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	return 0;
 65}
 66
 67static void keywest_remove(struct i2c_client *client)
 68{
 69	if (! keywest_ctx)
 70		return;
 71	if (client == keywest_ctx->client)
 72		keywest_ctx->client = NULL;
 73}
 74
 75
 76static const struct i2c_device_id keywest_i2c_id[] = {
 77	{ "MAC,tas3004" },	/* instantiated by i2c-powermac */
 78	{ "keywest" },		/* instantiated by us if needed */
 79	{ }
 80};
 81MODULE_DEVICE_TABLE(i2c, keywest_i2c_id);
 82
 83static struct i2c_driver keywest_driver = {
 84	.driver = {
 85		.name = "PMac Keywest Audio",
 86	},
 87	.probe = keywest_probe,
 88	.remove = keywest_remove,
 89	.id_table = keywest_i2c_id,
 90};
 91
 92/* exported */
 93void snd_pmac_keywest_cleanup(struct pmac_keywest *i2c)
 94{
 95	if (keywest_ctx && keywest_ctx == i2c) {
 96		i2c_unregister_device(keywest_ctx->client);
 97		i2c_del_driver(&keywest_driver);
 98		keywest_ctx = NULL;
 99	}
100}
101
102int snd_pmac_tumbler_post_init(void)
103{
104	int err;
105	
106	if (!keywest_ctx || !keywest_ctx->client)
107		return -ENXIO;
108
109	err = keywest_ctx->init_client(keywest_ctx);
110	if (err < 0) {
111		dev_err(&keywest_ctx->client->dev,
112			"tumbler: %i :cannot initialize the MCS\n", err);
113		return err;
114	}
115	return 0;
116}
117
118/* exported */
119int snd_pmac_keywest_init(struct pmac_keywest *i2c)
120{
121	struct i2c_adapter *adap;
122	int err, i = 0;
123
124	if (keywest_ctx)
125		return -EBUSY;
126
127	adap = i2c_get_adapter(0);
128	if (!adap)
129		return -EPROBE_DEFER;
130
131	keywest_ctx = i2c;
132
133	err = i2c_add_driver(&keywest_driver);
134	if (err) {
135		dev_err(&i2c->client->dev, "cannot register keywest i2c driver\n");
136		i2c_put_adapter(adap);
137		return err;
138	}
139
140	/* There was already a device from i2c-powermac. Great, let's return */
141	if (keywest_probed)
142		return 0;
143
144	/* We assume Macs have consecutive I2C bus numbers starting at 0 */
145	while (adap) {
146		/* Scan for devices to be bound to */
147		err = keywest_attach_adapter(adap);
148		if (!err)
149			return 0;
150		i2c_put_adapter(adap);
151		adap = i2c_get_adapter(++i);
152	}
153
154	return -ENODEV;
155}