From: Doug Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
To: addy ke <addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Cc: "Wolfram Sang" <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>,
"Max Schwarz"
<max.schwarz-BGeptl67XyCzQB+pC5nmwQ@public.gmane.org>,
"Heiko Stübner" <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>,
"Olof Johansson" <olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org>,
"linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
"Eddie Cai" <cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"Jianqun Xu" <xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"Tao Huang" <huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
Chris <zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
姚智情 <yzq-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"han jiang" <hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"Kever Yang" <kever.yang-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"Lin Huang" <hl-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
晓腾王 <caesar.wang-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
"Shunqian Zheng"
<zhengsq-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Subject: Re: [PATCH] i2c: rk3x: adjust the LOW divison based on characteristics of SCL
Date: Wed, 24 Sep 2014 21:36:38 -0700 [thread overview]
Message-ID: <CAD=FV=Uuk1zBYn4NgcpDSHVfKeyw3MONO7roUNVSPSDDEyD=8Q@mail.gmail.com> (raw)
In-Reply-To: <5423765B.8000706-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Addy,
On Wed, Sep 24, 2014 at 6:56 PM, addy ke <addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org> wrote:
> In my measurement,all paramter but "Data hold time" are match the characteristics of SCL bus line.
> the measured value is 0.928us("data hold time on RK3X" ~= "the low period / 2")
> but the maximum value described in table is 0.9us
>
> About "Data hold time", there are described in I2C specification:
> - for CBUS compatible masters for I2C-bus deivices
> - the maximum data hold time has only be met if the device does not stretch the LOW period of the SCL signal.
>
> I have tested on RK3288-Pinky board, there are no error.
> But I don't known whether this paramter will affect i2c communications.
I'll have to spend more time tomorrow to really understand this, but
if changing the code to bias towards slightly longer "high" times
instead of "low" times helps fix it then that's fine with me.
next prev parent reply other threads:[~2014-09-25 4:36 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-24 1:55 [PATCH] i2c: rk3x: adjust the LOW divison based on characteristics of SCL Addy Ke
2014-09-24 4:10 ` Doug Anderson
2014-09-24 8:23 ` addy ke
[not found] ` <54227F93.7000507-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
2014-09-24 17:13 ` Doug Anderson
2014-09-25 1:56 ` addy ke
[not found] ` <5423765B.8000706-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
2014-09-25 4:36 ` Doug Anderson [this message]
[not found] ` <CAD=FV=Uuk1zBYn4NgcpDSHVfKeyw3MONO7roUNVSPSDDEyD=8Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-09-25 21:52 ` Doug Anderson
[not found] ` <CAD=FV=UkAcR8b+T_Dvoy9STDfzyC8QVSawihoHLYyHFJ6bfXxQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-09-26 1:40 ` addy ke
2014-09-26 2:08 ` Doug Anderson
2014-09-26 2:40 ` addy ke
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAD=FV=Uuk1zBYn4NgcpDSHVfKeyw3MONO7roUNVSPSDDEyD=8Q@mail.gmail.com' \
--to=dianders-f7+t8e8rja9g9huczpvpmw@public.gmane.org \
--cc=addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=caesar.wang-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org \
--cc=hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=hl-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=kever.yang-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=max.schwarz-BGeptl67XyCzQB+pC5nmwQ@public.gmane.org \
--cc=olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org \
--cc=wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org \
--cc=xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=yzq-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=zhengsq-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
--cc=zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).