Current File : //usr/src/linux-headers-5.15.0-125-generic/include/linux/mux/driver.h
/* 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/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.
*
* 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;
};
/**
* 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 */
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