xref: /openbmc/linux/include/sound/ac97/controller.h (revision faa16bc4)
1 /*
2  *  Copyright (C) 2016 Robert Jarzmik <robert.jarzmik@free.fr>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #ifndef AC97_CONTROLLER_H
9 #define AC97_CONTROLLER_H
10 
11 #include <linux/device.h>
12 #include <linux/list.h>
13 
14 #define AC97_BUS_MAX_CODECS 4
15 #define AC97_SLOTS_AVAILABLE_ALL 0xf
16 
17 struct ac97_controller_ops;
18 
19 /**
20  * struct ac97_controller - The AC97 controller of the AC-Link
21  * @ops:		the AC97 operations.
22  * @controllers:	linked list of all existing controllers.
23  * @adap:		the shell device ac97-%d, ie. ac97 adapter
24  * @nr:			the number of the shell device
25  * @slots_available:	the mask of accessible/scanable codecs.
26  * @parent:		the device providing the AC97 controller.
27  * @codecs:		the 4 possible AC97 codecs (NULL if none found).
28  * @codecs_pdata:	platform_data for each codec (NULL if no pdata).
29  *
30  * This structure is internal to AC97 bus, and should not be used by the
31  * controllers themselves, excepting for using @dev.
32  */
33 struct ac97_controller {
34 	const struct ac97_controller_ops *ops;
35 	struct list_head controllers;
36 	struct device adap;
37 	int nr;
38 	unsigned short slots_available;
39 	struct device *parent;
40 	struct ac97_codec_device *codecs[AC97_BUS_MAX_CODECS];
41 	void *codecs_pdata[AC97_BUS_MAX_CODECS];
42 };
43 
44 /**
45  * struct ac97_controller_ops - The AC97 operations
46  * @reset:	Cold reset of the AC97 AC-Link.
47  * @warm_reset:	Warm reset of the AC97 AC-Link.
48  * @read:	Read of a single AC97 register.
49  *		Returns the register value or a negative error code.
50  * @write:	Write of a single AC97 register.
51  *
52  * These are the basic operation an AC97 controller must provide for an AC97
53  * access functions. Amongst these, all but the last 2 are mandatory.
54  * The slot number is also known as the AC97 codec number, between 0 and 3.
55  */
56 struct ac97_controller_ops {
57 	void (*reset)(struct ac97_controller *adrv);
58 	void (*warm_reset)(struct ac97_controller *adrv);
59 	int (*write)(struct ac97_controller *adrv, int slot,
60 		     unsigned short reg, unsigned short val);
61 	int (*read)(struct ac97_controller *adrv, int slot, unsigned short reg);
62 };
63 
64 #if IS_ENABLED(CONFIG_AC97_BUS_NEW)
65 struct ac97_controller *snd_ac97_controller_register(
66 	const struct ac97_controller_ops *ops, struct device *dev,
67 	unsigned short slots_available, void **codecs_pdata);
68 void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl);
69 #else
70 static inline struct ac97_controller *
71 snd_ac97_controller_register(const struct ac97_controller_ops *ops,
72 			     struct device *dev,
73 			     unsigned short slots_available,
74 			     void **codecs_pdata)
75 {
76 	return ERR_PTR(-ENODEV);
77 }
78 
79 static inline void
80 snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
81 {
82 }
83 #endif
84 
85 #endif
86