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-rw-r--r--sound/core/device.c244
1 files changed, 244 insertions, 0 deletions
diff --git a/sound/core/device.c b/sound/core/device.c
new file mode 100644
index 00000000..2d1ad4b0
--- /dev/null
+++ b/sound/core/device.c
@@ -0,0 +1,244 @@
+/*
+ * Device management routines
+ * Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/errno.h>
+#include <sound/core.h>
+
+/**
+ * snd_device_new - create an ALSA device component
+ * @card: the card instance
+ * @type: the device type, SNDRV_DEV_XXX
+ * @device_data: the data pointer of this device
+ * @ops: the operator table
+ *
+ * Creates a new device component for the given data pointer.
+ * The device will be assigned to the card and managed together
+ * by the card.
+ *
+ * The data pointer plays a role as the identifier, too, so the
+ * pointer address must be unique and unchanged.
+ *
+ * Returns zero if successful, or a negative error code on failure.
+ */
+int snd_device_new(struct snd_card *card, snd_device_type_t type,
+ void *device_data, struct snd_device_ops *ops)
+{
+ struct snd_device *dev;
+
+ if (snd_BUG_ON(!card || !device_data || !ops))
+ return -ENXIO;
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (dev == NULL) {
+ snd_printk(KERN_ERR "Cannot allocate device\n");
+ return -ENOMEM;
+ }
+ dev->card = card;
+ dev->type = type;
+ dev->state = SNDRV_DEV_BUILD;
+ dev->device_data = device_data;
+ dev->ops = ops;
+ list_add(&dev->list, &card->devices); /* add to the head of list */
+ return 0;
+}
+
+EXPORT_SYMBOL(snd_device_new);
+
+/**
+ * snd_device_free - release the device from the card
+ * @card: the card instance
+ * @device_data: the data pointer to release
+ *
+ * Removes the device from the list on the card and invokes the
+ * callbacks, dev_disconnect and dev_free, corresponding to the state.
+ * Then release the device.
+ *
+ * Returns zero if successful, or a negative error code on failure or if the
+ * device not found.
+ */
+int snd_device_free(struct snd_card *card, void *device_data)
+{
+ struct snd_device *dev;
+
+ if (snd_BUG_ON(!card || !device_data))
+ return -ENXIO;
+ list_for_each_entry(dev, &card->devices, list) {
+ if (dev->device_data != device_data)
+ continue;
+ /* unlink */
+ list_del(&dev->list);
+ if (dev->state == SNDRV_DEV_REGISTERED &&
+ dev->ops->dev_disconnect)
+ if (dev->ops->dev_disconnect(dev))
+ snd_printk(KERN_ERR
+ "device disconnect failure\n");
+ if (dev->ops->dev_free) {
+ if (dev->ops->dev_free(dev))
+ snd_printk(KERN_ERR "device free failure\n");
+ }
+ kfree(dev);
+ return 0;
+ }
+ snd_printd("device free %p (from %pF), not found\n", device_data,
+ __builtin_return_address(0));
+ return -ENXIO;
+}
+
+EXPORT_SYMBOL(snd_device_free);
+
+/**
+ * snd_device_disconnect - disconnect the device
+ * @card: the card instance
+ * @device_data: the data pointer to disconnect
+ *
+ * Turns the device into the disconnection state, invoking
+ * dev_disconnect callback, if the device was already registered.
+ *
+ * Usually called from snd_card_disconnect().
+ *
+ * Returns zero if successful, or a negative error code on failure or if the
+ * device not found.
+ */
+int snd_device_disconnect(struct snd_card *card, void *device_data)
+{
+ struct snd_device *dev;
+
+ if (snd_BUG_ON(!card || !device_data))
+ return -ENXIO;
+ list_for_each_entry(dev, &card->devices, list) {
+ if (dev->device_data != device_data)
+ continue;
+ if (dev->state == SNDRV_DEV_REGISTERED &&
+ dev->ops->dev_disconnect) {
+ if (dev->ops->dev_disconnect(dev))
+ snd_printk(KERN_ERR "device disconnect failure\n");
+ dev->state = SNDRV_DEV_DISCONNECTED;
+ }
+ return 0;
+ }
+ snd_printd("device disconnect %p (from %pF), not found\n", device_data,
+ __builtin_return_address(0));
+ return -ENXIO;
+}
+
+/**
+ * snd_device_register - register the device
+ * @card: the card instance
+ * @device_data: the data pointer to register
+ *
+ * Registers the device which was already created via
+ * snd_device_new(). Usually this is called from snd_card_register(),
+ * but it can be called later if any new devices are created after
+ * invocation of snd_card_register().
+ *
+ * Returns zero if successful, or a negative error code on failure or if the
+ * device not found.
+ */
+int snd_device_register(struct snd_card *card, void *device_data)
+{
+ struct snd_device *dev;
+ int err;
+
+ if (snd_BUG_ON(!card || !device_data))
+ return -ENXIO;
+ list_for_each_entry(dev, &card->devices, list) {
+ if (dev->device_data != device_data)
+ continue;
+ if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
+ if ((err = dev->ops->dev_register(dev)) < 0)
+ return err;
+ dev->state = SNDRV_DEV_REGISTERED;
+ return 0;
+ }
+ snd_printd("snd_device_register busy\n");
+ return -EBUSY;
+ }
+ snd_BUG();
+ return -ENXIO;
+}
+
+EXPORT_SYMBOL(snd_device_register);
+
+/*
+ * register all the devices on the card.
+ * called from init.c
+ */
+int snd_device_register_all(struct snd_card *card)
+{
+ struct snd_device *dev;
+ int err;
+
+ if (snd_BUG_ON(!card))
+ return -ENXIO;
+ list_for_each_entry(dev, &card->devices, list) {
+ if (dev->state == SNDRV_DEV_BUILD && dev->ops->dev_register) {
+ if ((err = dev->ops->dev_register(dev)) < 0)
+ return err;
+ dev->state = SNDRV_DEV_REGISTERED;
+ }
+ }
+ return 0;
+}
+
+/*
+ * disconnect all the devices on the card.
+ * called from init.c
+ */
+int snd_device_disconnect_all(struct snd_card *card)
+{
+ struct snd_device *dev;
+ int err = 0;
+
+ if (snd_BUG_ON(!card))
+ return -ENXIO;
+ list_for_each_entry(dev, &card->devices, list) {
+ if (snd_device_disconnect(card, dev->device_data) < 0)
+ err = -ENXIO;
+ }
+ return err;
+}
+
+/*
+ * release all the devices on the card.
+ * called from init.c
+ */
+int snd_device_free_all(struct snd_card *card, snd_device_cmd_t cmd)
+{
+ struct snd_device *dev;
+ int err;
+ unsigned int range_low, range_high, type;
+
+ if (snd_BUG_ON(!card))
+ return -ENXIO;
+ range_low = (__force unsigned int)cmd * SNDRV_DEV_TYPE_RANGE_SIZE;
+ range_high = range_low + SNDRV_DEV_TYPE_RANGE_SIZE - 1;
+ __again:
+ list_for_each_entry(dev, &card->devices, list) {
+ type = (__force unsigned int)dev->type;
+ if (type >= range_low && type <= range_high) {
+ if ((err = snd_device_free(card, dev->device_data)) < 0)
+ return err;
+ goto __again;
+ }
+ }
+ return 0;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-10 06:28:58 +0000