1/*
2 * i2sbus driver
3 *
4 * Copyright 2006-2008 Johannes Berg <johannes@sipsolutions.net>
5 *
6 * GPL v2, can be found in COPYING.
7 */
8
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/pci.h>
12#include <linux/interrupt.h>
13#include <linux/dma-mapping.h>
14#include <linux/of_address.h>
15#include <linux/of_irq.h>
16
17#include <sound/core.h>
18
19#include <asm/macio.h>
20#include <asm/dbdma.h>
21
22#include "../soundbus.h"
23#include "i2sbus.h"
24
25MODULE_LICENSE("GPL");
26MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
27MODULE_DESCRIPTION("Apple Soundbus: I2S support");
28
29static int force;
30module_param(force, int, 0444);
31MODULE_PARM_DESC(force, "Force loading i2sbus even when"
32			" no layout-id property is present");
33
34static const struct of_device_id i2sbus_match[] = {
35	{ .name = "i2s" },
36	{ }
37};
38
39MODULE_DEVICE_TABLE(of, i2sbus_match);
40
41static int alloc_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
42				       struct dbdma_command_mem *r,
43				       int numcmds)
44{
45	/* one more for rounding, one for branch back, one for stop command */
46	r->size = (numcmds + 3) * sizeof(struct dbdma_cmd);
47	/* We use the PCI APIs for now until the generic one gets fixed
48	 * enough or until we get some macio-specific versions
49	 */
50	r->space = dma_zalloc_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
51				       r->size, &r->bus_addr, GFP_KERNEL);
52	if (!r->space)
53		return -ENOMEM;
54
55	r->cmds = (void*)DBDMA_ALIGN(r->space);
56	r->bus_cmd_start = r->bus_addr +
57			   (dma_addr_t)((char*)r->cmds - (char*)r->space);
58
59	return 0;
60}
61
62static void free_dbdma_descriptor_ring(struct i2sbus_dev *i2sdev,
63				       struct dbdma_command_mem *r)
64{
65	if (!r->space) return;
66
67	dma_free_coherent(&macio_get_pci_dev(i2sdev->macio)->dev,
68			    r->size, r->space, r->bus_addr);
69}
70
71static void i2sbus_release_dev(struct device *dev)
72{
73	struct i2sbus_dev *i2sdev;
74	int i;
75
76	i2sdev = container_of(dev, struct i2sbus_dev, sound.ofdev.dev);
77	iounmap(i2sdev->intfregs);
78	iounmap(i2sdev->out.dbdma);
79	iounmap(i2sdev->in.dbdma);
80	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
81		release_and_free_resource(i2sdev->allocated_resource[i]);
82	free_dbdma_descriptor_ring(i2sdev, &i2sdev->out.dbdma_ring);
83	free_dbdma_descriptor_ring(i2sdev, &i2sdev->in.dbdma_ring);
84	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++)
85		free_irq(i2sdev->interrupts[i], i2sdev);
86	i2sbus_control_remove_dev(i2sdev->control, i2sdev);
87	mutex_destroy(&i2sdev->lock);
88	kfree(i2sdev);
89}
90
91static irqreturn_t i2sbus_bus_intr(int irq, void *devid)
92{
93	struct i2sbus_dev *dev = devid;
94	u32 intreg;
95
96	spin_lock(&dev->low_lock);
97	intreg = in_le32(&dev->intfregs->intr_ctl);
98
99	/* acknowledge interrupt reasons */
100	out_le32(&dev->intfregs->intr_ctl, intreg);
101
102	spin_unlock(&dev->low_lock);
103
104	return IRQ_HANDLED;
105}
106
107
108/*
109 * XXX FIXME: We test the layout_id's here to get the proper way of
110 * mapping in various registers, thanks to bugs in Apple device-trees.
111 * We could instead key off the machine model and the name of the i2s
112 * node (i2s-a). This we'll do when we move it all to macio_asic.c
113 * and have that export items for each sub-node too.
114 */
115static int i2sbus_get_and_fixup_rsrc(struct device_node *np, int index,
116				     int layout, struct resource *res)
117{
118	struct device_node *parent;
119	int pindex, rc = -ENXIO;
120	const u32 *reg;
121
122	/* Machines with layout 76 and 36 (K2 based) have a weird device
123	 * tree what we need to special case.
124	 * Normal machines just fetch the resource from the i2s-X node.
125	 * Darwin further divides normal machines into old and new layouts
126	 * with a subtely different code path but that doesn't seem necessary
127	 * in practice, they just bloated it. In addition, even on our K2
128	 * case the i2s-modem node, if we ever want to handle it, uses the
129	 * normal layout
130	 */
131	if (layout != 76 && layout != 36)
132		return of_address_to_resource(np, index, res);
133
134	parent = of_get_parent(np);
135	pindex = (index == aoa_resource_i2smmio) ? 0 : 1;
136	rc = of_address_to_resource(parent, pindex, res);
137	if (rc)
138		goto bail;
139	reg = of_get_property(np, "reg", NULL);
140	if (reg == NULL) {
141		rc = -ENXIO;
142		goto bail;
143	}
144	res->start += reg[index * 2];
145	res->end = res->start + reg[index * 2 + 1] - 1;
146 bail:
147	of_node_put(parent);
148	return rc;
149}
150
151/* FIXME: look at device node refcounting */
152static int i2sbus_add_dev(struct macio_dev *macio,
153			  struct i2sbus_control *control,
154			  struct device_node *np)
155{
156	struct i2sbus_dev *dev;
157	struct device_node *child = NULL, *sound = NULL;
158	struct resource *r;
159	int i, layout = 0, rlen, ok = force;
160	static const char *rnames[] = { "i2sbus: %s (control)",
161					"i2sbus: %s (tx)",
162					"i2sbus: %s (rx)" };
163	static irq_handler_t ints[] = {
164		i2sbus_bus_intr,
165		i2sbus_tx_intr,
166		i2sbus_rx_intr
167	};
168
169	if (strlen(np->name) != 5)
170		return 0;
171	if (strncmp(np->name, "i2s-", 4))
172		return 0;
173
174	dev = kzalloc(sizeof(struct i2sbus_dev), GFP_KERNEL);
175	if (!dev)
176		return 0;
177
178	i = 0;
179	while ((child = of_get_next_child(np, child))) {
180		if (strcmp(child->name, "sound") == 0) {
181			i++;
182			sound = child;
183		}
184	}
185	if (i == 1) {
186		const u32 *id = of_get_property(sound, "layout-id", NULL);
187
188		if (id) {
189			layout = *id;
190			snprintf(dev->sound.modalias, 32,
191				 "sound-layout-%d", layout);
192			ok = 1;
193		} else {
194			id = of_get_property(sound, "device-id", NULL);
195			/*
196			 * We probably cannot handle all device-id machines,
197			 * so restrict to those we do handle for now.
198			 */
199			if (id && (*id == 22 || *id == 14 || *id == 35 ||
200				   *id == 44)) {
201				snprintf(dev->sound.modalias, 32,
202					 "aoa-device-id-%d", *id);
203				ok = 1;
204				layout = -1;
205			}
206		}
207	}
208	/* for the time being, until we can handle non-layout-id
209	 * things in some fabric, refuse to attach if there is no
210	 * layout-id property or we haven't been forced to attach.
211	 * When there are two i2s busses and only one has a layout-id,
212	 * then this depends on the order, but that isn't important
213	 * either as the second one in that case is just a modem. */
214	if (!ok) {
215		kfree(dev);
216		return -ENODEV;
217	}
218
219	mutex_init(&dev->lock);
220	spin_lock_init(&dev->low_lock);
221	dev->sound.ofdev.archdata.dma_mask = macio->ofdev.archdata.dma_mask;
222	dev->sound.ofdev.dev.of_node = np;
223	dev->sound.ofdev.dev.dma_mask = &dev->sound.ofdev.archdata.dma_mask;
224	dev->sound.ofdev.dev.parent = &macio->ofdev.dev;
225	dev->sound.ofdev.dev.release = i2sbus_release_dev;
226	dev->sound.attach_codec = i2sbus_attach_codec;
227	dev->sound.detach_codec = i2sbus_detach_codec;
228	dev->sound.pcmid = -1;
229	dev->macio = macio;
230	dev->control = control;
231	dev->bus_number = np->name[4] - 'a';
232	INIT_LIST_HEAD(&dev->sound.codec_list);
233
234	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
235		dev->interrupts[i] = -1;
236		snprintf(dev->rnames[i], sizeof(dev->rnames[i]),
237			 rnames[i], np->name);
238	}
239	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
240		int irq = irq_of_parse_and_map(np, i);
241		if (request_irq(irq, ints[i], 0, dev->rnames[i], dev))
242			goto err;
243		dev->interrupts[i] = irq;
244	}
245
246
247	/* Resource handling is problematic as some device-trees contain
248	 * useless crap (ugh ugh ugh). We work around that here by calling
249	 * specific functions for calculating the appropriate resources.
250	 *
251	 * This will all be moved to macio_asic.c at one point
252	 */
253	for (i = aoa_resource_i2smmio; i <= aoa_resource_rxdbdma; i++) {
254		if (i2sbus_get_and_fixup_rsrc(np,i,layout,&dev->resources[i]))
255			goto err;
256		/* If only we could use our resource dev->resources[i]...
257		 * but request_resource doesn't know about parents and
258		 * contained resources...
259		 */
260		dev->allocated_resource[i] =
261			request_mem_region(dev->resources[i].start,
262					   resource_size(&dev->resources[i]),
263					   dev->rnames[i]);
264		if (!dev->allocated_resource[i]) {
265			printk(KERN_ERR "i2sbus: failed to claim resource %d!\n", i);
266			goto err;
267		}
268	}
269
270	r = &dev->resources[aoa_resource_i2smmio];
271	rlen = resource_size(r);
272	if (rlen < sizeof(struct i2s_interface_regs))
273		goto err;
274	dev->intfregs = ioremap(r->start, rlen);
275
276	r = &dev->resources[aoa_resource_txdbdma];
277	rlen = resource_size(r);
278	if (rlen < sizeof(struct dbdma_regs))
279		goto err;
280	dev->out.dbdma = ioremap(r->start, rlen);
281
282	r = &dev->resources[aoa_resource_rxdbdma];
283	rlen = resource_size(r);
284	if (rlen < sizeof(struct dbdma_regs))
285		goto err;
286	dev->in.dbdma = ioremap(r->start, rlen);
287
288	if (!dev->intfregs || !dev->out.dbdma || !dev->in.dbdma)
289		goto err;
290
291	if (alloc_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring,
292					MAX_DBDMA_COMMANDS))
293		goto err;
294	if (alloc_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring,
295					MAX_DBDMA_COMMANDS))
296		goto err;
297
298	if (i2sbus_control_add_dev(dev->control, dev)) {
299		printk(KERN_ERR "i2sbus: control layer didn't like bus\n");
300		goto err;
301	}
302
303	if (soundbus_add_one(&dev->sound)) {
304		printk(KERN_DEBUG "i2sbus: device registration error!\n");
305		goto err;
306	}
307
308	/* enable this cell */
309	i2sbus_control_cell(dev->control, dev, 1);
310	i2sbus_control_enable(dev->control, dev);
311	i2sbus_control_clock(dev->control, dev, 1);
312
313	return 1;
314 err:
315	for (i=0;i<3;i++)
316		if (dev->interrupts[i] != -1)
317			free_irq(dev->interrupts[i], dev);
318	free_dbdma_descriptor_ring(dev, &dev->out.dbdma_ring);
319	free_dbdma_descriptor_ring(dev, &dev->in.dbdma_ring);
320	iounmap(dev->intfregs);
321	iounmap(dev->out.dbdma);
322	iounmap(dev->in.dbdma);
323	for (i=0;i<3;i++)
324		release_and_free_resource(dev->allocated_resource[i]);
325	mutex_destroy(&dev->lock);
326	kfree(dev);
327	return 0;
328}
329
330static int i2sbus_probe(struct macio_dev* dev, const struct of_device_id *match)
331{
332	struct device_node *np = NULL;
333	int got = 0, err;
334	struct i2sbus_control *control = NULL;
335
336	err = i2sbus_control_init(dev, &control);
337	if (err)
338		return err;
339	if (!control) {
340		printk(KERN_ERR "i2sbus_control_init API breakage\n");
341		return -ENODEV;
342	}
343
344	while ((np = of_get_next_child(dev->ofdev.dev.of_node, np))) {
345		if (of_device_is_compatible(np, "i2sbus") ||
346		    of_device_is_compatible(np, "i2s-modem")) {
347			got += i2sbus_add_dev(dev, control, np);
348		}
349	}
350
351	if (!got) {
352		/* found none, clean up */
353		i2sbus_control_destroy(control);
354		return -ENODEV;
355	}
356
357	dev_set_drvdata(&dev->ofdev.dev, control);
358
359	return 0;
360}
361
362static int i2sbus_remove(struct macio_dev* dev)
363{
364	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
365	struct i2sbus_dev *i2sdev, *tmp;
366
367	list_for_each_entry_safe(i2sdev, tmp, &control->list, item)
368		soundbus_remove_one(&i2sdev->sound);
369
370	return 0;
371}
372
373#ifdef CONFIG_PM
374static int i2sbus_suspend(struct macio_dev* dev, pm_message_t state)
375{
376	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
377	struct codec_info_item *cii;
378	struct i2sbus_dev* i2sdev;
379	int err, ret = 0;
380
381	list_for_each_entry(i2sdev, &control->list, item) {
382		/* Notify Alsa */
383		/* Suspend PCM streams */
384		snd_pcm_suspend_all(i2sdev->sound.pcm);
385
386		/* Notify codecs */
387		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
388			err = 0;
389			if (cii->codec->suspend)
390				err = cii->codec->suspend(cii, state);
391			if (err)
392				ret = err;
393		}
394
395		/* wait until streams are stopped */
396		i2sbus_wait_for_stop_both(i2sdev);
397	}
398
399	return ret;
400}
401
402static int i2sbus_resume(struct macio_dev* dev)
403{
404	struct i2sbus_control *control = dev_get_drvdata(&dev->ofdev.dev);
405	struct codec_info_item *cii;
406	struct i2sbus_dev* i2sdev;
407	int err, ret = 0;
408
409	list_for_each_entry(i2sdev, &control->list, item) {
410		/* reset i2s bus format etc. */
411		i2sbus_pcm_prepare_both(i2sdev);
412
413		/* Notify codecs so they can re-initialize */
414		list_for_each_entry(cii, &i2sdev->sound.codec_list, list) {
415			err = 0;
416			if (cii->codec->resume)
417				err = cii->codec->resume(cii);
418			if (err)
419				ret = err;
420		}
421	}
422
423	return ret;
424}
425#endif /* CONFIG_PM */
426
427static int i2sbus_shutdown(struct macio_dev* dev)
428{
429	return 0;
430}
431
432static struct macio_driver i2sbus_drv = {
433	.driver = {
434		.name = "soundbus-i2s",
435		.owner = THIS_MODULE,
436		.of_match_table = i2sbus_match,
437	},
438	.probe = i2sbus_probe,
439	.remove = i2sbus_remove,
440#ifdef CONFIG_PM
441	.suspend = i2sbus_suspend,
442	.resume = i2sbus_resume,
443#endif
444	.shutdown = i2sbus_shutdown,
445};
446
447static int __init soundbus_i2sbus_init(void)
448{
449	return macio_register_driver(&i2sbus_drv);
450}
451
452static void __exit soundbus_i2sbus_exit(void)
453{
454	macio_unregister_driver(&i2sbus_drv);
455}
456
457module_init(soundbus_i2sbus_init);
458module_exit(soundbus_i2sbus_exit);
459