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 static bool keywest_probed;
  35
  36 static int keywest_probe(struct i2c_client *client,
  37                          const struct i2c_device_id *id)
  38 {
  39         keywest_probed = true;
  40         /* If instantiated via i2c-powermac, we still need to set the client */
  41         if (!keywest_ctx->client)
  42                 keywest_ctx->client = client;
  43         i2c_set_clientdata(client, keywest_ctx);
  44         return 0;
  45 }
  46
  47 /*
  48  * This is kind of a hack, best would be to turn powermac to fixed i2c
  49  * bus numbers and declare the sound device as part of platform
  50  * initialization
  51  */
  52 static int keywest_attach_adapter(struct i2c_adapter *adapter)
  53 {
  54         struct i2c_board_info info;
  55
  56         if (! keywest_ctx)
  57                 return -EINVAL;
  58
  59         if (strncmp(adapter->name, "mac-io", 6))
  60                 return -EINVAL; /* ignored */
  61
  62         memset(&info, 0, sizeof(struct i2c_board_info));
  63         strlcpy(info.type, "keywest", I2C_NAME_SIZE);
  64         info.addr = keywest_ctx->addr;
  65         keywest_ctx->client = i2c_new_device(adapter, &info);
  66         if (!keywest_ctx->client)
  67                 return -ENODEV;
  68         /*
  69          * We know the driver is already loaded, so the device should be
  70          * already bound. If not it means binding failed, and then there
  71          * is no point in keeping the device instantiated.
  72          */
  73         if (!keywest_ctx->client->dev.driver) {
  74                 i2c_unregister_device(keywest_ctx->client);
  75                 keywest_ctx->client = NULL;
  76                 return -ENODEV;
  77         }
  78
  79         /*
  80          * Let i2c-core delete that device on driver removal.
  81          * This is safe because i2c-core holds the core_lock mutex for us.
  82          */
  83         list_add_tail(&keywest_ctx->client->detected,
  84                       &to_i2c_driver(keywest_ctx->client->dev.driver)->clients);
  85         return 0;
  86 }
  87
  88 static int keywest_remove(struct i2c_client *client)
  89 {
  90         if (! keywest_ctx)
  91                 return 0;
  92         if (client == keywest_ctx->client)
  93                 keywest_ctx->client = NULL;
  94
  95         return 0;
  96 }
  97
  98
  99 static const struct i2c_device_id keywest_i2c_id[] = {
 100         { "MAC,tas3004", 0 },           /* instantiated by i2c-powermac */
 101         { "keywest", 0 },               /* instantiated by us if needed */
 102         { }
 103 };
 104
 105 static struct i2c_driver keywest_driver = {
 106         .driver = {
 107                 .name = "PMac Keywest Audio",
 108         },
 109         .probe = keywest_probe,
 110         .remove = keywest_remove,
 111         .id_table = keywest_i2c_id,
 112 };
 113
 114 /* exported */
 115 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 116 {
 117         if (keywest_ctx && keywest_ctx == i2c) {
 118                 i2c_del_driver(&keywest_driver);
 119                 keywest_ctx = NULL;
 120         }
 121 }
 122
 123 int snd_pmac_tumbler_post_init(void)
 124 {
 125         int err;
 126
 127         if (!keywest_ctx || !keywest_ctx->client)
 128                 return -ENXIO;
 129
 130         if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 131                 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 132                 return err;
 133         }
 134         return 0;
 135 }
 136
 137 /* exported */
 138 int snd_pmac_keywest_init(struct pmac_keywest *i2c)
 139 {
 140         struct i2c_adapter *adap;
 141         int err, i = 0;
 142
 143         if (keywest_ctx)
 144                 return -EBUSY;
 145
 146         adap = i2c_get_adapter(0);
 147         if (!adap)
 148                 return -EPROBE_DEFER;
 149
 150         keywest_ctx = i2c;
 151
 152         if ((err = i2c_add_driver(&keywest_driver))) {
 153                 snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 154                 i2c_put_adapter(adap);
 155                 return err;
 156         }
 157
 158         /* There was already a device from i2c-powermac. Great, let's return */
 159         if (keywest_probed)
 160                 return 0;
 161
 162         /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 163         while (adap) {
 164                 /* Scan for devices to be bound to */
 165                 err = keywest_attach_adapter(adap);
 166                 if (!err)
 167                         return 0;
 168                 i2c_put_adapter(adap);
 169                 adap = i2c_get_adapter(++i);
 170         }
 171
 172         return -ENODEV;
 173 }