Usb.h

Go to the documentation of this file.

 
#ifndef _USB_H
#define _USB_H
#include <stdint.h>
#include <stdbool.h>
#include "ReadWriteBits.h"
#ifdef USE_FAKES
#include "Usb_faked.h" // declare fakes
#endif
//---Hardware types: register addresses, pin numbers, bit numbers---
typedef uint8_t volatile * const usb_reg; // i/o reg address
typedef uint8_t const usb_pin; // bit index into i/o reg for an i/o pin
 
// Register address, pin number, and bit definitions depend on compiler:
    // "gcc" uses test/HardwareFake.h
    // "avr-gcc" uses src/Lis-Hardware.h
// ---Registers---
// control lines
extern usb_reg FtCtrl_port;
extern usb_reg FtCtrl_pin;
// bi-directional data lines (driven by both master and slave)
extern usb_reg FtData_pin;
extern usb_reg FtData_ddr;
extern usb_reg FtData_port;
// ---Pins---
// control lines
extern usb_pin FtMiso;
extern usb_pin FtChipSelect;
extern usb_pin FtClock;
// bi-directional data lines (driven by both master and slave)
extern usb_pin FtMiosio0;
// FtMiosio0 is used on its own for flow control.
// FtMiosio[0:7] are used together as a single port for data.
// Write access: *FtData_port
// Read access: *FtData_pin
 
// TODO: change to variables in style of LisConfig and LisConfigs
enum ft_cmd {FtReadCmd=0xC6, FtWriteCmd=0x86};
enum ft_databus_pin_direction {FtIn=0x00, FtOut=0xFF};
enum ft_status {FtError=0, FtOk=1};
enum ft_clock_edge {FtSample=0, FtDrive=1};
 
// ---Private---
inline void _FtClockDatabus(uint8_t direction)
{ // TODO: check compiler eliminates the conditional
    direction ?
        SetBit(FtCtrl_port, FtClock) :  // FtDrive==direction
        ClearBit(FtCtrl_port, FtClock); // FtSample==direction
}
inline void _FtReadDatabus(uint8_t * pbyte)
{
    *pbyte = *FtData_pin;
}
inline void _FtWriteDatabus(uint8_t byte)
{
    *FtData_port = byte;
}
inline void _FtDatabusPinDirection(uint8_t pin_direction)
{
    *FtData_ddr = pin_direction;
}
 
// ---Ft API used internally by Usb---
inline void FtSelectFT221X(void)
{
    ClearBit(FtCtrl_port, FtChipSelect);
}
inline void FtUnselectFT221X(void)
{
    SetBit(FtCtrl_port, FtChipSelect);
}
 
#ifdef USE_FAKES
#define _FtClockDatabus _FtClockDatabus_fake
#endif
inline void FtBusTurnaround(void)
{
    // Clock the FtStatus onto FtMiso
    _FtClockDatabus(FtDrive);  // FtClock rising edge
    _FtClockDatabus(FtSample); // FtClock falling edge
}
#ifdef USE_FAKES
#undef _FtClockDatabus
#endif
 
inline bool FtIsOk(void)
{
    return BitIsClear(FtCtrl_pin, FtMiso);
}
 
#ifdef USE_FAKES
#define _FtClockDatabus _FtClockDatabus_fake
#define _FtReadDatabus _FtReadDatabus_fake
#define _FtDatabusPinDirection _FtDatabusPinDirection_fake
#define _FtWriteDatabus _FtWriteDatabus_fake
#endif
inline void FtRead(uint8_t * pbyte)
{
    // Clock a byte out of the FT221X
    _FtClockDatabus(FtDrive); // FtClock rising edge
    _FtClockDatabus(FtSample); // FtClock falling edge
    // Read the byte into pbyte
    _FtReadDatabus(pbyte);
}
inline void FtWrite(uint8_t byte)
{
    // Set databus for driving data
    _FtClockDatabus(FtDrive); // FtClock rising edge
    // Take control of databus
    _FtDatabusPinDirection(FtOut);
    // Write the byte
    _FtWriteDatabus(byte);
    // Clock the byte into the FT221X
    _FtClockDatabus(FtSample); // FtClock falling edge
    // Relinquish databus to FT221X
    _FtDatabusPinDirection(FtIn);
}
#ifdef USE_FAKES
#undef _FtClockDatabus
#undef _FtReadDatabus
#undef _FtDatabusPinDirection
#undef _FtWriteDatabus
#endif
 
// ---API---
inline bool UsbRxbufferIsEmpty(void)
{
    return BitIsSet(FtCtrl_pin, FtMiso);
}
inline bool UsbTxbufferIsFull(void)
{
    return BitIsSet(FtData_pin, FtMiosio0);
}
 
#ifdef USE_FAKES
#define FtSelectFT221X      FtSelectFT221X_fake
#define FtBusTurnaround     FtBusTurnaround_fake
#define FtIsOk              FtIsOk_fake
#define FtRead              FtRead_fake
#define FtWrite             FtWrite_fake
#define FtUnselectFT221X    FtUnselectFT221X_fake
#endif
inline uint8_t UsbReadByte(uint8_t * pbyte)
{
    uint8_t status = FtError;
    FtSelectFT221X(); // activates FT1248 interface
    FtWrite(FtReadCmd); // Clock FtReadCmd into FT221X
    FtBusTurnaround(); // Relinquish bus to FT221X
    if (FtIsOk())
    {
        status = FtOk; // Buffer is not empty, OK to read a byte
        FtRead(pbyte); // Clock byte out of FT221X UsbRx buffer
    }
    FtUnselectFT221X(); // deactivates FT1248 interface
    return status; // up to caller to check status
}
inline uint8_t UsbWriteByte(uint8_t byte)
{
    uint8_t status = FtError;
    FtSelectFT221X(); // activates FT1248 interface
    FtWrite(FtWriteCmd); // Clock FtWriteCmd into FT221X
    FtBusTurnaround(); // Relinquish bus to FT221X
    if (FtIsOk())
    {
        status = FtOk; // Buffer is not full, OK to write a byte
        FtWrite(byte); // Clock byte into FT221X UsbTx buffer
    }
    FtUnselectFT221X(); // deactivates FT1248 interface
    return status; // up to caller to check status
}
#ifdef USE_FAKES
#undef FtSelectFT221X
#undef FtBusTurnaround
#undef FtIsOk
#undef FtRead
#undef FtWrite
#undef FtUnselectFT221X
#endif
 
#endif // _USB_H