work in progress.

- correct error in converting flags to trigger values.  §5.2.12.5, 5-50 (acpi 5.0)
- provide a new structure to store acpi-private configuration information.
- get the values to program into pm1actl and pm1bctl to go to sleep from \_Sn_.
- properly probe the power button, including evaluting _STA for present &
decoding, and if so, run _INI if it exists

Reference: /n/atom/patch/applied2013/acpicfg
Date: Tue Oct 22 08:08:50 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/nix/k10/acpi.c	Tue Oct 22 08:08:45 2013
+++ /sys/src/nix/k10/acpi.c	Tue Oct 22 08:08:46 2013
@@ -35,6 +35,7 @@
 static	int	ntblmap;			/* successfully mapped tables */
 static	Tbl	*tblmap[64];
 	Fadt	fadt;
+	Acpicfg	acpicfg;
 
 static int
 checksum(void *v, int n)
@@ -292,7 +293,7 @@
 int
 flagstotrigger(int bustype, int flags)
 {
-	switch((flags>>3) & 3){
+	switch((flags>>2) & 3){
 	case 1:
 		return TMedge;
 	case 3:
@@ -648,6 +649,7 @@
 	/* add identity mapped legacy isa interrupts */
 	for(i=0; i<16; i++)
 		addirq(i, BusISA, 0, i, 0);
+
 	DBG("acpiinit: %d maches\n", nmach);
 }
 
@@ -959,6 +961,100 @@
 	print("\n");
 }
 
+int
+checkpnpid(void *dot, char *pnpid)
+{
+	char *id;
+	void *p, *x;
+
+	if(dot == nil)
+		return -1;
+	id = nil;
+	if((x = amlwalk(dot, "_HID")) != nil)
+		if((p = amlval(x)) != nil)
+			id = eisaid(p);
+	if(id == nil)
+		return -1;
+	return strcmp(id, pnpid);
+}
+
+enum {
+	Present	= 1<<0,
+	Decode	= 1<<1,
+	Funct	= 1<<3,
+	Staok	= Present | Funct,
+};
+
+int
+staok(void *dot)
+{
+	int b;
+	void *p, *x;
+
+	if((x = amlwalk(dot, "_STA")) == nil)
+		return 0;
+	if(amleval(x, "", &p) != 0)
+		return 0;
+	b = amlint(p);
+	return b & Staok;
+}
+
+static int
+evalini(void *dot)
+{
+	int b;
+	void *p, *x;
+
+	b = staok(dot);
+	if((b & Present) == 0)
+		return -1;
+	if((x = amlwalk(dot, "_INI")) != nil){
+		if(amleval(x, "", &p) == 0)
+			print("eval _INI → %V\n", p);
+	}
+	return 0;
+}
+
+int
+cfgpwerb(void)
+{
+	void *dot;
+
+	dot = amlwalk(amlroot, "\\_SB_.PWRB");
+	if(checkpnpid(dot, "PNP0C0C") != 0)
+		return 0;
+//	print("PWRB %V\n", dot);
+	if(evalini(dot) == -1){
+		print("PWRB evalini fails\n");
+		return 0;
+	}
+	return 1;
+}
+
+static void
+cfgsleep(void)
+{
+	char buf[16];
+	uint *t, i;
+	void **v;
+
+	/* default soft off values */
+	t = acpicfg.sval[5];
+	t[0] = 7;
+	t[1] = 0;
+
+	/* look for the proper ones */
+	for(i = 0; i < 6; i++){
+		t = acpicfg.sval[i];
+		snprint(buf, sizeof buf, "\\_S%d_", i);
+		v = amlval(amlwalk(amlroot, buf));
+		if(v != nil && amltag(v) == 'p' && amllen(v) == 4){
+			t[0] = amlint(v[0]);
+			t[1] = amlint(v[1]);
+		}
+	}
+}
+
 #define acpiinit(x)	mpsinit(x)	/* temporary hack */
 void
 acpiinit(int maxmach)
@@ -978,6 +1074,9 @@
 	parsetables(&dat);
 	if(fadt.smicmd != 0)
 		iapcbootarch();
+
+	cfgpwerb();
+	cfgsleep();
 
 	/* free the AML interpreter */
 	amlexit();
--- /sys/src/nix/k10/acpi.h	Tue Oct 22 08:08:46 2013
+++ /sys/src/nix/k10/acpi.h	Tue Oct 22 08:08:47 2013
@@ -2,6 +2,8 @@
 typedef	struct	Gas	Gas;
 typedef	struct	Tbl	Tbl;
 
+typedef	struct	Acpicfg	Acpicfg;
+
 /*
  * Header for ACPI description tables
  */
@@ -87,6 +89,11 @@
 };
 #pragma	varargck	type	"G"	Gas*
 
+struct Acpicfg {
+	uint	sval[6][2];		/* p1a.ctl, p1b.ctl */
+};
+
 Tbl*	acpigettbl(void*);
 
 extern	Fadt	fadt;
+extern	Acpicfg	acpicfg;