Merge tag 'irq-urgent-2023-08-26' of git://git.kernel.org/pub/scm/linux/kernel/git...
[platform/kernel/linux-rpi.git] / sound / hda / hdac_controller.c
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);