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  */
32 static struct pmac_keywest *keywest_ctx;
33 
34 
keywest_probe(struct i2c_client * client,const struct i2c_device_id * id)35 static 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  */
keywest_attach_adapter(struct i2c_adapter * adapter)47 static 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 
keywest_remove(struct i2c_client * client)83 static 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 
94 static const struct i2c_device_id keywest_i2c_id[] = {
95 	{ "keywest", 0 },
96 	{ }
97 };
98 
99 static 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 */
snd_pmac_keywest_cleanup(struct pmac_keywest * i2c)110 void 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 
snd_pmac_tumbler_post_init(void)118 int __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 */
snd_pmac_keywest_init(struct pmac_keywest * i2c)133 int __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 }
148