/**
* @file
*
* 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.
*
* This driver uses the termios pseudo driver.
*/
/*
* 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.
*
* COPYRIGHT (c) 1989-2012.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <stdlib.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <rtems/ringbuf.h>
#include <rtems/bspIo.h>
#include <rtems/termiostypes.h>
#include <libchip/serial.h>
#include <libchip/sersupp.h>
#include <bsp.h>
#include "ns16550_p.h"
#include "ns16550.h"
#if defined(BSP_FEATURE_IRQ_EXTENSION)
#include <bsp/irq.h>
#elif defined(BSP_FEATURE_IRQ_LEGACY)
#include <bsp/irq.h>
#elif defined(__PPC__) || defined(__i386__)
#include <bsp/irq.h>
#define BSP_FEATURE_IRQ_LEGACY
#ifdef BSP_SHARED_HANDLER_SUPPORT
#define BSP_FEATURE_IRQ_LEGACY_SHARED_HANDLER_SUPPORT
#endif
#endif
typedef struct {
uint8_t ucModemCtrl;
int transmitFifoChars;
} NS16550Context;
/*
* Driver functions
*/
NS16550_STATIC void ns16550_init(int minor);
NS16550_STATIC int ns16550_open(
int major,
int minor,
void * arg
);
NS16550_STATIC int ns16550_close(
int major,
int minor,
void * arg
);
NS16550_STATIC void ns16550_write_polled(
int minor,
char cChar
);
NS16550_STATIC int ns16550_assert_RTS(
int minor
);
NS16550_STATIC int ns16550_negate_RTS(
int minor
);
NS16550_STATIC int ns16550_assert_DTR(
int minor
);
NS16550_STATIC int ns16550_negate_DTR(
int minor
);
NS16550_STATIC void ns16550_initialize_interrupts(int minor);
NS16550_STATIC void ns16550_cleanup_interrupts(int minor);
NS16550_STATIC ssize_t ns16550_write_support_int(
int minor,
const char *buf,
size_t len
);
NS16550_STATIC ssize_t ns16550_write_support_polled(
int minor,
const char *buf,
size_t len
);
int ns16550_inbyte_nonblocking_polled(
int minor
);
NS16550_STATIC void ns16550_enable_interrupts(
console_tbl *c,
int mask
);
NS16550_STATIC int ns16550_set_attributes(
int minor,
const struct termios *t
);
#if defined(BSP_FEATURE_IRQ_EXTENSION) || defined(BSP_FEATURE_IRQ_LEGACY)
NS16550_STATIC void ns16550_isr(void *arg);
#endif
static rtems_interrupt_lock ns16550_lock =
RTEMS_INTERRUPT_LOCK_INITIALIZER("NS16550");
/*
* Flow control is only supported when using interrupts
*/
const console_flow ns16550_flow_RTSCTS = {
ns16550_negate_RTS, /* deviceStopRemoteTx */
ns16550_assert_RTS /* deviceStartRemoteTx */
};
const console_flow ns16550_flow_DTRCTS = {
ns16550_negate_DTR, /* deviceStopRemoteTx */
ns16550_assert_DTR /* deviceStartRemoteTx */
};
const console_fns ns16550_fns = {
libchip_serial_default_probe, /* deviceProbe */
ns16550_open, /* deviceFirstOpen */
ns16550_close, /* deviceLastClose */
NULL, /* deviceRead */
ns16550_write_support_int, /* deviceWrite */
ns16550_init, /* deviceInitialize */
ns16550_write_polled, /* deviceWritePolled */
ns16550_set_attributes, /* deviceSetAttributes */
true /* deviceOutputUsesInterrupts */
};
const 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 */
};
static uint32_t NS16550_GetBaudDivisor(const console_tbl *c, uint32_t baud)
{
uint32_t clock = c->ulClock;
uint32_t baudDivisor = (clock != 0 ? clock : 115200) / (baud * 16);
if (c->deviceType == SERIAL_NS16550_WITH_FDR) {
uint32_t fractionalDivider = 0x10;
uint32_t err = baud;
uint32_t mulVal;
uint32_t divAddVal;
clock /= 16 * baudDivisor;
for (mulVal = 1; mulVal < 16; ++mulVal) {
for (divAddVal = 0; divAddVal < mulVal; ++divAddVal) {
uint32_t actual = (mulVal * clock) / (mulVal + divAddVal);
uint32_t newErr = actual > baud ? actual - baud : baud - actual;
if (newErr < err) {
err = newErr;
fractionalDivider = (mulVal << 4) | divAddVal;
}
}
}
(*c->setRegister)(
c->ulCtrlPort1,
NS16550_FRACTIONAL_DIVIDER,
fractionalDivider
);
}
return baudDivisor;
}
/*
* ns16550_init
*/
void ns16550_init(int minor)
{
uintptr_t pNS16550;
uint8_t ucDataByte;
uint32_t ulBaudDivisor;
NS16550Context *pns16550Context;
setRegister_f setReg;
getRegister_f getReg;
console_tbl *c = Console_Port_Tbl [minor];
pns16550Context=(NS16550Context *)malloc(sizeof(NS16550Context));
if (pns16550Context == NULL) {
printk( "%s: Error: Not enough memory\n", __func__);
rtems_fatal_error_occurred( 0xdeadbeef);
}
Console_Port_Data[minor].pDeviceContext=(void *)pns16550Context;
pns16550Context->ucModemCtrl=SP_MODEM_IRQ;
pNS16550 = c->ulCtrlPort1;
setReg = c->setRegister;
getReg = c->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( c, NS16550_DISABLE_ALL_INTR );
/* Set the divisor latch and set the baud rate. */
ulBaudDivisor = NS16550_GetBaudDivisor(c, (uintptr_t) c->pDeviceParams);
ucDataByte = SP_LINE_DLAB;
(*setReg)(pNS16550, NS16550_LINE_CONTROL, ucDataByte);
/* XXX */
(*setReg)(pNS16550,NS16550_TRANSMIT_BUFFER,(uint8_t)(ulBaudDivisor & 0xffU));
(*setReg)(
pNS16550,NS16550_INTERRUPT_ENABLE,
(uint8_t)(( ulBaudDivisor >> 8 ) & 0xffU )
);
/* 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(c, NS16550_DISABLE_ALL_INTR);
/* Set data terminal ready. */
/* And open interrupt tristate line */
(*setReg)(pNS16550, NS16550_MODEM_CONTROL,pns16550Context->ucModemCtrl);
(*getReg)(pNS16550, NS16550_LINE_STATUS );
(*getReg)(pNS16550, NS16550_RECEIVE_BUFFER );
}
/*
* ns16550_open
*/
int ns16550_open(
int major,
int minor,
void *arg
)
{
rtems_libio_open_close_args_t *oc = (rtems_libio_open_close_args_t *) arg;
struct rtems_termios_tty *tty = (struct rtems_termios_tty *) oc->iop->data1;
console_tbl *c = Console_Port_Tbl [minor];
console_data *d = &Console_Port_Data [minor];
d->termios_data = tty;
/* Assert DTR */
if (c->pDeviceFlow != &ns16550_flow_DTRCTS) {
ns16550_assert_DTR( minor);
}
/* Set initial baud */
rtems_termios_set_initial_baud( tty, (intptr_t) c->pDeviceParams);
if (c->pDeviceFns->deviceOutputUsesInterrupts) {
ns16550_initialize_interrupts( minor);
ns16550_enable_interrupts( c, NS16550_ENABLE_ALL_INTR_EXCEPT_TX);
}
return RTEMS_SUCCESSFUL;
}
/*
* ns16550_close
*/
int ns16550_close(
int major,
int minor,
void * arg
)
{
console_tbl *c = Console_Port_Tbl [minor];
/*
* Negate DTR
*/
if (c->pDeviceFlow != &ns16550_flow_DTRCTS) {
ns16550_negate_DTR(minor);
}
ns16550_enable_interrupts(c, NS16550_DISABLE_ALL_INTR);
if (c->pDeviceFns->deviceOutputUsesInterrupts) {
ns16550_cleanup_interrupts(minor);
}
return(RTEMS_SUCCESSFUL);
}
/**
* @brief Polled write for NS16550.
*/
void ns16550_outch_polled(console_tbl *c, char out)
{
uintptr_t port = c->ulCtrlPort1;
getRegister_f get = c->getRegister;
setRegister_f set = c->setRegister;
uint32_t status = 0;
rtems_interrupt_lock_context lock_context;
/* Save port interrupt mask */
uint32_t interrupt_mask = get( port, NS16550_INTERRUPT_ENABLE);
/* Disable port interrupts */
ns16550_enable_interrupts( c, NS16550_DISABLE_ALL_INTR);
while (true) {
/* Try to transmit the character in a critical section */
rtems_interrupt_lock_acquire(&ns16550_lock, &lock_context);
/* Read the transmitter holding register and check it */
status = get( port, NS16550_LINE_STATUS);
if ((status & SP_LSR_THOLD) != 0) {
/* Transmit character */
set( port, NS16550_TRANSMIT_BUFFER, out);
/* Finished */
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
break;
} else {
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
}
/* Wait for transmitter holding register to be empty */
do {
status = get( port, NS16550_LINE_STATUS);
} while ((status & SP_LSR_THOLD) == 0);
}
/* Restore port interrupt mask */
set( port, NS16550_INTERRUPT_ENABLE, interrupt_mask);
}
void ns16550_write_polled(int minor, char out)
{
console_tbl *c = Console_Port_Tbl [minor];
ns16550_outch_polled( c, out );
}
/*
* These routines provide control of the RTS and DTR lines
*/
/*
* ns16550_assert_RTS
*/
NS16550_STATIC int ns16550_assert_RTS(int minor)
{
uint32_t pNS16550;
rtems_interrupt_lock_context lock_context;
NS16550Context *pns16550Context;
setRegister_f setReg;
pns16550Context=(NS16550Context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor]->ulCtrlPort1;
setReg = Console_Port_Tbl[minor]->setRegister;
/*
* Assert RTS
*/
rtems_interrupt_lock_acquire(&ns16550_lock, &lock_context);
pns16550Context->ucModemCtrl|=SP_MODEM_RTS;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
return 0;
}
/*
* ns16550_negate_RTS
*/
NS16550_STATIC int ns16550_negate_RTS(int minor)
{
uint32_t pNS16550;
rtems_interrupt_lock_context lock_context;
NS16550Context *pns16550Context;
setRegister_f setReg;
pns16550Context=(NS16550Context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor]->ulCtrlPort1;
setReg = Console_Port_Tbl[minor]->setRegister;
/*
* Negate RTS
*/
rtems_interrupt_lock_acquire(&ns16550_lock, &lock_context);
pns16550Context->ucModemCtrl&=~SP_MODEM_RTS;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
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;
rtems_interrupt_lock_context lock_context;
NS16550Context *pns16550Context;
setRegister_f setReg;
pns16550Context=(NS16550Context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor]->ulCtrlPort1;
setReg = Console_Port_Tbl[minor]->setRegister;
/*
* Assert DTR
*/
rtems_interrupt_lock_acquire(&ns16550_lock, &lock_context);
pns16550Context->ucModemCtrl|=SP_MODEM_DTR;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL, pns16550Context->ucModemCtrl);
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
return 0;
}
/*
* ns16550_negate_DTR
*/
NS16550_STATIC int ns16550_negate_DTR(int minor)
{
uint32_t pNS16550;
rtems_interrupt_lock_context lock_context;
NS16550Context *pns16550Context;
setRegister_f setReg;
pns16550Context=(NS16550Context *) Console_Port_Data[minor].pDeviceContext;
pNS16550 = Console_Port_Tbl[minor]->ulCtrlPort1;
setReg = Console_Port_Tbl[minor]->setRegister;
/*
* Negate DTR
*/
rtems_interrupt_lock_acquire(&ns16550_lock, &lock_context);
pns16550Context->ucModemCtrl&=~SP_MODEM_DTR;
(*setReg)(pNS16550, NS16550_MODEM_CONTROL,pns16550Context->ucModemCtrl);
rtems_interrupt_lock_release(&ns16550_lock, &lock_context);
return 0;
}
/*
* ns16550_set_attributes
*
* This function sets the channel to reflect the requested termios
* port settings.
*/
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;
rtems_interrupt_lock_context lock_context;
const console_tbl *c = Console_Port_Tbl [minor];
pNS16550 = c->ulCtrlPort1;
setReg = c->setRegister;
/*
* Calculate the baud rate divisor
*/
baud_requested = rtems_termios_baud_to_number(t->c_cflag);
ulBaudDivisor = NS16550_GetBaudDivisor(c, 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_lock_acquire(&ns16550_lock, &lock_context);
/*
* Set the baud rate
*
* NOTE: When the Divisor Latch Access Bit (DLAB) is set to 1,
* the transmit buffer and interrupt enable registers
* turn into the LSB and MSB divisor latch registers.
*/
(*setReg)(pNS16550, NS16550_LINE_CONTROL, SP_LINE_DLAB);
(*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_lock_release(&ns16550_lock, &lock_context);
return 0;
}
#if defined(BSP_FEATURE_IRQ_EXTENSION) || defined(BSP_FEATURE_IRQ_LEGACY)
/**
* @brief Process interrupt.
*/
NS16550_STATIC void ns16550_process( int minor)
{
console_tbl *c = Console_Port_Tbl [minor];
console_data *d = &Console_Port_Data [minor];
NS16550Context *ctx = d->pDeviceContext;
uint32_t port = c->ulCtrlPort1;
getRegister_f get = c->getRegister;
int i = 0;
char buf [SP_FIFO_SIZE];
/* Iterate until no more interrupts are pending */
do {
/* Fetch received characters */
for (i = 0; i < SP_FIFO_SIZE; ++i) {
if ((get( port, NS16550_LINE_STATUS) & SP_LSR_RDY) != 0) {
buf [i] = (char) get(port, NS16550_RECEIVE_BUFFER);
} else {
break;
}
}
/* Enqueue fetched characters */
rtems_termios_enqueue_raw_characters( d->termios_data, buf, i);
/* Check if we can dequeue transmitted characters */
if (ctx->transmitFifoChars > 0
&& (get( port, NS16550_LINE_STATUS) & SP_LSR_THOLD) != 0) {
/* Dequeue transmitted characters */
rtems_termios_dequeue_characters(
d->termios_data,
ctx->transmitFifoChars
);
}
} while ((get( port, NS16550_INTERRUPT_ID) & SP_IID_0) == 0);
}
#endif
/**
* @brief Transmits up to @a len characters from @a buf.
*
* This routine is invoked either from task context with disabled interrupts to
* start a new transmission process with exactly one character in case of an
* idle output state or from the interrupt handler to refill the transmitter.
*
* Returns always zero.
*/
ssize_t ns16550_write_support_int(
int minor,
const char *buf,
size_t len
)
{
console_tbl *c = Console_Port_Tbl [minor];
console_data *d = &Console_Port_Data [minor];
NS16550Context *ctx = d->pDeviceContext;
uint32_t port = c->ulCtrlPort1;
setRegister_f set = c->setRegister;
int i = 0;
int out = len > SP_FIFO_SIZE ? SP_FIFO_SIZE : len;
for (i = 0; i < out; ++i) {
set( port, NS16550_TRANSMIT_BUFFER, buf [i]);
}
ctx->transmitFifoChars = out;
if (out > 0) {
ns16550_enable_interrupts( c, NS16550_ENABLE_ALL_INTR);
} else {
ns16550_enable_interrupts( c, NS16550_ENABLE_ALL_INTR_EXCEPT_TX);
}
return 0;
}
/*
* ns16550_enable_interrupts
*
* This routine initializes the port to have the specified interrupts masked.
*/
NS16550_STATIC void ns16550_enable_interrupts(
console_tbl *c,
int mask
)
{
uint32_t pNS16550;
setRegister_f setReg;
pNS16550 = c->ulCtrlPort1;
setReg = c->setRegister;
(*setReg)(pNS16550, NS16550_INTERRUPT_ENABLE, mask);
}
#if defined(BSP_FEATURE_IRQ_EXTENSION) || defined(BSP_FEATURE_IRQ_LEGACY)
void ns16550_isr(void *arg)
{
int minor = (int) arg;
ns16550_process( minor);
}
#endif
/*
* ns16550_initialize_interrupts
*
* This routine initializes the port to operate in interrupt driver mode.
*/
NS16550_STATIC void ns16550_initialize_interrupts( int minor)
{
#if defined(BSP_FEATURE_IRQ_EXTENSION) || defined(BSP_FEATURE_IRQ_LEGACY)
console_tbl *c = Console_Port_Tbl [minor];
#endif
#ifdef BSP_FEATURE_IRQ_EXTENSION
{
rtems_status_code sc = RTEMS_SUCCESSFUL;
sc = rtems_interrupt_handler_install(
c->ulIntVector,
"NS16550",
RTEMS_INTERRUPT_SHARED,
ns16550_isr,
(void *) minor
);
if (sc != RTEMS_SUCCESSFUL) {
/* FIXME */
printk( "%s: Error: Install interrupt handler\n", __func__);
rtems_fatal_error_occurred( 0xdeadbeef);
}
}
#elif defined(BSP_FEATURE_IRQ_LEGACY)
{
int rv = 0;
#ifdef BSP_FEATURE_IRQ_LEGACY_SHARED_HANDLER_SUPPORT
rtems_irq_connect_data cd = {
c->ulIntVector,
ns16550_isr,
(void *) minor,
NULL,
NULL,
NULL,
NULL
};
rv = BSP_install_rtems_shared_irq_handler( &cd);
#else
rtems_irq_connect_data cd = {
c->ulIntVector,
ns16550_isr,
(void *) minor,
NULL,
NULL,
NULL
};
rv = BSP_install_rtems_irq_handler( &cd);
#endif
if (rv == 0) {
/* FIXME */
printk( "%s: Error: Install interrupt handler\n", __func__);
rtems_fatal_error_occurred( 0xdeadbeef);
}
}
#endif
}
NS16550_STATIC void ns16550_cleanup_interrupts(int minor)
{
#if defined(BSP_FEATURE_IRQ_EXTENSION)
rtems_status_code sc = RTEMS_SUCCESSFUL;
console_tbl *c = Console_Port_Tbl [minor];
sc = rtems_interrupt_handler_remove(
c->ulIntVector,
ns16550_isr,
(void *) minor
);
if (sc != RTEMS_SUCCESSFUL) {
/* FIXME */
printk("%s: Error: Remove interrupt handler\n", __func__);
rtems_fatal_error_occurred(0xdeadbeef);
}
#elif defined(BSP_FEATURE_IRQ_LEGACY)
int rv = 0;
console_tbl *c = Console_Port_Tbl [minor];
rtems_irq_connect_data cd = {
.name = c->ulIntVector,
.hdl = ns16550_isr,
.handle = (void *) minor
};
rv = BSP_remove_rtems_irq_handler(&cd);
if (rv == 0) {
/* FIXME */
printk("%s: Error: Remove interrupt handler\n", __func__);
rtems_fatal_error_occurred(0xdeadbeef);
}
#endif
}
/*
* ns16550_write_support_polled
*
* Console Termios output entry point.
*
*/
ssize_t ns16550_write_support_polled(
int minor,
const char *buf,
size_t 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;
}
/*
* Debug gets() support
*/
int ns16550_inch_polled(
console_tbl *c
)
{
uint32_t pNS16550;
unsigned char ucLineStatus;
uint8_t cChar;
getRegister_f getReg;
pNS16550 = c->ulCtrlPort1;
getReg = c->getRegister;
ucLineStatus = (*getReg)(pNS16550, NS16550_LINE_STATUS);
if (ucLineStatus & SP_LSR_RDY) {
cChar = (*getReg)(pNS16550, NS16550_RECEIVE_BUFFER);
return (int)cChar;
}
return -1;
}
/*
* ns16550_inbyte_nonblocking_polled
*
* Console Termios polling input entry point.
*/
int ns16550_inbyte_nonblocking_polled(int minor)
{
console_tbl *c = Console_Port_Tbl [minor];
return ns16550_inch_polled( c );
}