[PATCH v2] base: isa: Remove X86_32 dependency

From: William Breathitt Gray
Date: Fri Jan 22 2016 - 11:28:21 EST

Many motherboards utilize a LPC to ISA bridge in order to decode
ISA-style port-mapped I/O addresses. This is particularly true for
embedded motherboards supporting the PC/104 bus (a bus specification
derived from ISA).

These motherboards are now commonly running 64-bit x86 processors. The
X86_32 dependency should be removed from the ISA bus configuration
option in order to support these newer motherboards.

A new config option, CONFIG_ISA_BUS, is introduced to allow for the
compilation of the ISA bus driver independent of the CONFIG_ISA option.
Devices which communicate via ISA-compatible buses can now be supported
independent of the dependencies of the CONFIG_ISA option.

Signed-off-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
arch/x86/Kconfig | 6 ++++++
drivers/base/Makefile | 2 +-
include/linux/isa.h | 2 +-
3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4a10ba9..c85073d 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2443,10 +2443,16 @@ config ISA_DMA_API
Enables ISA-style DMA support for devices requiring such controllers.
If unsure, say Y.

+config ISA_BUS
+ bool "ISA bus support"
+ help
+ Enables ISA bus support for devices requiring such controllers.
if X86_32

config ISA
bool "ISA support"
+ depends on ISA_BUS
Find out whether you have ISA slots on your motherboard. ISA is the
name of a bus system, i.e. the way the CPU talks to the other stuff
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 6b2a84e..4ebfb81 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -10,7 +10,7 @@ obj-$(CONFIG_DMA_CMA) += dma-contiguous.o
obj-y += power/
obj-$(CONFIG_HAS_DMA) += dma-mapping.o
obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
-obj-$(CONFIG_ISA) += isa.o
+obj-$(CONFIG_ISA_BUS) += isa.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
obj-$(CONFIG_NUMA) += node.o
diff --git a/include/linux/isa.h b/include/linux/isa.h
index b0270e3..2a02862 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
int isa_register_driver(struct isa_driver *, unsigned int);
void isa_unregister_driver(struct isa_driver *);