include/sound/ac97/controller.h

   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