xref: /openbmc/linux/sound/ppc/keywest.c (revision 22246614)
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_attach_adapter(struct i2c_adapter *adapter);
37 static int keywest_detach_client(struct i2c_client *client);
38 
39 struct i2c_driver keywest_driver = {
40 	.driver = {
41 		.name = "PMac Keywest Audio",
42 	},
43 	.attach_adapter = &keywest_attach_adapter,
44 	.detach_client = &keywest_detach_client,
45 };
46 
47 
48 #ifndef i2c_device_name
49 #define i2c_device_name(x)	((x)->name)
50 #endif
51 
52 static int keywest_attach_adapter(struct i2c_adapter *adapter)
53 {
54 	int err;
55 	struct i2c_client *new_client;
56 
57 	if (! keywest_ctx)
58 		return -EINVAL;
59 
60 	if (strncmp(i2c_device_name(adapter), "mac-io", 6))
61 		return 0; /* ignored */
62 
63 	new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
64 	if (! new_client)
65 		return -ENOMEM;
66 
67 	new_client->addr = keywest_ctx->addr;
68 	i2c_set_clientdata(new_client, keywest_ctx);
69 	new_client->adapter = adapter;
70 	new_client->driver = &keywest_driver;
71 	new_client->flags = 0;
72 
73 	strcpy(i2c_device_name(new_client), keywest_ctx->name);
74 	keywest_ctx->client = new_client;
75 
76 	/* Tell the i2c layer a new client has arrived */
77 	if (i2c_attach_client(new_client)) {
78 		snd_printk(KERN_ERR "tumbler: cannot attach i2c client\n");
79 		err = -ENODEV;
80 		goto __err;
81 	}
82 
83 	return 0;
84 
85  __err:
86 	kfree(new_client);
87 	keywest_ctx->client = NULL;
88 	return err;
89 }
90 
91 static int keywest_detach_client(struct i2c_client *client)
92 {
93 	if (! keywest_ctx)
94 		return 0;
95 	if (client == keywest_ctx->client)
96 		keywest_ctx->client = NULL;
97 
98 	i2c_detach_client(client);
99 	kfree(client);
100 	return 0;
101 }
102 
103 /* exported */
104 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
105 {
106 	if (keywest_ctx && keywest_ctx == i2c) {
107 		i2c_del_driver(&keywest_driver);
108 		keywest_ctx = NULL;
109 	}
110 }
111 
112 int __init snd_pmac_tumbler_post_init(void)
113 {
114 	int err;
115 
116 	if (!keywest_ctx || !keywest_ctx->client)
117 		return -ENXIO;
118 
119 	if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
120 		snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
121 		return err;
122 	}
123 	return 0;
124 }
125 
126 /* exported */
127 int __init snd_pmac_keywest_init(struct pmac_keywest *i2c)
128 {
129 	int err;
130 
131 	if (keywest_ctx)
132 		return -EBUSY;
133 
134 	keywest_ctx = i2c;
135 
136 	if ((err = i2c_add_driver(&keywest_driver))) {
137 		snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
138 		return err;
139 	}
140 	return 0;
141 }
142