1/* SPDX-License-Identifier: GPL-2.0
2 *
3 * Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr>
4 */
5
6#ifndef AC97_CONTROLLER_H
7#define AC97_CONTROLLER_H
8
9#include <linux/device.h>
10#include <linux/list.h>
11
12#define AC97_BUS_MAX_CODECS 4
13#define AC97_SLOTS_AVAILABLE_ALL 0xf
14
15struct ac97_controller_ops;
16
17/**
18 * struct ac97_controller - The AC97 controller of the AC-Link
19 * @ops:		the AC97 operations.
20 * @controllers:	linked list of all existing controllers.
21 * @adap:		the shell device ac97-%d, ie. ac97 adapter
22 * @nr:			the number of the shell device
23 * @slots_available:	the mask of accessible/scanable codecs.
24 * @parent:		the device providing the AC97 controller.
25 * @codecs:		the 4 possible AC97 codecs (NULL if none found).
26 * @codecs_pdata:	platform_data for each codec (NULL if no pdata).
27 *
28 * This structure is internal to AC97 bus, and should not be used by the
29 * controllers themselves, excepting for using @dev.
30 */
31struct ac97_controller {
32	const struct ac97_controller_ops *ops;
33	struct list_head controllers;
34	struct device adap;
35	int nr;
36	unsigned short slots_available;
37	struct device *parent;
38	struct ac97_codec_device *codecs[AC97_BUS_MAX_CODECS];
39	void *codecs_pdata[AC97_BUS_MAX_CODECS];
40};
41
42/**
43 * struct ac97_controller_ops - The AC97 operations
44 * @reset:	Cold reset of the AC97 AC-Link.
45 * @warm_reset:	Warm reset of the AC97 AC-Link.
46 * @read:	Read of a single AC97 register.
47 *		Returns the register value or a negative error code.
48 * @write:	Write of a single AC97 register.
49 *
50 * These are the basic operation an AC97 controller must provide for an AC97
51 * access functions. Amongst these, all but the last 2 are mandatory.
52 * The slot number is also known as the AC97 codec number, between 0 and 3.
53 */
54struct ac97_controller_ops {
55	void (*reset)(struct ac97_controller *adrv);
56	void (*warm_reset)(struct ac97_controller *adrv);
57	int (*write)(struct ac97_controller *adrv, int slot,
58		     unsigned short reg, unsigned short val);
59	int (*read)(struct ac97_controller *adrv, int slot, unsigned short reg);
60};
61
62#if IS_ENABLED(CONFIG_AC97_BUS_NEW)
63struct ac97_controller *snd_ac97_controller_register(
64	const struct ac97_controller_ops *ops, struct device *dev,
65	unsigned short slots_available, void **codecs_pdata);
66void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl);
67#else
68static inline struct ac97_controller *
69snd_ac97_controller_register(const struct ac97_controller_ops *ops,
70			     struct device *dev,
71			     unsigned short slots_available,
72			     void **codecs_pdata)
73{
74	return ERR_PTR(-ENODEV);
75}
76
77static inline void
78snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
79{
80}
81#endif
82
83#endif
84