pc, pc64: provide access to embedded controller with #P/ec file

1 files changed, 138 insertions, 0 deletions

diff --git a/sys/src/9/pc/ec.c b/sys/src/9/pc/ec.c
new file mode 100644
index 000000000..c42356af7
--- /dev/null
+++ b/sys/src/9/pc/ec.c
@@ -0,0 +1,138 @@
+/*
+ * embedded controller (usually at ports 0x66/0x62)
+ */
+#include	"u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+#include	"../port/error.h"
+
+enum {
+	/* registers */
+	EC_SC	= 0,
+	EC_DATA,
+
+	/* Embedded Controller Status, EC_SC (R) */
+	OBF	= 1<<0,
+	IBF	= 1<<1,
+	CMD	= 1<<3,
+	BURST	= 1<<4,
+	SCI_EVT	= 1<<5,
+	SMI_EVT	= 1<<6,
+
+	/* Embedded Controller Command Set */
+	RD_EC	= 0x80,
+	WR_EC	= 0x81,
+	BE_EC	= 0x82,
+	BD_EC	= 0x83,
+	QR_EC	= 0x84,
+};
+
+static struct {
+	Lock;
+	int	init;
+	int	port[2];	/* EC_SC and EC_DATA */
+} ec;
+
+static uchar
+ecrr(int reg)
+{
+	return inb(ec.port[reg]);
+}
+static void
+ecwr(int reg, uchar val)
+{
+	outb(ec.port[reg], val);
+}
+
+static int
+ecwait(uchar mask, uchar val)
+{
+	int i, s;
+
+	s = 0;
+	for(i=0; i<1000; i++){
+		s = ecrr(EC_SC);
+		if((s & mask) == val)
+			return 0;
+		delay(1);
+	}
+	print("ec: wait timeout status=%x pc=%#p\n", s, getcallerpc(&mask));
+	return -1;
+}
+
+int
+ecinit(int cmdport, int dataport)
+{
+	print("ec: cmd %X, data %X\n", cmdport, dataport);
+
+	if(ioalloc(cmdport, 1, 0, "ec.sc") < 0){
+		print("ec: cant allocate cmd port %X\n", cmdport);
+		return -1;
+	}
+	if(ioalloc(dataport, 1, 0, "ec.data") < 0){
+		print("ec: cant allocate data port %X\n", dataport);
+		iofree(cmdport);
+		return -1;
+	}
+
+	lock(&ec);
+	ec.port[EC_SC] = cmdport;
+	ec.port[EC_DATA] = dataport;
+	ec.init = 1;
+	unlock(&ec);
+
+	return 0;
+}
+
+int
+ecread(uchar addr)
+{
+	int r;
+
+	r = -1;
+	lock(&ec);
+	if(!ec.init)
+		goto out;
+	if(ecwait(BURST|CMD, 0))
+		goto out;
+	ecwr(EC_SC, RD_EC);
+	if(ecwait(IBF, 0))
+		goto out;
+	ecwr(EC_DATA, addr);
+	if(ecwait(OBF, OBF))
+		goto out;
+	r = ecrr(EC_DATA);
+	ecwait(OBF, 0);
+out:
+	unlock(&ec);
+	return r;
+}
+
+int
+ecwrite(uchar addr, uchar val)
+{
+	int r;
+
+	r = -1;
+	lock(&ec);
+	if(!ec.init)
+		goto out;
+	if(ecwait(BURST|CMD, 0))
+		goto out;
+	ecwr(EC_SC, WR_EC);
+	if(ecwait(IBF, 0))
+		goto out;
+	ecwr(EC_DATA, addr);
+	if(ecwait(IBF, 0))
+		goto out;
+	ecwr(EC_DATA, val);
+	if(ecwait(IBF, 0))
+		goto out;
+	r = 0;
+out:
+	unlock(&ec);
+	return r;
+}