From: dianders@chromium.org (Doug Anderson)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2] i2c: rk3x: fix divisor calculation for SCL frequency
Date: Sun, 7 Sep 2014 21:15:16 -0700 [thread overview]
Message-ID: <CAD=FV=WY=wS6P5f4BVfoyy8EWvrn9Mzh=wkOXBiEiJyQ-HNM=Q@mail.gmail.com> (raw)
In-Reply-To: <1410147505-5930-1-git-send-email-addy.ke@rock-chips.com>
Addy,
On Sun, Sep 7, 2014 at 8:38 PM, Addy Ke <addy.ke@rock-chips.com> wrote:
> I2C_CLKDIV register descripted in the previous version of
> RK3x chip manual is incorrect. Plus 1 is required.
>
> The correct formula:
> - T(SCL_HIGH) = T(PCLK) * (CLKDIVH + 1) * 8
> - T(SCL_LOW) = T(PCLK) * (CLKDIVL + 1) * 8
> - (SCL Divsor) = 8 * ((CLKDIVL + 1) + (CLKDIVH + 1))
> - SCL = PCLK / (CLK Divsor)
>
> It will be updated to the latest version of chip manual.
>
> Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
> ---
> changes since v1:
> - make it more cleaner, suggested by Doug Anderson
>
> drivers/i2c/busses/i2c-rk3x.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
Reviewed-by: Doug Anderson <dianders@chromium.org>
next prev parent reply other threads:[~2014-09-08 4:15 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-05 2:32 [PATCH] i2c: rk3x: fix divisor calculation for SCL frequency Addy Ke
2014-09-05 4:31 ` Doug Anderson
2014-09-05 10:17 ` addy ke
2014-09-05 15:20 ` Doug Anderson
2014-09-08 3:38 ` [PATCH v2] " Addy Ke
2014-09-08 4:15 ` Doug Anderson [this message]
2014-09-20 12:19 ` Wolfram Sang
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=WY=wS6P5f4BVfoyy8EWvrn9Mzh=wkOXBiEiJyQ-HNM=Q@mail.gmail.com' \
--to=dianders@chromium.org \
--cc=linux-arm-kernel@lists.infradead.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).