1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * common keywest i2c layer 4 * 5 * Copyright (c) by Takashi Iwai <tiwai@suse.de> 6 */ 7 8 9 #include <linux/init.h> 10 #include <linux/i2c.h> 11 #include <linux/delay.h> 12 #include <linux/module.h> 13 #include <sound/core.h> 14 #include "pmac.h" 15 16 /* 17 * we have to keep a static variable here since i2c attach_adapter 18 * callback cannot pass a private data. 19 */ 20 static struct pmac_keywest *keywest_ctx; 21 22 static bool keywest_probed; 23 24 static int keywest_probe(struct i2c_client *client, 25 const struct i2c_device_id *id) 26 { 27 keywest_probed = true; 28 /* If instantiated via i2c-powermac, we still need to set the client */ 29 if (!keywest_ctx->client) 30 keywest_ctx->client = client; 31 i2c_set_clientdata(client, keywest_ctx); 32 return 0; 33 } 34 35 /* 36 * This is kind of a hack, best would be to turn powermac to fixed i2c 37 * bus numbers and declare the sound device as part of platform 38 * initialization 39 */ 40 static int keywest_attach_adapter(struct i2c_adapter *adapter) 41 { 42 struct i2c_board_info info; 43 struct i2c_client *client; 44 45 if (! keywest_ctx) 46 return -EINVAL; 47 48 if (strncmp(adapter->name, "mac-io", 6)) 49 return -EINVAL; /* ignored */ 50 51 memset(&info, 0, sizeof(struct i2c_board_info)); 52 strlcpy(info.type, "keywest", I2C_NAME_SIZE); 53 info.addr = keywest_ctx->addr; 54 client = i2c_new_client_device(adapter, &info); 55 if (IS_ERR(client)) 56 return PTR_ERR(client); 57 keywest_ctx->client = client; 58 59 /* 60 * We know the driver is already loaded, so the device should be 61 * already bound. If not it means binding failed, and then there 62 * is no point in keeping the device instantiated. 63 */ 64 if (!keywest_ctx->client->dev.driver) { 65 i2c_unregister_device(keywest_ctx->client); 66 keywest_ctx->client = NULL; 67 return -ENODEV; 68 } 69 70 /* 71 * Let i2c-core delete that device on driver removal. 72 * This is safe because i2c-core holds the core_lock mutex for us. 73 */ 74 list_add_tail(&keywest_ctx->client->detected, 75 &to_i2c_driver(keywest_ctx->client->dev.driver)->clients); 76 return 0; 77 } 78 79 static int keywest_remove(struct i2c_client *client) 80 { 81 if (! keywest_ctx) 82 return 0; 83 if (client == keywest_ctx->client) 84 keywest_ctx->client = NULL; 85 86 return 0; 87 } 88 89 90 static const struct i2c_device_id keywest_i2c_id[] = { 91 { "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */ 92 { "keywest", 0 }, /* instantiated by us if needed */ 93 { } 94 }; 95 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id); 96 97 static struct i2c_driver keywest_driver = { 98 .driver = { 99 .name = "PMac Keywest Audio", 100 }, 101 .probe = keywest_probe, 102 .remove = keywest_remove, 103 .id_table = keywest_i2c_id, 104 }; 105 106 /* exported */ 107 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 108 { 109 if (keywest_ctx && keywest_ctx == i2c) { 110 i2c_del_driver(&keywest_driver); 111 keywest_ctx = NULL; 112 } 113 } 114 115 int snd_pmac_tumbler_post_init(void) 116 { 117 int err; 118 119 if (!keywest_ctx || !keywest_ctx->client) 120 return -ENXIO; 121 122 if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) { 123 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 124 return err; 125 } 126 return 0; 127 } 128 129 /* exported */ 130 int snd_pmac_keywest_init(struct pmac_keywest *i2c) 131 { 132 struct i2c_adapter *adap; 133 int err, i = 0; 134 135 if (keywest_ctx) 136 return -EBUSY; 137 138 adap = i2c_get_adapter(0); 139 if (!adap) 140 return -EPROBE_DEFER; 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 i2c_put_adapter(adap); 147 return err; 148 } 149 150 /* There was already a device from i2c-powermac. Great, let's return */ 151 if (keywest_probed) 152 return 0; 153 154 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 155 while (adap) { 156 /* Scan for devices to be bound to */ 157 err = keywest_attach_adapter(adap); 158 if (!err) 159 return 0; 160 i2c_put_adapter(adap); 161 adap = i2c_get_adapter(++i); 162 } 163 164 return -ENODEV; 165 } 166