PERFORCE change 36807 for review

[Marcel Moolenaar]

http://perforce.freebsd.org/chv.cgi?CH=36807

Change 36807 by marcel at marcel_nfs on 2003/08/23 18:23:15

	Implement UART_FLUSH(). Note that we get a XPR interrupt when
	we reset the transmitter. Since we cannot detect a bogus XPR
	from a real one by only looking at the RBCL register, we now
	first check SAB_STAR_RFNE. If it indicates that there's at
	least 1 character in the RFIFO, we read RBCL, and then read
	the data from the RFIFO.

Affected files ...

.. //depot/projects/uart/dev/uart/uart_dev_sab82532.c#14 edit

Differences ...

==== //depot/projects/uart/dev/uart/uart_dev_sab82532.c#14 (text+ko) ====

@@ -102,6 +102,24 @@
 	return (0);
 }
 
+static void
+sab82532_flush(struct uart_bas *bas, int what)
+{
+
+	if (what & UART_FLUSH_TRANSMITTER) {
+		while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
+			;
+		uart_setreg(bas, SAB_CMDR, SAB_CMDR_XRES);
+		uart_barrier(bas);
+	}
+	if (what & UART_FLUSH_RECEIVER) {
+		while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
+			;
+		uart_setreg(bas, SAB_CMDR, SAB_CMDR_RRES);
+		uart_barrier(bas);
+	}
+}
+
 static int
 sab82532_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
     int parity)
@@ -227,16 +245,8 @@
 	    SAB_RFC_RFTH_32CHAR);
 	uart_barrier(bas);
 
-	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
-		;
-	uart_setreg(bas, SAB_CMDR, SAB_CMDR_XRES);
-	uart_barrier(bas);
-	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
-		;
-	uart_setreg(bas, SAB_CMDR, SAB_CMDR_RRES);
-	uart_barrier(bas);
-
 	sab82532_param(bas, baudrate, databits, stopbits, parity);
+	sab82532_flush(bas, UART_FLUSH_TRANSMITTER|UART_FLUSH_RECEIVER);
 
 	/* Clear interrupts. */
 	uart_setreg(bas, SAB_IMR0, 0xff);
@@ -298,9 +308,9 @@
 
 	while (!(uart_getreg(bas, SAB_STAR) & SAB_STAR_RFNE))
 		DELAY(delay);
+
 	while (uart_getreg(bas, SAB_STAR) & SAB_STAR_CEC)
 		;
-
 	uart_setreg(bas, SAB_CMDR, SAB_CMDR_RFRD);
 	uart_barrier(bas);
 
@@ -405,6 +415,7 @@
 sab82532_bus_flush(struct uart_softc *sc, int what)
 {
 
+	sab82532_flush(&sc->sc_bas, what);
 	return (0);
 }
 
@@ -503,9 +514,12 @@
 {
 	struct uart_bas *bas;
 	int count, xc;
-	uint8_t s;
+	uint8_t s, star;
 
 	bas = &sc->sc_bas;
+	star = uart_getreg(bas, SAB_STAR);
+	if (!(star & SAB_STAR_RFNE))
+		return (0);
 	count = uart_getreg(bas, SAB_RBCL) & 31;
 	if (count == 0)
 		count = 32;