ARM: dts: vf610-zii-cfu1: Slow I2C0 down to 100kHz
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Message ID 20190820030804.8892-1-andrew.smirnov@gmail.com
State Accepted
Commit 801592402c392acb0f2ead971d1e8f0e0565b60e
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Series
  • ARM: dts: vf610-zii-cfu1: Slow I2C0 down to 100kHz
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Commit Message

Andrey Smirnov Aug. 20, 2019, 3:08 a.m. UTC
Fiber-optic module attached to the bus is only rated to work at
100kHz, so drop the bus frequncy to accomodate that.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 arch/arm/boot/dts/vf610-zii-cfu1.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Chris Healy Aug. 20, 2019, 2:08 p.m. UTC | #1
On Mon, Aug 19, 2019 at 8:08 PM Andrey Smirnov <andrew.smirnov@gmail.com> wrote:
>
> Fiber-optic module attached to the bus is only rated to work at
> 100kHz, so drop the bus frequncy to accomodate that.
>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> Cc: Shawn Guo <shawnguo@kernel.org>
> Cc: Chris Healy <cphealy@gmail.com>
> Cc: Fabio Estevam <festevam@gmail.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  arch/arm/boot/dts/vf610-zii-cfu1.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/vf610-zii-cfu1.dts b/arch/arm/boot/dts/vf610-zii-cfu1.dts
> index ff460a1de85a..28732249cfc0 100644
> --- a/arch/arm/boot/dts/vf610-zii-cfu1.dts
> +++ b/arch/arm/boot/dts/vf610-zii-cfu1.dts
> @@ -207,7 +207,7 @@
>  };
>
>  &i2c0 {
> -       clock-frequency = <400000>;
> +       clock-frequency = <100000>;
>         pinctrl-names = "default";
>         pinctrl-0 = <&pinctrl_i2c0>;
>         status = "okay";
> --
> 2.21.0
>

Reviewed-by: Chris Healy <cphealy@gmail.com>
Marc Gonzalez Aug. 20, 2019, 2:39 p.m. UTC | #2
On 20/08/2019 05:08, Andrey Smirnov wrote:

> Fiber-optic module attached to the bus is only rated to work at
> 100kHz, so drop the bus frequncy to accomodate that.

s/100kHz/100 kHz
s/frequncy/frequency
s/accomodate/accommodate

Regards.
Andrew Lunn Aug. 20, 2019, 3:29 p.m. UTC | #3
On Mon, Aug 19, 2019 at 08:08:04PM -0700, Andrey Smirnov wrote:
> Fiber-optic module attached to the bus is only rated to work at
> 100kHz, so drop the bus frequncy to accomodate that.

Hi Andrey

Did you review all the other ZII platforms? I could imaging the same
problem happening else where.

Thanks
	Andrew
Andrey Smirnov Aug. 21, 2019, 1:30 a.m. UTC | #4
On Tue, Aug 20, 2019 at 7:41 AM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
>
> On 20/08/2019 05:08, Andrey Smirnov wrote:
>
> > Fiber-optic module attached to the bus is only rated to work at
> > 100kHz, so drop the bus frequncy to accomodate that.
>
> s/100kHz/100 kHz
> s/frequncy/frequency
> s/accomodate/accommodate
>

Will fix in v2.

Thanks,
Andrey Smirnov
Andrey Smirnov Aug. 21, 2019, 1:35 a.m. UTC | #5
On Tue, Aug 20, 2019 at 8:29 AM Andrew Lunn <andrew@lunn.ch> wrote:
>
> On Mon, Aug 19, 2019 at 08:08:04PM -0700, Andrey Smirnov wrote:
> > Fiber-optic module attached to the bus is only rated to work at
> > 100kHz, so drop the bus frequncy to accomodate that.
>
> Hi Andrey
>
> Did you review all the other ZII platforms? I could imaging the same
> problem happening else where.
>

Yes, AFAICT, fiber-optic modules are present only on SCU4
(vf610-zii-scu4-aib.dts), CFU1 (vf610-zii-cfu1.dts) and VF610 Dev
board rev. B/C (vf610-zii-dev*.dts[i]). Of all three only CFU1 has
corresponding I2C bus running @ 400 kHz.

Thanks,
Andrey Smirnov

Patch
diff mbox series

diff --git a/arch/arm/boot/dts/vf610-zii-cfu1.dts b/arch/arm/boot/dts/vf610-zii-cfu1.dts
index ff460a1de85a..28732249cfc0 100644
--- a/arch/arm/boot/dts/vf610-zii-cfu1.dts
+++ b/arch/arm/boot/dts/vf610-zii-cfu1.dts
@@ -207,7 +207,7 @@ 
 };
 
 &i2c0 {
-	clock-frequency = <400000>;
+	clock-frequency = <100000>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_i2c0>;
 	status = "okay";