xref: /openbmc/linux/include/sound/ac97/controller.h (revision 1a8f0a3c)
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 
15 struct 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  */
31 struct 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  */
54 struct 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)
63 struct ac97_controller *snd_ac97_controller_register(
64 	const struct ac97_controller_ops *ops, struct device *dev,
65 	unsigned short slots_available, void **codecs_pdata);
66 void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl);
67 #else
68 static inline struct ac97_controller *
snd_ac97_controller_register(const struct ac97_controller_ops * ops,struct device * dev,unsigned short slots_available,void ** codecs_pdata)69 snd_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 
77 static inline void
snd_ac97_controller_unregister(struct ac97_controller * ac97_ctrl)78 snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
79 {
80 }
81 #endif
82 
83 #endif
84