soc-core.c

linux 内核源代码

/*
 * soc-core.c  --  ALSA SoC Audio Layer
 *
 * Copyright 2005 Wolfson Microelectronics PLC.
 * Copyright 2005 Openedhand Ltd.
 *
 * Author: Liam Girdwood
 *         [e-mail] or [e-mail]
 *         with code, comments and ideas from :-
 *         Richard Purdie <[e-mail]>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  Revision history
 *    12th Aug 2005   Initial version.
 *    25th Oct 2005   Working Codec, Interface and Platform registration.
 *
 *  TODO:
 *   o Add hw rules to enforce rates, etc.
 *   o More testing with other codecs/machines.
 *   o Add more codecs and platforms to ensure good API coverage.
 *   o Support TDM on PCM and I2S
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>
#include <sound/driver.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/soc-dapm.h>
#include <sound/initval.h>

/* debug */
#define SOC_DEBUG 0
#if SOC_DEBUG
#define dbg(format, arg...) printk(format, ## arg)
#else
#define dbg(format, arg...)
#endif

static DEFINE_MUTEX(pcm_mutex);
static DEFINE_MUTEX(io_mutex);
static DECLARE_WAIT_QUEUE_HEAD(soc_pm_waitq);

/*
 * This is a timeout to do a DAPM powerdown after a stream is closed().
 * It can be used to eliminate pops between different playback streams, e.g.
 * between two audio tracks.
 */
static int pmdown_time = 5000;
module_param(pmdown_time, int, 0);
MODULE_PARM_DESC(pmdown_time, "DAPM stream powerdown time (msecs)");

/*
 * This function forces any delayed work to be queued and run.
 */
static int run_delayed_work(struct delayed_work *dwork)
{
	int ret;

	/* cancel any work waiting to be queued. */
	ret = cancel_delayed_work(dwork);

	/* if there was any work waiting then we run it now and
	 * wait for it's completion */
	if (ret) {
		schedule_delayed_work(dwork, 0);
		flush_scheduled_work();
	}
	return ret;
}

#ifdef CONFIG_SND_SOC_AC97_BUS
/* unregister ac97 codec */
static int soc_ac97_dev_unregister(struct snd_soc_codec *codec)
{
	if (codec->ac97->dev.bus)
		device_unregister(&codec->ac97->dev);
	return 0;
}

/* stop no dev release warning */
static void soc_ac97_device_release(struct device *dev){}

/* register ac97 codec to bus */
static int soc_ac97_dev_register(struct snd_soc_codec *codec)
{
	int err;

	codec->ac97->dev.bus = &ac97_bus_type;
	codec->ac97->dev.parent = NULL;
	codec->ac97->dev.release = soc_ac97_device_release;

	snprintf(codec->ac97->dev.bus_id, BUS_ID_SIZE, "%d-%d:%s",
		 codec->card->number, 0, codec->name);
	err = device_register(&codec->ac97->dev);
	if (err < 0) {
		snd_printk(KERN_ERR "Can't register ac97 bus\n");
		codec->ac97->dev.bus = NULL;
		return err;
	}
	return 0;
}
#endif

static inline const char* get_dai_name(int type)
{
	switch(type) {
	case SND_SOC_DAI_AC97_BUS:
	case SND_SOC_DAI_AC97:
		return "AC97";
	case SND_SOC_DAI_I2S:
		return "I2S";
	case SND_SOC_DAI_PCM:
		return "PCM";
	}
	return NULL;
}

/*
 * Called by ALSA when a PCM substream is opened, the runtime->hw record is
 * then initialized and any private data can be allocated. This also calls
 * startup for the cpu DAI, platform, machine and codec DAI.
 */
static int soc_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_soc_dai_link *machine = rtd->dai;
	struct snd_soc_platform *platform = socdev->platform;
	struct snd_soc_cpu_dai *cpu_dai = machine->cpu_dai;
	struct snd_soc_codec_dai *codec_dai = machine->codec_dai;
	int ret = 0;

	mutex_lock(&pcm_mutex);

	/* startup the audio subsystem */
	if (cpu_dai->ops.startup) {
		ret = cpu_dai->ops.startup(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open interface %s\n",
				cpu_dai->name);
			goto out;
		}
	}

	if (platform->pcm_ops->open) {
		ret = platform->pcm_ops->open(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open platform %s\n", platform->name);
			goto platform_err;
		}
	}

	if (codec_dai->ops.startup) {
		ret = codec_dai->ops.startup(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't open codec %s\n",
				codec_dai->name);
			goto codec_dai_err;
		}
	}

	if (machine->ops && machine->ops->startup) {
		ret = machine->ops->startup(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: %s startup failed\n", machine->name);
			goto machine_err;
		}
	}

	/* Check that the codec and cpu DAI's are compatible */
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		runtime->hw.rate_min =
			max(codec_dai->playback.rate_min, cpu_dai->playback.rate_min);
		runtime->hw.rate_max =
			min(codec_dai->playback.rate_max, cpu_dai->playback.rate_max);
		runtime->hw.channels_min =
			max(codec_dai->playback.channels_min,
				cpu_dai->playback.channels_min);
		runtime->hw.channels_max =
			min(codec_dai->playback.channels_max,
				cpu_dai->playback.channels_max);
		runtime->hw.formats =
			codec_dai->playback.formats & cpu_dai->playback.formats;
		runtime->hw.rates =
			codec_dai->playback.rates & cpu_dai->playback.rates;
	} else {
		runtime->hw.rate_min =
			max(codec_dai->capture.rate_min, cpu_dai->capture.rate_min);
		runtime->hw.rate_max =
			min(codec_dai->capture.rate_max, cpu_dai->capture.rate_max);
		runtime->hw.channels_min =
			max(codec_dai->capture.channels_min,
				cpu_dai->capture.channels_min);
		runtime->hw.channels_max =
			min(codec_dai->capture.channels_max,
				cpu_dai->capture.channels_max);
		runtime->hw.formats =
			codec_dai->capture.formats & cpu_dai->capture.formats;
		runtime->hw.rates =
			codec_dai->capture.rates & cpu_dai->capture.rates;
	}

	snd_pcm_limit_hw_rates(runtime);
	if (!runtime->hw.rates) {
		printk(KERN_ERR "asoc: %s <-> %s No matching rates\n",
			codec_dai->name, cpu_dai->name);
		goto machine_err;
	}
	if (!runtime->hw.formats) {
		printk(KERN_ERR "asoc: %s <-> %s No matching formats\n",
			codec_dai->name, cpu_dai->name);
		goto machine_err;
	}
	if (!runtime->hw.channels_min || !runtime->hw.channels_max) {
		printk(KERN_ERR "asoc: %s <-> %s No matching channels\n",
			codec_dai->name, cpu_dai->name);
		goto machine_err;
	}

	dbg("asoc: %s <-> %s info:\n",codec_dai->name, cpu_dai->name);
	dbg("asoc: rate mask 0x%x\n", runtime->hw.rates);
	dbg("asoc: min ch %d max ch %d\n", runtime->hw.channels_min,
		runtime->hw.channels_max);
	dbg("asoc: min rate %d max rate %d\n", runtime->hw.rate_min,
		runtime->hw.rate_max);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		cpu_dai->playback.active = codec_dai->playback.active = 1;
	else
		cpu_dai->capture.active = codec_dai->capture.active = 1;
	cpu_dai->active = codec_dai->active = 1;
	cpu_dai->runtime = runtime;
	socdev->codec->active++;
	mutex_unlock(&pcm_mutex);
	return 0;

machine_err:
	if (machine->ops && machine->ops->shutdown)
		machine->ops->shutdown(substream);

codec_dai_err:
	if (platform->pcm_ops->close)
		platform->pcm_ops->close(substream);

platform_err:
	if (cpu_dai->ops.shutdown)
		cpu_dai->ops.shutdown(substream);
out:
	mutex_unlock(&pcm_mutex);
	return ret;
}

/*
 * Power down the audio subsystem pmdown_time msecs after close is called.
 * This is to ensure there are no pops or clicks in between any music tracks
 * due to DAPM power cycling.
 */
static void close_delayed_work(struct work_struct *work)
{
	struct snd_soc_device *socdev =
		container_of(work, struct snd_soc_device, delayed_work.work);
	struct snd_soc_codec *codec = socdev->codec;
	struct snd_soc_codec_dai *codec_dai;
	int i;

	mutex_lock(&pcm_mutex);
	for(i = 0; i < codec->num_dai; i++) {
		codec_dai = &codec->dai[i];

		dbg("pop wq checking: %s status: %s waiting: %s\n",
			codec_dai->playback.stream_name,
			codec_dai->playback.active ? "active" : "inactive",
			codec_dai->pop_wait ? "yes" : "no");

		/* are we waiting on this codec DAI stream */
		if (codec_dai->pop_wait == 1) {

			codec_dai->pop_wait = 0;
			snd_soc_dapm_stream_event(codec, codec_dai->playback.stream_name,
				SND_SOC_DAPM_STREAM_STOP);

			/* power down the codec power domain if no longer active */
			if (codec->active == 0) {
				dbg("pop wq D3 %s %s\n", codec->name,
					codec_dai->playback.stream_name);
		 		if (codec->dapm_event)
					codec->dapm_event(codec, SNDRV_CTL_POWER_D3hot);
			}
		}
	}
	mutex_unlock(&pcm_mutex);
}

/*
 * Called by ALSA when a PCM substream is closed. Private data can be
 * freed here. The cpu DAI, codec DAI, machine and platform are also
 * shutdown.
 */
static int soc_codec_close(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_dai_link *machine = rtd->dai;
	struct snd_soc_platform *platform = socdev->platform;
	struct snd_soc_cpu_dai *cpu_dai = machine->cpu_dai;
	struct snd_soc_codec_dai *codec_dai = machine->codec_dai;
	struct snd_soc_codec *codec = socdev->codec;

	mutex_lock(&pcm_mutex);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		cpu_dai->playback.active = codec_dai->playback.active = 0;
	else
		cpu_dai->capture.active = codec_dai->capture.active = 0;

	if (codec_dai->playback.active == 0 &&
		codec_dai->capture.active == 0) {
		cpu_dai->active = codec_dai->active = 0;
	}
	codec->active--;

	if (cpu_dai->ops.shutdown)
		cpu_dai->ops.shutdown(substream);

	if (codec_dai->ops.shutdown)
		codec_dai->ops.shutdown(substream);

	if (machine->ops && machine->ops->shutdown)
		machine->ops->shutdown(substream);

	if (platform->pcm_ops->close)
		platform->pcm_ops->close(substream);
	cpu_dai->runtime = NULL;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		/* start delayed pop wq here for playback streams */
		codec_dai->pop_wait = 1;
		schedule_delayed_work(&socdev->delayed_work,
			msecs_to_jiffies(pmdown_time));
	} else {
		/* capture streams can be powered down now */
		snd_soc_dapm_stream_event(codec,
			codec_dai->capture.stream_name, SND_SOC_DAPM_STREAM_STOP);

		if (codec->active == 0 && codec_dai->pop_wait == 0){
			if (codec->dapm_event)
				codec->dapm_event(codec, SNDRV_CTL_POWER_D3hot);
		}
	}

	mutex_unlock(&pcm_mutex);
	return 0;
}

/*
 * Called by ALSA when the PCM substream is prepared, can set format, sample
 * rate, etc.  This function is non atomic and can be called multiple times,
 * it can refer to the runtime info.
 */
static int soc_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_dai_link *machine = rtd->dai;
	struct snd_soc_platform *platform = socdev->platform;
	struct snd_soc_cpu_dai *cpu_dai = machine->cpu_dai;
	struct snd_soc_codec_dai *codec_dai = machine->codec_dai;
	struct snd_soc_codec *codec = socdev->codec;
	int ret = 0;

	mutex_lock(&pcm_mutex);

	if (machine->ops && machine->ops->prepare) {
		ret = machine->ops->prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: machine prepare error\n");
			goto out;
		}
	}

	if (platform->pcm_ops->prepare) {
		ret = platform->pcm_ops->prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: platform prepare error\n");
			goto out;
		}
	}

	if (codec_dai->ops.prepare) {
		ret = codec_dai->ops.prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: codec DAI prepare error\n");
			goto out;
		}
	}

	if (cpu_dai->ops.prepare) {
		ret = cpu_dai->ops.prepare(substream);
		if (ret < 0) {
			printk(KERN_ERR "asoc: cpu DAI prepare error\n");
			goto out;
		}
	}

	/* we only want to start a DAPM playback stream if we are not waiting
	 * on an existing one stopping */
	if (codec_dai->pop_wait) {
		/* we are waiting for the delayed work to start */
		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
				snd_soc_dapm_stream_event(socdev->codec,
					codec_dai->capture.stream_name,
					SND_SOC_DAPM_STREAM_START);
		else {
			codec_dai->pop_wait = 0;
			cancel_delayed_work(&socdev->delayed_work);
			if (codec_dai->dai_ops.digital_mute)
				codec_dai->dai_ops.digital_mute(codec_dai, 0);
		}
	} else {
		/* no delayed work - do we need to power up codec */
		if (codec->dapm_state != SNDRV_CTL_POWER_D0) {

			if (codec->dapm_event)
				codec->dapm_event(codec, SNDRV_CTL_POWER_D1);

			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
				snd_soc_dapm_stream_event(codec,
					codec_dai->playback.stream_name,
					SND_SOC_DAPM_STREAM_START);
			else
				snd_soc_dapm_stream_event(codec,
					codec_dai->capture.stream_name,
					SND_SOC_DAPM_STREAM_START);

			if (codec->dapm_event)
				codec->dapm_event(codec, SNDRV_CTL_POWER_D0);
			if (codec_dai->dai_ops.digital_mute)
				codec_dai->dai_ops.digital_mute(codec_dai, 0);

		} else {
			/* codec already powered - power on widgets */
			if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
				snd_soc_dapm_stream_event(codec,
					codec_dai->playback.stream_name,
					SND_SOC_DAPM_STREAM_START);
			else
				snd_soc_dapm_stream_event(codec,
					codec_dai->capture.stream_name,
					SND_SOC_DAPM_STREAM_START);
			if (codec_dai->dai_ops.digital_mute)
				codec_dai->dai_ops.digital_mute(codec_dai, 0);
		}
	}

out:
	mutex_unlock(&pcm_mutex);
	return ret;
}

/*
 * Called by ALSA when the hardware params are set by application. This
 * function can also be called multiple times and can allocate buffers
 * (using snd_pcm_lib_* ). It's non-atomic.
 */
static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_device *socdev = rtd->socdev;
	struct snd_soc_dai_link *machine = rtd->dai;
	struct snd_soc_platform *platform = socdev->platform;
	struct snd_soc_cpu_dai *cpu_dai = machine->cpu_dai;
	struct snd_soc_codec_dai *codec_dai = machine->codec_dai;
	int ret = 0;

	mutex_lock(&pcm_mutex);

	if (machine->ops && machine->ops->hw_params) {
		ret = machine->ops->hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: machine hw_params failed\n");
			goto out;
		}
	}

	if (codec_dai->ops.hw_params) {
		ret = codec_dai->ops.hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't set codec %s hw params\n",
				codec_dai->name);
			goto codec_err;
		}
	}

	if (cpu_dai->ops.hw_params) {
		ret = cpu_dai->ops.hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't set interface %s hw params\n",
				cpu_dai->name);
			goto interface_err;
		}
	}

	if (platform->pcm_ops->hw_params) {
		ret = platform->pcm_ops->hw_params(substream, params);
		if (ret < 0) {
			printk(KERN_ERR "asoc: can't set platform %s hw params\n",
				platform->name);
			goto platform_err;
		}
	}

out:
	mutex_unlock(&pcm_mutex);