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handshake variable with DTR DSR DCD ...

RFC In review Michael Westermann 2 participants 2 messages May 7, 2004 Char and misc drivers

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Michael Westermann

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#0 lore raw

RFC 1/1 handshake variable with DTR DSR DCD ...

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.

drivers/char/serial.c +65 -13
diff -Nurp linux-2.4.26.old/drivers/char/serial.c linux-2.4.26/drivers/char/serial.c
@@ -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);
 	}
include/asm-i386/ioctls.h +2 -0
diff -Nurp linux-2.4.26.old/include/asm-i386/ioctls.h linux-2.4.26/include/asm-i386/ioctls.h
@@ -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
include/asm-i386/termbits.h +1 -0
diff -Nurp linux-2.4.26.old/include/asm-i386/termbits.h linux-2.4.26/include/asm-i386/termbits.h
@@ -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 */
include/linux/serialP.h +2 -0
diff -Nurp linux-2.4.26.old/include/linux/serialP.h linux-2.4.26/include/linux/serialP.h
@@ -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!

#1 lore raw

On Fri, 2004-05-07 16:54:13 +0200, Michael Westermann <[email protected]> wrote in message <[email protected]>:

Quoted 5 lines

diff -Nurp linux-2.4.26.old/drivers/char/serial.c linux-2.4.26/drivers/char/serial.c

drivers/char/serial.c +0 -0
@@ -769,9 +769,12 @@ static _INLINE_ void check_modem_status(
 	}

drivers/char/serial.c static _INLINE_ void check_modem_status( · line 777

Quoted 10 lines
drivers/char/serial.c +5 -2
 	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);

A "\n" is missing here and was already missing in the initial version.

drivers/char/serial.c static _INLINE_ void check_modem_status( · line 791

Quoted 6 lines
drivers/char/serial.c +4 -1
 #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);

Dito.

Quoted 11 lines
include/asm-i386/termbits.h +1 -0
@@ -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 */
Quoted 1 line

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

I won't comment on the code itself, as I don't know the 2.4.x serial driver all that good:) Of course, non-i386 code would be cool, too:)

MfG, JBG

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