Get the AST2500 SCUE0/E4 value using kernel device driver?

Get the AST2500 SCUE0/E4 value using kernel device driver?

[Yong Li]

[-- Attachment #1: Type: text/plain, Size: 305 bytes --]

Hi All,

 

Just want to know if there is any existing device driver provides the
interface to get the SCUE0/E4 register values on AST2500?

 

If no, I would like to know if there is any examples/similar drivers for
reference?  By the way, the two registers are used for the uptime

 

Thanks,

Yong

 


[-- Attachment #2: Type: text/html, Size: 2340 bytes --]

Re: Get the AST2500 SCUE0/E4 value using kernel device driver?

[Andrew Jeffery]

On Wed, 15 May 2019, at 17:12, Yong Li wrote:
> Hi All,
> 
> 
> Just want to know if there is any existing device driver provides the 
> interface to get the SCUE0/E4 register values on AST2500?
> 
> 
> If no, I would like to know if there is any examples/similar drivers 
> for reference? By the way, the two registers are used for the uptime

I'm not aware of any, but I'm interested in what you're trying to measure.
Are you after something that can't be satisfied by CLOCK_MONOTONIC
and friends for clock_gettime()? Or is that what you're wanting to drive?

Andrew

> 
> 
> Thanks,
> 
> Yong
> 
>

RE: Get the AST2500 SCUE0/E4 value using kernel device driver?

[Yong Li]

HI Andrew,

Thanks for the reply.

I want to get the time from the very beginning of the AC power on, including
the time spent on u-boot. 

My understanding is that the clock_gettime only return the Linux up time, it
cannot get the delay in bootloader(u-boot).

For example, the time from power on to the console login is about 65
seconds,
u-boot spends 25 seconds, and Linux boot needs another 40 seconds.

I want to get the total time: 65 seconds.  

Thanks,
Yong
-----Original Message-----
From: Andrew Jeffery <andrew@aj.id.au> 
Sent: Friday, May 17, 2019 7:17 AM
To: Yong Li <yong.b.li@linux.intel.com>; 'OpenBMC Maillist'
<openbmc@lists.ozlabs.org>
Cc: Li, Yong B <yong.b.li@intel.com>
Subject: Re: Get the AST2500 SCUE0/E4 value using kernel device driver? 



On Wed, 15 May 2019, at 17:12, Yong Li wrote:
> Hi All,
> 
> 
> Just want to know if there is any existing device driver provides the 
> interface to get the SCUE0/E4 register values on AST2500?
> 
> 
> If no, I would like to know if there is any examples/similar drivers 
> for reference? By the way, the two registers are used for the uptime

I'm not aware of any, but I'm interested in what you're trying to measure.
Are you after something that can't be satisfied by CLOCK_MONOTONIC and
friends for clock_gettime()? Or is that what you're wanting to drive?

Andrew

> 
> 
> Thanks,
> 
> Yong
> 
>