sound/soc/soc-core.c
static int __init snd_soc_init(void)
{
#ifdef CONFIG_DEBUG_FS
snd_soc_debugfs_root = debugfs_create_dir("asoc", NULL);
if (IS_ERR(snd_soc_debugfs_root) || !snd_soc_debugfs_root) {
pr_warn("ASoC: Failed to create debugfs directory
");
snd_soc_debugfs_root = NULL;
}
if (!debugfs_create_file("codecs", 0444, snd_soc_debugfs_root, NULL,
&codec_list_fops))
pr_warn("ASoC: Failed to create CODEC list debugfs file
");
if (!debugfs_create_file("dais", 0444, snd_soc_debugfs_root, NULL,
&dai_list_fops))
pr_warn("ASoC: Failed to create DAI list debugfs file
");
if (!debugfs_create_file("platforms", 0444, snd_soc_debugfs_root, NULL,
&platform_list_fops))
pr_warn("ASoC: Failed to create platform list debugfs file
");
#endif
snd_soc_util_init();
return platform_driver_register(&soc_driver);
}
module_init(snd_soc_init);
const struct dev_pm_ops snd_soc_pm_ops = {
.suspend = snd_soc_suspend,
.resume = snd_soc_resume,
.freeze = snd_soc_suspend,
.thaw = snd_soc_resume,
.poweroff = snd_soc_poweroff,
.restore = snd_soc_resume,
};
EXPORT_SYMBOL_GPL(snd_soc_pm_ops);
/* ASoC platform driver */
static struct platform_driver soc_driver = {
.driver = {
.name = "soc-audio", // 声卡设备
.owner = THIS_MODULE,
.pm = &snd_soc_pm_ops,
},
.probe = soc_probe,
.remove = soc_remove,
};
static int soc_probe(struct platform_device *pdev)
{
// 获取声卡
struct snd_soc_card *card = platform_get_drvdata(pdev);
/*
* no card, so machine driver should be registering card
* we should not be here in that case so ret error
*/
if (!card)
return -EINVAL;
dev_warn(&pdev->dev,
"ASoC: machine %s should use snd_soc_register_card()
",
card->name);
/* Bodge while we unpick instantiation */
card->dev = &pdev->dev;
// 注册声卡
return snd_soc_register_card(card);
}
int snd_soc_register_card(struct snd_soc_card *card)
{
int i, j, ret;
if (!card->name || !card->dev)
return -EINVAL;
// 遍历dai_link的成员
for (i = 0; i < card->num_links; i++) {
struct snd_soc_dai_link *link = &card->dai_link[i];
// 初始化codec
ret = snd_soc_init_multicodec(card, link);
if (ret) {
dev_err(card->dev, "ASoC: failed to init multicodec
");
return ret;
}
for (j = 0; j < link->num_codecs; j++) {
/*
* Codec must be specified by 1 of name or OF node,
* not both or neither.
*/
if (!!link->codecs[j].name ==
!!link->codecs[j].of_node) {
dev_err(card->dev, "ASoC: Neither/both codec name/of_node are set for %s
",
link->name);
return -EINVAL;
}
/* Codec DAI name must be specified */
if (!link->codecs[j].dai_name) {
dev_err(card->dev, "ASoC: codec_dai_name not set for %s
",
link->name);
return -EINVAL;
}
}
/*
* Platform may be specified by either name or OF node, but
* can be left unspecified, and a dummy platform will be used.
*/
if (link->platform_name && link->platform_of_node) {
dev_err(card->dev,
"ASoC: Both platform name/of_node are set for %s
",
link->name);
return -EINVAL;
}
/*
* CPU device may be specified by either name or OF node, but
* can be left unspecified, and will be matched based on DAI
* name alone..
*/
if (link->cpu_name && link->cpu_of_node) {
dev_err(card->dev,
"ASoC: Neither/both cpu name/of_node are set for %s
",
link->name);
return -EINVAL;
}
/*
* At least one of CPU DAI name or CPU device name/node must be
* specified
*/
if (!link->cpu_dai_name &&
!(link->cpu_name || link->cpu_of_node)) {
dev_err(card->dev,
"ASoC: Neither cpu_dai_name nor cpu_name/of_node are set for %s
",
link->name);
return -EINVAL;
}
}
// 设置声卡驱动信息
dev_set_drvdata(card->dev, card);
// 声卡初始化列表, 初始几个链表
snd_soc_initialize_card_lists(card);
soc_init_card_debugfs(card);
// 分配空间
card->rtd = devm_kzalloc(card->dev,
sizeof(struct snd_soc_pcm_runtime) *
(card->num_links + card->num_aux_devs),
GFP_KERNEL);
if (card->rtd == NULL)
return -ENOMEM;
card->num_rtd = 0;
card->rtd_aux = &card->rtd[card->num_links];
for (i = 0; i < card->num_links; i++) {
card->rtd[i].card = card;
card->rtd[i].dai_link = &card->dai_link[i];
card->rtd[i].codec_dais = devm_kzalloc(card->dev,
sizeof(struct snd_soc_dai *) *
(card->rtd[i].dai_link->num_codecs),
GFP_KERNEL);
if (card->rtd[i].codec_dais == NULL)
return -ENOMEM;
}
for (i = 0; i < card->num_aux_devs; i++)
card->rtd_aux[i].card = card;
INIT_LIST_HEAD(&card->dapm_dirty);
card->instantiated = 0;
mutex_init(&card->mutex);
mutex_init(&card->dapm_mutex);
mutex_init(&card->dapm_power_mutex);
// 初始化声卡
ret = snd_soc_instantiate_card(card);
if (ret != 0)
soc_cleanup_card_debugfs(card);
/* deactivate pins to sleep state */
for (i = 0; i < card->num_rtd; i++) {
struct snd_soc_pcm_runtime *rtd = &card->rtd[i];
struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
int j;
for (j = 0; j < rtd->num_codecs; j++) {
struct snd_soc_dai *codec_dai = rtd->codec_dais[j];
if (!codec_dai->active)
pinctrl_pm_select_sleep_state(codec_dai->dev);
}
if (!cpu_dai->active)
pinctrl_pm_select_sleep_state(cpu_dai->dev);
}
return ret;
}
EXPORT_SYMBOL_GPL(snd_soc_register_card);
static int snd_soc_instantiate_card(struct snd_soc_card *card)
{
struct snd_soc_codec *codec;
struct snd_soc_dai_link *dai_link;
int ret, i, order, dai_fmt;
mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_INIT);
/* bind DAIs */
// 绑定DAI
for (i = 0; i < card->num_links; i++) {
ret = soc_bind_dai_link(card, i);
if (ret != 0)
goto base_error;
}
/* bind aux_devs too */
// 绑定AUX
for (i = 0; i < card->num_aux_devs; i++) {
ret = soc_bind_aux_dev(card, i);
if (ret != 0)
goto base_error;
}
/* initialize the register cache for each available codec */
list_for_each_entry(codec, &codec_list, list) {
if (codec->cache_init)
continue;
// 初始化codec缓存
ret = snd_soc_init_codec_cache(codec);
if (ret < 0)
goto base_error;
}
/* card bind complete so register a sound card */
// 注册声卡
ret = snd_card_new(card->dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
card->owner, 0, &card->snd_card);
if (ret < 0) {
dev_err(card->dev,
"ASoC: can't create sound card for card %s: %d
",
card->name, ret);
goto base_error;
}
card->dapm.bias_level = SND_SOC_BIAS_OFF;
card->dapm.dev = card->dev;
card->dapm.card = card;
list_add(&card->dapm.list, &card->dapm_list);
#ifdef CONFIG_DEBUG_FS
snd_soc_dapm_debugfs_init(&card->dapm, card->debugfs_card_root);
#endif
#ifdef CONFIG_PM_SLEEP
/* deferred resume work */
INIT_WORK(&card->deferred_resume_work, soc_resume_deferred);
#endif
if (card->dapm_widgets)
snd_soc_dapm_new_controls(&card->dapm, card->dapm_widgets,
card->num_dapm_widgets);
/* initialise the sound card only once */
if (card->probe) {
ret = card->probe(card);
if (ret < 0)
goto card_probe_error;
}
/* probe all components used by DAI links on this card */
for (order = SND_SOC_COMP_ORDER_FIRST; order <= SND_SOC_COMP_ORDER_LAST;
order++) {
for (i = 0; i < card->num_links; i++) {
ret = soc_probe_link_components(card, i, order);
if (ret < 0) {
dev_err(card->dev,
"ASoC: failed to instantiate card %d
",
ret);
goto probe_dai_err;
}
}
}
/* probe all DAI links on this card */
for (order = SND_SOC_COMP_ORDER_FIRST; order <= SND_SOC_COMP_ORDER_LAST;
order++) {
for (i = 0; i < card->num_links; i++) {
ret = soc_probe_link_dais(card, i, order);
if (ret < 0) {
dev_err(card->dev,
"ASoC: failed to instantiate card %d
",
ret);
goto probe_dai_err;
}
}
}
for (i = 0; i < card->num_aux_devs; i++) {
ret = soc_probe_aux_dev(card, i);
if (ret < 0) {
dev_err(card->dev,
"ASoC: failed to add auxiliary devices %d
",
ret);
goto probe_aux_dev_err;
}
}
snd_soc_dapm_link_dai_widgets(card);
snd_soc_dapm_connect_dai_link_widgets(card);
if (card->controls)
snd_soc_add_card_controls(card, card->controls, card->num_controls);
if (card->dapm_routes)
snd_soc_dapm_add_routes(&card->dapm, card->dapm_routes,
card->num_dapm_routes);
for (i = 0; i < card->num_links; i++) {
struct snd_soc_pcm_runtime *rtd = &card->rtd[i];
dai_link = &card->dai_link[i];
dai_fmt = dai_link->dai_fmt;
if (dai_fmt) {
struct snd_soc_dai **codec_dais = rtd->codec_dais;
int j;
for (j = 0; j < rtd->num_codecs; j++) {
struct snd_soc_dai *codec_dai = codec_dais[j];
ret = snd_soc_dai_set_fmt(codec_dai, dai_fmt);
if (ret != 0 && ret != -ENOTSUPP)
dev_warn(codec_dai->dev,
"ASoC: Failed to set DAI format: %d
",
ret);
}
}
/* If this is a regular CPU link there will be a platform */
if (dai_fmt &&
(dai_link->platform_name || dai_link->platform_of_node)) {
ret = snd_soc_dai_set_fmt(card->rtd[i].cpu_dai,
dai_fmt);
if (ret != 0 && ret != -ENOTSUPP)
dev_warn(card->rtd[i].cpu_dai->dev,
"ASoC: Failed to set DAI format: %d
",
ret);
} else if (dai_fmt) {
/* Flip the polarity for the "CPU" end */
dai_fmt &= ~SND_SOC_DAIFMT_MASTER_MASK;
switch (dai_link->dai_fmt &
SND_SOC_DAIFMT_MASTER_MASK) {
case SND_SOC_DAIFMT_CBM_CFM:
dai_fmt |= SND_SOC_DAIFMT_CBS_CFS;
break;
case SND_SOC_DAIFMT_CBM_CFS:
dai_fmt |= SND_SOC_DAIFMT_CBS_CFM;
break;
case SND_SOC_DAIFMT_CBS_CFM:
dai_fmt |= SND_SOC_DAIFMT_CBM_CFS;
break;
case SND_SOC_DAIFMT_CBS_CFS:
dai_fmt |= SND_SOC_DAIFMT_CBM_CFM;
break;
}
ret = snd_soc_dai_set_fmt(card->rtd[i].cpu_dai,
dai_fmt);
if (ret != 0 && ret != -ENOTSUPP)
dev_warn(card->rtd[i].cpu_dai->dev,
"ASoC: Failed to set DAI format: %d
",
ret);
}
}
snprintf(card->snd_card->shortname, sizeof(card->snd_card->shortname),
"%s", card->name);
snprintf(card->snd_card->longname, sizeof(card->snd_card->longname),
"%s", card->long_name ? card->long_name : card->name);
snprintf(card->snd_card->driver, sizeof(card->snd_card->driver),
"%s", card->driver_name ? card->driver_name : card->name);
for (i = 0; i < ARRAY_SIZE(card->snd_card->driver); i++) {
switch (card->snd_card->driver[i]) {
case '_':
case '-':
case ' ':
break;
default:
if (!isalnum(card->snd_card->driver[i]))
card->snd_card->driver[i] = '_';
break;
}
}
if (card->late_probe) {
ret = card->late_probe(card);
if (ret < 0) {
dev_err(card->dev, "ASoC: %s late_probe() failed: %d
",
card->name, ret);
goto probe_aux_dev_err;
}
}
if (card->fully_routed)
snd_soc_dapm_auto_nc_pins(card);
snd_soc_dapm_new_widgets(card);
ret = snd_card_register(card->snd_card);
if (ret < 0) {
dev_err(card->dev, "ASoC: failed to register soundcard %d
",
ret);
goto probe_aux_dev_err;
}
#ifdef CONFIG_SND_SOC_AC97_BUS
/* register any AC97 codecs */
for (i = 0; i < card->num_rtd; i++) {
ret = soc_register_ac97_dai_link(&card->rtd[i]);
if (ret < 0) {
dev_err(card->dev,
"ASoC: failed to register AC97: %d
", ret);
while (--i >= 0)
soc_unregister_ac97_dai_link(&card->rtd[i]);
goto probe_aux_dev_err;
}
}
#endif
card->instantiated = 1;
snd_soc_dapm_sync(&card->dapm);
mutex_unlock(&card->mutex);
return 0;
probe_aux_dev_err:
for (i = 0; i < card->num_aux_devs; i++)
soc_remove_aux_dev(card, i);
probe_dai_err:
soc_remove_dai_links(card);
card_probe_error:
if (card->remove)
card->remove(card);
snd_card_free(card->snd_card);
base_error:
mutex_unlock(&card->mutex);
return ret;
}
static int soc_bind_dai_link(struct snd_soc_card *card, int num)
{
struct snd_soc_dai_link *dai_link = &card->dai_link[num];
struct snd_soc_pcm_runtime *rtd = &card->rtd[num];
struct snd_soc_dai_link_component *codecs = dai_link->codecs;
struct snd_soc_dai_link_component cpu_dai_component;
struct snd_soc_dai **codec_dais = rtd->codec_dais;
struct snd_soc_platform *platform;
const char *platform_name;
int i;
dev_dbg(card->dev, "ASoC: binding %s at idx %d
", dai_link->name, num);
cpu_dai_component.name = dai_link->cpu_name;
cpu_dai_component.of_node = dai_link->cpu_of_node;
cpu_dai_component.dai_name = dai_link->cpu_dai_name;
// 匹配和machine匹配的cpu dai driver
rtd->cpu_dai = snd_soc_find_dai(&cpu_dai_component);
if (!rtd->cpu_dai) {
dev_err(card->dev, "ASoC: CPU DAI %s not registered
",
dai_link->cpu_dai_name);
return -EPROBE_DEFER;
}
rtd->num_codecs = dai_link->num_codecs;
/* Find CODEC from registered CODECs */
for (i = 0; i < rtd->num_codecs; i++) {
codec_dais[i] = snd_soc_find_dai(&codecs[i]);
if (!codec_dais[i]) {
dev_err(card->dev, "ASoC: CODEC DAI %s not registered
",
codecs[i].dai_name);
return -EPROBE_DEFER;
}
}
/* Single codec links expect codec and codec_dai in runtime data */
rtd->codec_dai = codec_dais[0];
rtd->codec = rtd->codec_dai->codec;
/* if there's no platform we match on the empty platform */
platform_name = dai_link->platform_name;
if (!platform_name && !dai_link->platform_of_node)
platform_name = "snd-soc-dummy";
/* find one from the set of registered platforms */
list_for_each_entry(platform, &platform_list, list) {
if (dai_link->platform_of_node) {
// 根据设备数节点进行匹配
if (platform->dev->of_node !=
dai_link->platform_of_node)
continue;
} else {
// 根据name进行匹配
if (strcmp(platform->component.name, platform_name))
continue;
}
rtd->platform = platform;
}
if (!rtd->platform) {
dev_err(card->dev, "ASoC: platform %s not registered
",
dai_link->platform_name);
return -EPROBE_DEFER;
}
card->num_rtd++;
return 0;
}