Re: [PATCH] ARM: dts: alt: Add DA9063 PMIC node

[Wolfram Sang <wsa@the-dreams.de>]

[-- Attachment #1.1: Type: text/plain, Size: 1516 bytes --]

On Mon, Mar 04, 2019 at 11:59:48AM +0100, Marek Vasut wrote:
> On 3/4/19 11:57 AM, Wolfram Sang wrote:
> > 
> >>> Add DA9063 PMIC node to the I2C bus.
> >>>
> >>> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> >>
> >> Thanks for your patch!
> >>
> >> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > 
> > Thanks for CCing me, I didn't get and missed the original patch.
> > 
> >>> +++ b/arch/arm/boot/dts/r8a7794-alt.dts
> >>> @@ -377,6 +377,27 @@
> >>>         pinctrl-names = "i2c-exio4";
> >>>  };
> >>>
> >>> +&i2c7 {
> >>> +       status = "okay";
> >>> +       clock-frequency = <100000>;
> >>
> >> According to the DA9063 datasheet, the PMIC supports up to 400 kHz.
> >> It looks like there are no other devices on the bus.
> >>
> >> Wolfram, what's your stance on this?
> > 
> > Yes, please. I thought this was standard on Gen2 IIC_DVFS busses, but
> > seems not. Probably it slipped through the cracks.
> 
> Do we want to update all of the other boards too ?
> 
> I'd be cautious about the DVFS I2C, running faster while talking to the
> PMIC and reading/writing a few registers brings little benefit, while
> the signal integrity might be impacted.

Can be argued. I think if we would apply some testing on top of this
change, we will find that it will work. But we would in deed need this
testing as verification, and this is not our top priority project. But
if someone feels like running some i2c dumping over night, well,
why not..


[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

[-- Attachment #2: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel