isa: Allow ISA-style drivers on modern systems

Several modern devices, such as PC/104 cards, are expected to run on
modern systems via an ISA bus interface. Since ISA is a legacy interface
for most modern architectures, ISA support should remain disabled in
general. Support for ISA-style drivers should be enabled on a per driver
basis.

To allow ISA-style drivers on modern systems, this patch introduces the
ISA_BUS_API and ISA_BUS Kconfig options. The ISA bus driver will now
build conditionally on the ISA_BUS_API Kconfig option, which defaults to
the legacy ISA Kconfig option. The ISA_BUS Kconfig option allows the
ISA_BUS_API Kconfig option to be selected on architectures which do not
enable ISA (e.g. X86_64).

The ISA_BUS Kconfig option is currently only implemented for X86
architectures. Other architectures may have their own ISA_BUS Kconfig
options added as required.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/isa.h b/include/linux/isa.h
index 5ab85281230b..384ab9b7d79a 100644
--- a/include/linux/isa.h
+++ b/include/linux/isa.h
@@ -22,7 +22,7 @@ struct isa_driver {
 
 #define to_isa_driver(x) container_of((x), struct isa_driver, driver)
 
-#ifdef CONFIG_ISA
+#ifdef CONFIG_ISA_BUS_API
 int isa_register_driver(struct isa_driver *, unsigned int);
 void isa_unregister_driver(struct isa_driver *);
 #else