[PATCH] staging: comedi: allow ISA and PC/104 drivers on non-ISA systems

[H Hartley Sweeten]

On Thursday, July 25, 2013 3:43 AM, Ian Abbott wrote:
> On 2013-07-24 19:24, H Hartley Sweeten wrote:
>> Embedded systems with a PC/104 bus might have a configuration that
>> does not have ISA enabled. This creates a problem in Comedi where
>> the PC/104 drivers cannot be enabled.
>>
>> Introduce a Kconfig option to allow enabling the Comedi ISA and
>> PC/104 drivers if ISA is disabled.
>>
>> Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
>> Cc: Ian Abbott <abbotti at mev.co.uk>
>> Cc: Greg Kroah-Hartman <gregkh at linuxfondation.org>
>> ---
>>   drivers/staging/comedi/Kconfig | 13 ++++++++++++-
>>   1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig
>> index 01782fc..4a5dc4c 100644
>> --- a/drivers/staging/comedi/Kconfig
>> +++ b/drivers/staging/comedi/Kconfig
>> @@ -98,9 +98,20 @@ config COMEDI_SKEL
>>
>>   endif # COMEDI_MISC_DRIVERS
>>
>> +if !ISA
>> +
>> +config COMEDI_ENABLE_ISA
>> +	bool "Enable Comedi ISA and PC/104 drivers on non-ISA systems"
>> +	---help---
>> +	  Many of the Comedi PC/104 drivers work on embeded systems that
>> +	  might not have the ISA option enabled. Select this option to
>> +	  enable Comedi ISA and PC/104 drivers on these systems.
>> +
>> +endif # !ISA
>> +
>>   menuconfig COMEDI_ISA_DRIVERS
>>   	bool "Comedi ISA and PC/104 drivers"
>> -	depends on ISA
>> +	depends on ISA || COMEDI_ENABLE_ISA
>>   	---help---
>>   	  Enable comedi ISA and PC/104 drivers to be built
>>
>>
>
> I know there are one or two PC/104-Plus CPU boards with 64-bit 
> processors that have a PC/104 ISA bus, but I don't know how well PC/104 
> ISA boards work on such systems when run in 64-bit mode.  Is it worth 
> worrying about them?

I don't see any technical reasons why they would not work. The 8255 module
is technically a legacy driver but it's used by a number of comedi PCI drivers.

There are even a number of baseboards available that provide a passive ISA
backplane for PC/104 boards. Here's a link to one:

http://www.douglas.com/hardware/pcbs/pc104/bxde63104.html

This one provides 2 PCI slots as well as 1 ISA slot for PC/104-Plus systems.

http://www.douglas.com/hardware/pcbs/pc104/bxde104163265.html

> If you just want the option to build-test the ISA drivers, there is a 
> COMPILE_TEST configuration option that could be checked, e.g.:
> 
> menuconfig COMEDI_ISA_DRIVERS
>	bool "Comedi ISA and PC/104 drivers"
>	depends on ISA || COMPILE_TEST
>    	---help---
>    	  Enable comedi ISA and PC/104 drivers to be built

Build testing is one of my desires. But, if the drivers might be useful
for PC/104-Plus CPU boards we might as well allow the option.

Regards,
Hartley