From 1135ff9d1e3dea2ee6ed3044afe8d0f77578eeff Mon Sep 17 00:00:00 2001
From: ian <ian>
Date: Sun, 13 Nov 2005 15:14:33 +0000
Subject: [PATCH] wip; before undo redo i2cs_interrupt

---
 detpic/i2clib.asm | 47 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/detpic/i2clib.asm b/detpic/i2clib.asm
index f008d4d..e5f9cd3 100644
--- a/detpic/i2clib.asm
+++ b/detpic/i2clib.asm
@@ -14,8 +14,8 @@
 
 t		res	1
 
-st		res	1
-st_subsequent	equ	0
+st		res	1	; bitmask:
+st_writing	equ	0
 
 		code
 
@@ -58,6 +58,49 @@ i2cs_interrupt_wcolsspov_endif
 
 ; Find out what's just happened:
 		mov_ff	SSPSTAT, t
+			; bits we want to check
+			;  80  60  20    10    08    04    02  01
+			;  SMP CKE D_A   P     S     R_W   UA  BF
+			;  set clr data? stop  start read? clr full?
+
+		bt_f_if1 t, I2C_START
+		bra	si_if_start
+
+si_if_notstart
+		; So it should be stop
+		mov_fw	t
+		and_lw	0xdf ; ?D_A
+		xor_lw	0x90 ; SMP, !CKE, P; !S, !R_W, !UA, !BF
+		bra_nz	si_if_bad
+
+		; Were we receiving ?
+		bt_f_if0 st, st_writing
+		return
+
+		; Yes, we were receiving:
+		bc_f	st, st_writing
+		goto	i2csu_write_done
+		; tail call; we couldn't do anything after that
+		; anyway since it might well reenter us.
+
+si_if_start
+		bt_f_if1 t, BF
+		bra	si_if_bufferfull
+si_if_bufferempty
+		bt_f_if1 t, R_W ;read?
+		bra	si_if_bufferempty_reading
+si_if_bufferempty_notreading
+		; So we think this is just a START (which we want to ignore)
+		mov_fw	t
+		and_lw	0xdf ; ?D_A
+		xor_lw	0x88 ; SMP, !CKE, !P; S, !R_W, !UA, !BF
+		bra_nz	si_if_bad
+
+		; OK, ignore it
+		return
+
+
+		
 
 chkval macro mask, value, label
 		mov_fw	t
-- 
2.30.2