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