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 static struct pmac_keywest *keywest_ctx; 17 static bool keywest_probed; 18 19 static int keywest_probe(struct i2c_client *client, 20 const struct i2c_device_id *id) 21 { 22 keywest_probed = true; 23 /* If instantiated via i2c-powermac, we still need to set the client */ 24 if (!keywest_ctx->client) 25 keywest_ctx->client = client; 26 i2c_set_clientdata(client, keywest_ctx); 27 return 0; 28 } 29 30 /* 31 * This is kind of a hack, best would be to turn powermac to fixed i2c 32 * bus numbers and declare the sound device as part of platform 33 * initialization 34 */ 35 static int keywest_attach_adapter(struct i2c_adapter *adapter) 36 { 37 struct i2c_board_info info; 38 struct i2c_client *client; 39 40 if (! keywest_ctx) 41 return -EINVAL; 42 43 if (strncmp(adapter->name, "mac-io", 6)) 44 return -EINVAL; /* ignored */ 45 46 memset(&info, 0, sizeof(struct i2c_board_info)); 47 strscpy(info.type, "keywest", I2C_NAME_SIZE); 48 info.addr = keywest_ctx->addr; 49 client = i2c_new_client_device(adapter, &info); 50 if (IS_ERR(client)) 51 return PTR_ERR(client); 52 keywest_ctx->client = client; 53 54 /* 55 * We know the driver is already loaded, so the device should be 56 * already bound. If not it means binding failed, and then there 57 * is no point in keeping the device instantiated. 58 */ 59 if (!keywest_ctx->client->dev.driver) { 60 i2c_unregister_device(keywest_ctx->client); 61 keywest_ctx->client = NULL; 62 return -ENODEV; 63 } 64 65 /* 66 * Let i2c-core delete that device on driver removal. 67 * This is safe because i2c-core holds the core_lock mutex for us. 68 */ 69 list_add_tail(&keywest_ctx->client->detected, 70 &to_i2c_driver(keywest_ctx->client->dev.driver)->clients); 71 return 0; 72 } 73 74 static int keywest_remove(struct i2c_client *client) 75 { 76 if (! keywest_ctx) 77 return 0; 78 if (client == keywest_ctx->client) 79 keywest_ctx->client = NULL; 80 81 return 0; 82 } 83 84 85 static const struct i2c_device_id keywest_i2c_id[] = { 86 { "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */ 87 { "keywest", 0 }, /* instantiated by us if needed */ 88 { } 89 }; 90 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id); 91 92 static struct i2c_driver keywest_driver = { 93 .driver = { 94 .name = "PMac Keywest Audio", 95 }, 96 .probe = keywest_probe, 97 .remove = keywest_remove, 98 .id_table = keywest_i2c_id, 99 }; 100 101 /* exported */ 102 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 103 { 104 if (keywest_ctx && keywest_ctx == i2c) { 105 i2c_del_driver(&keywest_driver); 106 keywest_ctx = NULL; 107 } 108 } 109 110 int snd_pmac_tumbler_post_init(void) 111 { 112 int err; 113 114 if (!keywest_ctx || !keywest_ctx->client) 115 return -ENXIO; 116 117 err = keywest_ctx->init_client(keywest_ctx); 118 if (err < 0) { 119 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 120 return err; 121 } 122 return 0; 123 } 124 125 /* exported */ 126 int snd_pmac_keywest_init(struct pmac_keywest *i2c) 127 { 128 struct i2c_adapter *adap; 129 int err, i = 0; 130 131 if (keywest_ctx) 132 return -EBUSY; 133 134 adap = i2c_get_adapter(0); 135 if (!adap) 136 return -EPROBE_DEFER; 137 138 keywest_ctx = i2c; 139 140 err = i2c_add_driver(&keywest_driver); 141 if (err) { 142 snd_printk(KERN_ERR "cannot register keywest i2c driver\n"); 143 i2c_put_adapter(adap); 144 return err; 145 } 146 147 /* There was already a device from i2c-powermac. Great, let's return */ 148 if (keywest_probed) 149 return 0; 150 151 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 152 while (adap) { 153 /* Scan for devices to be bound to */ 154 err = keywest_attach_adapter(adap); 155 if (!err) 156 return 0; 157 i2c_put_adapter(adap); 158 adap = i2c_get_adapter(++i); 159 } 160 161 return -ENODEV; 162 } 163