[ALSA] Add pcm_class attribute to PCM sysfs entry
This patch adds a new attribute, pcm_class, to each PCM sysfs entry.
It's useful to detect what kind of PCM stream is, for example, HAL
can check whether it's a modem or not.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>
diff --git a/include/sound/core.h b/include/sound/core.h
index 1359c53..b056ea9 100644
--- a/include/sound/core.h
+++ b/include/sound/core.h
@@ -26,6 +26,7 @@
#include <linux/mutex.h> /* struct mutex */
#include <linux/rwsem.h> /* struct rw_semaphore */
#include <linux/pm.h> /* pm_message_t */
+#include <linux/device.h>
/* forward declarations */
#ifdef CONFIG_PCI
@@ -186,6 +187,7 @@
int device; /* device number */
const struct file_operations *f_ops; /* file operations */
void *private_data; /* private data for f_ops->open */
+ struct class_device *class_dev; /* class device for sysfs */
};
/* sound.c */
@@ -200,6 +202,8 @@
const char *name);
int snd_unregister_device(int type, struct snd_card *card, int dev);
void *snd_lookup_minor_data(unsigned int minor, int type);
+int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
+ const struct class_device_attribute *attr);
#ifdef CONFIG_SND_OSSEMUL
int snd_register_oss_device(int type, struct snd_card *card, int dev,
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index ed3b094..bf8f412 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -907,6 +907,28 @@
substream->pstr->substream_opened--;
}
+static ssize_t show_pcm_class(struct class_device *class_device, char *buf)
+{
+ struct snd_pcm *pcm;
+ const char *str;
+ static const char *strs[SNDRV_PCM_CLASS_LAST + 1] = {
+ [SNDRV_PCM_CLASS_GENERIC] = "generic",
+ [SNDRV_PCM_CLASS_MULTI] = "multi",
+ [SNDRV_PCM_CLASS_MODEM] = "modem",
+ [SNDRV_PCM_CLASS_DIGITIZER] = "digitizer",
+ };
+
+ if (! (pcm = class_get_devdata(class_device)) ||
+ pcm->dev_class > SNDRV_PCM_CLASS_LAST)
+ str = "none";
+ else
+ str = strs[pcm->dev_class];
+ return snprintf(buf, PAGE_SIZE, "%s\n", str);
+}
+
+static struct class_device_attribute pcm_attrs =
+ __ATTR(pcm_class, S_IRUGO, show_pcm_class, NULL);
+
static int snd_pcm_dev_register(struct snd_device *device)
{
int cidx, err;
@@ -945,6 +967,8 @@
mutex_unlock(®ister_mutex);
return err;
}
+ snd_add_device_sysfs_file(devtype, pcm->card, pcm->device,
+ &pcm_attrs);
for (substream = pcm->streams[cidx].substream; substream; substream = substream->next)
snd_pcm_timer_init(substream);
}
diff --git a/sound/core/sound.c b/sound/core/sound.c
index b4430db..efa476c 100644
--- a/sound/core/sound.c
+++ b/sound/core/sound.c
@@ -268,7 +268,11 @@
snd_minors[minor] = preg;
if (card)
device = card->dev;
- class_device_create(sound_class, NULL, MKDEV(major, minor), device, "%s", name);
+ preg->class_dev = class_device_create(sound_class, NULL,
+ MKDEV(major, minor),
+ device, "%s", name);
+ if (preg->class_dev)
+ class_set_devdata(preg->class_dev, private_data);
mutex_unlock(&sound_mutex);
return 0;
@@ -276,6 +280,24 @@
EXPORT_SYMBOL(snd_register_device);
+/* find the matching minor record
+ * return the index of snd_minor, or -1 if not found
+ */
+static int find_snd_minor(int type, struct snd_card *card, int dev)
+{
+ int cardnum, minor;
+ struct snd_minor *mptr;
+
+ cardnum = card ? card->number : -1;
+ for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
+ if ((mptr = snd_minors[minor]) != NULL &&
+ mptr->type == type &&
+ mptr->card == cardnum &&
+ mptr->device == dev)
+ return minor;
+ return -1;
+}
+
/**
* snd_unregister_device - unregister the device on the given card
* @type: the device type, SNDRV_DEVICE_TYPE_XXX
@@ -289,32 +311,42 @@
*/
int snd_unregister_device(int type, struct snd_card *card, int dev)
{
- int cardnum, minor;
- struct snd_minor *mptr;
+ int minor;
- cardnum = card ? card->number : -1;
mutex_lock(&sound_mutex);
- for (minor = 0; minor < ARRAY_SIZE(snd_minors); ++minor)
- if ((mptr = snd_minors[minor]) != NULL &&
- mptr->type == type &&
- mptr->card == cardnum &&
- mptr->device == dev)
- break;
- if (minor == ARRAY_SIZE(snd_minors)) {
+ minor = find_snd_minor(type, card, dev);
+ if (minor < 0) {
mutex_unlock(&sound_mutex);
return -EINVAL;
}
class_device_destroy(sound_class, MKDEV(major, minor));
+ kfree(snd_minors[minor]);
snd_minors[minor] = NULL;
mutex_unlock(&sound_mutex);
- kfree(mptr);
return 0;
}
EXPORT_SYMBOL(snd_unregister_device);
+int snd_add_device_sysfs_file(int type, struct snd_card *card, int dev,
+ const struct class_device_attribute *attr)
+{
+ int minor, ret = -EINVAL;
+ struct class_device *cdev;
+
+ mutex_lock(&sound_mutex);
+ minor = find_snd_minor(type, card, dev);
+ if (minor >= 0 && (cdev = snd_minors[minor]->class_dev) != NULL)
+ ret = class_device_create_file(cdev, attr);
+ mutex_unlock(&sound_mutex);
+ return ret;
+
+}
+
+EXPORT_SYMBOL(snd_add_device_sysfs_file);
+
#ifdef CONFIG_PROC_FS
/*
* INFO PART