Merge pull request #137 from adafruit/genericdevice

add generic device for non-standard transports

Author: ladyada

Adafruit_BusIO_Register.cpp

@@ -88,6 +88,26 @@ Adafruit_BusIO_Register::Adafruit_BusIO_Register(
   _width = width;
 }
 
+/*!
+ * @brief Create a register we access over a GenericDevice
+ * @param genericdevice Generic device to use
+ * @param reg_addr Register address we will read/write
+ * @param width Width of the register in bytes (1-4)
+ * @param byteorder Byte order of register data (LSBFIRST or MSBFIRST)
+ * @param address_width Width of the register address in bytes (1 or 2)
+ */
+Adafruit_BusIO_Register::Adafruit_BusIO_Register(
+    Adafruit_GenericDevice *genericdevice, uint16_t reg_addr, uint8_t width,
+    uint8_t byteorder, uint8_t address_width) {
+  _i2cdevice = nullptr;
+  _spidevice = nullptr;
+  _genericdevice = genericdevice;
+  _addrwidth = address_width;
+  _address = reg_addr;
+  _byteorder = byteorder;
+  _width = width;
+}
+
 /*!
  *    @brief  Write a buffer of data to the register location
  *    @param  buffer Pointer to data to write
@@ -96,17 +116,14 @@ Adafruit_BusIO_Register::Adafruit_BusIO_Register(
  * uncheckable)
  */
 bool Adafruit_BusIO_Register::write(uint8_t *buffer, uint8_t len) {
-
   uint8_t addrbuffer[2] = {(uint8_t)(_address & 0xFF),
                            (uint8_t)(_address >> 8)};
-
   if (_i2cdevice) {
     return _i2cdevice->write(buffer, len, true, addrbuffer, _addrwidth);
   }
   if (_spidevice) {
     if (_spiregtype == ADDRESSED_OPCODE_BIT0_LOW_TO_WRITE) {
       // very special case!
-
       // pass the special opcode address which we set as the high byte of the
       // regaddr
       addrbuffer[0] =
@@ -116,7 +133,6 @@ bool Adafruit_BusIO_Register::write(uint8_t *buffer, uint8_t len) {
       // the address appears to be a byte longer
       return _spidevice->write(buffer, len, addrbuffer, _addrwidth + 1);
     }
-
     if (_spiregtype == ADDRBIT8_HIGH_TOREAD) {
       addrbuffer[0] &= ~0x80;
     }
@@ -129,6 +145,9 @@ bool Adafruit_BusIO_Register::write(uint8_t *buffer, uint8_t len) {
     }
     return _spidevice->write(buffer, len, addrbuffer, _addrwidth);
   }
+  if (_genericdevice) {
+    return _genericdevice->writeRegister(addrbuffer, _addrwidth, buffer, len);
+  }
   return false;
 }
 
@@ -192,23 +211,20 @@ uint32_t Adafruit_BusIO_Register::read(void) {
 uint32_t Adafruit_BusIO_Register::readCached(void) { return _cached; }
 
 /*!
- *    @brief  Read a buffer of data from the register location
- *    @param  buffer Pointer to data to read into
- *    @param  len Number of bytes to read
- *    @return True on successful write (only really useful for I2C as SPI is
- * uncheckable)
- */
+   @brief Read a number of bytes from a register into a buffer
+   @param buffer Buffer to read data into
+   @param len Number of bytes to read into the buffer
+   @return true on successful read, otherwise false
+*/
 bool Adafruit_BusIO_Register::read(uint8_t *buffer, uint8_t len) {
   uint8_t addrbuffer[2] = {(uint8_t)(_address & 0xFF),
                            (uint8_t)(_address >> 8)};
-
   if (_i2cdevice) {
     return _i2cdevice->write_then_read(addrbuffer, _addrwidth, buffer, len);
   }
   if (_spidevice) {
     if (_spiregtype == ADDRESSED_OPCODE_BIT0_LOW_TO_WRITE) {
       // very special case!
-
       // pass the special opcode address which we set as the high byte of the
       // regaddr
       addrbuffer[0] =
@@ -230,6 +246,9 @@ bool Adafruit_BusIO_Register::read(uint8_t *buffer, uint8_t len) {
     }
     return _spidevice->write_then_read(addrbuffer, _addrwidth, buffer, len);
   }
+  if (_genericdevice) {
+    return _genericdevice->readRegister(addrbuffer, _addrwidth, buffer, len);
+  }
   return false;
 }
 

Adafruit_BusIO_Register.h

@@ -6,6 +6,7 @@
 #if !defined(SPI_INTERFACES_COUNT) ||                                          \
     (defined(SPI_INTERFACES_COUNT) && (SPI_INTERFACES_COUNT > 0))
 
+#include <Adafruit_GenericDevice.h>
 #include <Adafruit_I2CDevice.h>
 #include <Adafruit_SPIDevice.h>
 
@@ -57,6 +58,11 @@ class Adafruit_BusIO_Register {
                           uint8_t width = 1, uint8_t byteorder = LSBFIRST,
                           uint8_t address_width = 1);
 
+  Adafruit_BusIO_Register(Adafruit_GenericDevice *genericdevice,
+                          uint16_t reg_addr, uint8_t width = 1,
+                          uint8_t byteorder = LSBFIRST,
+                          uint8_t address_width = 1);
+
   bool read(uint8_t *buffer, uint8_t len);
   bool read(uint8_t *value);
   bool read(uint16_t *value);
@@ -77,6 +83,7 @@ class Adafruit_BusIO_Register {
 private:
   Adafruit_I2CDevice *_i2cdevice;
   Adafruit_SPIDevice *_spidevice;
+  Adafruit_GenericDevice *_genericdevice;
   Adafruit_BusIO_SPIRegType _spiregtype;
   uint16_t _address;
   uint8_t _width, _addrwidth, _byteorder;

Adafruit_GenericDevice.cpp

@@ -0,0 +1,78 @@
+/*
+   Written with help by Claude!
+  https://claude.ai/chat/335f50b1-3dd8-435e-9139-57ec7ca26a3c (at this time
+  chats are not shareable :(
+*/
+
+#include "Adafruit_GenericDevice.h"
+
+/*!  @brief Create a Generic device with the provided read/write functions
+     @param read_func Function pointer for reading raw data
+     @param write_func Function pointer for writing raw data
+     @param readreg_func Function pointer for reading registers (optional)
+     @param writereg_func Function pointer for writing registers (optional) */
+Adafruit_GenericDevice::Adafruit_GenericDevice(
+    busio_genericdevice_read_t read_func,
+    busio_genericdevice_write_t write_func,
+    busio_genericdevice_readreg_t readreg_func,
+    busio_genericdevice_writereg_t writereg_func) {
+  _read_func = read_func;
+  _write_func = write_func;
+  _readreg_func = readreg_func;
+  _writereg_func = writereg_func;
+  _begun = false;
+}
+
+/*! @brief Initializes the device
+    @return true if initialization was successful, otherwise false */
+bool Adafruit_GenericDevice::begin(void) {
+  _begun = true;
+  return true;
+}
+
+/*! @brief Write a buffer of data
+    @param buffer Pointer to buffer of data to write
+    @param len Number of bytes to write
+    @return true if write was successful, otherwise false */
+bool Adafruit_GenericDevice::write(const uint8_t *buffer, size_t len) {
+  if (!_begun)
+    return false;
+  return _write_func(buffer, len);
+}
+
+/*! @brief Read data into a buffer
+    @param buffer Pointer to buffer to read data into
+    @param len Number of bytes to read
+    @return true if read was successful, otherwise false */
+bool Adafruit_GenericDevice::read(uint8_t *buffer, size_t len) {
+  if (!_begun)
+    return false;
+  return _read_func(buffer, len);
+}
+
+/*! @brief Read from a register location
+    @param addr_buf Buffer containing register address
+    @param addrsiz Size of register address in bytes
+    @param buf Buffer to store read data
+    @param bufsiz Size of data to read in bytes
+    @return true if read was successful, otherwise false */
+bool Adafruit_GenericDevice::readRegister(uint8_t *addr_buf, uint8_t addrsiz,
+                                          uint8_t *buf, uint16_t bufsiz) {
+  if (!_begun || !_readreg_func)
+    return false;
+  return _readreg_func(addr_buf, addrsiz, buf, bufsiz);
+}
+
+/*! @brief Write to a register location
+    @param addr_buf Buffer containing register address
+    @param addrsiz Size of register address in bytes
+    @param buf Buffer containing data to write
+    @param bufsiz Size of data to write in bytes
+    @return true if write was successful, otherwise false */
+bool Adafruit_GenericDevice::writeRegister(uint8_t *addr_buf, uint8_t addrsiz,
+                                           const uint8_t *buf,
+                                           uint16_t bufsiz) {
+  if (!_begun || !_writereg_func)
+    return false;
+  return _writereg_func(addr_buf, addrsiz, buf, bufsiz);
+}

Adafruit_GenericDevice.h

@@ -0,0 +1,50 @@
+#ifndef ADAFRUIT_GENERICDEVICE_H
+#define ADAFRUIT_GENERICDEVICE_H
+
+#include <Arduino.h>
+
+typedef bool (*busio_genericdevice_read_t)(uint8_t *buffer, size_t len);
+typedef bool (*busio_genericdevice_write_t)(const uint8_t *buffer, size_t len);
+typedef bool (*busio_genericdevice_readreg_t)(uint8_t *addr_buf,
+                                              uint8_t addrsiz, uint8_t *buf,
+                                              uint16_t bufsiz);
+typedef bool (*busio_genericdevice_writereg_t)(uint8_t *addr_buf,
+                                               uint8_t addrsiz,
+                                               const uint8_t *buf,
+                                               uint16_t bufsiz);
+
+/*!
+ * @brief Class for communicating with a device via generic read/write functions
+ */
+class Adafruit_GenericDevice {
+public:
+  Adafruit_GenericDevice(
+      busio_genericdevice_read_t read_func,
+      busio_genericdevice_write_t write_func,
+      busio_genericdevice_readreg_t readreg_func = nullptr,
+      busio_genericdevice_writereg_t writereg_func = nullptr);
+
+  bool begin(void);
+
+  bool read(uint8_t *buffer, size_t len);
+  bool write(const uint8_t *buffer, size_t len);
+  bool readRegister(uint8_t *addr_buf, uint8_t addrsiz, uint8_t *buf,
+                    uint16_t bufsiz);
+  bool writeRegister(uint8_t *addr_buf, uint8_t addrsiz, const uint8_t *buf,
+                     uint16_t bufsiz);
+
+protected:
+  /*! @brief Function pointer for reading raw data from the device */
+  busio_genericdevice_read_t _read_func;
+  /*! @brief Function pointer for writing raw data to the device */
+  busio_genericdevice_write_t _write_func;
+  /*! @brief Function pointer for reading a 'register' from the device */
+  busio_genericdevice_readreg_t _readreg_func;
+  /*! @brief Function pointer for writing a 'register' to the device */
+  busio_genericdevice_writereg_t _writereg_func;
+
+  bool _begun; ///< whether we have initialized yet (in case the function needs
+               ///< to do something)
+};
+
+#endif // ADAFRUIT_GENERICDEVICE_H

README.md

@@ -1,7 +1,7 @@
 # Adafruit Bus IO Library [![Build Status](https://github.com/adafruit/Adafruit_BusIO/workflows/Arduino%20Library%20CI/badge.svg)](https://github.com/adafruit/Adafruit_BusIO/actions)
 
 
-This is a helper library to abstract away I2C & SPI transactions and registers
+This is a helper library to abstract away I2C, SPI, and 'generic transport' (e.g. UART) transactions and registers
 
 Adafruit invests time and resources providing this open source code, please support Adafruit and open-source hardware by purchasing products from Adafruit!