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/module.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 static bool keywest_probed;
  36
  37 static int keywest_probe(struct i2c_client *client,
  38                          const struct i2c_device_id *id)
  39 {
  40         keywest_probed = true;
  41         /* If instantiated via i2c-powermac, we still need to set the client */
  42         if (!keywest_ctx->client)
  43                 keywest_ctx->client = client;
  44         i2c_set_clientdata(client, keywest_ctx);
  45         return 0;
  46 }
  47
  48 /*
  49  * This is kind of a hack, best would be to turn powermac to fixed i2c
  50  * bus numbers and declare the sound device as part of platform
  51  * initialization
  52  */
  53 static int keywest_attach_adapter(struct i2c_adapter *adapter)
  54 {
  55         struct i2c_board_info info;
  56
  57         if (! keywest_ctx)
  58                 return -EINVAL;
  59
  60         if (strncmp(adapter->name, "mac-io", 6))
  61                 return -EINVAL; /* ignored */
  62
  63         memset(&info, 0, sizeof(struct i2c_board_info));
  64         strlcpy(info.type, "keywest", I2C_NAME_SIZE);
  65         info.addr = keywest_ctx->addr;
  66         keywest_ctx->client = i2c_new_device(adapter, &info);
  67         if (!keywest_ctx->client)
  68                 return -ENODEV;
  69         /*
  70          * We know the driver is already loaded, so the device should be
  71          * already bound. If not it means binding failed, and then there
  72          * is no point in keeping the device instantiated.
  73          */
  74         if (!keywest_ctx->client->dev.driver) {
  75                 i2c_unregister_device(keywest_ctx->client);
  76                 keywest_ctx->client = NULL;
  77                 return -ENODEV;
  78         }
  79
  80         /*
  81          * Let i2c-core delete that device on driver removal.
  82          * This is safe because i2c-core holds the core_lock mutex for us.
  83          */
  84         list_add_tail(&keywest_ctx->client->detected,
  85                       &to_i2c_driver(keywest_ctx->client->dev.driver)->clients);
  86         return 0;
  87 }
  88
  89 static int keywest_remove(struct i2c_client *client)
  90 {
  91         if (! keywest_ctx)
  92                 return 0;
  93         if (client == keywest_ctx->client)
  94                 keywest_ctx->client = NULL;
  95
  96         return 0;
  97 }
  98
  99
 100 static const struct i2c_device_id keywest_i2c_id[] = {
 101         { "MAC,tas3004", 0 },           /* instantiated by i2c-powermac */
 102         { "keywest", 0 },               /* instantiated by us if needed */
 103         { }
 104 };
 105 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
 106
 107 static struct i2c_driver keywest_driver = {
 108         .driver = {
 109                 .name = "PMac Keywest Audio",
 110         },
 111         .probe = keywest_probe,
 112         .remove = keywest_remove,
 113         .id_table = keywest_i2c_id,
 114 };
 115
 116 /* exported */
 117 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 118 {
 119         if (keywest_ctx && keywest_ctx == i2c) {
 120                 i2c_del_driver(&keywest_driver);
 121                 keywest_ctx = NULL;
 122         }
 123 }
 124
 125 int snd_pmac_tumbler_post_init(void)
 126 {
 127         int err;
 128
 129         if (!keywest_ctx || !keywest_ctx->client)
 130                 return -ENXIO;
 131
 132         if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 133                 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 134                 return err;
 135         }
 136         return 0;
 137 }
 138
 139 /* exported */
 140 int snd_pmac_keywest_init(struct pmac_keywest *i2c)
 141 {
 142         struct i2c_adapter *adap;
 143         int err, i = 0;
 144
 145         if (keywest_ctx)
 146                 return -EBUSY;
 147
 148         adap = i2c_get_adapter(0);
 149         if (!adap)
 150                 return -EPROBE_DEFER;
 151
 152         keywest_ctx = i2c;
 153
 154         if ((err = i2c_add_driver(&keywest_driver))) {
 155                 snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 156                 i2c_put_adapter(adap);
 157                 return err;
 158         }
 159
 160         /* There was already a device from i2c-powermac. Great, let's return */
 161         if (keywest_probed)
 162                 return 0;
 163
 164         /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 165         while (adap) {
 166                 /* Scan for devices to be bound to */
 167                 err = keywest_attach_adapter(adap);
 168                 if (!err)
 169                         return 0;
 170                 i2c_put_adapter(adap);
 171                 adap = i2c_get_adapter(++i);
 172         }
 173
 174         return -ENODEV;
 175 }