Subject: Re: [PATCH] drivers/misc: introduce Freescale Data Collection Manager driver

From: Tabi Timur-B04825 <[email-masked]>
Date: Mon, 1 Aug 2011 23:58:00 +0000

Mark Brown wrote:
> On Mon, Aug 01, 2011 at 04:48:54PM -0500, Timur Tabi wrote:
>> The Data Collection Manager (DCM) is a feature of the FPGA on some Freescale
>> PowerPC reference boards that can read temperature, current, and voltage
>> settings from the sensors on those boards.  This driver exposes the DCM via a
>> sysfs interface (/sys/devices/platform/fsl-ocm.0).
>
> This sounds like it should be a hwmon driver.

I didn't see any way to interface the hardware to the hwmon layer in a 
manner that provides the information that our customers went using this 
hardware.

>> The DCM collects and tallies data over a period of time in the background,
>> without utilizing any resources on the host (CPU, memory, etc).  The data is
>> summarized and made available when data collection stops.  This allows power
>> consumption to be measured while the host is performing some tasks (usually
>> a benchmark).
>
> Though this is a bit odd for the subsystem I don't think it's too far
> out of what other hwmon chips can do, some of them do have longer term
> stats than just instantaneous readings.

Can you show an example or some documentation?  I couldn't find anything 
remotely like that.  I don't even see anything that lets me start/stop 
monitoring of sensors.

-- 
Timur Tabi
Linux kernel developer at Freescale