/* * ALSA sequencer device management * Copyright (c) 1999 by Takashi Iwai * * 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 #include #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Takashi Iwai "); 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); #define cancel_autoload_drivers() cancel_work_sync(&autoload_work) #else #define queue_autoload_drivers() /* NOP */ #define cancel_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; cancel_autoload_drivers(); 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)