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