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, 2 insertions, 2 deletions

diff --git a/sys/dev/uart/uart.h b/sys/dev/uart/uart.h
index ba17e89..5de4d42 100644
--- a/sys/dev/uart/uart.h
+++ b/sys/dev/uart/uart.h
@@ -36,11 +36,11 @@
  * other timing related computations.
  */
 struct uart_bas {
-	bus_addr_t iobase;
 	bus_space_tag_t bst;
 	bus_space_handle_t bsh;
-	u_int	regshft;
+	u_int	chan;
 	u_int	rclk;
+	u_int	regshft;
 };
 
 #define	uart_regofs(bas, reg)		((reg) << (bas)->regshft)