110 lines · c
1/* SPDX-License-Identifier: GPL-2.0 */2/*3 * mux/driver.h - definitions for the multiplexer driver interface4 *5 * Copyright (C) 2017 Axentia Technologies AB6 *7 * Author: Peter Rosin <peda@axentia.se>8 */9 10#ifndef _LINUX_MUX_DRIVER_H11#define _LINUX_MUX_DRIVER_H12 13#include <dt-bindings/mux/mux.h>14#include <linux/device.h>15#include <linux/ktime.h>16#include <linux/semaphore.h>17 18struct mux_chip;19struct mux_control;20 21/**22 * struct mux_control_ops - Mux controller operations for a mux chip.23 * @set: Set the state of the given mux controller.24 */25struct mux_control_ops {26 int (*set)(struct mux_control *mux, int state);27};28 29/**30 * struct mux_control - Represents a mux controller.31 * @lock: Protects the mux controller state.32 * @chip: The mux chip that is handling this mux controller.33 * @cached_state: The current mux controller state, or -1 if none.34 * @states: The number of mux controller states.35 * @idle_state: The mux controller state to use when inactive, or one36 * of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT.37 * @last_change: Timestamp of last change38 *39 * Mux drivers may only change @states and @idle_state, and may only do so40 * between allocation and registration of the mux controller. Specifically,41 * @cached_state is internal to the mux core and should never be written by42 * mux drivers.43 */44struct mux_control {45 struct semaphore lock; /* protects the state of the mux */46 47 struct mux_chip *chip;48 int cached_state;49 50 unsigned int states;51 int idle_state;52 53 ktime_t last_change;54};55 56/**57 * struct mux_chip - Represents a chip holding mux controllers.58 * @controllers: Number of mux controllers handled by the chip.59 * @mux: Array of mux controllers that are handled.60 * @dev: Device structure.61 * @id: Used to identify the device internally.62 * @ops: Mux controller operations.63 */64struct mux_chip {65 unsigned int controllers;66 struct mux_control *mux;67 struct device dev;68 int id;69 70 const struct mux_control_ops *ops;71};72 73#define to_mux_chip(x) container_of((x), struct mux_chip, dev)74 75/**76 * mux_chip_priv() - Get the extra memory reserved by mux_chip_alloc().77 * @mux_chip: The mux-chip to get the private memory from.78 *79 * Return: Pointer to the private memory reserved by the allocator.80 */81static inline void *mux_chip_priv(struct mux_chip *mux_chip)82{83 return &mux_chip->mux[mux_chip->controllers];84}85 86struct mux_chip *mux_chip_alloc(struct device *dev,87 unsigned int controllers, size_t sizeof_priv);88int mux_chip_register(struct mux_chip *mux_chip);89void mux_chip_unregister(struct mux_chip *mux_chip);90void mux_chip_free(struct mux_chip *mux_chip);91 92struct mux_chip *devm_mux_chip_alloc(struct device *dev,93 unsigned int controllers,94 size_t sizeof_priv);95int devm_mux_chip_register(struct device *dev, struct mux_chip *mux_chip);96 97/**98 * mux_control_get_index() - Get the index of the given mux controller99 * @mux: The mux-control to get the index for.100 *101 * Return: The index of the mux controller within the mux chip the mux102 * controller is a part of.103 */104static inline unsigned int mux_control_get_index(struct mux_control *mux)105{106 return mux - mux->chip->mux;107}108 109#endif /* _LINUX_MUX_DRIVER_H */110