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/**
* Marlin 3D Printer Firmware
* Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
#pragma once
#include "../core/macros.h"
#include <Wire.h>
// Print debug messages with M111 S2 (Uses 236 bytes of PROGMEM)
//#define DEBUG_TWIBUS
typedef void (*twiReceiveFunc_t)(int bytes);
typedef void (*twiRequestFunc_t)();
/**
* For a light i2c protocol that runs on two boards running Marlin see:
* See https://github.com/MarlinFirmware/Marlin/issues/4776#issuecomment-246262879
*/
#if I2C_SLAVE_ADDRESS > 0
void i2c_on_receive(int bytes); // Demo i2c onReceive handler
void i2c_on_request(); // Demo i2c onRequest handler
#endif
#define TWIBUS_BUFFER_SIZE 32
/**
* TWIBUS class
*
* This class implements a wrapper around the two wire (I2C) bus, allowing
* Marlin to send and request data from any slave device on the bus.
*
* The two main consumers of this class are M260 and M261. M260 provides a way
* to send an I2C packet to a device (no repeated starts) by caching up to 32
* bytes in a buffer and then sending the buffer.
* M261 requests data from a device. The received data is relayed to serial out
* for the host to interpret.
*
* For more information see
* - https://marlinfw.org/docs/gcode/M260.html
* - https://marlinfw.org/docs/gcode/M261.html
*/
class TWIBus {
private:
/**
* @brief Number of bytes on buffer
* @description Number of bytes in the buffer waiting to be flushed to the bus
*/
uint8_t buffer_s = 0;
/**
* @brief Internal buffer
* @details A fixed buffer. TWI commands can be no longer than this.
*/
uint8_t buffer[TWIBUS_BUFFER_SIZE];
public:
/**
* @brief Target device address
* @description The target device address. Persists until changed.
*/
uint8_t addr = 0;
/**
* @brief Class constructor
* @details Initialize the TWI bus and clear the buffer
*/
TWIBus();
/**
* @brief Reset the buffer
* @details Set the buffer to a known-empty state
*/
void reset();
/**
* @brief Send the buffer data to the bus
* @details Flush the buffer to the target address
*/
void send();
/**
* @brief Add one byte to the buffer
* @details Add a byte to the end of the buffer.
* Silently fails if the buffer is full.
*
* @param c a data byte
*/
void addbyte(const char c);
/**
* @brief Add some bytes to the buffer
* @details Add bytes to the end of the buffer.
* Concatenates at the buffer size.
*
* @param src source data address
* @param bytes the number of bytes to add
*/
void addbytes(char src[], uint8_t bytes);
/**
* @brief Add a null-terminated string to the buffer
* @details Add bytes to the end of the buffer up to a nul.
* Concatenates at the buffer size.
*
* @param str source string address
*/
void addstring(char str[]);
/**
* @brief Set the target slave address
* @details The target slave address for sending the full packet
*
* @param adr 7-bit integer address
*/
void address(const uint8_t adr);
/**
* @brief Prefix for echo to serial
* @details Echo a label, length, address, and "data:"
*
* @param bytes the number of bytes to request
*/
static void echoprefix(uint8_t bytes, const char prefix[], uint8_t adr);
/**
* @brief Echo data on the bus to serial
* @details Echo some number of bytes from the bus
* to serial in a parser-friendly format.
*
* @param bytes the number of bytes to request
*/
static void echodata(uint8_t bytes, const char prefix[], uint8_t adr);
/**
* @brief Echo data in the buffer to serial
* @details Echo the entire buffer to serial
* to serial in a parser-friendly format.
*
* @param bytes the number of bytes to request
*/
void echobuffer(const char prefix[], uint8_t adr);
/**
* @brief Request data from the slave device and wait.
* @details Request a number of bytes from a slave device.
* Wait for the data to arrive, and return true
* on success.
*
* @param bytes the number of bytes to request
* @return status of the request: true=success, false=fail
*/
bool request(const uint8_t bytes);
/**
* @brief Capture data from the bus into the buffer.
* @details Capture data after a request has succeeded.
*
* @param bytes the number of bytes to request
* @return the number of bytes captured to the buffer
*/
uint8_t capture(char *dst, const uint8_t bytes);
/**
* @brief Flush the i2c bus.
* @details Get all bytes on the bus and throw them away.
*/
static void flush();
/**
* @brief Request data from the slave device, echo to serial.
* @details Request a number of bytes from a slave device and output
* the returned data to serial in a parser-friendly format.
*
* @param bytes the number of bytes to request
*/
void relay(const uint8_t bytes);
#if I2C_SLAVE_ADDRESS > 0
/**
* @brief Register a slave receive handler
* @details Set a handler to receive data addressed to us
*
* @param handler A function to handle receiving bytes
*/
inline void onReceive(const twiReceiveFunc_t handler) { Wire.onReceive(handler); }
/**
* @brief Register a slave request handler
* @details Set a handler to send data requested from us
*
* @param handler A function to handle receiving bytes
*/
inline void onRequest(const twiRequestFunc_t handler) { Wire.onRequest(handler); }
/**
* @brief Default handler to receive
* @details Receive bytes sent to our slave address
* and simply echo them to serial.
*/
void receive(uint8_t bytes);
/**
* @brief Send a reply to the bus
* @details Send the buffer and clear it.
* If a string is passed, write it into the buffer first.
*/
void reply(char str[]=nullptr);
inline void reply(const char str[]) { reply((char*)str); }
#endif
#if ENABLED(DEBUG_TWIBUS)
/**
* @brief Prints a debug message
* @details Prints a simple debug message "TWIBus::function: value"
*/
static void prefix(const char func[]);
static void debug(const char func[], uint32_t adr);
static void debug(const char func[], char c);
static void debug(const char func[], char adr[]);
static inline void debug(const char func[], uint8_t v) { debug(func, (uint32_t)v); }
#else
static inline void debug(const char[], uint32_t) {}
static inline void debug(const char[], char) {}
static inline void debug(const char[], char[]) {}
static inline void debug(const char[], uint8_t) {}
#endif
};
extern TWIBus i2c;
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