From: Sascha Hauer <s.hauer@pengutronix.de>
To: Eddie Huang <eddie.huang@mediatek.com>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
"Wolfram Sang" <wsa@the-dreams.de>,
"Doug Anderson" <dianders@chromium.org>,
"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>,
"David Box" <david.e.box@linux.intel.com>,
"Lee Jones" <lee.jones@linaro.org>,
"Jean Delvare" <jdelvare@suse.de>,
"Xudong Chen (陈旭东)" <Xudong.Chen@mediatek.com>,
"Boris BREZILLON" <boris.brezillon@free-electrons.com>,
"Pawel Moll" <pawel.moll@arm.com>,
"Liguo Zhang (张立国)" <Liguo.Zhang@mediatek.com>,
"Wei Yan" <sledge.yanwei@huawei.com>,
"Bjorn Andersson" <bjorn.andersson@sonymobile.com>,
"Uwe Kleine-Konig" <u.kleine-koenig@pengutronix.de>,
"Neelesh Gupta" <neelegup@linux.vnet.ibm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"Arnd Bergmann" <arnd@arndb.de>,
"Ian Campbell" <ijc+devicetree@hellion.org.uk>,
"Beniamino Galvani" <b.galvani@gmail.com>,
"Rob Herring" <robh+dt@kernel.org>,
"linux-mediatek@lists.infradead.org"
<linux-mediatek@lists.infradead.org>,
"Matthias Brugger" <matthias.bgg@gmail.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
srv_heupstream <srv_heupstream@mediatek.com>,
"Anders Berg" <anders.berg@avagotech.com>,
"Jim Cromie" <jim.cromie@gmail.com>,
"Simon Glass" <sjg@chromium.org>,
"Max Schwarz" <max.schwarz@online.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Sascha Hauer" <kernel@pengutronix.de>,
"Kumar Gala" <galak@codeaurora.org>
Subject: Re: [PATCH v5 2/3] I2C: mediatek: Add driver for MediaTek I2C controller
Date: Tue, 31 Mar 2015 19:52:34 +0200 [thread overview]
Message-ID: <20150331175234.GK9742@pengutronix.de> (raw)
In-Reply-To: <1427802658.32196.8.camel@mtksdaap41>
On Tue, Mar 31, 2015 at 07:50:58PM +0800, Eddie Huang wrote:
> Hi Sascha,
>
> On Tue, 2015-03-31 at 15:08 +0800, Eddie Huang wrote:
> > Hi Sascha,
> >
> > > > > speed <= 400000 here to make this more obvious?
> > > > There are two cases, not only speed<=400000, but I2C_MASTER_WRRD. I tend
> > > > to keep it.
> > >
> > > Still it looks strange. You only ever write this default value to the
> > > register. Putting this register write under an if() seems bogus since
> > > the same value will be in the register the next time this code is
> > > executed. It looks like you should move this register write to some
> > > initialization function.
> > OK, move to mtk_i2c_init_hw function
> >
> Sorry for my negligence. Write-then-read (I2C_MASTER_WRRD) decides
> according to each I2C transfer, so I still need to judge whether set
> I2C_CONTROL_RS and DELAY_LEN here. Other control setting can move to
> init function.
You need to decide whether you have to set the I2C_CONTROL_RS bit, but
you don't need to write the same value to the DELAY_LEN register each
time. It won't change under your hood.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
WARNING: multiple messages have this Message-ID (diff)
From: Sascha Hauer <s.hauer-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
To: Eddie Huang <eddie.huang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Cc: "Mark Rutland" <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
"Wolfram Sang" <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>,
"Doug Anderson"
<dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
"linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"David Box" <david.e.box-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
"Lee Jones" <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
"Jean Delvare" <jdelvare-l3A5Bk7waGM@public.gmane.org>,
"Xudong Chen (陈旭东)"
<Xudong.Chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>,
"Boris BREZILLON"
<boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>,
"Pawel Moll" <pawel.moll-5wv7dgnIgG8@public.gmane.org>,
"Liguo Zhang (张立国)"
<Liguo.Zhang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>,
"Wei Yan" <sledge.yanwei-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
"Bjorn Andersson"
<bjorn.andersson-/MT0OVThwyLZJqsBc5GL+g@public.gmane.org>,
"Uwe Kleine-Konig"
<u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
"Neelesh Gupta"
<neelegup-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"Arnd Bergmann" <arnd-r2nGTMty4D4@public.gmane.org>,
"Ian Campbell"
<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>,
"Beniamino Galvani"
<b.galvani-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH v5 2/3] I2C: mediatek: Add driver for MediaTek I2C controller
Date: Tue, 31 Mar 2015 19:52:34 +0200 [thread overview]
Message-ID: <20150331175234.GK9742@pengutronix.de> (raw)
In-Reply-To: <1427802658.32196.8.camel@mtksdaap41>
On Tue, Mar 31, 2015 at 07:50:58PM +0800, Eddie Huang wrote:
> Hi Sascha,
>
> On Tue, 2015-03-31 at 15:08 +0800, Eddie Huang wrote:
> > Hi Sascha,
> >
> > > > > speed <= 400000 here to make this more obvious?
> > > > There are two cases, not only speed<=400000, but I2C_MASTER_WRRD. I tend
> > > > to keep it.
> > >
> > > Still it looks strange. You only ever write this default value to the
> > > register. Putting this register write under an if() seems bogus since
> > > the same value will be in the register the next time this code is
> > > executed. It looks like you should move this register write to some
> > > initialization function.
> > OK, move to mtk_i2c_init_hw function
> >
> Sorry for my negligence. Write-then-read (I2C_MASTER_WRRD) decides
> according to each I2C transfer, so I still need to judge whether set
> I2C_CONTROL_RS and DELAY_LEN here. Other control setting can move to
> init function.
You need to decide whether you have to set the I2C_CONTROL_RS bit, but
you don't need to write the same value to the DELAY_LEN register each
time. It won't change under your hood.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
WARNING: multiple messages have this Message-ID (diff)
From: s.hauer@pengutronix.de (Sascha Hauer)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 2/3] I2C: mediatek: Add driver for MediaTek I2C controller
Date: Tue, 31 Mar 2015 19:52:34 +0200 [thread overview]
Message-ID: <20150331175234.GK9742@pengutronix.de> (raw)
In-Reply-To: <1427802658.32196.8.camel@mtksdaap41>
On Tue, Mar 31, 2015 at 07:50:58PM +0800, Eddie Huang wrote:
> Hi Sascha,
>
> On Tue, 2015-03-31 at 15:08 +0800, Eddie Huang wrote:
> > Hi Sascha,
> >
> > > > > speed <= 400000 here to make this more obvious?
> > > > There are two cases, not only speed<=400000, but I2C_MASTER_WRRD. I tend
> > > > to keep it.
> > >
> > > Still it looks strange. You only ever write this default value to the
> > > register. Putting this register write under an if() seems bogus since
> > > the same value will be in the register the next time this code is
> > > executed. It looks like you should move this register write to some
> > > initialization function.
> > OK, move to mtk_i2c_init_hw function
> >
> Sorry for my negligence. Write-then-read (I2C_MASTER_WRRD) decides
> according to each I2C transfer, so I still need to judge whether set
> I2C_CONTROL_RS and DELAY_LEN here. Other control setting can move to
> init function.
You need to decide whether you have to set the I2C_CONTROL_RS bit, but
you don't need to write the same value to the DELAY_LEN register each
time. It won't change under your hood.
Sascha
--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
next prev parent reply other threads:[~2015-03-31 17:53 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-21 6:05 [PATCH v5 0/3] ARM: mediatek: Add driver for Mediatek I2C controller Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-21 6:05 ` [PATCH v5 1/3] dt-bindings: Add I2C bindings for mt65xx/mt81xx Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-23 8:45 ` Sascha Hauer
2015-03-23 8:45 ` Sascha Hauer
2015-03-23 8:45 ` Sascha Hauer
2015-03-21 6:05 ` [PATCH v5 2/3] I2C: mediatek: Add driver for MediaTek I2C controller Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-23 8:42 ` Sascha Hauer
2015-03-23 8:42 ` Sascha Hauer
2015-03-23 8:42 ` Sascha Hauer
2015-03-30 8:14 ` Eddie Huang
2015-03-30 8:14 ` Eddie Huang
2015-03-30 8:14 ` Eddie Huang
2015-03-30 17:23 ` Sascha Hauer
2015-03-30 17:23 ` Sascha Hauer
2015-03-30 17:23 ` Sascha Hauer
2015-03-31 7:08 ` Eddie Huang
2015-03-31 7:08 ` Eddie Huang
2015-03-31 7:08 ` Eddie Huang
2015-03-31 11:50 ` Eddie Huang
2015-03-31 11:50 ` Eddie Huang
2015-03-31 11:50 ` Eddie Huang
2015-03-31 17:52 ` Sascha Hauer [this message]
2015-03-31 17:52 ` Sascha Hauer
2015-03-31 17:52 ` Sascha Hauer
2015-04-01 2:11 ` Eddie Huang
2015-04-01 2:11 ` Eddie Huang
2015-04-01 2:11 ` Eddie Huang
2015-03-21 6:05 ` [PATCH v5 3/3] I2C: mediatek: Add driver for MediaTek MT8173 " Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-21 6:05 ` Eddie Huang
2015-03-23 7:39 ` Sascha Hauer
2015-03-23 7:39 ` Sascha Hauer
2015-03-23 7:39 ` Sascha Hauer
2015-03-30 8:05 ` Eddie Huang
2015-03-30 8:05 ` Eddie Huang
2015-03-30 8:05 ` Eddie Huang
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=20150331175234.GK9742@pengutronix.de \
--to=s.hauer@pengutronix.de \
--cc=Liguo.Zhang@mediatek.com \
--cc=Xudong.Chen@mediatek.com \
--cc=anders.berg@avagotech.com \
--cc=arnd@arndb.de \
--cc=b.galvani@gmail.com \
--cc=bjorn.andersson@sonymobile.com \
--cc=boris.brezillon@free-electrons.com \
--cc=david.e.box@linux.intel.com \
--cc=devicetree@vger.kernel.org \
--cc=dianders@chromium.org \
--cc=eddie.huang@mediatek.com \
--cc=galak@codeaurora.org \
--cc=ijc+devicetree@hellion.org.uk \
--cc=jdelvare@suse.de \
--cc=jim.cromie@gmail.com \
--cc=kernel@pengutronix.de \
--cc=lee.jones@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-i2c@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=matthias.bgg@gmail.com \
--cc=max.schwarz@online.de \
--cc=neelegup@linux.vnet.ibm.com \
--cc=pawel.moll@arm.com \
--cc=robh+dt@kernel.org \
--cc=sjg@chromium.org \
--cc=sledge.yanwei@huawei.com \
--cc=srv_heupstream@mediatek.com \
--cc=u.kleine-koenig@pengutronix.de \
--cc=wsa@the-dreams.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.