Re: [PATCH v3 1/1] alix2: supplement driver to include GPIO button support

[Philip Prindeville <philipp@redfish-solutions.com>]

On 1/25/12 3:57 PM, Andrew Morton wrote:
> On Mon, 23 Jan 2012 12:56:29 -0700
> Philip Prindeville <philipp@redfish-solutions.com> wrote:
> 
>> From: "Philip A. Prindeville" <philipp@redfish-solutions.com>
>>
>> GPIO 24 is used in reference designs as a soft-reset button, and
>> the alix2 is no exception. Add it as a gpio-button.
>>
>> Use symbolic values to describe BIOS addresses.
>>
>> Record the model number.
>>
>> Redux: address Andres' review comments; make the model number exported;
>> add support for DMI detection of the board and manufacturer; change
>> detection return type to bool; add comment explaining that the model 
>> number is used by downstream drivers to detect if we have RFKILL GPIO
>> line to mini-PCIe slots (alix 6 only).
>>
>>
>> ...
>>
>>  arch/x86/platform/geode/alix.c |   80 +++++++++++++++++++++++++++++++++++++--
>>  1 files changed, 75 insertions(+), 5 deletions(-)
>>
>> --- a/arch/x86/platform/geode/alix.c
>> +++ b/arch/x86/platform/geode/alix.c
>>
>> ...
>>
>> @@ -24,14 +25,55 @@
>>  #include <linux/leds.h>
>>  #include <linux/platform_device.h>
>>  #include <linux/gpio.h>
>> +#include <linux/input.h>
>> +#include <linux/gpio_keys.h>
>> +#include <linux/dmi.h>
>>  
>>  #include <asm/geode.h>
>>  
>> +#define BIOS_SIGNATURE_TINYBIOS		0xf0000
>> +#define BIOS_SIGNATURE_COREBOOT		0x500
>> +#define BIOS_REGION_SIZE		0x10000
>> +
>> +/*
>> + * the 6F2 has an RFKILL GPIO line to the mini-PCIe slots that isn't
>> + * present on other Alix boards. Wifi drivers can use this symbol to
>> + * detect if it's available.
>> + */
>> +int alix_model;
>> +EXPORT_SYMBOL(alix_model);
> 
> This is odd.  There are no references to this from outside this file
> and it's hard to see how a wireless driver could use this - any such
> driver would have to load this module on *all* machines (even non-x86)
> simply to resolve this symbol.

It's for an out-of-tree driver that's only ever built for Alix hardware.

Since it's only 4 bytes and one exported symbol, I figured it was acceptable...

I can remove it, resubmit, and use a patch locally in my tree if that's preferable.

-Philip

> 
>>
>> ...
>>