311 lines
7.1 KiB
C
311 lines
7.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* ALSA sequencer device management
|
|
* Copyright (c) 1999 by Takashi Iwai <tiwai@suse.de>
|
|
*
|
|
*----------------------------------------------------------------
|
|
*
|
|
* 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);
|
|
|
|
static inline void cancel_autoload_drivers(void)
|
|
{
|
|
cancel_work_sync(&autoload_work);
|
|
}
|
|
#else
|
|
static inline void queue_autoload_drivers(void)
|
|
{
|
|
}
|
|
|
|
static inline void cancel_autoload_drivers(void)
|
|
{
|
|
}
|
|
#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();
|
|
if (dev->private_free)
|
|
dev->private_free(dev);
|
|
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)
|
|
{
|
|
kfree(to_seq_dev(dev));
|
|
}
|
|
|
|
/*
|
|
* 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 const 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)
|