Messages in this thread | | | Date | Wed, 3 May 2023 10:02:13 +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 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?
Thanks, Michal
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