RE: [PATCH v3 3/8] arm64: dts: ls1028a: add flextimer based pwm nodes

From: Leo Li
Date: Wed Apr 13 2022 - 15:12:21 EST




> -----Original Message-----
> From: Vladimir Oltean <olteanv@xxxxxxxxx>
> Sent: Wednesday, April 13, 2022 1:23 PM
> To: Leo Li <leoyang.li@xxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Biwen Li
> <biwen.li@xxxxxxx>
> Subject: Re: [PATCH v3 3/8] arm64: dts: ls1028a: add flextimer based pwm
> nodes
>
> On Wed, Apr 13, 2022 at 06:07:20PM +0000, Leo Li wrote:
> > > arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi:1210.21-1219.5:
> > > Warning
> > > (unique_unit_address): /soc/pwm@2800000: duplicate unit-address
> > > (also used in node /soc/timer@2800000)
> > > arch/arm64/boot/dts/freescale/fsl-ls1028a.dtsi:1221.21-1230.5:
> > > Warning
> > > (unique_unit_address): /soc/pwm@2810000: duplicate unit-address
> > > (also used in node /soc/timer@2810000)
> >
> > Well, this is similar situation as pcie. The flextimer controller can
> > be used as timer, PWM or alarm. We have separate drivers and bindings
> > for these modes which resulted in different nodes for the same
> > controller.
>
> I think the mfd framework can address the situation where multiple drivers,
> with multiple functionalities, want access to the same memory region?

I know mfd is used for device providing multiple functions at the same time. I'm not sure if it can help dealing with the one function at a time scenario.

Regards,
Leo