Messages in this thread | | | Date | Wed, 3 May 2023 10:09:02 +0200 | Subject | Re: [PATCH] ARM: zynq: dts: Setting default i2c clock frequency to 400kHz | From | Michal Simek <> |
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On 5/3/23 10:06, Krzysztof Kozlowski wrote: > On 03/05/2023 10:02, Michal Simek wrote: >> >> >> On 5/3/23 09:40, Krzysztof Kozlowski wrote: >>> On 03/05/2023 09:27, Michal Simek wrote: >>>> >>>> >>>> On 5/2/23 22:13, Krzysztof Kozlowski wrote: >>>>> CAUTION: This message has originated from an External Source. Please use proper judgment and caution when opening attachments, clicking links, or responding to this email. >>>>> >>>>> >>>>> On 02/05/2023 15:53, Michal Simek wrote: >>>>>> From: Varalaxmi Bingi <varalaxmi.bingi@amd.com> >>>>>> >>>>>> Setting default i2c clock frequency for Zynq to maximum rate of 400kHz. >>>>>> Current default value is 100kHz. >>>>>> >>>>>> Signed-off-by: Varalaxmi Bingi <varalaxmi.bingi@amd.com> >>>>>> Signed-off-by: Michal Simek <michal.simek@amd.com> >>>>>> --- >>>>>> >>>>>> arch/arm/boot/dts/zynq-7000.dtsi | 2 ++ >>>>>> 1 file changed, 2 insertions(+) >>>>>> >>>>>> diff --git a/arch/arm/boot/dts/zynq-7000.dtsi b/arch/arm/boot/dts/zynq-7000.dtsi >>>>>> index cd9931f6bcbd..a7db3f3009f2 100644 >>>>>> --- a/arch/arm/boot/dts/zynq-7000.dtsi >>>>>> +++ b/arch/arm/boot/dts/zynq-7000.dtsi >>>>>> @@ -149,6 +149,7 @@ i2c0: i2c@e0004000 { >>>>>> clocks = <&clkc 38>; >>>>>> interrupt-parent = <&intc>; >>>>>> interrupts = <0 25 4>; >>>>>> + clock-frequency = <400000>; >>>>> >>>>> I think this should be rather property of the board, because it depends >>>>> on I2C devices, right? >>>> >>>> We have 15+ boards with i2c connected and from this count I am aware about only >>>> one configuration which is not working on 400k. >>>> It is a question if make sense to update all boards (except for 1 and not all in >>>> kernel yet) to 400k or just say 400k is default and if there is any issue use >>>> lower frequency. >>>> Obviously this patch is setting up 400k as default and let "problematic" boards >>>> to setup lower freq. >>>> The same approach was used for modepin description. >>>> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/arm64/boot/dts/xilinx/zynqmp.dtsi?h=v6.3&id=53ba1b2bdaf7f481fdd878e9c18cd0e54081fac9 >>>> >>>> The next point is that 100k is default in Linux but doesn't mean it is default >>>> in other projects. >>>> >>>> But if you think that it must be board property I think we should setup 100k as >>>> default in this file too to make it clear. >>> >>> No, if it is conscious choice, it's fine. >> >> Is it Ack then or you want me to extend commit message? > > Ack, although you don't need my acks for your platform :)
you spell that properly. But I can. :-)
> > FWIW: > > Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Thanks, Michal
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