drivers/media/pci/tw686x/tw686x-audio.c - linux/kernel/git/bpf/bpf - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
  *
  * Based on the audio support from the tw6869 driver:
  * Copyright 2015 www.starterkit.ru <info@starterkit.ru>
  *
  * Based on:
  * Driver for Intersil|Techwell TW6869 based DVR cards
  * (c) 2011-12 liran <jli11@intersil.com> [Intersil|Techwell China]
  */

 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kmod.h>
 #include <linux/mutex.h>
 #include <linux/pci.h>
 #include <linux/delay.h>

 #include <sound/core.h>
 #include <sound/initval.h>
 #include <sound/pcm.h>
 #include <sound/control.h>
 #include "tw686x.h"
 #include "tw686x-regs.h"

 #define AUDIO_CHANNEL_OFFSET 8

 void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
 		      unsigned int pb_status)
 {
 	unsigned long flags;
 	unsigned int ch, pb;

 	for_each_set_bit(ch, &requests, max_channels(dev)) {
 		struct tw686x_audio_channel *ac = &dev->audio_channels[ch];
 		struct tw686x_audio_buf *done = NULL;
 		struct tw686x_audio_buf *next = NULL;
 		struct tw686x_dma_desc *desc;

 		pb = !!(pb_status & BIT(AUDIO_CHANNEL_OFFSET + ch));

 		spin_lock_irqsave(&ac->lock, flags);

 		/* Sanity check */
 		if (!ac->ss || !ac->curr_bufs[0] || !ac->curr_bufs[1]) {
 			spin_unlock_irqrestore(&ac->lock, flags);
 			continue;
 		}

 		if (!list_empty(&ac->buf_list)) {
 			next = list_first_entry(&ac->buf_list,
 					struct tw686x_audio_buf, list);
 			list_move_tail(&next->list, &ac->buf_list);
 			done = ac->curr_bufs[!pb];
 			ac->curr_bufs[pb] = next;
 		}
 		spin_unlock_irqrestore(&ac->lock, flags);

 		if (!done || !next)
 			continue;
 		/*
 		 * Checking for a non-nil dma_desc[pb]->virt buffer is
 		 * the same as checking for memcpy DMA mode.
 		 */
 		desc = &ac->dma_descs[pb];
 		if (desc->virt) {
 			memcpy(done->virt, desc->virt,
 			       dev->period_size);
 		} else {
 			u32 reg = pb ? ADMA_B_ADDR[ch] : ADMA_P_ADDR[ch];
 			reg_write(dev, reg, next->dma);
 		}
 		ac->ptr = done->dma - ac->buf[0].dma;
 		snd_pcm_period_elapsed(ac->ss);
 	}
 }

 /*
  * Audio parameters are global and shared among all
  * capture channels. The driver prevents changes to
  * the parameters if any audio channel is capturing.
  */
 static const struct snd_pcm_hardware tw686x_capture_hw = {
 	.info			= (SNDRV_PCM_INFO_MMAP |
 				   SNDRV_PCM_INFO_INTERLEAVED |
 				   SNDRV_PCM_INFO_BLOCK_TRANSFER |
 				   SNDRV_PCM_INFO_MMAP_VALID),
 	.formats		= SNDRV_PCM_FMTBIT_S16_LE,
 	.rates			= SNDRV_PCM_RATE_8000_48000,
 	.rate_min		= 8000,
 	.rate_max		= 48000,
 	.channels_min		= 1,
 	.channels_max		= 1,
 	.buffer_bytes_max	= TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
 	.period_bytes_min	= AUDIO_DMA_SIZE_MIN,
 	.period_bytes_max	= AUDIO_DMA_SIZE_MAX,
 	.periods_min		= TW686X_AUDIO_PERIODS_MIN,
 	.periods_max		= TW686X_AUDIO_PERIODS_MAX,
 };

 static int tw686x_pcm_open(struct snd_pcm_substream *ss)
 {
 	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
 	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
 	struct snd_pcm_runtime *rt = ss->runtime;
 	int err;

 	ac->ss = ss;
 	rt->hw = tw686x_capture_hw;

 	err = snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
 	if (err < 0)
 		return err;

 	return 0;
 }

 static int tw686x_pcm_close(struct snd_pcm_substream *ss)
 {
 	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
 	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];

 	ac->ss = NULL;
 	return 0;
 }

 static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
 {
 	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
 	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
 	struct snd_pcm_runtime *rt = ss->runtime;
 	unsigned int period_size = snd_pcm_lib_period_bytes(ss);
 	struct tw686x_audio_buf *p_buf, *b_buf;
 	unsigned long flags;
 	int i;

 	spin_lock_irqsave(&dev->lock, flags);
 	/*
 	 * Given the audio parameters are global (i.e. shared across
 	 * DMA channels), we need to check new params are allowed.
 	 */
 	if (((dev->audio_rate != rt->rate) ||
 	     (dev->period_size != period_size)) && dev->audio_enabled)
 		goto err_audio_busy;

 	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
 	spin_unlock_irqrestore(&dev->lock, flags);

 	if (dev->audio_rate != rt->rate) {
 		u32 reg;

 		dev->audio_rate = rt->rate;
 		reg = ((125000000 / rt->rate) << 16) +
 		       ((125000000 % rt->rate) << 16) / rt->rate;

 		reg_write(dev, AUDIO_CONTROL2, reg);
 	}

 	if (dev->period_size != period_size) {
 		u32 reg;

 		dev->period_size = period_size;
 		reg = reg_read(dev, AUDIO_CONTROL1);
 		reg &= ~(AUDIO_DMA_SIZE_MASK << AUDIO_DMA_SIZE_SHIFT);
 		reg |= period_size << AUDIO_DMA_SIZE_SHIFT;

 		reg_write(dev, AUDIO_CONTROL1, reg);
 	}

 	if (rt->periods < TW686X_AUDIO_PERIODS_MIN ||
 	    rt->periods > TW686X_AUDIO_PERIODS_MAX)
 		return -EINVAL;

 	spin_lock_irqsave(&ac->lock, flags);
 	INIT_LIST_HEAD(&ac->buf_list);

 	for (i = 0; i < rt->periods; i++) {
 		ac->buf[i].dma = rt->dma_addr + period_size * i;
 		ac->buf[i].virt = rt->dma_area + period_size * i;
 		INIT_LIST_HEAD(&ac->buf[i].list);
 		list_add_tail(&ac->buf[i].list, &ac->buf_list);
 	}

 	p_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
 	list_move_tail(&p_buf->list, &ac->buf_list);

 	b_buf =	list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
 	list_move_tail(&b_buf->list, &ac->buf_list);

 	ac->curr_bufs[0] = p_buf;
 	ac->curr_bufs[1] = b_buf;
 	ac->ptr = 0;

 	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY) {
 		reg_write(dev, ADMA_P_ADDR[ac->ch], p_buf->dma);
 		reg_write(dev, ADMA_B_ADDR[ac->ch], b_buf->dma);
 	}

 	spin_unlock_irqrestore(&ac->lock, flags);

 	return 0;

 err_audio_busy:
 	spin_unlock_irqrestore(&dev->lock, flags);
 	return -EBUSY;
 }

 static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
 {
 	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
 	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
 	unsigned long flags;
 	int err = 0;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
 			spin_lock_irqsave(&dev->lock, flags);
 			dev->audio_enabled = 1;
 			tw686x_enable_channel(dev,
 				AUDIO_CHANNEL_OFFSET + ac->ch);
 			spin_unlock_irqrestore(&dev->lock, flags);

 			mod_timer(&dev->dma_delay_timer,
 				  jiffies + msecs_to_jiffies(100));
 		} else {
 			err = -EIO;
 		}
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		spin_lock_irqsave(&dev->lock, flags);
 		dev->audio_enabled = 0;
 		tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
 		spin_unlock_irqrestore(&dev->lock, flags);

 		spin_lock_irqsave(&ac->lock, flags);
 		ac->curr_bufs[0] = NULL;
 		ac->curr_bufs[1] = NULL;
 		spin_unlock_irqrestore(&ac->lock, flags);
 		break;
 	default:
 		err = -EINVAL;
 	}
 	return err;
 }

 static snd_pcm_uframes_t tw686x_pcm_pointer(struct snd_pcm_substream *ss)
 {
 	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
 	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];

 	return bytes_to_frames(ss->runtime, ac->ptr);
 }

 static const struct snd_pcm_ops tw686x_pcm_ops = {
 	.open = tw686x_pcm_open,
 	.close = tw686x_pcm_close,
 	.prepare = tw686x_pcm_prepare,
 	.trigger = tw686x_pcm_trigger,
 	.pointer = tw686x_pcm_pointer,
 };

 static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
 {
 	struct snd_card *card = dev->snd_card;
 	struct snd_pcm *pcm;
 	struct snd_pcm_substream *ss;
 	unsigned int i;
 	int err;

 	err = snd_pcm_new(card, card->driver, 0, 0, max_channels(dev), &pcm);
 	if (err < 0)
 		return err;

 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tw686x_pcm_ops);
 	snd_pcm_chip(pcm) = dev;
 	pcm->info_flags = 0;
 	strscpy(pcm->name, "tw686x PCM", sizeof(pcm->name));

 	for (i = 0, ss = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
 	     ss; ss = ss->next, i++)
 		snprintf(ss->name, sizeof(ss->name), "vch%u audio", i);

 	snd_pcm_set_managed_buffer_all(pcm,
 				SNDRV_DMA_TYPE_DEV,
 				&dev->pci_dev->dev,
 				TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
 				TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX);
 	return 0;
 }

 static void tw686x_audio_dma_free(struct tw686x_dev *dev,
 				  struct tw686x_audio_channel *ac)
 {
 	int pb;

 	for (pb = 0; pb < 2; pb++) {
 		if (!ac->dma_descs[pb].virt)
 			continue;
 		pci_free_consistent(dev->pci_dev, ac->dma_descs[pb].size,
 				    ac->dma_descs[pb].virt,
 				    ac->dma_descs[pb].phys);
 		ac->dma_descs[pb].virt = NULL;
 	}
 }

 static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
 				  struct tw686x_audio_channel *ac)
 {
 	int pb;

 	/*
 	 * In the memcpy DMA mode we allocate a consistent buffer
 	 * and use it for the DMA capture. Otherwise, DMA
 	 * acts on the ALSA buffers as received in pcm_prepare.
 	 */
 	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY)
 		return 0;

 	for (pb = 0; pb < 2; pb++) {
 		u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
 		void *virt;

 		virt = pci_alloc_consistent(dev->pci_dev, AUDIO_DMA_SIZE_MAX,
 					    &ac->dma_descs[pb].phys);
 		if (!virt) {
 			dev_err(&dev->pci_dev->dev,
 				"dma%d: unable to allocate audio DMA %s-buffer\n",
 				ac->ch, pb ? "B" : "P");
 			return -ENOMEM;
 		}
 		ac->dma_descs[pb].virt = virt;
 		ac->dma_descs[pb].size = AUDIO_DMA_SIZE_MAX;
 		reg_write(dev, reg, ac->dma_descs[pb].phys);
 	}
 	return 0;
 }

 void tw686x_audio_free(struct tw686x_dev *dev)
 {
 	unsigned long flags;
 	u32 dma_ch_mask;
 	u32 dma_cmd;

 	spin_lock_irqsave(&dev->lock, flags);
 	dma_cmd = reg_read(dev, DMA_CMD);
 	dma_ch_mask = reg_read(dev, DMA_CHANNEL_ENABLE);
 	reg_write(dev, DMA_CMD, dma_cmd & ~0xff00);
 	reg_write(dev, DMA_CHANNEL_ENABLE, dma_ch_mask & ~0xff00);
 	spin_unlock_irqrestore(&dev->lock, flags);

 	if (!dev->snd_card)
 		return;
 	snd_card_free(dev->snd_card);
 	dev->snd_card = NULL;
 }

 int tw686x_audio_init(struct tw686x_dev *dev)
 {
 	struct pci_dev *pci_dev = dev->pci_dev;
 	struct snd_card *card;
 	int err, ch;

 	/* Enable external audio */
 	reg_write(dev, AUDIO_CONTROL1, BIT(0));

 	err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
 			   SNDRV_DEFAULT_STR1,
 			   THIS_MODULE, 0, &card);
 	if (err < 0)
 		return err;

 	dev->snd_card = card;
 	strscpy(card->driver, "tw686x", sizeof(card->driver));
 	strscpy(card->shortname, "tw686x", sizeof(card->shortname));
 	strscpy(card->longname, pci_name(pci_dev), sizeof(card->longname));
 	snd_card_set_dev(card, &pci_dev->dev);

 	for (ch = 0; ch < max_channels(dev); ch++) {
 		struct tw686x_audio_channel *ac;

 		ac = &dev->audio_channels[ch];
 		spin_lock_init(&ac->lock);
 		ac->dev = dev;
 		ac->ch = ch;

 		err = tw686x_audio_dma_alloc(dev, ac);
 		if (err < 0)
 			goto err_cleanup;
 	}

 	err = tw686x_snd_pcm_init(dev);
 	if (err < 0)
 		goto err_cleanup;

 	err = snd_card_register(card);
 	if (!err)
 		return 0;

 err_cleanup:
 	for (ch = 0; ch < max_channels(dev); ch++) {
 		if (!dev->audio_channels[ch].dev)
 			continue;
 		tw686x_audio_dma_free(dev, &dev->audio_channels[ch]);
 	}
 	snd_card_free(card);
 	dev->snd_card = NULL;
 	return err;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2015 VanguardiaSur - www.vanguardiasur.com.ar
	*
	* Based on the audio support from the tw6869 driver:
	* Copyright 2015 www.starterkit.ru <info@starterkit.ru>
	*
	* Based on:
	* Driver for Intersil\|Techwell TW6869 based DVR cards
	* (c) 2011-12 liran <jli11@intersil.com> [Intersil\|Techwell China]
	*/

	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/kmod.h>
	#include <linux/mutex.h>
	#include <linux/pci.h>
	#include <linux/delay.h>

	#include <sound/core.h>
	#include <sound/initval.h>
	#include <sound/pcm.h>
	#include <sound/control.h>
	#include "tw686x.h"
	#include "tw686x-regs.h"

	#define AUDIO_CHANNEL_OFFSET 8

	void tw686x_audio_irq(struct tw686x_dev *dev, unsigned long requests,
	unsigned int pb_status)
	{
	unsigned long flags;
	unsigned int ch, pb;

	for_each_set_bit(ch, &requests, max_channels(dev)) {
	struct tw686x_audio_channel *ac = &dev->audio_channels[ch];
	struct tw686x_audio_buf *done = NULL;
	struct tw686x_audio_buf *next = NULL;
	struct tw686x_dma_desc *desc;

	pb = !!(pb_status & BIT(AUDIO_CHANNEL_OFFSET + ch));

	spin_lock_irqsave(&ac->lock, flags);

	/* Sanity check */
	if (!ac->ss \|\| !ac->curr_bufs[0] \|\| !ac->curr_bufs[1]) {
	spin_unlock_irqrestore(&ac->lock, flags);
	continue;
	}

	if (!list_empty(&ac->buf_list)) {
	next = list_first_entry(&ac->buf_list,
	struct tw686x_audio_buf, list);
	list_move_tail(&next->list, &ac->buf_list);
	done = ac->curr_bufs[!pb];
	ac->curr_bufs[pb] = next;
	}
	spin_unlock_irqrestore(&ac->lock, flags);

	if (!done \|\| !next)
	continue;
	/*
	* Checking for a non-nil dma_desc[pb]->virt buffer is
	* the same as checking for memcpy DMA mode.
	*/
	desc = &ac->dma_descs[pb];
	if (desc->virt) {
	memcpy(done->virt, desc->virt,
	dev->period_size);
	} else {
	u32 reg = pb ? ADMA_B_ADDR[ch] : ADMA_P_ADDR[ch];
	reg_write(dev, reg, next->dma);
	}
	ac->ptr = done->dma - ac->buf[0].dma;
	snd_pcm_period_elapsed(ac->ss);
	}
	}

	/*
	* Audio parameters are global and shared among all
	* capture channels. The driver prevents changes to
	* the parameters if any audio channel is capturing.
	*/
	static const struct snd_pcm_hardware tw686x_capture_hw = {
	.info = (SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \|
	SNDRV_PCM_INFO_MMAP_VALID),
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	.rates = SNDRV_PCM_RATE_8000_48000,
	.rate_min = 8000,
	.rate_max = 48000,
	.channels_min = 1,
	.channels_max = 1,
	.buffer_bytes_max = TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
	.period_bytes_min = AUDIO_DMA_SIZE_MIN,
	.period_bytes_max = AUDIO_DMA_SIZE_MAX,
	.periods_min = TW686X_AUDIO_PERIODS_MIN,
	.periods_max = TW686X_AUDIO_PERIODS_MAX,
	};

	static int tw686x_pcm_open(struct snd_pcm_substream *ss)
	{
	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
	struct snd_pcm_runtime *rt = ss->runtime;
	int err;

	ac->ss = ss;
	rt->hw = tw686x_capture_hw;

	err = snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
	if (err < 0)
	return err;

	return 0;
	}

	static int tw686x_pcm_close(struct snd_pcm_substream *ss)
	{
	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];

	ac->ss = NULL;
	return 0;
	}

	static int tw686x_pcm_prepare(struct snd_pcm_substream *ss)
	{
	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
	struct snd_pcm_runtime *rt = ss->runtime;
	unsigned int period_size = snd_pcm_lib_period_bytes(ss);
	struct tw686x_audio_buf p_buf, b_buf;
	unsigned long flags;
	int i;

	spin_lock_irqsave(&dev->lock, flags);
	/*
	* Given the audio parameters are global (i.e. shared across
	* DMA channels), we need to check new params are allowed.
	*/
	if (((dev->audio_rate != rt->rate) \|\|
	(dev->period_size != period_size)) && dev->audio_enabled)
	goto err_audio_busy;

	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
	spin_unlock_irqrestore(&dev->lock, flags);

	if (dev->audio_rate != rt->rate) {
	u32 reg;

	dev->audio_rate = rt->rate;
	reg = ((125000000 / rt->rate) << 16) +
	((125000000 % rt->rate) << 16) / rt->rate;

	reg_write(dev, AUDIO_CONTROL2, reg);
	}

	if (dev->period_size != period_size) {
	u32 reg;

	dev->period_size = period_size;
	reg = reg_read(dev, AUDIO_CONTROL1);
	reg &= ~(AUDIO_DMA_SIZE_MASK << AUDIO_DMA_SIZE_SHIFT);
	reg \|= period_size << AUDIO_DMA_SIZE_SHIFT;

	reg_write(dev, AUDIO_CONTROL1, reg);
	}

	if (rt->periods < TW686X_AUDIO_PERIODS_MIN \|\|
	rt->periods > TW686X_AUDIO_PERIODS_MAX)
	return -EINVAL;

	spin_lock_irqsave(&ac->lock, flags);
	INIT_LIST_HEAD(&ac->buf_list);

	for (i = 0; i < rt->periods; i++) {
	ac->buf[i].dma = rt->dma_addr + period_size * i;
	ac->buf[i].virt = rt->dma_area + period_size * i;
	INIT_LIST_HEAD(&ac->buf[i].list);
	list_add_tail(&ac->buf[i].list, &ac->buf_list);
	}

	p_buf = list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
	list_move_tail(&p_buf->list, &ac->buf_list);

	b_buf = list_first_entry(&ac->buf_list, struct tw686x_audio_buf, list);
	list_move_tail(&b_buf->list, &ac->buf_list);

	ac->curr_bufs[0] = p_buf;
	ac->curr_bufs[1] = b_buf;
	ac->ptr = 0;

	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY) {
	reg_write(dev, ADMA_P_ADDR[ac->ch], p_buf->dma);
	reg_write(dev, ADMA_B_ADDR[ac->ch], b_buf->dma);
	}

	spin_unlock_irqrestore(&ac->lock, flags);

	return 0;

	err_audio_busy:
	spin_unlock_irqrestore(&dev->lock, flags);
	return -EBUSY;
	}

	static int tw686x_pcm_trigger(struct snd_pcm_substream *ss, int cmd)
	{
	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];
	unsigned long flags;
	int err = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	if (ac->curr_bufs[0] && ac->curr_bufs[1]) {
	spin_lock_irqsave(&dev->lock, flags);
	dev->audio_enabled = 1;
	tw686x_enable_channel(dev,
	AUDIO_CHANNEL_OFFSET + ac->ch);
	spin_unlock_irqrestore(&dev->lock, flags);

	mod_timer(&dev->dma_delay_timer,
	jiffies + msecs_to_jiffies(100));
	} else {
	err = -EIO;
	}
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	spin_lock_irqsave(&dev->lock, flags);
	dev->audio_enabled = 0;
	tw686x_disable_channel(dev, AUDIO_CHANNEL_OFFSET + ac->ch);
	spin_unlock_irqrestore(&dev->lock, flags);

	spin_lock_irqsave(&ac->lock, flags);
	ac->curr_bufs[0] = NULL;
	ac->curr_bufs[1] = NULL;
	spin_unlock_irqrestore(&ac->lock, flags);
	break;
	default:
	err = -EINVAL;
	}
	return err;
	}

	static snd_pcm_uframes_t tw686x_pcm_pointer(struct snd_pcm_substream *ss)
	{
	struct tw686x_dev *dev = snd_pcm_substream_chip(ss);
	struct tw686x_audio_channel *ac = &dev->audio_channels[ss->number];

	return bytes_to_frames(ss->runtime, ac->ptr);
	}

	static const struct snd_pcm_ops tw686x_pcm_ops = {
	.open = tw686x_pcm_open,
	.close = tw686x_pcm_close,
	.prepare = tw686x_pcm_prepare,
	.trigger = tw686x_pcm_trigger,
	.pointer = tw686x_pcm_pointer,
	};

	static int tw686x_snd_pcm_init(struct tw686x_dev *dev)
	{
	struct snd_card *card = dev->snd_card;
	struct snd_pcm *pcm;
	struct snd_pcm_substream *ss;
	unsigned int i;
	int err;

	err = snd_pcm_new(card, card->driver, 0, 0, max_channels(dev), &pcm);
	if (err < 0)
	return err;

	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &tw686x_pcm_ops);
	snd_pcm_chip(pcm) = dev;
	pcm->info_flags = 0;
	strscpy(pcm->name, "tw686x PCM", sizeof(pcm->name));

	for (i = 0, ss = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
	ss; ss = ss->next, i++)
	snprintf(ss->name, sizeof(ss->name), "vch%u audio", i);

	snd_pcm_set_managed_buffer_all(pcm,
	SNDRV_DMA_TYPE_DEV,
	&dev->pci_dev->dev,
	TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX,
	TW686X_AUDIO_PAGE_MAX * AUDIO_DMA_SIZE_MAX);
	return 0;
	}

	static void tw686x_audio_dma_free(struct tw686x_dev *dev,
	struct tw686x_audio_channel *ac)
	{
	int pb;

	for (pb = 0; pb < 2; pb++) {
	if (!ac->dma_descs[pb].virt)
	continue;
	pci_free_consistent(dev->pci_dev, ac->dma_descs[pb].size,
	ac->dma_descs[pb].virt,
	ac->dma_descs[pb].phys);
	ac->dma_descs[pb].virt = NULL;
	}
	}

	static int tw686x_audio_dma_alloc(struct tw686x_dev *dev,
	struct tw686x_audio_channel *ac)
	{
	int pb;

	/*
	* In the memcpy DMA mode we allocate a consistent buffer
	* and use it for the DMA capture. Otherwise, DMA
	* acts on the ALSA buffers as received in pcm_prepare.
	*/
	if (dev->dma_mode != TW686X_DMA_MODE_MEMCPY)
	return 0;

	for (pb = 0; pb < 2; pb++) {
	u32 reg = pb ? ADMA_B_ADDR[ac->ch] : ADMA_P_ADDR[ac->ch];
	void *virt;

	virt = pci_alloc_consistent(dev->pci_dev, AUDIO_DMA_SIZE_MAX,
	&ac->dma_descs[pb].phys);
	if (!virt) {
	dev_err(&dev->pci_dev->dev,
	"dma%d: unable to allocate audio DMA %s-buffer\n",
	ac->ch, pb ? "B" : "P");
	return -ENOMEM;
	}
	ac->dma_descs[pb].virt = virt;
	ac->dma_descs[pb].size = AUDIO_DMA_SIZE_MAX;
	reg_write(dev, reg, ac->dma_descs[pb].phys);
	}
	return 0;
	}

	void tw686x_audio_free(struct tw686x_dev *dev)
	{
	unsigned long flags;
	u32 dma_ch_mask;
	u32 dma_cmd;

	spin_lock_irqsave(&dev->lock, flags);
	dma_cmd = reg_read(dev, DMA_CMD);
	dma_ch_mask = reg_read(dev, DMA_CHANNEL_ENABLE);
	reg_write(dev, DMA_CMD, dma_cmd & ~0xff00);
	reg_write(dev, DMA_CHANNEL_ENABLE, dma_ch_mask & ~0xff00);
	spin_unlock_irqrestore(&dev->lock, flags);

	if (!dev->snd_card)
	return;
	snd_card_free(dev->snd_card);
	dev->snd_card = NULL;
	}

	int tw686x_audio_init(struct tw686x_dev *dev)
	{
	struct pci_dev *pci_dev = dev->pci_dev;
	struct snd_card *card;
	int err, ch;

	/* Enable external audio */
	reg_write(dev, AUDIO_CONTROL1, BIT(0));

	err = snd_card_new(&pci_dev->dev, SNDRV_DEFAULT_IDX1,
	SNDRV_DEFAULT_STR1,
	THIS_MODULE, 0, &card);
	if (err < 0)
	return err;

	dev->snd_card = card;
	strscpy(card->driver, "tw686x", sizeof(card->driver));
	strscpy(card->shortname, "tw686x", sizeof(card->shortname));
	strscpy(card->longname, pci_name(pci_dev), sizeof(card->longname));
	snd_card_set_dev(card, &pci_dev->dev);

	for (ch = 0; ch < max_channels(dev); ch++) {
	struct tw686x_audio_channel *ac;

	ac = &dev->audio_channels[ch];
	spin_lock_init(&ac->lock);
	ac->dev = dev;
	ac->ch = ch;

	err = tw686x_audio_dma_alloc(dev, ac);
	if (err < 0)
	goto err_cleanup;
	}

	err = tw686x_snd_pcm_init(dev);
	if (err < 0)
	goto err_cleanup;

	err = snd_card_register(card);
	if (!err)
	return 0;

	err_cleanup:
	for (ch = 0; ch < max_channels(dev); ch++) {
	if (!dev->audio_channels[ch].dev)
	continue;
	tw686x_audio_dma_free(dev, &dev->audio_channels[ch]);
	}
	snd_card_free(card);
	dev->snd_card = NULL;
	return err;
	}