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