Add support for the PCA9547 I2C mux to pcamux(4). In comparison to

the PCA954[68], this is a mux instead of a switch and can only have
one active channel at a time.  On the bright side, we treat switches
like a mux, so only the bits have to be set a little bit differently.

ok kettenis@

3 files changed, 29 insertions, 15 deletions

diff --git a/share/man/man4/iic.4 b/share/man/man4/iic.4
index e1318dca8e4..bcbbedb2d23 100644
--- a/share/man/man4/iic.4
+++ b/share/man/man4/iic.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: iic.4,v 1.114 2020/10/01 07:37:47 jmc Exp $
+.\"	$OpenBSD: iic.4,v 1.115 2020/11/13 10:14:53 patrick Exp $
 .\"
 .\" Copyright (c) 2004, 2006 Alexander Yurchenko <grange@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: October 1 2020 $
+.Dd $Mdocdate: November 13 2020 $
 .Dt IIC 4
 .Os
 .Sh NAME
@@ -220,7 +220,7 @@ Philips PCA955[4567] GPIO controller
 .It Xr pcaled 4
 Philips PCA9532/9552 GPIO LED dimmer
 .It Xr pcamux 4
-Philips PCA954[68] I2C switch
+Philips PCA954[678] I2C switch/mux
 .It Xr pcfadc 4
 Philips PCF8591 temperature sensor
 .It Xr pcfrtc 4
diff --git a/share/man/man4/pcamux.4 b/share/man/man4/pcamux.4
index 82eda7cc9f2..a03729fb0c3 100644
--- a/share/man/man4/pcamux.4
+++ b/share/man/man4/pcamux.4
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: pcamux.4,v 1.3 2020/09/29 13:59:22 patrick Exp $
+.\"	$OpenBSD: pcamux.4,v 1.4 2020/11/13 10:14:53 patrick Exp $
 .\"
 .\" Copyright (c) 2020 Mark Kettenis <kettenis@openbsd.org>
 .\"
@@ -14,20 +14,20 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: September 29 2020 $
+.Dd $Mdocdate: November 13 2020 $
 .Dt PCAMUX 4
 .Os
 .Sh NAME
 .Nm pcamux
-.Nd Philips PCA954[68] I2C switch
+.Nd Philips PCA954[678] I2C switch/mux
 .Sh SYNOPSIS
 .Cd "pcamux* at iic?"
 .Cd "iic* at pcamux?"
 .Sh DESCRIPTION
 The
 .Nm
-driver provides support for the Philips PCA954[68] I2C switch,
-which is used with the
+driver provides support for the Philips PCA954[68] I2C switch
+and Philips PCA9547 I2C mux, which is used with the
 .Xr iic 4
 framework.
 .Sh SEE ALSO
diff --git a/sys/dev/i2c/pca9548.c b/sys/dev/i2c/pca9548.c
index f4320a9f985..2709a05e79c 100644
--- a/sys/dev/i2c/pca9548.c
+++ b/sys/dev/i2c/pca9548.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pca9548.c,v 1.3 2020/09/29 13:59:22 patrick Exp $	*/
+/*	$OpenBSD: pca9548.c,v 1.4 2020/11/13 10:14:52 patrick Exp $	*/
 
 /*
  * Copyright (c) 2020 Mark Kettenis
@@ -28,8 +28,6 @@
 #include <dev/ofw/openfirm.h>
 #include <dev/ofw/ofw_misc.h>
 
-#define PCA9546_NUM_CHANNELS	4
-#define PCA9548_NUM_CHANNELS	8
 #define PCAMUX_MAX_CHANNELS	8
 
 struct pcamux_bus {
@@ -44,12 +42,15 @@ struct pcamux_softc {
 	struct device		sc_dev;
 	i2c_tag_t		sc_tag;
 	i2c_addr_t		sc_addr;
-	
+
 	int			sc_node;
 	int			sc_channel;
 	int			sc_nchannel;
 	struct pcamux_bus	sc_bus[PCAMUX_MAX_CHANNELS];
 	struct rwlock		sc_lock;
+
+	int			sc_switch;
+	int			sc_enable;
 };
 
 int	pcamux_match(struct device *, void *, void *);
@@ -75,6 +76,7 @@ pcamux_match(struct device *parent, void *match, void *aux)
 	struct i2c_attach_args *ia = aux;
 
 	if (strcmp(ia->ia_name, "nxp,pca9546") == 0 ||
+	    strcmp(ia->ia_name, "nxp,pca9547") == 0 ||
 	    strcmp(ia->ia_name, "nxp,pca9548") == 0)
 		return (1);
 	return (0);
@@ -94,10 +96,16 @@ pcamux_attach(struct device *parent, struct device *self, void *aux)
 	sc->sc_channel = -1;	/* unknown */
 	rw_init(&sc->sc_lock, sc->sc_dev.dv_xname);
 
-	if (strcmp(ia->ia_name, "nxp,pca9546") == 0)
+	if (strcmp(ia->ia_name, "nxp,pca9546") == 0) {
+		sc->sc_switch = 1;
 		sc->sc_nchannel = 4;
-	else if (strcmp(ia->ia_name, "nxp,pca9548") == 0)
+	} else if (strcmp(ia->ia_name, "nxp,pca9547") == 0) {
+		sc->sc_enable = 1 << 3;
+		sc->sc_nchannel = 8;
+	} else if (strcmp(ia->ia_name, "nxp,pca9548") == 0) {
+		sc->sc_switch = 1;
 		sc->sc_nchannel = 8;
+	}
 
 	printf("\n");
 
@@ -146,7 +154,13 @@ pcamux_set_channel(struct pcamux_softc *sc, int channel, int flags)
 	if (sc->sc_channel == channel)
 		return 0;
 
-	data = (channel == -1) ? 0 : (1 << channel);
+	data = 0;
+	if (channel != -1) {
+		if (sc->sc_switch)
+			data = 1 << channel;
+		else
+			data = sc->sc_enable | channel;
+	}
 	error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
 	    sc->sc_addr, NULL, 0, &data, sizeof data, flags);