LXR linux/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
  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