usbdux: usbduxsigma: changed firmware from ADC polling to IRQ processing

In order to prepare the firmware to work with the EHCI driver the
ADC data acquisition is now done by triggering the acquisition with
a start of frame interrupt (SOF) and then the collection of the data
is done via "data ready" interrupts until all data has been received.
Once this has happend then the whole packet is dispatched and at the
next SOF the next packet is dispatched. If there are SOF interrupts
happening during the data acquisiton it is no longer interupted and
only send out the next ISO packet once it has comleted its job.
Also now the USBDUXSIGMA has now plenty of time to deal with other
interrupts between ADC data readouts so that for example the DIO
can now be handled much quicker.

Signed-off-by: Bernd Porr <mail@berndporr.me.uk>
Signed-off-by: Kyle McMartin <kyle@kernel.org>

usbdux/usbduxsigma_firmware.asm

@@ -1,5 +1,5 @@
 ;   usbdux_firmware.asm
-;   Copyright (C) 2010,2011,2015 Bernd Porr, mail@berndporr.me.uk
+;   Copyright (C) 2010,2011 Bernd Porr, Bernd.Porr@f2s.com
 ;   For usbduxsigma.c 0.5+
 ;
 ;   This program is free software; you can redistribute it and/or modify
@@ -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 <mail@berndporr.me.uk>
-; Updated: 25 Jun 2015
+; Author: Bernd Porr <Bernd.Porr@f2s.com>
+; Updated: 24 Jul 2011
 ; Status: testing
 ;
 ;;;
@@ -35,14 +35,21 @@
 	.equ	PWMFLAG,81h	; PWM on or off?
 	.equ	MAXSMPL,82H	; maximum number of samples, n channellist
 	.equ	MUXSG0,83H	; content of the MUXSG0 register
+	.equ	SMPLCTR,84h
+	.equ	DPTRL,85H
+	.equ	DPTRH,86h
+	.equ	ASYNC_ON,87h
 
 ;;; actual code
 	.org	0000h		; after reset the processor starts here
 	ljmp	main		; jump to the main loop
 
+	.org	0003h
+	ljmp	isr0		; external interrupt 0: /DRY
+
 	.org	0043h		; the IRQ2-vector
 	ljmp	jmptbl		; irq service-routine
-	
+
 	.org	0100h		; start of the jump table
 
 jmptbl:	ljmp	sudav_isr
@@ -160,6 +167,85 @@ ep4_isr:
 	
 	reti
 
+;;; this is triggered when DRY goes low
+isr0:	
+	push	dps
+	push	dpl
+	push	dph
+	push	dpl1
+	push	dph1
+	push	acc
+	push	psw
+	push	00h		; R0
+	push	01h		; R1
+	push	02h		; R2
+	push	03h		; R3
+	push	04h		; R4
+	push	05h		; R5
+	push	06h		; R6
+	push	07h		; R7
+
+	mov	r0,#ASYNC_ON
+	mov	a,@r0
+	jz	noepsubmit
+
+	mov	DPS,#0
+	mov	r0,#DPTRL
+	mov	dpl,@r0
+	inc	r0
+	mov	dph,@r0
+
+	lcall	readADCch	; read one channel
+
+	mov	r0,#DPTRL
+	mov	@r0,dpl
+	inc	r0
+	mov	@r0,dph
+
+	mov	r0,#SMPLCTR
+	mov	a,@r0
+	dec	a
+	mov	@r0,a
+	jnz	noepsubmit
+
+	mov	r0,#ASYNC_ON
+	mov	@r0,#0
+
+	clr	IOA.7		; START = 0
+	
+	;; arm the endpoint and send off the data
+	mov	DPTR,#EP6BCH	; byte count H
+	mov	a,#0		; is zero
+	lcall	syncdelaywr	; wait until we can write again
+	
+	mov	r0,#MAXSMPL	; number of samples to transmit
+	mov	a,@r0		; get them
+	rl	a		; a=a*2
+	rl	a		; a=a*2
+	add	a,#4		; four bytes for DIO
+	mov	DPTR,#EP6BCL	; byte count L
+	lcall	syncdelaywr	; wait until we can write again
+
+noepsubmit:
+	pop	07h
+	pop	06h
+	pop	05h
+	pop	04h		; R4
+	pop	03h		; R3
+	pop	02h		; R2
+	pop	01h		; R1
+	pop	00h		; R0
+	pop	psw
+	pop	acc 
+	pop	dph1 
+	pop	dpl1
+	pop	dph 
+	pop	dpl 
+	pop	dps
+
+	reti
+
+	
 		
 ;;; main program
 ;;; basically only initialises the processor and
@@ -211,6 +297,9 @@ initAD:
 	mov	r0,#MAXSMPL	; length of channellist
 	mov	@r0,#0		; we don't want to accumlate samples
 
+	mov	r0,#ASYNC_ON	; async enable
+	mov	@r0,#0		; we don't want to accumlate samples
+
 	mov	OEA,#11100000b	; PortA7,A6,A5 Outputs
 	mov	IOA,#01100000b	; /CS = 1 and START = 0
 	mov	dptr,#IFCONFIG	; switch on clock on IFCLK pin
@@ -379,6 +468,10 @@ initeps:
 	mov	a,#11100000b	; BULK data from here to the host
 	movx	@DPTR,a		;
 
+	mov	dptr,#PORTACFG
+	mov	a,#1		; interrupt on pin A0
+	lcall	syncdelaywr
+
 	;; enable interrupts
 	mov	dptr,#EPIE	; interrupt enable
 	mov	a,#10001000b	; enable irq for ep1out,8
@@ -392,8 +485,10 @@ initeps:
         mov     a,#2            ; enables SOF (1ms/125us interrupt)
         movx    @DPTR,a         ; 
 
+	setb	TCON.0		; make INT0 edge triggered, falling edge
+
 	mov	EIE,#00000001b	; enable INT2/USBINT in the 8051's SFR
-	mov	IE,#80h		; IE, enable all interrupts
+	mov	IE,#81h		; IE, enable all interrupts and INT0
 
 	ret
 
@@ -401,10 +496,6 @@ initeps:
 ;;; Reads one ADC channel from the converter and stores
 ;;; the result at dptr
 readADCch:
-	;; we do polling: we wait until DATA READY is zero
-	mov	a,IOA		; get /DRDY
-	jb	ACC.0,readADCch	; wait until data ready (DRDY=0)
-	
 	;; reading data is done by just dropping /CS and start reading and
 	;; while keeping the IN signal to the ADC inactive
 	clr	IOA.5		; /cs to 0
@@ -460,7 +551,8 @@ sof_isr:
 	anl	a,#20H		; full?
 	jnz	epfull		; EP6-buffer is full
 
-	clr	IOA.7		; stop converter, START = 0
+	mov	a,IOA		; conversion running?
+	jb	ACC.7,epfull
 
 	;; make sure that we are starting with the first channel
 	mov	r0,#MUXSG0	;
@@ -471,8 +563,6 @@ sof_isr:
 
 	setb	IOA.7		; start converter, START = 1
 	
-	;; get the data from the ADC as fast as possible and transfer it
-	;; to the EP buffer
 	mov	dptr,#0f800h	; EP6 buffer
 	mov	a,IOD		; get DIO D
 	movx	@dptr,a		; store it
@@ -486,30 +576,18 @@ sof_isr:
 	mov	a,#0		; just zero
 	movx	@dptr,a		; pad it up
 	inc	dptr		; algin along a 32 bit word
+	mov	r0,#DPTRL
+	mov	@r0,dpl
+	inc	r0
+	mov	@r0,dph
 
-	mov	r0,#MAXSMPL	; number of samples to transmit
-	mov	a,@r0		; get them
-	mov	r1,a		; counter
-
-	;; main loop, get all the data
-eptrans:	
-	lcall	readADCch	; get one reading
-	djnz	r1,eptrans	; do until we have all content transf'd
+	mov	r0,#MAXSMPL
+	mov	a,@r0
+	mov	r0,#SMPLCTR
+	mov	@r0,a
 
-	clr	IOA.7		; stop converter, START = 0
-
-	;; arm the endpoint and send off the data
-	mov	DPTR,#EP6BCH	; byte count H
-	mov	a,#0		; is zero
-	lcall	syncdelaywr	; wait until we can write again
-	
-	mov	r0,#MAXSMPL	; number of samples to transmit
-	mov	a,@r0		; get them
-	rl	a		; a=a*2
-	rl	a		; a=a*2
-	add	a,#4		; four bytes for DIO
-	mov	DPTR,#EP6BCL	; byte count L
-	lcall	syncdelaywr	; wait until we can write again
+	mov	r0,#ASYNC_ON
+	mov	@r0,#1		; enable data collection
 
 epfull:
 	;; do the D/A conversion
@@ -697,6 +775,9 @@ pwm_off:
 	sjmp	over_da
 
 initsgADchannel:
+	mov	r0,#ASYNC_ON
+	mov	@r0,#0		; make sure that no async activity is on
+	
 	mov	dptr,#0e781h	; FIFO buffer of EP1OUT
 	lcall	configADC	; configures the ADC esp sel the channel
 
@@ -719,9 +800,14 @@ startadc:
 	inc	dptr
 	mov	r0,#MAXSMPL
 	mov	@r0,a 		; length of the channel list
+	mov	r0,#SMPLCTR
+	mov	@r0,a
 
 	lcall	configADC	; configures all registers
 
+	mov	r0,#ASYNC_ON	; async enable
+	mov	@r0,#1		; enable it
+
 	lcall	reset_ep6	; reset FIFO
 	
 	;; load new A/D data into EP6
@@ -915,8 +1001,12 @@ ep8_jmp:
 
 	;; read one A/D channel
 ep8_sglchannel:
-	mov 	DPTR,#0fc01h	; EP8 FIFO
 	setb	IOA.7		; start converter, START = 1
+	;; we do polling: we wait until DATA READY is zero
+sglchwait:	
+	mov	a,IOA		; get /DRDY
+	jb	ACC.0,sglchwait	; wait until data ready (DRDY=0)
+	mov 	DPTR,#0fc01h	; EP8 FIFO
 	lcall	readADCch	; get one reading
 	clr	IOA.7		; stop the converter, START = 0