sound/ac97_bus.c

   1 /*
   2  * Linux driver model AC97 bus interface
   3  *
   4  * Author:      Nicolas Pitre
   5  * Created:     Jan 14, 2005
   6  * Copyright:   (C) MontaVista Software Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/string.h>
  18
  19 /*
  20  * Let drivers decide whether they want to support given codec from their
  21  * probe method.  Drivers have direct access to the struct snd_ac97 structure and may
  22  * decide based on the id field amongst other things.
  23  */
  24 static int ac97_bus_match(struct device *dev, struct device_driver *drv)
  25 {
  26         return 1;
  27 }
  28
  29 #ifdef CONFIG_PM
  30 static int ac97_bus_suspend(struct device *dev, pm_message_t state)
  31 {
  32         int ret = 0;
  33
  34         if (dev->driver && dev->driver->suspend)
  35                 ret = dev->driver->suspend(dev, state);
  36
  37         return ret;
  38 }
  39
  40 static int ac97_bus_resume(struct device *dev)
  41 {
  42         int ret = 0;
  43
  44         if (dev->driver && dev->driver->resume)
  45                 ret = dev->driver->resume(dev);
  46
  47         return ret;
  48 }
  49 #endif /* CONFIG_PM */
  50
  51 struct bus_type ac97_bus_type = {
  52         .name           = "ac97",
  53         .match          = ac97_bus_match,
  54 #ifdef CONFIG_PM
  55         .suspend        = ac97_bus_suspend,
  56         .resume         = ac97_bus_resume,
  57 #endif /* CONFIG_PM */
  58 };
  59
  60 static int __init ac97_bus_init(void)
  61 {
  62         return bus_register(&ac97_bus_type);
  63 }
  64
  65 subsys_initcall(ac97_bus_init);
  66
  67 static void __exit ac97_bus_exit(void)
  68 {
  69         bus_unregister(&ac97_bus_type);
  70 }
  71
  72 module_exit(ac97_bus_exit);
  73
  74 EXPORT_SYMBOL(ac97_bus_type);
  75
  76 MODULE_LICENSE("GPL");