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* [PATCH v3 0/4] Allow ISA-style drivers on modern systems
@ 2016-05-23 23:13 William Breathitt Gray
  2016-05-23 23:13 ` [PATCH v3 1/4] isa: " William Breathitt Gray
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: William Breathitt Gray @ 2016-05-23 23:13 UTC (permalink / raw)
  To: gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r,
	akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b
  Cc: x86-DgEjT+Ai2ygdnm+yROfE0A, linux-next-u79uwXL29TY76Z2rM5mHXA,
	linux-gpio-u79uwXL29TY76Z2rM5mHXA,
	linux-iio-u79uwXL29TY76Z2rM5mHXA,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA,
	linux-watchdog-u79uwXL29TY76Z2rM5mHXA,
	sfr-3FnU+UHB4dNDw9hX6IcOSA, William Breathitt Gray

Changes in v3:
  - Remove redundant X86 dependency from the X86 ISA_BUS Kconfig option

Changes in v2:
  - Adjusted preprocessor compilation conditional in include/linux/isa.h
    to use CONFIG_ISA_BUS_API in order to link the correct ISA bus
    driver function definitions when available
  - Move ISA_BUS_API Kconfig option to arch/Kconfig, thus making it
    available to all architectures instead of just X86
  - X86 ISA_BUS Kconfig option should be disabled by default; ISA
    devices typically do not have a way to be probed, so users should
    be required to explicitly enable ISA bus driver support, lest a
    selected driver be loaded with the misguided expectation of a safe
    hardware probe

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 patchset 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
option added as required.

An earlier attempt to allow the ISA bus driver to build for X86_64 took
an inappropriate approach resulting in legacy ISA drivers becoming
enabled unconditionally on untested and unsupported architectures.
Commit 51e68d055cba ("x86 isa: add back X86_32 dependency on
CONFIG_ISA"), added to restrict the ISA bus driver to only X86_32,
causes several drivers intended for X86_64 to be restricted to X86_32 as
well.

This patchset replaces the ISA Kconfig option dependency of several
drivers to ISA_BUS_API, so that they may build for X86_64 as intended.
The respective drivers are as follows:
    * ACCES 104-IDIO-16 GPIO driver
    * ACCES 104-IDI-48 GPIO driver
    * ACCES 104-DIO-48E GPIO driver
    * Apex Embedded Systems STX104 DAC driver
    * WinSystems EBC-C384 watchdog timer driver
    * WinSystems WS16C48 GPIO driver

William Breathitt Gray (4):
  isa: Allow ISA-style drivers on modern systems
  gpio: Allow PC/104 devices on X86_64
  iio: stx104: Allow build for X86_64
  watchdog: ebc-c384_wdt: Allow build for X86_64

 arch/Kconfig             |  3 +++
 arch/x86/Kconfig         | 10 ++++++++++
 drivers/base/Makefile    |  2 +-
 drivers/gpio/Kconfig     |  8 ++++----
 drivers/iio/dac/Kconfig  |  2 +-
 drivers/watchdog/Kconfig |  2 +-
 include/linux/isa.h      |  2 +-
 7 files changed, 21 insertions(+), 8 deletions(-)

-- 
2.7.3

^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH v3 1/4] isa: Allow ISA-style drivers on modern systems
  2016-05-23 23:13 [PATCH v3 0/4] Allow ISA-style drivers on modern systems William Breathitt Gray
@ 2016-05-23 23:13 ` William Breathitt Gray
  2016-05-23 23:54   ` Guenter Roeck
  2016-05-23 23:13 ` [PATCH v3 2/4] gpio: Allow PC/104 devices on X86_64 William Breathitt Gray
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 6+ messages in thread
From: William Breathitt Gray @ 2016-05-23 23:13 UTC (permalink / raw)
  To: gregkh, akpm
  Cc: x86, linux-next, linux-gpio, linux-iio, linux-kernel,
	linux-watchdog, sfr, William Breathitt Gray, Linus Torvalds

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.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 arch/Kconfig          |  3 +++
 arch/x86/Kconfig      | 10 ++++++++++
 drivers/base/Makefile |  2 +-
 include/linux/isa.h   |  2 +-
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index b16e74e..9d9942f 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -598,6 +598,9 @@ config HAVE_STACK_VALIDATION
 	  Architecture supports the 'objtool check' host tool command, which
 	  performs compile-time stack metadata validation.
 
+config ISA_BUS_API
+	def_bool ISA
+
 #
 # ABI hall of shame
 #
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 0a7b885..a5338a6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2439,6 +2439,16 @@ config PCI_CNB20LE_QUIRK
 
 source "drivers/pci/Kconfig"
 
+config ISA_BUS
+	bool "ISA-style bus support on modern systems" if EXPERT
+	default n
+	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 6b2a84e..2609ba2 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 5ab8528..384ab9b 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
-- 
2.7.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH v3 2/4] gpio: Allow PC/104 devices on X86_64
  2016-05-23 23:13 [PATCH v3 0/4] Allow ISA-style drivers on modern systems William Breathitt Gray
  2016-05-23 23:13 ` [PATCH v3 1/4] isa: " William Breathitt Gray
@ 2016-05-23 23:13 ` William Breathitt Gray
  2016-05-23 23:14 ` [PATCH v3 3/4] iio: stx104: Allow build for X86_64 William Breathitt Gray
  2016-05-23 23:14 ` [PATCH v3 4/4] watchdog: ebc-c384_wdt: " William Breathitt Gray
  3 siblings, 0 replies; 6+ messages in thread
From: William Breathitt Gray @ 2016-05-23 23:13 UTC (permalink / raw)
  To: gregkh, akpm
  Cc: x86, linux-next, linux-gpio, linux-iio, linux-kernel,
	linux-watchdog, sfr, William Breathitt Gray, Guenter Roeck,
	Linus Walleij

With the introduction of the ISA_BUS_API Kconfig option, ISA-style
drivers may be built for X86_64 architectures. This patch changes the
ISA Kconfig option dependency of the PC/104 drivers to ISA_BUS_API, thus
allowing them to build for X86_64 as they are expected to.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 drivers/gpio/Kconfig | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 48da857..dc6da77 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -530,7 +530,7 @@ menu "Port-mapped I/O GPIO drivers"
 
 config GPIO_104_DIO_48E
 	tristate "ACCES 104-DIO-48E GPIO support"
-	depends on ISA
+	depends on ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-DIO-48E series (104-DIO-48E,
@@ -540,7 +540,7 @@ config GPIO_104_DIO_48E
 
 config GPIO_104_IDIO_16
 	tristate "ACCES 104-IDIO-16 GPIO support"
-	depends on ISA
+	depends on ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-IDIO-16 family (104-IDIO-16,
@@ -551,7 +551,7 @@ config GPIO_104_IDIO_16
 
 config GPIO_104_IDI_48
 	tristate "ACCES 104-IDI-48 GPIO support"
-	depends on ISA
+	depends on ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the ACCES 104-IDI-48 family (104-IDI-48A,
@@ -627,7 +627,7 @@ config GPIO_TS5500
 
 config GPIO_WS16C48
 	tristate "WinSystems WS16C48 GPIO support"
-	depends on ISA
+	depends on ISA_BUS_API
 	select GPIOLIB_IRQCHIP
 	help
 	  Enables GPIO support for the WinSystems WS16C48. The base port
-- 
2.7.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH v3 3/4] iio: stx104: Allow build for X86_64
  2016-05-23 23:13 [PATCH v3 0/4] Allow ISA-style drivers on modern systems William Breathitt Gray
  2016-05-23 23:13 ` [PATCH v3 1/4] isa: " William Breathitt Gray
  2016-05-23 23:13 ` [PATCH v3 2/4] gpio: Allow PC/104 devices on X86_64 William Breathitt Gray
@ 2016-05-23 23:14 ` William Breathitt Gray
  2016-05-23 23:14 ` [PATCH v3 4/4] watchdog: ebc-c384_wdt: " William Breathitt Gray
  3 siblings, 0 replies; 6+ messages in thread
From: William Breathitt Gray @ 2016-05-23 23:14 UTC (permalink / raw)
  To: gregkh, akpm
  Cc: x86, linux-next, linux-gpio, linux-iio, linux-kernel,
	linux-watchdog, sfr, William Breathitt Gray, Hartmut Knaack,
	Lars-Peter Clausen, Peter Meerwald-Stadler, Jonathan Cameron

With the introduction of the ISA_BUS_API Kconfig option, ISA-style
drivers may be built for X86_64 architectures. This patch changes the
ISA Kconfig option dependency of the Apex Embedded Systems STX104 DAC
driver to ISA_BUS_API, thus allowing it to build for X86_64 as it is
expected to.

Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 drivers/iio/dac/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index e63b957..315442f 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -247,7 +247,7 @@ config MCP4922
 
 config STX104
 	tristate "Apex Embedded Systems STX104 DAC driver"
-	depends on X86 && ISA
+	depends on ISA_BUS_API
 	help
 	  Say yes here to build support for the 2-channel DAC on the Apex
 	  Embedded Systems STX104 integrated analog PC/104 card. The base port
-- 
2.7.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH v3 4/4] watchdog: ebc-c384_wdt: Allow build for X86_64
  2016-05-23 23:13 [PATCH v3 0/4] Allow ISA-style drivers on modern systems William Breathitt Gray
                   ` (2 preceding siblings ...)
  2016-05-23 23:14 ` [PATCH v3 3/4] iio: stx104: Allow build for X86_64 William Breathitt Gray
@ 2016-05-23 23:14 ` William Breathitt Gray
  3 siblings, 0 replies; 6+ messages in thread
From: William Breathitt Gray @ 2016-05-23 23:14 UTC (permalink / raw)
  To: gregkh, akpm
  Cc: x86, linux-next, linux-gpio, linux-iio, linux-kernel,
	linux-watchdog, sfr, William Breathitt Gray, Guenter Roeck,
	Wim Van Sebroeck

With the introduction of the ISA_BUS_API Kconfig option, ISA-style
drivers may be built for X86_64 architectures. This patch changes the
ISA Kconfig option dependency of the WinSystems EBC-C384 watchdog timer
driver to ISA_BUS_API, thus allowing it to build for X86_64 as it is
expected to.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
---
 drivers/watchdog/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b54f26c..3938e2d 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -746,7 +746,7 @@ config ALIM7101_WDT
 
 config EBC_C384_WDT
 	tristate "WinSystems EBC-C384 Watchdog Timer"
-	depends on X86 && ISA
+	depends on ISA_BUS_API
 	select WATCHDOG_CORE
 	help
 	  Enables watchdog timer support for the watchdog timer on the
-- 
2.7.3

^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH v3 1/4] isa: Allow ISA-style drivers on modern systems
  2016-05-23 23:13 ` [PATCH v3 1/4] isa: " William Breathitt Gray
@ 2016-05-23 23:54   ` Guenter Roeck
  0 siblings, 0 replies; 6+ messages in thread
From: Guenter Roeck @ 2016-05-23 23:54 UTC (permalink / raw)
  To: William Breathitt Gray
  Cc: gregkh, akpm, x86, linux-next, linux-gpio, linux-iio,
	linux-kernel, linux-watchdog, sfr, Linus Torvalds

On Mon, May 23, 2016 at 07:13:31PM -0400, William Breathitt Gray wrote:
> 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.
> 
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
> ---
>  arch/Kconfig          |  3 +++
>  arch/x86/Kconfig      | 10 ++++++++++
>  drivers/base/Makefile |  2 +-
>  include/linux/isa.h   |  2 +-
>  4 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/Kconfig b/arch/Kconfig
> index b16e74e..9d9942f 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -598,6 +598,9 @@ config HAVE_STACK_VALIDATION
>  	  Architecture supports the 'objtool check' host tool command, which
>  	  performs compile-time stack metadata validation.
>  
> +config ISA_BUS_API
> +	def_bool ISA
> +
>  #
>  # ABI hall of shame
>  #
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 0a7b885..a5338a6 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2439,6 +2439,16 @@ config PCI_CNB20LE_QUIRK
>  
>  source "drivers/pci/Kconfig"
>  
> +config ISA_BUS
> +	bool "ISA-style bus support on modern systems" if EXPERT
> +	default n

I don't think an explicit "default n" is necessary.

> +	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 6b2a84e..2609ba2 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 5ab8528..384ab9b 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
> -- 
> 2.7.3
> 
> --
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-05-23 23:54 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-05-23 23:13 [PATCH v3 0/4] Allow ISA-style drivers on modern systems William Breathitt Gray
2016-05-23 23:13 ` [PATCH v3 1/4] isa: " William Breathitt Gray
2016-05-23 23:54   ` Guenter Roeck
2016-05-23 23:13 ` [PATCH v3 2/4] gpio: Allow PC/104 devices on X86_64 William Breathitt Gray
2016-05-23 23:14 ` [PATCH v3 3/4] iio: stx104: Allow build for X86_64 William Breathitt Gray
2016-05-23 23:14 ` [PATCH v3 4/4] watchdog: ebc-c384_wdt: " William Breathitt Gray

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