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 44 if (! keywest_ctx) 45 return -EINVAL; 46 47 if (strncmp(adapter->name, "mac-io", 6)) 48 return -EINVAL; /* ignored */ 49 50 memset(&info, 0, sizeof(struct i2c_board_info)); 51 strlcpy(info.type, "keywest", I2C_NAME_SIZE); 52 info.addr = keywest_ctx->addr; 53 keywest_ctx->client = i2c_new_device(adapter, &info); 54 if (!keywest_ctx->client) 55 return -ENODEV; 56 /* 57 * We know the driver is already loaded, so the device should be 58 * already bound. If not it means binding failed, and then there 59 * is no point in keeping the device instantiated. 60 */ 61 if (!keywest_ctx->client->dev.driver) { 62 i2c_unregister_device(keywest_ctx->client); 63 keywest_ctx->client = NULL; 64 return -ENODEV; 65 } 66 67 /* 68 * Let i2c-core delete that device on driver removal. 69 * This is safe because i2c-core holds the core_lock mutex for us. 70 */ 71 list_add_tail(&keywest_ctx->client->detected, 72 &to_i2c_driver(keywest_ctx->client->dev.driver)->clients); 73 return 0; 74 } 75 76 static int keywest_remove(struct i2c_client *client) 77 { 78 if (! keywest_ctx) 79 return 0; 80 if (client == keywest_ctx->client) 81 keywest_ctx->client = NULL; 82 83 return 0; 84 } 85 86 87 static const struct i2c_device_id keywest_i2c_id[] = { 88 { "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */ 89 { "keywest", 0 }, /* instantiated by us if needed */ 90 { } 91 }; 92 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id); 93 94 static struct i2c_driver keywest_driver = { 95 .driver = { 96 .name = "PMac Keywest Audio", 97 }, 98 .probe = keywest_probe, 99 .remove = keywest_remove, 100 .id_table = keywest_i2c_id, 101 }; 102 103 /* exported */ 104 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 105 { 106 if (keywest_ctx && keywest_ctx == i2c) { 107 i2c_del_driver(&keywest_driver); 108 keywest_ctx = NULL; 109 } 110 } 111 112 int snd_pmac_tumbler_post_init(void) 113 { 114 int err; 115 116 if (!keywest_ctx || !keywest_ctx->client) 117 return -ENXIO; 118 119 if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) { 120 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 121 return err; 122 } 123 return 0; 124 } 125 126 /* exported */ 127 int snd_pmac_keywest_init(struct pmac_keywest *i2c) 128 { 129 struct i2c_adapter *adap; 130 int err, i = 0; 131 132 if (keywest_ctx) 133 return -EBUSY; 134 135 adap = i2c_get_adapter(0); 136 if (!adap) 137 return -EPROBE_DEFER; 138 139 keywest_ctx = i2c; 140 141 if ((err = i2c_add_driver(&keywest_driver))) { 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