From 3a4955111ad46a022f05b51f91306d864f989625 Mon Sep 17 00:00:00 2001
From: William Breathitt Gray <vilhelm.gray@gmail.com>
Date: Fri, 27 May 2016 18:08:27 -0400
Subject: [PATCH] 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>
---
arch/Kconfig | 3 +++
arch/x86/Kconfig | 9 +++++++++
drivers/base/Makefile | 2 +-
include/linux/isa.h | 2 +-
4 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index d794384a0404..e9734796531f 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -606,6 +606,9 @@ config HAVE_ARCH_HASH
file which provides platform-specific implementations of some
functions in <linux/hash.h> or fs/namei.c.
+config ISA_BUS_API
+ def_bool ISA
+
#
# ABI hall of shame
#
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0a7b885964ba..d9a94da0c29f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2439,6 +2439,15 @@ config PCI_CNB20LE_QUIRK
source "drivers/pci/Kconfig"
+config ISA_BUS
+ bool "ISA-style bus support on modern systems" if EXPERT
+ select ISA_BUS_API
+ help
+ Enables ISA-style drivers on modern systems. This is necessary to
+ support PC/104 devices on X86_64 platforms.
+
+ If unsure, say N.
+
# x86_64 have no ISA slots, but can have ISA-style DMA.
config ISA_DMA_API
bool "ISA-style DMA support" if (X86_64 && EXPERT)
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 6b2a84e7f2be..2609ba20b396 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-$(CONFIG_ISA_BUS_API) += isa.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
obj-$(CONFIG_NUMA) += node.o
obj-$(CONFIG_MEMORY_HOTPLUG_SPARSE) += memory.o
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
--
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