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 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 */ 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 83 static int keywest_remove(struct i2c_client *client) 84 { 85 i2c_set_clientdata(client, NULL); 86 if (! keywest_ctx) 87 return 0; 88 if (client == keywest_ctx->client) 89 keywest_ctx->client = NULL; 90 91 return 0; 92 } 93 94 95 static const struct i2c_device_id keywest_i2c_id[] = { 96 { "keywest", 0 }, 97 { } 98 }; 99 100 static struct i2c_driver keywest_driver = { 101 .driver = { 102 .name = "PMac Keywest Audio", 103 }, 104 .attach_adapter = keywest_attach_adapter, 105 .probe = keywest_probe, 106 .remove = keywest_remove, 107 .id_table = keywest_i2c_id, 108 }; 109 110 /* exported */ 111 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 112 { 113 if (keywest_ctx && keywest_ctx == i2c) { 114 i2c_del_driver(&keywest_driver); 115 keywest_ctx = NULL; 116 } 117 } 118 119 int __devinit snd_pmac_tumbler_post_init(void) 120 { 121 int err; 122 123 if (!keywest_ctx || !keywest_ctx->client) 124 return -ENXIO; 125 126 if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) { 127 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 128 return err; 129 } 130 return 0; 131 } 132 133 /* exported */ 134 int __devinit snd_pmac_keywest_init(struct pmac_keywest *i2c) 135 { 136 int err; 137 138 if (keywest_ctx) 139 return -EBUSY; 140 141 keywest_ctx = i2c; 142 143 if ((err = i2c_add_driver(&keywest_driver))) { 144 snd_printk(KERN_ERR "cannot register keywest i2c driver\n"); 145 return err; 146 } 147 return 0; 148 } 149