PERFORCE change 110618 for review

[Warner Losh]

http://perforce.freebsd.org/chv.cgi?CH=110618

Change 110618 by imp at imp_lighthouse on 2006/11/28 08:42:52

	Careful reading of the datasheet shows that we don't have to do
	a complete read when we do a right.  Rather, we just need to start
	*A* read, even if it is for 0 bytes.  The lockout mechanism is
	will release access to the chip.  In fact, we could likely
	get away with not bothering to do this at all, since the very
	next write will stall.  Better safe than sorry until I can get more
	experience.
	
	In addition, careful study of the larger parts shows that the
	16 bit parts > 64KB could have additional bits set in the slave
	address.  Also, it is most significant byte first, not least, so
	fix that while I'm here.

Affected files ...

.. //depot/projects/arm/src/sys/dev/iicbus/icee.c#4 edit

Differences ...

==== //depot/projects/arm/src/sys/dev/iicbus/icee.c#4 (text+ko) ====

@@ -44,7 +44,7 @@
 
 #define	IIC_M_WR	0	/* write operation */
 #define	MAX_RD_SZ	256	/* Largest read size we support */
-#define MAX_WR_SZ	16	/* Largest write size we support */
+#define MAX_WR_SZ	256	/* Largest write size we support */
 
 struct icee_softc {
 	device_t	sc_dev;		/* Myself */
@@ -182,11 +182,12 @@
 			break;
 		case 16:
 			for (i = 0; i < 2; i++)
-				msgs[i].slave = sc->addr;
+				msgs[i].slave = sc->addr |
+				    uio->uio_offset >> 16;
 			msgs[0].len = 2;
 			msgs[1].len = len;
-			addr[0] = uio->uio_offset & 0xff;
-			addr[1] = (uio->uio_offset >> 8) & 0xff;
+			addr[0] = (uio->uio_offset >> 8) & 0xff;
+			addr[1] = uio->uio_offset & 0xff;
 			break;
 		}
 		error = iicbus_transfer(sc->sc_dev, msgs, 2);
@@ -214,7 +215,6 @@
 	uint8_t data[MAX_WR_SZ + 2];
 	struct iic_msg msgs[3] = {
 	     { 0, IIC_M_WR, 0, data },
-	     { 0, IIC_M_WR, 0, data },
 	     { 0, IIC_M_RD, 0, data },
 	};
 
@@ -235,26 +235,23 @@
 			break;
 		switch (sc->type) {
 		case 8:
-			for (i = 0; i < 3; i++)
+			for (i = 0; i < 2; i++)
 				msgs[i].slave = uio->uio_offset >> 8 | sc->addr;
 			msgs[0].len = 1 + len;
-			msgs[1].len = 1;
-			msgs[2].len = 1;
-			msgs[2].buf = data + 1;
+			msgs[1].len = 0;
 			data[0] = uio->uio_offset & 0xff;
 			break;
 		case 16:
-			for (i = 0; i < 3; i++)
-				msgs[i].slave = sc->addr;
+			for (i = 0; i < 2; i++)
+				msgs[i].slave = sc->addr |
+				    uio->uio_offset >> 16;
 			msgs[0].len = 2 + len;
-			msgs[1].len = 2;
-			msgs[2].len = 1;
-			msgs[2].buf = data + 2;
-			data[0] = uio->uio_offset & 0xff;
-			data[1] = (uio->uio_offset >> 8) & 0xff;
+			msgs[1].len = 0;
+			data[0] = (uio->uio_offset >> 8) & 0xff;
+			data[1] = uio->uio_offset & 0xff;
 			break;
 		}
-		error = iicbus_transfer(sc->sc_dev, msgs, 3);
+		error = iicbus_transfer(sc->sc_dev, msgs, 2);
 		if (error)
 			break;
 	}