ret;
747 	u64 addr;
748 
749 	*programmed = false;
750 
751 	/* No Slave, so use raw xfer api */
752 	ret = sdw_fill_msg(&msg, NULL, SDW_SCP_DEVID_0,
753 			   SDW_NUM_DEV_ID_REGISTERS, 0, SDW_MSG_FLAG_READ, buf);
754 	if (ret < 0)
755 		return ret;
756 
757 	do {
758 		ret = sdw_transfer(bus, &msg);
759 		if (ret == -ENODATA) { /* end of device id reads */
760 			dev_dbg(bus->dev, "No more devices to enumerate\n");
761 			ret = 0;
762 			break;
763 		}
764 		if (ret < 0) {
765 			dev_err(bus->dev, "DEVID read fail:%d\n", ret);
766 			break;
767 		}
768 
769 		/*
770 		 * Construct the addr and extract. Cast the higher shift
771 		 * bits to avoid truncation due to size limit.
772 		 */
773 		addr = buf[5] | (buf[4] << 8) | (buf[3] << 16) |
774 			((u64)buf[2] << 24) | ((u64)buf[1] << 32) |
775 			((u64)buf[0] << 40);
776 
777 		sdw_extract_slave_id(bus, addr, &id);
778 
779 		found = false;
780 		/* Now compare with entries */
781 		list_for_each_entry_safe(slave, _s, &bus->slaves, node) {
782 			if (sdw_compare_devid(slave, id) == 0) {
783 				found = true;
784 
785 				/*
786 				 * To prevent skipping state-machine stages don't
787 				 * program a device until we've seen it UNATTACH.
788 				 * Must return here because no other device on #0
789 				 * can be detected until this one has been
790 				 * assigned a device ID.
791 				 */
792 				if (slave->status != SDW_SLAVE_UNATTACHED)
793 					return 0;
794 
795 				/*
796 				 * Assign a new dev_num to this Slave and
797 				 * not mark it present. It will be marked
798 				 * present after it reports ATTACHED on new
799 				 * dev_num
800 				 */
801 				ret = sdw_assign_device_num(slave);
802 				if (ret < 0) {
803 					dev_err(bus->dev,
804 						"Assign dev_num failed:%d\n",
805 						ret);
806 					return ret;
807 				}
808 
809 				*programmed = true;
810 
811 				break;
812 			}
813 		}
814 
815 		if (!found) {
816 			/* TODO: Park this device in Group 13 */
817 
818 			/*
819 			 * add Slave device even if there is no platform
820 			 * firmware description. There will be no driver probe
821 			 * but the user/integration will be able to see the
822 			 * device, enumeration status and device number in sysfs
823 			 */
824 			sdw_slave_add(bus, &id, NULL);
825 
826 			dev_err(bus->dev, "Slave Entry not found\n");
827 		}
828 
829 		count++;
830 
831 		/*
832 		 * Check till error out or retry (count) exhausts.
833 		 * Device can drop off and rejoin during enumeration
834 		 * so count till twice the bound.
835 		 */
836 
837 	} while (ret == 0 && count < (SDW_MAX_DEVICES * 2));
838 
839 	return ret;
840 }
841 
842 static void sdw_modify_slave_status(struct sdw_slave *slave,
843 				    enum sdw_slave_status status)
844 {
845 	struct sdw_bus *bus = slave->bus;
846 
847 	mutex_lock(&bus->bus_lock);
848 
849 	dev_vdbg(bus->dev,
850 		 "changing status slave %d status %d new status %d\n",
851 		 slave->dev_num, slave->status, status);
852 
853 	if (status == SDW_SLAVE_UNATTACHED) {
854 		dev_dbg(&slave->dev,
855 			"initializing enumeration and init completion for Slave %d\n",
856 			slave->dev_num);
857 
858 		init_completion(&slave->enumeration_complete);
859 		init_completion(&slave->initialization_complete);
860 
861 	} else if ((status == SDW_SLAVE_ATTACHED) &&
862 		   (slave->status == SDW_SLAVE_UNATTACHED)) {
863 		dev_dbg(&slave->dev,
864 			"signaling enumeration completion for Slave %d\n",
865 			slave->dev_num);
866 
867 		complete(&slave->enumeration_complete);
868 	}
869 	slave->status = status;
870 	mutex_unlock(&bus->bus_lock);
871 }
872 
873 static int sdw_slave_clk_stop_callback(struct sdw_slave *slave,
874 				       enum sdw_clk_stop_mode mode,
875 				       enum sdw_clk_stop_type type)
876 {
877 	int ret = 0;
878 
879 	mutex_lock(&slave->sdw_dev_lock);
880 
881 	if (slave->probed)  {
882 		struct device *dev = &slave->dev;
883 		struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
884 
885 		if (drv->ops && drv->ops->clk_stop)
886 			ret = drv->ops->clk_stop(slave, mode, type);
887 	}
888 
889 	mutex_unlock(&slave->sdw_dev_lock);
890 
891 	return ret;
892 }
893 
894 static int sdw_slave_clk_stop_prepare(struct sdw_slave *slave,
895 				      enum sdw_clk_stop_mode mode,
896 				      bool prepare)
897 {
898 	bool wake_en;
899 	u32 val = 0;
900 	int ret;
901 
902 	wake_en = slave->prop.wake_capable;
903 
904 	if (prepare) {
905 		val = SDW_SCP_SYSTEMCTRL_CLK_STP_PREP;
906 
907 		if (mode == SDW_CLK_STOP_MODE1)
908 			val |= SDW_SCP_SYSTEMCTRL_CLK_STP_MODE1;
909 
910 		if (wake_en)
911 			val |= SDW_SCP_SYSTEMCTRL_WAKE_UP_EN;
912 	} else {
913 		ret = sdw_read_no_pm(slave, SDW_SCP_SYSTEMCTRL);
914 		if (ret < 0) {
915 			if (ret != -ENODATA)
916 				dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL read failed:%d\n", ret);
917 			return ret;
918 		}
919 		val = ret;
920 		val &= ~(SDW_SCP_SYSTEMCTRL_CLK_STP_PREP);
921 	}
922 
923 	ret = sdw_write_no_pm(slave, SDW_SCP_SYSTEMCTRL, val);
924 
925 	if (ret < 0 && ret != -ENODATA)
926 		dev_err(&slave->dev, "SDW_SCP_SYSTEMCTRL write failed:%d\n", ret);
927 
928 	return ret;
929 }
930 
931 static int sdw_bus_wait_for_clk_prep_deprep(struct sdw_bus *bus, u16 dev_num)
932 {
933 	int retry = bus->clk_stop_timeout;
934 	int val;
935 
936 	do {
937 		val = sdw_bread_no_pm(bus, dev_num, SDW_SCP_STAT);
938 		if (val < 0) {
939 			if (val != -ENODATA)
940 				dev_err(bus->dev, "SDW_SCP_STAT bread failed:%d\n", val);
941 			return val;
942 		}
943 		val &= SDW_SCP_STAT_CLK_STP_NF;
944 		if (!val) {
945 			dev_dbg(bus->dev, "clock stop prep/de-prep done slave:%d\n",
946 				dev_num);
947 			return 0;
948 		}
949 
950 		usleep_range(1000, 1500);
951 		retry--;
952 	} while (retry);
953 
954 	dev_err(bus->dev, "clock stop prep/de-prep failed slave:%d\n",
955 		dev_num);
956 
957 	return -ETIMEDOUT;
958 }
959 
960 /**
961  * sdw_bus_prep_clk_stop: prepare Slave(s) for clock stop
962  *
963  * @bus: SDW bus instance
964  *
965  * Query Slave for clock stop mode and prepare for that mode.
966  */
967 int sdw_bus_prep_clk_stop(struct sdw_bus *bus)
968 {
969 	bool simple_clk_stop = true;
970 	struct sdw_slave *slave;
971 	bool is_slave = false;
972 	int ret = 0;
973 
974 	/*
975 	 * In order to save on transition time, prepare
976 	 * each Slave and then wait for all Slave(s) to be
977 	 * prepared for clock stop.
978 	 * If one of the Slave devices has lost sync and
979 	 * replies with Command Ignored/-ENODATA, we continue
980 	 * the loop
981 	 */
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 		/* Identify if Slave(s) are available on Bus */
991 		is_slave = true;
992 
993 		ret = sdw_slave_clk_stop_callback(slave,
994 						  SDW_CLK_STOP_MODE0,
995 						  SDW_CLK_PRE_PREPARE);
996 		if (ret < 0 && ret != -ENODATA) {
997 			dev_err(&slave->dev, "clock stop pre-prepare cb failed:%d\n", ret);
998 			return ret;
999 		}
1000 
1001 		/* Only prepare a Slave device if needed */
1002 		if (!slave->prop.simple_clk_stop_capable) {
1003 			simple_clk_stop = false;
1004 
1005 			ret = sdw_slave_clk_stop_prepare(slave,
1006 							 SDW_CLK_STOP_MODE0,
1007 							 true);
1008 			if (ret < 0 && ret != -ENODATA) {
1009 				dev_err(&slave->dev, "clock stop prepare failed:%d\n", ret);
1010 				return ret;
1011 			}
1012 		}
1013 	}
1014 
1015 	/* Skip remaining clock stop preparation if no Slave is attached */
1016 	if (!is_slave)
1017 		return 0;
1018 
1019 	/*
1020 	 * Don't wait for all Slaves to be ready if they follow the simple
1021 	 * state machine
1022 	 */
1023 	if (!simple_clk_stop) {
1024 		ret = sdw_bus_wait_for_clk_prep_deprep(bus,
1025 						       SDW_BROADCAST_DEV_NUM);
1026 		/*
1027 		 * if there are no Slave devices present and the reply is
1028 		 * Command_Ignored/-ENODATA, we don't need to continue with the
1029 		 * flow and can just return here. The error code is not modified
1030 		 * and its handling left as an exercise for the caller.
1031 		 */
1032 		if (ret < 0)
1033 			return ret;
1034 	}
1035 
1036 	/* Inform slaves that prep is done */
1037 	list_for_each_entry(slave, &bus->slaves, node) {
1038 		if (!slave->dev_num)
1039 			continue;
1040 
1041 		if (slave->status != SDW_SLAVE_ATTACHED &&
1042 		    slave->status != SDW_SLAVE_ALERT)
1043 			continue;
1044 
1045 		ret = sdw_slave_clk_stop_callback(slave,
1046 						  SDW_CLK_STOP_MODE0,
1047 						  SDW_CLK_POST_PREPARE);
1048 
1049 		if (ret < 0 && ret != -ENODATA) {
1050 			dev_err(&slave->dev, "clock stop post-prepare cb failed:%d\n", ret);
1051 			return ret;
1052 		}
1053 	}
1054 
1055 	return 0;
1056 }
1057 EXPORT_SYMBOL(sdw_bus_prep_clk_stop);
1058 
1059 /**
1060  * sdw_bus_clk_stop: stop bus clock
1061  *
1062  * @bus: SDW bus instance
1063  *
1064  * After preparing the Slaves for clock stop, stop the clock by broadcasting
1065  * write to SCP_CTRL register.
1066  */
1067 int sdw_bus_clk_stop(struct sdw_bus *bus)
1068 {
1069 	int ret;
1070 
1071 	/*
1072 	 * broadcast clock stop now, attached Slaves will ACK this,
1073 	 * unattached will ignore
1074 	 */
1075 	ret = sdw_bwrite_no_pm(bus, SDW_BROADCAST_DEV_NUM,
1076 			       SDW_SCP_CTRL, SDW_SCP_CTRL_CLK_STP_NOW);
1077 	if (ret < 0) {
1078 		if (ret != -ENODATA)
1079 			dev_err(bus->dev, "ClockStopNow Broadcast msg failed %d\n", ret);
1080 		return ret;
1081 	}
1082 
1083 	return 0;
1084 }
1085 EXPORT_SYMBOL(sdw_bus_clk_stop);
1086 
1087 /**
1088  * sdw_bus_exit_clk_stop: Exit clock stop mode
1089  *
1090  * @bus: SDW bus instance
1091  *
1092  * This De-prepares the Slaves by exiting Clock Stop Mode 0. For the Slaves
1093  * exiting Clock Stop Mode 1, they will be de-prepared after they enumerate
1094  * back.
1095  */
1096 int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
1097 {
1098 	bool simple_clk_stop = true;
1099 	struct sdw_slave *slave;
1100 	bool is_slave = false;
1101 	int ret;
1102 
1103 	/*
1104 	 * In order to save on transition time, de-prepare
1105 	 * each Slave and then wait for all Slave(s) to be
1106 	 * de-prepared after clock resume.
1107 	 */
1108 	list_for_each_entry(slave, &bus->slaves, node) {
1109 		if (!slave->dev_num)
1110 			continue;
1111 
1112 		if (slave->status != SDW_SLAVE_ATTACHED &&
1113 		    slave->status != SDW_SLAVE_ALERT)
1114 			continue;
1115 
1116 		/* Identify if Slave(s) are available on Bus */
1117 		is_slave = true;
1118 
1119 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1120 						  SDW_CLK_PRE_DEPREPARE);
1121 		if (ret < 0)
1122 			dev_warn(&slave->dev, "clock stop pre-deprepare cb failed:%d\n", ret);
1123 
1124 		/* Only de-prepare a Slave device if needed */
1125 		if (!slave->prop.simple_clk_stop_capable) {
1126 			simple_clk_stop = false;
1127 
1128 			ret = sdw_slave_clk_stop_prepare(slave, SDW_CLK_STOP_MODE0,
1129 							 false);
1130 
1131 			if (ret < 0)
1132 				dev_warn(&slave->dev, "clock stop deprepare failed:%d\n", ret);
1133 		}
1134 	}
1135 
1136 	/* Skip remaining clock stop de-preparation if no Slave is attached */
1137 	if (!is_slave)
1138 		return 0;
1139 
1140 	/*
1141 	 * Don't wait for all Slaves to be ready if they follow the simple
1142 	 * state machine
1143 	 */
1144 	if (!simple_clk_stop) {
1145 		ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
1146 		if (ret < 0)
1147 			dev_warn(bus->dev, "clock stop deprepare wait failed:%d\n", ret);
1148 	}
1149 
1150 	list_for_each_entry(slave, &bus->slaves, node) {
1151 		if (!slave->dev_num)
1152 			continue;
1153 
1154 		if (slave->status != SDW_SLAVE_ATTACHED &&
1155 		    slave->status != SDW_SLAVE_ALERT)
1156 			continue;
1157 
1158 		ret = sdw_slave_clk_stop_callback(slave, SDW_CLK_STOP_MODE0,
1159 						  SDW_CLK_POST_DEPREPARE);
1160 		if (ret < 0)
1161 			dev_warn(&slave->dev, "clock stop post-deprepare cb failed:%d\n", ret);
1162 	}
1163 
1164 	return 0;
1165 }
1166 EXPORT_SYMBOL(sdw_bus_exit_clk_stop);
1167 
1168 int sdw_configure_dpn_intr(struct sdw_slave *slave,
1169 			   int port, bool enable, int mask)
1170 {
1171 	u32 addr;
1172 	int ret;
1173 	u8 val = 0;
1174 
1175 	if (slave->bus->params.s_data_mode != SDW_PORT_DATA_MODE_NORMAL) {
1176 		dev_dbg(&slave->dev, "TEST FAIL interrupt %s\n",
1177 			enable ? "on" : "off");
1178 		mask |= SDW_DPN_INT_TEST_FAIL;
1179 	}
1180 
1181 	addr = SDW_DPN_INTMASK(port);
1182 
1183 	/* Set/Clear port ready interrupt mask */
1184 	if (enable) {
1185 		val |= mask;
1186 		val |= SDW_DPN_INT_PORT_READY;
1187 	} else {
1188 		val &= ~(mask);
1189 		val &= ~SDW_DPN_INT_PORT_READY;
1190 	}
1191 
1192 	ret = sdw_update_no_pm(slave, addr, (mask | SDW_DPN_INT_PORT_READY), val);
1193 	if (ret < 0)
1194 		dev_err(&slave->dev,
1195 			"SDW_DPN_INTMASK write failed:%d\n", val);
1196 
1197 	return ret;
1198 }
1199 
1200 static int sdw_slave_set_frequency(struct sdw_slave *slave)
1201 {
1202 	u32 mclk_freq = slave->bus->prop.mclk_freq;
1203 	u32 curr_freq = slave->bus->params.curr_dr_freq >> 1;
1204 	unsigned int scale;
1205 	u8 scale_index;
1206 	u8 base;
1207 	int ret;
1208 
1209 	/*
1210 	 * frequency base and scale registers are required for SDCA
1211 	 * devices. They may also be used for 1.2+/non-SDCA devices.
1212 	 * Driver can set the property, we will need a DisCo property
1213 	 * to discover this case from platform firmware.
1214 	 */
1215 	if (!slave->id.class_id && !slave->prop.clock_reg_supported)
1216 		return 0;
1217 
1218 	if (!mclk_freq) {
1219 		dev_err(&slave->dev,
1220 			"no bus MCLK, cannot set SDW_SCP_BUS_CLOCK_BASE\n");
1221 		return -EINVAL;
1222 	}
1223 
1224 	/*
1225 	 * map base frequency using Table 89 of SoundWire 1.2 spec.
1226 	 * The order of the tests just follows the specification, this
1227 	 * is not a selection between possible values or a search for
1228 	 * the best value but just a mapping.  Only one case per platform
1229 	 * is relevant.
1230 	 * Some BIOS have inconsistent values for mclk_freq but a
1231 	 * correct root so we force the mclk_freq to avoid variations.
1232 	 */
1233 	if (!(19200000 % mclk_freq)) {
1234 		mclk_freq = 19200000;
1235 		base = SDW_SCP_BASE_CLOCK_19200000_HZ;
1236 	} else if (!(24000000 % mclk_freq)) {
1237 		mclk_freq = 24000000;
1238 		base = SDW_SCP_BASE_CLOCK_24000000_HZ;
1239 	} else if (!(24576000 % mclk_freq)) {
1240 		mclk_freq = 24576000;
1241 		base = SDW_SCP_BASE_CLOCK_24576000_HZ;
1242 	} else if (!(22579200 % mclk_freq)) {
1243 		mclk_freq = 22579200;
1244 		base = SDW_SCP_BASE_CLOCK_22579200_HZ;
1245 	} else if (!(32000000 % mclk_freq)) {
1246 		mclk_freq = 32000000;
1247 		base = SDW_SCP_BASE_CLOCK_32000000_HZ;
1248 	} else {
1249 		dev_err(&slave->dev,
1250 			"Unsupported clock base, mclk %d\n",
1251 			mclk_freq);
1252 		return -EINVAL;
1253 	}
1254 
1255 	if (mclk_freq % curr_freq) {
1256 		dev_err(&slave->dev,
1257 			"mclk %d is not multiple of bus curr_freq %d\n",
1258 			mclk_freq, curr_freq);
1259 		return -EINVAL;
1260 	}
1261 
1262 	scale = mclk_freq / curr_freq;
1263 
1264 	/*
1265 	 * map scale to Table 90 of SoundWire 1.2 spec - and check
1266 	 * that the scale is a power of two and maximum 64
1267 	 */
1268 	scale_index = ilog2(scale);
1269 
1270 	if (BIT(scale_index) != scale || scale_index > 6) {
1271 		dev_err(&slave->dev,
1272 			"No match found for scale %d, bus mclk %d curr_freq %d\n",
1273 			scale, mclk_freq, curr_freq);
1274 		return -EINVAL;
1275 	}
1276 	scale_index++;
1277 
1278 	ret = sdw_write_no_pm(slave, SDW_SCP_BUS_CLOCK_BASE, base);
1279 	if (ret < 0) {
1280 		dev_err(&slave->dev,
1281 			"SDW_SCP_BUS_CLOCK_BASE write failed:%d\n", ret);
1282 		return ret;
1283 	}
1284 
1285 	/* initialize scale for both banks */
1286 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B0, scale_index);
1287 	if (ret < 0) {
1288 		dev_err(&slave->dev,
1289 			"SDW_SCP_BUSCLOCK_SCALE_B0 write failed:%d\n", ret);
1290 		return ret;
1291 	}
1292 	ret = sdw_write_no_pm(slave, SDW_SCP_BUSCLOCK_SCALE_B1, scale_index);
1293 	if (ret < 0)
1294 		dev_err(&slave->dev,
1295 			"SDW_SCP_BUSCLOCK_SCALE_B1 write failed:%d\n", ret);
1296 
1297 	dev_dbg(&slave->dev,
1298 		"Configured bus base %d, scale %d, mclk %d, curr_freq %d\n",
1299 		base, scale_index, mclk_freq, curr_freq);
1300 
1301 	return ret;
1302 }
1303 
1304 static int sdw_initialize_slave(struct sdw_slave *slave)
1305 {
1306 	struct sdw_slave_prop *prop = &slave->prop;
1307 	int status;
1308 	int ret;
1309 	u8 val;
1310 
1311 	ret = sdw_slave_set_frequency(slave);
1312 	if (ret < 0)
1313 		return ret;
1314 
1315 	if (slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH) {
1316 		/* Clear bus clash interrupt before enabling interrupt mask */
1317 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1318 		if (status < 0) {
1319 			dev_err(&slave->dev,
1320 				"SDW_SCP_INT1 (BUS_CLASH) read failed:%d\n", status);
1321 			return status;
1322 		}
1323 		if (status & SDW_SCP_INT1_BUS_CLASH) {
1324 			dev_warn(&slave->dev, "Bus clash detected before INT mask is enabled\n");
1325 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH);
1326 			if (ret < 0) {
1327 				dev_err(&slave->dev,
1328 					"SDW_SCP_INT1 (BUS_CLASH) write failed:%d\n", ret);
1329 				return ret;
1330 			}
1331 		}
1332 	}
1333 	if ((slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY) &&
1334 	    !(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY)) {
1335 		/* Clear parity interrupt before enabling interrupt mask */
1336 		status = sdw_read_no_pm(slave, SDW_SCP_INT1);
1337 		if (status < 0) {
1338 			dev_err(&slave->dev,
1339 				"SDW_SCP_INT1 (PARITY) read failed:%d\n", status);
1340 			return status;
1341 		}
1342 		if (status & SDW_SCP_INT1_PARITY) {
1343 			dev_warn(&slave->dev, "PARITY error detected before INT mask is enabled\n");
1344 			ret = sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_PARITY);
1345 			if (ret < 0) {
1346 				dev_err(&slave->dev,
1347 					"SDW_SCP_INT1 (PARITY) write failed:%d\n", ret);
1348 				return ret;
1349 			}
1350 		}
1351 	}
1352 
1353 	/*
1354 	 * Set SCP_INT1_MASK register, typically bus clash and
1355 	 * implementation-defined interrupt mask. The Parity detection
1356 	 * may not always be correct on startup so its use is
1357 	 * device-dependent, it might e.g. only be enabled in
1358 	 * steady-state after a couple of frames.
1359 	 */
1360 	val = slave->prop.scp_int1_mask;
1361 
1362 	/* Enable SCP interrupts */
1363 	ret = sdw_update_no_pm(slave, SDW_SCP_INTMASK1, val, val);
1364 	if (ret < 0) {
1365 		dev_err(&slave->dev,
1366 			"SDW_SCP_INTMASK1 write failed:%d\n", ret);
1367 		return ret;
1368 	}
1369 
1370 	/* No need to continue if DP0 is not present */
1371 	if (!slave->prop.dp0_prop)
1372 		return 0;
1373 
1374 	/* Enable DP0 interrupts */
1375 	val = prop->dp0_prop->imp_def_interrupts;
1376 	val |= SDW_DP0_INT_PORT_READY | SDW_DP0_INT_BRA_FAILURE;
1377 
1378 	ret = sdw_update_no_pm(slave, SDW_DP0_INTMASK, val, val);
1379 	if (ret < 0)
1380 		dev_err(&slave->dev,
1381 			"SDW_DP0_INTMASK read failed:%d\n", ret);
1382 	return ret;
1383 }
1384 
1385 static int sdw_handle_dp0_interrupt(struct sdw_slave *slave, u8 *slave_status)
1386 {
1387 	u8 clear, impl_int_mask;
1388 	int status, status2, ret, count = 0;
1389 
1390 	status = sdw_read_no_pm(slave, SDW_DP0_INT);
1391 	if (status < 0) {
1392 		dev_err(&slave->dev,
1393 			"SDW_DP0_INT read failed:%d\n", status);
1394 		return status;
1395 	}
1396 
1397 	do {
1398 		clear = status & ~SDW_DP0_INTERRUPTS;
1399 
1400 		if (status & SDW_DP0_INT_TEST_FAIL) {
1401 			dev_err(&slave->dev, "Test fail for port 0\n");
1402 			clear |= SDW_DP0_INT_TEST_FAIL;
1403 		}
1404 
1405 		/*
1406 		 * Assumption: PORT_READY interrupt will be received only for
1407 		 * ports implementing Channel Prepare state machine (CP_SM)
1408 		 */
1409 
1410 		if (status & SDW_DP0_INT_PORT_READY) {
1411 			complete(&slave->port_ready[0]);
1412 			clear |= SDW_DP0_INT_PORT_READY;
1413 		}
1414 
1415 		if (status & SDW_DP0_INT_BRA_FAILURE) {
1416 			dev_err(&slave->dev, "BRA failed\n");
1417 			clear |= SDW_DP0_INT_BRA_FAILURE;
1418 		}
1419 
1420 		impl_int_mask = SDW_DP0_INT_IMPDEF1 |
1421 			SDW_DP0_INT_IMPDEF2 | SDW_DP0_INT_IMPDEF3;
1422 
1423 		if (status & impl_int_mask) {
1424 			clear |= impl_int_mask;
1425 			*slave_status = clear;
1426 		}
1427 
1428 		/* clear the interrupts but don't touch reserved and SDCA_CASCADE fields */
1429 		ret = sdw_write_no_pm(slave, SDW_DP0_INT, clear);
1430 		if (ret < 0) {
1431 			dev_err(&slave->dev,
1432 				"SDW_DP0_INT write failed:%d\n", ret);
1433 			return ret;
1434 		}
1435 
1436 		/* Read DP0 interrupt again */
1437 		status2 = sdw_read_no_pm(slave, SDW_DP0_INT);
1438 		if (status2 < 0) {
1439 			dev_err(&slave->dev,
1440 				"SDW_DP0_INT read failed:%d\n", status2);
1441 			return status2;
1442 		}
1443 		/* filter to limit loop to interrupts identified in the first status read */
1444 		status &= status2;
1445 
1446 		count++;
1447 
1448 		/* we can get alerts while processing so keep retrying */
1449 	} while ((status & SDW_DP0_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1450 
1451 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1452 		dev_warn(&slave->dev, "Reached MAX_RETRY on DP0 read\n");
1453 
1454 	return ret;
1455 }
1456 
1457 static int sdw_handle_port_interrupt(struct sdw_slave *slave,
1458 				     int port, u8 *slave_status)
1459 {
1460 	u8 clear, impl_int_mask;
1461 	int status, status2, ret, count = 0;
1462 	u32 addr;
1463 
1464 	if (port == 0)
1465 		return sdw_handle_dp0_interrupt(slave, slave_status);
1466 
1467 	addr = SDW_DPN_INT(port);
1468 	status = sdw_read_no_pm(slave, addr);
1469 	if (status < 0) {
1470 		dev_err(&slave->dev,
1471 			"SDW_DPN_INT read failed:%d\n", status);
1472 
1473 		return status;
1474 	}
1475 
1476 	do {
1477 		clear = status & ~SDW_DPN_INTERRUPTS;
1478 
1479 		if (status & SDW_DPN_INT_TEST_FAIL) {
1480 			dev_err(&slave->dev, "Test fail for port:%d\n", port);
1481 			clear |= SDW_DPN_INT_TEST_FAIL;
1482 		}
1483 
1484 		/*
1485 		 * Assumption: PORT_READY interrupt will be received only
1486 		 * for ports implementing CP_SM.
1487 		 */
1488 		if (status & SDW_DPN_INT_PORT_READY) {
1489 			complete(&slave->port_ready[port]);
1490 			clear |= SDW_DPN_INT_PORT_READY;
1491 		}
1492 
1493 		impl_int_mask = SDW_DPN_INT_IMPDEF1 |
1494 			SDW_DPN_INT_IMPDEF2 | SDW_DPN_INT_IMPDEF3;
1495 
1496 		if (status & impl_int_mask) {
1497 			clear |= impl_int_mask;
1498 			*slave_status = clear;
1499 		}
1500 
1501 		/* clear the interrupt but don't touch reserved fields */
1502 		ret = sdw_write_no_pm(slave, addr, clear);
1503 		if (ret < 0) {
1504 			dev_err(&slave->dev,
1505 				"SDW_DPN_INT write failed:%d\n", ret);
1506 			return ret;
1507 		}
1508 
1509 		/* Read DPN interrupt again */
1510 		status2 = sdw_read_no_pm(slave, addr);
1511 		if (status2 < 0) {
1512 			dev_err(&slave->dev,
1513 				"SDW_DPN_INT read failed:%d\n", status2);
1514 			return status2;
1515 		}
1516 		/* filter to limit loop to interrupts identified in the first status read */
1517 		status &= status2;
1518 
1519 		count++;
1520 
1521 		/* we can get alerts while processing so keep retrying */
1522 	} while ((status & SDW_DPN_INTERRUPTS) && (count < SDW_READ_INTR_CLEAR_RETRY));
1523 
1524 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1525 		dev_warn(&slave->dev, "Reached MAX_RETRY on port read");
1526 
1527 	return ret;
1528 }
1529 
1530 static int sdw_handle_slave_alerts(struct sdw_slave *slave)
1531 {
1532 	struct sdw_slave_intr_status slave_intr;
1533 	u8 clear = 0, bit, port_status[15] = {0};
1534 	int port_num, stat, ret, count = 0;
1535 	unsigned long port;
1536 	bool slave_notify;
1537 	u8 sdca_cascade = 0;
1538 	u8 buf, buf2[2], _buf, _buf2[2];
1539 	bool parity_check;
1540 	bool parity_quirk;
1541 
1542 	sdw_modify_slave_status(slave, SDW_SLAVE_ALERT);
1543 
1544 	ret = pm_runtime_resume_and_get(&slave->dev);
1545 	if (ret < 0 && ret != -EACCES) {
1546 		dev_err(&slave->dev, "Failed to resume device: %d\n", ret);
1547 		return ret;
1548 	}
1549 
1550 	/* Read Intstat 1, Intstat 2 and Intstat 3 registers */
1551 	ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1552 	if (ret < 0) {
1553 		dev_err(&slave->dev,
1554 			"SDW_SCP_INT1 read failed:%d\n", ret);
1555 		goto io_err;
1556 	}
1557 	buf = ret;
1558 
1559 	ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, buf2);
1560 	if (ret < 0) {
1561 		dev_err(&slave->dev,
1562 			"SDW_SCP_INT2/3 read failed:%d\n", ret);
1563 		goto io_err;
1564 	}
1565 
1566 	if (slave->id.class_id) {
1567 		ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1568 		if (ret < 0) {
1569 			dev_err(&slave->dev,
1570 				"SDW_DP0_INT read failed:%d\n", ret);
1571 			goto io_err;
1572 		}
1573 		sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1574 	}
1575 
1576 	do {
1577 		slave_notify = false;
1578 
1579 		/*
1580 		 * Check parity, bus clash and Slave (impl defined)
1581 		 * interrupt
1582 		 */
1583 		if (buf & SDW_SCP_INT1_PARITY) {
1584 			parity_check = slave->prop.scp_int1_mask & SDW_SCP_INT1_PARITY;
1585 			parity_quirk = !slave->first_interrupt_done &&
1586 				(slave->prop.quirks & SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY);
1587 
1588 			if (parity_check && !parity_quirk)
1589 				dev_err(&slave->dev, "Parity error detected\n");
1590 			clear |= SDW_SCP_INT1_PARITY;
1591 		}
1592 
1593 		if (buf & SDW_SCP_INT1_BUS_CLASH) {
1594 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_BUS_CLASH)
1595 				dev_err(&slave->dev, "Bus clash detected\n");
1596 			clear |= SDW_SCP_INT1_BUS_CLASH;
1597 		}
1598 
1599 		/*
1600 		 * When bus clash or parity errors are detected, such errors
1601 		 * are unlikely to be recoverable errors.
1602 		 * TODO: In such scenario, reset bus. Make this configurable
1603 		 * via sysfs property with bus reset being the default.
1604 		 */
1605 
1606 		if (buf & SDW_SCP_INT1_IMPL_DEF) {
1607 			if (slave->prop.scp_int1_mask & SDW_SCP_INT1_IMPL_DEF) {
1608 				dev_dbg(&slave->dev, "Slave impl defined interrupt\n");
1609 				slave_notify = true;
1610 			}
1611 			clear |= SDW_SCP_INT1_IMPL_DEF;
1612 		}
1613 
1614 		/* the SDCA interrupts are cleared in the codec driver .interrupt_callback() */
1615 		if (sdca_cascade)
1616 			slave_notify = true;
1617 
1618 		/* Check port 0 - 3 interrupts */
1619 		port = buf & SDW_SCP_INT1_PORT0_3;
1620 
1621 		/* To get port number corresponding to bits, shift it */
1622 		port = FIELD_GET(SDW_SCP_INT1_PORT0_3, port);
1623 		for_each_set_bit(bit, &port, 8) {
1624 			sdw_handle_port_interrupt(slave, bit,
1625 						  &port_status[bit]);
1626 		}
1627 
1628 		/* Check if cascade 2 interrupt is present */
1629 		if (buf & SDW_SCP_INT1_SCP2_CASCADE) {
1630 			port = buf2[0] & SDW_SCP_INTSTAT2_PORT4_10;
1631 			for_each_set_bit(bit, &port, 8) {
1632 				/* scp2 ports start from 4 */
1633 				port_num = bit + 4;
1634 				sdw_handle_port_interrupt(slave,
1635 						port_num,
1636 						&port_status[port_num]);
1637 			}
1638 		}
1639 
1640 		/* now check last cascade */
1641 		if (buf2[0] & SDW_SCP_INTSTAT2_SCP3_CASCADE) {
1642 			port = buf2[1] & SDW_SCP_INTSTAT3_PORT11_14;
1643 			for_each_set_bit(bit, &port, 8) {
1644 				/* scp3 ports start from 11 */
1645 				port_num = bit + 11;
1646 				sdw_handle_port_interrupt(slave,
1647 						port_num,
1648 						&port_status[port_num]);
1649 			}
1650 		}
1651 
1652 		/* Update the Slave driver */
1653 		if (slave_notify) {
1654 			mutex_lock(&slave->sdw_dev_lock);
1655 
1656 			if (slave->probed) {
1657 				struct device *dev = &slave->dev;
1658 				struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
1659 
1660 				if (drv->ops && drv->ops->interrupt_callback) {
1661 					slave_intr.sdca_cascade = sdca_cascade;
1662 					slave_intr.control_port = clear;
1663 					memcpy(slave_intr.port, &port_status,
1664 					       sizeof(slave_intr.port));
1665 
1666 					drv->ops->interrupt_callback(slave, &slave_intr);
1667 				}
1668 			}
1669 
1670 			mutex_unlock(&slave->sdw_dev_lock);
1671 		}
1672 
1673 		/* Ack interrupt */
1674 		ret = sdw_write_no_pm(slave, SDW_SCP_INT1, clear);
1675 		if (ret < 0) {
1676 			dev_err(&slave->dev,
1677 				"SDW_SCP_INT1 write failed:%d\n", ret);
1678 			goto io_err;
1679 		}
1680 
1681 		/* at this point all initial interrupt sources were handled */
1682 		slave->first_interrupt_done = true;
1683 
1684 		/*
1685 		 * Read status again to ensure no new interrupts arrived
1686 		 * while servicing interrupts.
1687 		 */
1688 		ret = sdw_read_no_pm(slave, SDW_SCP_INT1);
1689 		if (ret < 0) {
1690 			dev_err(&slave->dev,
1691 				"SDW_SCP_INT1 recheck read failed:%d\n", ret);
1692 			goto io_err;
1693 		}
1694 		_buf = ret;
1695 
1696 		ret = sdw_nread_no_pm(slave, SDW_SCP_INTSTAT2, 2, _buf2);
1697 		if (ret < 0) {
1698 			dev_err(&slave->dev,
1699 				"SDW_SCP_INT2/3 recheck read failed:%d\n", ret);
1700 			goto io_err;
1701 		}
1702 
1703 		if (slave->id.class_id) {
1704 			ret = sdw_read_no_pm(slave, SDW_DP0_INT);
1705 			if (ret < 0) {
1706 				dev_err(&slave->dev,
1707 					"SDW_DP0_INT recheck read failed:%d\n", ret);
1708 				goto io_err;
1709 			}
1710 			sdca_cascade = ret & SDW_DP0_SDCA_CASCADE;
1711 		}
1712 
1713 		/*
1714 		 * Make sure no interrupts are pending, but filter to limit loop
1715 		 * to interrupts identified in the first status read
1716 		 */
1717 		buf &= _buf;
1718 		buf2[0] &= _buf2[0];
1719 		buf2[1] &= _buf2[1];
1720 		stat = buf || buf2[0] || buf2[1] || sdca_cascade;
1721 
1722 		/*
1723 		 * Exit loop if Slave is continuously in ALERT state even
1724 		 * after servicing the interrupt multiple times.
1725 		 */
1726 		count++;
1727 
1728 		/* we can get alerts while processing so keep retrying */
1729 	} while (stat != 0 && count < SDW_READ_INTR_CLEAR_RETRY);
1730 
1731 	if (count == SDW_READ_INTR_CLEAR_RETRY)
1732 		dev_warn(&slave->dev, "Reached MAX_RETRY on alert read\n");
1733 
1734 io_err:
1735 	pm_runtime_mark_last_busy(&slave->dev);
1736 	pm_runtime_put_autosuspend(&slave->dev);
1737 
1738 	return ret;
1739 }
1740 
1741 static int sdw_update_slave_status(struct sdw_slave *slave,
1742 				   enum sdw_slave_status status)
1743 {
1744 	int ret = 0;
1745 
1746 	mutex_lock(&slave->sdw_dev_lock);
1747 
1748 	if (slave->probed) {
1749 		struct device *dev = &slave->dev;
1750 		struct sdw_driver *drv = drv_to_sdw_driver(dev->driver);
1751 
1752 		if (drv->ops && drv->ops->update_status)
1753 			ret = drv->ops->update_status(slave, status);
1754 	}
1755 
1756 	mutex_unlock(&slave->sdw_dev_lock);
1757 
1758 	return ret;
1759 }
1760 
1761 /**
1762  * sdw_handle_slave_status() - Handle Slave status
1763  * @bus: SDW bus instance
1764  * @status: Status for all Slave(s)
1765  */
1766 int sdw_handle_slave_status(struct sdw_bus *bus,
1767 			    enum sdw_slave_status status[])
1768 {
1769 	enum sdw_slave_status prev_status;
1770 	struct sdw_slave *slave;
1771 	bool attached_initializing, id_programmed;
1772 	int i, ret = 0;
1773 
1774 	/* first check if any Slaves fell off the bus */
1775 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1776 		mutex_lock(&bus->bus_lock);
1777 		if (test_bit(i, bus->assigned) == false) {
1778 			mutex_unlock(&bus->bus_lock);
1779 			continue;
1780 		}
1781 		mutex_unlock(&bus->bus_lock);
1782 
1783 		slave = sdw_get_slave(bus, i);
1784 		if (!slave)
1785 			continue;
1786 
1787 		if (status[i] == SDW_SLAVE_UNATTACHED &&
1788 		    slave->status != SDW_SLAVE_UNATTACHED) {
1789 			dev_warn(&slave->dev, "Slave %d state check1: UNATTACHED, status was %d\n",
1790 				 i, slave->status);
1791 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1792 
1793 			/* Ensure driver knows that peripheral unattached */
1794 			ret = sdw_update_slave_status(slave, status[i]);
1795 			if (ret < 0)
1796 				dev_warn(&slave->dev, "Update Slave status failed:%d\n", ret);
1797 		}
1798 	}
1799 
1800 	if (status[0] == SDW_SLAVE_ATTACHED) {
1801 		dev_dbg(bus->dev, "Slave attached, programming device number\n");
1802 
1803 		/*
1804 		 * Programming a device number will have side effects,
1805 		 * so we deal with other devices at a later time.
1806 		 * This relies on those devices reporting ATTACHED, which will
1807 		 * trigger another call to this function. This will only
1808 		 * happen if at least one device ID was programmed.
1809 		 * Error returns from sdw_program_device_num() are currently
1810 		 * ignored because there's no useful recovery that can be done.
1811 		 * Returning the error here could result in the current status
1812 		 * of other devices not being handled, because if no device IDs
1813 		 * were programmed there's nothing to guarantee a status change
1814 		 * to trigger another call to this function.
1815 		 */
1816 		sdw_program_device_num(bus, &id_programmed);
1817 		if (id_programmed)
1818 			return 0;
1819 	}
1820 
1821 	/* Continue to check other slave statuses */
1822 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1823 		mutex_lock(&bus->bus_lock);
1824 		if (test_bit(i, bus->assigned) == false) {
1825 			mutex_unlock(&bus->bus_lock);
1826 			continue;
1827 		}
1828 		mutex_unlock(&bus->bus_lock);
1829 
1830 		slave = sdw_get_slave(bus, i);
1831 		if (!slave)
1832 			continue;
1833 
1834 		attached_initializing = false;
1835 
1836 		switch (status[i]) {
1837 		case SDW_SLAVE_UNATTACHED:
1838 			if (slave->status == SDW_SLAVE_UNATTACHED)
1839 				break;
1840 
1841 			dev_warn(&slave->dev, "Slave %d state check2: UNATTACHED, status was %d\n",
1842 				 i, slave->status);
1843 
1844 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1845 			break;
1846 
1847 		case SDW_SLAVE_ALERT:
1848 			ret = sdw_handle_slave_alerts(slave);
1849 			if (ret < 0)
1850 				dev_err(&slave->dev,
1851 					"Slave %d alert handling failed: %d\n",
1852 					i, ret);
1853 			break;
1854 
1855 		case SDW_SLAVE_ATTACHED:
1856 			if (slave->status == SDW_SLAVE_ATTACHED)
1857 				break;
1858 
1859 			prev_status = slave->status;
1860 			sdw_modify_slave_status(slave, SDW_SLAVE_ATTACHED);
1861 
1862 			if (prev_status == SDW_SLAVE_ALERT)
1863 				break;
1864 
1865 			attached_initializing = true;
1866 
1867 			ret = sdw_initialize_slave(slave);
1868 			if (ret < 0)
1869 				dev_err(&slave->dev,
1870 					"Slave %d initialization failed: %d\n",
1871 					i, ret);
1872 
1873 			break;
1874 
1875 		default:
1876 			dev_err(&slave->dev, "Invalid slave %d status:%d\n",
1877 				i, status[i]);
1878 			break;
1879 		}
1880 
1881 		ret = sdw_update_slave_status(slave, status[i]);
1882 		if (ret < 0)
1883 			dev_err(&slave->dev,
1884 				"Update Slave status failed:%d\n", ret);
1885 		if (attached_initializing) {
1886 			dev_dbg(&slave->dev,
1887 				"signaling initialization completion for Slave %d\n",
1888 				slave->dev_num);
1889 
1890 			complete(&slave->initialization_complete);
1891 
1892 			/*
1893 			 * If the manager became pm_runtime active, the peripherals will be
1894 			 * restarted and attach, but their pm_runtime status may remain
1895 			 * suspended. If the 'update_slave_status' callback initiates
1896 			 * any sort of deferred processing, this processing would not be
1897 			 * cancelled on pm_runtime suspend.
1898 			 * To avoid such zombie states, we queue a request to resume.
1899 			 * This would be a no-op in case the peripheral was being resumed
1900 			 * by e.g. the ALSA/ASoC framework.
1901 			 */
1902 			pm_request_resume(&slave->dev);
1903 		}
1904 	}
1905 
1906 	return ret;
1907 }
1908 EXPORT_SYMBOL(sdw_handle_slave_status);
1909 
1910 void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
1911 {
1912 	struct sdw_slave *slave;
1913 	int i;
1914 
1915 	/* Check all non-zero devices */
1916 	for (i = 1; i <= SDW_MAX_DEVICES; i++) {
1917 		mutex_lock(&bus->bus_lock);
1918 		if (test_bit(i, bus->assigned) == false) {
1919 			mutex_unlock(&bus->bus_lock);
1920 			continue;
1921 		}
1922 		mutex_unlock(&bus->bus_lock);
1923 
1924 		slave = sdw_get_slave(bus, i);
1925 		if (!slave)
1926 			continue;
1927 
1928 		if (slave->status != SDW_SLAVE_UNATTACHED) {
1929 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
1930 			slave->first_interrupt_done = false;
1931 			sdw_update_slave_status(slave, SDW_SLAVE_UNATTACHED);
1932 		}
1933 
1934 		/* keep track of request, used in pm_runtime resume */
1935 		slave->unattach_request = request;
1936 	}
1937 }
1938 EXPORT_SYMBOL(sdw_clear_slave_status);
1939