[9fans] rpi emmc

[erik quanstrom <quanstro@quanstro.net>]

in diffing bls' version and sources, i see some significant differences, but
it's not clear which one is more up-to-date.

anyone?

- erik

----

; 9diff emmc.c
/n/sources/plan9/sys/src/9/bcm/emmc.c:178,184 - emmc.c:178,188
  static int
  datadone(void*)
  {
- 	return emmc.datadone;
+ 	int i;
+
+ 	u32int *r = (u32int*)EMMCREGS;
+ 	i = r[Interrupt];
+ 	return i & (Datadone|Err);
  }

  static int
/n/sources/plan9/sys/src/9/bcm/emmc.c:310,318 - emmc.c:314,322
  	if((c & Respmask) == Resp48busy){
  		WR(Irpten, Datadone|Err);
  		tsleep(&emmc.r, datadone, 0, 3000);
- 		i = emmc.datadone;
- 		emmc.datadone = 0;
  		WR(Irpten, 0);
+ 		emmc.datadone = 0;
+ 		i = r[Interrupt];
  		if((i & Datadone) == 0)
  			print("emmcio: no Datadone after CMD%d\n", cmd);
  		if(i & Err)
/n/sources/plan9/sys/src/9/bcm/emmc.c:380,390 - emmc.c:384,396
  			&r[Data], buf, len);
  	if(dmawait(DmaChanEmmc) < 0)
  		error(Eio);
+ 	if(!write)
+ 		cachedinvse(buf, len);
  	WR(Irpten, Datadone|Err);
  	tsleep(&emmc.r, datadone, 0, 3000);
- 	i = emmc.datadone;
- 	emmc.datadone = 0;
  	WR(Irpten, 0);
+ 	emmc.datadone = 0;
+ 	i = r[Interrupt];
  	if((i & Datadone) == 0){
  		print("emmcio: %d timeout intr %ux stat %ux\n",
  			write, i, r[Status]);
/n/sources/plan9/sys/src/9/bcm/emmc.c:407,419 - emmc.c:413,423
  mmcinterrupt(Ureg*, void*)
  {
  	u32int *r;
- 	int i;
-
  	r = (u32int*)EMMCREGS;
- 	i = r[Interrupt];
- 	r[Interrupt] = i & (Datadone|Err);
- 	emmc.datadone = i;
- 	wakeup(&emmc.r);
+ 	if(r[Interrupt]&(Datadone|Err)){
+ 		WR(Irpten, 0);
+ 		wakeup(&emmc.r);
+ 	}
  }

  SDio sdio = {