From a5cd9e84f4cc92e9ffe36968558b73de8e49d55d Mon Sep 17 00:00:00 2001
From: nwhitehorn <nwhitehorn@FreeBSD.org>
Date: Sat, 5 Jun 2010 17:49:40 +0000
Subject: Utilize the Keywest I2C combined mode for messages with repeated
 starts.

---
 sys/powerpc/powermac/kiic.c | 65 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 57 insertions(+), 8 deletions(-)

(limited to 'sys/powerpc/powermac')

diff --git a/sys/powerpc/powermac/kiic.c b/sys/powerpc/powermac/kiic.c
index 1f246e7..459d20e 100644
--- a/sys/powerpc/powermac/kiic.c
+++ b/sys/powerpc/powermac/kiic.c
@@ -107,6 +107,7 @@ struct kiic_softc {
 	u_int 			 sc_flags;
 	u_char			*sc_data;
 	int 			 sc_resid;
+	uint16_t		 sc_i2c_base;
 	device_t 		 sc_iicbus;
 };
 
@@ -114,6 +115,7 @@ static int 	kiic_probe(device_t dev);
 static int 	kiic_attach(device_t dev);
 static void 	kiic_writereg(struct kiic_softc *sc, u_int, u_int);
 static u_int 	kiic_readreg(struct kiic_softc *, u_int);
+static void 	kiic_setport(struct kiic_softc *, u_int);
 static void 	kiic_setmode(struct kiic_softc *, u_int);
 static void 	kiic_setspeed(struct kiic_softc *, u_int);
 static void 	kiic_intr(void *xsc);
@@ -196,12 +198,25 @@ kiic_attach(device_t self)
 	 * underneath them.  Some have a single 'iicbus' child with the
 	 * devices underneath that.  Sort this out, and make sure that the
 	 * OFW I2C layer has the correct node.
+	 *
+	 * Note: the I2C children of the Uninorth bridges have two ports.
+	 *  In general, the port is designated in the 9th bit of the I2C
+	 *  address. However, for kiic devices with children attached below
+	 *  an i2c-bus node, the port is indicated in the 'reg' property
+	 *  of the i2c-bus node.
 	 */
 
-	sc->sc_node = OF_child(node);
-	if (OF_getprop(sc->sc_node,"name",name,sizeof(name)) > 0) {
-		if (strcmp(name,"i2c-bus") != 0)
+	sc->sc_node = node;
+
+	node = OF_child(node);
+	if (OF_getprop(node, "name", name, sizeof(name)) > 0) {
+		if (strcmp(name,"i2c-bus") == 0) {
+			phandle_t reg;
+			if (OF_getprop(node, "reg", &reg, sizeof(reg)) > 0)
+				sc->sc_i2c_base = reg << 8;
+
 			sc->sc_node = node;
+		}
 	}
 
 	mtx_init(&sc->sc_mutex, "kiic", NULL, MTX_DEF);
@@ -211,8 +226,8 @@ kiic_attach(device_t self)
 	bus_setup_intr(self, sc->sc_irq, INTR_TYPE_MISC | INTR_MPSAFE, NULL,
 	    kiic_intr, sc, &sc->sc_ih);
 
+	kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
 	kiic_writereg(sc, STATUS, 0);
-	kiic_writereg(sc, ISR, 0);
 	kiic_writereg(sc, IER, 0);
 
 	kiic_setmode(sc, I2C_STDMODE);
@@ -252,6 +267,18 @@ kiic_setmode(struct kiic_softc *sc, u_int mode)
 }
 
 static void
+kiic_setport(struct kiic_softc *sc, u_int port)
+{
+	u_int x;
+
+	KASSERT(port == 1 || port == 0, ("bad port"));
+	x = kiic_readreg(sc, MODE);
+	x &= ~I2C_PORT;
+	x |= (port << 4);
+	kiic_writereg(sc, MODE, x);
+}
+
+static void
 kiic_setspeed(struct kiic_softc *sc, u_int speed)
 {
 	u_int x;
@@ -294,7 +321,8 @@ kiic_intr(void *xsc)
 				*sc->sc_data++ = kiic_readreg(sc, DATA);
 				sc->sc_resid--;
 			}
-
+			if (sc->sc_resid == 0)  /* done */
+				kiic_writereg(sc, CONTROL, 0);
 		} else {
 			if (sc->sc_resid == 0) {
 				x = kiic_readreg(sc, CONTROL);
@@ -322,10 +350,12 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
 {
 	struct kiic_softc *sc;
 	int i, x, timo, err;
-	uint8_t addr;
+	uint16_t addr;
+	uint8_t subaddr;
 
 	sc = device_get_softc(dev);
 	timo = 100;
+	subaddr = 0;
 
 	mtx_lock(&sc->sc_mutex);
 
@@ -339,7 +369,23 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
 		
 	sc->sc_flags = I2C_BUSY;
 
+	/* Clear pending interrupts, and reset controller */
+	kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
+	kiic_writereg(sc, STATUS, 0);
+
 	for (i = 0; i < nmsgs; i++) {
+		if (msgs[i].flags & IIC_M_NOSTOP) {
+			if (msgs[i+1].flags & IIC_M_RD)
+				kiic_setmode(sc, I2C_COMBMODE);
+			else
+				kiic_setmode(sc, I2C_STDSUBMODE);
+			KASSERT(msgs[i].len == 1, ("oversize I2C message"));
+			subaddr = msgs[i].buf[0];
+			i++;
+		} else {
+			kiic_setmode(sc, I2C_STDMODE);
+		}
+
 		sc->sc_data = msgs[i].buf;
 		sc->sc_resid = msgs[i].len;
 		sc->sc_flags = I2C_BUSY;
@@ -352,8 +398,11 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
 			addr |= 1;
 		}
 
-		kiic_writereg(sc, ADDR, addr);
-		kiic_writereg(sc, SUBADDR, 0x04);
+		addr |= sc->sc_i2c_base;
+
+		kiic_setport(sc, (addr & 0x100) >> 8);
+		kiic_writereg(sc, ADDR, addr & 0xff);
+		kiic_writereg(sc, SUBADDR, subaddr);
 
 		x = kiic_readreg(sc, CONTROL) | I2C_CT_ADDR;
 		kiic_writereg(sc, CONTROL, x);
-- 
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