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 void keywest_remove(struct i2c_client *client) 75 { 76 if (! keywest_ctx) 77 return; 78 if (client == keywest_ctx->client) 79 keywest_ctx->client = NULL; 80 } 81 82 83 static const struct i2c_device_id keywest_i2c_id[] = { 84 { "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */ 85 { "keywest", 0 }, /* instantiated by us if needed */ 86 { } 87 }; 88 MODULE_DEVICE_TABLE(i2c, keywest_i2c_id); 89 90 static struct i2c_driver keywest_driver = { 91 .driver = { 92 .name = "PMac Keywest Audio", 93 }, 94 .probe = keywest_probe, 95 .remove = keywest_remove, 96 .id_table = keywest_i2c_id, 97 }; 98 99 /* exported */ 100 void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c) 101 { 102 if (keywest_ctx && keywest_ctx == i2c) { 103 i2c_del_driver(&keywest_driver); 104 keywest_ctx = NULL; 105 } 106 } 107 108 int snd_pmac_tumbler_post_init(void) 109 { 110 int err; 111 112 if (!keywest_ctx || !keywest_ctx->client) 113 return -ENXIO; 114 115 err = keywest_ctx->init_client(keywest_ctx); 116 if (err < 0) { 117 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err); 118 return err; 119 } 120 return 0; 121 } 122 123 /* exported */ 124 int snd_pmac_keywest_init(struct pmac_keywest *i2c) 125 { 126 struct i2c_adapter *adap; 127 int err, i = 0; 128 129 if (keywest_ctx) 130 return -EBUSY; 131 132 adap = i2c_get_adapter(0); 133 if (!adap) 134 return -EPROBE_DEFER; 135 136 keywest_ctx = i2c; 137 138 err = i2c_add_driver(&keywest_driver); 139 if (err) { 140 snd_printk(KERN_ERR "cannot register keywest i2c driver\n"); 141 i2c_put_adapter(adap); 142 return err; 143 } 144 145 /* There was already a device from i2c-powermac. Great, let's return */ 146 if (keywest_probed) 147 return 0; 148 149 /* We assume Macs have consecutive I2C bus numbers starting at 0 */ 150 while (adap) { 151 /* Scan for devices to be bound to */ 152 err = keywest_attach_adapter(adap); 153 if (!err) 154 return 0; 155 i2c_put_adapter(adap); 156 adap = i2c_get_adapter(++i); 157 } 158 159 return -ENODEV; 160 } 161