linux/sound/ppc/keywest.c
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   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 */
  32static struct pmac_keywest *keywest_ctx;
  33
  34
  35static 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 */
  47static 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
  83static int keywest_remove(struct i2c_client *client)
  84{
  85        if (! keywest_ctx)
  86                return 0;
  87        if (client == keywest_ctx->client)
  88                keywest_ctx->client = NULL;
  89
  90        return 0;
  91}
  92
  93
  94static const struct i2c_device_id keywest_i2c_id[] = {
  95        { "keywest", 0 },
  96        { }
  97};
  98
  99static struct i2c_driver keywest_driver = {
 100        .driver = {
 101                .name = "PMac Keywest Audio",
 102        },
 103        .attach_adapter = keywest_attach_adapter,
 104        .probe = keywest_probe,
 105        .remove = keywest_remove,
 106        .id_table = keywest_i2c_id,
 107};
 108
 109/* exported */
 110void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 111{
 112        if (keywest_ctx && keywest_ctx == i2c) {
 113                i2c_del_driver(&keywest_driver);
 114                keywest_ctx = NULL;
 115        }
 116}
 117
 118int __devinit snd_pmac_tumbler_post_init(void)
 119{
 120        int err;
 121        
 122        if (!keywest_ctx || !keywest_ctx->client)
 123                return -ENXIO;
 124
 125        if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 126                snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 127                return err;
 128        }
 129        return 0;
 130}
 131
 132/* exported */
 133int __devinit snd_pmac_keywest_init(struct pmac_keywest *i2c)
 134{
 135        int err;
 136
 137        if (keywest_ctx)
 138                return -EBUSY;
 139
 140        keywest_ctx = i2c;
 141
 142        if ((err = i2c_add_driver(&keywest_driver))) {
 143                snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 144                return err;
 145        }
 146        return 0;
 147}
 148
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