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 if (!keywest_ctx->client) 63 return -ENODEV; 64 /* 65 * We know the driver is already loaded, so the device should be 66 * already bound. If not it means binding failed, and then there 67 * is no point in keeping the device instantiated. 68 */ 69 if (!keywest_ctx->client->driver) { 70 i2c_unregister_device(keywest_ctx->client); 71 keywest_ctx->client = NULL; 72 return -ENODEV; 73 } 74 75 /* 76 * Let i2c-core delete that device on driver removal. 77 * This is safe because i2c-core holds the core_lock mutex for us. 78 */ 79 list_add_tail(&keywest_ctx->client->detected, 80 &keywest_ctx->client->driver->clients); 81 return 0; 82 } 83 84 static int keywest_remove(struct i2c_client *client) 85 { 86 i2c_set_clientdata(client, NULL); 87 if (! keywest_ctx) 88 return 0; 89 if (client == keywest_ctx->client) 90 keywest_ctx->client = NULL; 91 92 return 0; 93 } 94 95 96 static const struct i2c_device_id keywest_i2c_id[] = { 97 { "keywest", 0 }, 98 { } 99 }; 100 101 static struct i2c_driver keywest_driver = { 102 .driver = { 103 .name = "PMac Keywest Audio", 104 }, 105 .attach_adapter = keywest_attach_adapter, 106 .probe = keywest_probe, 107 .remove = keywest_remove, 108 .id_table = keywest_i2c_id, 109 }; 110 111 /* exported */ 112 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 113 { 114 if (keywest_ctx && keywest_ctx == i2c) { 115 i2c_del_driver(&keywest_driver); 116 keywest_ctx = NULL; 117 } 118 } 119 120 int __devinit snd_pmac_tumbler_post_init(void) 121 { 122 int err; 123 124 if (!keywest_ctx || !keywest_ctx->client) 125 return -ENXIO; 126 127 if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) { 128 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 129 return err; 130 } 131 return 0; 132 } 133 134 /* exported */ 135 int __devinit snd_pmac_keywest_init(struct pmac_keywest *i2c) 136 { 137 int err; 138 139 if (keywest_ctx) 140 return -EBUSY; 141 142 keywest_ctx = i2c; 143 144 if ((err = i2c_add_driver(&keywest_driver))) { 145 snd_printk(KERN_ERR "cannot register keywest i2c driver\n"); 146 return err; 147 } 148 return 0; 149 } 150