1 files changed, 315 insertions, 0 deletions

diff --git a/sound/core/seq_device.c b/sound/core/seq_device.c
new file mode 100644
index 000000000000..c4acf17e9f5e
--- /dev/null
+++ b/sound/core/seq_device.c
@@ -0,0 +1,315 @@
+/*
+ *  ALSA sequencer device management
+ *  Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
+ *
+ *   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
+ *
+ *
+ *----------------------------------------------------------------
+ *
+ * This device handler separates the card driver module from sequencer
+ * stuff (sequencer core, synth drivers, etc), so that user can avoid
+ * to spend unnecessary resources e.g. if he needs only listening to
+ * MP3s.
+ *
+ * The card (or lowlevel) driver creates a sequencer device entry
+ * via snd_seq_device_new().  This is an entry pointer to communicate
+ * with the sequencer device "driver", which is involved with the
+ * actual part to communicate with the sequencer core.
+ * Each sequencer device entry has an id string and the corresponding
+ * driver with the same id is loaded when required.  For example,
+ * lowlevel codes to access emu8000 chip on sbawe card are included in
+ * emu8000-synth module.  To activate this module, the hardware
+ * resources like i/o port are passed via snd_seq_device argument.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <sound/core.h>
+#include <sound/info.h>
+#include <sound/seq_device.h>
+#include <sound/seq_kernel.h>
+#include <sound/initval.h>
+#include <linux/kmod.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+
+MODULE_AUTHOR("Takashi Iwai <tiwai@suse.de>");
+MODULE_DESCRIPTION("ALSA sequencer device management");
+MODULE_LICENSE("GPL");
+
+/*
+ * bus definition
+ */
+static int snd_seq_bus_match(struct device *dev, struct device_driver *drv)
+{
+        struct snd_seq_device *sdev = to_seq_dev(dev);
+        struct snd_seq_driver *sdrv = to_seq_drv(drv);
+
+        return strcmp(sdrv->id, sdev->id) == 0 &&
+                sdrv->argsize == sdev->argsize;
+}
+
+static struct bus_type snd_seq_bus_type = {
+        .name = "snd_seq",
+        .match = snd_seq_bus_match,
+};
+
+/*
+ * proc interface -- just for compatibility
+ */
+#ifdef CONFIG_SND_PROC_FS
+static struct snd_info_entry *info_entry;
+
+static int print_dev_info(struct device *dev, void *data)
+{
+        struct snd_seq_device *sdev = to_seq_dev(dev);
+        struct snd_info_buffer *buffer = data;
+
+        snd_iprintf(buffer, "snd-%s,%s,%d\n", sdev->id,
+                    dev->driver ? "loaded" : "empty",
+                    dev->driver ? 1 : 0);
+        return 0;
+}
+
+static void snd_seq_device_info(struct snd_info_entry *entry,
+                                struct snd_info_buffer *buffer)
+{
+        bus_for_each_dev(&snd_seq_bus_type, NULL, buffer, print_dev_info);
+}
+#endif
+
+/*
+ * load all registered drivers (called from seq_clientmgr.c)
+ */
+
+#ifdef CONFIG_MODULES
+/* flag to block auto-loading */
+static atomic_t snd_seq_in_init = ATOMIC_INIT(1); /* blocked as default */
+
+static int request_seq_drv(struct device *dev, void *data)
+{
+        struct snd_seq_device *sdev = to_seq_dev(dev);
+
+        if (!dev->driver)
+                request_module("snd-%s", sdev->id);
+        return 0;
+}
+
+static void autoload_drivers(struct work_struct *work)
+{
+        /* avoid reentrance */
+        if (atomic_inc_return(&snd_seq_in_init) == 1)
+                bus_for_each_dev(&snd_seq_bus_type, NULL, NULL,
+                                 request_seq_drv);
+        atomic_dec(&snd_seq_in_init);
+}
+
+static DECLARE_WORK(autoload_work, autoload_drivers);
+
+static void queue_autoload_drivers(void)
+{
+        schedule_work(&autoload_work);
+}
+
+void snd_seq_autoload_init(void)
+{
+        atomic_dec(&snd_seq_in_init);
+#ifdef CONFIG_SND_SEQUENCER_MODULE
+        /* initial autoload only when snd-seq is a module */
+        queue_autoload_drivers();
+#endif
+}
+EXPORT_SYMBOL(snd_seq_autoload_init);
+
+void snd_seq_autoload_exit(void)
+{
+        atomic_inc(&snd_seq_in_init);
+}
+EXPORT_SYMBOL(snd_seq_autoload_exit);
+
+void snd_seq_device_load_drivers(void)
+{
+        queue_autoload_drivers();
+        flush_work(&autoload_work);
+}
+EXPORT_SYMBOL(snd_seq_device_load_drivers);
+#else
+#define queue_autoload_drivers() /* NOP */
+#endif
+
+/*
+ * device management
+ */
+static int snd_seq_device_dev_free(struct snd_device *device)
+{
+        struct snd_seq_device *dev = device->device_data;
+
+        put_device(&dev->dev);
+        return 0;
+}
+
+static int snd_seq_device_dev_register(struct snd_device *device)
+{
+        struct snd_seq_device *dev = device->device_data;
+        int err;
+
+        err = device_add(&dev->dev);
+        if (err < 0)
+                return err;
+        if (!dev->dev.driver)
+                queue_autoload_drivers();
+        return 0;
+}
+
+static int snd_seq_device_dev_disconnect(struct snd_device *device)
+{
+        struct snd_seq_device *dev = device->device_data;
+
+        device_del(&dev->dev);
+        return 0;
+}
+
+static void snd_seq_dev_release(struct device *dev)
+{
+        struct snd_seq_device *sdev = to_seq_dev(dev);
+
+        if (sdev->private_free)
+                sdev->private_free(sdev);
+        kfree(sdev);
+}
+
+/*
+ * register a sequencer device
+ * card = card info
+ * device = device number (if any)
+ * id = id of driver
+ * result = return pointer (NULL allowed if unnecessary)
+ */
+int snd_seq_device_new(struct snd_card *card, int device, const char *id,
+                       int argsize, struct snd_seq_device **result)
+{
+        struct snd_seq_device *dev;
+        int err;
+        static struct snd_device_ops dops = {
+                .dev_free = snd_seq_device_dev_free,
+                .dev_register = snd_seq_device_dev_register,
+                .dev_disconnect = snd_seq_device_dev_disconnect,
+        };
+
+        if (result)
+                *result = NULL;
+
+        if (snd_BUG_ON(!id))
+                return -EINVAL;
+
+        dev = kzalloc(sizeof(*dev) + argsize, GFP_KERNEL);
+        if (!dev)
+                return -ENOMEM;
+
+        /* set up device info */
+        dev->card = card;
+        dev->device = device;
+        dev->id = id;
+        dev->argsize = argsize;
+
+        device_initialize(&dev->dev);
+        dev->dev.parent = &card->card_dev;
+        dev->dev.bus = &snd_seq_bus_type;
+        dev->dev.release = snd_seq_dev_release;
+        dev_set_name(&dev->dev, "%s-%d-%d", dev->id, card->number, device);
+
+        /* add this device to the list */
+        err = snd_device_new(card, SNDRV_DEV_SEQUENCER, dev, &dops);
+        if (err < 0) {
+                put_device(&dev->dev);
+                return err;
+        }
+        
+        if (result)
+                *result = dev;
+
+        return 0;
+}
+EXPORT_SYMBOL(snd_seq_device_new);
+
+/*
+ * driver registration
+ */
+int __snd_seq_driver_register(struct snd_seq_driver *drv, struct module *mod)
+{
+        if (WARN_ON(!drv->driver.name || !drv->id))
+                return -EINVAL;
+        drv->driver.bus = &snd_seq_bus_type;
+        drv->driver.owner = mod;
+        return driver_register(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(__snd_seq_driver_register);
+
+void snd_seq_driver_unregister(struct snd_seq_driver *drv)
+{
+        driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(snd_seq_driver_unregister);
+
+/*
+ * module part
+ */
+
+static int __init seq_dev_proc_init(void)
+{
+#ifdef CONFIG_SND_PROC_FS
+        info_entry = snd_info_create_module_entry(THIS_MODULE, "drivers",
+                                                  snd_seq_root);
+        if (info_entry == NULL)
+                return -ENOMEM;
+        info_entry->content = SNDRV_INFO_CONTENT_TEXT;
+        info_entry->c.text.read = snd_seq_device_info;
+        if (snd_info_register(info_entry) < 0) {
+                snd_info_free_entry(info_entry);
+                return -ENOMEM;
+        }
+#endif
+        return 0;
+}
+
+static int __init alsa_seq_device_init(void)
+{
+        int err;
+
+        err = bus_register(&snd_seq_bus_type);
+        if (err < 0)
+                return err;
+        err = seq_dev_proc_init();
+        if (err < 0)
+                bus_unregister(&snd_seq_bus_type);
+        return err;
+}
+
+static void __exit alsa_seq_device_exit(void)
+{
+#ifdef CONFIG_MODULES
+        cancel_work_sync(&autoload_work);
+#endif
+#ifdef CONFIG_SND_PROC_FS
+        snd_info_free_entry(info_entry);
+#endif
+        bus_unregister(&snd_seq_bus_type);
+}
+
+subsys_initcall(alsa_seq_device_init)
+module_exit(alsa_seq_device_exit)