/*
* This file contains the TTY driver for the National Semiconductor NS16550.
*
* This part is widely cloned and second sourced. It is found in a number
* of "Super IO" controllers.
*
* COPYRIGHT (c) 1998 by Radstone Technology
*
*
* THIS FILE IS PROVIDED TO YOU, THE USER, "AS IS", WITHOUT WARRANTY OF ANY
* KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK
* AS TO THE QUALITY AND PERFORMANCE OF ALL CODE IN THIS FILE IS WITH YOU.
*
* You are hereby granted permission to use, copy, modify, and distribute
* this file, provided that this notice, plus the above copyright notice
* and disclaimer, appears in all copies. Radstone Technology will provide
* no support for this code.
*
* This driver uses the termios pseudo driver.
*/
#include <rtems.h>
#include <rtems/libio.h>
#include <stdlib.h>
#include <ringbuf.h>
#include <libchip/serial.h>
#include "ns16550_p.h"
#include "sersupp.h"
/*
* Flow control is only supported when using interrupts
*/
console_flow ns16550_flow_RTSCTS =
{
ns16550_negate_RTS, /* deviceStopRemoteTx */
ns16550_assert_RTS /* deviceStartRemoteTx */
};
console_flow ns16550_flow_DTRCTS =
{
ns16550_negate_DTR, /* deviceStopRemoteTx */
ns16550_assert_DTR /* deviceStartRemoteTx */
};
console_fns ns16550_fns =
{
libchip_serial_default_probe, /* deviceProbe */
ns16550_open, /* deviceFirstOpen */
ns16550_flush, /* deviceLastClose */
NULL, /* deviceRead */
ns16550_write_support_int, /* deviceWrite */
ns16550_initialize_interrupts, /* deviceInitialize */
ns16550_write_polled, /* deviceWritePolled */
NULL, /* deviceSetAttributes */
FALSE, /* deviceOutputUsesInterrupts */
};
console_fns ns16550_fns_polled =
{
libchip_serial_default_probe, /* deviceProbe */
ns16550_open, /* deviceFirstOpen */
ns16550_close, /* deviceLastClose */
ns16550_inbyte_nonblocking_polled, /* deviceRead */
ns16550_write_support_polled, /* deviceWrite */
ns16550_init, /* deviceInitialize */
ns16550_write_polled, /* deviceWritePolled */
NULL, /* deviceSetAttributes */
FALSE, /* deviceOutputUsesInterrupts */
};
extern void set_vector( rtems_isr_entry, rtems_vector_number, int );
NS16550_STATIC void ns16550_init(int minor)
{
unsigned32 pNS16550;
unsigned8 ucTrash;
unsigned8 ucDataByte;
unsigned32 ulBaudDivisor;
ns16550_context *pns16550Context;
setRegister_f setReg;
getRegister_f getReg;
pns16550Context=(ns16550_context *)malloc(sizeof(ns16550_context));
Console_Port_Data[minor].pDeviceContext=(void *)pns16550Context;
pns16550Context->ucModemCtrl=SP_MODEM_IRQ;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
getReg = Console_Port_Tbl[minor].getRegister;
/* Clear the divisor latch, clear all interrupt enables,
* and reset and
* disable the FIFO's.
*/
(*setReg)(pNS16550, NS16550_LINE_CONTROL, 0x0);
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, 0x0);
/* Set the divisor latch and set the baud rate. */
ulBaudDivisor=NS16550_Baud((unsigned32)Console_Port_Tbl[minor].pDeviceParams);
ucDataByte = SP_LINE_DLAB;
(*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte);
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, ulBaudDivisor&0xff);
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, (ulBaudDivisor>>8)&0xff);
/* Clear the divisor latch and set the character size to eight bits */
/* with one stop bit and no parity checking. */
ucDataByte = EIGHT_BITS;
(*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte);
/* Enable and reset transmit and receive FIFOs. TJA */
ucDataByte = SP_FIFO_ENABLE;
(*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte);
ucDataByte = SP_FIFO_ENABLE | SP_FIFO_RXRST | SP_FIFO_TXRST;
(*setReg)(pNS16550, NS16550_FIFO_CONTROL, ucDataByte);
/*
* Disable interrupts
*/
ucDataByte = 0;
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, ucDataByte);
/* Set data terminal ready. */
/* And open interrupt tristate line */
(*setReg)(pNS16550, NS16550_MODEM_CONTROL,pns16550Context->ucModemCtrl);
ucTrash = (*getReg)(pNS16550, NS16550_LINE_STATUS );
ucTrash = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER );
}
NS16550_STATIC int ns16550_open(
int major,
int minor,
void * arg
)
{
/*
* Assert DTR
*/
if(Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_DTRCTS) {
ns16550_assert_DTR(minor);
}
return(RTEMS_SUCCESSFUL);
}
NS16550_STATIC int ns16550_close(
int major,
int minor,
void * arg
)
{
/*
* Negate DTR
*/
if(Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_DTRCTS) {
ns16550_negate_DTR(minor);
}
return(RTEMS_SUCCESSFUL);
}
/*
* ns16550_write_polled
*/
NS16550_STATIC void ns16550_write_polled(
int minor,
char cChar
)
{
unsigned32 pNS16550;
unsigned char ucLineStatus;
int iTimeout;
getRegister_f getReg;
setRegister_f setReg;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
getReg = Console_Port_Tbl[minor].getRegister;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* wait for transmitter holding register to be empty
*/
iTimeout=1000;
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
while ((ucLineStatus & SP_LSR_THOLD) == 0) {
/*
* Yield while we wait
*/
if(_System_state_Is_up(_System_state_Get())) {
rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
}
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
if(!--iTimeout) {
break;
}
}
/*
* transmit character
*/
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, cChar);
}
/*
* These routines provide control of the RTS and DTR lines
*/
/*
* ns16550_assert_RTS
*/
NS16550_STATIC int ns16550_assert_RTS(int minor)
{
unsigned32 pNS16550;
unsigned32 Irql;
ns16550_context *pns16550Context;
setRegister_f setReg;
pns16550Context=(ns16550_context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* Assert RTS
*/
rtems_interrupt_disable(Irql);
pns16550Context->ucModemCtrl|=SP_MODEM_RTS;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_enable(Irql);
return 0;
}
/*
* ns16550_negate_RTS
*/
NS16550_STATIC int ns16550_negate_RTS(int minor)
{
unsigned32 pNS16550;
unsigned32 Irql;
ns16550_context *pns16550Context;
setRegister_f setReg;
pns16550Context=(ns16550_context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* Negate RTS
*/
rtems_interrupt_disable(Irql);
pns16550Context->ucModemCtrl&=~SP_MODEM_RTS;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_enable(Irql);
return 0;
}
/*
* These flow control routines utilise a connection from the local DTR
* line to the remote CTS line
*/
/*
* ns16550_assert_DTR
*/
NS16550_STATIC int ns16550_assert_DTR(int minor)
{
unsigned32 pNS16550;
unsigned32 Irql;
ns16550_context *pns16550Context;
setRegister_f setReg;
pns16550Context=(ns16550_context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* Assert DTR
*/
rtems_interrupt_disable(Irql);
pns16550Context->ucModemCtrl|=SP_MODEM_DTR;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_enable(Irql);
return 0;
}
/*
* ns16550_negate_DTR
*/
NS16550_STATIC int ns16550_negate_DTR(int minor)
{
unsigned32 pNS16550;
unsigned32 Irql;
ns16550_context *pns16550Context;
setRegister_f setReg;
pns16550Context=(ns16550_context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* Negate DTR
*/
rtems_interrupt_disable(Irql);
pns16550Context->ucModemCtrl&=~SP_MODEM_DTR;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL,pns16550Context->ucModemCtrl);
rtems_interrupt_enable(Irql);
return 0;
}
/*
* ns16550_isr
*
* This routine is the console interrupt handler for COM1 and COM2
*
* Input parameters:
* vector - vector number
*
* Output parameters: NONE
*
* Return values: NONE
*/
NS16550_STATIC void ns16550_process(
int minor
)
{
unsigned32 pNS16550;
volatile unsigned8 ucLineStatus;
volatile unsigned8 ucInterruptId;
char cChar;
getRegister_f getReg;
setRegister_f setReg;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
getReg = Console_Port_Tbl[minor].getRegister;
setReg = Console_Port_Tbl[minor].setRegister;
do {
/*
* Deal with any received characters
*/
while(TRUE) {
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
if(~ucLineStatus & SP_LSR_RDY) {
break;
}
cChar = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER);
rtems_termios_enqueue_raw_characters(
Console_Port_Data[minor].termios_data,
&cChar,
1
);
}
while(TRUE) {
if(Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
Console_Port_Data[minor].bActive=FALSE;
if(Console_Port_Tbl[minor].pDeviceFlow !=&ns16550_flow_RTSCTS) {
ns16550_negate_RTS(minor);
}
/*
* There is no data to transmit
*/
break;
}
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
if(~ucLineStatus & SP_LSR_THOLD) {
/*
* We'll get another interrupt when
* the transmitter holding reg. becomes
* free again
*/
break;
}
Ring_buffer_Remove_character( &Console_Port_Data[minor].TxBuffer, cChar);
/*
* transmit character
*/
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, cChar);
}
ucInterruptId = (*getReg)(pNS16550, NS16550_INTERRUPT_ID);
}
while((ucInterruptId&0xf)!=0x1);
}
NS16550_STATIC rtems_isr ns16550_isr(
rtems_vector_number vector
)
{
int minor;
for(minor=0;minor<Console_Port_Count;minor++) {
if(vector==Console_Port_Tbl[minor].ulIntVector) {
ns16550_process(minor);
}
}
}
/*
* ns16550_flush
*/
NS16550_STATIC int ns16550_flush(int major, int minor, void *arg)
{
while(!Ring_buffer_Is_empty(&Console_Port_Data[minor].TxBuffer)) {
/*
* Yield while we wait
*/
if(_System_state_Is_up(_System_state_Get())) {
rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
}
}
ns16550_close(major, minor, arg);
return(RTEMS_SUCCESSFUL);
}
/*
* ns16550_initialize_interrupts
*
* This routine initializes the console's receive and transmit
* ring buffers and loads the appropriate vectors to handle the interrupts.
*
* Input parameters: NONE
*
* Output parameters: NONE
*
* Return values: NONE
*/
NS16550_STATIC void ns16550_enable_interrupts(
int minor
)
{
unsigned32 pNS16550;
unsigned8 ucDataByte;
setRegister_f setReg;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
/*
* Enable interrupts
*/
ucDataByte = SP_INT_RX_ENABLE | SP_INT_TX_ENABLE;
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, ucDataByte);
}
NS16550_STATIC void ns16550_initialize_interrupts(int minor)
{
ns16550_init(minor);
Ring_buffer_Initialize(&Console_Port_Data[minor].TxBuffer);
Console_Port_Data[minor].bActive = FALSE;
set_vector(ns16550_isr, Console_Port_Tbl[minor].ulIntVector, 1);
ns16550_enable_interrupts(minor);
}
/*
* ns16550_write_support_int
*
* Console Termios output entry point.
*
*/
NS16550_STATIC int ns16550_write_support_int(
int minor,
const char *buf,
int len
)
{
int i;
unsigned32 Irql;
for(i=0; i<len;) {
if(Ring_buffer_Is_full(&Console_Port_Data[minor].TxBuffer)) {
if(!Console_Port_Data[minor].bActive) {
/*
* Wake up the device
*/
rtems_interrupt_disable(Irql);
Console_Port_Data[minor].bActive = TRUE;
if(Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_RTSCTS) {
ns16550_assert_RTS(minor);
}
ns16550_process(minor);
rtems_interrupt_enable(Irql);
} else {
/*
* Yield
*/
rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
}
/*
* Wait for ring buffer to empty
*/
continue;
}
else {
Ring_buffer_Add_character( &Console_Port_Data[minor].TxBuffer, buf[i]);
i++;
}
}
/*
* Ensure that characters are on the way
*/
if(!Console_Port_Data[minor].bActive) {
/*
* Wake up the device
*/
rtems_interrupt_disable(Irql);
Console_Port_Data[minor].bActive = TRUE;
if(Console_Port_Tbl[minor].pDeviceFlow !=&ns16550_flow_RTSCTS) {
ns16550_assert_RTS(minor);
}
ns16550_process(minor);
rtems_interrupt_enable(Irql);
}
return (len);
}
/*
* ns16550_write_support_polled
*
* Console Termios output entry point.
*
*/
NS16550_STATIC int ns16550_write_support_polled(
int minor,
const char *buf,
int len
)
{
int nwrite = 0;
/*
* poll each byte in the string out of the port.
*/
while (nwrite < len) {
/*
* transmit character
*/
ns16550_write_polled(minor, *buf++);
nwrite++;
}
/*
* return the number of bytes written.
*/
return nwrite;
}
/*
* ns16550_inbyte_nonblocking_polled
*
* Console Termios polling input entry point.
*/
NS16550_STATIC int ns16550_inbyte_nonblocking_polled(
int minor
)
{
unsigned32 pNS16550;
unsigned char ucLineStatus;
char cChar;
getRegister_f getReg;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
getReg = Console_Port_Tbl[minor].getRegister;
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
if(ucLineStatus & SP_LSR_RDY) {
cChar = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER);
return (int)cChar;
} else {
return -1;
}
}