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                         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 */
  35static 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
  74static 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
  85static 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};
  90MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
  91
  92static 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 */
 102void 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
 110int snd_pmac_tumbler_post_init(void)
 111{
 112        int err;
 113        
 114        if (!keywest_ctx || !keywest_ctx->client)
 115                return -ENXIO;
 116
 117        err = keywest_ctx->init_client(keywest_ctx);
 118        if (err < 0) {
 119                snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
 120                return err;
 121        }
 122        return 0;
 123}
 124
 125/* exported */
 126int snd_pmac_keywest_init(struct pmac_keywest *i2c)
 127{
 128        struct i2c_adapter *adap;
 129        int err, i = 0;
 130
 131        if (keywest_ctx)
 132                return -EBUSY;
 133
 134        adap = i2c_get_adapter(0);
 135        if (!adap)
 136                return -EPROBE_DEFER;
 137
 138        keywest_ctx = i2c;
 139
 140        err = i2c_add_driver(&keywest_driver);
 141        if (err) {
 142                snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
 143                i2c_put_adapter(adap);
 144                return err;
 145        }
 146
 147        /* There was already a device from i2c-powermac. Great, let's return */
 148        if (keywest_probed)
 149                return 0;
 150
 151        /* We assume Macs have consecutive I2C bus numbers starting at 0 */
 152        while (adap) {
 153                /* Scan for devices to be bound to */
 154                err = keywest_attach_adapter(adap);
 155                if (!err)
 156                        return 0;
 157                i2c_put_adapter(adap);
 158                adap = i2c_get_adapter(++i);
 159        }
 160
 161        return -ENODEV;
 162}
 163