On Wed, Feb 10, 2016 at 06:55:45PM +0000, Jonathan Cameron wrote: >On 10/02/16 02:19, William Breathitt Gray wrote: >> On Tue, Feb 09, 2016 at 10:37:09PM +0000, Jonathan Cameron wrote: >>> My only real question is on the naming of the module parameter. >>> Is it the equivalent of the io address that a load of ISA >>> radio drivers seem to use? (fed to me by grepping isa_register_driver) >>> If so perhaps that's the 'standard' name as much as one exists for this? >> >> Yes, you noted correctly that the stx104_base module parameter fulfills >> the same function as the io module parameter used in many of the radio >> drivers: it's an array holding the io port address of each device. >> However, I find "io" to be a rather vague module parameter name, so I've >> decided to use the more apt "stx104_base" name for my array of base >> addresses. >> >> As you've probably noticed, there are few ISA drivers existing in the >> kernel baseline currently, so not much of a standard is set yet. I'm all >> right with renaming the module parameter if you have a preference, just >> as long as the name is more informative than simply "io." >> >> For what it's worth, this driver is part of a series of PC/104 drivers >> I've been submitting to various subsystems (in the hopes of improving >> the lack of PC/104 support in the baseline Linux kernel); see >> drivers/gpio/gpio-104-idio-16.c and drivers/gpio/gpio-104-idi-48.c for >> example. I have thus far been following the convention of naming the >> base address module parameter as "modname_base," where "modname" is the >> respective module name. >I've been trying to work out if IO ports is a generic enough ISA term >to take the view that anyone using an ISA card should know about it... >I certainly know the I/O space approach to interacting with PCI cards is >well understood in people working with shall we say 'dumb' PCI hardware. > >I guess I don't really care all that much on this though - just nice to >be consistent / general when possible. I believe that port-mapped I/O is ubiquitous enough in the industry that anyone with an ISA card will understand the term; in fact, I can't recall any PC/104 card datasheet I've encountered without a chapter section devoted to "I/O port address" configuration. The ISA drivers in the sound subsystem use "port" as the module parameter name for the I/O port base address of the respective sound device. Notice also how there are module parameters such as "midi_port" which represent the I/O port address of various registers on the device. "I/O port address" does not necessarily mean the base address of the device, but simply a port address (typically pointing to a particular register). For this reason, I prefer the more specific name "base" to indicate the I/O port base address of the device from which to derive the register addresses. Thinking it over again, I want to submit a version 3 of this patch which will rename "stx104_base" to the more general "base" name; the "stx104_" prefix is overly verbose for a module parameter since the user should already know the module he/she is configuring. Hopefully, by using a more general name, there will also arise a more consistent way of configuring the I/O port base addresses among other PC/104 and ISA drivers via the "base" module parameter. Are there any other changes I should include in version 3? On an unrelated note, I may write a patch in the future to add support for the 16-channel ADC on the STX104. Should this support be added into this existing iio/dac/stx104.c file, or into a new iio/adc/stx104.c file? William Breathitt Gray -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
