usbdux: usbduxsigma: added digital IO read

for future driver versions I've added a digtial I/O read via
endpoint in1. This is not yet used but might be used in the
future for low latency IO reads if all ports are input ports
and thus the write could be omitted.
Signed-off-by: Bernd Porr <mail@berndporr.me.uk>
Signed-off-by: Kyle McMartin <kyle@kernel.org>

usbdux/usbduxsigma_firmware.asm

@@ -20,8 +20,8 @@
 ; Firmware: usbduxsigma_firmware.asm for usbduxsigma.c
 ; Description: University of Stirling USB DAQ & INCITE Technology Limited
 ; Devices: [ITL] USB-DUX-SIGMA (usbduxsigma.ko)
-; Author: Bernd Porr <Bernd.Porr@f2s.com>
-; Updated: 19 Jul 2015
+; Author: Bernd Porr <mail@berndporr.me.uk>
+; Updated: 20 Jul 2015
 ; Status: testing
 ;
 ;;;
@@ -129,7 +129,6 @@ ep0ack_isr:
 spare_isr:	
 ep0in_isr:	
 ep0out_isr:	
-ep1in_isr:	
 ibn_isr:	
 ep0ping_isr:	
 ep1ping_isr:	
@@ -169,6 +168,49 @@ ep4_isr:
 	
 	reti
 
+
+ep1in_isr:	
+	push	dps
+	push	dpl
+	push	dph
+	push	dpl1
+	push	dph1
+	push	acc
+	push	psw
+		
+	mov	dptr,#0E7C0h	; EP1in
+	mov	a,IOB		; get DIO D
+	movx	@dptr,a		; store it
+	inc	dptr		; next byte
+	mov	a,IOC		; get DIO C
+	movx	@dptr,a		; store it
+	inc	dptr		; next byte
+	mov	a,IOD		; get DIO B
+	movx	@dptr,a		; store it
+	inc	dptr		; next byte
+	mov	a,#0		; just zero
+	movx	@dptr,a		; pad it up
+
+	;; clear INT2
+	mov	a,EXIF		; FIRST clear the USB (INT2) interrupt request
+	clr	acc.4
+	mov	EXIF,a		; Note: EXIF reg is not 8051 bit-addressable
+
+	mov	DPTR,#EPIRQ	; 
+	mov	a,#00000100b	; clear the ep1in
+	movx	@DPTR,a
+
+	pop	psw
+	pop	acc 
+	pop	dph1 
+	pop	dpl1
+	pop	dph 
+	pop	dpl 
+	pop	dps
+	reti
+
+
+
 ;;; this is triggered when DRY goes low
 isr0:	
 	push	dps
@@ -476,11 +518,11 @@ initeps:
 
 	;; enable interrupts
 	mov	dptr,#EPIE	; interrupt enable
-	mov	a,#10001000b	; enable irq for ep1out,8
+	mov	a,#10001100b	; enable irq for ep1out,8,ep1in
 	movx	@dptr,a		; do it
 
 	mov	dptr,#EPIRQ	; clear IRQs
-	mov	a,#10001000b
+	mov	a,#10001100b
 	movx	@dptr,a
 	
         mov     DPTR,#USBIE	; USB int enables register