1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr>
4 */
5
6#include <linux/module.h>
7#include <linux/bitops.h>
8#include <linux/clk.h>
9#include <linux/device.h>
10#include <linux/idr.h>
11#include <linux/list.h>
12#include <linux/mutex.h>
13#include <linux/of.h>
14#include <linux/pm.h>
15#include <linux/pm_runtime.h>
16#include <linux/slab.h>
17#include <linux/sysfs.h>
18#include <sound/ac97_codec.h>
19#include <sound/ac97/codec.h>
20#include <sound/ac97/controller.h>
21#include <sound/ac97/regs.h>
22
23#include "ac97_core.h"
24
25/*
26 * Protects ac97_controllers and each ac97_controller structure.
27 */
28static DEFINE_MUTEX(ac97_controllers_mutex);
29static DEFINE_IDR(ac97_adapter_idr);
30static LIST_HEAD(ac97_controllers);
31
32static inline struct ac97_controller*
33to_ac97_controller(struct device *ac97_adapter)
34{
35	return container_of(ac97_adapter, struct ac97_controller, adap);
36}
37
38static int ac97_unbound_ctrl_write(struct ac97_controller *adrv, int slot,
39		     unsigned short reg, unsigned short val)
40{
41	return -ENODEV;
42}
43
44static int ac97_unbound_ctrl_read(struct ac97_controller *adrv, int slot,
45				  unsigned short reg)
46{
47	return -ENODEV;
48}
49
50static const struct ac97_controller_ops ac97_unbound_ctrl_ops = {
51	.write = ac97_unbound_ctrl_write,
52	.read = ac97_unbound_ctrl_read,
53};
54
55static struct ac97_controller ac97_unbound_ctrl = {
56	.ops = &ac97_unbound_ctrl_ops,
57};
58
59static struct ac97_codec_device *
60ac97_codec_find(struct ac97_controller *ac97_ctrl, unsigned int codec_num)
61{
62	if (codec_num >= AC97_BUS_MAX_CODECS)
63		return ERR_PTR(-EINVAL);
64
65	return ac97_ctrl->codecs[codec_num];
66}
67
68static struct device_node *
69ac97_of_get_child_device(struct ac97_controller *ac97_ctrl, int idx,
70			 unsigned int vendor_id)
71{
72	struct device_node *node;
73	u32 reg;
74	char compat[] = "ac97,0000,0000";
75
76	snprintf(compat, sizeof(compat), "ac97,%04x,%04x",
77		 vendor_id >> 16, vendor_id & 0xffff);
78
79	for_each_child_of_node(ac97_ctrl->parent->of_node, node) {
80		if ((idx != of_property_read_u32(node, "reg", &reg)) ||
81		    !of_device_is_compatible(node, compat))
82			continue;
83		return node;
84	}
85
86	return NULL;
87}
88
89static void ac97_codec_release(struct device *dev)
90{
91	struct ac97_codec_device *adev;
92	struct ac97_controller *ac97_ctrl;
93
94	adev = to_ac97_device(dev);
95	ac97_ctrl = adev->ac97_ctrl;
96	ac97_ctrl->codecs[adev->num] = NULL;
97	of_node_put(dev->of_node);
98	kfree(adev);
99}
100
101static int ac97_codec_add(struct ac97_controller *ac97_ctrl, int idx,
102		   unsigned int vendor_id)
103{
104	struct ac97_codec_device *codec;
105	int ret;
106
107	codec = kzalloc(sizeof(*codec), GFP_KERNEL);
108	if (!codec)
109		return -ENOMEM;
110	ac97_ctrl->codecs[idx] = codec;
111	codec->vendor_id = vendor_id;
112	codec->dev.release = ac97_codec_release;
113	codec->dev.bus = &ac97_bus_type;
114	codec->dev.parent = &ac97_ctrl->adap;
115	codec->num = idx;
116	codec->ac97_ctrl = ac97_ctrl;
117
118	device_initialize(&codec->dev);
119	dev_set_name(&codec->dev, "%s:%u", dev_name(ac97_ctrl->parent), idx);
120	codec->dev.of_node = ac97_of_get_child_device(ac97_ctrl, idx,
121						      vendor_id);
122
123	ret = device_add(&codec->dev);
124	if (ret) {
125		put_device(&codec->dev);
126		return ret;
127	}
128
129	return 0;
130}
131
132unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv,
133				   unsigned int codec_num)
134{
135	unsigned short vid1, vid2;
136	int ret;
137
138	ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID1);
139	vid1 = (ret & 0xffff);
140	if (ret < 0)
141		return 0;
142
143	ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID2);
144	vid2 = (ret & 0xffff);
145	if (ret < 0)
146		return 0;
147
148	dev_dbg(&adrv->adap, "%s(codec_num=%u): vendor_id=0x%08x\n",
149		__func__, codec_num, AC97_ID(vid1, vid2));
150	return AC97_ID(vid1, vid2);
151}
152
153static int ac97_bus_scan(struct ac97_controller *ac97_ctrl)
154{
155	int ret, i;
156	unsigned int vendor_id;
157
158	for (i = 0; i < AC97_BUS_MAX_CODECS; i++) {
159		if (ac97_codec_find(ac97_ctrl, i))
160			continue;
161		if (!(ac97_ctrl->slots_available & BIT(i)))
162			continue;
163		vendor_id = snd_ac97_bus_scan_one(ac97_ctrl, i);
164		if (!vendor_id)
165			continue;
166
167		ret = ac97_codec_add(ac97_ctrl, i, vendor_id);
168		if (ret < 0)
169			return ret;
170	}
171	return 0;
172}
173
174static int ac97_bus_reset(struct ac97_controller *ac97_ctrl)
175{
176	ac97_ctrl->ops->reset(ac97_ctrl);
177
178	return 0;
179}
180
181/**
182 * snd_ac97_codec_driver_register - register an AC97 codec driver
183 * @dev: AC97 driver codec to register
184 *
185 * Register an AC97 codec driver to the ac97 bus driver, aka. the AC97 digital
186 * controller.
187 *
188 * Returns 0 on success or error code
189 */
190int snd_ac97_codec_driver_register(struct ac97_codec_driver *drv)
191{
192	drv->driver.bus = &ac97_bus_type;
193	return driver_register(&drv->driver);
194}
195EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_register);
196
197/**
198 * snd_ac97_codec_driver_unregister - unregister an AC97 codec driver
199 * @dev: AC97 codec driver to unregister
200 *
201 * Unregister a previously registered ac97 codec driver.
202 */
203void snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv)
204{
205	driver_unregister(&drv->driver);
206}
207EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_unregister);
208
209/**
210 * snd_ac97_codec_get_platdata - get platform_data
211 * @adev: the ac97 codec device
212 *
213 * For legacy platforms, in order to have platform_data in codec drivers
214 * available, while ac97 device are auto-created upon probe, this retrieves the
215 * platdata which was setup on ac97 controller registration.
216 *
217 * Returns the platform data pointer
218 */
219void *snd_ac97_codec_get_platdata(const struct ac97_codec_device *adev)
220{
221	struct ac97_controller *ac97_ctrl = adev->ac97_ctrl;
222
223	return ac97_ctrl->codecs_pdata[adev->num];
224}
225EXPORT_SYMBOL_GPL(snd_ac97_codec_get_platdata);
226
227static void ac97_ctrl_codecs_unregister(struct ac97_controller *ac97_ctrl)
228{
229	int i;
230
231	for (i = 0; i < AC97_BUS_MAX_CODECS; i++)
232		if (ac97_ctrl->codecs[i]) {
233			ac97_ctrl->codecs[i]->ac97_ctrl = &ac97_unbound_ctrl;
234			device_unregister(&ac97_ctrl->codecs[i]->dev);
235		}
236}
237
238static ssize_t cold_reset_store(struct device *dev,
239				struct device_attribute *attr, const char *buf,
240				size_t len)
241{
242	struct ac97_controller *ac97_ctrl;
243
244	mutex_lock(&ac97_controllers_mutex);
245	ac97_ctrl = to_ac97_controller(dev);
246	ac97_ctrl->ops->reset(ac97_ctrl);
247	mutex_unlock(&ac97_controllers_mutex);
248	return len;
249}
250static DEVICE_ATTR_WO(cold_reset);
251
252static ssize_t warm_reset_store(struct device *dev,
253				struct device_attribute *attr, const char *buf,
254				size_t len)
255{
256	struct ac97_controller *ac97_ctrl;
257
258	if (!dev)
259		return -ENODEV;
260
261	mutex_lock(&ac97_controllers_mutex);
262	ac97_ctrl = to_ac97_controller(dev);
263	ac97_ctrl->ops->warm_reset(ac97_ctrl);
264	mutex_unlock(&ac97_controllers_mutex);
265	return len;
266}
267static DEVICE_ATTR_WO(warm_reset);
268
269static struct attribute *ac97_controller_device_attrs[] = {
270	&dev_attr_cold_reset.attr,
271	&dev_attr_warm_reset.attr,
272	NULL
273};
274
275static const struct attribute_group ac97_adapter_attr_group = {
276	.name	= "ac97_operations",
277	.attrs	= ac97_controller_device_attrs,
278};
279
280static const struct attribute_group *ac97_adapter_groups[] = {
281	&ac97_adapter_attr_group,
282	NULL,
283};
284
285static void ac97_del_adapter(struct ac97_controller *ac97_ctrl)
286{
287	mutex_lock(&ac97_controllers_mutex);
288	ac97_ctrl_codecs_unregister(ac97_ctrl);
289	list_del(&ac97_ctrl->controllers);
290	mutex_unlock(&ac97_controllers_mutex);
291
292	device_unregister(&ac97_ctrl->adap);
293}
294
295static void ac97_adapter_release(struct device *dev)
296{
297	struct ac97_controller *ac97_ctrl;
298
299	ac97_ctrl = to_ac97_controller(dev);
300	idr_remove(&ac97_adapter_idr, ac97_ctrl->nr);
301	dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n",
302		dev_name(ac97_ctrl->parent));
303}
304
305static const struct device_type ac97_adapter_type = {
306	.groups		= ac97_adapter_groups,
307	.release	= ac97_adapter_release,
308};
309
310static int ac97_add_adapter(struct ac97_controller *ac97_ctrl)
311{
312	int ret;
313
314	mutex_lock(&ac97_controllers_mutex);
315	ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL);
316	ac97_ctrl->nr = ret;
317	if (ret >= 0) {
318		dev_set_name(&ac97_ctrl->adap, "ac97-%d", ret);
319		ac97_ctrl->adap.type = &ac97_adapter_type;
320		ac97_ctrl->adap.parent = ac97_ctrl->parent;
321		ret = device_register(&ac97_ctrl->adap);
322		if (ret)
323			put_device(&ac97_ctrl->adap);
324	}
325	if (!ret)
326		list_add(&ac97_ctrl->controllers, &ac97_controllers);
327	mutex_unlock(&ac97_controllers_mutex);
328
329	if (!ret)
330		dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n",
331			dev_name(ac97_ctrl->parent));
332	return ret;
333}
334
335/**
336 * snd_ac97_controller_register - register an ac97 controller
337 * @ops: the ac97 bus operations
338 * @dev: the device providing the ac97 DC function
339 * @slots_available: mask of the ac97 codecs that can be scanned and probed
340 *                   bit0 => codec 0, bit1 => codec 1 ... bit 3 => codec 3
341 *
342 * Register a digital controller which can control up to 4 ac97 codecs. This is
343 * the controller side of the AC97 AC-link, while the slave side are the codecs.
344 *
345 * Returns a valid controller upon success, negative pointer value upon error
346 */
347struct ac97_controller *snd_ac97_controller_register(
348	const struct ac97_controller_ops *ops, struct device *dev,
349	unsigned short slots_available, void **codecs_pdata)
350{
351	struct ac97_controller *ac97_ctrl;
352	int ret, i;
353
354	ac97_ctrl = kzalloc(sizeof(*ac97_ctrl), GFP_KERNEL);
355	if (!ac97_ctrl)
356		return ERR_PTR(-ENOMEM);
357
358	for (i = 0; i < AC97_BUS_MAX_CODECS && codecs_pdata; i++)
359		ac97_ctrl->codecs_pdata[i] = codecs_pdata[i];
360
361	ac97_ctrl->ops = ops;
362	ac97_ctrl->slots_available = slots_available;
363	ac97_ctrl->parent = dev;
364	ret = ac97_add_adapter(ac97_ctrl);
365
366	if (ret)
367		goto err;
368	ac97_bus_reset(ac97_ctrl);
369	ac97_bus_scan(ac97_ctrl);
370
371	return ac97_ctrl;
372err:
373	kfree(ac97_ctrl);
374	return ERR_PTR(ret);
375}
376EXPORT_SYMBOL_GPL(snd_ac97_controller_register);
377
378/**
379 * snd_ac97_controller_unregister - unregister an ac97 controller
380 * @ac97_ctrl: the device previously provided to ac97_controller_register()
381 *
382 */
383void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
384{
385	ac97_del_adapter(ac97_ctrl);
386}
387EXPORT_SYMBOL_GPL(snd_ac97_controller_unregister);
388
389#ifdef CONFIG_PM
390static int ac97_pm_runtime_suspend(struct device *dev)
391{
392	struct ac97_codec_device *codec = to_ac97_device(dev);
393	int ret = pm_generic_runtime_suspend(dev);
394
395	if (ret == 0 && dev->driver) {
396		if (pm_runtime_is_irq_safe(dev))
397			clk_disable(codec->clk);
398		else
399			clk_disable_unprepare(codec->clk);
400	}
401
402	return ret;
403}
404
405static int ac97_pm_runtime_resume(struct device *dev)
406{
407	struct ac97_codec_device *codec = to_ac97_device(dev);
408	int ret;
409
410	if (dev->driver) {
411		if (pm_runtime_is_irq_safe(dev))
412			ret = clk_enable(codec->clk);
413		else
414			ret = clk_prepare_enable(codec->clk);
415		if (ret)
416			return ret;
417	}
418
419	return pm_generic_runtime_resume(dev);
420}
421#endif /* CONFIG_PM */
422
423static const struct dev_pm_ops ac97_pm = {
424	.suspend	= pm_generic_suspend,
425	.resume		= pm_generic_resume,
426	.freeze		= pm_generic_freeze,
427	.thaw		= pm_generic_thaw,
428	.poweroff	= pm_generic_poweroff,
429	.restore	= pm_generic_restore,
430	SET_RUNTIME_PM_OPS(
431		ac97_pm_runtime_suspend,
432		ac97_pm_runtime_resume,
433		NULL)
434};
435
436static int ac97_get_enable_clk(struct ac97_codec_device *adev)
437{
438	int ret;
439
440	adev->clk = clk_get(&adev->dev, "ac97_clk");
441	if (IS_ERR(adev->clk))
442		return PTR_ERR(adev->clk);
443
444	ret = clk_prepare_enable(adev->clk);
445	if (ret)
446		clk_put(adev->clk);
447
448	return ret;
449}
450
451static void ac97_put_disable_clk(struct ac97_codec_device *adev)
452{
453	clk_disable_unprepare(adev->clk);
454	clk_put(adev->clk);
455}
456
457static ssize_t vendor_id_show(struct device *dev,
458			      struct device_attribute *attr, char *buf)
459{
460	struct ac97_codec_device *codec = to_ac97_device(dev);
461
462	return sysfs_emit(buf, "%08x", codec->vendor_id);
463}
464static DEVICE_ATTR_RO(vendor_id);
465
466static struct attribute *ac97_dev_attrs[] = {
467	&dev_attr_vendor_id.attr,
468	NULL,
469};
470ATTRIBUTE_GROUPS(ac97_dev);
471
472static int ac97_bus_match(struct device *dev, struct device_driver *drv)
473{
474	struct ac97_codec_device *adev = to_ac97_device(dev);
475	struct ac97_codec_driver *adrv = to_ac97_driver(drv);
476	const struct ac97_id *id = adrv->id_table;
477	int i = 0;
478
479	if (adev->vendor_id == 0x0 || adev->vendor_id == 0xffffffff)
480		return false;
481
482	do {
483		if (ac97_ids_match(id[i].id, adev->vendor_id, id[i].mask))
484			return true;
485	} while (id[i++].id);
486
487	return false;
488}
489
490static int ac97_bus_probe(struct device *dev)
491{
492	struct ac97_codec_device *adev = to_ac97_device(dev);
493	struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
494	int ret;
495
496	ret = ac97_get_enable_clk(adev);
497	if (ret)
498		return ret;
499
500	pm_runtime_get_noresume(dev);
501	pm_runtime_set_active(dev);
502	pm_runtime_enable(dev);
503
504	ret = adrv->probe(adev);
505	if (ret == 0)
506		return 0;
507
508	pm_runtime_disable(dev);
509	pm_runtime_set_suspended(dev);
510	pm_runtime_put_noidle(dev);
511	ac97_put_disable_clk(adev);
512
513	return ret;
514}
515
516static void ac97_bus_remove(struct device *dev)
517{
518	struct ac97_codec_device *adev = to_ac97_device(dev);
519	struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
520	int ret;
521
522	ret = pm_runtime_resume_and_get(dev);
523	if (ret < 0)
524		return;
525
526	adrv->remove(adev);
527	pm_runtime_put_noidle(dev);
528	ac97_put_disable_clk(adev);
529
530	pm_runtime_disable(dev);
531}
532
533const struct bus_type ac97_bus_type = {
534	.name		= "ac97bus",
535	.dev_groups	= ac97_dev_groups,
536	.match		= ac97_bus_match,
537	.pm		= &ac97_pm,
538	.probe		= ac97_bus_probe,
539	.remove		= ac97_bus_remove,
540};
541
542static int __init ac97_bus_init(void)
543{
544	return bus_register(&ac97_bus_type);
545}
546subsys_initcall(ac97_bus_init);
547
548static void __exit ac97_bus_exit(void)
549{
550	bus_unregister(&ac97_bus_type);
551}
552module_exit(ac97_bus_exit);
553
554MODULE_LICENSE("GPL");
555MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
556