altera_up_avalon_rs232.c

Builder uses to integrate a larger system module. Each component consists of a structured set of fi

/******************************************************************************
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* License Agreement                                                           *
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* Copyright (c) 2007 Altera Corporation, San Jose, California, USA.           *
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#include <errno.h>

#include <priv/alt_file.h>

#include "altera_up_avalon_rs232.h"
#include "altera_up_avalon_rs232_regs.h"


void alt_up_rs232_enable_read_interrupt(alt_up_rs232_dev *rs232)
{
	alt_u32 ctrl_reg;
	ctrl_reg = IORD_ALT_UP_RS232_CONTROL(rs232->base); 
	// set RE to 1 while maintaining other bits the same
	ctrl_reg |= ALT_UP_RS232_CONTROL_RE_MSK;
	IOWR_ALT_UP_RS232_CONTROL(rs232->base, ctrl_reg);
}

void alt_up_rs232_disable_read_interrupt(alt_up_rs232_dev *rs232)
{
	alt_u32 ctrl_reg;
	ctrl_reg = IORD_ALT_UP_RS232_CONTROL(rs232->base); 
	// set RE to 0 while maintaining other bits the same
	ctrl_reg &= ~ALT_UP_RS232_CONTROL_RE_MSK;
	IOWR_ALT_UP_RS232_CONTROL(rs232->base, ctrl_reg);
}

unsigned alt_up_rs232_get_num_chars_in_read_FIFO(alt_up_rs232_dev *rs232)
{
	alt_u16 ravail = 0;
	// we can only read the 16 bits for RAVAIL --- a read of DATA will discard the data
	ravail = IORD_16DIRECT(IOADDR_ALT_UP_RS232_DATA(rs232->base), 2); 
	return ravail;
}

unsigned alt_up_rs232_get_num_chars_in_write_FIFO(alt_up_rs232_dev *rs232)
{
	alt_u32 ctrl_reg;
	ctrl_reg = IORD_16DIRECT(rs232->base, 1); 
	return (ctrl_reg & ALT_UP_RS232_CONTROL_WSPACE_MSK) >> ALT_UP_RS232_CONTROL_WSPACE_OFST;
}

int alt_up_rs232_check_parity(alt_u32 data_reg)
{
	unsigned parity_error = (data_reg & ALT_UP_RS232_DATA_PE_MSK) >> ALT_UP_RS232_DATA_PE_OFST;
	return (parity_error ? -1 : 0);
}

int alt_up_rs232_write_data(alt_up_rs232_dev *rs232, alt_u8 data)
{
	alt_u32 data_reg;
	data_reg = IORD_ALT_UP_RS232_DATA(rs232->base);

	// we can write directly without thinking about other bit fields for this
	// case ONLY, because only DATA field of the data register is writable
	IOWR_ALT_UP_RS232_DATA(rs232->base, (data>>ALT_UP_RS232_DATA_DATA_OFST) & ALT_UP_RS232_DATA_DATA_MSK);
	return 0;
}

int alt_up_rs232_read_data(alt_up_rs232_dev *rs232, alt_u8 *data)
{
	alt_u32 data_reg;
	data_reg = IORD_ALT_UP_RS232_DATA(rs232->base);
	*data = (data_reg & ALT_UP_RS232_DATA_DATA_MSK) >> ALT_UP_RS232_DATA_DATA_OFST;
	return alt_up_rs232_check_parity(data_reg);
}

int alt_up_rs232_read_fd (alt_fd* fd, char* ptr, int len)
{
	alt_up_rs232_dev *rs232 = (alt_up_rs232_dev*)fd->dev;
	int count = 0;
	while(len--)
	{
		if (alt_up_rs232_read_data(rs232, ptr++)==0)
			count++;
		else
			break;
	}
	return count;
}

int alt_up_rs232_write_fd (alt_fd* fd, const char* ptr, int len)
{
	alt_up_rs232_dev *rs232 = (alt_up_rs232_dev*)fd->dev;
	int count = 0;
	while(len--)
	{
		if (alt_up_rs232_write_data(rs232, ptr++)==0)
			count++;
		else
			break;
	}
	return count;
}

alt_up_rs232_dev* alt_up_rs232_open_dev(const char* name)
{
  // find the device from the device list 
  // (see altera_hal/HAL/inc/priv/alt_file.h 
  // and altera_hal/HAL/src/alt_find_dev.c 
  // for details)
  alt_up_rs232_dev *dev = (alt_up_rs232_dev*)alt_find_dev(name, &alt_dev_list);

  return dev;
}