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amiserial.c
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amiserial.c
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/*
* linux/drivers/char/amiserial.c
*
* Serial driver for the amiga builtin port.
*
* This code was created by taking serial.c version 4.30 from kernel
* release 2.3.22, replacing all hardware related stuff with the
* corresponding amiga hardware actions, and removing all irrelevant
* code. As a consequence, it uses many of the constants and names
* associated with the registers and bits of 16550 compatible UARTS -
* but only to keep track of status, etc in the state variables. It
* was done this was to make it easier to keep the code in line with
* (non hardware specific) changes to serial.c.
*
* The port is registered with the tty driver as minor device 64, and
* therefore other ports should should only use 65 upwards.
*
* Richard Lucock 28/12/99
*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997,
* 1998, 1999 Theodore Ts'o
*
*/
/*
* Serial driver configuration section. Here are the various options:
*
* SERIAL_PARANOIA_CHECK
* Check the magic number for the async_structure where
* ever possible.
*/
#include <linux/delay.h>
#undef SERIAL_PARANOIA_CHECK
#define SERIAL_DO_RESTART
/* Set of debugging defines */
#undef SERIAL_DEBUG_INTR
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
/* Sanity checks */
#if defined(MODULE) && defined(SERIAL_DEBUG_MCOUNT)
#define DBG_CNT(s) printk("(%s): [%x] refc=%d, serc=%d, ttyc=%d -> %s\n", \
tty->name, (info->flags), serial_driver->refcount,info->count,tty->count,s)
#else
#define DBG_CNT(s)
#endif
/*
* End of serial driver configuration section.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <linux/serialP.h>
#include <linux/serial_reg.h>
static char *serial_version = "4.30";
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/console.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>
#include <asm/setup.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#define custom amiga_custom
static char *serial_name = "Amiga-builtin serial driver";
static struct tty_driver *serial_driver;
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
static struct async_struct *IRQ_ports;
static unsigned char current_ctl_bits;
static void change_speed(struct async_struct *info, struct ktermios *old);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
static struct serial_state rs_table[1];
#define NR_PORTS ARRAY_SIZE(rs_table)
#include <asm/uaccess.h>
#define serial_isroot() (capable(CAP_SYS_ADMIN))
static inline int serial_paranoia_check(struct async_struct *info,
char *name, const char *routine)
{
#ifdef SERIAL_PARANOIA_CHECK
static const char *badmagic =
"Warning: bad magic number for serial struct (%s) in %s\n";
static const char *badinfo =
"Warning: null async_struct for (%s) in %s\n";
if (!info) {
printk(badinfo, name, routine);
return 1;
}
if (info->magic != SERIAL_MAGIC) {
printk(badmagic, name, routine);
return 1;
}
#endif
return 0;
}
/* some serial hardware definitions */
#define SDR_OVRUN (1<<15)
#define SDR_RBF (1<<14)
#define SDR_TBE (1<<13)
#define SDR_TSRE (1<<12)
#define SERPER_PARENB (1<<15)
#define AC_SETCLR (1<<15)
#define AC_UARTBRK (1<<11)
#define SER_DTR (1<<7)
#define SER_RTS (1<<6)
#define SER_DCD (1<<5)
#define SER_CTS (1<<4)
#define SER_DSR (1<<3)
static __inline__ void rtsdtr_ctrl(int bits)
{
ciab.pra = ((bits & (SER_RTS | SER_DTR)) ^ (SER_RTS | SER_DTR)) | (ciab.pra & ~(SER_RTS | SER_DTR));
}
/*
* ------------------------------------------------------------
* rs_stop() and rs_start()
*
* This routines are called before setting or resetting tty->stopped.
* They enable or disable transmitter interrupts, as necessary.
* ------------------------------------------------------------
*/
static void rs_stop(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_stop"))
return;
local_irq_save(flags);
if (info->IER & UART_IER_THRI) {
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
local_irq_restore(flags);
}
static void rs_start(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_start"))
return;
local_irq_save(flags);
if (info->xmit.head != info->xmit.tail
&& info->xmit.buf
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
}
/*
* ----------------------------------------------------------------------
*
* Here starts the interrupt handling routines. All of the following
* subroutines are declared as inline and are folded into
* rs_interrupt(). They were separated out for readability's sake.
*
* Note: rs_interrupt() is a "fast" interrupt, which means that it
* runs with interrupts turned off. People who may want to modify
* rs_interrupt() should try to keep the interrupt handler as fast as
* possible. After you are done making modifications, it is not a bad
* idea to do:
*
* gcc -S -DKERNEL -Wall -Wstrict-prototypes -O6 -fomit-frame-pointer serial.c
*
* and look at the resulting assemble code in serial.s.
*
* - Ted Ts'o ([email protected]), 7-Mar-93
* -----------------------------------------------------------------------
*/
/*
* This routine is used by the interrupt handler to schedule
* processing in the software interrupt portion of the driver.
*/
static void rs_sched_event(struct async_struct *info,
int event)
{
info->event |= 1 << event;
tasklet_schedule(&info->tlet);
}
static void receive_chars(struct async_struct *info)
{
int status;
int serdatr;
struct tty_struct *tty = info->tty;
unsigned char ch, flag;
struct async_icount *icount;
int oe = 0;
icount = &info->state->icount;
status = UART_LSR_DR; /* We obviously have a character! */
serdatr = custom.serdatr;
mb();
custom.intreq = IF_RBF;
mb();
if((serdatr & 0x1ff) == 0)
status |= UART_LSR_BI;
if(serdatr & SDR_OVRUN)
status |= UART_LSR_OE;
ch = serdatr & 0xff;
icount->rx++;
#ifdef SERIAL_DEBUG_INTR
printk("DR%02x:%02x...", ch, status);
#endif
flag = TTY_NORMAL;
/*
* We don't handle parity or frame errors - but I have left
* the code in, since I'm not sure that the errors can't be
* detected.
*/
if (status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE)) {
/*
* For statistics only
*/
if (status & UART_LSR_BI) {
status &= ~(UART_LSR_FE | UART_LSR_PE);
icount->brk++;
} else if (status & UART_LSR_PE)
icount->parity++;
else if (status & UART_LSR_FE)
icount->frame++;
if (status & UART_LSR_OE)
icount->overrun++;
/*
* Now check to see if character should be
* ignored, and mask off conditions which
* should be ignored.
*/
if (status & info->ignore_status_mask)
goto out;
status &= info->read_status_mask;
if (status & (UART_LSR_BI)) {
#ifdef SERIAL_DEBUG_INTR
printk("handling break....");
#endif
flag = TTY_BREAK;
if (info->flags & ASYNC_SAK)
do_SAK(tty);
} else if (status & UART_LSR_PE)
flag = TTY_PARITY;
else if (status & UART_LSR_FE)
flag = TTY_FRAME;
if (status & UART_LSR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
oe = 1;
}
}
tty_insert_flip_char(tty, ch, flag);
if (oe == 1)
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
tty_flip_buffer_push(tty);
out:
return;
}
static void transmit_chars(struct async_struct *info)
{
custom.intreq = IF_TBE;
mb();
if (info->x_char) {
custom.serdat = info->x_char | 0x100;
mb();
info->state->icount.tx++;
info->x_char = 0;
return;
}
if (info->xmit.head == info->xmit.tail
|| info->tty->stopped
|| info->tty->hw_stopped) {
info->IER &= ~UART_IER_THRI;
custom.intena = IF_TBE;
mb();
return;
}
custom.serdat = info->xmit.buf[info->xmit.tail++] | 0x100;
mb();
info->xmit.tail = info->xmit.tail & (SERIAL_XMIT_SIZE-1);
info->state->icount.tx++;
if (CIRC_CNT(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) < WAKEUP_CHARS)
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
#ifdef SERIAL_DEBUG_INTR
printk("THRE...");
#endif
if (info->xmit.head == info->xmit.tail) {
custom.intena = IF_TBE;
mb();
info->IER &= ~UART_IER_THRI;
}
}
static void check_modem_status(struct async_struct *info)
{
unsigned char status = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
unsigned char dstatus;
struct async_icount *icount;
/* Determine bits that have changed */
dstatus = status ^ current_ctl_bits;
current_ctl_bits = status;
if (dstatus) {
icount = &info->state->icount;
/* update input line counters */
if (dstatus & SER_DSR)
icount->dsr++;
if (dstatus & SER_DCD) {
icount->dcd++;
#ifdef CONFIG_HARD_PPS
if ((info->flags & ASYNC_HARDPPS_CD) &&
!(status & SER_DCD))
hardpps();
#endif
}
if (dstatus & SER_CTS)
icount->cts++;
wake_up_interruptible(&info->delta_msr_wait);
}
if ((info->flags & ASYNC_CHECK_CD) && (dstatus & SER_DCD)) {
#if (defined(SERIAL_DEBUG_OPEN) || defined(SERIAL_DEBUG_INTR))
printk("ttyS%d CD now %s...", info->line,
(!(status & SER_DCD)) ? "on" : "off");
#endif
if (!(status & SER_DCD))
wake_up_interruptible(&info->open_wait);
else {
#ifdef SERIAL_DEBUG_OPEN
printk("doing serial hangup...");
#endif
if (info->tty)
tty_hangup(info->tty);
}
}
if (info->flags & ASYNC_CTS_FLOW) {
if (info->tty->hw_stopped) {
if (!(status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx start...");
#endif
info->tty->hw_stopped = 0;
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
return;
}
} else {
if ((status & SER_CTS)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
printk("CTS tx stop...");
#endif
info->tty->hw_stopped = 1;
info->IER &= ~UART_IER_THRI;
/* disable Tx interrupt and remove any pending interrupts */
custom.intena = IF_TBE;
mb();
custom.intreq = IF_TBE;
mb();
}
}
}
}
static irqreturn_t ser_vbl_int( int irq, void *data)
{
/* vbl is just a periodic interrupt we tie into to update modem status */
struct async_struct * info = IRQ_ports;
/*
* TBD - is it better to unregister from this interrupt or to
* ignore it if MSI is clear ?
*/
if(info->IER & UART_IER_MSI)
check_modem_status(info);
return IRQ_HANDLED;
}
static irqreturn_t ser_rx_int(int irq, void *dev_id)
{
struct async_struct * info;
#ifdef SERIAL_DEBUG_INTR
printk("ser_rx_int...");
#endif
info = IRQ_ports;
if (!info || !info->tty)
return IRQ_NONE;
receive_chars(info);
info->last_active = jiffies;
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
return IRQ_HANDLED;
}
static irqreturn_t ser_tx_int(int irq, void *dev_id)
{
struct async_struct * info;
if (custom.serdatr & SDR_TBE) {
#ifdef SERIAL_DEBUG_INTR
printk("ser_tx_int...");
#endif
info = IRQ_ports;
if (!info || !info->tty)
return IRQ_NONE;
transmit_chars(info);
info->last_active = jiffies;
#ifdef SERIAL_DEBUG_INTR
printk("end.\n");
#endif
}
return IRQ_HANDLED;
}
/*
* -------------------------------------------------------------------
* Here ends the serial interrupt routines.
* -------------------------------------------------------------------
*/
/*
* This routine is used to handle the "bottom half" processing for the
* serial driver, known also the "software interrupt" processing.
* This processing is done at the kernel interrupt level, after the
* rs_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This
* is where time-consuming activities which can not be done in the
* interrupt driver proper are done; the interrupt driver schedules
* them using rs_sched_event(), and they get done here.
*/
static void do_softint(unsigned long private_)
{
struct async_struct *info = (struct async_struct *) private_;
struct tty_struct *tty;
tty = info->tty;
if (!tty)
return;
if (test_and_clear_bit(RS_EVENT_WRITE_WAKEUP, &info->event))
tty_wakeup(tty);
}
/*
* ---------------------------------------------------------------
* Low level utility subroutines for the serial driver: routines to
* figure out the appropriate timeout for an interrupt chain, routines
* to initialize and startup a serial port, and routines to shutdown a
* serial port. Useful stuff like that.
* ---------------------------------------------------------------
*/
static int startup(struct async_struct * info)
{
unsigned long flags;
int retval=0;
unsigned long page;
page = get_zeroed_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
local_irq_save(flags);
if (info->flags & ASYNC_INITIALIZED) {
free_page(page);
goto errout;
}
if (info->xmit.buf)
free_page(page);
else
info->xmit.buf = (unsigned char *) page;
#ifdef SERIAL_DEBUG_OPEN
printk("starting up ttys%d ...", info->line);
#endif
/* Clear anything in the input buffer */
custom.intreq = IF_RBF;
mb();
retval = request_irq(IRQ_AMIGA_VERTB, ser_vbl_int, 0, "serial status", info);
if (retval) {
if (serial_isroot()) {
if (info->tty)
set_bit(TTY_IO_ERROR,
&info->tty->flags);
retval = 0;
}
goto errout;
}
/* enable both Rx and Tx interrupts */
custom.intena = IF_SETCLR | IF_RBF | IF_TBE;
mb();
info->IER = UART_IER_MSI;
/* remember current state of the DCD and CTS bits */
current_ctl_bits = ciab.pra & (SER_DCD | SER_CTS | SER_DSR);
IRQ_ports = info;
info->MCR = 0;
if (info->tty->termios->c_cflag & CBAUD)
info->MCR = SER_DTR | SER_RTS;
rtsdtr_ctrl(info->MCR);
if (info->tty)
clear_bit(TTY_IO_ERROR, &info->tty->flags);
info->xmit.head = info->xmit.tail = 0;
/*
* Set up the tty->alt_speed kludge
*/
if (info->tty) {
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
info->tty->alt_speed = 57600;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
info->tty->alt_speed = 115200;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
info->tty->alt_speed = 230400;
if ((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
info->tty->alt_speed = 460800;
}
/*
* and set the speed of the serial port
*/
change_speed(info, NULL);
info->flags |= ASYNC_INITIALIZED;
local_irq_restore(flags);
return 0;
errout:
local_irq_restore(flags);
return retval;
}
/*
* This routine will shutdown a serial port; interrupts are disabled, and
* DTR is dropped if the hangup on close termio flag is on.
*/
static void shutdown(struct async_struct * info)
{
unsigned long flags;
struct serial_state *state;
if (!(info->flags & ASYNC_INITIALIZED))
return;
state = info->state;
#ifdef SERIAL_DEBUG_OPEN
printk("Shutting down serial port %d ....\n", info->line);
#endif
local_irq_save(flags); /* Disable interrupts */
/*
* clear delta_msr_wait queue to avoid mem leaks: we may free the irq
* here so the queue might never be waken up
*/
wake_up_interruptible(&info->delta_msr_wait);
IRQ_ports = NULL;
/*
* Free the IRQ, if necessary
*/
free_irq(IRQ_AMIGA_VERTB, info);
if (info->xmit.buf) {
free_page((unsigned long) info->xmit.buf);
info->xmit.buf = NULL;
}
info->IER = 0;
custom.intena = IF_RBF | IF_TBE;
mb();
/* disable break condition */
custom.adkcon = AC_UARTBRK;
mb();
if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
info->MCR &= ~(SER_DTR|SER_RTS);
rtsdtr_ctrl(info->MCR);
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
info->flags &= ~ASYNC_INITIALIZED;
local_irq_restore(flags);
}
/*
* This routine is called to set the UART divisor registers to match
* the specified baud rate for a serial port.
*/
static void change_speed(struct async_struct *info,
struct ktermios *old_termios)
{
int quot = 0, baud_base, baud;
unsigned cflag, cval = 0;
int bits;
unsigned long flags;
if (!info->tty || !info->tty->termios)
return;
cflag = info->tty->termios->c_cflag;
/* Byte size is always 8 bits plus parity bit if requested */
cval = 3; bits = 10;
if (cflag & CSTOPB) {
cval |= 0x04;
bits++;
}
if (cflag & PARENB) {
cval |= UART_LCR_PARITY;
bits++;
}
if (!(cflag & PARODD))
cval |= UART_LCR_EPAR;
#ifdef CMSPAR
if (cflag & CMSPAR)
cval |= UART_LCR_SPAR;
#endif
/* Determine divisor based on baud rate */
baud = tty_get_baud_rate(info->tty);
if (!baud)
baud = 9600; /* B0 transition handled in rs_set_termios */
baud_base = info->state->baud_base;
if (baud == 38400 &&
((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
quot = info->state->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
/* If the quotient is zero refuse the change */
if (!quot && old_termios) {
/* FIXME: Will need updating for new tty in the end */
info->tty->termios->c_cflag &= ~CBAUD;
info->tty->termios->c_cflag |= (old_termios->c_cflag & CBAUD);
baud = tty_get_baud_rate(info->tty);
if (!baud)
baud = 9600;
if (baud == 38400 &&
((info->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST))
quot = info->state->custom_divisor;
else {
if (baud == 134)
/* Special case since 134 is really 134.5 */
quot = (2*baud_base / 269);
else if (baud)
quot = baud_base / baud;
}
}
/* As a last resort, if the quotient is zero, default to 9600 bps */
if (!quot)
quot = baud_base / 9600;
info->quot = quot;
info->timeout = ((info->xmit_fifo_size*HZ*bits*quot) / baud_base);
info->timeout += HZ/50; /* Add .02 seconds of slop */
/* CTS flow control flag and modem status interrupts */
info->IER &= ~UART_IER_MSI;
if (info->flags & ASYNC_HARDPPS_CD)
info->IER |= UART_IER_MSI;
if (cflag & CRTSCTS) {
info->flags |= ASYNC_CTS_FLOW;
info->IER |= UART_IER_MSI;
} else
info->flags &= ~ASYNC_CTS_FLOW;
if (cflag & CLOCAL)
info->flags &= ~ASYNC_CHECK_CD;
else {
info->flags |= ASYNC_CHECK_CD;
info->IER |= UART_IER_MSI;
}
/* TBD:
* Does clearing IER_MSI imply that we should disable the VBL interrupt ?
*/
/*
* Set up parity check flag
*/
info->read_status_mask = UART_LSR_OE | UART_LSR_DR;
if (I_INPCK(info->tty))
info->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (I_BRKINT(info->tty) || I_PARMRK(info->tty))
info->read_status_mask |= UART_LSR_BI;
/*
* Characters to ignore
*/
info->ignore_status_mask = 0;
if (I_IGNPAR(info->tty))
info->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (I_IGNBRK(info->tty)) {
info->ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignore parity and break indicators, ignore
* overruns too. (For real raw support).
*/
if (I_IGNPAR(info->tty))
info->ignore_status_mask |= UART_LSR_OE;
}
/*
* !!! ignore all characters if CREAD is not set
*/
if ((cflag & CREAD) == 0)
info->ignore_status_mask |= UART_LSR_DR;
local_irq_save(flags);
{
short serper;
/* Set up the baud rate */
serper = quot - 1;
/* Enable or disable parity bit */
if(cval & UART_LCR_PARITY)
serper |= (SERPER_PARENB);
custom.serper = serper;
mb();
}
info->LCR = cval; /* Save LCR */
local_irq_restore(flags);
}
static int rs_put_char(struct tty_struct *tty, unsigned char ch)
{
struct async_struct *info;
unsigned long flags;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_put_char"))
return 0;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
if (CIRC_SPACE(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) == 0) {
local_irq_restore(flags);
return 0;
}
info->xmit.buf[info->xmit.head++] = ch;
info->xmit.head &= SERIAL_XMIT_SIZE-1;
local_irq_restore(flags);
return 1;
}
static void rs_flush_chars(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
return;
if (info->xmit.head == info->xmit.tail
|| tty->stopped
|| tty->hw_stopped
|| !info->xmit.buf)
return;
local_irq_save(flags);
info->IER |= UART_IER_THRI;
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
static int rs_write(struct tty_struct * tty, const unsigned char *buf, int count)
{
int c, ret = 0;
struct async_struct *info;
unsigned long flags;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_write"))
return 0;
if (!info->xmit.buf)
return 0;
local_irq_save(flags);
while (1) {
c = CIRC_SPACE_TO_END(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE);
if (count < c)
c = count;
if (c <= 0) {
break;
}
memcpy(info->xmit.buf + info->xmit.head, buf, c);
info->xmit.head = ((info->xmit.head + c) &
(SERIAL_XMIT_SIZE-1));
buf += c;
count -= c;
ret += c;
}
local_irq_restore(flags);
if (info->xmit.head != info->xmit.tail
&& !tty->stopped
&& !tty->hw_stopped
&& !(info->IER & UART_IER_THRI)) {
info->IER |= UART_IER_THRI;
local_irq_disable();
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
local_irq_restore(flags);
}
return ret;
}
static int rs_write_room(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_write_room"))
return 0;
return CIRC_SPACE(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static int rs_chars_in_buffer(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
return 0;
return CIRC_CNT(info->xmit.head, info->xmit.tail, SERIAL_XMIT_SIZE);
}
static void rs_flush_buffer(struct tty_struct *tty)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
return;
local_irq_save(flags);
info->xmit.head = info->xmit.tail = 0;
local_irq_restore(flags);
tty_wakeup(tty);
}
/*
* This function is used to send a high-priority XON/XOFF character to
* the device
*/
static void rs_send_xchar(struct tty_struct *tty, char ch)
{
struct async_struct *info = tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_send_char"))
return;
info->x_char = ch;
if (ch) {
/* Make sure transmit interrupts are on */
/* Check this ! */
local_irq_save(flags);
if(!(custom.intenar & IF_TBE)) {
custom.intena = IF_SETCLR | IF_TBE;
mb();
/* set a pending Tx Interrupt, transmitter should restart now */
custom.intreq = IF_SETCLR | IF_TBE;
mb();
}
local_irq_restore(flags);
info->IER |= UART_IER_THRI;
}
}
/*
* ------------------------------------------------------------