/* SPDX-License-Identifier: GPL-2.0 */ /* * mux/driver.h - definitions for the multiplexer driver interface * * Copyright (C) 2017 Axentia Technologies AB * * Author: Peter Rosin <peda@axentia.se> */ #ifndef _LINUX_MUX_DRIVER_H #define _LINUX_MUX_DRIVER_H #include <dt-bindings/mux/mux.h> #include <linux/device.h> #include <linux/ktime.h> #include <linux/semaphore.h> struct mux_chip; struct mux_control; /** * struct mux_control_ops - Mux controller operations for a mux chip. * @set: Set the state of the given mux controller. */ struct mux_control_ops { int (*set)(struct mux_control *mux, int state); }; /** * struct mux_control - Represents a mux controller. * @lock: Protects the mux controller state. * @chip: The mux chip that is handling this mux controller. * @cached_state: The current mux controller state, or -1 if none. * @states: The number of mux controller states. * @idle_state: The mux controller state to use when inactive, or one * of MUX_IDLE_AS_IS and MUX_IDLE_DISCONNECT. * @last_change: Timestamp of last change * * Mux drivers may only change @states and @idle_state, and may only do so * between allocation and registration of the mux controller. Specifically, * @cached_state is internal to the mux core and should never be written by * mux drivers. */ struct mux_control { struct semaphore lock; /* protects the state of the mux */ struct mux_chip *chip; int cached_state; unsigned int states; int idle_state; ktime_t last_change; }; /** * struct mux_chip - Represents a chip holding mux controllers. * @controllers: Number of mux controllers handled by the chip. * @mux: Array of mux controllers that are handled. * @dev: Device structure. * @id: Used to identify the device internally. * @ops: Mux controller operations. */ struct mux_chip { unsigned int controllers; struct mux_control *mux; struct device dev; int id; const struct mux_control_ops *ops; }; #define to_mux_chip(x) container_of((x), struct mux_chip, dev) /** * mux_chip_priv() - Get the extra memory reserved by mux_chip_alloc(). * @mux_chip: The mux-chip to get the private memory from. * * Return: Pointer to the private memory reserved by the allocator. */ static inline void *mux_chip_priv(struct mux_chip *mux_chip) { return &mux_chip->mux[mux_chip->controllers]; } struct mux_chip *mux_chip_alloc(struct device *dev, unsigned int controllers, size_t sizeof_priv); int mux_chip_register(struct mux_chip *mux_chip); void mux_chip_unregister(struct mux_chip *mux_chip); void mux_chip_free(struct mux_chip *mux_chip); struct mux_chip *devm_mux_chip_alloc(struct device *dev, unsigned int controllers, size_t sizeof_priv); int devm_mux_chip_register(struct device *dev, struct mux_chip *mux_chip); /** * mux_control_get_index() - Get the index of the given mux controller * @mux: The mux-control to get the index for. * * Return: The index of the mux controller within the mux chip the mux * controller is a part of. */ static inline unsigned int mux_control_get_index(struct mux_control *mux) { return mux - mux->chip->mux; } #endif /* _LINUX_MUX_DRIVER_H */