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linux/drivers/char/amiserial.c
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp 
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00

2175 lines
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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/config.h>
#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 */
#define SERIAL_INLINE
#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/slab.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <asm/setup.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/amigahw.h>
#include <asm/amigaints.h>
#ifdef SERIAL_INLINE
#define _INLINE_ inline
#endif
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 termios *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)
/*
* tmp_buf is used as a temporary buffer by serial_write. We need to
* lock it in case the copy_from_user blocks while swapping in a page,
* and some other program tries to do a serial write at the same time.
* Since the lock will only come under contention when the system is
* swapping and available memory is low, it makes sense to share one
* buffer across all the serial ports, since it significantly saves
* memory if large numbers of serial ports are open.
*/
static unsigned char *tmp_buf;
static DECLARE_MUTEX(tmp_buf_sem);
#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 = (struct async_struct *)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 = (struct async_struct *)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 (tytso@mit.edu), 7-Mar-93
* -----------------------------------------------------------------------
*/
/*
* This routine is used by the interrupt handler to schedule
* processing in the software interrupt portion of the driver.
*/
static _INLINE_ void rs_sched_event(struct async_struct *info,
int event)
{
info->event |= 1 << event;
tasklet_schedule(&info->tlet);
}
static _INLINE_ 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 _INLINE_ 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 _INLINE_ 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, struct pt_regs *regs)
{
/* 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 pt_regs * regs)
{
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 pt_regs * regs)
{
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);
wake_up_interruptible(&tty->write_wait);
}
}
/*
* ---------------------------------------------------------------
* 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 termios *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) {
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 disbale the VBL interrupt ?
*/
/*
* Set up parity check flag
*/
#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
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 void rs_put_char(struct tty_struct *tty, unsigned char ch)
{
struct async_struct *info;
unsigned long flags;
if (!tty)
return;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_put_char"))
return;
if (!info->xmit.buf)
return;
local_irq_save(flags);
if (CIRC_SPACE(info->xmit.head,
info->xmit.tail,
SERIAL_XMIT_SIZE) == 0) {
local_irq_restore(flags);
return;
}
info->xmit.buf[info->xmit.head++] = ch;
info->xmit.head &= SERIAL_XMIT_SIZE-1;
local_irq_restore(flags);
}
static void rs_flush_chars(struct tty_struct *tty)
{
struct async_struct *info = (struct async_struct *)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;
if (!tty)
return 0;
info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_write"))
return 0;
if (!info->xmit.buf || !tmp_buf)
return 0;
local_save_flags(flags);
local_irq_disable();
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 = (struct async_struct *)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 = (struct async_struct *)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 = (struct async_struct *)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);
wake_up_interruptible(&tty->write_wait);
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 = (struct async_struct *)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;
}
}
/*
* ------------------------------------------------------------
* rs_throttle()
*
* This routine is called by the upper-layer tty layer to signal that
* incoming characters should be throttled.
* ------------------------------------------------------------
*/
static void rs_throttle(struct tty_struct * tty)
{
struct async_struct *info = (struct async_struct *)tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
char buf[64];
printk("throttle %s: %d....\n", tty_name(tty, buf),
tty->ldisc.chars_in_buffer(tty));
#endif
if (serial_paranoia_check(info, tty->name, "rs_throttle"))
return;
if (I_IXOFF(tty))
rs_send_xchar(tty, STOP_CHAR(tty));
if (tty->termios->c_cflag & CRTSCTS)
info->MCR &= ~SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
static void rs_unthrottle(struct tty_struct * tty)
{
struct async_struct *info = (struct async_struct *)tty->driver_data;
unsigned long flags;
#ifdef SERIAL_DEBUG_THROTTLE
char buf[64];
printk("unthrottle %s: %d....\n", tty_name(tty, buf),
tty->ldisc.chars_in_buffer(tty));
#endif
if (serial_paranoia_check(info, tty->name, "rs_unthrottle"))
return;
if (I_IXOFF(tty)) {
if (info->x_char)
info->x_char = 0;
else
rs_send_xchar(tty, START_CHAR(tty));
}
if (tty->termios->c_cflag & CRTSCTS)
info->MCR |= SER_RTS;
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/*
* ------------------------------------------------------------
* rs_ioctl() and friends
* ------------------------------------------------------------
*/
static int get_serial_info(struct async_struct * info,
struct serial_struct * retinfo)
{
struct serial_struct tmp;
struct serial_state *state = info->state;
if (!retinfo)
return -EFAULT;
memset(&tmp, 0, sizeof(tmp));
tmp.type = state->type;
tmp.line = state->line;
tmp.port = state->port;
tmp.irq = state->irq;
tmp.flags = state->flags;
tmp.xmit_fifo_size = state->xmit_fifo_size;
tmp.baud_base = state->baud_base;
tmp.close_delay = state->close_delay;
tmp.closing_wait = state->closing_wait;
tmp.custom_divisor = state->custom_divisor;
if (copy_to_user(retinfo,&tmp,sizeof(*retinfo)))
return -EFAULT;
return 0;
}
static int set_serial_info(struct async_struct * info,
struct serial_struct * new_info)
{
struct serial_struct new_serial;
struct serial_state old_state, *state;
unsigned int change_irq,change_port;
int retval = 0;
if (copy_from_user(&new_serial,new_info,sizeof(new_serial)))
return -EFAULT;
state = info->state;
old_state = *state;
change_irq = new_serial.irq != state->irq;
change_port = (new_serial.port != state->port);
if(change_irq || change_port || (new_serial.xmit_fifo_size != state->xmit_fifo_size))
return -EINVAL;
if (!serial_isroot()) {
if ((new_serial.baud_base != state->baud_base) ||
(new_serial.close_delay != state->close_delay) ||
(new_serial.xmit_fifo_size != state->xmit_fifo_size) ||
((new_serial.flags & ~ASYNC_USR_MASK) !=
(state->flags & ~ASYNC_USR_MASK)))
return -EPERM;
state->flags = ((state->flags & ~ASYNC_USR_MASK) |
(new_serial.flags & ASYNC_USR_MASK));
info->flags = ((info->flags & ~ASYNC_USR_MASK) |
(new_serial.flags & ASYNC_USR_MASK));
state->custom_divisor = new_serial.custom_divisor;
goto check_and_exit;
}
if (new_serial.baud_base < 9600)
return -EINVAL;
/*
* OK, past this point, all the error checking has been done.
* At this point, we start making changes.....
*/
state->baud_base = new_serial.baud_base;
state->flags = ((state->flags & ~ASYNC_FLAGS) |
(new_serial.flags & ASYNC_FLAGS));
info->flags = ((state->flags & ~ASYNC_INTERNAL_FLAGS) |
(info->flags & ASYNC_INTERNAL_FLAGS));
state->custom_divisor = new_serial.custom_divisor;
state->close_delay = new_serial.close_delay * HZ/100;
state->closing_wait = new_serial.closing_wait * HZ/100;
info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
check_and_exit:
if (info->flags & ASYNC_INITIALIZED) {
if (((old_state.flags & ASYNC_SPD_MASK) !=
(state->flags & ASYNC_SPD_MASK)) ||
(old_state.custom_divisor != state->custom_divisor)) {
if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
info->tty->alt_speed = 57600;
if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
info->tty->alt_speed = 115200;
if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
info->tty->alt_speed = 230400;
if ((state->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
info->tty->alt_speed = 460800;
change_speed(info, NULL);
}
} else
retval = startup(info);
return retval;
}
/*
* get_lsr_info - get line status register info
*
* Purpose: Let user call ioctl() to get info when the UART physically
* is emptied. On bus types like RS485, the transmitter must
* release the bus after transmitting. This must be done when
* the transmit shift register is empty, not be done when the
* transmit holding register is empty. This functionality
* allows an RS485 driver to be written in user space.
*/
static int get_lsr_info(struct async_struct * info, unsigned int *value)
{
unsigned char status;
unsigned int result;
unsigned long flags;
local_irq_save(flags);
status = custom.serdatr;
mb();
local_irq_restore(flags);
result = ((status & SDR_TSRE) ? TIOCSER_TEMT : 0);
if (copy_to_user(value, &result, sizeof(int)))
return -EFAULT;
return 0;
}
static int rs_tiocmget(struct tty_struct *tty, struct file *file)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
unsigned char control, status;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
control = info->MCR;
local_irq_save(flags);
status = ciab.pra;
local_irq_restore(flags);
return ((control & SER_RTS) ? TIOCM_RTS : 0)
| ((control & SER_DTR) ? TIOCM_DTR : 0)
| (!(status & SER_DCD) ? TIOCM_CAR : 0)
| (!(status & SER_DSR) ? TIOCM_DSR : 0)
| (!(status & SER_CTS) ? TIOCM_CTS : 0);
}
static int rs_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
local_irq_save(flags);
if (set & TIOCM_RTS)
info->MCR |= SER_RTS;
if (set & TIOCM_DTR)
info->MCR |= SER_DTR;
if (clear & TIOCM_RTS)
info->MCR &= ~SER_RTS;
if (clear & TIOCM_DTR)
info->MCR &= ~SER_DTR;
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
return 0;
}
/*
* rs_break() --- routine which turns the break handling on or off
*/
static void rs_break(struct tty_struct *tty, int break_state)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_break"))
return;
local_irq_save(flags);
if (break_state == -1)
custom.adkcon = AC_SETCLR | AC_UARTBRK;
else
custom.adkcon = AC_UARTBRK;
mb();
local_irq_restore(flags);
}
static int rs_ioctl(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
struct async_icount cprev, cnow; /* kernel counter temps */
struct serial_icounter_struct icount;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
return -ENODEV;
if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
(cmd != TIOCSERCONFIG) && (cmd != TIOCSERGSTRUCT) &&
(cmd != TIOCMIWAIT) && (cmd != TIOCGICOUNT)) {
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
}
switch (cmd) {
case TIOCGSERIAL:
return get_serial_info(info,
(struct serial_struct *) arg);
case TIOCSSERIAL:
return set_serial_info(info,
(struct serial_struct *) arg);
case TIOCSERCONFIG:
return 0;
case TIOCSERGETLSR: /* Get line status register */
return get_lsr_info(info, (unsigned int *) arg);
case TIOCSERGSTRUCT:
if (copy_to_user((struct async_struct *) arg,
info, sizeof(struct async_struct)))
return -EFAULT;
return 0;
/*
* Wait for any of the 4 modem inputs (DCD,RI,DSR,CTS) to change
* - mask passed in arg for lines of interest
* (use |'ed TIOCM_RNG/DSR/CD/CTS for masking)
* Caller should use TIOCGICOUNT to see which one it was
*/
case TIOCMIWAIT:
local_irq_save(flags);
/* note the counters on entry */
cprev = info->state->icount;
local_irq_restore(flags);
while (1) {
interruptible_sleep_on(&info->delta_msr_wait);
/* see if a signal did it */
if (signal_pending(current))
return -ERESTARTSYS;
local_irq_save(flags);
cnow = info->state->icount; /* atomic copy */
local_irq_restore(flags);
if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr &&
cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
return -EIO; /* no change => error */
if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) ||
((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
return 0;
}
cprev = cnow;
}
/* NOTREACHED */
/*
* Get counter of input serial line interrupts (DCD,RI,DSR,CTS)
* Return: write counters to the user passed counter struct
* NB: both 1->0 and 0->1 transitions are counted except for
* RI where only 0->1 is counted.
*/
case TIOCGICOUNT:
local_irq_save(flags);
cnow = info->state->icount;
local_irq_restore(flags);
icount.cts = cnow.cts;
icount.dsr = cnow.dsr;
icount.rng = cnow.rng;
icount.dcd = cnow.dcd;
icount.rx = cnow.rx;
icount.tx = cnow.tx;
icount.frame = cnow.frame;
icount.overrun = cnow.overrun;
icount.parity = cnow.parity;
icount.brk = cnow.brk;
icount.buf_overrun = cnow.buf_overrun;
if (copy_to_user((void *)arg, &icount, sizeof(icount)))
return -EFAULT;
return 0;
case TIOCSERGWILD:
case TIOCSERSWILD:
/* "setserial -W" is called in Debian boot */
printk ("TIOCSER?WILD ioctl obsolete, ignored.\n");
return 0;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static void rs_set_termios(struct tty_struct *tty, struct termios *old_termios)
{
struct async_struct *info = (struct async_struct *)tty->driver_data;
unsigned long flags;
unsigned int cflag = tty->termios->c_cflag;
if ( (cflag == old_termios->c_cflag)
&& ( RELEVANT_IFLAG(tty->termios->c_iflag)
== RELEVANT_IFLAG(old_termios->c_iflag)))
return;
change_speed(info, old_termios);
/* Handle transition to B0 status */
if ((old_termios->c_cflag & CBAUD) &&
!(cflag & CBAUD)) {
info->MCR &= ~(SER_DTR|SER_RTS);
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle transition away from B0 status */
if (!(old_termios->c_cflag & CBAUD) &&
(cflag & CBAUD)) {
info->MCR |= SER_DTR;
if (!(tty->termios->c_cflag & CRTSCTS) ||
!test_bit(TTY_THROTTLED, &tty->flags)) {
info->MCR |= SER_RTS;
}
local_irq_save(flags);
rtsdtr_ctrl(info->MCR);
local_irq_restore(flags);
}
/* Handle turning off CRTSCTS */
if ((old_termios->c_cflag & CRTSCTS) &&
!(tty->termios->c_cflag & CRTSCTS)) {
tty->hw_stopped = 0;
rs_start(tty);
}
#if 0
/*
* No need to wake up processes in open wait, since they
* sample the CLOCAL flag once, and don't recheck it.
* XXX It's not clear whether the current behavior is correct
* or not. Hence, this may change.....
*/
if (!(old_termios->c_cflag & CLOCAL) &&
(tty->termios->c_cflag & CLOCAL))
wake_up_interruptible(&info->open_wait);
#endif
}
/*
* ------------------------------------------------------------
* rs_close()
*
* This routine is called when the serial port gets closed. First, we
* wait for the last remaining data to be sent. Then, we unlink its
* async structure from the interrupt chain if necessary, and we free
* that IRQ if nothing is left in the chain.
* ------------------------------------------------------------
*/
static void rs_close(struct tty_struct *tty, struct file * filp)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
struct serial_state *state;
unsigned long flags;
if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
return;
state = info->state;
local_irq_save(flags);
if (tty_hung_up_p(filp)) {
DBG_CNT("before DEC-hung");
local_irq_restore(flags);
return;
}
#ifdef SERIAL_DEBUG_OPEN
printk("rs_close ttys%d, count = %d\n", info->line, state->count);
#endif
if ((tty->count == 1) && (state->count != 1)) {
/*
* Uh, oh. tty->count is 1, which means that the tty
* structure will be freed. state->count should always
* be one in these conditions. If it's greater than
* one, we've got real problems, since it means the
* serial port won't be shutdown.
*/
printk("rs_close: bad serial port count; tty->count is 1, "
"state->count is %d\n", state->count);
state->count = 1;
}
if (--state->count < 0) {
printk("rs_close: bad serial port count for ttys%d: %d\n",
info->line, state->count);
state->count = 0;
}
if (state->count) {
DBG_CNT("before DEC-2");
local_irq_restore(flags);
return;
}
info->flags |= ASYNC_CLOSING;
/*
* Now we wait for the transmit buffer to clear; and we notify
* the line discipline to only process XON/XOFF characters.
*/
tty->closing = 1;
if (info->closing_wait != ASYNC_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, info->closing_wait);
/*
* At this point we stop accepting input. To do this, we
* disable the receive line status interrupts, and tell the
* interrupt driver to stop checking the data ready bit in the
* line status register.
*/
info->read_status_mask &= ~UART_LSR_DR;
if (info->flags & ASYNC_INITIALIZED) {
/* disable receive interrupts */
custom.intena = IF_RBF;
mb();
/* clear any pending receive interrupt */
custom.intreq = IF_RBF;
mb();
/*
* Before we drop DTR, make sure the UART transmitter
* has completely drained; this is especially
* important if there is a transmit FIFO!
*/
rs_wait_until_sent(tty, info->timeout);
}
shutdown(info);
if (tty->driver->flush_buffer)
tty->driver->flush_buffer(tty);
tty_ldisc_flush(tty);
tty->closing = 0;
info->event = 0;
info->tty = NULL;
if (info->blocked_open) {
if (info->close_delay) {
msleep_interruptible(jiffies_to_msecs(info->close_delay));
}
wake_up_interruptible(&info->open_wait);
}
info->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
wake_up_interruptible(&info->close_wait);
local_irq_restore(flags);
}
/*
* rs_wait_until_sent() --- wait until the transmitter is empty
*/
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
unsigned long orig_jiffies, char_time;
int lsr;
if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
return;
if (info->xmit_fifo_size == 0)
return; /* Just in case.... */
orig_jiffies = jiffies;
/*
* Set the check interval to be 1/5 of the estimated time to
* send a single character, and make it at least 1. The check
* interval should also be less than the timeout.
*
* Note: we have to use pretty tight timings here to satisfy
* the NIST-PCTS.
*/
char_time = (info->timeout - HZ/50) / info->xmit_fifo_size;
char_time = char_time / 5;
if (char_time == 0)
char_time = 1;
if (timeout)
char_time = min_t(unsigned long, char_time, timeout);
/*
* If the transmitter hasn't cleared in twice the approximate
* amount of time to send the entire FIFO, it probably won't
* ever clear. This assumes the UART isn't doing flow
* control, which is currently the case. Hence, if it ever
* takes longer than info->timeout, this is probably due to a
* UART bug of some kind. So, we clamp the timeout parameter at
* 2*info->timeout.
*/
if (!timeout || timeout > 2*info->timeout)
timeout = 2*info->timeout;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("In rs_wait_until_sent(%d) check=%lu...", timeout, char_time);
printk("jiff=%lu...", jiffies);
#endif
while(!((lsr = custom.serdatr) & SDR_TSRE)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("serdatr = %d (jiff=%lu)...", lsr, jiffies);
#endif
msleep_interruptible(jiffies_to_msecs(char_time));
if (signal_pending(current))
break;
if (timeout && time_after(jiffies, orig_jiffies + timeout))
break;
}
current->state = TASK_RUNNING;
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);
#endif
}
/*
* rs_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
static void rs_hangup(struct tty_struct *tty)
{
struct async_struct * info = (struct async_struct *)tty->driver_data;
struct serial_state *state = info->state;
if (serial_paranoia_check(info, tty->name, "rs_hangup"))
return;
state = info->state;
rs_flush_buffer(tty);
shutdown(info);
info->event = 0;
state->count = 0;
info->flags &= ~ASYNC_NORMAL_ACTIVE;
info->tty = NULL;
wake_up_interruptible(&info->open_wait);
}
/*
* ------------------------------------------------------------
* rs_open() and friends
* ------------------------------------------------------------
*/
static int block_til_ready(struct tty_struct *tty, struct file * filp,
struct async_struct *info)
{
#ifdef DECLARE_WAITQUEUE
DECLARE_WAITQUEUE(wait, current);
#else
struct wait_queue wait = { current, NULL };
#endif
struct serial_state *state = info->state;
int retval;
int do_clocal = 0, extra_count = 0;
unsigned long flags;
/*
* If the device is in the middle of being closed, then block
* until it's done, and then try again.
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
if (info->flags & ASYNC_CLOSING)
interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
return ((info->flags & ASYNC_HUP_NOTIFY) ?
-EAGAIN : -ERESTARTSYS);
#else
return -EAGAIN;
#endif
}
/*
* If non-blocking mode is set, or the port is not enabled,
* then make the check up front and then exit.
*/
if ((filp->f_flags & O_NONBLOCK) ||
(tty->flags & (1 << TTY_IO_ERROR))) {
info->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
if (tty->termios->c_cflag & CLOCAL)
do_clocal = 1;
/*
* Block waiting for the carrier detect and the line to become
* free (i.e., not in use by the callout). While we are in
* this loop, state->count is dropped by one, so that
* rs_close() knows when to free things. We restore it upon
* exit, either normal or abnormal.
*/
retval = 0;
add_wait_queue(&info->open_wait, &wait);
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready before block: ttys%d, count = %d\n",
state->line, state->count);
#endif
local_irq_save(flags);
if (!tty_hung_up_p(filp)) {
extra_count = 1;
state->count--;
}
local_irq_restore(flags);
info->blocked_open++;
while (1) {
local_irq_save(flags);
if (tty->termios->c_cflag & CBAUD)
rtsdtr_ctrl(SER_DTR|SER_RTS);
local_irq_restore(flags);
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(info->flags & ASYNC_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
if (info->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
#else
retval = -EAGAIN;
#endif
break;
}
if (!(info->flags & ASYNC_CLOSING) &&
(do_clocal || (!(ciab.pra & SER_DCD)) ))
break;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready blocking: ttys%d, count = %d\n",
info->line, state->count);
#endif
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
if (extra_count)
state->count++;
info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready after blocking: ttys%d, count = %d\n",
info->line, state->count);
#endif
if (retval)
return retval;
info->flags |= ASYNC_NORMAL_ACTIVE;
return 0;
}
static int get_async_struct(int line, struct async_struct **ret_info)
{
struct async_struct *info;
struct serial_state *sstate;
sstate = rs_table + line;
sstate->count++;
if (sstate->info) {
*ret_info = sstate->info;
return 0;
}
info = kmalloc(sizeof(struct async_struct), GFP_KERNEL);
if (!info) {
sstate->count--;
return -ENOMEM;
}
memset(info, 0, sizeof(struct async_struct));
#ifdef DECLARE_WAITQUEUE
init_waitqueue_head(&info->open_wait);
init_waitqueue_head(&info->close_wait);
init_waitqueue_head(&info->delta_msr_wait);
#endif
info->magic = SERIAL_MAGIC;
info->port = sstate->port;
info->flags = sstate->flags;
info->xmit_fifo_size = sstate->xmit_fifo_size;
info->line = line;
tasklet_init(&info->tlet, do_softint, (unsigned long)info);
info->state = sstate;
if (sstate->info) {
kfree(info);
*ret_info = sstate->info;
return 0;
}
*ret_info = sstate->info = info;
return 0;
}
/*
* This routine is called whenever a serial port is opened. It
* enables interrupts for a serial port, linking in its async structure into
* the IRQ chain. It also performs the serial-specific
* initialization for the tty structure.
*/
static int rs_open(struct tty_struct *tty, struct file * filp)
{
struct async_struct *info;
int retval, line;
unsigned long page;
line = tty->index;
if ((line < 0) || (line >= NR_PORTS)) {
return -ENODEV;
}
retval = get_async_struct(line, &info);
if (retval) {
return retval;
}
tty->driver_data = info;
info->tty = tty;
if (serial_paranoia_check(info, tty->name, "rs_open"))
return -ENODEV;
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open %s, count = %d\n", tty->name, info->state->count);
#endif
info->tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
if (!tmp_buf) {
page = get_zeroed_page(GFP_KERNEL);
if (!page) {
return -ENOMEM;
}
if (tmp_buf)
free_page(page);
else
tmp_buf = (unsigned char *) page;
}
/*
* If the port is the middle of closing, bail out now
*/
if (tty_hung_up_p(filp) ||
(info->flags & ASYNC_CLOSING)) {
if (info->flags & ASYNC_CLOSING)
interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
return ((info->flags & ASYNC_HUP_NOTIFY) ?
-EAGAIN : -ERESTARTSYS);
#else
return -EAGAIN;
#endif
}
/*
* Start up serial port
*/
retval = startup(info);
if (retval) {
return retval;
}
retval = block_til_ready(tty, filp, info);
if (retval) {
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open returning after block_til_ready with %d\n",
retval);
#endif
return retval;
}
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open %s successful...", tty->name);
#endif
return 0;
}
/*
* /proc fs routines....
*/
static inline int line_info(char *buf, struct serial_state *state)
{
struct async_struct *info = state->info, scr_info;
char stat_buf[30], control, status;
int ret;
unsigned long flags;
ret = sprintf(buf, "%d: uart:amiga_builtin",state->line);
/*
* Figure out the current RS-232 lines
*/
if (!info) {
info = &scr_info; /* This is just for serial_{in,out} */
info->magic = SERIAL_MAGIC;
info->flags = state->flags;
info->quot = 0;
info->tty = NULL;
}
local_irq_save(flags);
status = ciab.pra;
control = info ? info->MCR : status;
local_irq_restore(flags);
stat_buf[0] = 0;
stat_buf[1] = 0;
if(!(control & SER_RTS))
strcat(stat_buf, "|RTS");
if(!(status & SER_CTS))
strcat(stat_buf, "|CTS");
if(!(control & SER_DTR))
strcat(stat_buf, "|DTR");
if(!(status & SER_DSR))
strcat(stat_buf, "|DSR");
if(!(status & SER_DCD))
strcat(stat_buf, "|CD");
if (info->quot) {
ret += sprintf(buf+ret, " baud:%d",
state->baud_base / info->quot);
}
ret += sprintf(buf+ret, " tx:%d rx:%d",
state->icount.tx, state->icount.rx);
if (state->icount.frame)
ret += sprintf(buf+ret, " fe:%d", state->icount.frame);
if (state->icount.parity)
ret += sprintf(buf+ret, " pe:%d", state->icount.parity);
if (state->icount.brk)
ret += sprintf(buf+ret, " brk:%d", state->icount.brk);
if (state->icount.overrun)
ret += sprintf(buf+ret, " oe:%d", state->icount.overrun);
/*
* Last thing is the RS-232 status lines
*/
ret += sprintf(buf+ret, " %s\n", stat_buf+1);
return ret;
}
static int rs_read_proc(char *page, char **start, off_t off, int count,
int *eof, void *data)
{
int len = 0, l;
off_t begin = 0;
len += sprintf(page, "serinfo:1.0 driver:%s\n", serial_version);
l = line_info(page + len, &rs_table[0]);
len += l;
if (len+begin > off+count)
goto done;
if (len+begin < off) {
begin += len;
len = 0;
}
*eof = 1;
done:
if (off >= len+begin)
return 0;
*start = page + (off-begin);
return ((count < begin+len-off) ? count : begin+len-off);
}
/*
* ---------------------------------------------------------------------
* rs_init() and friends
*
* rs_init() is called at boot-time to initialize the serial driver.
* ---------------------------------------------------------------------
*/
/*
* This routine prints out the appropriate serial driver version
* number, and identifies which options were configured into this
* driver.
*/
static _INLINE_ void show_serial_version(void)
{
printk(KERN_INFO "%s version %s\n", serial_name, serial_version);
}
static struct tty_operations serial_ops = {
.open = rs_open,
.close = rs_close,
.write = rs_write,
.put_char = rs_put_char,
.flush_chars = rs_flush_chars,
.write_room = rs_write_room,
.chars_in_buffer = rs_chars_in_buffer,
.flush_buffer = rs_flush_buffer,
.ioctl = rs_ioctl,
.throttle = rs_throttle,
.unthrottle = rs_unthrottle,
.set_termios = rs_set_termios,
.stop = rs_stop,
.start = rs_start,
.hangup = rs_hangup,
.break_ctl = rs_break,
.send_xchar = rs_send_xchar,
.wait_until_sent = rs_wait_until_sent,
.read_proc = rs_read_proc,
.tiocmget = rs_tiocmget,
.tiocmset = rs_tiocmset,
};
/*
* The serial driver boot-time initialization code!
*/
static int __init rs_init(void)
{
unsigned long flags;
struct serial_state * state;
if (!MACH_IS_AMIGA || !AMIGAHW_PRESENT(AMI_SERIAL))
return -ENODEV;
serial_driver = alloc_tty_driver(1);
if (!serial_driver)
return -ENOMEM;
/*
* We request SERDAT and SERPER only, because the serial registers are
* too spreaded over the custom register space
*/
if (!request_mem_region(CUSTOM_PHYSADDR+0x30, 4, "amiserial [Paula]"))
return -EBUSY;
IRQ_ports = NULL;
show_serial_version();
/* Initialize the tty_driver structure */
serial_driver->owner = THIS_MODULE;
serial_driver->driver_name = "amiserial";
serial_driver->name = "ttyS";
serial_driver->major = TTY_MAJOR;
serial_driver->minor_start = 64;
serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
serial_driver->subtype = SERIAL_TYPE_NORMAL;
serial_driver->init_termios = tty_std_termios;
serial_driver->init_termios.c_cflag =
B9600 | CS8 | CREAD | HUPCL | CLOCAL;
serial_driver->flags = TTY_DRIVER_REAL_RAW;
tty_set_operations(serial_driver, &serial_ops);
if (tty_register_driver(serial_driver))
panic("Couldn't register serial driver\n");
state = rs_table;
state->magic = SSTATE_MAGIC;
state->port = (int)&custom.serdatr; /* Just to give it a value */
state->line = 0;
state->custom_divisor = 0;
state->close_delay = 5*HZ/10;
state->closing_wait = 30*HZ;
state->icount.cts = state->icount.dsr =
state->icount.rng = state->icount.dcd = 0;
state->icount.rx = state->icount.tx = 0;
state->icount.frame = state->icount.parity = 0;
state->icount.overrun = state->icount.brk = 0;
printk(KERN_INFO "ttyS%d is the amiga builtin serial port\n",
state->line);
/* Hardware set up */
state->baud_base = amiga_colorclock;
state->xmit_fifo_size = 1;
local_irq_save(flags);
/* set ISRs, and then disable the rx interrupts */
request_irq(IRQ_AMIGA_TBE, ser_tx_int, 0, "serial TX", state);
request_irq(IRQ_AMIGA_RBF, ser_rx_int, SA_INTERRUPT, "serial RX", state);
/* turn off Rx and Tx interrupts */
custom.intena = IF_RBF | IF_TBE;
mb();
/* clear any pending interrupt */
custom.intreq = IF_RBF | IF_TBE;
mb();
local_irq_restore(flags);
/*
* set the appropriate directions for the modem control flags,
* and clear RTS and DTR
*/
ciab.ddra |= (SER_DTR | SER_RTS); /* outputs */
ciab.ddra &= ~(SER_DCD | SER_CTS | SER_DSR); /* inputs */
return 0;
}
static __exit void rs_exit(void)
{
int error;
struct async_struct *info = rs_table[0].info;
/* printk("Unloading %s: version %s\n", serial_name, serial_version); */
tasklet_kill(&info->tlet);
if ((error = tty_unregister_driver(serial_driver)))
printk("SERIAL: failed to unregister serial driver (%d)\n",
error);
put_tty_driver(serial_driver);
if (info) {
rs_table[0].info = NULL;
kfree(info);
}
if (tmp_buf) {
free_page((unsigned long) tmp_buf);
tmp_buf = NULL;
}
release_mem_region(CUSTOM_PHYSADDR+0x30, 4);
}
module_init(rs_init)
module_exit(rs_exit)
/*
* ------------------------------------------------------------
* Serial console driver
* ------------------------------------------------------------
*/
#ifdef CONFIG_SERIAL_CONSOLE
static void amiga_serial_putc(char c)
{
custom.serdat = (unsigned char)c | 0x100;
while (!(custom.serdatr & 0x2000))
barrier();
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*
* The console must be locked when we get here.
*/
static void serial_console_write(struct console *co, const char *s,
unsigned count)
{
unsigned short intena = custom.intenar;
custom.intena = IF_TBE;
while (count--) {
if (*s == '\n')
amiga_serial_putc('\r');
amiga_serial_putc(*s++);
}
custom.intena = IF_SETCLR | (intena & IF_TBE);
}
static struct tty_driver *serial_console_device(struct console *c, int *index)
{
*index = 0;
return serial_driver;
}
static struct console sercons = {
.name = "ttyS",
.write = serial_console_write,
.device = serial_console_device,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/*
* Register console.
*/
static int __init amiserial_console_init(void)
{
register_console(&sercons);
return 0;
}
console_initcall(amiserial_console_init);
#endif
MODULE_LICENSE("GPL");
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