Revert the introduction of iobase in struct uart_bas. Both the SAB82532

and the Z8530 drivers used the I/O address as a quick and dirty way to
determine which channel they operated on, but formalizing this by
introducing iobase is not a solution. How for example would a driver
know which channel it controls for a multi-channel UART that only has a
single I/O range?

Instead, add an explicit field, called chan, to struct uart_bas that
holds the channel within a device, or 0 otherwise. The chan field is
initialized both by the system device probing (i.e. a system console)
or it is passed down to uart_bus_probe() by any of the bus front-ends.
As such, it impacts all platforms and bus drivers and makes it a rather
large commit.

Remove the use of iobase in uart_cpu_eqres() for pc98. It is expected
that platforms have the capability to compare tag and handle pairs for
equality; as to determine whether two pairs access the same device or
not. The use of iobase for pc98 makes it impossible to formalize this
and turn it into a real newbus function later. This commit reverts
uart_cpu_eqres() for pc98 to an unimplemented function. It has to be
reimplemented using only the tag and handle fields in struct uart_bas.

Rewrite the SAB82532 and Z8530 drivers to use the chan field in struct
uart_bas. Remove the IS_CHANNEL_A and IS_CHANNEL_B macros. We don't
need to abstract anything anymore.

Discussed with: nyan
Tested on: i386, ia64, sparc64

1 files changed, 4 insertions, 5 deletions

diff --git a/sys/dev/uart/uart_core.c b/sys/dev/uart/uart_core.c
index 501156f..18141c2 100644
--- a/sys/dev/uart/uart_core.c
+++ b/sys/dev/uart/uart_core.c
@@ -221,7 +221,7 @@ uart_intr(void *arg)
 }
 
 int
-uart_bus_probe(device_t dev, int regshft, int rclk, int rid)
+uart_bus_probe(device_t dev, int regshft, int rclk, int rid, int chan)
 {
 	struct uart_softc *sc;
 	struct uart_devinfo *sysdev;
@@ -267,14 +267,15 @@ uart_bus_probe(device_t dev, int regshft, int rclk, int rid)
 	 * accordingly. In general, you don't want to permanently disrupt
 	 * console I/O.
 	 */
-	sc->sc_bas.iobase = rman_get_start(sc->sc_rres);
 	sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
 	sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);
+	sc->sc_bas.chan = chan;
 	sc->sc_bas.regshft = regshft;
 	sc->sc_bas.rclk = (rclk == 0) ? sc->sc_class->uc_rclk : rclk;
 
 	SLIST_FOREACH(sysdev, &uart_sysdevs, next) {
-		if (uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
+		if (chan == sysdev->bas.chan &&
+		    uart_cpu_eqres(&sc->sc_bas, &sysdev->bas)) {
 			/* XXX check if ops matches class. */
 			sc->sc_sysdev = sysdev;
 			break;
@@ -324,8 +325,6 @@ uart_bus_attach(device_t dev)
 	    0, ~0, sc->sc_class->uc_range, RF_ACTIVE);
 	if (sc->sc_rres == NULL)
 		return (ENXIO);
-
-	sc->sc_bas.iobase = rman_get_start(sc->sc_rres);
 	sc->sc_bas.bsh = rman_get_bushandle(sc->sc_rres);
 	sc->sc_bas.bst = rman_get_bustag(sc->sc_rres);