keywest.c

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/*
 * common keywest i2c layer
 *
 * Copyright (c) by Takashi Iwai <[email protected]>
 *
 *   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 <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_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    i2c_set_clientdata(client, keywest_ctx);
    return 0;
}

/*
 * This is kind of a hack, best would be to turn powermac to fixed i2c
 * bus numbers and declare the sound device as part of platform
 * initialization
 */
static int keywest_attach_adapter(struct i2c_adapter *adapter)
{
    struct i2c_board_info info;

    if (! keywest_ctx)
        return -EINVAL;

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

    memset(&info, 0, sizeof(struct i2c_board_info));
    strlcpy(info.type, "keywest", I2C_NAME_SIZE);
    info.addr = keywest_ctx->addr;
    keywest_ctx->client = i2c_new_device(adapter, &info);
    if (!keywest_ctx->client)
        return -ENODEV;
    /*
     * We know the driver is already loaded, so the device should be
     * already bound. If not it means binding failed, and then there
     * is no point in keeping the device instantiated.
     */
    if (!keywest_ctx->client->driver) {
        i2c_unregister_device(keywest_ctx->client);
        keywest_ctx->client = NULL;
        return -ENODEV;
    }
    
    /*
     * Let i2c-core delete that device on driver removal.
     * This is safe because i2c-core holds the core_lock mutex for us.
     */
    list_add_tail(&keywest_ctx->client->detected,
              &keywest_ctx->client->driver->clients);
    return 0;
}

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

    return 0;
}


static const struct i2c_device_id keywest_i2c_id[] = {
    { "keywest", 0 },
    { }
};

static struct i2c_driver keywest_driver = {
    .driver = {
        .name = "PMac Keywest Audio",
    },
    .attach_adapter = keywest_attach_adapter,
    .probe = keywest_probe,
    .remove = keywest_remove,
    .id_table = keywest_i2c_id,
};

/* 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 __devinit 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 __devinit 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;
}