linux/drivers/tc/zs.c

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/*
* decserial.c: Serial port driver for IOASIC DECstations.
*
* Derived from drivers/sbus/char/sunserial.c by Paul Mackerras.
* Derived from drivers/macintosh/macserial.c by Harald Koerfgen.
*
* DECstation changes
* Copyright (C) 1998-2000 Harald Koerfgen
* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 Maciej W. Rozycki
*
* For the rest of the code the original Copyright applies:
* Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au)
* Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
*
*
* Note: for IOASIC systems the wiring is as follows:
*
* mouse/keyboard:
* DIN-7 MJ-4 signal SCC
* 2 1 TxD <- A.TxD
* 3 4 RxD -> A.RxD
*
* EIA-232/EIA-423:
* DB-25 MMJ-6 signal SCC
* 2 2 TxD <- B.TxD
* 3 5 RxD -> B.RxD
* 4 RTS <- ~A.RTS
* 5 CTS -> ~B.CTS
* 6 6 DSR -> ~A.SYNC
* 8 CD -> ~B.DCD
* 12 DSRS(DCE) -> ~A.CTS (*)
* 15 TxC -> B.TxC
* 17 RxC -> B.RxC
* 20 1 DTR <- ~A.DTR
* 22 RI -> ~A.DCD
* 23 DSRS(DTE) <- ~B.RTS
*
* (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE)
* is shared with DSRS(DTE) at pin 23.
*/
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#ifdef CONFIG_SERIAL_DEC_CONSOLE
#include <linux/console.h>
#endif
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/bootinfo.h>
#include <asm/dec/interrupts.h>
#include <asm/dec/ioasic_addrs.h>
#include <asm/dec/machtype.h>
#include <asm/dec/serial.h>
#include <asm/dec/system.h>
#ifdef CONFIG_KGDB
#include <asm/kgdb.h>
#endif
#ifdef CONFIG_MAGIC_SYSRQ
#include <linux/sysrq.h>
#endif
#include "zs.h"
/*
* It would be nice to dynamically allocate everything that
* depends on NUM_SERIAL, so we could support any number of
* Z8530s, but for now...
*/
#define NUM_SERIAL 2 /* Max number of ZS chips supported */
#define NUM_CHANNELS (NUM_SERIAL * 2) /* 2 channels per chip */
#define CHANNEL_A_NR (zs_parms->channel_a_offset > zs_parms->channel_b_offset)
/* Number of channel A in the chip */
#define ZS_CHAN_IO_SIZE 8
#define ZS_CLOCK 7372800 /* Z8530 RTxC input clock rate */
#define RECOVERY_DELAY udelay(2)
struct zs_parms {
unsigned long scc0;
unsigned long scc1;
int channel_a_offset;
int channel_b_offset;
int irq0;
int irq1;
int clock;
};
static struct zs_parms *zs_parms;
#ifdef CONFIG_MACH_DECSTATION
static struct zs_parms ds_parms = {
scc0 : IOASIC_SCC0,
scc1 : IOASIC_SCC1,
channel_a_offset : 1,
channel_b_offset : 9,
irq0 : -1,
irq1 : -1,
clock : ZS_CLOCK
};
#endif
#ifdef CONFIG_MACH_DECSTATION
#define DS_BUS_PRESENT (IOASIC)
#else
#define DS_BUS_PRESENT 0
#endif
#define BUS_PRESENT (DS_BUS_PRESENT)
DEFINE_SPINLOCK(zs_lock);
struct dec_zschannel zs_channels[NUM_CHANNELS];
struct dec_serial zs_soft[NUM_CHANNELS];
int zs_channels_found;
struct dec_serial *zs_chain; /* list of all channels */
struct tty_struct zs_ttys[NUM_CHANNELS];
#ifdef CONFIG_SERIAL_DEC_CONSOLE
static struct console sercons;
#endif
#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
!defined(MODULE)
static unsigned long break_pressed; /* break, really ... */
#endif
static unsigned char zs_init_regs[16] __initdata = {
0, /* write 0 */
0, /* write 1 */
0, /* write 2 */
0, /* write 3 */
(X16CLK), /* write 4 */
0, /* write 5 */
0, 0, 0, /* write 6, 7, 8 */
(MIE | DLC | NV), /* write 9 */
(NRZ), /* write 10 */
(TCBR | RCBR), /* write 11 */
0, 0, /* BRG time constant, write 12 + 13 */
(BRSRC | BRENABL), /* write 14 */
0 /* write 15 */
};
static struct tty_driver *serial_driver;
/* serial subtype definitions */
#define SERIAL_TYPE_NORMAL 1
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
/*
* Debugging.
*/
#undef SERIAL_DEBUG_OPEN
#undef SERIAL_DEBUG_FLOW
#undef SERIAL_DEBUG_THROTTLE
#undef SERIAL_PARANOIA_CHECK
#undef ZS_DEBUG_REGS
#ifdef SERIAL_DEBUG_THROTTLE
#define _tty_name(tty,buf) tty_name(tty,buf)
#endif
#define RS_STROBE_TIME 10
#define RS_ISR_PASS_LIMIT 256
static void probe_sccs(void);
static void change_speed(struct dec_serial *info);
static void rs_wait_until_sent(struct tty_struct *tty, int timeout);
static inline int serial_paranoia_check(struct dec_serial *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 mac_serial 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;
}
/*
* This is used to figure out the divisor speeds and the timeouts
*/
static int baud_table[] = {
0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
9600, 19200, 38400, 57600, 115200, 0 };
/*
* Reading and writing Z8530 registers.
*/
static inline unsigned char read_zsreg(struct dec_zschannel *channel,
unsigned char reg)
{
unsigned char retval;
if (reg != 0) {
*channel->control = reg & 0xf;
fast_iob(); RECOVERY_DELAY;
}
retval = *channel->control;
RECOVERY_DELAY;
return retval;
}
static inline void write_zsreg(struct dec_zschannel *channel,
unsigned char reg, unsigned char value)
{
if (reg != 0) {
*channel->control = reg & 0xf;
fast_iob(); RECOVERY_DELAY;
}
*channel->control = value;
fast_iob(); RECOVERY_DELAY;
return;
}
static inline unsigned char read_zsdata(struct dec_zschannel *channel)
{
unsigned char retval;
retval = *channel->data;
RECOVERY_DELAY;
return retval;
}
static inline void write_zsdata(struct dec_zschannel *channel,
unsigned char value)
{
*channel->data = value;
fast_iob(); RECOVERY_DELAY;
return;
}
static inline void load_zsregs(struct dec_zschannel *channel,
unsigned char *regs)
{
/* ZS_CLEARERR(channel);
ZS_CLEARFIFO(channel); */
/* Load 'em up */
write_zsreg(channel, R3, regs[R3] & ~RxENABLE);
write_zsreg(channel, R5, regs[R5] & ~TxENAB);
write_zsreg(channel, R4, regs[R4]);
write_zsreg(channel, R9, regs[R9]);
write_zsreg(channel, R1, regs[R1]);
write_zsreg(channel, R2, regs[R2]);
write_zsreg(channel, R10, regs[R10]);
write_zsreg(channel, R11, regs[R11]);
write_zsreg(channel, R12, regs[R12]);
write_zsreg(channel, R13, regs[R13]);
write_zsreg(channel, R14, regs[R14]);
write_zsreg(channel, R15, regs[R15]);
write_zsreg(channel, R3, regs[R3]);
write_zsreg(channel, R5, regs[R5]);
return;
}
/* Sets or clears DTR/RTS on the requested line */
static inline void zs_rtsdtr(struct dec_serial *info, int which, int set)
{
unsigned long flags;
spin_lock_irqsave(&zs_lock, flags);
if (info->zs_channel != info->zs_chan_a) {
if (set) {
info->zs_chan_a->curregs[5] |= (which & (RTS | DTR));
} else {
info->zs_chan_a->curregs[5] &= ~(which & (RTS | DTR));
}
write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
}
spin_unlock_irqrestore(&zs_lock, flags);
}
/* Utility routines for the Zilog */
static inline int get_zsbaud(struct dec_serial *ss)
{
struct dec_zschannel *channel = ss->zs_channel;
int brg;
/* The baud rate is split up between two 8-bit registers in
* what is termed 'BRG time constant' format in my docs for
* the chip, it is a function of the clk rate the chip is
* receiving which happens to be constant.
*/
brg = (read_zsreg(channel, 13) << 8);
brg |= read_zsreg(channel, 12);
return BRG_TO_BPS(brg, (zs_parms->clock/(ss->clk_divisor)));
}
/* On receive, this clears errors and the receiver interrupts */
static inline void rs_recv_clear(struct dec_zschannel *zsc)
{
write_zsreg(zsc, 0, ERR_RES);
write_zsreg(zsc, 0, RES_H_IUS); /* XXX this is unnecessary */
}
/*
* ----------------------------------------------------------------------
*
* 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.
*
* - 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 void rs_sched_event(struct dec_serial *info, int event)
{
info->event |= 1 << event;
tasklet_schedule(&info->tlet);
}
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static void receive_chars(struct dec_serial *info)
{
struct tty_struct *tty = info->tty;
unsigned char ch, stat, flag;
while ((read_zsreg(info->zs_channel, R0) & Rx_CH_AV) != 0) {
stat = read_zsreg(info->zs_channel, R1);
ch = read_zsdata(info->zs_channel);
if (!tty && (!info->hook || !info->hook->rx_char))
continue;
flag = TTY_NORMAL;
if (info->tty_break) {
info->tty_break = 0;
flag = TTY_BREAK;
if (info->flags & ZILOG_SAK)
do_SAK(tty);
/* Ignore the null char got when BREAK is removed. */
if (ch == 0)
continue;
} else {
if (stat & Rx_OVR) {
flag = TTY_OVERRUN;
} else if (stat & FRM_ERR) {
flag = TTY_FRAME;
} else if (stat & PAR_ERR) {
flag = TTY_PARITY;
}
if (flag != TTY_NORMAL)
/* reset the error indication */
write_zsreg(info->zs_channel, R0, ERR_RES);
}
#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
!defined(MODULE)
if (break_pressed && info->line == sercons.index) {
/* Ignore the null char got when BREAK is removed. */
if (ch == 0)
continue;
if (time_before(jiffies, break_pressed + HZ * 5)) {
handle_sysrq(ch, NULL);
break_pressed = 0;
continue;
}
break_pressed = 0;
}
#endif
if (info->hook && info->hook->rx_char) {
(*info->hook->rx_char)(ch, flag);
return;
}
tty_insert_flip_char(tty, ch, flag);
}
if (tty)
tty_flip_buffer_push(tty);
}
static void transmit_chars(struct dec_serial *info)
{
if ((read_zsreg(info->zs_channel, R0) & Tx_BUF_EMP) == 0)
return;
info->tx_active = 0;
if (info->x_char) {
/* Send next char */
write_zsdata(info->zs_channel, info->x_char);
info->x_char = 0;
info->tx_active = 1;
return;
}
if ((info->xmit_cnt <= 0) || (info->tty && info->tty->stopped)
|| info->tx_stopped) {
write_zsreg(info->zs_channel, R0, RES_Tx_P);
return;
}
/* Send char */
write_zsdata(info->zs_channel, info->xmit_buf[info->xmit_tail++]);
info->xmit_tail = info->xmit_tail & (SERIAL_XMIT_SIZE-1);
info->xmit_cnt--;
info->tx_active = 1;
if (info->xmit_cnt < WAKEUP_CHARS)
rs_sched_event(info, RS_EVENT_WRITE_WAKEUP);
}
static void status_handle(struct dec_serial *info)
{
unsigned char stat;
/* Get status from Read Register 0 */
stat = read_zsreg(info->zs_channel, R0);
if ((stat & BRK_ABRT) && !(info->read_reg_zero & BRK_ABRT)) {
#if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \
!defined(MODULE)
if (info->line == sercons.index) {
if (!break_pressed)
break_pressed = jiffies;
} else
#endif
info->tty_break = 1;
}
if (info->zs_channel != info->zs_chan_a) {
/* Check for DCD transitions */
if (info->tty && !C_CLOCAL(info->tty) &&
((stat ^ info->read_reg_zero) & DCD) != 0 ) {
if (stat & DCD) {
wake_up_interruptible(&info->open_wait);
} else {
tty_hangup(info->tty);
}
}
/* Check for CTS transitions */
if (info->tty && C_CRTSCTS(info->tty)) {
if ((stat & CTS) != 0) {
if (info->tx_stopped) {
info->tx_stopped = 0;
if (!info->tx_active)
transmit_chars(info);
}
} else {
info->tx_stopped = 1;
}
}
}
/* Clear status condition... */
write_zsreg(info->zs_channel, R0, RES_EXT_INT);
info->read_reg_zero = stat;
}
/*
* This is the serial driver's generic interrupt routine
*/
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
static irqreturn_t rs_interrupt(int irq, void *dev_id)
{
struct dec_serial *info = (struct dec_serial *) dev_id;
irqreturn_t status = IRQ_NONE;
unsigned char zs_intreg;
int shift;
/* NOTE: The read register 3, which holds the irq status,
* does so for both channels on each chip. Although
* the status value itself must be read from the A
* channel and is only valid when read from channel A.
* Yes... broken hardware...
*/
#define CHAN_IRQMASK (CHBRxIP | CHBTxIP | CHBEXT)
if (info->zs_chan_a == info->zs_channel)
shift = 3; /* Channel A */
else
shift = 0; /* Channel B */
for (;;) {
zs_intreg = read_zsreg(info->zs_chan_a, R3) >> shift;
if ((zs_intreg & CHAN_IRQMASK) == 0)
break;
status = IRQ_HANDLED;
if (zs_intreg & CHBRxIP) {
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 13:55:46 +00:00
receive_chars(info);
}
if (zs_intreg & CHBTxIP) {
transmit_chars(info);
}
if (zs_intreg & CHBEXT) {
status_handle(info);
}
}
/* Why do we need this ? */
write_zsreg(info->zs_channel, 0, RES_H_IUS);
return status;
}
#ifdef ZS_DEBUG_REGS
void zs_dump (void) {
int i, j;
for (i = 0; i < zs_channels_found; i++) {
struct dec_zschannel *ch = &zs_channels[i];
if ((long)ch->control == UNI_IO_BASE+UNI_SCC1A_CTRL) {
for (j = 0; j < 15; j++) {
printk("W%d = 0x%x\t",
j, (int)ch->curregs[j]);
}
for (j = 0; j < 15; j++) {
printk("R%d = 0x%x\t",
j, (int)read_zsreg(ch,j));
}
printk("\n\n");
}
}
}
#endif
/*
* -------------------------------------------------------------------
* Here ends the serial interrupt routines.
* -------------------------------------------------------------------
*/
/*
* ------------------------------------------------------------
* rs_stop() and rs_start()
*
* This routines are called before setting or resetting tty->stopped.
* ------------------------------------------------------------
*/
static void rs_stop(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_stop"))
return;
#if 1
spin_lock_irqsave(&zs_lock, flags);
if (info->zs_channel->curregs[5] & TxENAB) {
info->zs_channel->curregs[5] &= ~TxENAB;
write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
}
spin_unlock_irqrestore(&zs_lock, flags);
#endif
}
static void rs_start(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_start"))
return;
spin_lock_irqsave(&zs_lock, flags);
#if 1
if (info->xmit_cnt && info->xmit_buf && !(info->zs_channel->curregs[5] & TxENAB)) {
info->zs_channel->curregs[5] |= TxENAB;
write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
}
#else
if (info->xmit_cnt && info->xmit_buf && !info->tx_active) {
transmit_chars(info);
}
#endif
spin_unlock_irqrestore(&zs_lock, flags);
}
/*
* 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 dec_serial *info = (struct dec_serial *) 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);
}
static int zs_startup(struct dec_serial * info)
{
unsigned long flags;
if (info->flags & ZILOG_INITIALIZED)
return 0;
if (!info->xmit_buf) {
info->xmit_buf = (unsigned char *) get_zeroed_page(GFP_KERNEL);
if (!info->xmit_buf)
return -ENOMEM;
}
spin_lock_irqsave(&zs_lock, flags);
#ifdef SERIAL_DEBUG_OPEN
printk("starting up ttyS%d (irq %d)...", info->line, info->irq);
#endif
/*
* Clear the receive FIFO.
*/
ZS_CLEARFIFO(info->zs_channel);
info->xmit_fifo_size = 1;
/*
* Clear the interrupt registers.
*/
write_zsreg(info->zs_channel, R0, ERR_RES);
write_zsreg(info->zs_channel, R0, RES_H_IUS);
/*
* Set the speed of the serial port
*/
change_speed(info);
/*
* Turn on RTS and DTR.
*/
zs_rtsdtr(info, RTS | DTR, 1);
/*
* Finally, enable sequencing and interrupts
*/
info->zs_channel->curregs[R1] &= ~RxINT_MASK;
info->zs_channel->curregs[R1] |= (RxINT_ALL | TxINT_ENAB |
EXT_INT_ENAB);
info->zs_channel->curregs[R3] |= RxENABLE;
info->zs_channel->curregs[R5] |= TxENAB;
info->zs_channel->curregs[R15] |= (DCDIE | CTSIE | TxUIE | BRKIE);
write_zsreg(info->zs_channel, R1, info->zs_channel->curregs[R1]);
write_zsreg(info->zs_channel, R3, info->zs_channel->curregs[R3]);
write_zsreg(info->zs_channel, R5, info->zs_channel->curregs[R5]);
write_zsreg(info->zs_channel, R15, info->zs_channel->curregs[R15]);
/*
* And clear the interrupt registers again for luck.
*/
write_zsreg(info->zs_channel, R0, ERR_RES);
write_zsreg(info->zs_channel, R0, RES_H_IUS);
/* Save the current value of RR0 */
info->read_reg_zero = read_zsreg(info->zs_channel, R0);
if (info->tty)
clear_bit(TTY_IO_ERROR, &info->tty->flags);
info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
info->flags |= ZILOG_INITIALIZED;
spin_unlock_irqrestore(&zs_lock, flags);
return 0;
}
/*
* 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 dec_serial * info)
{
unsigned long flags;
if (!(info->flags & ZILOG_INITIALIZED))
return;
#ifdef SERIAL_DEBUG_OPEN
printk("Shutting down serial port %d (irq %d)....", info->line,
info->irq);
#endif
spin_lock_irqsave(&zs_lock, flags);
if (info->xmit_buf) {
free_page((unsigned long) info->xmit_buf);
info->xmit_buf = 0;
}
info->zs_channel->curregs[1] = 0;
write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]); /* no interrupts */
info->zs_channel->curregs[3] &= ~RxENABLE;
write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
info->zs_channel->curregs[5] &= ~TxENAB;
write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
if (!info->tty || C_HUPCL(info->tty)) {
zs_rtsdtr(info, RTS | DTR, 0);
}
if (info->tty)
set_bit(TTY_IO_ERROR, &info->tty->flags);
info->flags &= ~ZILOG_INITIALIZED;
spin_unlock_irqrestore(&zs_lock, 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 dec_serial *info)
{
unsigned cflag;
int i;
int brg, bits;
unsigned long flags;
if (!info->hook) {
if (!info->tty || !info->tty->termios)
return;
cflag = info->tty->termios->c_cflag;
if (!info->port)
return;
} else {
cflag = info->hook->cflags;
}
i = cflag & CBAUD;
if (i & CBAUDEX) {
i &= ~CBAUDEX;
if (i < 1 || i > 2) {
if (!info->hook)
info->tty->termios->c_cflag &= ~CBAUDEX;
else
info->hook->cflags &= ~CBAUDEX;
} else
i += 15;
}
spin_lock_irqsave(&zs_lock, flags);
info->zs_baud = baud_table[i];
if (info->zs_baud) {
brg = BPS_TO_BRG(info->zs_baud, zs_parms->clock/info->clk_divisor);
info->zs_channel->curregs[12] = (brg & 255);
info->zs_channel->curregs[13] = ((brg >> 8) & 255);
zs_rtsdtr(info, DTR, 1);
} else {
zs_rtsdtr(info, RTS | DTR, 0);
return;
}
/* byte size and parity */
info->zs_channel->curregs[3] &= ~RxNBITS_MASK;
info->zs_channel->curregs[5] &= ~TxNBITS_MASK;
switch (cflag & CSIZE) {
case CS5:
bits = 7;
info->zs_channel->curregs[3] |= Rx5;
info->zs_channel->curregs[5] |= Tx5;
break;
case CS6:
bits = 8;
info->zs_channel->curregs[3] |= Rx6;
info->zs_channel->curregs[5] |= Tx6;
break;
case CS7:
bits = 9;
info->zs_channel->curregs[3] |= Rx7;
info->zs_channel->curregs[5] |= Tx7;
break;
case CS8:
default: /* defaults to 8 bits */
bits = 10;
info->zs_channel->curregs[3] |= Rx8;
info->zs_channel->curregs[5] |= Tx8;
break;
}
info->timeout = ((info->xmit_fifo_size*HZ*bits) / info->zs_baud);
info->timeout += HZ/50; /* Add .02 seconds of slop */
info->zs_channel->curregs[4] &= ~(SB_MASK | PAR_ENA | PAR_EVEN);
if (cflag & CSTOPB) {
info->zs_channel->curregs[4] |= SB2;
} else {
info->zs_channel->curregs[4] |= SB1;
}
if (cflag & PARENB) {
info->zs_channel->curregs[4] |= PAR_ENA;
}
if (!(cflag & PARODD)) {
info->zs_channel->curregs[4] |= PAR_EVEN;
}
if (!(cflag & CLOCAL)) {
if (!(info->zs_channel->curregs[15] & DCDIE))
info->read_reg_zero = read_zsreg(info->zs_channel, 0);
info->zs_channel->curregs[15] |= DCDIE;
} else
info->zs_channel->curregs[15] &= ~DCDIE;
if (cflag & CRTSCTS) {
info->zs_channel->curregs[15] |= CTSIE;
if ((read_zsreg(info->zs_channel, 0) & CTS) == 0)
info->tx_stopped = 1;
} else {
info->zs_channel->curregs[15] &= ~CTSIE;
info->tx_stopped = 0;
}
/* Load up the new values */
load_zsregs(info->zs_channel, info->zs_channel->curregs);
spin_unlock_irqrestore(&zs_lock, flags);
}
static void rs_flush_chars(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_flush_chars"))
return;
if (info->xmit_cnt <= 0 || tty->stopped || info->tx_stopped ||
!info->xmit_buf)
return;
/* Enable transmitter */
spin_lock_irqsave(&zs_lock, flags);
transmit_chars(info);
spin_unlock_irqrestore(&zs_lock, flags);
}
static int rs_write(struct tty_struct * tty,
const unsigned char *buf, int count)
{
int c, total = 0;
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_write"))
return 0;
if (!tty || !info->xmit_buf)
return 0;
while (1) {
spin_lock_irqsave(&zs_lock, flags);
c = min(count, min(SERIAL_XMIT_SIZE - info->xmit_cnt - 1,
SERIAL_XMIT_SIZE - info->xmit_head));
if (c <= 0)
break;
memcpy(info->xmit_buf + info->xmit_head, buf, c);
info->xmit_head = (info->xmit_head + c) & (SERIAL_XMIT_SIZE-1);
info->xmit_cnt += c;
spin_unlock_irqrestore(&zs_lock, flags);
buf += c;
count -= c;
total += c;
}
if (info->xmit_cnt && !tty->stopped && !info->tx_stopped
&& !info->tx_active)
transmit_chars(info);
spin_unlock_irqrestore(&zs_lock, flags);
return total;
}
static int rs_write_room(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
int ret;
if (serial_paranoia_check(info, tty->name, "rs_write_room"))
return 0;
ret = SERIAL_XMIT_SIZE - info->xmit_cnt - 1;
if (ret < 0)
ret = 0;
return ret;
}
static int rs_chars_in_buffer(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_chars_in_buffer"))
return 0;
return info->xmit_cnt;
}
static void rs_flush_buffer(struct tty_struct *tty)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_flush_buffer"))
return;
spin_lock_irq(&zs_lock);
info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
spin_unlock_irq(&zs_lock);
tty_wakeup(tty);
}
/*
* ------------------------------------------------------------
* 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 dec_serial *info = (struct dec_serial *)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)) {
spin_lock_irqsave(&zs_lock, flags);
info->x_char = STOP_CHAR(tty);
if (!info->tx_active)
transmit_chars(info);
spin_unlock_irqrestore(&zs_lock, flags);
}
if (C_CRTSCTS(tty)) {
zs_rtsdtr(info, RTS, 0);
}
}
static void rs_unthrottle(struct tty_struct * tty)
{
struct dec_serial *info = (struct dec_serial *)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)) {
spin_lock_irqsave(&zs_lock, flags);
if (info->x_char)
info->x_char = 0;
else {
info->x_char = START_CHAR(tty);
if (!info->tx_active)
transmit_chars(info);
}
spin_unlock_irqrestore(&zs_lock, flags);
}
if (C_CRTSCTS(tty)) {
zs_rtsdtr(info, RTS, 1);
}
}
/*
* ------------------------------------------------------------
* rs_ioctl() and friends
* ------------------------------------------------------------
*/
static int get_serial_info(struct dec_serial * info,
struct serial_struct * retinfo)
{
struct serial_struct tmp;
if (!retinfo)
return -EFAULT;
memset(&tmp, 0, sizeof(tmp));
tmp.type = info->type;
tmp.line = info->line;
tmp.port = info->port;
tmp.irq = info->irq;
tmp.flags = info->flags;
tmp.baud_base = info->baud_base;
tmp.close_delay = info->close_delay;
tmp.closing_wait = info->closing_wait;
tmp.custom_divisor = info->custom_divisor;
return copy_to_user(retinfo,&tmp,sizeof(*retinfo)) ? -EFAULT : 0;
}
static int set_serial_info(struct dec_serial * info,
struct serial_struct * new_info)
{
struct serial_struct new_serial;
struct dec_serial old_info;
int retval = 0;
if (!new_info)
return -EFAULT;
copy_from_user(&new_serial,new_info,sizeof(new_serial));
old_info = *info;
if (!capable(CAP_SYS_ADMIN)) {
if ((new_serial.baud_base != info->baud_base) ||
(new_serial.type != info->type) ||
(new_serial.close_delay != info->close_delay) ||
((new_serial.flags & ~ZILOG_USR_MASK) !=
(info->flags & ~ZILOG_USR_MASK)))
return -EPERM;
info->flags = ((info->flags & ~ZILOG_USR_MASK) |
(new_serial.flags & ZILOG_USR_MASK));
info->custom_divisor = new_serial.custom_divisor;
goto check_and_exit;
}
if (info->count > 1)
return -EBUSY;
/*
* OK, past this point, all the error checking has been done.
* At this point, we start making changes.....
*/
info->baud_base = new_serial.baud_base;
info->flags = ((info->flags & ~ZILOG_FLAGS) |
(new_serial.flags & ZILOG_FLAGS));
info->type = new_serial.type;
info->close_delay = new_serial.close_delay;
info->closing_wait = new_serial.closing_wait;
check_and_exit:
retval = zs_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 dec_serial * info, unsigned int *value)
{
unsigned char status;
spin_lock(&zs_lock);
status = read_zsreg(info->zs_channel, 0);
spin_unlock_irq(&zs_lock);
put_user(status,value);
return 0;
}
static int rs_tiocmget(struct tty_struct *tty, struct file *file)
{
struct dec_serial * info = (struct dec_serial *)tty->driver_data;
unsigned char control, status_a, status_b;
unsigned int result;
if (info->hook)
return -ENODEV;
if (serial_paranoia_check(info, tty->name, __FUNCTION__))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
if (info->zs_channel == info->zs_chan_a)
result = 0;
else {
spin_lock(&zs_lock);
control = info->zs_chan_a->curregs[5];
status_a = read_zsreg(info->zs_chan_a, 0);
status_b = read_zsreg(info->zs_channel, 0);
spin_unlock_irq(&zs_lock);
result = ((control & RTS) ? TIOCM_RTS: 0)
| ((control & DTR) ? TIOCM_DTR: 0)
| ((status_b & DCD) ? TIOCM_CAR: 0)
| ((status_a & DCD) ? TIOCM_RNG: 0)
| ((status_a & SYNC_HUNT) ? TIOCM_DSR: 0)
| ((status_b & CTS) ? TIOCM_CTS: 0);
}
return result;
}
static int rs_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
struct dec_serial * info = (struct dec_serial *)tty->driver_data;
if (info->hook)
return -ENODEV;
if (serial_paranoia_check(info, tty->name, __FUNCTION__))
return -ENODEV;
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
if (info->zs_channel == info->zs_chan_a)
return 0;
spin_lock(&zs_lock);
if (set & TIOCM_RTS)
info->zs_chan_a->curregs[5] |= RTS;
if (set & TIOCM_DTR)
info->zs_chan_a->curregs[5] |= DTR;
if (clear & TIOCM_RTS)
info->zs_chan_a->curregs[5] &= ~RTS;
if (clear & TIOCM_DTR)
info->zs_chan_a->curregs[5] &= ~DTR;
write_zsreg(info->zs_chan_a, 5, info->zs_chan_a->curregs[5]);
spin_unlock_irq(&zs_lock);
return 0;
}
/*
* rs_break - turn transmit break condition on/off
*/
static void rs_break(struct tty_struct *tty, int break_state)
{
struct dec_serial *info = (struct dec_serial *) tty->driver_data;
unsigned long flags;
if (serial_paranoia_check(info, tty->name, "rs_break"))
return;
if (!info->port)
return;
spin_lock_irqsave(&zs_lock, flags);
if (break_state == -1)
info->zs_channel->curregs[5] |= SND_BRK;
else
info->zs_channel->curregs[5] &= ~SND_BRK;
write_zsreg(info->zs_channel, 5, info->zs_channel->curregs[5]);
spin_unlock_irqrestore(&zs_lock, flags);
}
static int rs_ioctl(struct tty_struct *tty, struct file * file,
unsigned int cmd, unsigned long arg)
{
struct dec_serial * info = (struct dec_serial *)tty->driver_data;
if (info->hook)
return -ENODEV;
if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
return -ENODEV;
if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
(cmd != TIOCSERCONFIG) && (cmd != TIOCSERGWILD) &&
(cmd != TIOCSERSWILD) && (cmd != TIOCSERGSTRUCT)) {
if (tty->flags & (1 << TTY_IO_ERROR))
return -EIO;
}
switch (cmd) {
case TIOCGSERIAL:
if (!access_ok(VERIFY_WRITE, (void *)arg,
sizeof(struct serial_struct)))
return -EFAULT;
return get_serial_info(info, (struct serial_struct *)arg);
case TIOCSSERIAL:
return set_serial_info(info, (struct serial_struct *)arg);
case TIOCSERGETLSR: /* Get line status register */
if (!access_ok(VERIFY_WRITE, (void *)arg,
sizeof(unsigned int)))
return -EFAULT;
return get_lsr_info(info, (unsigned int *)arg);
case TIOCSERGSTRUCT:
if (!access_ok(VERIFY_WRITE, (void *)arg,
sizeof(struct dec_serial)))
return -EFAULT;
copy_from_user((struct dec_serial *)arg, info,
sizeof(struct dec_serial));
return 0;
default:
return -ENOIOCTLCMD;
}
return 0;
}
static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
{
struct dec_serial *info = (struct dec_serial *)tty->driver_data;
int was_stopped;
if (tty->termios->c_cflag == old_termios->c_cflag)
return;
was_stopped = info->tx_stopped;
change_speed(info);
if (was_stopped && !info->tx_stopped)
rs_start(tty);
}
/*
* ------------------------------------------------------------
* rs_close()
*
* This routine is called when the serial port gets closed.
* Wait for the last remaining data to be sent.
* ------------------------------------------------------------
*/
static void rs_close(struct tty_struct *tty, struct file * filp)
{
struct dec_serial * info = (struct dec_serial *)tty->driver_data;
unsigned long flags;
if (!info || serial_paranoia_check(info, tty->name, "rs_close"))
return;
spin_lock_irqsave(&zs_lock, flags);
if (tty_hung_up_p(filp)) {
spin_unlock_irqrestore(&zs_lock, flags);
return;
}
#ifdef SERIAL_DEBUG_OPEN
printk("rs_close ttyS%d, count = %d\n", info->line, info->count);
#endif
if ((tty->count == 1) && (info->count != 1)) {
/*
* Uh, oh. tty->count is 1, which means that the tty
* structure will be freed. Info->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, "
"info->count is %d\n", info->count);
info->count = 1;
}
if (--info->count < 0) {
printk("rs_close: bad serial port count for ttyS%d: %d\n",
info->line, info->count);
info->count = 0;
}
if (info->count) {
spin_unlock_irqrestore(&zs_lock, flags);
return;
}
info->flags |= ZILOG_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 != ZILOG_CLOSING_WAIT_NONE)
tty_wait_until_sent(tty, info->closing_wait);
/*
* At this point we stop accepting input. To do this, we
* disable the receiver and receive interrupts.
*/
info->zs_channel->curregs[3] &= ~RxENABLE;
write_zsreg(info->zs_channel, 3, info->zs_channel->curregs[3]);
info->zs_channel->curregs[1] = 0; /* disable any rx ints */
write_zsreg(info->zs_channel, 1, info->zs_channel->curregs[1]);
ZS_CLEARFIFO(info->zs_channel);
if (info->flags & ZILOG_INITIALIZED) {
/*
* Before we drop DTR, make sure the SCC transmitter
* has completely drained.
*/
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 = 0;
if (info->blocked_open) {
if (info->close_delay) {
msleep_interruptible(jiffies_to_msecs(info->close_delay));
}
wake_up_interruptible(&info->open_wait);
}
info->flags &= ~(ZILOG_NORMAL_ACTIVE|ZILOG_CLOSING);
wake_up_interruptible(&info->close_wait);
spin_unlock_irqrestore(&zs_lock, flags);
}
/*
* rs_wait_until_sent() --- wait until the transmitter is empty
*/
static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
{
struct dec_serial *info = (struct dec_serial *) tty->driver_data;
unsigned long orig_jiffies;
int char_time;
if (serial_paranoia_check(info, tty->name, "rs_wait_until_sent"))
return;
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.
*/
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(char_time, timeout);
while ((read_zsreg(info->zs_channel, 1) & Tx_BUF_EMP) == 0) {
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;
}
/*
* rs_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
static void rs_hangup(struct tty_struct *tty)
{
struct dec_serial * info = (struct dec_serial *)tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_hangup"))
return;
rs_flush_buffer(tty);
shutdown(info);
info->event = 0;
info->count = 0;
info->flags &= ~ZILOG_NORMAL_ACTIVE;
info->tty = 0;
wake_up_interruptible(&info->open_wait);
}
/*
* ------------------------------------------------------------
* rs_open() and friends
* ------------------------------------------------------------
*/
static int block_til_ready(struct tty_struct *tty, struct file * filp,
struct dec_serial *info)
{
DECLARE_WAITQUEUE(wait, current);
int retval;
int do_clocal = 0;
/*
* If the device is in the middle of being closed, then block
* until it's done, and then try again.
*/
if (info->flags & ZILOG_CLOSING) {
interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
return ((info->flags & ZILOG_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 |= ZILOG_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, info->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",
info->line, info->count);
#endif
spin_lock(&zs_lock);
if (!tty_hung_up_p(filp))
info->count--;
spin_unlock_irq(&zs_lock);
info->blocked_open++;
while (1) {
spin_lock(&zs_lock);
if (tty->termios->c_cflag & CBAUD)
zs_rtsdtr(info, RTS | DTR, 1);
spin_unlock_irq(&zs_lock);
set_current_state(TASK_INTERRUPTIBLE);
if (tty_hung_up_p(filp) ||
!(info->flags & ZILOG_INITIALIZED)) {
#ifdef SERIAL_DO_RESTART
if (info->flags & ZILOG_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
#else
retval = -EAGAIN;
#endif
break;
}
if (!(info->flags & ZILOG_CLOSING) &&
(do_clocal || (read_zsreg(info->zs_channel, 0) & 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, info->count);
#endif
schedule();
}
current->state = TASK_RUNNING;
remove_wait_queue(&info->open_wait, &wait);
if (!tty_hung_up_p(filp))
info->count++;
info->blocked_open--;
#ifdef SERIAL_DEBUG_OPEN
printk("block_til_ready after blocking: ttyS%d, count = %d\n",
info->line, info->count);
#endif
if (retval)
return retval;
info->flags |= ZILOG_NORMAL_ACTIVE;
return 0;
}
/*
* This routine is called whenever a serial port is opened. It
* enables interrupts for a serial port, linking in its ZILOG 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 dec_serial *info;
int retval, line;
line = tty->index;
if ((line < 0) || (line >= zs_channels_found))
return -ENODEV;
info = zs_soft + line;
if (info->hook)
return -ENODEV;
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->count);
#endif
info->count++;
tty->driver_data = info;
info->tty = tty;
/*
* If the port is the middle of closing, bail out now
*/
if (tty_hung_up_p(filp) ||
(info->flags & ZILOG_CLOSING)) {
if (info->flags & ZILOG_CLOSING)
interruptible_sleep_on(&info->close_wait);
#ifdef SERIAL_DO_RESTART
return ((info->flags & ZILOG_HUP_NOTIFY) ?
-EAGAIN : -ERESTARTSYS);
#else
return -EAGAIN;
#endif
}
/*
* Start up serial port
*/
retval = zs_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 CONFIG_SERIAL_DEC_CONSOLE
if (sercons.cflag && sercons.index == line) {
tty->termios->c_cflag = sercons.cflag;
sercons.cflag = 0;
change_speed(info);
}
#endif
#ifdef SERIAL_DEBUG_OPEN
printk("rs_open %s successful...", tty->name);
#endif
/* tty->low_latency = 1; */
return 0;
}
/* Finally, routines used to initialize the serial driver. */
static void __init show_serial_version(void)
{
printk("DECstation Z8530 serial driver version 0.09\n");
}
/* Initialize Z8530s zs_channels
*/
static void __init probe_sccs(void)
{
struct dec_serial **pp;
int i, n, n_chips = 0, n_channels, chip, channel;
unsigned long flags;
/*
* did we get here by accident?
*/
if(!BUS_PRESENT) {
printk("Not on JUNKIO machine, skipping probe_sccs\n");
return;
}
switch(mips_machtype) {
#ifdef CONFIG_MACH_DECSTATION
case MACH_DS5000_2X0:
case MACH_DS5900:
n_chips = 2;
zs_parms = &ds_parms;
zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
break;
case MACH_DS5000_1XX:
n_chips = 2;
zs_parms = &ds_parms;
zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
zs_parms->irq1 = dec_interrupt[DEC_IRQ_SCC1];
break;
case MACH_DS5000_XX:
n_chips = 1;
zs_parms = &ds_parms;
zs_parms->irq0 = dec_interrupt[DEC_IRQ_SCC0];
break;
#endif
default:
panic("zs: unsupported bus");
}
if (!zs_parms)
panic("zs: uninitialized parms");
pp = &zs_chain;
n_channels = 0;
for (chip = 0; chip < n_chips; chip++) {
for (channel = 0; channel <= 1; channel++) {
/*
* The sccs reside on the high byte of the 16 bit IOBUS
*/
zs_channels[n_channels].control =
(volatile void *)CKSEG1ADDR(dec_kn_slot_base +
(0 == chip ? zs_parms->scc0 : zs_parms->scc1) +
(0 == channel ? zs_parms->channel_a_offset :
zs_parms->channel_b_offset));
zs_channels[n_channels].data =
zs_channels[n_channels].control + 4;
#ifndef CONFIG_SERIAL_DEC_CONSOLE
/*
* We're called early and memory managment isn't up, yet.
* Thus request_region would fail.
*/
if (!request_region((unsigned long)
zs_channels[n_channels].control,
ZS_CHAN_IO_SIZE, "SCC"))
panic("SCC I/O region is not free");
#endif
zs_soft[n_channels].zs_channel = &zs_channels[n_channels];
/* HACK alert! */
if (!(chip & 1))
zs_soft[n_channels].irq = zs_parms->irq0;
else
zs_soft[n_channels].irq = zs_parms->irq1;
/*
* Identification of channel A. Location of channel A
* inside chip depends on mapping of internal address
* the chip decodes channels by.
* CHANNEL_A_NR returns either 0 (in case of
* DECstations) or 1 (in case of Baget).
*/
if (CHANNEL_A_NR == channel)
zs_soft[n_channels].zs_chan_a =
&zs_channels[n_channels+1-2*CHANNEL_A_NR];
else
zs_soft[n_channels].zs_chan_a =
&zs_channels[n_channels];
*pp = &zs_soft[n_channels];
pp = &zs_soft[n_channels].zs_next;
n_channels++;
}
}
*pp = 0;
zs_channels_found = n_channels;
for (n = 0; n < zs_channels_found; n++) {
for (i = 0; i < 16; i++) {
zs_soft[n].zs_channel->curregs[i] = zs_init_regs[i];
}
}
spin_lock_irqsave(&zs_lock, flags);
for (n = 0; n < zs_channels_found; n++) {
if (n % 2 == 0) {
write_zsreg(zs_soft[n].zs_chan_a, R9, FHWRES);
udelay(10);
write_zsreg(zs_soft[n].zs_chan_a, R9, 0);
}
load_zsregs(zs_soft[n].zs_channel,
zs_soft[n].zs_channel->curregs);
}
spin_unlock_irqrestore(&zs_lock, flags);
}
static const struct tty_operations serial_ops = {
.open = rs_open,
.close = rs_close,
.write = rs_write,
.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,
.wait_until_sent = rs_wait_until_sent,
.tiocmget = rs_tiocmget,
.tiocmset = rs_tiocmset,
};
/* zs_init inits the driver */
int __init zs_init(void)
{
int channel, i;
struct dec_serial *info;
if(!BUS_PRESENT)
return -ENODEV;
/* Find out how many Z8530 SCCs we have */
if (zs_chain == 0)
probe_sccs();
serial_driver = alloc_tty_driver(zs_channels_found);
if (!serial_driver)
return -ENOMEM;
show_serial_version();
/* Initialize the tty_driver structure */
/* Not all of this is exactly right for us. */
serial_driver->owner = THIS_MODULE;
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_DRIVER_DYNAMIC_DEV;
tty_set_operations(serial_driver, &serial_ops);
if (tty_register_driver(serial_driver))
panic("Couldn't register serial driver");
for (info = zs_chain, i = 0; info; info = info->zs_next, i++) {
/* Needed before interrupts are enabled. */
info->tty = 0;
info->x_char = 0;
if (info->hook && info->hook->init_info) {
(*info->hook->init_info)(info);
continue;
}
info->magic = SERIAL_MAGIC;
info->port = (int) info->zs_channel->control;
info->line = i;
info->custom_divisor = 16;
info->close_delay = 50;
info->closing_wait = 3000;
info->event = 0;
info->count = 0;
info->blocked_open = 0;
tasklet_init(&info->tlet, do_softint, (unsigned long)info);
init_waitqueue_head(&info->open_wait);
init_waitqueue_head(&info->close_wait);
printk("ttyS%02d at 0x%08x (irq = %d) is a Z85C30 SCC\n",
info->line, info->port, info->irq);
tty_register_device(serial_driver, info->line, NULL);
}
for (channel = 0; channel < zs_channels_found; ++channel) {
zs_soft[channel].clk_divisor = 16;
zs_soft[channel].zs_baud = get_zsbaud(&zs_soft[channel]);
if (request_irq(zs_soft[channel].irq, rs_interrupt, IRQF_SHARED,
"scc", &zs_soft[channel]))
printk(KERN_ERR "decserial: can't get irq %d\n",
zs_soft[channel].irq);
if (zs_soft[channel].hook) {
zs_startup(&zs_soft[channel]);
if (zs_soft[channel].hook->init_channel)
(*zs_soft[channel].hook->init_channel)
(&zs_soft[channel]);
}
}
return 0;
}
/*
* polling I/O routines
*/
static int zs_poll_tx_char(void *handle, unsigned char ch)
{
struct dec_serial *info = handle;
struct dec_zschannel *chan = info->zs_channel;
int ret;
if(chan) {
int loops = 10000;
while (loops && !(read_zsreg(chan, 0) & Tx_BUF_EMP))
loops--;
if (loops) {
write_zsdata(chan, ch);
ret = 0;
} else
ret = -EAGAIN;
return ret;
} else
return -ENODEV;
}
static int zs_poll_rx_char(void *handle)
{
struct dec_serial *info = handle;
struct dec_zschannel *chan = info->zs_channel;
int ret;
if(chan) {
int loops = 10000;
while (loops && !(read_zsreg(chan, 0) & Rx_CH_AV))
loops--;
if (loops)
ret = read_zsdata(chan);
else
ret = -EAGAIN;
return ret;
} else
return -ENODEV;
}
int register_zs_hook(unsigned int channel, struct dec_serial_hook *hook)
{
struct dec_serial *info = &zs_soft[channel];
if (info->hook) {
printk("%s: line %d has already a hook registered\n",
__FUNCTION__, channel);
return 0;
} else {
hook->poll_rx_char = zs_poll_rx_char;
hook->poll_tx_char = zs_poll_tx_char;
info->hook = hook;
return 1;
}
}
int unregister_zs_hook(unsigned int channel)
{
struct dec_serial *info = &zs_soft[channel];
if (info->hook) {
info->hook = NULL;
return 1;
} else {
printk("%s: trying to unregister hook on line %d,"
" but none is registered\n", __FUNCTION__, channel);
return 0;
}
}
/*
* ------------------------------------------------------------
* Serial console driver
* ------------------------------------------------------------
*/
#ifdef CONFIG_SERIAL_DEC_CONSOLE
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*/
static void serial_console_write(struct console *co, const char *s,
unsigned count)
{
struct dec_serial *info;
int i;
info = zs_soft + co->index;
for (i = 0; i < count; i++, s++) {
if(*s == '\n')
zs_poll_tx_char(info, '\r');
zs_poll_tx_char(info, *s);
}
}
static struct tty_driver *serial_console_device(struct console *c, int *index)
{
*index = c->index;
return serial_driver;
}
/*
* Setup initial baud/bits/parity. We do two things here:
* - construct a cflag setting for the first rs_open()
* - initialize the serial port
* Return non-zero if we didn't find a serial port.
*/
static int __init serial_console_setup(struct console *co, char *options)
{
struct dec_serial *info;
int baud = 9600;
int bits = 8;
int parity = 'n';
int cflag = CREAD | HUPCL | CLOCAL;
int clk_divisor = 16;
int brg;
char *s;
unsigned long flags;
if(!BUS_PRESENT)
return -ENODEV;
info = zs_soft + co->index;
if (zs_chain == 0)
probe_sccs();
info->is_cons = 1;
if (options) {
baud = simple_strtoul(options, NULL, 10);
s = options;
while(*s >= '0' && *s <= '9')
s++;
if (*s)
parity = *s++;
if (*s)
bits = *s - '0';
}
/*
* Now construct a cflag setting.
*/
switch(baud) {
case 1200:
cflag |= B1200;
break;
case 2400:
cflag |= B2400;
break;
case 4800:
cflag |= B4800;
break;
case 19200:
cflag |= B19200;
break;
case 38400:
cflag |= B38400;
break;
case 57600:
cflag |= B57600;
break;
case 115200:
cflag |= B115200;
break;
case 9600:
default:
cflag |= B9600;
/*
* Set this to a sane value to prevent a divide error.
*/
baud = 9600;
break;
}
switch(bits) {
case 7:
cflag |= CS7;
break;
default:
case 8:
cflag |= CS8;
break;
}
switch(parity) {
case 'o': case 'O':
cflag |= PARODD;
break;
case 'e': case 'E':
cflag |= PARENB;
break;
}
co->cflag = cflag;
spin_lock_irqsave(&zs_lock, flags);
/*
* Set up the baud rate generator.
*/
brg = BPS_TO_BRG(baud, zs_parms->clock / clk_divisor);
info->zs_channel->curregs[R12] = (brg & 255);
info->zs_channel->curregs[R13] = ((brg >> 8) & 255);
/*
* Set byte size and parity.
*/
if (bits == 7) {
info->zs_channel->curregs[R3] |= Rx7;
info->zs_channel->curregs[R5] |= Tx7;
} else {
info->zs_channel->curregs[R3] |= Rx8;
info->zs_channel->curregs[R5] |= Tx8;
}
if (cflag & PARENB) {
info->zs_channel->curregs[R4] |= PAR_ENA;
}
if (!(cflag & PARODD)) {
info->zs_channel->curregs[R4] |= PAR_EVEN;
}
info->zs_channel->curregs[R4] |= SB1;
/*
* Turn on RTS and DTR.
*/
zs_rtsdtr(info, RTS | DTR, 1);
/*
* Finally, enable sequencing.
*/
info->zs_channel->curregs[R3] |= RxENABLE;
info->zs_channel->curregs[R5] |= TxENAB;
/*
* Clear the interrupt registers.
*/
write_zsreg(info->zs_channel, R0, ERR_RES);
write_zsreg(info->zs_channel, R0, RES_H_IUS);
/*
* Load up the new values.
*/
load_zsregs(info->zs_channel, info->zs_channel->curregs);
/* Save the current value of RR0 */
info->read_reg_zero = read_zsreg(info->zs_channel, R0);
zs_soft[co->index].clk_divisor = clk_divisor;
zs_soft[co->index].zs_baud = get_zsbaud(&zs_soft[co->index]);
spin_unlock_irqrestore(&zs_lock, flags);
return 0;
}
static struct console sercons = {
.name = "ttyS",
.write = serial_console_write,
.device = serial_console_device,
.setup = serial_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/*
* Register console.
*/
void __init zs_serial_console_init(void)
{
register_console(&sercons);
}
#endif /* ifdef CONFIG_SERIAL_DEC_CONSOLE */
#ifdef CONFIG_KGDB
struct dec_zschannel *zs_kgdbchan;
static unsigned char scc_inittab[] = {
9, 0x80, /* reset A side (CHRA) */
13, 0, /* set baud rate divisor */
12, 1,
14, 1, /* baud rate gen enable, src=rtxc (BRENABL) */
11, 0x50, /* clocks = br gen (RCBR | TCBR) */
5, 0x6a, /* tx 8 bits, assert RTS (Tx8 | TxENAB | RTS) */
4, 0x44, /* x16 clock, 1 stop (SB1 | X16CLK)*/
3, 0xc1, /* rx enable, 8 bits (RxENABLE | Rx8)*/
};
/* These are for receiving and sending characters under the kgdb
* source level kernel debugger.
*/
void putDebugChar(char kgdb_char)
{
struct dec_zschannel *chan = zs_kgdbchan;
while ((read_zsreg(chan, 0) & Tx_BUF_EMP) == 0)
RECOVERY_DELAY;
write_zsdata(chan, kgdb_char);
}
char getDebugChar(void)
{
struct dec_zschannel *chan = zs_kgdbchan;
while((read_zsreg(chan, 0) & Rx_CH_AV) == 0)
eieio(); /*barrier();*/
return read_zsdata(chan);
}
void kgdb_interruptible(int yes)
{
struct dec_zschannel *chan = zs_kgdbchan;
int one, nine;
nine = read_zsreg(chan, 9);
if (yes == 1) {
one = EXT_INT_ENAB|RxINT_ALL;
nine |= MIE;
printk("turning serial ints on\n");
} else {
one = RxINT_DISAB;
nine &= ~MIE;
printk("turning serial ints off\n");
}
write_zsreg(chan, 1, one);
write_zsreg(chan, 9, nine);
}
static int kgdbhook_init_channel(void *handle)
{
return 0;
}
static void kgdbhook_init_info(void *handle)
{
}
static void kgdbhook_rx_char(void *handle, unsigned char ch, unsigned char fl)
{
struct dec_serial *info = handle;
if (fl != TTY_NORMAL)
return;
if (ch == 0x03 || ch == '$')
breakpoint();
}
/* This sets up the serial port we're using, and turns on
* interrupts for that channel, so kgdb is usable once we're done.
*/
static inline void kgdb_chaninit(struct dec_zschannel *ms, int intson, int bps)
{
int brg;
int i, x;
volatile char *sccc = ms->control;
brg = BPS_TO_BRG(bps, zs_parms->clock/16);
printk("setting bps on kgdb line to %d [brg=%x]\n", bps, brg);
for (i = 20000; i != 0; --i) {
x = *sccc; eieio();
}
for (i = 0; i < sizeof(scc_inittab); ++i) {
write_zsreg(ms, scc_inittab[i], scc_inittab[i+1]);
i++;
}
}
/* This is called at boot time to prime the kgdb serial debugging
* serial line. The 'tty_num' argument is 0 for /dev/ttya and 1
* for /dev/ttyb which is determined in setup_arch() from the
* boot command line flags.
*/
struct dec_serial_hook zs_kgdbhook = {
.init_channel = kgdbhook_init_channel,
.init_info = kgdbhook_init_info,
.rx_char = kgdbhook_rx_char,
.cflags = B38400 | CS8 | CLOCAL,
}
void __init zs_kgdb_hook(int tty_num)
{
/* Find out how many Z8530 SCCs we have */
if (zs_chain == 0)
probe_sccs();
zs_soft[tty_num].zs_channel = &zs_channels[tty_num];
zs_kgdbchan = zs_soft[tty_num].zs_channel;
zs_soft[tty_num].change_needed = 0;
zs_soft[tty_num].clk_divisor = 16;
zs_soft[tty_num].zs_baud = 38400;
zs_soft[tty_num].hook = &zs_kgdbhook; /* This runs kgdb */
/* Turn on transmitter/receiver at 8-bits/char */
kgdb_chaninit(zs_soft[tty_num].zs_channel, 1, 38400);
printk("KGDB: on channel %d initialized\n", tty_num);
set_debug_traps(); /* init stub */
}
#endif /* ifdef CONFIG_KGDB */