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/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#pragma once
#include <stdint.h>
#include <atomic>
#include <functional>
#include <memory>
#include <mutex>
#include <optional>
#include <tuple>
#include <utility>
#include "driver/i2c.h"
#include "esp_check.h"
#include "esp_err.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
namespace drivers {
/**
* Wrapper for interfacing with the PCA8575 GPIO expander. Includes basic
* low-level pin setting methods, as well as higher level convenience functions
* for reading, writing, and atomically interacting with the SPI chip select
* pins.
*
* Each method of this class can be called safely from any thread, and all
* updates are guaranteed to be atomic. Any access to chip select related pins
* should be done whilst holding `cs_lock` (preferably via the helper methods).
*/
class IGpios {
public:
virtual ~IGpios() {}
/* Maps each pin of the expander to its number in a `pack`ed uint16. */
enum class Pin {
// Port A
kSdMuxSwitch = 0,
kSdMuxDisable = 1,
kKeyUp = 2,
kKeyDown = 3,
kKeyLock = 4,
kDisplayEnable = 5,
// 6 is unused
kSdPowerEnable = 7,
// Port B
kPhoneDetect = 8,
kAmplifierEnable = 9,
kSdCardDetect = 10,
// 11 through 15 are unused
};
/* Nicer value names for use with kSdMuxSwitch. */
enum SdController {
SD_MUX_ESP = 0,
SD_MUX_SAMD = 1,
};
/*
* Sets a single specific pin to the given value. `true` corresponds to
* HIGH, and `false` corresponds to LOW.
*
* This function will block until the pin has changed level.
*/
virtual auto WriteSync(Pin, bool) -> bool = 0;
/*
* Returns the most recently cached value of the given pin.
*/
virtual auto Get(Pin) const -> bool = 0;
};
class Gpios : public IGpios {
public:
static auto Create() -> Gpios*;
~Gpios();
/*
* Sets a single specific pin to the given value. `true` corresponds to
* HIGH, and `false` corresponds to LOW.
*
* Calls to this method will be buffered in memory until a call to `Write()`
* is made.
*/
auto WriteSync(Pin, bool) -> bool override;
virtual auto WriteBuffered(Pin, bool) -> void;
/**
* Sets the ports on the GPIO expander to the values currently represented
* in `ports`.
*/
auto Flush(void) -> bool;
auto Get(Pin) const -> bool override;
/**
* Reads from the GPIO expander, populating `inputs` with the most recent
* values.
*/
auto Read(void) -> bool;
auto InstallReadPendingISR() -> void;
auto IsReadPending() -> SemaphoreHandle_t { return read_pending_; }
// Not copyable or movable. There should usually only ever be once instance
// of this class, and that instance will likely have a static lifetime.
Gpios(const Gpios&) = delete;
Gpios& operator=(const Gpios&) = delete;
private:
Gpios();
std::atomic<uint16_t> ports_;
std::atomic<uint16_t> inputs_;
SemaphoreHandle_t read_pending_;
};
} // namespace drivers
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