include/sound/ac97/controller.h

   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 *
  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
  78 snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl)
  79 {
  80 }
  81 #endif
  82
  83 #endif