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}