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keywest.c

/*
 * common keywest i2c layer
 *
 * Copyright (c) by Takashi Iwai <tiwai@suse.de>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */


#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <sound/core.h>
#include "pmac.h"

/*
 * we have to keep a static variable here since i2c attach_adapter
 * callback cannot pass a private data.
 */
static struct pmac_keywest *keywest_ctx;


static int keywest_attach_adapter(struct i2c_adapter *adapter);
static int keywest_detach_client(struct i2c_client *client);

struct i2c_driver keywest_driver = {  
      .driver = {
            .name = "PMac Keywest Audio",
      },
      .attach_adapter = &keywest_attach_adapter,
      .detach_client = &keywest_detach_client,
};


#ifndef i2c_device_name
#define i2c_device_name(x)    ((x)->name)
#endif

static int keywest_attach_adapter(struct i2c_adapter *adapter)
{
      int err;
      struct i2c_client *new_client;

      if (! keywest_ctx)
            return -EINVAL;

      if (strncmp(i2c_device_name(adapter), "mac-io", 6))
            return 0; /* ignored */

      new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
      if (! new_client)
            return -ENOMEM;

      new_client->addr = keywest_ctx->addr;
      i2c_set_clientdata(new_client, keywest_ctx);
      new_client->adapter = adapter;
      new_client->driver = &keywest_driver;
      new_client->flags = 0;

      strcpy(i2c_device_name(new_client), keywest_ctx->name);
      keywest_ctx->client = new_client;
      
      /* Tell the i2c layer a new client has arrived */
      if (i2c_attach_client(new_client)) {
            snd_printk(KERN_ERR "tumbler: cannot attach i2c client\n");
            err = -ENODEV;
            goto __err;
      }

      return 0;

 __err:
      kfree(new_client);
      keywest_ctx->client = NULL;
      return err;
}

static int keywest_detach_client(struct i2c_client *client)
{
      if (! keywest_ctx)
            return 0;
      if (client == keywest_ctx->client)
            keywest_ctx->client = NULL;

      i2c_detach_client(client);
      kfree(client);
      return 0;
}

/* exported */
void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
{
      if (keywest_ctx && keywest_ctx == i2c) {
            i2c_del_driver(&keywest_driver);
            keywest_ctx = NULL;
      }
}

int __init snd_pmac_tumbler_post_init(void)
{
      int err;
      
      if (!keywest_ctx || !keywest_ctx->client)
            return -ENXIO;

      if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
            snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
            return err;
      }
      return 0;
}

/* exported */
int __init snd_pmac_keywest_init(struct pmac_keywest *i2c)
{
      int err;

      if (keywest_ctx)
            return -EBUSY;

      keywest_ctx = i2c;

      if ((err = i2c_add_driver(&keywest_driver))) {
            snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
            return err;
      }
      return 0;
}

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