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/* Copyright 2016 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef __CROS_DEVICE_STATE_H
#define __CROS_DEVICE_STATE_H
enum gpio_signal;
/* Device configuration */
struct device_config {
/* Device name */
const char *name;
/* Current state */
enum device_state state;
/*
* Last known state. That is, the last state value passed to
* device_set_state() which was DEVICE_STATE_OFF or DEVICE_STATE_ON.
* Or DEVICE_STATE_UNKNOWN, if device_set_state() has not been called
* for this device this boot.
*/
enum device_state last_known_state;
/*
* Deferred handler to debounce state transitions. This is NOT used by
* the device_state module; it's just here as a convenience for the
* board.
*/
const struct deferred_data *deferred;
/*
* GPIO used to detect the state. This is NOT used by the device_state
* module; it's just here as a convenience for the board.
*/
enum gpio_signal detect;
};
/*
* board.h must supply an enumerated list of devices, ending in DEVICE_COUNT.
*/
enum device_type;
/*
* board.c must provide this list of device configurations. It must match enum
* device_type, and must be DEVICE_COUNT entries long.
*/
extern struct device_config device_states[];
/**
* Get the current state for the device.
*
* @param device Device to check
* @return The device state (current; NOT last known).
*/
enum device_state device_get_state(enum device_type device);
/**
* Set the device state
*
* Updates the device's last known state if <state> is DEVICE_STATE_ON or
* DEVICE_STATE_OFF, and that's different than the device's last known state.
*
* Note that this only changes the recorded state. It does not notify anything
* of these changes. That must be done by the caller.
*
* @param device Device to update
* @param state New device state
* @return non-zero if this changed the device's last known state.
*/
int device_set_state(enum device_type device, enum device_state state);
/**
* Update the device state based on the device gpios.
*
* The board must implement this. It will be called for each device in the
* context of HOOK_SECOND. If the state has changed, the board is responsible
* for doing any associated reconfiguration and then calling
* device_set_state().
*
* @param device Device to check.
*/
void board_update_device_state(enum device_type device);
#endif /* __CROS_DEVICE_STATE_H */