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, 14 insertions, 10 deletions

diff --git a/sys/dev/uart/uart_dev_z8530.c b/sys/dev/uart/uart_dev_z8530.c
index 30d8ed8..25bdca7 100644
--- a/sys/dev/uart/uart_dev_z8530.c
+++ b/sys/dev/uart/uart_dev_z8530.c
@@ -42,9 +42,6 @@ __FBSDID("$FreeBSD$");
 
 #define	DEFAULT_RCLK	307200
 
-#define	IS_CHANNEL_A(bas)	(((bas)->iobase & 7) != 0)
-#define	IS_CHANNEL_B(bas)	(((bas)->iobase & 7) == 0)
-
 /* Multiplexed I/O. */
 static __inline void
 uart_setmreg(struct uart_bas *bas, int reg, int val)
@@ -144,14 +141,22 @@ static int
 z8530_setup(struct uart_bas *bas, int baudrate, int databits, int stopbits,
     int parity)
 {
-	uint8_t tpc;
+	uint8_t mic, tpc;
 
 	if (bas->rclk == 0)
 		bas->rclk = DEFAULT_RCLK;
 
 	/* Assume we don't need to perform a full hardware reset. */
-	uart_setmreg(bas, WR_MIC, ((IS_CHANNEL_A(bas)) ? MIC_CRA : MIC_CRB) |
-	    MIC_MIE | MIC_NV);
+	mic = MIC_MIE | MIC_NV;
+	switch (bas->chan) {
+	case 1:
+		mic |= MIC_CRA;
+		break;
+	case 2:
+		mic |= MIC_CRB;
+		break;
+	}
+	uart_setmreg(bas, WR_MIC, mic);
 	uart_barrier(bas);
 	/* Set clock sources and enable BRG. */
 	uart_setmreg(bas, WR_CMC, CMC_RC_BRG | CMC_TC_BRG);
@@ -433,17 +438,16 @@ static int
 z8530_bus_probe(struct uart_softc *sc)
 {
 	char buf[80];
-	const char *ch;
 	int error;
+	char ch;
 
 	error = z8530_probe(&sc->sc_bas);
 	if (error)
 		return (error);
 
-	/* Assume the address range is naturally aligned. */
-	ch = IS_CHANNEL_A(&sc->sc_bas) ? "A" : "B";
+	ch = sc->sc_bas.chan - 1 + 'A';
 
-	snprintf(buf, sizeof(buf), "z8530, channel %s", ch);
+	snprintf(buf, sizeof(buf), "z8530, channel %c", ch);
 	device_set_desc_copy(sc->sc_dev, buf);
 	return (0);
 }