/*
* 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 <rtems/ringbuf.h>
#include <libchip/serial.h>
#include <libchip/sersupp.h>
#include "ns16550_p.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 */
NULL, /* deviceLastClose */
NULL, /* deviceRead */
ns16550_write_support_int, /* deviceWrite */
ns16550_initialize_interrupts, /* deviceInitialize */
ns16550_write_polled, /* deviceWritePolled */
ns16550_set_attributes, /* deviceSetAttributes */
TRUE /* 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 */
ns16550_set_attributes, /* deviceSetAttributes */
FALSE /* deviceOutputUsesInterrupts */
};
extern void set_vector( rtems_isr_entry, rtems_vector_number, int );
/*
* ns16550_init
*/
NS16550_STATIC void ns16550_init(int minor)
{
uint32_t pNS16550;
uint8_t ucTrash;
uint8_t ucDataByte;
uint32_t 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);
ns16550_enable_interrupts(minor, NS16550_DISABLE_ALL_INTR);
/* Set the divisor latch and set the baud rate. */
ulBaudDivisor = NS16550_Baud(
(uint32_t) Console_Port_Tbl[minor].ulClock,
(uint32_t) Console_Port_Tbl[minor].pDeviceParams
);
ucDataByte = SP_LINE_DLAB;
(*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte);
/* XXX */
(*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);
ns16550_enable_interrupts(minor, NS16550_DISABLE_ALL_INTR);
/* 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_open
*/
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_close
*/
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
)
{
uint32_t 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 0
if(_System_state_Is_up(_System_state_Get())) {
rtems_task_wake_after(RTEMS_YIELD_PROCESSOR);
}
#endif
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)
{
uint32_t pNS16550;
uint32_t 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)
{
uint32_t pNS16550;
uint32_t 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)
{
uint32_t pNS16550;
uint32_t 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)
{
uint32_t pNS16550;
uint32_t 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_set_attributes
*
* This function sets the channel to reflect the requested termios
* port settings.
*/
NS16550_STATIC int ns16550_set_attributes(
int minor,
const struct termios *t
)
{
uint32_t pNS16550;
uint32_t ulBaudDivisor;
uint8_t ucLineControl;
uint32_t baud_requested;
setRegister_f setReg;
getRegister_f getReg;
uint32_t Irql;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
getReg = Console_Port_Tbl[minor].getRegister;
/*
* Calculate the baud rate divisor
*/
baud_requested = t->c_cflag & CBAUD;
if (!baud_requested)
baud_requested = B9600; /* default to 9600 baud */
ulBaudDivisor = NS16550_Baud(
(uint32_t) Console_Port_Tbl[minor].ulClock,
termios_baud_to_number(baud_requested)
);
ucLineControl = 0;
/*
* Parity
*/
if (t->c_cflag & PARENB) {
ucLineControl |= SP_LINE_PAR;
if (!(t->c_cflag & PARODD))
ucLineControl |= SP_LINE_ODD;
}
/*
* Character Size
*/
if (t->c_cflag & CSIZE) {
switch (t->c_cflag & CSIZE) {
case CS5: ucLineControl |= FIVE_BITS; break;
case CS6: ucLineControl |= SIX_BITS; break;
case CS7: ucLineControl |= SEVEN_BITS; break;
case CS8: ucLineControl |= EIGHT_BITS; break;
}
} else {
ucLineControl |= EIGHT_BITS; /* default to 9600,8,N,1 */
}
/*
* Stop Bits
*/
if (t->c_cflag & CSTOPB) {
ucLineControl |= SP_LINE_STOP; /* 2 stop bits */
} else {
; /* 1 stop bit */
}
/*
* Now actually set the chip
*/
rtems_interrupt_disable(Irql);
/*
* Set the baud rate
*/
(*setReg)(pNS16550, NS16550_LINE_CONTROL, SP_LINE_DLAB);
/* XXX are these registers right? */
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, ulBaudDivisor&0xff);
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, (ulBaudDivisor>>8)&0xff);
/*
* Now write the line control
*/
(*setReg)(pNS16550, NS16550_LINE_CONTROL, ucLineControl );
rtems_interrupt_enable(Irql);
return 0;
}
/*
* ns16550_process
*
* This routine is the console interrupt handler for A port.
*/
NS16550_STATIC void ns16550_process(
int minor
)
{
uint32_t pNS16550;
volatile uint8_t ucLineStatus;
volatile uint8_t ucInterruptId;
unsigned 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
);
}
/*
* TX all the characters we can
*/
while(TRUE) {
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;
}
#if 0
/* XXX flow control not completely supported in libchip */
if(Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_RTSCTS) {
ns16550_negate_RTS(minor);
}
#endif
rtems_termios_dequeue_characters(Console_Port_Data[minor].termios_data, 1);
if (rtems_termios_dequeue_characters(
Console_Port_Data[minor].termios_data, 1)) {
if (Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_RTSCTS) {
ns16550_negate_RTS(minor);
}
Console_Port_Data[minor].bActive = FALSE;
ns16550_enable_interrupts(minor, NS16550_ENABLE_ALL_INTR_EXCEPT_TX);
break;
}
ucInterruptId = (*getReg)(pNS16550, NS16550_INTERRUPT_ID);
}
} while((ucInterruptId&0xf)!=0x1);
}
/*
* ns16550_isr
*/
NS16550_STATIC rtems_isr ns16550_isr(
rtems_vector_number vector
)
{
int minor;
for(minor=0;minor<Console_Port_Count;minor++) {
if(Console_Port_Tbl[minor].ulIntVector == vector &&
Console_Port_Tbl[minor].deviceType == SERIAL_NS16550 ) {
ns16550_process(minor);
}
}
}
/*
* ns16550_enable_interrupts
*
* This routine initializes the port to have the specified interrupts masked.
*/
NS16550_STATIC void ns16550_enable_interrupts(
int minor,
int mask
)
{
uint32_t pNS16550;
setRegister_f setReg;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
setReg = Console_Port_Tbl[minor].setRegister;
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, mask);
}
/*
* ns16550_initialize_interrupts
*
* This routine initializes the port to operate in interrupt driver mode.
*/
NS16550_STATIC void ns16550_initialize_interrupts(int minor)
{
ns16550_init(minor);
Console_Port_Data[minor].bActive = FALSE;
set_vector(ns16550_isr, Console_Port_Tbl[minor].ulIntVector, 1);
ns16550_enable_interrupts(minor, NS16550_ENABLE_ALL_INTR);
}
/*
* ns16550_write_support_int
*
* Console Termios output entry point.
*/
NS16550_STATIC int ns16550_write_support_int(
int minor,
const char *buf,
int len
)
{
uint32_t Irql;
uint32_t pNS16550;
setRegister_f setReg;
setReg = Console_Port_Tbl[minor].setRegister;
pNS16550 = Console_Port_Tbl[minor].ulCtrlPort1;
/*
* We are using interrupt driven output and termios only sends us
* one character at a time.
*/
if ( !len )
return 0;
if(Console_Port_Tbl[minor].pDeviceFlow != &ns16550_flow_RTSCTS) {
ns16550_assert_RTS(minor);
}
rtems_interrupt_disable(Irql);
if ( Console_Port_Data[minor].bActive == FALSE) {
Console_Port_Data[minor].bActive = TRUE;
ns16550_enable_interrupts(minor, NS16550_ENABLE_ALL_INTR);
}
(*setReg)(pNS16550, NS16550_TRANSMIT_BUFFER, *buf);
rtems_interrupt_enable(Irql);
return 1;
}
/*
* 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
)
{
uint32_t 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;
}
}