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17b5b576ff
Hardware may require some time for the muxed analog signals to settle after the muxing is changed. Allow users of the mux subsystem to specify this delay with the new mux_control_select_delay() function (and the _try equivalent). Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Reviewed-by: Lars-Peter Clausen <lars@metafoo.de> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Acked-by: Peter Rosin <peda@axentia.se> Link: https://lore.kernel.org/r/20211007134641.13417-2-vincent.whitchurch@axis.com Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
109 lines
3.1 KiB
C
109 lines
3.1 KiB
C
/* 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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