/******************************************************************************/
/******************************************************************************/
/*  UART.H - TLC16C550C UART driver routines                                  */
/*                                                                            */
/*       This module is the device library for the TLC16C550C UART on the     */
/*       54XX DSK board.                                                      */
/*                                                                            */
/*  MACRO FUNCTIONS:                                                          */
/*                                                                            */
/*  FUNCTIONS:                                                                */
/*                                                                            */
/*    uart_init() - Perform required initialization and default configuration */
/*    uart_reset() - Reset the codec                                          */
/*    int uart_read_reg() - Read uart register                                */
/*    int uart_write_reg() - Write uart register                              */
/*    uart_interrupt_control() - Enables uart interrupts                      */
/*    uart_interrupt_hook() - Install ISR for uart interrupt                  */
/*    uart_interrupt_info() - retrieves interrupt information from IIR        */
/*    int uart_read() - Read a buffer of data from uart                       */
/*    int uart_write() - Write a buffer of data to uart                       */
/*    int uart_setup() - change values of settable parameters                 */
/*    int uart_fgetc() - read a character from the uart.                      */
/*    int uart_fputc() - write a character to the uart.                       */
/*    char* uart_fgets() - read a string from the uart.                       */
/*    int uart_fputs() - write a string to the uart.                          */
/*                                                                            */
/******************************************************************************/
#ifndef _UART_H_
#define _UART_H_

#include  <type.h>
#include  <board.h>         /* public header file                             */

/*****************************************************************************/
/* DEFINES                                                                   */
/*****************************************************************************/
#undef OK
#define OK          0

#undef ERROR
#define ERROR       -1

#define DLAB_SET_REG            0x0100

//C54XX interrupt the uart is mapped to
#define UART_INTR_FLAG          INT1
#define UART_INTR_TRAP          INT1_TRAP

//LCR
#define UART_STOPBIT_ENABLE     0x04
#define UART_PARITY_ENABLE      0x08
#define UART_PARITY_SELECT      0x10
#define DLAB_MASK               0x80
//MCR
#define UART_LOOP_ENABLE        0x10

//FCR
#define FIFO_TRIG01             0x00
#define FIFO_TRIG04             0x01
#define FIFO_TRIG08             0x10
#define FIFO_TRIG14             0x11

//uart register addresses
volatile ioport u16 port4000;
volatile ioport u16 port4001;
volatile ioport u16 port4002;
volatile ioport u16 port4003;
volatile ioport u16 port4004;
volatile ioport u16 port4005;
volatile ioport u16 port4006;
volatile ioport u16 port4007;

//uart registers
#define UART_RBR_REG port4000
#define UART_THR_REG port4000
#define UART_IER_REG port4001
#define UART_IIR_REG port4002
#define UART_FCR_REG port4002
#define UART_LCR_REG port4003
#define UART_MCR_REG port4004
#define UART_LSR_REG port4005
#define UART_MSR_REG port4006
#define UART_SCR_REG port4007

//for these registers ensure DLAB=1 (b7 of LCR) before accessing
#define UART_DLL_REG port4000
#define UART_DLM_REG port4001

/*****************************************************************************/
/* typedefs & enums                                                          */
/*****************************************************************************/
//TL16C550C UART registers
//If b8 of register enumeration equals 1 (UART_DLL & UART_DLM), it implies DLAB 
//must be set to 1 before register can be addressed.
//The actual port address used in the portio routines is the enumerated value 
//with b8 set to zero.
//
//e.g. to read UART_DLL,
//
//      unsigned int val;
//      UART_LCR_REG |= 0x80
//      val = portRead(UART_DLL & ~0x0100) 
//
typedef enum
{
   UART_RBR = 0x4000,                    // rx buffer  
   UART_THR = 0x4000,                    // tx hold
   UART_IER = 0x4001,                    // interrupt enable
   UART_IIR = 0x4002,                    // interrupt identification  
   UART_FCR = 0x4002,                    // FIFO control 
   UART_LCR = 0x4003,                    // line control 
   UART_MCR = 0x4004,                    // modem control 
   UART_LSR = 0x4005,                    // line status
   UART_MSR = 0x4006,                    // modem status
   UART_SCR = 0x4007,                    // scratch  
   UART_DLL = 0x4100,                    // divisor latch (LSB)
   UART_DLM = 0x4101                     // divisor latch (MSB)
} UartReg, *PUartReg;

// TL16C550C UART interrupts
typedef enum
{
   UART_RINT          = 0x01,             // Enable rx data available interrupt
   UART_TINT          = 0x02,             // Enable tx hold register empty interrupt
   UART_LSINT         = 0x04,             // Enable rx line status interrupt
   UART_MSINT         = 0x08,             // Enable modem status interrupt
   UART_ALLINT        = 0x0f              // Enable all interrupts
} UartIntr, *PUartIntr;

// TL16C550C UART serial character word length
typedef enum
{
   UART_WORD_NOCHANGE   = -1,             // 5-bit 
   UART_WORD5           = 0x00,           // 5-bit 
   UART_WORD6           = 0x01,           // 6-bit
   UART_WORD7           = 0x02,           // 7-bit
   UART_WORD8           = 0x03            // 8-bit
} UartWordLen, *PUartWordLen;

// TL16C550C UART stop bits
typedef enum
{
   UART_STOPBITS_NOCHANGE   = -1,
   UART_STOP1               = 0,             // 1 stop bit
   UART_STOP1_PLUS_HALF     = 1,             // 1 1/2 stop bits
   UART_STOP2               = 2              // 2 stop bits
} UartStopBits, *PUartStopBits;

// TL16C550C UART flow control
typedef enum
{
   UART_LOOP_NOCHANGE = -1,
   UART_LOOPBACK      = 0,
   UART_NO_LOOPBACK   = 1
} UartLoop, *PUArtLoop;

// TL16C550C UART parity select
typedef enum
{
   UART_PARITY_NOCHANGE = -1,     //disable parity checking
   UART_DISABLE_PARITY  = 0,      //disable parity checking
   UART_EVEN_PARITY     = 0x10,   //enable even parity
   UART_ODD_PARITY      = ~0x10   //enable odd parity
} UartParity, *PUartParity;

// TL16C550C UART baud rates
typedef enum
{
   UART_BAUD_NOCHANGE   = -1,
   UART_BAUD_50         = 4608,
   UART_BAUD_75         = 3072,
   UART_BAUD_110        = 2094,
   UART_BAUD_150        = 1536,
   UART_BAUD_300        = 768,
   UART_BAUD_600        = 384,
   UART_BAUD_1200       = 192,
   UART_BAUD_1800       = 128,
   UART_BAUD_2000       = 116,
   UART_BAUD_2400       = 96,
   UART_BAUD_3600       = 64,
   UART_BAUD_4800       = 48,
   UART_BAUD_7200       = 32,
   UART_BAUD_9600       = 24,
   UART_BAUD_19200      = 12,
   UART_BAUD_38400      = 6,
   UART_BAUD_57600      = 4,
   UART_BAUD_115200     = 2
} UartBaud, *PUartBaud;

// TL16C550C UART FIFO control
typedef enum
{
   UART_FIFO_NOCHANGE   = -1,
   UART_FIFO_ENABLE     = 0x01,
   UART_FIFO_RX_RESET   = 0x02,
   UART_FIFO_TX_RESET   = 0x04,
   UART_FIFO_DMA        = 0x08,
   UART_FIFO_TRG_RX_LSB = 0x40,
   UART_FIFO_TRG_RX_MSB = 0x80,
   UART_FIFO_DISABLE    = 0x10,

   //FIFO rx trigger levels (1, 4, 8, or 14 bytes)
   UART_FIFO_TRIG01     = 0x11,
   UART_FIFO_TRIG04     = 0x12,
   UART_FIFO_TRIG08     = 0x13,
   UART_FIFO_TRIG14     = 0x14
} UartFifoControl, *PUartFifoControl;

//TL16C550C UART interrupt information as indicated
//by b0-b3 of UART_IIR_REG
typedef enum
{
   UART_LSR_INTR        = 0x1, //rx line status - overrun error, parity error,  
                               //framing error, or break interrupt. Read line  
                               //status register to determine exact interrupt 
                               //source.
   UART_RXRDY_INTR      = 0x6, //rx data available
   UART_CHAR_TIMEOUT    = 0xc, //character timeout
   UART_TXRDY_INTR      = 0x2, //tx holding register empty
   UART_MSR_INTR        = 0x1  //modem status - clear to send, data set ready,
                               //ring indicator, or data carrier detect.
                               //Read modem status register to exact interrupt 
                               //source.
} UartIntrInfo, *PUartIntrInfo;

/*****************************************************************************/
/* PUBLIC FUNCTION PROTOTYPES                                                */
/*****************************************************************************/

/*****************************************************************************/
/*  s16 uart_init(void)                                                       */
/*                                                                           */ 
/*  This routine performs required initialization and default configuration. */
/*                                                                           */
/*  Parameters:                                                              */
/*      - None                                                               */
/*                                                                           */ 
/*  Return:                                                                  */
/*  - OK success                                                             */
/*  - ERROR failure                                                          */
/*                                                                           */ 
/*  Notes:                                                                   */
/*                                                                           */ 
/*****************************************************************************/
int uart_init(void);

/*****************************************************************************/
/*  s16 uart_reset(void)                                                     */
/*                                                                           */
/*  This routine resets the TLC16C550 ACE internal registers to their        */
/*  default values.                                                          */