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/module.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 static bool keywest_probed; 36 37 static int keywest_probe(struct i2c_client *client, 38 const struct i2c_device_id *id) 39 { 40 keywest_probed = true; 41 /* If instantiated via i2c-powermac, we still need to set the client */ 42 if (!keywest_ctx->client) 43 keywest_ctx->client = client; 44 i2c_set_clientdata(client, keywest_ctx); 45 return 0; 46 } 47 48 /* 49 * This is kind of a hack, best would be to turn powermac to fixed i2c 50 * bus numbers and declare the sound device as part of platform 51 * initialization 52 */ 53 static int keywest_attach_adapter(struct i2c_adapter *adapter) 54 { 55 struct i2c_board_info info; 56 57 if (! keywest_ctx) 58 return -EINVAL; 59 60 if (strncmp(adapter->name, "mac-io", 6)) 61 return -EINVAL; /* ignored */ 62 63 memset(&info, 0, sizeof(struct i2c_board_info)); 64 strlcpy(info.type, "keywest", I2C_NAME_SIZE); 65 info.addr = keywest_ctx->addr; 66 keywest_ctx->client = i2c_new_device(adapter, &info); 67 if (!keywest_ctx->client) 68 return -ENODEV; 69 /* 70 * We know the driver is already loaded, so the device should be 71 * already bound. If not it means binding failed, and then there 72 * is no point in keeping the device instantiated. 73 */ 74 if (!keywest_ctx->client->dev.driver) { 75 i2c_unregister_device(keywest_ctx->client); 76 keywest_ctx->client = NULL; 77 return -ENODEV; 78 } 79 80 /* 81 * Let i2c-core delete that device on driver removal. 82 * This is safe because i2c-core holds the core_lock mutex for us. 83 */ 84 list_add_tail(&keywest_ctx->client->detected, 85 &to_i2c_driver(keywest_ctx->client->dev.driver)->clients); 86 return 0; 87 } 88 89 static int keywest_remove(struct i2c_client *client) 90 { 91 if (! keywest_ctx) 92 return 0; 93 if (client == keywest_ctx->client) 94 keywest_ctx->client = NULL; 95 96 return 0; 97 } 98 99 100 static const struct i2c_device_id keywest_i2c_id[] = { 101 { "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */ 102 { "keywest", 0 }, /* instantiated by us if needed */ 103 { } 104 }; 105 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id); 106 107 static struct i2c_driver keywest_driver = { 108 .driver = { 109 .name = "PMac Keywest Audio", 110 }, 111 .probe = keywest_probe, 112 .remove = keywest_remove, 113 .id_table = keywest_i2c_id, 114 }; 115 116 /* exported */ 117 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 118 { 119 if (keywest_ctx && keywest_ctx == i2c) { 120 i2c_del_driver(&keywest_driver); 121 keywest_ctx = NULL; 122 } 123 } 124 125 int snd_pmac_tumbler_post_init(void) 126 { 127 int err; 128 129 if (!keywest_ctx || !keywest_ctx->client) 130 return -ENXIO; 131 132 if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) { 133 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 134 return err; 135 } 136 return 0; 137 } 138 139 /* exported */ 140 int snd_pmac_keywest_init(struct pmac_keywest *i2c) 141 { 142 struct i2c_adapter *adap; 143 int err, i = 0; 144 145 if (keywest_ctx) 146 return -EBUSY; 147 148 adap = i2c_get_adapter(0); 149 if (!adap) 150 return -EPROBE_DEFER; 151 152 keywest_ctx = i2c; 153 154 if ((err = i2c_add_driver(&keywest_driver))) { 155 snd_printk(KERN_ERR "cannot register keywest i2c driver\n"); 156 i2c_put_adapter(adap); 157 return err; 158 } 159 160 /* There was already a device from i2c-powermac. Great, let's return */ 161 if (keywest_probed) 162 return 0; 163 164 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 165 while (adap) { 166 /* Scan for devices to be bound to */ 167 err = keywest_attach_adapter(adap); 168 if (!err) 169 return 0; 170 i2c_put_adapter(adap); 171 adap = i2c_get_adapter(++i); 172 } 173 174 return -ENODEV; 175 } 176