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