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/*--------------------------------------------------------------------
 * TITLE: Plasma Uart Driver
 * AUTHOR: Steve Rhoads (rhoadss@yahoo.com)
 * DATE CREATED: 12/31/05
 * FILENAME: uart.c
 * PROJECT: Plasma CPU core
 * COPYRIGHT: Software placed into the public domain by the author.
 *    Software 'as is' without warranty.  Author liable for nothing.
 * DESCRIPTION:
 *    Plasma Uart Driver
 *--------------------------------------------------------------------*/
#define NO_ELLIPSIS2
#include "plasma.h"
#include "rtos.h"
 
#define BUFFER_WRITE_SIZE 128
#define BUFFER_READ_SIZE 128
#define BUFFER_PRINTF_SIZE 128
#undef UartPrintf
 
typedef struct Buffer_s {
   uint8 *data;
   int size;
   volatile int read, write;
   volatile int pendingRead, pendingWrite;
   OS_Semaphore_t *semaphoreRead, *semaphoreWrite;
} Buffer_t;
 
static Buffer_t *WriteBuffer, *ReadBuffer;
static OS_Semaphore_t *SemaphoreUart;
static char PrintfString[BUFFER_PRINTF_SIZE];  //Used in UartPrintf
 
 
/******************************************/
Buffer_t *BufferCreate(int size)
{
   Buffer_t *buffer;
   buffer = (Buffer_t*)OS_HeapMalloc(NULL, sizeof(Buffer_t) + size);
   if(buffer == NULL)
      return NULL;
   buffer->data = (uint8*)(buffer + 1);
   buffer->read = 0;
   buffer->write = 0;
   buffer->size = size;
   buffer->pendingRead = 0;
   buffer->pendingWrite = 0;
   buffer->semaphoreRead = OS_SemaphoreCreate("BufferRead", 0);
   buffer->semaphoreWrite = OS_SemaphoreCreate("BufferWrite", 0);
   return buffer;
}
 
 
void BufferWrite(Buffer_t *Buffer, int Value, int Pend)
{
   int writeNext;
 
   writeNext = Buffer->write + 1;
   if(writeNext >= Buffer->size)
      writeNext = 0;
 
   //Check if room for value
   if(writeNext == Buffer->read)
   {
      if(Pend == 0)
         return;
      ++Buffer->pendingWrite;
      OS_SemaphorePend(Buffer->semaphoreWrite, OS_WAIT_FOREVER);
   }
 
   Buffer->data[Buffer->write] = (uint8)Value;
   Buffer->write = writeNext;
   if(Buffer->pendingRead)
   {
      --Buffer->pendingRead;
      OS_SemaphorePost(Buffer->semaphoreRead);
   }
}
 
 
int BufferRead(Buffer_t *Buffer, int Pend)
{
   int value;
 
   //Check if empty buffer
   if(Buffer->read == Buffer->write)
   {
      if(Pend == 0)
         return 0;
      ++Buffer->pendingRead;
      OS_SemaphorePend(Buffer->semaphoreRead, OS_WAIT_FOREVER);
   }
 
   value = Buffer->data[Buffer->read];
   if(++Buffer->read >= Buffer->size)
      Buffer->read = 0;
   if(Buffer->pendingWrite)
   {
      --Buffer->pendingWrite;
      OS_SemaphorePost(Buffer->semaphoreWrite);
   }
   return value;
}
 
 
/******************************************/
static void UartInterrupt(void *Arg)
{
   uint32 status, value;
   (void)Arg;
 
   status = OS_InterruptStatus();
   if(status & IRQ_UART_READ_AVAILABLE)
   {
      value = MemoryRead(UART_READ);
      BufferWrite(ReadBuffer, value, 0);
   }
   if(status & IRQ_UART_WRITE_AVAILABLE)
   {
      if(WriteBuffer->read != WriteBuffer->write)
      {
         value = BufferRead(WriteBuffer, 0);
         MemoryWrite(UART_WRITE, value);
      }
      else
      {
         OS_InterruptMaskClear(IRQ_UART_WRITE_AVAILABLE);
      }
   }
}
 
 
void UartInit(void)
{
   uint32 mask;
 
   SemaphoreUart = OS_SemaphoreCreate("Uart", 1);
   WriteBuffer = BufferCreate(BUFFER_WRITE_SIZE);
   ReadBuffer = BufferCreate(BUFFER_READ_SIZE);
 
   mask = IRQ_UART_READ_AVAILABLE | IRQ_UART_WRITE_AVAILABLE;
   OS_InterruptRegister(mask, UartInterrupt);
   OS_InterruptMaskSet(IRQ_UART_READ_AVAILABLE);
}
 
 
void UartWrite(int C)
{
   BufferWrite(WriteBuffer, C, 1);
   OS_InterruptMaskSet(IRQ_UART_WRITE_AVAILABLE);
}
 
 
uint8 UartRead(void)
{
   return (uint8)BufferRead(ReadBuffer, 1);
}
 
 
void UartWriteData(uint8 *Data, int Length)
{
   OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   while(Length--)
      UartWrite(*Data++);
   OS_SemaphorePost(SemaphoreUart);
}
 
 
void UartReadData(uint8 *Data, int Length)
{
   OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   while(Length--)
      *Data++ = UartRead();
   OS_SemaphorePost(SemaphoreUart);
}
 
 
void UartPrintf(const char *format,
                int arg0, int arg1, int arg2, int arg3,
                int arg4, int arg5, int arg6, int arg7)
{
   uint8 *ptr;
   OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   sprintf(PrintfString, format, arg0, arg1, arg2, arg3,
           arg4, arg5, arg6, arg7);
   ptr = (uint8*)PrintfString;
   while(*ptr)
   {
      if(*ptr == '\n')
         UartWrite('\r');
      UartWrite(*ptr++);
   }
   OS_SemaphorePost(SemaphoreUart);
}
 
 
void UartPrintfPoll(const char *format,
                    int arg0, int arg1, int arg2, int arg3,
                    int arg4, int arg5, int arg6, int arg7)
{
   uint8 *ptr;
 
   if(SemaphoreUart)
      OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   sprintf(PrintfString, format, arg0, arg1, arg2, arg3,
           arg4, arg5, arg6, arg7);
   ptr = (uint8*)PrintfString;
   while(*ptr)
   {
      while((MemoryRead(IRQ_STATUS) & IRQ_UART_WRITE_AVAILABLE) == 0)
         ;
      MemoryWrite(UART_WRITE, *ptr++);
   }
   if(SemaphoreUart)
      OS_SemaphorePost(SemaphoreUart);
}
 
 
void UartPrintfCritical(const char *format,
                        int arg0, int arg1, int arg2, int arg3,
                        int arg4, int arg5, int arg6, int arg7)
{
   uint8 *ptr;
   uint32 state;
 
   state = OS_CriticalBegin();
   sprintf(PrintfString, format, arg0, arg1, arg2, arg3,
           arg4, arg5, arg6, arg7);
   ptr = (uint8*)PrintfString;
   while(*ptr)
   {
      while((MemoryRead(IRQ_STATUS) & IRQ_UART_WRITE_AVAILABLE) == 0)
         ;
      MemoryWrite(UART_WRITE, *ptr++);
   }
   memset(PrintfString, 0, sizeof(PrintfString));
   OS_CriticalEnd(state);
}
 
 
void UartScanf(const char *format,
               int arg0, int arg1, int arg2, int arg3,
               int arg4, int arg5, int arg6, int arg7)
{
   int index = 0, ch;
   OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   for(;;)
   {
      ch = UartRead();
      if(ch != '\b' || index)
         UartWrite(ch);
      if(ch == '\n' || ch == '\r')
         break;
      else if(ch == '\b')
      {
         if(index)
         {
            UartWrite(' ');
            UartWrite(ch);
            --index;
         }
      }
      else if(index < sizeof(PrintfString))
         PrintfString[index++] = (uint8)ch;
   }
   UartWrite('\n');
   PrintfString[index] = 0;
   sscanf(PrintfString, format, arg0, arg1, arg2, arg3,
          arg4, arg5, arg6, arg7);
   OS_SemaphorePost(SemaphoreUart);
}
 
 
/******************************************/
#ifndef WIN32
int puts(const char *string)
{
   uint8 *ptr;
   OS_SemaphorePend(SemaphoreUart, OS_WAIT_FOREVER);
   ptr = (uint8*)string;
   while(*ptr)
   {
      if(*ptr == '\n')
         UartWrite('\r');
      UartWrite(*ptr++);
   }
   OS_SemaphorePost(SemaphoreUart);
   return 0;
}
 
 
int getch(void)
{
   return BufferRead(ReadBuffer, 1);
}
 
 
int kbhit(void)
{
   return ReadBuffer->read != ReadBuffer->write;
}
#endif
 
 
/******************************************/
#if 0
int LogArray[100], LogIndex;
void LogWrite(int a)
{
   if(LogIndex < sizeof(LogArray)/4)
      LogArray[LogIndex++] = a;
}
 
void LogDump(void)
{
   int i;
   for(i = 0; i < LogIndex; ++i)
   {
      if(LogArray[i] > 0xfff)
         UartPrintfCritical("\n", 0,0,0,0,0,0,0,0);
      UartPrintfCritical("0x%x ", LogArray[i], 0,0,0,0,0,0,0);
   }
   LogIndex = 0;
}
#endif