LXR linux/include/linux/mux/driver.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * mux/driver.h - definitions for the multiplexer driver interface
   4 *
   5 * Copyright (C) 2017 Axentia Technologies AB
   6 *
   7 * Author: Peter Rosin <peda@axentia.se>
   8 */
   9
  10#ifndef _LINUX_MUX_DRIVER_H
  11#define _LINUX_MUX_DRIVER_H
  12
  13#include <dt-bindings/mux/mux.h>
  14#include <linux/device.h>
  15#include <linux/semaphore.h>
  16
  17struct mux_chip;
  18struct mux_control;
  19
  20/**
  21 * struct mux_control_ops -     Mux controller operations for a mux chip.
  22 * @set:                        Set the state of the given mux controller.
  23 */
  24struct mux_control_ops {
  25        int (*set)(struct mux_control *mux, int state);
  26};
  27
  28/**
  29 * struct mux_control - Represents a mux controller.
  30 * @lock:               Protects the mux controller state.
  31 * @chip:               The mux chip that is handling this mux controller.
  32 * @cached_state:       The current mux controller state, or -1 if none.
  33 * @states:             The number of mux controller states.
  34 * @idle_state:         The mux controller state to use when inactive, or one
  35 *                      of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT.
  36 *
  37 * Mux drivers may only change @states and @idle_state, and may only do so
  38 * between allocation and registration of the mux controller. Specifically,
  39 * @cached_state is internal to the mux core and should never be written by
  40 * mux drivers.
  41 */
  42struct mux_control {
  43        struct semaphore lock; /* protects the state of the mux */
  44
  45        struct mux_chip *chip;
  46        int cached_state;
  47
  48        unsigned int states;
  49        int idle_state;
  50};
  51
  52/**
  53 * struct mux_chip -    Represents a chip holding mux controllers.
  54 * @controllers:        Number of mux controllers handled by the chip.
  55 * @mux:                Array of mux controllers that are handled.
  56 * @dev:                Device structure.
  57 * @id:                 Used to identify the device internally.
  58 * @ops:                Mux controller operations.
  59 */
  60struct mux_chip {
  61        unsigned int controllers;
  62        struct mux_control *mux;
  63        struct device dev;
  64        int id;
  65
  66        const struct mux_control_ops *ops;
  67};
  68
  69#define to_mux_chip(x) container_of((x), struct mux_chip, dev)
  70
  71/**
  72 * mux_chip_priv() - Get the extra memory reserved by mux_chip_alloc().
  73 * @mux_chip: The mux-chip to get the private memory from.
  74 *
  75 * Return: Pointer to the private memory reserved by the allocator.
  76 */
  77static inline void *mux_chip_priv(struct mux_chip *mux_chip)
  78{
  79        return &mux_chip->mux[mux_chip->controllers];
  80}
  81
  82struct mux_chip *mux_chip_alloc(struct device *dev,
  83                                unsigned int controllers, size_t sizeof_priv);
  84int mux_chip_register(struct mux_chip *mux_chip);
  85void mux_chip_unregister(struct mux_chip *mux_chip);
  86void mux_chip_free(struct mux_chip *mux_chip);
  87
  88struct mux_chip *devm_mux_chip_alloc(struct device *dev,
  89                                     unsigned int controllers,
  90                                     size_t sizeof_priv);
  91int devm_mux_chip_register(struct device *dev, struct mux_chip *mux_chip);
  92
  93/**
  94 * mux_control_get_index() - Get the index of the given mux controller
  95 * @mux: The mux-control to get the index for.
  96 *
  97 * Return: The index of the mux controller within the mux chip the mux
  98 * controller is a part of.
  99 */
 100static inline unsigned int mux_control_get_index(struct mux_control *mux)
 101{
 102        return mux - mux->chip->mux;
 103}
 104
 105#endif /* _LINUX_MUX_DRIVER_H */
 106