release/src-rt-6.x.4708/linux/linux-2.6.36/sound/ppc/keywest.c

   1 /*
   2  * common keywest i2c layer
   3  *
   4  * Copyright (c) by Takashi Iwai <tiwai@suse.de>
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation; either version 2 of the License, or
   9  *   (at your option) any later version.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  */
  20
  21
  22 #include <linux/init.h>
  23 #include <linux/i2c.h>
  24 #include <linux/delay.h>
  25 #include <sound/core.h>
  26 #include "pmac.h"
  27
  28 /*
  29  * we have to keep a static variable here since i2c attach_adapter
  30  * callback cannot pass a private data.
  31  */
  32 static struct pmac_keywest *keywest_ctx;
  33
  34
  35 static int keywest_probe(struct i2c_client *client,
  36                          const struct i2c_device_id *id)
  37 {
  38         i2c_set_clientdata(client, keywest_ctx);
  39         return 0;
  40 }
  41
  42 /*
  43  * This is kind of a hack, best would be to turn powermac to fixed i2c
  44  * bus numbers and declare the sound device as part of platform
  45  * initialization
  46  */
  47 static int keywest_attach_adapter(struct i2c_adapter *adapter)
  48 {
  49         struct i2c_board_info info;
  50
  51         if (! keywest_ctx)
  52                 return -EINVAL;
  53
  54         if (strncmp(adapter->name, "mac-io", 6))
  55                 return 0; /* ignored */
  56
  57         memset(&info, 0, sizeof(struct i2c_board_info));
  58         strlcpy(info.type, "keywest", I2C_NAME_SIZE);
  59         info.addr = keywest_ctx->addr;
  60         keywest_ctx->client = i2c_new_device(adapter, &info);
  61         if (!keywest_ctx->client)
  62                 return -ENODEV;
  63         /*
  64          * We know the driver is already loaded, so the device should be
  65          * already bound. If not it means binding failed, and then there
  66          * is no point in keeping the device instantiated.
  67          */
  68         if (!keywest_ctx->client->driver) {
  69                 i2c_unregister_device(keywest_ctx->client);
  70                 keywest_ctx->client = NULL;
  71                 return -ENODEV;
  72         }
  73
  74         /*
  75          * Let i2c-core delete that device on driver removal.
  76          * This is safe because i2c-core holds the core_lock mutex for us.
  77          */
  78         list_add_tail(&keywest_ctx->client->detected,
  79                       &keywest_ctx->client->driver->clients);
  80         return 0;
  81 }
  82
  83 static int keywest_remove(struct i2c_client *client)
  84 {
  85         i2c_set_clientdata(client, NULL);
  86         if (! keywest_ctx)
  87                 return 0;
  88         if (client == keywest_ctx->client)
  89                 keywest_ctx->client = NULL;
  90
  91         return 0;
  92 }
  93
  94
  95 static const struct i2c_device_id keywest_i2c_id[] = {
  96         { "keywest", 0 },
  97         { }
  98 };
  99
 100 static struct i2c_driver keywest_driver = {
 101         .driver = {
 102                 .name = "PMac Keywest Audio",
 103         },
 104         .attach_adapter = keywest_attach_adapter,
 105         .probe = keywest_probe,
 106         .remove = keywest_remove,
 107         .id_table = keywest_i2c_id,
 108 };
 109
 110 /* exported */
 111 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 112 {
 113         if (keywest_ctx && keywest_ctx == i2c) {
 114                 i2c_del_driver(&keywest_driver);
 115                 keywest_ctx = NULL;
 116         }
 117 }
 118
 119 int __devinit snd_pmac_tumbler_post_init(void)
 120 {
 121         int err;
 122
 123         if (!keywest_ctx || !keywest_ctx->client)
 124                 return -ENXIO;
 125
 126         if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 127                 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 128                 return err;
 129         }
 130         return 0;
 131 }
 132
 133 /* exported */
 134 int __devinit snd_pmac_keywest_init(struct pmac_keywest *i2c)
 135 {
 136         int err;
 137
 138         if (keywest_ctx)
 139                 return -EBUSY;
 140
 141         keywest_ctx = i2c;
 142
 143         if ((err = i2c_add_driver(&keywest_driver))) {
 144                 snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 145                 return err;
 146         }
 147         return 0;
 148 }