Re: [PATCH v2 001/001] gpio: AMD CS5535/CS5536 GPIO driver

From: Tobias MÃller
Date: Tue Jun 02 2009 - 04:15:01 EST


2009/6/2 Jordan Crouse <jordan@xxxxxxxxxxxxxxxxx>:
> Andres Salomon wrote:
>> As far as Tobias's driver, one major difference between our drivers is
>> that mine doesn't grab the entire PCI device. This is because other
>> drivers (ie, the MFGPT driver) will want to share the PCI device.
>
> Also SMBUS. In fact, they *must* share the PCI device if they all want to
> play well together, so that alone would probably push us toward Andre's
> patch, once it gets clean.

I had SMBUS and my driver tested in parallel and there I didn't found any
problems. But I would be fine if we would use Andre's patch. I haven't know
about, so that's why I tried my own. :)

I see some other problem's on Andre's patch:
- He allows the use of PIN 23 which is reserved
- No special handling is done for 28, which is a GPIO, but
serves as Power Button as well
- OUT_AUX1/OUT_AUX2 should be disabled by default
if pin is configured as in output
- IN_AUX should be disabled by default is pin is
configured as in input

And, if I request a GPIO by userspace via sysfs, on my system it's an
input pin by default. So my driver initializes a GPIO as an input by default.
But I don't know if this is default or system specific. I didn't found anything
about this in the gpio docs.

So maybe we should decide whether we take Andre's or my approach
and then adjust it.

Tobias
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