1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2 // Copyright(c) 2015-22 Intel Corporation.
3 
4 /*
5  * Soundwire Intel Manager Driver
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/debugfs.h>
10 #include <linux/delay.h>
11 #include <linux/module.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/auxiliary_bus.h>
15 #include <sound/pcm_params.h>
16 #include <linux/pm_runtime.h>
17 #include <sound/soc.h>
18 #include <linux/soundwire/sdw_registers.h>
19 #include <linux/soundwire/sdw.h>
20 #include <linux/soundwire/sdw_intel.h>
21 #include "cadence_master.h"
22 #include "bus.h"
23 #include "intel.h"
24 #include "intel_auxdevice.h"
25 
26 #define INTEL_MASTER_SUSPEND_DELAY_MS	3000
27 
28 /*
29  * debug/config flags for the Intel SoundWire Master.
30  *
31  * Since we may have multiple masters active, we can have up to 8
32  * flags reused in each byte, with master0 using the ls-byte, etc.
33  */
34 
35 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME		BIT(0)
36 #define SDW_INTEL_MASTER_DISABLE_CLOCK_STOP		BIT(1)
37 #define SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE	BIT(2)
38 #define SDW_INTEL_MASTER_DISABLE_MULTI_LINK		BIT(3)
39 
40 static int md_flags;
41 module_param_named(sdw_md_flags, md_flags, int, 0444);
42 MODULE_PARM_DESC(sdw_md_flags, "SoundWire Intel Master device flags (0x0 all off)");
43 
44 struct wake_capable_part {
45 	const u16 mfg_id;
46 	const u16 part_id;
47 };
48 
49 static struct wake_capable_part wake_capable_list[] = {
50 	{0x025d, 0x5682},
51 	{0x025d, 0x700},
52 	{0x025d, 0x711},
53 	{0x025d, 0x1712},
54 	{0x025d, 0x1713},
55 	{0x025d, 0x1716},
56 	{0x025d, 0x1717},
57 	{0x025d, 0x712},
58 	{0x025d, 0x713},
59 	{0x025d, 0x714},
60 	{0x025d, 0x715},
61 	{0x025d, 0x716},
62 	{0x025d, 0x717},
63 	{0x025d, 0x722},
64 };
65 
66 static bool is_wake_capable(struct sdw_slave *slave)
67 {
68 	int i;
69 
70 	for (i = 0; i < ARRAY_SIZE(wake_capable_list); i++)
71 		if (slave->id.part_id == wake_capable_list[i].part_id &&
72 		    slave->id.mfg_id == wake_capable_list[i].mfg_id)
73 			return true;
74 	return false;
75 }
76 
77 static int generic_pre_bank_switch(struct sdw_bus *bus)
78 {
79 	struct sdw_cdns *cdns = bus_to_cdns(bus);
80 	struct sdw_intel *sdw = cdns_to_intel(cdns);
81 
82 	return sdw->link_res->hw_ops->pre_bank_switch(sdw);
83 }
84 
85 static int generic_post_bank_switch(struct sdw_bus *bus)
86 {
87 	struct sdw_cdns *cdns = bus_to_cdns(bus);
88 	struct sdw_intel *sdw = cdns_to_intel(cdns);
89 
90 	return sdw->link_res->hw_ops->post_bank_switch(sdw);
91 }
92 
93 static void generic_new_peripheral_assigned(struct sdw_bus *bus,
94 					    struct sdw_slave *slave,
95 					    int dev_num)
96 {
97 	struct sdw_cdns *cdns = bus_to_cdns(bus);
98 	struct sdw_intel *sdw = cdns_to_intel(cdns);
99 	int dev_num_min;
100 	int dev_num_max;
101 	bool wake_capable = slave->prop.wake_capable || is_wake_capable(slave);
102 
103 	if (wake_capable) {
104 		dev_num_min = SDW_INTEL_DEV_NUM_IDA_MIN;
105 		dev_num_max = SDW_MAX_DEVICES;
106 	} else {
107 		dev_num_min = 1;
108 		dev_num_max = SDW_INTEL_DEV_NUM_IDA_MIN - 1;
109 	}
110 
111 	/* paranoia check, this should never happen */
112 	if (dev_num < dev_num_min || dev_num > dev_num_max)  {
113 		dev_err(bus->dev, "%s: invalid dev_num %d, wake supported %d\n",
114 			__func__, dev_num, slave->prop.wake_capable);
115 		return;
116 	}
117 
118 	if (sdw->link_res->hw_ops->program_sdi && wake_capable)
119 		sdw->link_res->hw_ops->program_sdi(sdw, dev_num);
120 }
121 
122 static int sdw_master_read_intel_prop(struct sdw_bus *bus)
123 {
124 	struct sdw_master_prop *prop = &bus->prop;
125 	struct fwnode_handle *link;
126 	char name[32];
127 	u32 quirk_mask;
128 
129 	/* Find master handle */
130 	snprintf(name, sizeof(name),
131 		 "mipi-sdw-link-%d-subproperties", bus->link_id);
132 
133 	link = device_get_named_child_node(bus->dev, name);
134 	if (!link) {
135 		dev_err(bus->dev, "Master node %s not found\n", name);
136 		return -EIO;
137 	}
138 
139 	fwnode_property_read_u32(link,
140 				 "intel-sdw-ip-clock",
141 				 &prop->mclk_freq);
142 
143 	/* the values reported by BIOS are the 2x clock, not the bus clock */
144 	prop->mclk_freq /= 2;
145 
146 	fwnode_property_read_u32(link,
147 				 "intel-quirk-mask",
148 				 &quirk_mask);
149 
150 	if (quirk_mask & SDW_INTEL_QUIRK_MASK_BUS_DISABLE)
151 		prop->hw_disabled = true;
152 
153 	prop->quirks = SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH |
154 		SDW_MASTER_QUIRKS_CLEAR_INITIAL_PARITY;
155 
156 	return 0;
157 }
158 
159 static int intel_prop_read(struct sdw_bus *bus)
160 {
161 	/* Initialize with default handler to read all DisCo properties */
162 	sdw_master_read_prop(bus);
163 
164 	/* read Intel-specific properties */
165 	sdw_master_read_intel_prop(bus);
166 
167 	return 0;
168 }
169 
170 static DEFINE_IDA(intel_peripheral_ida);
171 
172 static int intel_get_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
173 {
174 	int bit;
175 
176 	if (slave->prop.wake_capable || is_wake_capable(slave))
177 		return ida_alloc_range(&intel_peripheral_ida,
178 				       SDW_INTEL_DEV_NUM_IDA_MIN, SDW_MAX_DEVICES,
179 				       GFP_KERNEL);
180 
181 	bit = find_first_zero_bit(slave->bus->assigned, SDW_MAX_DEVICES);
182 	if (bit == SDW_MAX_DEVICES)
183 		return -ENODEV;
184 
185 	return bit;
186 }
187 
188 static void intel_put_device_num_ida(struct sdw_bus *bus, struct sdw_slave *slave)
189 {
190 	if (slave->prop.wake_capable || is_wake_capable(slave))
191 		ida_free(&intel_peripheral_ida, slave->dev_num);
192 }
193 
194 static struct sdw_master_ops sdw_intel_ops = {
195 	.read_prop = intel_prop_read,
196 	.override_adr = sdw_dmi_override_adr,
197 	.xfer_msg = cdns_xfer_msg,
198 	.xfer_msg_defer = cdns_xfer_msg_defer,
199 	.set_bus_conf = cdns_bus_conf,
200 	.pre_bank_switch = generic_pre_bank_switch,
201 	.post_bank_switch = generic_post_bank_switch,
202 	.read_ping_status = cdns_read_ping_status,
203 	.get_device_num =  intel_get_device_num_ida,
204 	.put_device_num = intel_put_device_num_ida,
205 	.new_peripheral_assigned = generic_new_peripheral_assigned,
206 };
207 
208 /*
209  * probe and init (aux_dev_id argument is required by function prototype but not used)
210  */
211 static int intel_link_probe(struct auxiliary_device *auxdev,
212 			    const struct auxiliary_device_id *aux_dev_id)
213 
214 {
215 	struct device *dev = &auxdev->dev;
216 	struct sdw_intel_link_dev *ldev = auxiliary_dev_to_sdw_intel_link_dev(auxdev);
217 	struct sdw_intel *sdw;
218 	struct sdw_cdns *cdns;
219 	struct sdw_bus *bus;
220 	int ret;
221 
222 	sdw = devm_kzalloc(dev, sizeof(*sdw), GFP_KERNEL);
223 	if (!sdw)
224 		return -ENOMEM;
225 
226 	cdns = &sdw->cdns;
227 	bus = &cdns->bus;
228 
229 	sdw->instance = auxdev->id;
230 	sdw->link_res = &ldev->link_res;
231 	cdns->dev = dev;
232 	cdns->registers = sdw->link_res->registers;
233 	cdns->ip_offset = sdw->link_res->ip_offset;
234 	cdns->instance = sdw->instance;
235 	cdns->msg_count = 0;
236 
237 	bus->link_id = auxdev->id;
238 	bus->clk_stop_timeout = 1;
239 
240 	sdw_cdns_probe(cdns);
241 
242 	/* Set ops */
243 	bus->ops = &sdw_intel_ops;
244 
245 	/* set driver data, accessed by snd_soc_dai_get_drvdata() */
246 	auxiliary_set_drvdata(auxdev, cdns);
247 
248 	/* use generic bandwidth allocation algorithm */
249 	sdw->cdns.bus.compute_params = sdw_compute_params;
250 
251 	/* avoid resuming from pm_runtime suspend if it's not required */
252 	dev_pm_set_driver_flags(dev, DPM_FLAG_SMART_SUSPEND);
253 
254 	ret = sdw_bus_master_add(bus, dev, dev->fwnode);
255 	if (ret) {
256 		dev_err(dev, "sdw_bus_master_add fail: %d\n", ret);
257 		return ret;
258 	}
259 
260 	if (bus->prop.hw_disabled)
261 		dev_info(dev,
262 			 "SoundWire master %d is disabled, will be ignored\n",
263 			 bus->link_id);
264 	/*
265 	 * Ignore BIOS err_threshold, it's a really bad idea when dealing
266 	 * with multiple hardware synchronized links
267 	 */
268 	bus->prop.err_threshold = 0;
269 
270 	return 0;
271 }
272 
273 int intel_link_startup(struct auxiliary_device *auxdev)
274 {
275 	struct device *dev = &auxdev->dev;
276 	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
277 	struct sdw_intel *sdw = cdns_to_intel(cdns);
278 	struct sdw_bus *bus = &cdns->bus;
279 	int link_flags;
280 	bool multi_link;
281 	u32 clock_stop_quirks;
282 	int ret;
283 
284 	if (bus->prop.hw_disabled) {
285 		dev_info(dev,
286 			 "SoundWire master %d is disabled, ignoring\n",
287 			 sdw->instance);
288 		return 0;
289 	}
290 
291 	link_flags = md_flags >> (bus->link_id * 8);
292 	multi_link = !(link_flags & SDW_INTEL_MASTER_DISABLE_MULTI_LINK);
293 	if (!multi_link) {
294 		dev_dbg(dev, "Multi-link is disabled\n");
295 	} else {
296 		/*
297 		 * hardware-based synchronization is required regardless
298 		 * of the number of segments used by a stream: SSP-based
299 		 * synchronization is gated by gsync when the multi-master
300 		 * mode is set.
301 		 */
302 		bus->hw_sync_min_links = 1;
303 	}
304 	bus->multi_link = multi_link;
305 
306 	/* Initialize shim, controller */
307 	ret = sdw_intel_link_power_up(sdw);
308 	if (ret)
309 		goto err_init;
310 
311 	/* Register DAIs */
312 	ret = sdw_intel_register_dai(sdw);
313 	if (ret) {
314 		dev_err(dev, "DAI registration failed: %d\n", ret);
315 		goto err_power_up;
316 	}
317 
318 	sdw_intel_debugfs_init(sdw);
319 
320 	/* Enable runtime PM */
321 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME)) {
322 		pm_runtime_set_autosuspend_delay(dev,
323 						 INTEL_MASTER_SUSPEND_DELAY_MS);
324 		pm_runtime_use_autosuspend(dev);
325 		pm_runtime_mark_last_busy(dev);
326 
327 		pm_runtime_set_active(dev);
328 		pm_runtime_enable(dev);
329 
330 		pm_runtime_resume(bus->dev);
331 	}
332 
333 	/* start bus */
334 	ret = sdw_intel_start_bus(sdw);
335 	if (ret) {
336 		dev_err(dev, "bus start failed: %d\n", ret);
337 		goto err_pm_runtime;
338 	}
339 
340 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
341 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_NOT_ALLOWED) {
342 		/*
343 		 * To keep the clock running we need to prevent
344 		 * pm_runtime suspend from happening by increasing the
345 		 * reference count.
346 		 * This quirk is specified by the parent PCI device in
347 		 * case of specific latency requirements. It will have
348 		 * no effect if pm_runtime is disabled by the user via
349 		 * a module parameter for testing purposes.
350 		 */
351 		pm_runtime_get_noresume(dev);
352 	}
353 
354 	/*
355 	 * The runtime PM status of Slave devices is "Unsupported"
356 	 * until they report as ATTACHED. If they don't, e.g. because
357 	 * there are no Slave devices populated or if the power-on is
358 	 * delayed or dependent on a power switch, the Master will
359 	 * remain active and prevent its parent from suspending.
360 	 *
361 	 * Conditionally force the pm_runtime core to re-evaluate the
362 	 * Master status in the absence of any Slave activity. A quirk
363 	 * is provided to e.g. deal with Slaves that may be powered on
364 	 * with a delay. A more complete solution would require the
365 	 * definition of Master properties.
366 	 */
367 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE)) {
368 		pm_runtime_mark_last_busy(bus->dev);
369 		pm_runtime_mark_last_busy(dev);
370 		pm_runtime_idle(dev);
371 	}
372 
373 	sdw->startup_done = true;
374 	return 0;
375 
376 err_pm_runtime:
377 	if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME))
378 		pm_runtime_disable(dev);
379 err_power_up:
380 	sdw_intel_link_power_down(sdw);
381 err_init:
382 	return ret;
383 }
384 
385 static void intel_link_remove(struct auxiliary_device *auxdev)
386 {
387 	struct sdw_cdns *cdns = auxiliary_get_drvdata(auxdev);
388 	struct sdw_intel *sdw = cdns_to_intel(cdns);
389 	struct sdw_bus *bus = &cdns->bus;
390 
391 	/*
392 	 * Since pm_runtime is already disabled, we don't decrease
393 	 * the refcount when the clock_stop_quirk is
394 	 * SDW_INTEL_CLK_STOP_NOT_ALLOWED
395 	 */
396 	if (!bus->prop.hw_disabled) {
397 		sdw_intel_debugfs_exit(sdw);
398 		sdw_cdns_enable_interrupt(cdns, false);
399 	}
400 	sdw_bus_master_delete(bus);
401 }
402 
403 int intel_link_process_wakeen_event(struct auxiliary_device *auxdev)
404 {
405 	struct device *dev = &auxdev->dev;
406 	struct sdw_intel *sdw;
407 	struct sdw_bus *bus;
408 
409 	sdw = auxiliary_get_drvdata(auxdev);
410 	bus = &sdw->cdns.bus;
411 
412 	if (bus->prop.hw_disabled || !sdw->startup_done) {
413 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
414 			bus->link_id);
415 		return 0;
416 	}
417 
418 	if (!sdw_intel_shim_check_wake(sdw))
419 		return 0;
420 
421 	/* disable WAKEEN interrupt ASAP to prevent interrupt flood */
422 	sdw_intel_shim_wake(sdw, false);
423 
424 	/*
425 	 * resume the Master, which will generate a bus reset and result in
426 	 * Slaves re-attaching and be re-enumerated. The SoundWire physical
427 	 * device which generated the wake will trigger an interrupt, which
428 	 * will in turn cause the corresponding Linux Slave device to be
429 	 * resumed and the Slave codec driver to check the status.
430 	 */
431 	pm_request_resume(dev);
432 
433 	return 0;
434 }
435 
436 /*
437  * PM calls
438  */
439 
440 static int intel_resume_child_device(struct device *dev, void *data)
441 {
442 	int ret;
443 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
444 
445 	if (!slave->probed) {
446 		dev_dbg(dev, "skipping device, no probed driver\n");
447 		return 0;
448 	}
449 	if (!slave->dev_num_sticky) {
450 		dev_dbg(dev, "skipping device, never detected on bus\n");
451 		return 0;
452 	}
453 
454 	ret = pm_request_resume(dev);
455 	if (ret < 0) {
456 		dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
457 		return ret;
458 	}
459 
460 	return 0;
461 }
462 
463 static int __maybe_unused intel_pm_prepare(struct device *dev)
464 {
465 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
466 	struct sdw_intel *sdw = cdns_to_intel(cdns);
467 	struct sdw_bus *bus = &cdns->bus;
468 	u32 clock_stop_quirks;
469 	int ret;
470 
471 	if (bus->prop.hw_disabled || !sdw->startup_done) {
472 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
473 			bus->link_id);
474 		return 0;
475 	}
476 
477 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
478 
479 	if (pm_runtime_suspended(dev) &&
480 	    pm_runtime_suspended(dev->parent) &&
481 	    ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
482 	     !clock_stop_quirks)) {
483 		/*
484 		 * if we've enabled clock stop, and the parent is suspended, the SHIM registers
485 		 * are not accessible and the shim wake cannot be disabled.
486 		 * The only solution is to resume the entire bus to full power
487 		 */
488 
489 		/*
490 		 * If any operation in this block fails, we keep going since we don't want
491 		 * to prevent system suspend from happening and errors should be recoverable
492 		 * on resume.
493 		 */
494 
495 		/*
496 		 * first resume the device for this link. This will also by construction
497 		 * resume the PCI parent device.
498 		 */
499 		ret = pm_request_resume(dev);
500 		if (ret < 0) {
501 			dev_err(dev, "%s: pm_request_resume failed: %d\n", __func__, ret);
502 			return 0;
503 		}
504 
505 		/*
506 		 * Continue resuming the entire bus (parent + child devices) to exit
507 		 * the clock stop mode. If there are no devices connected on this link
508 		 * this is a no-op.
509 		 * The resume to full power could have been implemented with a .prepare
510 		 * step in SoundWire codec drivers. This would however require a lot
511 		 * of code to handle an Intel-specific corner case. It is simpler in
512 		 * practice to add a loop at the link level.
513 		 */
514 		ret = device_for_each_child(bus->dev, NULL, intel_resume_child_device);
515 
516 		if (ret < 0)
517 			dev_err(dev, "%s: intel_resume_child_device failed: %d\n", __func__, ret);
518 	}
519 
520 	return 0;
521 }
522 
523 static int __maybe_unused intel_suspend(struct device *dev)
524 {
525 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
526 	struct sdw_intel *sdw = cdns_to_intel(cdns);
527 	struct sdw_bus *bus = &cdns->bus;
528 	u32 clock_stop_quirks;
529 	int ret;
530 
531 	if (bus->prop.hw_disabled || !sdw->startup_done) {
532 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
533 			bus->link_id);
534 		return 0;
535 	}
536 
537 	if (pm_runtime_suspended(dev)) {
538 		dev_dbg(dev, "pm_runtime status: suspended\n");
539 
540 		clock_stop_quirks = sdw->link_res->clock_stop_quirks;
541 
542 		if ((clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) ||
543 		    !clock_stop_quirks) {
544 
545 			if (pm_runtime_suspended(dev->parent)) {
546 				/*
547 				 * paranoia check: this should not happen with the .prepare
548 				 * resume to full power
549 				 */
550 				dev_err(dev, "%s: invalid config: parent is suspended\n", __func__);
551 			} else {
552 				sdw_intel_shim_wake(sdw, false);
553 			}
554 		}
555 
556 		return 0;
557 	}
558 
559 	ret = sdw_intel_stop_bus(sdw, false);
560 	if (ret < 0) {
561 		dev_err(dev, "%s: cannot stop bus: %d\n", __func__, ret);
562 		return ret;
563 	}
564 
565 	return 0;
566 }
567 
568 static int __maybe_unused intel_suspend_runtime(struct device *dev)
569 {
570 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
571 	struct sdw_intel *sdw = cdns_to_intel(cdns);
572 	struct sdw_bus *bus = &cdns->bus;
573 	u32 clock_stop_quirks;
574 	int ret;
575 
576 	if (bus->prop.hw_disabled || !sdw->startup_done) {
577 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
578 			bus->link_id);
579 		return 0;
580 	}
581 
582 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
583 
584 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
585 		ret = sdw_intel_stop_bus(sdw, false);
586 		if (ret < 0) {
587 			dev_err(dev, "%s: cannot stop bus during teardown: %d\n",
588 				__func__, ret);
589 			return ret;
590 		}
591 	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET || !clock_stop_quirks) {
592 		ret = sdw_intel_stop_bus(sdw, true);
593 		if (ret < 0) {
594 			dev_err(dev, "%s: cannot stop bus during clock_stop: %d\n",
595 				__func__, ret);
596 			return ret;
597 		}
598 	} else {
599 		dev_err(dev, "%s clock_stop_quirks %x unsupported\n",
600 			__func__, clock_stop_quirks);
601 		ret = -EINVAL;
602 	}
603 
604 	return ret;
605 }
606 
607 static int __maybe_unused intel_resume(struct device *dev)
608 {
609 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
610 	struct sdw_intel *sdw = cdns_to_intel(cdns);
611 	struct sdw_bus *bus = &cdns->bus;
612 	int link_flags;
613 	int ret;
614 
615 	if (bus->prop.hw_disabled || !sdw->startup_done) {
616 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
617 			bus->link_id);
618 		return 0;
619 	}
620 
621 	link_flags = md_flags >> (bus->link_id * 8);
622 
623 	if (pm_runtime_suspended(dev)) {
624 		dev_dbg(dev, "pm_runtime status was suspended, forcing active\n");
625 
626 		/* follow required sequence from runtime_pm.rst */
627 		pm_runtime_disable(dev);
628 		pm_runtime_set_active(dev);
629 		pm_runtime_mark_last_busy(dev);
630 		pm_runtime_enable(dev);
631 
632 		pm_runtime_resume(bus->dev);
633 
634 		link_flags = md_flags >> (bus->link_id * 8);
635 
636 		if (!(link_flags & SDW_INTEL_MASTER_DISABLE_PM_RUNTIME_IDLE))
637 			pm_runtime_idle(dev);
638 	}
639 
640 	ret = sdw_intel_link_power_up(sdw);
641 	if (ret) {
642 		dev_err(dev, "%s failed: %d\n", __func__, ret);
643 		return ret;
644 	}
645 
646 	/*
647 	 * make sure all Slaves are tagged as UNATTACHED and provide
648 	 * reason for reinitialization
649 	 */
650 	sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
651 
652 	ret = sdw_intel_start_bus(sdw);
653 	if (ret < 0) {
654 		dev_err(dev, "cannot start bus during resume\n");
655 		sdw_intel_link_power_down(sdw);
656 		return ret;
657 	}
658 
659 	/*
660 	 * after system resume, the pm_runtime suspend() may kick in
661 	 * during the enumeration, before any children device force the
662 	 * master device to remain active.  Using pm_runtime_get()
663 	 * routines is not really possible, since it'd prevent the
664 	 * master from suspending.
665 	 * A reasonable compromise is to update the pm_runtime
666 	 * counters and delay the pm_runtime suspend by several
667 	 * seconds, by when all enumeration should be complete.
668 	 */
669 	pm_runtime_mark_last_busy(bus->dev);
670 	pm_runtime_mark_last_busy(dev);
671 
672 	return 0;
673 }
674 
675 static int __maybe_unused intel_resume_runtime(struct device *dev)
676 {
677 	struct sdw_cdns *cdns = dev_get_drvdata(dev);
678 	struct sdw_intel *sdw = cdns_to_intel(cdns);
679 	struct sdw_bus *bus = &cdns->bus;
680 	u32 clock_stop_quirks;
681 	int ret;
682 
683 	if (bus->prop.hw_disabled || !sdw->startup_done) {
684 		dev_dbg(dev, "SoundWire master %d is disabled or not-started, ignoring\n",
685 			bus->link_id);
686 		return 0;
687 	}
688 
689 	/* unconditionally disable WAKEEN interrupt */
690 	sdw_intel_shim_wake(sdw, false);
691 
692 	clock_stop_quirks = sdw->link_res->clock_stop_quirks;
693 
694 	if (clock_stop_quirks & SDW_INTEL_CLK_STOP_TEARDOWN) {
695 		ret = sdw_intel_link_power_up(sdw);
696 		if (ret) {
697 			dev_err(dev, "%s: power_up failed after teardown: %d\n", __func__, ret);
698 			return ret;
699 		}
700 
701 		/*
702 		 * make sure all Slaves are tagged as UNATTACHED and provide
703 		 * reason for reinitialization
704 		 */
705 		sdw_clear_slave_status(bus, SDW_UNATTACH_REQUEST_MASTER_RESET);
706 
707 		ret = sdw_intel_start_bus(sdw);
708 		if (ret < 0) {
709 			dev_err(dev, "%s: cannot start bus after teardown: %d\n", __func__, ret);
710 			sdw_intel_link_power_down(sdw);
711 			return ret;
712 		}
713 
714 	} else if (clock_stop_quirks & SDW_INTEL_CLK_STOP_BUS_RESET) {
715 		ret = sdw_intel_link_power_up(sdw);
716 		if (ret) {
717 			dev_err(dev, "%s: power_up failed after bus reset: %d\n", __func__, ret);
718 			return ret;
719 		}
720 
721 		ret = sdw_intel_start_bus_after_reset(sdw);
722 		if (ret < 0) {
723 			dev_err(dev, "%s: cannot start bus after reset: %d\n", __func__, ret);
724 			sdw_intel_link_power_down(sdw);
725 			return ret;
726 		}
727 	} else if (!clock_stop_quirks) {
728 
729 		sdw_intel_check_clock_stop(sdw);
730 
731 		ret = sdw_intel_link_power_up(sdw);
732 		if (ret) {
733 			dev_err(dev, "%s: power_up failed: %d\n", __func__, ret);
734 			return ret;
735 		}
736 
737 		ret = sdw_intel_start_bus_after_clock_stop(sdw);
738 		if (ret < 0) {
739 			dev_err(dev, "%s: cannot start bus after clock stop: %d\n", __func__, ret);
740 			sdw_intel_link_power_down(sdw);
741 			return ret;
742 		}
743 	} else {
744 		dev_err(dev, "%s: clock_stop_quirks %x unsupported\n",
745 			__func__, clock_stop_quirks);
746 		ret = -EINVAL;
747 	}
748 
749 	return ret;
750 }
751 
752 static const struct dev_pm_ops intel_pm = {
753 	.prepare = intel_pm_prepare,
754 	SET_SYSTEM_SLEEP_PM_OPS(intel_suspend, intel_resume)
755 	SET_RUNTIME_PM_OPS(intel_suspend_runtime, intel_resume_runtime, NULL)
756 };
757 
758 static const struct auxiliary_device_id intel_link_id_table[] = {
759 	{ .name = "soundwire_intel.link" },
760 	{},
761 };
762 MODULE_DEVICE_TABLE(auxiliary, intel_link_id_table);
763 
764 static struct auxiliary_driver sdw_intel_drv = {
765 	.probe = intel_link_probe,
766 	.remove = intel_link_remove,
767 	.driver = {
768 		/* auxiliary_driver_register() sets .name to be the modname */
769 		.pm = &intel_pm,
770 	},
771 	.id_table = intel_link_id_table
772 };
773 module_auxiliary_driver(sdw_intel_drv);
774 
775 MODULE_LICENSE("Dual BSD/GPL");
776 MODULE_DESCRIPTION("Intel Soundwire Link Driver");
777