For udev, we need a way to rename soundcard names. The soundcard numbers (indexes) are hardwired but we have a text identification which can be changed at run-time. The ALSA user space tools already allow using of this text identification.
Signed-off-by: Jaroslav Kysela perex@perex.cz --- sound/core/init.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 65 insertions(+), 1 deletions(-)
diff --git a/sound/core/init.c b/sound/core/init.c index b47ff8b..1426abd 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -533,6 +533,64 @@ static void choose_default_id(struct snd_card *card) } }
+#ifndef CONFIG_SYSFS_DEPRECATED +static ssize_t +card_id_show_attr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%s\n", card ? card->id : "(null)"); +} + +static ssize_t +card_id_store_attr(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct snd_card *card = dev_get_drvdata(dev); + char buf1[sizeof(card->id)]; + size_t copy = count > sizeof(card->id) - 1 ? + sizeof(card->id) - 1 : count; + size_t idx; + int c; + + for (idx = 0; idx < copy; idx++) { + c = buf[idx]; + if (!isalnum(c) && c != '_' && c != '-') + return -EINVAL; + } + memcpy(buf1, buf, copy); + buf1[copy] = '\0'; + mutex_lock(&snd_card_mutex); + if (!snd_info_check_reserved_words(buf1)) { + __exist: + mutex_unlock(&snd_card_mutex); + return -EEXIST; + } + for (idx = 0; idx < snd_ecards_limit; idx++) { + if (snd_cards[idx] && !strcmp(snd_cards[idx]->id, buf1)) + goto __exist; + } + strcpy(card->id, buf1); + mutex_unlock(&snd_card_mutex); + + return count; +} + +static struct device_attribute card_id_attrs = + __ATTR(id, S_IRUGO | S_IWUSR, card_id_show_attr, card_id_store_attr); + +static ssize_t +card_number_show_attr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct snd_card *card = dev_get_drvdata(dev); + return snprintf(buf, PAGE_SIZE, "%i\n", card ? card->number : -1); +} + +static struct device_attribute card_number_attrs = + __ATTR(number, S_IRUGO, card_number_show_attr, NULL); +#endif /* CONFIG_SYSFS_DEPRECATED */ + /** * snd_card_register - register the soundcard * @card: soundcard structure @@ -553,7 +611,7 @@ int snd_card_register(struct snd_card *card) #ifndef CONFIG_SYSFS_DEPRECATED if (!card->card_dev) { card->card_dev = device_create(sound_class, card->dev, - MKDEV(0, 0), NULL, + MKDEV(0, 0), card, "card%i", card->number); if (IS_ERR(card->card_dev)) card->card_dev = NULL; @@ -576,6 +634,12 @@ int snd_card_register(struct snd_card *card) if (snd_mixer_oss_notify_callback) snd_mixer_oss_notify_callback(card, SND_MIXER_OSS_NOTIFY_REGISTER); #endif +#ifndef CONFIG_SYSFS_DEPRECATED + if (card->card_dev) { + device_create_file(card->card_dev, &card_id_attrs); + device_create_file(card->card_dev, &card_number_attrs); + } +#endif return 0; }