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