xref: /linux/drivers/media/pci/cx25821/cx25821-alsa.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  *  Driver for the Conexant CX25821 PCIe bridge
3  *
4  *  Copyright (C) 2009 Conexant Systems Inc.
5  *  Authors  <shu.lin@conexant.com>, <hiep.huynh@conexant.com>
6  *	Based on SAA713x ALSA driver and CX88 driver
7  *
8  *   This program is free software; you can redistribute it and/or modify
9  *   it under the terms of the GNU General Public License as published by
10  *   the Free Software Foundation, version 2
11  *
12  *   This program is distributed in the hope that it will be useful,
13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  *   GNU General Public License for more details.
16  *
17  */
18 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/device.h>
24 #include <linux/interrupt.h>
25 #include <linux/vmalloc.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/pci.h>
28 #include <linux/slab.h>
29 
30 #include <linux/delay.h>
31 #include <sound/core.h>
32 #include <sound/pcm.h>
33 #include <sound/pcm_params.h>
34 #include <sound/control.h>
35 #include <sound/initval.h>
36 #include <sound/tlv.h>
37 
38 #include "cx25821.h"
39 #include "cx25821-reg.h"
40 
41 #define AUDIO_SRAM_CHANNEL	SRAM_CH08
42 
43 #define dprintk(level, fmt, arg...)				\
44 do {								\
45 	if (debug >= level)					\
46 		pr_info("%s/1: " fmt, chip->dev->name, ##arg);	\
47 } while (0)
48 #define dprintk_core(level, fmt, arg...)				\
49 do {									\
50 	if (debug >= level)						\
51 		printk(KERN_DEBUG "%s/1: " fmt, chip->dev->name, ##arg); \
52 } while (0)
53 
54 /****************************************************************************
55 	Data type declarations - Can be moded to a header file later
56  ****************************************************************************/
57 
58 static int devno;
59 
60 struct cx25821_audio_buffer {
61 	unsigned int bpl;
62 	struct cx25821_riscmem risc;
63 	void			*vaddr;
64 	struct scatterlist	*sglist;
65 	int                     sglen;
66 	int                     nr_pages;
67 };
68 
69 struct cx25821_audio_dev {
70 	struct cx25821_dev *dev;
71 	struct cx25821_dmaqueue q;
72 
73 	/* pci i/o */
74 	struct pci_dev *pci;
75 
76 	/* audio controls */
77 	int irq;
78 
79 	struct snd_card *card;
80 
81 	unsigned long iobase;
82 	spinlock_t reg_lock;
83 	atomic_t count;
84 
85 	unsigned int dma_size;
86 	unsigned int period_size;
87 	unsigned int num_periods;
88 
89 	struct cx25821_audio_buffer *buf;
90 
91 	struct snd_pcm_substream *substream;
92 };
93 
94 
95 /****************************************************************************
96 			Module global static vars
97  ****************************************************************************/
98 
99 static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;	/* Index 0-MAX */
100 static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;	/* ID for this card */
101 static bool enable[SNDRV_CARDS] = SNDRV_DEFAULT_ENABLE_PNP;
102 
103 module_param_array(enable, bool, NULL, 0444);
104 MODULE_PARM_DESC(enable, "Enable cx25821 soundcard. default enabled.");
105 
106 module_param_array(index, int, NULL, 0444);
107 MODULE_PARM_DESC(index, "Index value for cx25821 capture interface(s).");
108 
109 /****************************************************************************
110 				Module macros
111  ****************************************************************************/
112 
113 MODULE_DESCRIPTION("ALSA driver module for cx25821 based capture cards");
114 MODULE_AUTHOR("Hiep Huynh");
115 MODULE_LICENSE("GPL");
116 MODULE_SUPPORTED_DEVICE("{{Conexant,25821}");	/* "{{Conexant,23881}," */
117 
118 static unsigned int debug;
119 module_param(debug, int, 0644);
120 MODULE_PARM_DESC(debug, "enable debug messages");
121 
122 /****************************************************************************
123 			Module specific funtions
124  ****************************************************************************/
125 /* Constants taken from cx88-reg.h */
126 #define AUD_INT_DN_RISCI1       (1 <<  0)
127 #define AUD_INT_UP_RISCI1       (1 <<  1)
128 #define AUD_INT_RDS_DN_RISCI1   (1 <<  2)
129 #define AUD_INT_DN_RISCI2       (1 <<  4)	/* yes, 3 is skipped */
130 #define AUD_INT_UP_RISCI2       (1 <<  5)
131 #define AUD_INT_RDS_DN_RISCI2   (1 <<  6)
132 #define AUD_INT_DN_SYNC         (1 << 12)
133 #define AUD_INT_UP_SYNC         (1 << 13)
134 #define AUD_INT_RDS_DN_SYNC     (1 << 14)
135 #define AUD_INT_OPC_ERR         (1 << 16)
136 #define AUD_INT_BER_IRQ         (1 << 20)
137 #define AUD_INT_MCHG_IRQ        (1 << 21)
138 #define GP_COUNT_CONTROL_RESET	0x3
139 
140 #define PCI_MSK_AUD_EXT   (1 <<  4)
141 #define PCI_MSK_AUD_INT   (1 <<  3)
142 
143 static int cx25821_alsa_dma_init(struct cx25821_audio_dev *chip, int nr_pages)
144 {
145 	struct cx25821_audio_buffer *buf = chip->buf;
146 	struct page *pg;
147 	int i;
148 
149 	buf->vaddr = vmalloc_32(nr_pages << PAGE_SHIFT);
150 	if (NULL == buf->vaddr) {
151 		dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
152 		return -ENOMEM;
153 	}
154 
155 	dprintk(1, "vmalloc is at addr 0x%p, size=%d\n",
156 				buf->vaddr,
157 				nr_pages << PAGE_SHIFT);
158 
159 	memset(buf->vaddr, 0, nr_pages << PAGE_SHIFT);
160 	buf->nr_pages = nr_pages;
161 
162 	buf->sglist = vzalloc(array_size(sizeof(*buf->sglist), buf->nr_pages));
163 	if (NULL == buf->sglist)
164 		goto vzalloc_err;
165 
166 	sg_init_table(buf->sglist, buf->nr_pages);
167 	for (i = 0; i < buf->nr_pages; i++) {
168 		pg = vmalloc_to_page(buf->vaddr + i * PAGE_SIZE);
169 		if (NULL == pg)
170 			goto vmalloc_to_page_err;
171 		sg_set_page(&buf->sglist[i], pg, PAGE_SIZE, 0);
172 	}
173 	return 0;
174 
175 vmalloc_to_page_err:
176 	vfree(buf->sglist);
177 	buf->sglist = NULL;
178 vzalloc_err:
179 	vfree(buf->vaddr);
180 	buf->vaddr = NULL;
181 	return -ENOMEM;
182 }
183 
184 static int cx25821_alsa_dma_map(struct cx25821_audio_dev *dev)
185 {
186 	struct cx25821_audio_buffer *buf = dev->buf;
187 
188 	buf->sglen = dma_map_sg(&dev->pci->dev, buf->sglist,
189 			buf->nr_pages, PCI_DMA_FROMDEVICE);
190 
191 	if (0 == buf->sglen) {
192 		pr_warn("%s: cx25821_alsa_map_sg failed\n", __func__);
193 		return -ENOMEM;
194 	}
195 	return 0;
196 }
197 
198 static int cx25821_alsa_dma_unmap(struct cx25821_audio_dev *dev)
199 {
200 	struct cx25821_audio_buffer *buf = dev->buf;
201 
202 	if (!buf->sglen)
203 		return 0;
204 
205 	dma_unmap_sg(&dev->pci->dev, buf->sglist, buf->sglen, PCI_DMA_FROMDEVICE);
206 	buf->sglen = 0;
207 	return 0;
208 }
209 
210 static int cx25821_alsa_dma_free(struct cx25821_audio_buffer *buf)
211 {
212 	vfree(buf->sglist);
213 	buf->sglist = NULL;
214 	vfree(buf->vaddr);
215 	buf->vaddr = NULL;
216 	return 0;
217 }
218 
219 /*
220  * BOARD Specific: Sets audio DMA
221  */
222 
223 static int _cx25821_start_audio_dma(struct cx25821_audio_dev *chip)
224 {
225 	struct cx25821_audio_buffer *buf = chip->buf;
226 	struct cx25821_dev *dev = chip->dev;
227 	const struct sram_channel *audio_ch =
228 	    &cx25821_sram_channels[AUDIO_SRAM_CHANNEL];
229 	u32 tmp = 0;
230 
231 	/* enable output on the GPIO 0 for the MCLK ADC (Audio) */
232 	cx25821_set_gpiopin_direction(chip->dev, 0, 0);
233 
234 	/* Make sure RISC/FIFO are off before changing FIFO/RISC settings */
235 	cx_clear(AUD_INT_DMA_CTL,
236 		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
237 
238 	/* setup fifo + format - out channel */
239 	cx25821_sram_channel_setup_audio(chip->dev, audio_ch, buf->bpl,
240 					 buf->risc.dma);
241 
242 	/* sets bpl size */
243 	cx_write(AUD_A_LNGTH, buf->bpl);
244 
245 	/* reset counter */
246 	/* GP_COUNT_CONTROL_RESET = 0x3 */
247 	cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
248 	atomic_set(&chip->count, 0);
249 
250 	/* Set the input mode to 16-bit */
251 	tmp = cx_read(AUD_A_CFG);
252 	cx_write(AUD_A_CFG, tmp | FLD_AUD_DST_PK_MODE | FLD_AUD_DST_ENABLE |
253 		 FLD_AUD_CLK_ENABLE);
254 
255 	/*
256 	pr_info("DEBUG: Start audio DMA, %d B/line, cmds_start(0x%x)= %d lines/FIFO, %d periods, %d byte buffer\n",
257 		buf->bpl, audio_ch->cmds_start,
258 		cx_read(audio_ch->cmds_start + 12)>>1,
259 		chip->num_periods, buf->bpl * chip->num_periods);
260 	*/
261 
262 	/* Enables corresponding bits at AUD_INT_STAT */
263 	cx_write(AUD_A_INT_MSK, FLD_AUD_DST_RISCI1 | FLD_AUD_DST_OF |
264 		 FLD_AUD_DST_SYNC | FLD_AUD_DST_OPC_ERR);
265 
266 	/* Clean any pending interrupt bits already set */
267 	cx_write(AUD_A_INT_STAT, ~0);
268 
269 	/* enable audio irqs */
270 	cx_set(PCI_INT_MSK, chip->dev->pci_irqmask | PCI_MSK_AUD_INT);
271 
272 	/* Turn on audio downstream fifo and risc enable 0x101 */
273 	tmp = cx_read(AUD_INT_DMA_CTL);
274 	cx_set(AUD_INT_DMA_CTL, tmp |
275 	       (FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN));
276 
277 	mdelay(100);
278 	return 0;
279 }
280 
281 /*
282  * BOARD Specific: Resets audio DMA
283  */
284 static int _cx25821_stop_audio_dma(struct cx25821_audio_dev *chip)
285 {
286 	struct cx25821_dev *dev = chip->dev;
287 
288 	/* stop dma */
289 	cx_clear(AUD_INT_DMA_CTL,
290 		 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
291 
292 	/* disable irqs */
293 	cx_clear(PCI_INT_MSK, PCI_MSK_AUD_INT);
294 	cx_clear(AUD_A_INT_MSK, AUD_INT_OPC_ERR | AUD_INT_DN_SYNC |
295 		 AUD_INT_DN_RISCI2 | AUD_INT_DN_RISCI1);
296 
297 	return 0;
298 }
299 
300 #define MAX_IRQ_LOOP 50
301 
302 /*
303  * BOARD Specific: IRQ dma bits
304  */
305 static char *cx25821_aud_irqs[32] = {
306 	"dn_risci1", "up_risci1", "rds_dn_risc1",	/* 0-2 */
307 	NULL,						/* reserved */
308 	"dn_risci2", "up_risci2", "rds_dn_risc2",	/* 4-6 */
309 	NULL,						/* reserved */
310 	"dnf_of", "upf_uf", "rds_dnf_uf",		/* 8-10 */
311 	NULL,						/* reserved */
312 	"dn_sync", "up_sync", "rds_dn_sync",		/* 12-14 */
313 	NULL,						/* reserved */
314 	"opc_err", "par_err", "rip_err",		/* 16-18 */
315 	"pci_abort", "ber_irq", "mchg_irq"		/* 19-21 */
316 };
317 
318 /*
319  * BOARD Specific: Threats IRQ audio specific calls
320  */
321 static void cx25821_aud_irq(struct cx25821_audio_dev *chip, u32 status,
322 			    u32 mask)
323 {
324 	struct cx25821_dev *dev = chip->dev;
325 
326 	if (0 == (status & mask))
327 		return;
328 
329 	cx_write(AUD_A_INT_STAT, status);
330 	if (debug > 1 || (status & mask & ~0xff))
331 		cx25821_print_irqbits(dev->name, "irq aud", cx25821_aud_irqs,
332 				ARRAY_SIZE(cx25821_aud_irqs), status, mask);
333 
334 	/* risc op code error */
335 	if (status & AUD_INT_OPC_ERR) {
336 		pr_warn("WARNING %s/1: Audio risc op code error\n", dev->name);
337 
338 		cx_clear(AUD_INT_DMA_CTL,
339 			 FLD_AUD_DST_A_RISC_EN | FLD_AUD_DST_A_FIFO_EN);
340 		cx25821_sram_channel_dump_audio(dev,
341 				&cx25821_sram_channels[AUDIO_SRAM_CHANNEL]);
342 	}
343 	if (status & AUD_INT_DN_SYNC) {
344 		pr_warn("WARNING %s: Downstream sync error!\n", dev->name);
345 		cx_write(AUD_A_GPCNT_CTL, GP_COUNT_CONTROL_RESET);
346 		return;
347 	}
348 
349 	/* risc1 downstream */
350 	if (status & AUD_INT_DN_RISCI1) {
351 		atomic_set(&chip->count, cx_read(AUD_A_GPCNT));
352 		snd_pcm_period_elapsed(chip->substream);
353 	}
354 }
355 
356 /*
357  * BOARD Specific: Handles IRQ calls
358  */
359 static irqreturn_t cx25821_irq(int irq, void *dev_id)
360 {
361 	struct cx25821_audio_dev *chip = dev_id;
362 	struct cx25821_dev *dev = chip->dev;
363 	u32 status, pci_status;
364 	u32 audint_status, audint_mask;
365 	int loop, handled = 0;
366 
367 	audint_status = cx_read(AUD_A_INT_STAT);
368 	audint_mask = cx_read(AUD_A_INT_MSK);
369 	status = cx_read(PCI_INT_STAT);
370 
371 	for (loop = 0; loop < 1; loop++) {
372 		status = cx_read(PCI_INT_STAT);
373 		if (0 == status) {
374 			status = cx_read(PCI_INT_STAT);
375 			audint_status = cx_read(AUD_A_INT_STAT);
376 			audint_mask = cx_read(AUD_A_INT_MSK);
377 
378 			if (status) {
379 				handled = 1;
380 				cx_write(PCI_INT_STAT, status);
381 
382 				cx25821_aud_irq(chip, audint_status,
383 						audint_mask);
384 				break;
385 			} else {
386 				goto out;
387 			}
388 		}
389 
390 		handled = 1;
391 		cx_write(PCI_INT_STAT, status);
392 
393 		cx25821_aud_irq(chip, audint_status, audint_mask);
394 	}
395 
396 	pci_status = cx_read(PCI_INT_STAT);
397 
398 	if (handled)
399 		cx_write(PCI_INT_STAT, pci_status);
400 
401 out:
402 	return IRQ_RETVAL(handled);
403 }
404 
405 static int dsp_buffer_free(struct cx25821_audio_dev *chip)
406 {
407 	struct cx25821_riscmem *risc = &chip->buf->risc;
408 
409 	BUG_ON(!chip->dma_size);
410 
411 	dprintk(2, "Freeing buffer\n");
412 	cx25821_alsa_dma_unmap(chip);
413 	cx25821_alsa_dma_free(chip->buf);
414 	pci_free_consistent(chip->pci, risc->size, risc->cpu, risc->dma);
415 	kfree(chip->buf);
416 
417 	chip->buf = NULL;
418 	chip->dma_size = 0;
419 
420 	return 0;
421 }
422 
423 /****************************************************************************
424 				ALSA PCM Interface
425  ****************************************************************************/
426 
427 /*
428  * Digital hardware definition
429  */
430 #define DEFAULT_FIFO_SIZE	384
431 static const struct snd_pcm_hardware snd_cx25821_digital_hw = {
432 	.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
433 		SNDRV_PCM_INFO_BLOCK_TRANSFER | SNDRV_PCM_INFO_MMAP_VALID,
434 	.formats = SNDRV_PCM_FMTBIT_S16_LE,
435 
436 	.rates = SNDRV_PCM_RATE_48000,
437 	.rate_min = 48000,
438 	.rate_max = 48000,
439 	.channels_min = 2,
440 	.channels_max = 2,
441 	/* Analog audio output will be full of clicks and pops if there
442 	   are not exactly four lines in the SRAM FIFO buffer.  */
443 	.period_bytes_min = DEFAULT_FIFO_SIZE / 3,
444 	.period_bytes_max = DEFAULT_FIFO_SIZE / 3,
445 	.periods_min = 1,
446 	.periods_max = AUDIO_LINE_SIZE,
447 	/* 128 * 128 = 16384 = 1024 * 16 */
448 	.buffer_bytes_max = (AUDIO_LINE_SIZE * AUDIO_LINE_SIZE),
449 };
450 
451 /*
452  * audio pcm capture open callback
453  */
454 static int snd_cx25821_pcm_open(struct snd_pcm_substream *substream)
455 {
456 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
457 	struct snd_pcm_runtime *runtime = substream->runtime;
458 	int err;
459 	unsigned int bpl = 0;
460 
461 	if (!chip) {
462 		pr_err("DEBUG: cx25821 can't find device struct. Can't proceed with open\n");
463 		return -ENODEV;
464 	}
465 
466 	err = snd_pcm_hw_constraint_pow2(runtime, 0,
467 					 SNDRV_PCM_HW_PARAM_PERIODS);
468 	if (err < 0)
469 		goto _error;
470 
471 	chip->substream = substream;
472 
473 	runtime->hw = snd_cx25821_digital_hw;
474 
475 	if (cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size !=
476 	    DEFAULT_FIFO_SIZE) {
477 		/* since there are 3 audio Clusters */
478 		bpl = cx25821_sram_channels[AUDIO_SRAM_CHANNEL].fifo_size / 3;
479 		bpl &= ~7;	/* must be multiple of 8 */
480 
481 		if (bpl > AUDIO_LINE_SIZE)
482 			bpl = AUDIO_LINE_SIZE;
483 
484 		runtime->hw.period_bytes_min = bpl;
485 		runtime->hw.period_bytes_max = bpl;
486 	}
487 
488 	return 0;
489 _error:
490 	dprintk(1, "Error opening PCM!\n");
491 	return err;
492 }
493 
494 /*
495  * audio close callback
496  */
497 static int snd_cx25821_close(struct snd_pcm_substream *substream)
498 {
499 	return 0;
500 }
501 
502 /*
503  * hw_params callback
504  */
505 static int snd_cx25821_hw_params(struct snd_pcm_substream *substream,
506 				 struct snd_pcm_hw_params *hw_params)
507 {
508 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
509 	struct cx25821_audio_buffer *buf;
510 	int ret;
511 
512 	if (substream->runtime->dma_area) {
513 		dsp_buffer_free(chip);
514 		substream->runtime->dma_area = NULL;
515 	}
516 
517 	chip->period_size = params_period_bytes(hw_params);
518 	chip->num_periods = params_periods(hw_params);
519 	chip->dma_size = chip->period_size * params_periods(hw_params);
520 
521 	BUG_ON(!chip->dma_size);
522 	BUG_ON(chip->num_periods & (chip->num_periods - 1));
523 
524 	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
525 	if (NULL == buf)
526 		return -ENOMEM;
527 
528 	if (chip->period_size > AUDIO_LINE_SIZE)
529 		chip->period_size = AUDIO_LINE_SIZE;
530 
531 	buf->bpl = chip->period_size;
532 	chip->buf = buf;
533 
534 	ret = cx25821_alsa_dma_init(chip,
535 			(PAGE_ALIGN(chip->dma_size) >> PAGE_SHIFT));
536 	if (ret < 0)
537 		goto error;
538 
539 	ret = cx25821_alsa_dma_map(chip);
540 	if (ret < 0)
541 		goto error;
542 
543 	ret = cx25821_risc_databuffer_audio(chip->pci, &buf->risc, buf->sglist,
544 			chip->period_size, chip->num_periods, 1);
545 	if (ret < 0) {
546 		pr_info("DEBUG: ERROR after cx25821_risc_databuffer_audio()\n");
547 		goto error;
548 	}
549 
550 	/* Loop back to start of program */
551 	buf->risc.jmp[0] = cpu_to_le32(RISC_JUMP | RISC_IRQ1 | RISC_CNT_INC);
552 	buf->risc.jmp[1] = cpu_to_le32(buf->risc.dma);
553 	buf->risc.jmp[2] = cpu_to_le32(0);	/* bits 63-32 */
554 
555 	substream->runtime->dma_area = chip->buf->vaddr;
556 	substream->runtime->dma_bytes = chip->dma_size;
557 	substream->runtime->dma_addr = 0;
558 
559 	return 0;
560 
561 error:
562 	chip->buf = NULL;
563 	kfree(buf);
564 	return ret;
565 }
566 
567 /*
568  * hw free callback
569  */
570 static int snd_cx25821_hw_free(struct snd_pcm_substream *substream)
571 {
572 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
573 
574 	if (substream->runtime->dma_area) {
575 		dsp_buffer_free(chip);
576 		substream->runtime->dma_area = NULL;
577 	}
578 
579 	return 0;
580 }
581 
582 /*
583  * prepare callback
584  */
585 static int snd_cx25821_prepare(struct snd_pcm_substream *substream)
586 {
587 	return 0;
588 }
589 
590 /*
591  * trigger callback
592  */
593 static int snd_cx25821_card_trigger(struct snd_pcm_substream *substream,
594 				    int cmd)
595 {
596 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
597 	int err = 0;
598 
599 	/* Local interrupts are already disabled by ALSA */
600 	spin_lock(&chip->reg_lock);
601 
602 	switch (cmd) {
603 	case SNDRV_PCM_TRIGGER_START:
604 		err = _cx25821_start_audio_dma(chip);
605 		break;
606 	case SNDRV_PCM_TRIGGER_STOP:
607 		err = _cx25821_stop_audio_dma(chip);
608 		break;
609 	default:
610 		err = -EINVAL;
611 		break;
612 	}
613 
614 	spin_unlock(&chip->reg_lock);
615 
616 	return err;
617 }
618 
619 /*
620  * pointer callback
621  */
622 static snd_pcm_uframes_t snd_cx25821_pointer(struct snd_pcm_substream
623 					     *substream)
624 {
625 	struct cx25821_audio_dev *chip = snd_pcm_substream_chip(substream);
626 	struct snd_pcm_runtime *runtime = substream->runtime;
627 	u16 count;
628 
629 	count = atomic_read(&chip->count);
630 
631 	return runtime->period_size * (count & (runtime->periods - 1));
632 }
633 
634 /*
635  * page callback (needed for mmap)
636  */
637 static struct page *snd_cx25821_page(struct snd_pcm_substream *substream,
638 				     unsigned long offset)
639 {
640 	void *pageptr = substream->runtime->dma_area + offset;
641 
642 	return vmalloc_to_page(pageptr);
643 }
644 
645 /*
646  * operators
647  */
648 static const struct snd_pcm_ops snd_cx25821_pcm_ops = {
649 	.open = snd_cx25821_pcm_open,
650 	.close = snd_cx25821_close,
651 	.ioctl = snd_pcm_lib_ioctl,
652 	.hw_params = snd_cx25821_hw_params,
653 	.hw_free = snd_cx25821_hw_free,
654 	.prepare = snd_cx25821_prepare,
655 	.trigger = snd_cx25821_card_trigger,
656 	.pointer = snd_cx25821_pointer,
657 	.page = snd_cx25821_page,
658 };
659 
660 /*
661  * ALSA create a PCM device:  Called when initializing the board.
662  * Sets up the name and hooks up the callbacks
663  */
664 static int snd_cx25821_pcm(struct cx25821_audio_dev *chip, int device,
665 			   char *name)
666 {
667 	struct snd_pcm *pcm;
668 	int err;
669 
670 	err = snd_pcm_new(chip->card, name, device, 0, 1, &pcm);
671 	if (err < 0) {
672 		pr_info("ERROR: FAILED snd_pcm_new() in %s\n", __func__);
673 		return err;
674 	}
675 	pcm->private_data = chip;
676 	pcm->info_flags = 0;
677 	strcpy(pcm->name, name);
678 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_cx25821_pcm_ops);
679 
680 	return 0;
681 }
682 
683 /****************************************************************************
684 			Basic Flow for Sound Devices
685  ****************************************************************************/
686 
687 /*
688  * PCI ID Table - 14f1:8801 and 14f1:8811 means function 1: Audio
689  * Only boards with eeprom and byte 1 at eeprom=1 have it
690  */
691 
692 static const struct pci_device_id __maybe_unused cx25821_audio_pci_tbl[] = {
693 	{0x14f1, 0x0920, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0},
694 	{0,}
695 };
696 
697 MODULE_DEVICE_TABLE(pci, cx25821_audio_pci_tbl);
698 
699 /*
700  * Alsa Constructor - Component probe
701  */
702 static int cx25821_audio_initdev(struct cx25821_dev *dev)
703 {
704 	struct snd_card *card;
705 	struct cx25821_audio_dev *chip;
706 	int err;
707 
708 	if (devno >= SNDRV_CARDS) {
709 		pr_info("DEBUG ERROR: devno >= SNDRV_CARDS %s\n", __func__);
710 		return -ENODEV;
711 	}
712 
713 	if (!enable[devno]) {
714 		++devno;
715 		pr_info("DEBUG ERROR: !enable[devno] %s\n", __func__);
716 		return -ENOENT;
717 	}
718 
719 	err = snd_card_new(&dev->pci->dev, index[devno], id[devno],
720 			   THIS_MODULE,
721 			   sizeof(struct cx25821_audio_dev), &card);
722 	if (err < 0) {
723 		pr_info("DEBUG ERROR: cannot create snd_card_new in %s\n",
724 			__func__);
725 		return err;
726 	}
727 
728 	strcpy(card->driver, "cx25821");
729 
730 	/* Card "creation" */
731 	chip = card->private_data;
732 	spin_lock_init(&chip->reg_lock);
733 
734 	chip->dev = dev;
735 	chip->card = card;
736 	chip->pci = dev->pci;
737 	chip->iobase = pci_resource_start(dev->pci, 0);
738 
739 	chip->irq = dev->pci->irq;
740 
741 	err = request_irq(dev->pci->irq, cx25821_irq,
742 			  IRQF_SHARED, chip->dev->name, chip);
743 
744 	if (err < 0) {
745 		pr_err("ERROR %s: can't get IRQ %d for ALSA\n", chip->dev->name,
746 			dev->pci->irq);
747 		goto error;
748 	}
749 
750 	err = snd_cx25821_pcm(chip, 0, "cx25821 Digital");
751 	if (err < 0) {
752 		pr_info("DEBUG ERROR: cannot create snd_cx25821_pcm %s\n",
753 			__func__);
754 		goto error;
755 	}
756 
757 	strcpy(card->shortname, "cx25821");
758 	sprintf(card->longname, "%s at 0x%lx irq %d", chip->dev->name,
759 		chip->iobase, chip->irq);
760 	strcpy(card->mixername, "CX25821");
761 
762 	pr_info("%s/%i: ALSA support for cx25821 boards\n", card->driver,
763 		devno);
764 
765 	err = snd_card_register(card);
766 	if (err < 0) {
767 		pr_info("DEBUG ERROR: cannot register sound card %s\n",
768 			__func__);
769 		goto error;
770 	}
771 
772 	dev->card = card;
773 	devno++;
774 	return 0;
775 
776 error:
777 	snd_card_free(card);
778 	return err;
779 }
780 
781 /****************************************************************************
782 				LINUX MODULE INIT
783  ****************************************************************************/
784 
785 static int cx25821_alsa_exit_callback(struct device *dev, void *data)
786 {
787 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
788 	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);
789 
790 	snd_card_free(cxdev->card);
791 	return 0;
792 }
793 
794 static void cx25821_audio_fini(void)
795 {
796 	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);
797 	int ret;
798 
799 	ret = driver_for_each_device(drv, NULL, NULL, cx25821_alsa_exit_callback);
800 	if (ret)
801 		pr_err("%s failed to find a cx25821 driver.\n", __func__);
802 }
803 
804 static int cx25821_alsa_init_callback(struct device *dev, void *data)
805 {
806 	struct v4l2_device *v4l2_dev = dev_get_drvdata(dev);
807 	struct cx25821_dev *cxdev = get_cx25821(v4l2_dev);
808 
809 	cx25821_audio_initdev(cxdev);
810 	return 0;
811 }
812 
813 /*
814  * Module initializer
815  *
816  * Loops through present saa7134 cards, and assigns an ALSA device
817  * to each one
818  *
819  */
820 static int cx25821_alsa_init(void)
821 {
822 	struct device_driver *drv = driver_find("cx25821", &pci_bus_type);
823 
824 	return driver_for_each_device(drv, NULL, NULL, cx25821_alsa_init_callback);
825 
826 }
827 
828 late_initcall(cx25821_alsa_init);
829 module_exit(cx25821_audio_fini);
830