xref: /openbmc/linux/sound/hda/hdac_controller.c (revision e3b9f1e8)
1 /*
2  * HD-audio controller helpers
3  */
4 
5 #include <linux/kernel.h>
6 #include <linux/delay.h>
7 #include <linux/export.h>
8 #include <sound/core.h>
9 #include <sound/hdaudio.h>
10 #include <sound/hda_register.h>
11 
12 /* clear CORB read pointer properly */
13 static void azx_clear_corbrp(struct hdac_bus *bus)
14 {
15 	int timeout;
16 
17 	for (timeout = 1000; timeout > 0; timeout--) {
18 		if (snd_hdac_chip_readw(bus, CORBRP) & AZX_CORBRP_RST)
19 			break;
20 		udelay(1);
21 	}
22 	if (timeout <= 0)
23 		dev_err(bus->dev, "CORB reset timeout#1, CORBRP = %d\n",
24 			snd_hdac_chip_readw(bus, CORBRP));
25 
26 	snd_hdac_chip_writew(bus, CORBRP, 0);
27 	for (timeout = 1000; timeout > 0; timeout--) {
28 		if (snd_hdac_chip_readw(bus, CORBRP) == 0)
29 			break;
30 		udelay(1);
31 	}
32 	if (timeout <= 0)
33 		dev_err(bus->dev, "CORB reset timeout#2, CORBRP = %d\n",
34 			snd_hdac_chip_readw(bus, CORBRP));
35 }
36 
37 /**
38  * snd_hdac_bus_init_cmd_io - set up CORB/RIRB buffers
39  * @bus: HD-audio core bus
40  */
41 void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
42 {
43 	spin_lock_irq(&bus->reg_lock);
44 	/* CORB set up */
45 	bus->corb.addr = bus->rb.addr;
46 	bus->corb.buf = (__le32 *)bus->rb.area;
47 	snd_hdac_chip_writel(bus, CORBLBASE, (u32)bus->corb.addr);
48 	snd_hdac_chip_writel(bus, CORBUBASE, upper_32_bits(bus->corb.addr));
49 
50 	/* set the corb size to 256 entries (ULI requires explicitly) */
51 	snd_hdac_chip_writeb(bus, CORBSIZE, 0x02);
52 	/* set the corb write pointer to 0 */
53 	snd_hdac_chip_writew(bus, CORBWP, 0);
54 
55 	/* reset the corb hw read pointer */
56 	snd_hdac_chip_writew(bus, CORBRP, AZX_CORBRP_RST);
57 	if (!bus->corbrp_self_clear)
58 		azx_clear_corbrp(bus);
59 
60 	/* enable corb dma */
61 	snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
62 
63 	/* RIRB set up */
64 	bus->rirb.addr = bus->rb.addr + 2048;
65 	bus->rirb.buf = (__le32 *)(bus->rb.area + 2048);
66 	bus->rirb.wp = bus->rirb.rp = 0;
67 	memset(bus->rirb.cmds, 0, sizeof(bus->rirb.cmds));
68 	snd_hdac_chip_writel(bus, RIRBLBASE, (u32)bus->rirb.addr);
69 	snd_hdac_chip_writel(bus, RIRBUBASE, upper_32_bits(bus->rirb.addr));
70 
71 	/* set the rirb size to 256 entries (ULI requires explicitly) */
72 	snd_hdac_chip_writeb(bus, RIRBSIZE, 0x02);
73 	/* reset the rirb hw write pointer */
74 	snd_hdac_chip_writew(bus, RIRBWP, AZX_RIRBWP_RST);
75 	/* set N=1, get RIRB response interrupt for new entry */
76 	snd_hdac_chip_writew(bus, RINTCNT, 1);
77 	/* enable rirb dma and response irq */
78 	snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);
79 	spin_unlock_irq(&bus->reg_lock);
80 }
81 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
82 
83 /* wait for cmd dmas till they are stopped */
84 static void hdac_wait_for_cmd_dmas(struct hdac_bus *bus)
85 {
86 	unsigned long timeout;
87 
88 	timeout = jiffies + msecs_to_jiffies(100);
89 	while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
90 		&& time_before(jiffies, timeout))
91 		udelay(10);
92 
93 	timeout = jiffies + msecs_to_jiffies(100);
94 	while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
95 		&& time_before(jiffies, timeout))
96 		udelay(10);
97 }
98 
99 /**
100  * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
101  * @bus: HD-audio core bus
102  */
103 void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
104 {
105 	spin_lock_irq(&bus->reg_lock);
106 	/* disable ringbuffer DMAs */
107 	snd_hdac_chip_writeb(bus, RIRBCTL, 0);
108 	snd_hdac_chip_writeb(bus, CORBCTL, 0);
109 	spin_unlock_irq(&bus->reg_lock);
110 
111 	hdac_wait_for_cmd_dmas(bus);
112 
113 	spin_lock_irq(&bus->reg_lock);
114 	/* disable unsolicited responses */
115 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
116 	spin_unlock_irq(&bus->reg_lock);
117 }
118 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_cmd_io);
119 
120 static unsigned int azx_command_addr(u32 cmd)
121 {
122 	unsigned int addr = cmd >> 28;
123 
124 	if (snd_BUG_ON(addr >= HDA_MAX_CODECS))
125 		addr = 0;
126 	return addr;
127 }
128 
129 /**
130  * snd_hdac_bus_send_cmd - send a command verb via CORB
131  * @bus: HD-audio core bus
132  * @val: encoded verb value to send
133  *
134  * Returns zero for success or a negative error code.
135  */
136 int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
137 {
138 	unsigned int addr = azx_command_addr(val);
139 	unsigned int wp, rp;
140 
141 	spin_lock_irq(&bus->reg_lock);
142 
143 	bus->last_cmd[azx_command_addr(val)] = val;
144 
145 	/* add command to corb */
146 	wp = snd_hdac_chip_readw(bus, CORBWP);
147 	if (wp == 0xffff) {
148 		/* something wrong, controller likely turned to D3 */
149 		spin_unlock_irq(&bus->reg_lock);
150 		return -EIO;
151 	}
152 	wp++;
153 	wp %= AZX_MAX_CORB_ENTRIES;
154 
155 	rp = snd_hdac_chip_readw(bus, CORBRP);
156 	if (wp == rp) {
157 		/* oops, it's full */
158 		spin_unlock_irq(&bus->reg_lock);
159 		return -EAGAIN;
160 	}
161 
162 	bus->rirb.cmds[addr]++;
163 	bus->corb.buf[wp] = cpu_to_le32(val);
164 	snd_hdac_chip_writew(bus, CORBWP, wp);
165 
166 	spin_unlock_irq(&bus->reg_lock);
167 
168 	return 0;
169 }
170 EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
171 
172 #define AZX_RIRB_EX_UNSOL_EV	(1<<4)
173 
174 /**
175  * snd_hdac_bus_update_rirb - retrieve RIRB entries
176  * @bus: HD-audio core bus
177  *
178  * Usually called from interrupt handler.
179  */
180 void snd_hdac_bus_update_rirb(struct hdac_bus *bus)
181 {
182 	unsigned int rp, wp;
183 	unsigned int addr;
184 	u32 res, res_ex;
185 
186 	wp = snd_hdac_chip_readw(bus, RIRBWP);
187 	if (wp == 0xffff) {
188 		/* something wrong, controller likely turned to D3 */
189 		return;
190 	}
191 
192 	if (wp == bus->rirb.wp)
193 		return;
194 	bus->rirb.wp = wp;
195 
196 	while (bus->rirb.rp != wp) {
197 		bus->rirb.rp++;
198 		bus->rirb.rp %= AZX_MAX_RIRB_ENTRIES;
199 
200 		rp = bus->rirb.rp << 1; /* an RIRB entry is 8-bytes */
201 		res_ex = le32_to_cpu(bus->rirb.buf[rp + 1]);
202 		res = le32_to_cpu(bus->rirb.buf[rp]);
203 		addr = res_ex & 0xf;
204 		if (addr >= HDA_MAX_CODECS) {
205 			dev_err(bus->dev,
206 				"spurious response %#x:%#x, rp = %d, wp = %d",
207 				res, res_ex, bus->rirb.rp, wp);
208 			snd_BUG();
209 		} else if (res_ex & AZX_RIRB_EX_UNSOL_EV)
210 			snd_hdac_bus_queue_event(bus, res, res_ex);
211 		else if (bus->rirb.cmds[addr]) {
212 			bus->rirb.res[addr] = res;
213 			bus->rirb.cmds[addr]--;
214 		} else {
215 			dev_err_ratelimited(bus->dev,
216 				"spurious response %#x:%#x, last cmd=%#08x\n",
217 				res, res_ex, bus->last_cmd[addr]);
218 		}
219 	}
220 }
221 EXPORT_SYMBOL_GPL(snd_hdac_bus_update_rirb);
222 
223 /**
224  * snd_hdac_bus_get_response - receive a response via RIRB
225  * @bus: HD-audio core bus
226  * @addr: codec address
227  * @res: pointer to store the value, NULL when not needed
228  *
229  * Returns zero if a value is read, or a negative error code.
230  */
231 int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
232 			      unsigned int *res)
233 {
234 	unsigned long timeout;
235 	unsigned long loopcounter;
236 
237 	timeout = jiffies + msecs_to_jiffies(1000);
238 
239 	for (loopcounter = 0;; loopcounter++) {
240 		spin_lock_irq(&bus->reg_lock);
241 		if (!bus->rirb.cmds[addr]) {
242 			if (res)
243 				*res = bus->rirb.res[addr]; /* the last value */
244 			spin_unlock_irq(&bus->reg_lock);
245 			return 0;
246 		}
247 		spin_unlock_irq(&bus->reg_lock);
248 		if (time_after(jiffies, timeout))
249 			break;
250 		if (loopcounter > 3000)
251 			msleep(2); /* temporary workaround */
252 		else {
253 			udelay(10);
254 			cond_resched();
255 		}
256 	}
257 
258 	return -EIO;
259 }
260 EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);
261 
262 #define HDAC_MAX_CAPS 10
263 /**
264  * snd_hdac_bus_parse_capabilities - parse capability structure
265  * @bus: the pointer to bus object
266  *
267  * Returns 0 if successful, or a negative error code.
268  */
269 int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
270 {
271 	unsigned int cur_cap;
272 	unsigned int offset;
273 	unsigned int counter = 0;
274 
275 	offset = snd_hdac_chip_readw(bus, LLCH);
276 
277 	/* Lets walk the linked capabilities list */
278 	do {
279 		cur_cap = _snd_hdac_chip_readl(bus, offset);
280 
281 		dev_dbg(bus->dev, "Capability version: 0x%x\n",
282 			(cur_cap & AZX_CAP_HDR_VER_MASK) >> AZX_CAP_HDR_VER_OFF);
283 
284 		dev_dbg(bus->dev, "HDA capability ID: 0x%x\n",
285 			(cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF);
286 
287 		if (cur_cap == -1) {
288 			dev_dbg(bus->dev, "Invalid capability reg read\n");
289 			break;
290 		}
291 
292 		switch ((cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF) {
293 		case AZX_ML_CAP_ID:
294 			dev_dbg(bus->dev, "Found ML capability\n");
295 			bus->mlcap = bus->remap_addr + offset;
296 			break;
297 
298 		case AZX_GTS_CAP_ID:
299 			dev_dbg(bus->dev, "Found GTS capability offset=%x\n", offset);
300 			bus->gtscap = bus->remap_addr + offset;
301 			break;
302 
303 		case AZX_PP_CAP_ID:
304 			/* PP capability found, the Audio DSP is present */
305 			dev_dbg(bus->dev, "Found PP capability offset=%x\n", offset);
306 			bus->ppcap = bus->remap_addr + offset;
307 			break;
308 
309 		case AZX_SPB_CAP_ID:
310 			/* SPIB capability found, handler function */
311 			dev_dbg(bus->dev, "Found SPB capability\n");
312 			bus->spbcap = bus->remap_addr + offset;
313 			break;
314 
315 		case AZX_DRSM_CAP_ID:
316 			/* DMA resume  capability found, handler function */
317 			dev_dbg(bus->dev, "Found DRSM capability\n");
318 			bus->drsmcap = bus->remap_addr + offset;
319 			break;
320 
321 		default:
322 			dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
323 			cur_cap = 0;
324 			break;
325 		}
326 
327 		counter++;
328 
329 		if (counter > HDAC_MAX_CAPS) {
330 			dev_err(bus->dev, "We exceeded HDAC capabilities!!!\n");
331 			break;
332 		}
333 
334 		/* read the offset of next capability */
335 		offset = cur_cap & AZX_CAP_HDR_NXT_PTR_MASK;
336 
337 	} while (offset);
338 
339 	return 0;
340 }
341 EXPORT_SYMBOL_GPL(snd_hdac_bus_parse_capabilities);
342 
343 /*
344  * Lowlevel interface
345  */
346 
347 /**
348  * snd_hdac_bus_enter_link_reset - enter link reset
349  * @bus: HD-audio core bus
350  *
351  * Enter to the link reset state.
352  */
353 void snd_hdac_bus_enter_link_reset(struct hdac_bus *bus)
354 {
355 	unsigned long timeout;
356 
357 	/* reset controller */
358 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_RESET, 0);
359 
360 	timeout = jiffies + msecs_to_jiffies(100);
361 	while ((snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET) &&
362 	       time_before(jiffies, timeout))
363 		usleep_range(500, 1000);
364 }
365 EXPORT_SYMBOL_GPL(snd_hdac_bus_enter_link_reset);
366 
367 /**
368  * snd_hdac_bus_exit_link_reset - exit link reset
369  * @bus: HD-audio core bus
370  *
371  * Exit from the link reset state.
372  */
373 void snd_hdac_bus_exit_link_reset(struct hdac_bus *bus)
374 {
375 	unsigned long timeout;
376 
377 	snd_hdac_chip_updateb(bus, GCTL, 0, AZX_GCTL_RESET);
378 
379 	timeout = jiffies + msecs_to_jiffies(100);
380 	while (!snd_hdac_chip_readb(bus, GCTL) && time_before(jiffies, timeout))
381 		usleep_range(500, 1000);
382 }
383 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit_link_reset);
384 
385 /* reset codec link */
386 static int azx_reset(struct hdac_bus *bus, bool full_reset)
387 {
388 	if (!full_reset)
389 		goto skip_reset;
390 
391 	/* clear STATESTS */
392 	snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
393 
394 	/* reset controller */
395 	snd_hdac_bus_enter_link_reset(bus);
396 
397 	/* delay for >= 100us for codec PLL to settle per spec
398 	 * Rev 0.9 section 5.5.1
399 	 */
400 	usleep_range(500, 1000);
401 
402 	/* Bring controller out of reset */
403 	snd_hdac_bus_exit_link_reset(bus);
404 
405 	/* Brent Chartrand said to wait >= 540us for codecs to initialize */
406 	usleep_range(1000, 1200);
407 
408  skip_reset:
409 	/* check to see if controller is ready */
410 	if (!snd_hdac_chip_readb(bus, GCTL)) {
411 		dev_dbg(bus->dev, "azx_reset: controller not ready!\n");
412 		return -EBUSY;
413 	}
414 
415 	/* Accept unsolicited responses */
416 	snd_hdac_chip_updatel(bus, GCTL, 0, AZX_GCTL_UNSOL);
417 
418 	/* detect codecs */
419 	if (!bus->codec_mask) {
420 		bus->codec_mask = snd_hdac_chip_readw(bus, STATESTS);
421 		dev_dbg(bus->dev, "codec_mask = 0x%lx\n", bus->codec_mask);
422 	}
423 
424 	return 0;
425 }
426 
427 /* enable interrupts */
428 static void azx_int_enable(struct hdac_bus *bus)
429 {
430 	/* enable controller CIE and GIE */
431 	snd_hdac_chip_updatel(bus, INTCTL, 0, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN);
432 }
433 
434 /* disable interrupts */
435 static void azx_int_disable(struct hdac_bus *bus)
436 {
437 	struct hdac_stream *azx_dev;
438 
439 	/* disable interrupts in stream descriptor */
440 	list_for_each_entry(azx_dev, &bus->stream_list, list)
441 		snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_INT_MASK, 0);
442 
443 	/* disable SIE for all streams */
444 	snd_hdac_chip_writeb(bus, INTCTL, 0);
445 
446 	/* disable controller CIE and GIE */
447 	snd_hdac_chip_updatel(bus, INTCTL, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN, 0);
448 }
449 
450 /* clear interrupts */
451 static void azx_int_clear(struct hdac_bus *bus)
452 {
453 	struct hdac_stream *azx_dev;
454 
455 	/* clear stream status */
456 	list_for_each_entry(azx_dev, &bus->stream_list, list)
457 		snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
458 
459 	/* clear STATESTS */
460 	snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
461 
462 	/* clear rirb status */
463 	snd_hdac_chip_writeb(bus, RIRBSTS, RIRB_INT_MASK);
464 
465 	/* clear int status */
466 	snd_hdac_chip_writel(bus, INTSTS, AZX_INT_CTRL_EN | AZX_INT_ALL_STREAM);
467 }
468 
469 /**
470  * snd_hdac_bus_init_chip - reset and start the controller registers
471  * @bus: HD-audio core bus
472  * @full_reset: Do full reset
473  */
474 bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset)
475 {
476 	if (bus->chip_init)
477 		return false;
478 
479 	/* reset controller */
480 	azx_reset(bus, full_reset);
481 
482 	/* initialize interrupts */
483 	azx_int_clear(bus);
484 	azx_int_enable(bus);
485 
486 	/* initialize the codec command I/O */
487 	snd_hdac_bus_init_cmd_io(bus);
488 
489 	/* program the position buffer */
490 	if (bus->use_posbuf && bus->posbuf.addr) {
491 		snd_hdac_chip_writel(bus, DPLBASE, (u32)bus->posbuf.addr);
492 		snd_hdac_chip_writel(bus, DPUBASE, upper_32_bits(bus->posbuf.addr));
493 	}
494 
495 	bus->chip_init = true;
496 	return true;
497 }
498 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_chip);
499 
500 /**
501  * snd_hdac_bus_stop_chip - disable the whole IRQ and I/Os
502  * @bus: HD-audio core bus
503  */
504 void snd_hdac_bus_stop_chip(struct hdac_bus *bus)
505 {
506 	if (!bus->chip_init)
507 		return;
508 
509 	/* disable interrupts */
510 	azx_int_disable(bus);
511 	azx_int_clear(bus);
512 
513 	/* disable CORB/RIRB */
514 	snd_hdac_bus_stop_cmd_io(bus);
515 
516 	/* disable position buffer */
517 	if (bus->posbuf.addr) {
518 		snd_hdac_chip_writel(bus, DPLBASE, 0);
519 		snd_hdac_chip_writel(bus, DPUBASE, 0);
520 	}
521 
522 	bus->chip_init = false;
523 }
524 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_chip);
525 
526 /**
527  * snd_hdac_bus_handle_stream_irq - interrupt handler for streams
528  * @bus: HD-audio core bus
529  * @status: INTSTS register value
530  * @ask: callback to be called for woken streams
531  *
532  * Returns the bits of handled streams, or zero if no stream is handled.
533  */
534 int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
535 				    void (*ack)(struct hdac_bus *,
536 						struct hdac_stream *))
537 {
538 	struct hdac_stream *azx_dev;
539 	u8 sd_status;
540 	int handled = 0;
541 
542 	list_for_each_entry(azx_dev, &bus->stream_list, list) {
543 		if (status & azx_dev->sd_int_sta_mask) {
544 			sd_status = snd_hdac_stream_readb(azx_dev, SD_STS);
545 			snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
546 			handled |= 1 << azx_dev->index;
547 			if (!azx_dev->substream || !azx_dev->running ||
548 			    !(sd_status & SD_INT_COMPLETE))
549 				continue;
550 			if (ack)
551 				ack(bus, azx_dev);
552 		}
553 	}
554 	return handled;
555 }
556 EXPORT_SYMBOL_GPL(snd_hdac_bus_handle_stream_irq);
557 
558 /**
559  * snd_hdac_bus_alloc_stream_pages - allocate BDL and other buffers
560  * @bus: HD-audio core bus
561  *
562  * Call this after assigning the all streams.
563  * Returns zero for success, or a negative error code.
564  */
565 int snd_hdac_bus_alloc_stream_pages(struct hdac_bus *bus)
566 {
567 	struct hdac_stream *s;
568 	int num_streams = 0;
569 	int err;
570 
571 	list_for_each_entry(s, &bus->stream_list, list) {
572 		/* allocate memory for the BDL for each stream */
573 		err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
574 						   BDL_SIZE, &s->bdl);
575 		num_streams++;
576 		if (err < 0)
577 			return -ENOMEM;
578 	}
579 
580 	if (WARN_ON(!num_streams))
581 		return -EINVAL;
582 	/* allocate memory for the position buffer */
583 	err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
584 					   num_streams * 8, &bus->posbuf);
585 	if (err < 0)
586 		return -ENOMEM;
587 	list_for_each_entry(s, &bus->stream_list, list)
588 		s->posbuf = (__le32 *)(bus->posbuf.area + s->index * 8);
589 
590 	/* single page (at least 4096 bytes) must suffice for both ringbuffes */
591 	return bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
592 					    PAGE_SIZE, &bus->rb);
593 }
594 EXPORT_SYMBOL_GPL(snd_hdac_bus_alloc_stream_pages);
595 
596 /**
597  * snd_hdac_bus_free_stream_pages - release BDL and other buffers
598  * @bus: HD-audio core bus
599  */
600 void snd_hdac_bus_free_stream_pages(struct hdac_bus *bus)
601 {
602 	struct hdac_stream *s;
603 
604 	list_for_each_entry(s, &bus->stream_list, list) {
605 		if (s->bdl.area)
606 			bus->io_ops->dma_free_pages(bus, &s->bdl);
607 	}
608 
609 	if (bus->rb.area)
610 		bus->io_ops->dma_free_pages(bus, &bus->rb);
611 	if (bus->posbuf.area)
612 		bus->io_ops->dma_free_pages(bus, &bus->posbuf);
613 }
614 EXPORT_SYMBOL_GPL(snd_hdac_bus_free_stream_pages);
615