[SERIAL] sunzilog: Interrupt enable before ISR handler installed

This patch changes the interrupt enable sequence for the sunzilog driver 
so that interrupts are not enabled untill after the interrupt handler has 
been installed. If this is not done, some SS1 and SS2 sun4c systems panic 
on un-handled interrupt before the handler gets installed preventing boot.

It also adds in support for the ESCC version of the zilog chips. The
changes mean that the FIFO will be enabled for ESCC versions of the
SCC UART. My interpretation of the SCC manual and the existing interrupt
handler code is that it sould be able to make good use of the FIFO without
issues.

Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/serial/sunzilog.h b/drivers/serial/sunzilog.h
index 7939b6d..5dec7b4 100644
--- a/drivers/serial/sunzilog.h
+++ b/drivers/serial/sunzilog.h
@@ -13,7 +13,8 @@
 	struct zilog_channel channelA;
 };
 
-#define NUM_ZSREGS    16
+#define	NUM_ZSREGS	17
+#define	R7p		16 /* Written as R7 with P15 bit 0 set */
 
 /* Conversion routines to/from brg time constants from/to bits
  * per second.
@@ -127,6 +128,15 @@
 
 /* Write Register 7 (Sync bits 8-15/SDLC 01111110) */
 
+/* Write Register 7' (ESCC Only) */
+#define	AUTO_TxFLAG	1	/* Automatic Tx SDLC Flag */
+#define	AUTO_EOM_RST	2	/* Automatic EOM Reset */
+#define	AUTOnRTS	4	/* Automatic /RTS pin deactivation */
+#define	RxFIFO_LVL	8	/* Receive FIFO interrupt level */
+#define	nDTRnREQ	0x10	/* /DTR/REQ timing */
+#define	TxFIFO_LVL	0x20	/* Transmit FIFO interrupt level */
+#define	EXT_RD_EN	0x40	/* Extended read register enable */
+
 /* Write Register 8 (transmit buffer) */
 
 /* Write Register 9 (Master interrupt control) */
@@ -135,6 +145,7 @@
 #define	DLC	4	/* Disable Lower Chain */
 #define	MIE	8	/* Master Interrupt Enable */
 #define	STATHI	0x10	/* Status high */
+#define	SWIACK  0x20    /* Software Interrupt Ack (not on NMOS) */
 #define	NORESET	0	/* No reset on write to R9 */
 #define	CHRB	0x40	/* Reset channel B */
 #define	CHRA	0x80	/* Reset channel A */
@@ -187,7 +198,9 @@
 #define	SNRZI	0xe0	/* Set NRZI mode */
 
 /* Write Register 15 (external/status interrupt control) */
+#define	WR7pEN	1	/* WR7' Enable (ESCC only) */
 #define	ZCIE	2	/* Zero count IE */
+#define	FIFOEN	4	/* FIFO Enable (ESCC only) */
 #define	DCDIE	8	/* DCD IE */
 #define	SYNCIE	0x10	/* Sync/hunt IE */
 #define	CTSIE	0x20	/* CTS IE */
@@ -241,6 +254,10 @@
 #define	CHATxIP	0x10		/* Channel A Tx IP */
 #define	CHARxIP	0x20		/* Channel A Rx IP */
 
+/* Read Register 6 (LSB frame byte count [Not on NMOS]) */
+
+/* Read Register 7 (MSB frame byte count and FIFO status [Not on NMOS]) */
+
 /* Read Register 8 (receive data register) */
 
 /* Read Register 10  (misc status bits) */