sound/aoa/core/snd-aoa-core.c

   1 /*
   2  * Apple Onboard Audio driver core
   3  *
   4  * Copyright 2006 Johannes Berg <johannes@sipsolutions.net>
   5  *
   6  * GPL v2, can be found in COPYING.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/list.h>
  12 #include "../aoa.h"
  13 #include "snd-aoa-alsa.h"
  14
  15 MODULE_DESCRIPTION("Apple Onboard Audio Sound Driver");
  16 MODULE_AUTHOR("Johannes Berg <johannes@sipsolutions.net>");
  17 MODULE_LICENSE("GPL");
  18
  19 /* We allow only one fabric. This simplifies things,
  20  * and more don't really make that much sense */
  21 static struct aoa_fabric *fabric;
  22 static LIST_HEAD(codec_list);
  23
  24 static int attach_codec_to_fabric(struct aoa_codec *c)
  25 {
  26         int err;
  27
  28         if (!try_module_get(c->owner))
  29                 return -EBUSY;
  30         /* found_codec has to be assigned */
  31         err = -ENOENT;
  32         if (fabric->found_codec)
  33                 err = fabric->found_codec(c);
  34         if (err) {
  35                 module_put(c->owner);
  36                 printk(KERN_ERR "snd-aoa: fabric didn't like codec %s\n",
  37                                 c->name);
  38                 return err;
  39         }
  40         c->fabric = fabric;
  41
  42         err = 0;
  43         if (c->init)
  44                 err = c->init(c);
  45         if (err) {
  46                 printk(KERN_ERR "snd-aoa: codec %s didn't init\n", c->name);
  47                 c->fabric = NULL;
  48                 if (fabric->remove_codec)
  49                         fabric->remove_codec(c);
  50                 module_put(c->owner);
  51                 return err;
  52         }
  53         if (fabric->attached_codec)
  54                 fabric->attached_codec(c);
  55         return 0;
  56 }
  57
  58 int aoa_codec_register(struct aoa_codec *codec)
  59 {
  60         int err = 0;
  61
  62         /* if there's a fabric already, we can tell if we
  63          * will want to have this codec, so propagate error
  64          * through. Otherwise, this will happen later... */
  65         if (fabric)
  66                 err = attach_codec_to_fabric(codec);
  67         if (!err)
  68                 list_add(&codec->list, &codec_list);
  69         return err;
  70 }
  71 EXPORT_SYMBOL_GPL(aoa_codec_register);
  72
  73 void aoa_codec_unregister(struct aoa_codec *codec)
  74 {
  75         list_del(&codec->list);
  76         if (codec->fabric && codec->exit)
  77                 codec->exit(codec);
  78         if (fabric && fabric->remove_codec)
  79                 fabric->remove_codec(codec);
  80         codec->fabric = NULL;
  81         module_put(codec->owner);
  82 }
  83 EXPORT_SYMBOL_GPL(aoa_codec_unregister);
  84
  85 int aoa_fabric_register(struct aoa_fabric *new_fabric)
  86 {
  87         struct aoa_codec *c;
  88         int err;
  89
  90         /* allow querying for presence of fabric
  91          * (i.e. do this test first!) */
  92         if (new_fabric == fabric) {
  93                 err = -EALREADY;
  94                 goto attach;
  95         }
  96         if (fabric)
  97                 return -EEXIST;
  98         if (!new_fabric)
  99                 return -EINVAL;
 100
 101         err = aoa_alsa_init(new_fabric->name, new_fabric->owner);
 102         if (err)
 103                 return err;
 104
 105         fabric = new_fabric;
 106
 107  attach:
 108         list_for_each_entry(c, &codec_list, list) {
 109                 if (c->fabric != fabric)
 110                         attach_codec_to_fabric(c);
 111         }
 112         return err;
 113 }
 114 EXPORT_SYMBOL_GPL(aoa_fabric_register);
 115
 116 void aoa_fabric_unregister(struct aoa_fabric *old_fabric)
 117 {
 118         struct aoa_codec *c;
 119
 120         if (fabric != old_fabric)
 121                 return;
 122
 123         list_for_each_entry(c, &codec_list, list) {
 124                 if (c->fabric)
 125                         aoa_fabric_unlink_codec(c);
 126         }
 127
 128         aoa_alsa_cleanup();
 129
 130         fabric = NULL;
 131 }
 132 EXPORT_SYMBOL_GPL(aoa_fabric_unregister);
 133
 134 void aoa_fabric_unlink_codec(struct aoa_codec *codec)
 135 {
 136         if (!codec->fabric) {
 137                 printk(KERN_ERR "snd-aoa: fabric unassigned "
 138                                 "in aoa_fabric_unlink_codec\n");
 139                 dump_stack();
 140                 return;
 141         }
 142         if (codec->exit)
 143                 codec->exit(codec);
 144         if (codec->fabric->remove_codec)
 145                 codec->fabric->remove_codec(codec);
 146         codec->fabric = NULL;
 147         module_put(codec->owner);
 148 }
 149 EXPORT_SYMBOL_GPL(aoa_fabric_unlink_codec);
 150
 151 static int __init aoa_init(void)
 152 {
 153         return 0;
 154 }
 155
 156 static void __exit aoa_exit(void)
 157 {
 158         aoa_alsa_cleanup();
 159 }
 160
 161 module_init(aoa_init);
 162 module_exit(aoa_exit);