From: Ben Gras <ben@minix3.org>
Date: Thu, 13 Jun 2013 13:08:26 +0000 (+0200)
Subject: some arm uart fixes
X-Git-Tag: v3.3.0~920
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=refs%2Fchanges%2F46%2F646%2F2;p=minix.git

some arm uart fixes

	. always keep reading data from uart so the interrupt is
	  not continually asserted if data is sent but no process
	  reads it
	. increase tx & rx fifo trigger levels -> reduces the number
	  of interrupts necessary
	. bigger rx/tx buffers

Change-Id: I3cf7c73b22ae2fc091b845d516ba4aa53e892cda
---

diff --git a/drivers/tty/arch/earm/omap_serial.h b/drivers/tty/arch/earm/omap_serial.h
index 9d4bb0992..1f136caa2 100644
--- a/drivers/tty/arch/earm/omap_serial.h
+++ b/drivers/tty/arch/earm/omap_serial.h
@@ -19,6 +19,7 @@
 #define OMAP3_MCR		4	/* Modem control register */
 #define OMAP3_LSR		5	/* Line status register */
 #define OMAP3_MSR		6	/* Modem status register */
+#define OMAP3_TCR		6
 #define OMAP3_MDR1		0x08	/* Mode definition register 1 */
 #define OMAP3_MDR2		0x09	/* Mode definition register 2 */
 #define OMAP3_SCR		0x10	/* Supplementary control register */
@@ -28,6 +29,8 @@
 
 /* Enhanced Features Register bits */
 #define UART_EFR_ECB		(1 << 4)/* Enhanced control bit */
+#define UART_EFR_AUTO_CTS	(1 << 6)/* auto cts enable */
+#define UART_EFR_AUTO_RTS	(1 << 7)/* auto rts enable */
 
 /* Interrupt Enable Register bits */
 #define UART_IER_MSI		0x08	/* Modem status interrupt */
@@ -38,6 +41,8 @@
 /* FIFO control register */
 #define OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT	6
 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK		(0x3 << 6)
+#define OMAP_UART_FCR_TX_FIFO_TRIG_SHIFT	4
+#define OMAP_UART_FCR_RX_FIFO_TRIG_MASK		(0x3 << 4)
 #define UART_FCR_ENABLE_FIFO	0x01	/* Enable the fifo */
 #define UART_FCR_CLR_RCVR	0x02	/* Clear the RCVR FIFO */
 #define UART_FCR_CLR_XMIT	0x04	/* Clear the XMIT FIFO */
diff --git a/drivers/tty/arch/earm/rs232.c b/drivers/tty/arch/earm/rs232.c
index 46e5dec56..432d2d9cf 100644
--- a/drivers/tty/arch/earm/rs232.c
+++ b/drivers/tty/arch/earm/rs232.c
@@ -18,8 +18,8 @@
 #endif
 
 
-#define RS_IBUFSIZE          1024	/* RS232 input buffer size */
-#define RS_OBUFSIZE          1024	/* RS232 output buffer size */
+#define RS_IBUFSIZE          40960	/* RS232 input buffer size */
+#define RS_OBUFSIZE          40960	/* RS232 output buffer size */
 
 /* Input buffer watermarks.
  * The external device is asked to stop sending when the buffer
@@ -101,10 +101,7 @@ typedef struct rs232 {
   unsigned int uartclk;		/* UART clock rate */
 
   unsigned char lstatus;	/* last line status */
-  unsigned framing_errors;	/* error counts (no reporting yet) */
-  unsigned overrun_errors;
-  unsigned parity_errors;
-  unsigned break_interrupts;
+  int rx_overrun_events;
 
   int irq;			/* irq for this line */
   int irq_hook_id;		/* interrupt hook */
@@ -390,8 +387,9 @@ static void rs_config(rs232_t *rs)
 	serial_out(rs, OMAP3_MCR, mcr | UART_MCR_TCRTLR);	/* 4b */
 	/* Set up FIFO  */
 	rs->fcr = 0;
-	rs->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
-	rs->fcr |= (0x1 << OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT);
+	/* Set FIFO interrupt trigger levels high */
+	rs->fcr |= (0x3 << OMAP_UART_FCR_RX_FIFO_TRIG_SHIFT);
+	rs->fcr |= (0x3 << OMAP_UART_FCR_TX_FIFO_TRIG_SHIFT);
 	rs->fcr |= UART_FCR_ENABLE_FIFO;
 	serial_out(rs, OMAP3_FCR, rs->fcr);			/* 5  */
 	serial_out(rs, OMAP3_LCR, UART_LCR_CONF_MODE_B);	/* 6  */
@@ -470,6 +468,7 @@ static void rs_config(rs232_t *rs)
 	if ((tp->tty_termios.c_lflag & IXON) && rs->oxoff != _POSIX_VDISABLE)
 		rs->ostate &= ~ORAW;
 	(void) serial_in(rs, OMAP3_IIR);
+
 	if (sys_irqenable(&rs->irq_hook_kernel_id) != OK)
 		panic("unable to enable interrupts");
 }
@@ -737,9 +736,12 @@ read_chars(rs232_t *rs, unsigned int status)
 {
 	unsigned char c;
 
+	if(serial_in(rs,OMAP3_LSR) & OMAP3_LSR_RXOE) {
+		rs->rx_overrun_events++;
+	}
+
 	/* check the line status to know if there are more chars */
 	while (serial_in(rs, OMAP3_LSR) &  UART_LSR_DR) {
-		assert( (serial_in(rs,OMAP3_LSR) & OMAP3_LSR_RXOE) == 0);
 		c = serial_in(rs, OMAP3_RHR);
 		if (!(rs->ostate & ORAW)) {
 			if (c == rs->oxoff) {
@@ -750,9 +752,8 @@ read_chars(rs232_t *rs, unsigned int status)
 		}
 
 		if (rs->icount == buflen(rs->ibuf)) {
-			printf("%s:%d buffer full, discarding byte\n",
-				__FUNCTION__, __LINE__);
-			return;
+			/* no buffer space? keep reading */
+			continue;
 		}
 
 		if (++rs->icount == RS_IHIGHWATER && rs->idevready) {