[PATCH linux dev-4.10 v2] arm: dts: aspeed: Add IR35221 instances to dev tree

[Brad Bishop]

> On May 24, 2017, at 9:16 PM, Joel Stanley <joel at jms.id.au> wrote:
> 
> On Thu, May 25, 2017 at 4:32 AM, Brad Bishop
> <bradleyb at fuzziesquirrel.com> wrote:
>> 
>>> On May 24, 2017, at 2:20 AM, Joel Stanley <joel at jms.id.au> wrote:
>>> 
>>> On Wed, May 24, 2017 at 10:58 AM, Joel Stanley <joel at jms.id.au> wrote:
>>>> On Sat, May 20, 2017 at 3:34 AM, Christopher Bostic
>>>> <cbostic at linux.vnet.ibm.com> wrote:
>>>>> Add IR35221 to i2c4 and i2c5 buses.
>>>> 
>>>> This is similar to the patch that I sent on the 2nd.
>>>> 
>>>> I took your patch as it adds the device at 0x71 which I did not know about.
>>>> 
>>> 
>>> This breaks userspace, as userspace assumes it can access the i2c
>>> devices through /dev/i2c-x.
>>> 
>> 
>> Joel, or anyone able to answer…
>> 
>> Do you know which application?  I wasn’t aware of any applications using i2c-dev...
> 
> The one I noticed was vrm-control.sh.
> 
>> Can we simply remove i2c-dev from the config?
> 
> We could, but that would break other bits of the p9 userspace.
> 
> Taking a look a the root filesystem, we have the following
> applications that use the /dev/i2c interfaces:
> 
> $ grep -rl i2cset *
> usr/sbin/i2cset
> usr/bin/avsbus-disable.sh
> usr/bin/avsbus-workaround.sh
> usr/bin/avsbus-enable.sh
> usr/bin/vrm-control.sh
> usr/bin/vcs_on.sh
> usr/bin/ucd_disable_vcs.sh
> usr/bin/vcs_off.sh
> 

Thanks Joel.  I had forgotten about these.

I’m not sure how to handle this.  We obviously still need to run these workarounds,
but we also need the regulator temperatures.

The only thing I can think of is exposing what these scripts need via sysfs attributes.

Is there any alternative?

> grep -rl i2cget *
> usr/sbin/i2cget
> usr/bin/vrm-control.sh
> 
> Cheers,
> 
> Joel