work in progress.

- add power button, and number of gpes to acpictl
- only turn on the sci if it's off (as per spec)
- only intrenable sci if successful,
- clear pm1sts before calling power button fn.
- use configured pm1ctl values for S5 state (soft power off)
- read *all* of the pm1 banked register to prevent read tearing.
(bug: not locked; bug: need to apply to other banked registers.)

Reference: /n/atom/patch/applied2013/devacpicfg
Date: Tue Oct 22 08:15:14 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/devacpi.c	Tue Oct 22 08:15:11 2013
+++ /sys/src/nix/k10/devacpi.c	Tue Oct 22 08:15:12 2013
@@ -46,7 +46,7 @@
 
 	Qdir = 0,
 	Qctl,
-	Qtbl,
+	Qevent,
 };
 
 static Cmdtab ctls[] = {
@@ -58,11 +58,11 @@
 static Dirtab acpidir[]={
 	".",		{Qdir, 0, QTDIR},	0,	DMDIR|0555,
 	"acpictl",	{Qctl},			0,	0666,
-	"acpitbl",	{Qtbl},			0,	0444,
+	"acpievent",	{Qevent},	0,	0444,
 };
 
 static	Gpe*	gpes;	/* General purpose events */
-static	int	ngpes;
+static	int	ngpe;
 static	Aconf	aconf;
 
 static int
@@ -149,32 +149,47 @@
 	return r;
 }
 
+/*
+ * we must read the register group *as a whole*
+ */
 static uint
 getpm1ctl(void)
 {
 	return getbanked(fadt.pm1acntblk, fadt.pm1bcntblk, fadt.pm1cntlen);
 }
 
-static void
-setpm1sts(uint v)
-{
-	DBG("acpi: setpm1sts %#ux\n", v);
-	setbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen/2, v);
-}
-
 static uint
 getpm1sts(void)
 {
-	return getbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen/2);
+	return getbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen) & 0xffff;
 }
 
 static uint
 getpm1en(void)
 {
-	int sz;
+	return getbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen)>>16;
+}
+
+static void
+setpm1en(uint v)
+{
+	u32int r;
 
-	sz = fadt.pm1evtlen/2;
-	return getbanked(fadt.pm1aevtblk+sz, fadt.pm1bevtblk+sz, sz);
+	r = getbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen);
+	r &= 0xffff;
+	setbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen, r | v<<16);
+}
+
+static void
+setpm1sts(uint v)
+{
+	u32int r;
+
+	DBG("acpi: setpm1sts %#ux\n", v);
+
+	r = getbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen);
+	r &= 0xffff0000;
+	setbanked(fadt.pm1aevtblk, fadt.pm1bevtblk, fadt.pm1evtlen, r | v);
 }
 
 static int
@@ -209,14 +224,16 @@
 }
 
 static void
-setpm1ctl(uint u)
+setpm1ctl(uint a, uint b)
 {
-	setbanked(fadt.pm1acntblk, fadt.pm1bcntblk, fadt.pm1cntlen, u);
+	setbanked(fadt.pm1acntblk, 0, fadt.pm1cntlen, a);
+	setbanked(0, fadt.pm1bcntblk, fadt.pm1cntlen, b);
 }
 
 void
 acpipoweroff(void)
 {
+	uint *t;
 	enum {
 		Go	= 1<<13,
 		Sstate	= 1<<10,
@@ -226,7 +243,8 @@
 	/*
 	 * bug: we're assuming that this is a fixed function
 	 */
-	setpm1ctl(7*Sstate| Go);
+	t = acpicfg.sval[5];
+	setpm1ctl(t[0]*Sstate | Go, t[1]*Sstate | Go);
 }
 
 void
@@ -269,7 +287,7 @@
 	int i;
 	uint sts, en;
 
-	for(i = 0; i < ngpes; i++)
+	for(i = 0; i < ngpe; i++)
 		if(getgpests(i)){
 			iprint("gpe %d on\n", i);
  			en = getgpeen(i);
@@ -283,11 +301,13 @@
 	en = getpm1en();
 	iprint("acpinitr: pm1sts %#ux pm1en %#ux\n", sts, en);
 	if(sts&en){
-		iprint("acpinitr: have enabled events\n");
+		iprint("acpinitr: enabled: %#ux\n", sts&en);
 	}
-	setpm1sts(sts);	
-	if(sts&Epowerbtn)
+	setpm1sts(sts);
+	if(sts&Epowerbtn){
 		aconf.powerbutton();
+	//	qiwrite(event.q, "power");
+	}
 }
 
 static void
@@ -297,8 +317,8 @@
 
 	n0 = fadt.gpe0blklen/2;
 	n1 = fadt.gpe1blklen/2;
-	ngpes = n0 + n1;
-	gpes = mallocz(sizeof(Gpe) * ngpes, 1);
+	ngpe = n0 + n1;
+	gpes = mallocz(sizeof(Gpe) * ngpe, 1);
 	for(i = 0; i < n0; i++){
 		gpes[i].nb = i;
 		gpes[i].stsbit = i&7;
@@ -306,14 +326,14 @@
 		gpes[i].enbit = (n0 + i)&7;
 		gpes[i].enio = fadt.gpe0blk + ((n0 + i)>>3);
 	}
-	for(i = 0; i + n0 < ngpes; i++){
+	for(i = 0; i + n0 < ngpe; i++){
 		gpes[i + n0].nb = fadt.gp1base + i;
 		gpes[i + n0].stsbit = i&7;
 		gpes[i + n0].stsio = fadt.gpe1blk + (i>>3);
 		gpes[i + n0].enbit = (n1 + i)&7;
 		gpes[i + n0].enio = fadt.gpe1blk + ((n1 + i)>>3);
 	}
-	for(i = 0; i < ngpes; i++){
+	for(i = 0; i < ngpe; i++){
 		setgpeen(i, 0);
 		clrgpests(i);
 	}
@@ -354,18 +374,25 @@
 	 * This starts ACPI, which requires we handle
 	 * power mgmt events ourselves.
 	 */
-	print("acpi: enable interrupt\n");
-	outb(fadt.smicmd, fadt.acpienable);
-	for(i = 0;; i++){
-		if(i == 10){
-			print("acpi: failed to enable\n");
-			return;
+	if(fadt.sciint == 0)
+		return;
+	if((getpm1ctl() & Pm1SciEn) == 0){
+		outb(fadt.smicmd, fadt.acpienable);
+		for(i = 0;; i++){
+			if(i == 10){
+				print("acpi: failed to enable\n");
+				outb(fadt.smicmd, fadt.acpidisable);
+				return;
+			}
+			if(getpm1ctl() & Pm1SciEn)
+				break;
 		}
-		if(getpm1ctl() & Pm1SciEn)
-			break;
 	}
-	if(fadt.sciint != 0)
-		intrenable(fadt.sciint, acpiintr, 0, BUSUNKNOWN, "acpi");
+
+	print("acpi: enable interrupt\n");
+	setpm1sts(getpm1sts());
+	setpm1en(Epowerbtn);
+	intrenable(fadt.sciint, acpiintr, 0, BUSUNKNOWN, "acpi");
 }
 
 static Chan*
@@ -420,10 +447,12 @@
 			s = "??";
 		else
 			s = pwrbuttab[i].name;
-		seprint(p, e, "powerbutton %s\n", s);
+		p = seprint(p, e, "powerbutton %s\n", s);
+		p = seprint(p, e, "ngpe %d\n", ngpe);
+		USED(p);
 		return readstr(off, a, n, buf);
 		
-	case Qtbl:
+	case Qevent:
 		s = "";
 		return readstr(off, a, n, s);
 	}
@@ -450,7 +479,7 @@
 	switch(ct->index){
 	case CMgpe:
 		i = strtoul(cb->f[1], nil, 0);
-		if(i >= ngpes)
+		if(i >= ngpe)
 			error("gpe out of range");
 		kstrdup(&gpes[i].obj, cb->f[2]);
 		DBG("gpe %d %s\n", i, gpes[i].obj);