OpenRTX/lib/miosix-kernel/miosix/arch/common/drivers/serial_lpc2000.h

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6.9 KiB
C++

/***************************************************************************
* Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013, 2014 *
* by Terraneo Federico *
* *
* 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 2 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. *
* *
* As a special exception, if other files instantiate templates or use *
* macros or inline functions from this file, or you compile this file *
* and link it with other works to produce a work based on this file, *
* this file does not by itself cause the resulting work to be covered *
* by the GNU General Public License. However the source code for this *
* file must still be made available in accordance with the GNU General *
* Public License. This exception does not invalidate any other reasons *
* why a work based on this file might be covered by the GNU General *
* Public License. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef SERIAL_LPC2000_H
#define SERIAL_LPC2000_H
#include "filesystem/console/console_device.h"
#include "kernel/sync.h"
#include "kernel/queue.h"
#include "interfaces/delays.h"
namespace miosix {
/**
* Serial port class for LPC2000 microcontrollers.
*
* Classes of this type are reference counted, must be allocated on the heap
* and managed through intrusive_ref_ptr<FileBase>
*/
class LPC2000Serial : public Device
{
public:
/**
* Constructor, initializes the serial port.
* Calls errorHandler(UNEXPECTED) if id is not in the correct range, or when
* attempting to construct multiple objects with the same id. That is,
* it is possible to instantiate only one instance of this class for each
* hardware USART.
* \param id 0=USART0, 1=USART1
* \param baudrate serial port baudrate.
*/
LPC2000Serial(int id, int baudrate);
/**
* Read a block of data
* \param buffer buffer where read data will be stored
* \param size buffer size
* \param where where to read from
* \return number of bytes read or a negative number on failure
*/
ssize_t readBlock(void *buffer, size_t size, off_t where);
/**
* Write a block of data
* \param buffer buffer where take data to write
* \param size buffer size
* \param where where to write to
* \return number of bytes written or a negative number on failure
*/
ssize_t writeBlock(const void *buffer, size_t size, off_t where);
/**
* Write a string.
* An extension to the Device interface that adds a new member function,
* which is used by the kernel on console devices to write debug information
* before the kernel is started or in case of serious errors, right before
* rebooting.
* Can ONLY be called when the kernel is not yet started, paused or within
* an interrupt. This default implementation ignores writes.
* \param str the string to write. The string must be NUL terminated.
*/
void IRQwrite(const char *str);
/**
* Performs device-specific operations
* \param cmd specifies the operation to perform
* \param arg optional argument that some operation require
* \return the exact return value depends on CMD, -1 is returned on error
*/
int ioctl(int cmd, void *arg);
/**
* \internal the serial port interrupts call this member function.
* Never call this from user code.
*/
void IRQhandleInterrupt();
/**
* Destructor
*/
~LPC2000Serial();
private:
/**
* Wait until all characters have been written to the serial port
*/
void waitSerialTxFifoEmpty()
{
while((serial->LSR & (1<<6))==0) ;
//This delay has been added to fix a quirk on the Miosix board. When
//writing a message to the console and rebooting, if the reboot happens
//too fast with respect to the last character sent out of the serial
//port, the FT232 gets confused and the last charcters are lost,
//probably from the FT232 buffer. Using delayMs() to be callable from IRQ
delayMs(2);
}
/**
* The registers of the USART in struct form, to make a generic driver
*/
struct Usart16550
{
//Offset 0x00
union {
volatile unsigned char RBR;
volatile unsigned char THR;
volatile unsigned char DLL;
};
char padding0[3];
//Offset 0x04
union {
volatile unsigned char IER;
volatile unsigned char DLM;
};
char padding1[3];
//Offset 0x08
union {
volatile unsigned char IIR;
volatile unsigned char FCR;
};
char padding2[3];
//Offset 0x0c
volatile unsigned char LCR;
char padding3[3];
//Offset 0x10
volatile unsigned char MCR; //Only USART1 has this
char padding4[3];
//Offset 0x14
volatile unsigned char LSR;
char padding5[7];
//Offset 0x1c
volatile unsigned char SCR;
char padding6[19];
//Offset 0x30
volatile unsigned char TER;
};
//Configure the software queue here
static const int swTxQueue=32;///< Size of tx software queue
//The hardware queues cannot be modified, since their length is hardware-specific
static const int hwTxQueueLen=16;
static const int hwRxQueueLen=8;
FastMutex txMutex;///< Mutex used to guard the tx queue
FastMutex rxMutex;///< Mutex used to guard the rx queue
Queue<char,swTxQueue> txQueue;///< Tx software queue
DynUnsyncQueue<char> rxQueue;///< Rx software queue
Thread *rxWaiting; ///< Thread waiting on rx queue
bool idle; ///< Receiver idle
Usart16550 *serial; ///< Serial port registers
};
} //namespace miosix
#endif //SERIAL_LPC2000_H