linux/linux-5.4.31/sound/ppc/keywest.c

163 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* common keywest i2c layer
*
* Copyright (c) by Takashi Iwai <tiwai@suse.de>
*/
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <sound/core.h>
#include "pmac.h"
/*
* we have to keep a static variable here since i2c attach_adapter
* callback cannot pass a private data.
*/
static struct pmac_keywest *keywest_ctx;
static bool keywest_probed;
static int keywest_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
keywest_probed = true;
/* If instantiated via i2c-powermac, we still need to set the client */
if (!keywest_ctx->client)
keywest_ctx->client = client;
i2c_set_clientdata(client, keywest_ctx);
return 0;
}
/*
* This is kind of a hack, best would be to turn powermac to fixed i2c
* bus numbers and declare the sound device as part of platform
* initialization
*/
static int keywest_attach_adapter(struct i2c_adapter *adapter)
{
struct i2c_board_info info;
if (! keywest_ctx)
return -EINVAL;
if (strncmp(adapter->name, "mac-io", 6))
return -EINVAL; /* ignored */
memset(&info, 0, sizeof(struct i2c_board_info));
strlcpy(info.type, "keywest", I2C_NAME_SIZE);
info.addr = keywest_ctx->addr;
keywest_ctx->client = i2c_new_device(adapter, &info);
if (!keywest_ctx->client)
return -ENODEV;
/*
* We know the driver is already loaded, so the device should be
* already bound. If not it means binding failed, and then there
* is no point in keeping the device instantiated.
*/
if (!keywest_ctx->client->dev.driver) {
i2c_unregister_device(keywest_ctx->client);
keywest_ctx->client = NULL;
return -ENODEV;
}
/*
* Let i2c-core delete that device on driver removal.
* This is safe because i2c-core holds the core_lock mutex for us.
*/
list_add_tail(&keywest_ctx->client->detected,
&to_i2c_driver(keywest_ctx->client->dev.driver)->clients);
return 0;
}
static int keywest_remove(struct i2c_client *client)
{
if (! keywest_ctx)
return 0;
if (client == keywest_ctx->client)
keywest_ctx->client = NULL;
return 0;
}
static const struct i2c_device_id keywest_i2c_id[] = {
{ "MAC,tas3004", 0 }, /* instantiated by i2c-powermac */
{ "keywest", 0 }, /* instantiated by us if needed */
{ }
};
MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
static struct i2c_driver keywest_driver = {
.driver = {
.name = "PMac Keywest Audio",
},
.probe = keywest_probe,
.remove = keywest_remove,
.id_table = keywest_i2c_id,
};
/* exported */
void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
{
if (keywest_ctx && keywest_ctx == i2c) {
i2c_del_driver(&keywest_driver);
keywest_ctx = NULL;
}
}
int snd_pmac_tumbler_post_init(void)
{
int err;
if (!keywest_ctx || !keywest_ctx->client)
return -ENXIO;
if ((err = keywest_ctx->init_client(keywest_ctx)) < 0) {
snd_printk(KERN_ERR "tumbler: %i :cannot initialize the MCS\n", err);
return err;
}
return 0;
}
/* exported */
int snd_pmac_keywest_init(struct pmac_keywest *i2c)
{
struct i2c_adapter *adap;
int err, i = 0;
if (keywest_ctx)
return -EBUSY;
adap = i2c_get_adapter(0);
if (!adap)
return -EPROBE_DEFER;
keywest_ctx = i2c;
if ((err = i2c_add_driver(&keywest_driver))) {
snd_printk(KERN_ERR "cannot register keywest i2c driver\n");
i2c_put_adapter(adap);
return err;
}
/* There was already a device from i2c-powermac. Great, let's return */
if (keywest_probed)
return 0;
/* We assume Macs have consecutive I2C bus numbers starting at 0 */
while (adap) {
/* Scan for devices to be bound to */
err = keywest_attach_adapter(adap);
if (!err)
return 0;
i2c_put_adapter(adap);
adap = i2c_get_adapter(++i);
}
return -ENODEV;
}