xref: /openbmc/linux/sound/ppc/keywest.c (revision b04b4f78)
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/slab.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  */
33 static struct pmac_keywest *keywest_ctx;
34 
35 
36 static int keywest_probe(struct i2c_client *client,
37 			 const struct i2c_device_id *id)
38 {
39 	i2c_set_clientdata(client, keywest_ctx);
40 	return 0;
41 }
42 
43 /*
44  * This is kind of a hack, best would be to turn powermac to fixed i2c
45  * bus numbers and declare the sound device as part of platform
46  * initialization
47  */
48 static int keywest_attach_adapter(struct i2c_adapter *adapter)
49 {
50 	struct i2c_board_info info;
51 
52 	if (! keywest_ctx)
53 		return -EINVAL;
54 
55 	if (strncmp(adapter->name, "mac-io", 6))
56 		return 0; /* ignored */
57 
58 	memset(&info, 0, sizeof(struct i2c_board_info));
59 	strlcpy(info.type, "keywest", I2C_NAME_SIZE);
60 	info.addr = keywest_ctx->addr;
61 	keywest_ctx->client = i2c_new_device(adapter, &info);
62 
63 	/*
64 	 * Let i2c-core delete that device on driver removal.
65 	 * This is safe because i2c-core holds the core_lock mutex for us.
66 	 */
67 	list_add_tail(&keywest_ctx->client->detected,
68 		      &keywest_ctx->client->driver->clients);
69 	return 0;
70 }
71 
72 static int keywest_remove(struct i2c_client *client)
73 {
74 	i2c_set_clientdata(client, NULL);
75 	if (! keywest_ctx)
76 		return 0;
77 	if (client == keywest_ctx->client)
78 		keywest_ctx->client = NULL;
79 
80 	return 0;
81 }
82 
83 
84 static const struct i2c_device_id keywest_i2c_id[] = {
85 	{ "keywest", 0 },
86 	{ }
87 };
88 
89 struct i2c_driver keywest_driver = {
90 	.driver = {
91 		.name = "PMac Keywest Audio",
92 	},
93 	.attach_adapter = keywest_attach_adapter,
94 	.probe = keywest_probe,
95 	.remove = keywest_remove,
96 	.id_table = keywest_i2c_id,
97 };
98 
99 /* exported */
100 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
101 {
102 	if (keywest_ctx && keywest_ctx == i2c) {
103 		i2c_del_driver(&keywest_driver);
104 		keywest_ctx = NULL;
105 	}
106 }
107 
108 int __init snd_pmac_tumbler_post_init(void)
109 {
110 	int err;
111 
112 	if (!keywest_ctx || !keywest_ctx->client)
113 		return -ENXIO;
114 
115 	if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
116 		snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
117 		return err;
118 	}
119 	return 0;
120 }
121 
122 /* exported */
123 int __init snd_pmac_keywest_init(struct pmac_keywest *i2c)
124 {
125 	int err;
126 
127 	if (keywest_ctx)
128 		return -EBUSY;
129 
130 	keywest_ctx = i2c;
131 
132 	if ((err = i2c_add_driver(&keywest_driver))) {
133 		snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
134 		return err;
135 	}
136 	return 0;
137 }
138