LXR linux/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 */
  33static struct pmac_keywest *keywest_ctx;
  34
  35static bool keywest_probed;
  36
  37static 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 */
  53static 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
  89static 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
 100static 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};
 105MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
 106
 107static 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 */
 117void 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
 125int 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 */
 140int 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}
 176