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 #include <sound/ac97_codec.h>
  19
  20 /*
  21  * Let drivers decide whether they want to support given codec from their
  22  * probe method.  Drivers have direct access to the struct snd_ac97 structure and may
  23  * decide based on the id field amongst other things.
  24  */
  25 static int ac97_bus_match(struct device *dev, struct device_driver *drv)
  26 {
  27         return 1;
  28 }
  29
  30 #ifdef CONFIG_PM
  31 static int ac97_bus_suspend(struct device *dev, pm_message_t state)
  32 {
  33         int ret = 0;
  34
  35         if (dev->driver && dev->driver->suspend)
  36                 ret = dev->driver->suspend(dev, state);
  37
  38         return ret;
  39 }
  40
  41 static int ac97_bus_resume(struct device *dev)
  42 {
  43         int ret = 0;
  44
  45         if (dev->driver && dev->driver->resume)
  46                 ret = dev->driver->resume(dev);
  47
  48         return ret;
  49 }
  50 #endif /* CONFIG_PM */
  51
  52 struct bus_type ac97_bus_type = {
  53         .name           = "ac97",
  54         .match          = ac97_bus_match,
  55 #ifdef CONFIG_PM
  56         .suspend        = ac97_bus_suspend,
  57         .resume         = ac97_bus_resume,
  58 #endif /* CONFIG_PM */
  59 };
  60
  61 static int __init ac97_bus_init(void)
  62 {
  63         return bus_register(&ac97_bus_type);
  64 }
  65
  66 subsys_initcall(ac97_bus_init);
  67
  68 static void __exit ac97_bus_exit(void)
  69 {
  70         bus_unregister(&ac97_bus_type);
  71 }
  72
  73 module_exit(ac97_bus_exit);
  74
  75 EXPORT_SYMBOL(ac97_bus_type);
  76
  77 MODULE_LICENSE("GPL");