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 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         if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
 118                 snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 119                 return err;
 120         }
 121         return 0;
 122 }
 123
 124 /* exported */
 125 int snd_pmac_keywest_init(struct pmac_keywest *i2c)
 126 {
 127         struct i2c_adapter *adap;
 128         int err, i = 0;
 129
 130         if (keywest_ctx)
 131                 return -EBUSY;
 132
 133         adap = i2c_get_adapter(0);
 134         if (!adap)
 135                 return -EPROBE_DEFER;
 136
 137         keywest_ctx = i2c;
 138
 139         if ((err = i2c_add_driver(&keywest_driver))) {
 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 }