sound/ppc/keywest.c

   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 }