From: Wolfram Sang <wsa@the-dreams.de>
To: Addy Ke <addy.ke@rock-chips.com>
Cc: max.schwarz@online.de, heiko@sntech.de, olof@lixom.net,
dianders@chromium.org, robh+dt@kernel.org, pawel.moll@arm.com,
ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
u.kleine-koenig@pengutronix.de, linux-i2c@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-rockchip@lists.infradead.org, cf@rock-chips.com,
xjq@rock-chips.com, huangtao@rock-chips.com, zyw@rock-chips.com,
yzq@rock-chips.com, hj@rock-chips.com, kever.yang@rock-chips.com,
hl@rock-chips.com, caesar.wang@rock-chips.com,
zhengsq@rock-chips.com
Subject: Re: [PATCH v5] i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C specification
Date: Tue, 13 Jan 2015 12:42:37 +0100 [thread overview]
Message-ID: <20150113114237.GC7660@katana> (raw)
In-Reply-To: <1418295760-19639-1-git-send-email-addy.ke@rock-chips.com>
[-- Attachment #1: Type: text/plain, Size: 1255 bytes --]
On Thu, Dec 11, 2014 at 07:02:40PM +0800, Addy Ke wrote:
> The number of clock cycles to be written into the CLKDIV register
> that determines the I2C clk high phase includes the rise time.
> So to meet the timing requirements defined in the I2C specification
> which defines the minimal time SCL has to be high, the rise time
> has to taken into account. The same applies to the low phase with
> falling time.
>
> In my test on RK3288-Pink2 board, which is not an upstream board yet,
> if external pull-up resistor is 4.7K, rise_ns is about 700ns.
> So the measured high_ns is about 3900ns, which is less than 4000ns
> (the minimum high_ns in I2C specification for Standard-mode).
>
> To fix this bug min_low_ns should include fall time and min_high_ns
> should include rise time.
>
> This patch merged the patch from chromium project which can get the
> rise and fall times for signals from the device tree. This allows us
> to more accurately calculate timings. see:
> https://chromium-review.googlesource.com/#/c/232774/
>
> Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Applied to for-next, thanks!
I fixed the typo Doug mentioned.
Please send new patches as seperate threads, not as a reply to the old
patch.
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WARNING: multiple messages have this Message-ID (diff)
From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
To: Addy Ke <addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Cc: max.schwarz-BGeptl67XyCzQB+pC5nmwQ@public.gmane.org,
heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org,
olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org,
dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
pawel.moll-5wv7dgnIgG8@public.gmane.org,
ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org,
galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org,
u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
zyw-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
yzq-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
kever.yang-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
hl-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
caesar.wang-TNX95d0MmH7DzftRWevZcw@public.gmane.org,
zhengsq-TNX95d0MmH7DzftRWevZcw@public.gmane.org
Subject: Re: [PATCH v5] i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C specification
Date: Tue, 13 Jan 2015 12:42:37 +0100 [thread overview]
Message-ID: <20150113114237.GC7660@katana> (raw)
In-Reply-To: <1418295760-19639-1-git-send-email-addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
[-- Attachment #1: Type: text/plain, Size: 1280 bytes --]
On Thu, Dec 11, 2014 at 07:02:40PM +0800, Addy Ke wrote:
> The number of clock cycles to be written into the CLKDIV register
> that determines the I2C clk high phase includes the rise time.
> So to meet the timing requirements defined in the I2C specification
> which defines the minimal time SCL has to be high, the rise time
> has to taken into account. The same applies to the low phase with
> falling time.
>
> In my test on RK3288-Pink2 board, which is not an upstream board yet,
> if external pull-up resistor is 4.7K, rise_ns is about 700ns.
> So the measured high_ns is about 3900ns, which is less than 4000ns
> (the minimum high_ns in I2C specification for Standard-mode).
>
> To fix this bug min_low_ns should include fall time and min_high_ns
> should include rise time.
>
> This patch merged the patch from chromium project which can get the
> rise and fall times for signals from the device tree. This allows us
> to more accurately calculate timings. see:
> https://chromium-review.googlesource.com/#/c/232774/
>
> Signed-off-by: Addy Ke <addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Applied to for-next, thanks!
I fixed the typo Doug mentioned.
Please send new patches as seperate threads, not as a reply to the old
patch.
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WARNING: multiple messages have this Message-ID (diff)
From: wsa@the-dreams.de (Wolfram Sang)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5] i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C specification
Date: Tue, 13 Jan 2015 12:42:37 +0100 [thread overview]
Message-ID: <20150113114237.GC7660@katana> (raw)
In-Reply-To: <1418295760-19639-1-git-send-email-addy.ke@rock-chips.com>
On Thu, Dec 11, 2014 at 07:02:40PM +0800, Addy Ke wrote:
> The number of clock cycles to be written into the CLKDIV register
> that determines the I2C clk high phase includes the rise time.
> So to meet the timing requirements defined in the I2C specification
> which defines the minimal time SCL has to be high, the rise time
> has to taken into account. The same applies to the low phase with
> falling time.
>
> In my test on RK3288-Pink2 board, which is not an upstream board yet,
> if external pull-up resistor is 4.7K, rise_ns is about 700ns.
> So the measured high_ns is about 3900ns, which is less than 4000ns
> (the minimum high_ns in I2C specification for Standard-mode).
>
> To fix this bug min_low_ns should include fall time and min_high_ns
> should include rise time.
>
> This patch merged the patch from chromium project which can get the
> rise and fall times for signals from the device tree. This allows us
> to more accurately calculate timings. see:
> https://chromium-review.googlesource.com/#/c/232774/
>
> Signed-off-by: Addy Ke <addy.ke@rock-chips.com>
Applied to for-next, thanks!
I fixed the typo Doug mentioned.
Please send new patches as seperate threads, not as a reply to the old
patch.
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next prev parent reply other threads:[~2015-01-13 11:42 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-06 8:11 [PATCH] i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C spec Addy Ke
2014-11-06 8:11 ` Addy Ke
2014-11-06 8:11 ` Addy Ke
2014-12-02 23:02 ` Doug Anderson
2014-12-02 23:02 ` Doug Anderson
2014-12-03 2:37 ` [PATCH v2] " Addy Ke
2014-12-03 2:37 ` Addy Ke
2014-12-03 2:37 ` Addy Ke
2014-12-03 5:13 ` Doug Anderson
2014-12-03 5:13 ` Doug Anderson
2014-12-03 5:13 ` Doug Anderson
2014-12-03 11:15 ` Wolfram Sang
2014-12-03 11:15 ` Wolfram Sang
2014-12-03 11:15 ` Wolfram Sang
2014-12-03 17:53 ` Doug Anderson
2014-12-03 17:53 ` Doug Anderson
2014-12-03 17:53 ` Doug Anderson
2014-12-04 18:40 ` Wolfram Sang
2014-12-04 18:40 ` Wolfram Sang
2014-12-04 18:40 ` Wolfram Sang
2014-12-04 18:43 ` Doug Anderson
2014-12-04 18:43 ` Doug Anderson
2014-12-04 18:43 ` Doug Anderson
2014-12-04 19:03 ` Wolfram Sang
2014-12-04 19:03 ` Wolfram Sang
2014-12-04 19:03 ` Wolfram Sang
2014-12-05 19:31 ` Doug Anderson
2014-12-05 19:31 ` Doug Anderson
2014-12-05 19:31 ` Doug Anderson
2014-12-08 2:59 ` [PATCH v3] " Addy Ke
2014-12-08 2:59 ` Addy Ke
2014-12-08 2:59 ` Addy Ke
2014-12-08 3:06 ` addy ke
2014-12-08 3:06 ` addy ke
2014-12-08 3:06 ` addy ke
2014-12-08 8:52 ` Uwe Kleine-König
2014-12-08 8:52 ` Uwe Kleine-König
2014-12-08 17:13 ` Doug Anderson
2014-12-08 17:13 ` Doug Anderson
2014-12-08 17:13 ` Doug Anderson
2014-12-08 17:34 ` Wolfram Sang
2014-12-08 17:34 ` Wolfram Sang
2014-12-08 17:34 ` Wolfram Sang
2014-12-08 18:53 ` Doug Anderson
2014-12-08 18:53 ` Doug Anderson
2014-12-08 18:53 ` Doug Anderson
2014-12-08 20:04 ` Uwe Kleine-König
2014-12-08 20:04 ` Uwe Kleine-König
2014-12-08 20:04 ` Uwe Kleine-König
2014-12-11 6:00 ` [PATCH v4] i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C specification Addy Ke
2014-12-11 6:00 ` Addy Ke
2014-12-11 6:00 ` Addy Ke
2014-12-11 7:47 ` Uwe Kleine-König
2014-12-11 7:47 ` Uwe Kleine-König
2014-12-11 7:47 ` Uwe Kleine-König
2014-12-11 11:02 ` [PATCH v5] " Addy Ke
2014-12-11 11:02 ` Addy Ke
2014-12-11 19:22 ` Doug Anderson
2014-12-11 19:22 ` Doug Anderson
2014-12-11 19:22 ` Doug Anderson
2015-01-13 11:42 ` Wolfram Sang [this message]
2015-01-13 11:42 ` Wolfram Sang
2015-01-13 11:42 ` Wolfram Sang
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