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 <linux/slab.h>
  26 #include <sound/core.h>
  27 #include "pmac.h"
  28
  29 /*
  30  * we have to keep a static variable here since i2c attach_adapter
  31  * callback cannot pass a private data.
  32  */
  33 static struct pmac_keywest *keywest_ctx;
  34
  35
  36 static int keywest_probe(struct i2c_client *client,
  37                          const struct i2c_device_id *id)
  38 {
  39         i2c_set_clientdata(client, keywest_ctx);
  40         return 0;
  41 }
  42
  43 /*
  44  * This is kind of a hack, best would be to turn powermac to fixed i2c
  45  * bus numbers and declare the sound device as part of platform
  46  * initialization
  47  */
  48 static int keywest_attach_adapter(struct i2c_adapter *adapter)
  49 {
  50         struct i2c_board_info info;
  51
  52         if (! keywest_ctx)
  53                 return -EINVAL;
  54
  55         if (strncmp(adapter->name, "mac-io", 6))
  56                 return 0; /* ignored */
  57
  58         memset(&info, 0, sizeof(struct i2c_board_info));
  59         strlcpy(info.type, "keywest", I2C_NAME_SIZE);
  60         info.addr = keywest_ctx->addr;
  61         keywest_ctx->client = i2c_new_device(adapter, &info);
  62         if (!keywest_ctx->client)
  63                 return -ENODEV;
  64         /*
  65          * We know the driver is already loaded, so the device should be
  66          * already bound. If not it means binding failed, and then there
  67          * is no point in keeping the device instantiated.
  68          */
  69         if (!keywest_ctx->client->driver) {
  70                 i2c_unregister_device(keywest_ctx->client);
  71                 keywest_ctx->client = NULL;
  72                 return -ENODEV;
  73         }
  74
  75         /*
  76          * Let i2c-core delete that device on driver removal.
  77          * This is safe because i2c-core holds the core_lock mutex for us.
  78          */
  79         list_add_tail(&keywest_ctx->client->detected,
  80                       &keywest_ctx->client->driver->clients);
  81         return 0;
  82 }
  83
  84 static int keywest_remove(struct i2c_client *client)
  85 {
  86         i2c_set_clientdata(client, NULL);
  87         if (! keywest_ctx)
  88                 return 0;
  89         if (client == keywest_ctx->client)
  90                 keywest_ctx->client = NULL;
  91
  92         return 0;
  93 }
  94
  95
  96 static const struct i2c_device_id keywest_i2c_id[] = {
  97         { "keywest", 0 },
  98         { }
  99 };
 100
 101 static struct i2c_driver keywest_driver = {
 102         .driver = {
 103                 .name = "PMac Keywest Audio",
 104         },
 105         .attach_adapter = keywest_attach_adapter,
 106         .probe = keywest_probe,
 107         .remove = keywest_remove,
 108         .id_table = keywest_i2c_id,
 109 };
 110
 111 /* exported */
 112 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 113 {
 114         if (keywest_ctx && keywest_ctx == i2c) {
 115                 i2c_del_driver(&keywest_driver);
 116                 keywest_ctx = NULL;
 117         }
 118 }
 119
 120 int __devinit snd_pmac_tumbler_post_init(void)
 121 {
 122         int err;
 123
 124         if (!keywest_ctx || !keywest_ctx->client)
 125                 return -ENXIO;
 126
 127         if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 128                 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 129                 return err;
 130         }
 131         return 0;
 132 }
 133
 134 /* exported */
 135 int __devinit snd_pmac_keywest_init(struct pmac_keywest *i2c)
 136 {
 137         int err;
 138
 139         if (keywest_ctx)
 140                 return -EBUSY;
 141
 142         keywest_ctx = i2c;
 143
 144         if ((err = i2c_add_driver(&keywest_driver))) {
 145                 snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 146                 return err;
 147         }
 148         return 0;
 149 }