LXR linux/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
  16static struct pmac_keywest *keywest_ctx;
  17static bool keywest_probed;
  18
  19static 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 */
  34static 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
  73static 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
  82static 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};
  87MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
  88
  89static 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 */
  99void 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
 107int 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 */
 123int 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