Re: [PATCH v2 1/5] arm64: dts: qcom: sm8550: add PCIe MHI register regions

[Joe Sandom <jsandom@axon.com>]

On Tue, Apr 07, 2026 at 07:38:54PM +0200, Neil Armstrong wrote:
> On 4/7/26 17:46, Joe Sandom wrote:
> > Add the MHI register regions to the pcie0 and pcie1 controller nodes
> > so that the MHI bus layer can access controller registers directly.
> 
> Can you elaborate more on that ? Looking at the current implementation,
> the pcie host driver only uses the mhi memory zone to show the transition
> count in debugfs.
>
hmm yeah, you're right. As you said, it's only used for transition count
currently. I'll make sure the commit message is clearer in v3.
> Neil
> 
> > 
> > Signed-off-by: Joe Sandom <jsandom@axon.com>
> > ---
> >   arch/arm64/boot/dts/qcom/sm8550.dtsi | 20 ++++++++++++++++----
> >   1 file changed, 16 insertions(+), 4 deletions(-)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/sm8550.dtsi b/arch/arm64/boot/dts/qcom/sm8550.dtsi
> > index 912525e9bca6f5e1cbb8887ee0bf9e39650dc4ff..055ca931c04859f3a312eb9921aeb7a8cc676822 100644
> > --- a/arch/arm64/boot/dts/qcom/sm8550.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sm8550.dtsi
> > @@ -1964,8 +1964,14 @@ pcie0: pcie@1c00000 {
> >   			      <0 0x60000000 0 0xf1d>,
> >   			      <0 0x60000f20 0 0xa8>,
> >   			      <0 0x60001000 0 0x1000>,
> > -			      <0 0x60100000 0 0x100000>;
> > -			reg-names = "parf", "dbi", "elbi", "atu", "config";
> > +			      <0 0x60100000 0 0x100000>,
> > +			      <0 0x01c03000 0 0x1000>;
> > +			reg-names = "parf",
> > +				    "dbi",
> > +				    "elbi",
> > +				    "atu",
> > +				    "config",
> > +				    "mhi";
> >   			#address-cells = <3>;
> >   			#size-cells = <2>;
> >   			ranges = <0x01000000 0x0 0x00000000 0x0 0x60200000 0x0 0x100000>,
> > @@ -2138,8 +2144,14 @@ pcie1: pcie@1c08000 {
> >   			      <0x0 0x40000000 0x0 0xf1d>,
> >   			      <0x0 0x40000f20 0x0 0xa8>,
> >   			      <0x0 0x40001000 0x0 0x1000>,
> > -			      <0x0 0x40100000 0x0 0x100000>;
> > -			reg-names = "parf", "dbi", "elbi", "atu", "config";
> > +			      <0x0 0x40100000 0x0 0x100000>,
> > +			      <0x0 0x01c0b000 0x0 0x1000>;
> > +			reg-names = "parf",
> > +				    "dbi",
> > +				    "elbi",
> > +				    "atu",
> > +				    "config",
> > +				    "mhi";
> >   			#address-cells = <3>;
> >   			#size-cells = <2>;
> >   			ranges = <0x01000000 0x0 0x00000000 0x0 0x40200000 0x0 0x100000>,
> > 
>