[RFC] handshake variable with DTR DSR DCD ...

From: Michael Westermann
Date: Fri May 07 2004 - 09:56:43 EST

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Hello,

this is a patch to allow arbitrary serial status lines to be
used for hardware handshake. It's mainly useful for DTR/DSR
handshake.

diff -Nurp linux-2.4.26.old/drivers/char/serial.c linux-2.4.26/drivers/char/serial.c
--- linux-2.4.26.old/drivers/char/serial.c 2004-02-18 14:36:31.000000000 +0100
+++ linux-2.4.26/drivers/char/serial.c 2004-05-07 16:42:19.000000000 +0200
@@ -769,9 +769,12 @@ static _INLINE_ void check_modem_status(
}
if (info->flags & ASYNC_CTS_FLOW) {
if (info->tty->hw_stopped) {
- if (status & UART_MSR_CTS) {
+ if (status & info->status_flow) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
- printk("CTS tx start...");
+ if (info->status_flow & UART_MSR_CTS)
+ printk("CTS tx start...");
+ else
+ printk("HW %x tx start...", info->status_flow);
#endif
info->tty->hw_stopped = 0;
info->IER |= UART_IER_THRI;
@@ -780,9 +783,12 @@ static _INLINE_ void check_modem_status(
return;
}
} else {
- if (!(status & UART_MSR_CTS)) {
+ if (!(status & info->status_flow)) {
#if (defined(SERIAL_DEBUG_INTR) || defined(SERIAL_DEBUG_FLOW))
- printk("CTS tx stop...");
+ if (info->status_flow & UART_MSR_CTS)
+ printk("CTS tx stop...");
+ else
+ printk("HW %x tx stop...", info->status_flow);
#endif
info->tty->hw_stopped = 1;
info->IER &= ~UART_IER_THRI;
@@ -1749,9 +1755,13 @@ static void change_speed(struct async_st
info->IER &= ~UART_IER_MSI;
if (info->flags & ASYNC_HARDPPS_CD)
info->IER |= UART_IER_MSI;
- if (cflag & CRTSCTS) {
+ if (cflag & (CRTSCTS|CHWFLOW)) {
info->flags |= ASYNC_CTS_FLOW;
info->IER |= UART_IER_MSI;
+ if (!(cflag & CHWFLOW)) {
+ info->status_flow = UART_MSR_CTS;
+ info->modem_flow = UART_MCR_RTS;
+ }
} else
info->flags &= ~ASYNC_CTS_FLOW;
if (cflag & CLOCAL)
@@ -2018,8 +2028,8 @@ static void rs_throttle(struct tty_struc
if (I_IXOFF(tty))
rs_send_xchar(tty, STOP_CHAR(tty));

- if (tty->termios->c_cflag & CRTSCTS)
- info->MCR &= ~UART_MCR_RTS;
+ if (tty->termios->c_cflag & (CRTSCTS|CHWFLOW))
+ info->MCR &= ~info->modem_flow;

save_flags(flags); cli();
serial_out(info, UART_MCR, info->MCR);
@@ -2046,8 +2056,8 @@ static void rs_unthrottle(struct tty_str
else
rs_send_xchar(tty, START_CHAR(tty));
}
- if (tty->termios->c_cflag & CRTSCTS)
- info->MCR |= UART_MCR_RTS;
+ if (tty->termios->c_cflag & (CRTSCTS|CHWFLOW))
+ info->MCR |= info->modem_flow;
save_flags(flags); cli();
serial_out(info, UART_MCR, info->MCR);
restore_flags(flags);
@@ -2352,6 +2362,46 @@ static int set_modem_info(struct async_s
| ((arg & TIOCM_LOOP) ? UART_MCR_LOOP : 0)
| ((arg & TIOCM_DTR) ? UART_MCR_DTR : 0));
break;
+ case TIOHWFLOWBIS:
+ if (arg & TIOCM_RTS)
+ info->modem_flow |= UART_MCR_RTS;
+ if (arg & TIOCM_DTR)
+ info->modem_flow |= UART_MCR_DTR;
+#ifdef TIOCM_OUT1
+ if (arg & TIOCM_OUT1)
+ info->modem_flow |= UART_MCR_OUT1;
+ if (arg & TIOCM_OUT2)
+ info->modem_flow |= UART_MCR_OUT2;
+#endif
+ if (arg & TIOCM_CTS)
+ info->status_flow |= UART_MSR_CTS;
+ if (arg & TIOCM_DSR)
+ info->status_flow |= UART_MSR_DSR;
+ if (arg & TIOCM_RI)
+ info->status_flow |= UART_MSR_RI;
+ if (arg & TIOCM_CD)
+ info->status_flow |= UART_MSR_DCD;
+ break;
+ case TIOHWFLOWBIC:
+ if (arg & TIOCM_RTS)
+ info->modem_flow &= ~UART_MCR_RTS;
+ if (arg & TIOCM_DTR)
+ info->modem_flow &= ~UART_MCR_DTR;
+#ifdef TIOCM_OUT1
+ if (arg & TIOCM_OUT1)
+ info->modem_flow &= ~UART_MCR_OUT1;
+ if (arg & TIOCM_OUT2)
+ info->modem_flow &= ~UART_MCR_OUT2;
+#endif
+ if (arg & TIOCM_CTS)
+ info->status_flow &= ~UART_MSR_CTS;
+ if (arg & TIOCM_DSR)
+ info->status_flow &= ~UART_MSR_DSR;
+ if (arg & TIOCM_RI)
+ info->status_flow &= ~UART_MSR_RI;
+ if (arg & TIOCM_CD)
+ info->status_flow &= ~UART_MSR_DCD;
+ break;
default:
return -EINVAL;
}
@@ -2605,6 +2655,8 @@ static int rs_ioctl(struct tty_struct *t
#endif
case TIOCMGET:
return get_modem_info(info, (unsigned int *) arg);
+ case TIOHWFLOWBIS:
+ case TIOHWFLOWBIC:
case TIOCMBIS:
case TIOCMBIC:
case TIOCMSET:
@@ -2734,9 +2786,9 @@ static void rs_set_termios(struct tty_st
if (!(old_termios->c_cflag & CBAUD) &&
(cflag & CBAUD)) {
info->MCR |= UART_MCR_DTR;
- if (!(tty->termios->c_cflag & CRTSCTS) ||
+ if (!(tty->termios->c_cflag & (CRTSCTS|CHWFLOW)) ||
!test_bit(TTY_THROTTLED, &tty->flags)) {
- info->MCR |= UART_MCR_RTS;
+ info->MCR |= info->status_flow;
}
save_flags(flags); cli();
serial_out(info, UART_MCR, info->MCR);
@@ -2744,8 +2796,8 @@ static void rs_set_termios(struct tty_st
}

/* Handle turning off CRTSCTS */
- if ((old_termios->c_cflag & CRTSCTS) &&
- !(tty->termios->c_cflag & CRTSCTS)) {
+ if ((old_termios->c_cflag & (CRTSCTS|CHWFLOW)) &&
+ !(tty->termios->c_cflag & (CRTSCTS|CHWFLOW))) {
tty->hw_stopped = 0;
rs_start(tty);
}
diff -Nurp linux-2.4.26.old/include/asm-i386/ioctls.h linux-2.4.26/include/asm-i386/ioctls.h
--- linux-2.4.26.old/include/asm-i386/ioctls.h 2003-08-25 13:44:43.000000000 +0200
+++ linux-2.4.26/include/asm-i386/ioctls.h 2004-05-07 13:48:28.000000000 +0200
@@ -68,6 +68,8 @@
#define TIOCGHAYESESP 0x545E /* Get Hayes ESP configuration */
#define TIOCSHAYESESP 0x545F /* Set Hayes ESP configuration */
#define FIOQSIZE 0x5460
+#define TIOHWFLOWBIS 0x5461 /* Set hardware flow Control */
+#define TIOHWFLOWBIC 0x5462 /* Clear hardware flow Control */

/* Used for packet mode */
#define TIOCPKT_DATA 0
diff -Nurp linux-2.4.26.old/include/asm-i386/termbits.h linux-2.4.26/include/asm-i386/termbits.h
--- linux-2.4.26.old/include/asm-i386/termbits.h 2000-01-21 01:05:26.000000000 +0100
+++ linux-2.4.26/include/asm-i386/termbits.h 2004-05-07 16:43:39.000000000 +0200
@@ -132,6 +132,7 @@ struct termios {
#define B3000000 0010015
#define B3500000 0010016
#define B4000000 0010017
+#define CHWFLOW 001000000000 /* flexible hw flow_ctrl */
#define CIBAUD 002003600000 /* input baud rate (not used) */
#define CMSPAR 010000000000 /* mark or space (stick) parity */
#define CRTSCTS 020000000000 /* flow control */
diff -Nurp linux-2.4.26.old/include/linux/serialP.h linux-2.4.26/include/linux/serialP.h
--- linux-2.4.26.old/include/linux/serialP.h 2002-08-03 02:39:45.000000000 +0200
+++ linux-2.4.26/include/linux/serialP.h 2004-05-07 14:06:30.000000000 +0200
@@ -68,6 +68,8 @@ struct async_struct {
int timeout;
int quot;
int x_char; /* xon/xoff character */
+ int status_flow; /* status mask hw-flowcontrol */
+ int modem_flow; /* modem mask hw-flowcontrol */
int close_delay;
unsigned short closing_wait;
unsigned short closing_wait2;

It's only i386 yet, but please comment on it!

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Next message: James Morris: "[PATCH][SELINUX] 2/2 sock_create_lite()"
Previous message: Kevin P. Fleming: "Re: [ACPI] [PATCH] can we compile ACPI without define CONFIG_PM ?"
Next in thread: Jan-Benedict Glaw: "Re: [RFC] handshake variable with DTR DSR DCD ..."
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]