Linux Audio

Check our new training course

Loading...
Note: File does not exist in v3.1.
  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 * @drv: 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 * @drv: 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 * @codecs_pdata: codec platform data
342 *
343 * Register a digital controller which can control up to 4 ac97 codecs. This is
344 * the controller side of the AC97 AC-link, while the slave side are the codecs.
345 *
346 * Returns a valid controller upon success, negative pointer value upon error
347 */
348struct ac97_controller *snd_ac97_controller_register(
349	const struct ac97_controller_ops *ops, struct device *dev,
350	unsigned short slots_available, void **codecs_pdata)
351{
352	struct ac97_controller *ac97_ctrl;
353	int ret, i;
354
355	ac97_ctrl = kzalloc(sizeof(*ac97_ctrl), GFP_KERNEL);
356	if (!ac97_ctrl)
357		return ERR_PTR(-ENOMEM);
358
359	for (i = 0; i < AC97_BUS_MAX_CODECS && codecs_pdata; i++)
360		ac97_ctrl->codecs_pdata[i] = codecs_pdata[i];
361
362	ac97_ctrl->ops = ops;
363	ac97_ctrl->slots_available = slots_available;
364	ac97_ctrl->parent = dev;
365	ret = ac97_add_adapter(ac97_ctrl);
366
367	if (ret)
368		goto err;
369	ac97_bus_reset(ac97_ctrl);
370	ac97_bus_scan(ac97_ctrl);
371
372	return ac97_ctrl;
373err:
374	kfree(ac97_ctrl);
375	return ERR_PTR(ret);
376}
377EXPORT_SYMBOL_GPL(snd_ac97_controller_register);
378
379/**
380 * snd_ac97_controller_unregister - unregister an ac97 controller
381 * @ac97_ctrl: the device previously provided to ac97_controller_register()
382 *
383 */
384void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
385{
386	ac97_del_adapter(ac97_ctrl);
387}
388EXPORT_SYMBOL_GPL(snd_ac97_controller_unregister);
389
390#ifdef CONFIG_PM
391static int ac97_pm_runtime_suspend(struct device *dev)
392{
393	struct ac97_codec_device *codec = to_ac97_device(dev);
394	int ret = pm_generic_runtime_suspend(dev);
395
396	if (ret == 0 && dev->driver) {
397		if (pm_runtime_is_irq_safe(dev))
398			clk_disable(codec->clk);
399		else
400			clk_disable_unprepare(codec->clk);
401	}
402
403	return ret;
404}
405
406static int ac97_pm_runtime_resume(struct device *dev)
407{
408	struct ac97_codec_device *codec = to_ac97_device(dev);
409	int ret;
410
411	if (dev->driver) {
412		if (pm_runtime_is_irq_safe(dev))
413			ret = clk_enable(codec->clk);
414		else
415			ret = clk_prepare_enable(codec->clk);
416		if (ret)
417			return ret;
418	}
419
420	return pm_generic_runtime_resume(dev);
421}
422#endif /* CONFIG_PM */
423
424static const struct dev_pm_ops ac97_pm = {
425	.suspend	= pm_generic_suspend,
426	.resume		= pm_generic_resume,
427	.freeze		= pm_generic_freeze,
428	.thaw		= pm_generic_thaw,
429	.poweroff	= pm_generic_poweroff,
430	.restore	= pm_generic_restore,
431	SET_RUNTIME_PM_OPS(
432		ac97_pm_runtime_suspend,
433		ac97_pm_runtime_resume,
434		NULL)
435};
436
437static int ac97_get_enable_clk(struct ac97_codec_device *adev)
438{
439	int ret;
440
441	adev->clk = clk_get(&adev->dev, "ac97_clk");
442	if (IS_ERR(adev->clk))
443		return PTR_ERR(adev->clk);
444
445	ret = clk_prepare_enable(adev->clk);
446	if (ret)
447		clk_put(adev->clk);
448
449	return ret;
450}
451
452static void ac97_put_disable_clk(struct ac97_codec_device *adev)
453{
454	clk_disable_unprepare(adev->clk);
455	clk_put(adev->clk);
456}
457
458static ssize_t vendor_id_show(struct device *dev,
459			      struct device_attribute *attr, char *buf)
460{
461	struct ac97_codec_device *codec = to_ac97_device(dev);
462
463	return sysfs_emit(buf, "%08x", codec->vendor_id);
464}
465static DEVICE_ATTR_RO(vendor_id);
466
467static struct attribute *ac97_dev_attrs[] = {
468	&dev_attr_vendor_id.attr,
469	NULL,
470};
471ATTRIBUTE_GROUPS(ac97_dev);
472
473static int ac97_bus_match(struct device *dev, const struct device_driver *drv)
474{
475	struct ac97_codec_device *adev = to_ac97_device(dev);
476	const struct ac97_codec_driver *adrv = to_ac97_driver(drv);
477	const struct ac97_id *id = adrv->id_table;
478	int i = 0;
479
480	if (adev->vendor_id == 0x0 || adev->vendor_id == 0xffffffff)
481		return false;
482
483	do {
484		if (ac97_ids_match(id[i].id, adev->vendor_id, id[i].mask))
485			return true;
486	} while (id[i++].id);
487
488	return false;
489}
490
491static int ac97_bus_probe(struct device *dev)
492{
493	struct ac97_codec_device *adev = to_ac97_device(dev);
494	struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
495	int ret;
496
497	ret = ac97_get_enable_clk(adev);
498	if (ret)
499		return ret;
500
501	pm_runtime_get_noresume(dev);
502	pm_runtime_set_active(dev);
503	pm_runtime_enable(dev);
504
505	ret = adrv->probe(adev);
506	if (ret == 0)
507		return 0;
508
509	pm_runtime_disable(dev);
510	pm_runtime_set_suspended(dev);
511	pm_runtime_put_noidle(dev);
512	ac97_put_disable_clk(adev);
513
514	return ret;
515}
516
517static void ac97_bus_remove(struct device *dev)
518{
519	struct ac97_codec_device *adev = to_ac97_device(dev);
520	struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver);
521	int ret;
522
523	ret = pm_runtime_resume_and_get(dev);
524	if (ret < 0)
525		return;
526
527	adrv->remove(adev);
528	pm_runtime_put_noidle(dev);
529	ac97_put_disable_clk(adev);
530
531	pm_runtime_disable(dev);
532}
533
534const struct bus_type ac97_bus_type = {
535	.name		= "ac97bus",
536	.dev_groups	= ac97_dev_groups,
537	.match		= ac97_bus_match,
538	.pm		= &ac97_pm,
539	.probe		= ac97_bus_probe,
540	.remove		= ac97_bus_remove,
541};
542
543static int __init ac97_bus_init(void)
544{
545	return bus_register(&ac97_bus_type);
546}
547subsys_initcall(ac97_bus_init);
548
549static void __exit ac97_bus_exit(void)
550{
551	bus_unregister(&ac97_bus_type);
552}
553module_exit(ac97_bus_exit);
554
555MODULE_DESCRIPTION("AC97 bus interface");
556MODULE_LICENSE("GPL");
557MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");