xref: /openbmc/linux/sound/hda/hdac_controller.c (revision 404e077a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HD-audio controller helpers
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/delay.h>
8 #include <linux/export.h>
9 #include <sound/core.h>
10 #include <sound/hdaudio.h>
11 #include <sound/hda_register.h>
12 #include "local.h"
13 
14 /* clear CORB read pointer properly */
15 static void azx_clear_corbrp(struct hdac_bus *bus)
16 {
17 	int timeout;
18 
19 	for (timeout = 1000; timeout > 0; timeout--) {
20 		if (snd_hdac_chip_readw(bus, CORBRP) & AZX_CORBRP_RST)
21 			break;
22 		udelay(1);
23 	}
24 	if (timeout <= 0)
25 		dev_err(bus->dev, "CORB reset timeout#1, CORBRP = %d\n",
26 			snd_hdac_chip_readw(bus, CORBRP));
27 
28 	snd_hdac_chip_writew(bus, CORBRP, 0);
29 	for (timeout = 1000; timeout > 0; timeout--) {
30 		if (snd_hdac_chip_readw(bus, CORBRP) == 0)
31 			break;
32 		udelay(1);
33 	}
34 	if (timeout <= 0)
35 		dev_err(bus->dev, "CORB reset timeout#2, CORBRP = %d\n",
36 			snd_hdac_chip_readw(bus, CORBRP));
37 }
38 
39 /**
40  * snd_hdac_bus_init_cmd_io - set up CORB/RIRB buffers
41  * @bus: HD-audio core bus
42  */
43 void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
44 {
45 	WARN_ON_ONCE(!bus->rb.area);
46 
47 	spin_lock_irq(&bus->reg_lock);
48 	/* CORB set up */
49 	bus->corb.addr = bus->rb.addr;
50 	bus->corb.buf = (__le32 *)bus->rb.area;
51 	snd_hdac_chip_writel(bus, CORBLBASE, (u32)bus->corb.addr);
52 	snd_hdac_chip_writel(bus, CORBUBASE, upper_32_bits(bus->corb.addr));
53 
54 	/* set the corb size to 256 entries (ULI requires explicitly) */
55 	snd_hdac_chip_writeb(bus, CORBSIZE, 0x02);
56 	/* set the corb write pointer to 0 */
57 	snd_hdac_chip_writew(bus, CORBWP, 0);
58 
59 	/* reset the corb hw read pointer */
60 	snd_hdac_chip_writew(bus, CORBRP, AZX_CORBRP_RST);
61 	if (!bus->corbrp_self_clear)
62 		azx_clear_corbrp(bus);
63 
64 	/* enable corb dma */
65 	snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
66 
67 	/* RIRB set up */
68 	bus->rirb.addr = bus->rb.addr + 2048;
69 	bus->rirb.buf = (__le32 *)(bus->rb.area + 2048);
70 	bus->rirb.wp = bus->rirb.rp = 0;
71 	memset(bus->rirb.cmds, 0, sizeof(bus->rirb.cmds));
72 	snd_hdac_chip_writel(bus, RIRBLBASE, (u32)bus->rirb.addr);
73 	snd_hdac_chip_writel(bus, RIRBUBASE, upper_32_bits(bus->rirb.addr));
74 
75 	/* set the rirb size to 256 entries (ULI requires explicitly) */
76 	snd_hdac_chip_writeb(bus, RIRBSIZE, 0x02);
77 	/* reset the rirb hw write pointer */
78 	snd_hdac_chip_writew(bus, RIRBWP, AZX_RIRBWP_RST);
79 	/* set N=1, get RIRB response interrupt for new entry */
80 	snd_hdac_chip_writew(bus, RINTCNT, 1);
81 	/* enable rirb dma and response irq */
82 	if (bus->not_use_interrupts)
83 		snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN);
84 	else
85 		snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);
86 	/* Accept unsolicited responses */
87 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, AZX_GCTL_UNSOL);
88 	spin_unlock_irq(&bus->reg_lock);
89 }
90 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
91 
92 /* wait for cmd dmas till they are stopped */
93 static void hdac_wait_for_cmd_dmas(struct hdac_bus *bus)
94 {
95 	unsigned long timeout;
96 
97 	timeout = jiffies + msecs_to_jiffies(100);
98 	while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
99 		&& time_before(jiffies, timeout))
100 		udelay(10);
101 
102 	timeout = jiffies + msecs_to_jiffies(100);
103 	while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
104 		&& time_before(jiffies, timeout))
105 		udelay(10);
106 }
107 
108 /**
109  * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
110  * @bus: HD-audio core bus
111  */
112 void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
113 {
114 	spin_lock_irq(&bus->reg_lock);
115 	/* disable ringbuffer DMAs */
116 	snd_hdac_chip_writeb(bus, RIRBCTL, 0);
117 	snd_hdac_chip_writeb(bus, CORBCTL, 0);
118 	spin_unlock_irq(&bus->reg_lock);
119 
120 	hdac_wait_for_cmd_dmas(bus);
121 
122 	spin_lock_irq(&bus->reg_lock);
123 	/* disable unsolicited responses */
124 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
125 	spin_unlock_irq(&bus->reg_lock);
126 }
127 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_cmd_io);
128 
129 static unsigned int azx_command_addr(u32 cmd)
130 {
131 	unsigned int addr = cmd >> 28;
132 
133 	if (snd_BUG_ON(addr >= HDA_MAX_CODECS))
134 		addr = 0;
135 	return addr;
136 }
137 
138 /**
139  * snd_hdac_bus_send_cmd - send a command verb via CORB
140  * @bus: HD-audio core bus
141  * @val: encoded verb value to send
142  *
143  * Returns zero for success or a negative error code.
144  */
145 int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
146 {
147 	unsigned int addr = azx_command_addr(val);
148 	unsigned int wp, rp;
149 
150 	spin_lock_irq(&bus->reg_lock);
151 
152 	bus->last_cmd[azx_command_addr(val)] = val;
153 
154 	/* add command to corb */
155 	wp = snd_hdac_chip_readw(bus, CORBWP);
156 	if (wp == 0xffff) {
157 		/* something wrong, controller likely turned to D3 */
158 		spin_unlock_irq(&bus->reg_lock);
159 		return -EIO;
160 	}
161 	wp++;
162 	wp %= AZX_MAX_CORB_ENTRIES;
163 
164 	rp = snd_hdac_chip_readw(bus, CORBRP);
165 	if (wp == rp) {
166 		/* oops, it's full */
167 		spin_unlock_irq(&bus->reg_lock);
168 		return -EAGAIN;
169 	}
170 
171 	bus->rirb.cmds[addr]++;
172 	bus->corb.buf[wp] = cpu_to_le32(val);
173 	snd_hdac_chip_writew(bus, CORBWP, wp);
174 
175 	spin_unlock_irq(&bus->reg_lock);
176 
177 	return 0;
178 }
179 EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
180 
181 #define AZX_RIRB_EX_UNSOL_EV	(1<<4)
182 
183 /**
184  * snd_hdac_bus_update_rirb - retrieve RIRB entries
185  * @bus: HD-audio core bus
186  *
187  * Usually called from interrupt handler.
188  * The caller needs bus->reg_lock spinlock before calling this.
189  */
190 void snd_hdac_bus_update_rirb(struct hdac_bus *bus)
191 {
192 	unsigned int rp, wp;
193 	unsigned int addr;
194 	u32 res, res_ex;
195 
196 	wp = snd_hdac_chip_readw(bus, RIRBWP);
197 	if (wp == 0xffff) {
198 		/* something wrong, controller likely turned to D3 */
199 		return;
200 	}
201 
202 	if (wp == bus->rirb.wp)
203 		return;
204 	bus->rirb.wp = wp;
205 
206 	while (bus->rirb.rp != wp) {
207 		bus->rirb.rp++;
208 		bus->rirb.rp %= AZX_MAX_RIRB_ENTRIES;
209 
210 		rp = bus->rirb.rp << 1; /* an RIRB entry is 8-bytes */
211 		res_ex = le32_to_cpu(bus->rirb.buf[rp + 1]);
212 		res = le32_to_cpu(bus->rirb.buf[rp]);
213 		addr = res_ex & 0xf;
214 		if (addr >= HDA_MAX_CODECS) {
215 			dev_err(bus->dev,
216 				"spurious response %#x:%#x, rp = %d, wp = %d",
217 				res, res_ex, bus->rirb.rp, wp);
218 			snd_BUG();
219 		} else if (res_ex & AZX_RIRB_EX_UNSOL_EV)
220 			snd_hdac_bus_queue_event(bus, res, res_ex);
221 		else if (bus->rirb.cmds[addr]) {
222 			bus->rirb.res[addr] = res;
223 			bus->rirb.cmds[addr]--;
224 			if (!bus->rirb.cmds[addr] &&
225 			    waitqueue_active(&bus->rirb_wq))
226 				wake_up(&bus->rirb_wq);
227 		} else {
228 			dev_err_ratelimited(bus->dev,
229 				"spurious response %#x:%#x, last cmd=%#08x\n",
230 				res, res_ex, bus->last_cmd[addr]);
231 		}
232 	}
233 }
234 EXPORT_SYMBOL_GPL(snd_hdac_bus_update_rirb);
235 
236 /**
237  * snd_hdac_bus_get_response - receive a response via RIRB
238  * @bus: HD-audio core bus
239  * @addr: codec address
240  * @res: pointer to store the value, NULL when not needed
241  *
242  * Returns zero if a value is read, or a negative error code.
243  */
244 int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
245 			      unsigned int *res)
246 {
247 	unsigned long timeout;
248 	unsigned long loopcounter;
249 	wait_queue_entry_t wait;
250 	bool warned = false;
251 
252 	init_wait_entry(&wait, 0);
253 	timeout = jiffies + msecs_to_jiffies(1000);
254 
255 	for (loopcounter = 0;; loopcounter++) {
256 		spin_lock_irq(&bus->reg_lock);
257 		if (!bus->polling_mode)
258 			prepare_to_wait(&bus->rirb_wq, &wait,
259 					TASK_UNINTERRUPTIBLE);
260 		if (bus->polling_mode)
261 			snd_hdac_bus_update_rirb(bus);
262 		if (!bus->rirb.cmds[addr]) {
263 			if (res)
264 				*res = bus->rirb.res[addr]; /* the last value */
265 			if (!bus->polling_mode)
266 				finish_wait(&bus->rirb_wq, &wait);
267 			spin_unlock_irq(&bus->reg_lock);
268 			return 0;
269 		}
270 		spin_unlock_irq(&bus->reg_lock);
271 		if (time_after(jiffies, timeout))
272 			break;
273 #define LOOP_COUNT_MAX	3000
274 		if (!bus->polling_mode) {
275 			schedule_timeout(msecs_to_jiffies(2));
276 		} else if (bus->needs_damn_long_delay ||
277 			   loopcounter > LOOP_COUNT_MAX) {
278 			if (loopcounter > LOOP_COUNT_MAX && !warned) {
279 				dev_dbg_ratelimited(bus->dev,
280 						    "too slow response, last cmd=%#08x\n",
281 						    bus->last_cmd[addr]);
282 				warned = true;
283 			}
284 			msleep(2); /* temporary workaround */
285 		} else {
286 			udelay(10);
287 			cond_resched();
288 		}
289 	}
290 
291 	if (!bus->polling_mode)
292 		finish_wait(&bus->rirb_wq, &wait);
293 
294 	return -EIO;
295 }
296 EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);
297 
298 #define HDAC_MAX_CAPS 10
299 /**
300  * snd_hdac_bus_parse_capabilities - parse capability structure
301  * @bus: the pointer to bus object
302  *
303  * Returns 0 if successful, or a negative error code.
304  */
305 int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
306 {
307 	unsigned int cur_cap;
308 	unsigned int offset;
309 	unsigned int counter = 0;
310 
311 	offset = snd_hdac_chip_readw(bus, LLCH);
312 
313 	/* Lets walk the linked capabilities list */
314 	do {
315 		cur_cap = _snd_hdac_chip_readl(bus, offset);
316 
317 		dev_dbg(bus->dev, "Capability version: 0x%x\n",
318 			(cur_cap & AZX_CAP_HDR_VER_MASK) >> AZX_CAP_HDR_VER_OFF);
319 
320 		dev_dbg(bus->dev, "HDA capability ID: 0x%x\n",
321 			(cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF);
322 
323 		if (cur_cap == -1) {
324 			dev_dbg(bus->dev, "Invalid capability reg read\n");
325 			break;
326 		}
327 
328 		switch ((cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF) {
329 		case AZX_ML_CAP_ID:
330 			dev_dbg(bus->dev, "Found ML capability\n");
331 			bus->mlcap = bus->remap_addr + offset;
332 			break;
333 
334 		case AZX_GTS_CAP_ID:
335 			dev_dbg(bus->dev, "Found GTS capability offset=%x\n", offset);
336 			bus->gtscap = bus->remap_addr + offset;
337 			break;
338 
339 		case AZX_PP_CAP_ID:
340 			/* PP capability found, the Audio DSP is present */
341 			dev_dbg(bus->dev, "Found PP capability offset=%x\n", offset);
342 			bus->ppcap = bus->remap_addr + offset;
343 			break;
344 
345 		case AZX_SPB_CAP_ID:
346 			/* SPIB capability found, handler function */
347 			dev_dbg(bus->dev, "Found SPB capability\n");
348 			bus->spbcap = bus->remap_addr + offset;
349 			break;
350 
351 		case AZX_DRSM_CAP_ID:
352 			/* DMA resume  capability found, handler function */
353 			dev_dbg(bus->dev, "Found DRSM capability\n");
354 			bus->drsmcap = bus->remap_addr + offset;
355 			break;
356 
357 		default:
358 			dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
359 			cur_cap = 0;
360 			break;
361 		}
362 
363 		counter++;
364 
365 		if (counter > HDAC_MAX_CAPS) {
366 			dev_err(bus->dev, "We exceeded HDAC capabilities!!!\n");
367 			break;
368 		}
369 
370 		/* read the offset of next capability */
371 		offset = cur_cap & AZX_CAP_HDR_NXT_PTR_MASK;
372 
373 	} while (offset);
374 
375 	return 0;
376 }
377 EXPORT_SYMBOL_GPL(snd_hdac_bus_parse_capabilities);
378 
379 /*
380  * Lowlevel interface
381  */
382 
383 /**
384  * snd_hdac_bus_enter_link_reset - enter link reset
385  * @bus: HD-audio core bus
386  *
387  * Enter to the link reset state.
388  */
389 void snd_hdac_bus_enter_link_reset(struct hdac_bus *bus)
390 {
391 	unsigned long timeout;
392 
393 	/* reset controller */
394 	snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_RESET, 0);
395 
396 	timeout = jiffies + msecs_to_jiffies(100);
397 	while ((snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET) &&
398 	       time_before(jiffies, timeout))
399 		usleep_range(500, 1000);
400 }
401 EXPORT_SYMBOL_GPL(snd_hdac_bus_enter_link_reset);
402 
403 /**
404  * snd_hdac_bus_exit_link_reset - exit link reset
405  * @bus: HD-audio core bus
406  *
407  * Exit from the link reset state.
408  */
409 void snd_hdac_bus_exit_link_reset(struct hdac_bus *bus)
410 {
411 	unsigned long timeout;
412 
413 	snd_hdac_chip_updateb(bus, GCTL, AZX_GCTL_RESET, AZX_GCTL_RESET);
414 
415 	timeout = jiffies + msecs_to_jiffies(100);
416 	while (!snd_hdac_chip_readb(bus, GCTL) && time_before(jiffies, timeout))
417 		usleep_range(500, 1000);
418 }
419 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit_link_reset);
420 
421 /* reset codec link */
422 int snd_hdac_bus_reset_link(struct hdac_bus *bus, bool full_reset)
423 {
424 	if (!full_reset)
425 		goto skip_reset;
426 
427 	/* clear STATESTS if not in reset */
428 	if (snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET)
429 		snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
430 
431 	/* reset controller */
432 	snd_hdac_bus_enter_link_reset(bus);
433 
434 	/* delay for >= 100us for codec PLL to settle per spec
435 	 * Rev 0.9 section 5.5.1
436 	 */
437 	usleep_range(500, 1000);
438 
439 	/* Bring controller out of reset */
440 	snd_hdac_bus_exit_link_reset(bus);
441 
442 	/* Brent Chartrand said to wait >= 540us for codecs to initialize */
443 	usleep_range(1000, 1200);
444 
445  skip_reset:
446 	/* check to see if controller is ready */
447 	if (!snd_hdac_chip_readb(bus, GCTL)) {
448 		dev_dbg(bus->dev, "controller not ready!\n");
449 		return -EBUSY;
450 	}
451 
452 	/* detect codecs */
453 	if (!bus->codec_mask) {
454 		bus->codec_mask = snd_hdac_chip_readw(bus, STATESTS);
455 		dev_dbg(bus->dev, "codec_mask = 0x%lx\n", bus->codec_mask);
456 	}
457 
458 	return 0;
459 }
460 EXPORT_SYMBOL_GPL(snd_hdac_bus_reset_link);
461 
462 /* enable interrupts */
463 static void azx_int_enable(struct hdac_bus *bus)
464 {
465 	/* enable controller CIE and GIE */
466 	snd_hdac_chip_updatel(bus, INTCTL,
467 			      AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN,
468 			      AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN);
469 }
470 
471 /* disable interrupts */
472 static void azx_int_disable(struct hdac_bus *bus)
473 {
474 	struct hdac_stream *azx_dev;
475 
476 	/* disable interrupts in stream descriptor */
477 	list_for_each_entry(azx_dev, &bus->stream_list, list)
478 		snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_INT_MASK, 0);
479 
480 	/* disable SIE for all streams & disable controller CIE and GIE */
481 	snd_hdac_chip_writel(bus, INTCTL, 0);
482 }
483 
484 /* clear interrupts */
485 static void azx_int_clear(struct hdac_bus *bus)
486 {
487 	struct hdac_stream *azx_dev;
488 
489 	/* clear stream status */
490 	list_for_each_entry(azx_dev, &bus->stream_list, list)
491 		snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
492 
493 	/* clear STATESTS */
494 	snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
495 
496 	/* clear rirb status */
497 	snd_hdac_chip_writeb(bus, RIRBSTS, RIRB_INT_MASK);
498 
499 	/* clear int status */
500 	snd_hdac_chip_writel(bus, INTSTS, AZX_INT_CTRL_EN | AZX_INT_ALL_STREAM);
501 }
502 
503 /**
504  * snd_hdac_bus_init_chip - reset and start the controller registers
505  * @bus: HD-audio core bus
506  * @full_reset: Do full reset
507  */
508 bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset)
509 {
510 	if (bus->chip_init)
511 		return false;
512 
513 	/* reset controller */
514 	snd_hdac_bus_reset_link(bus, full_reset);
515 
516 	/* clear interrupts */
517 	azx_int_clear(bus);
518 
519 	/* initialize the codec command I/O */
520 	snd_hdac_bus_init_cmd_io(bus);
521 
522 	/* enable interrupts after CORB/RIRB buffers are initialized above */
523 	azx_int_enable(bus);
524 
525 	/* program the position buffer */
526 	if (bus->use_posbuf && bus->posbuf.addr) {
527 		snd_hdac_chip_writel(bus, DPLBASE, (u32)bus->posbuf.addr);
528 		snd_hdac_chip_writel(bus, DPUBASE, upper_32_bits(bus->posbuf.addr));
529 	}
530 
531 	bus->chip_init = true;
532 
533 	return true;
534 }
535 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_chip);
536 
537 /**
538  * snd_hdac_bus_stop_chip - disable the whole IRQ and I/Os
539  * @bus: HD-audio core bus
540  */
541 void snd_hdac_bus_stop_chip(struct hdac_bus *bus)
542 {
543 	if (!bus->chip_init)
544 		return;
545 
546 	/* disable interrupts */
547 	azx_int_disable(bus);
548 	azx_int_clear(bus);
549 
550 	/* disable CORB/RIRB */
551 	snd_hdac_bus_stop_cmd_io(bus);
552 
553 	/* disable position buffer */
554 	if (bus->posbuf.addr) {
555 		snd_hdac_chip_writel(bus, DPLBASE, 0);
556 		snd_hdac_chip_writel(bus, DPUBASE, 0);
557 	}
558 
559 	bus->chip_init = false;
560 }
561 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_chip);
562 
563 /**
564  * snd_hdac_bus_handle_stream_irq - interrupt handler for streams
565  * @bus: HD-audio core bus
566  * @status: INTSTS register value
567  * @ack: callback to be called for woken streams
568  *
569  * Returns the bits of handled streams, or zero if no stream is handled.
570  */
571 int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
572 				    void (*ack)(struct hdac_bus *,
573 						struct hdac_stream *))
574 {
575 	struct hdac_stream *azx_dev;
576 	u8 sd_status;
577 	int handled = 0;
578 
579 	list_for_each_entry(azx_dev, &bus->stream_list, list) {
580 		if (status & azx_dev->sd_int_sta_mask) {
581 			sd_status = snd_hdac_stream_readb(azx_dev, SD_STS);
582 			snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
583 			handled |= 1 << azx_dev->index;
584 			if ((!azx_dev->substream && !azx_dev->cstream) ||
585 			    !azx_dev->running || !(sd_status & SD_INT_COMPLETE))
586 				continue;
587 			if (ack)
588 				ack(bus, azx_dev);
589 		}
590 	}
591 	return handled;
592 }
593 EXPORT_SYMBOL_GPL(snd_hdac_bus_handle_stream_irq);
594 
595 /**
596  * snd_hdac_bus_alloc_stream_pages - allocate BDL and other buffers
597  * @bus: HD-audio core bus
598  *
599  * Call this after assigning the all streams.
600  * Returns zero for success, or a negative error code.
601  */
602 int snd_hdac_bus_alloc_stream_pages(struct hdac_bus *bus)
603 {
604 	struct hdac_stream *s;
605 	int num_streams = 0;
606 	int dma_type = bus->dma_type ? bus->dma_type : SNDRV_DMA_TYPE_DEV;
607 	int err;
608 
609 	list_for_each_entry(s, &bus->stream_list, list) {
610 		/* allocate memory for the BDL for each stream */
611 		err = snd_dma_alloc_pages(dma_type, bus->dev,
612 					  BDL_SIZE, &s->bdl);
613 		num_streams++;
614 		if (err < 0)
615 			return -ENOMEM;
616 	}
617 
618 	if (WARN_ON(!num_streams))
619 		return -EINVAL;
620 	/* allocate memory for the position buffer */
621 	err = snd_dma_alloc_pages(dma_type, bus->dev,
622 				  num_streams * 8, &bus->posbuf);
623 	if (err < 0)
624 		return -ENOMEM;
625 	list_for_each_entry(s, &bus->stream_list, list)
626 		s->posbuf = (__le32 *)(bus->posbuf.area + s->index * 8);
627 
628 	/* single page (at least 4096 bytes) must suffice for both ringbuffes */
629 	return snd_dma_alloc_pages(dma_type, bus->dev, PAGE_SIZE, &bus->rb);
630 }
631 EXPORT_SYMBOL_GPL(snd_hdac_bus_alloc_stream_pages);
632 
633 /**
634  * snd_hdac_bus_free_stream_pages - release BDL and other buffers
635  * @bus: HD-audio core bus
636  */
637 void snd_hdac_bus_free_stream_pages(struct hdac_bus *bus)
638 {
639 	struct hdac_stream *s;
640 
641 	list_for_each_entry(s, &bus->stream_list, list) {
642 		if (s->bdl.area)
643 			snd_dma_free_pages(&s->bdl);
644 	}
645 
646 	if (bus->rb.area)
647 		snd_dma_free_pages(&bus->rb);
648 	if (bus->posbuf.area)
649 		snd_dma_free_pages(&bus->posbuf);
650 }
651 EXPORT_SYMBOL_GPL(snd_hdac_bus_free_stream_pages);
652 
653 /**
654  * snd_hdac_bus_link_power - power up/down codec link
655  * @codec: HD-audio device
656  * @enable: whether to power-up the link
657  */
658 void snd_hdac_bus_link_power(struct hdac_device *codec, bool enable)
659 {
660 	if (enable)
661 		set_bit(codec->addr, &codec->bus->codec_powered);
662 	else
663 		clear_bit(codec->addr, &codec->bus->codec_powered);
664 }
665 EXPORT_SYMBOL_GPL(snd_hdac_bus_link_power);
666