[PATCH 0/2] Add support for AMD Versal2 CPM6 host bridge

[PATCH 0/2] Add support for AMD Versal2 CPM6 host bridge

[Sai Krishna Musham]

Add the "amd,versal2-cpm6-host" compatible string to the AMD MDB PCIe
host controller driver and its devicetree binding.

Sai Krishna Musham (2):
  dt-bindings: PCI: Add compatible for AMD Versal2 CPM6 host bridge
  PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

 .../devicetree/bindings/pci/amd,versal2-mdb-host.yaml         | 4 +++-
 drivers/pci/controller/dwc/pcie-amd-mdb.c                     | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

-- 
2.44.4

[PATCH 1/2] dt-bindings: PCI: Add compatible for AMD Versal2 CPM6 host bridge

[Sai Krishna Musham]

Add the "amd,versal2-cpm6-host" compatible string for AMD Versal2 CPM6
host bridge.

CPM6 integrates a Synopsys DesignWare PCIe Root Port controller derived
from the same IP family as the existing MDB host bridge, but uses a
newer IP revision, supports PCIe Gen6 operation up to 64 GT/s per lane
and has differences in register layout.

A separate compatible string is required to accurately describe the
CPM6 hardware and allow software to distinguish it from the MDB-based
host bridge.

Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
---
 .../devicetree/bindings/pci/amd,versal2-mdb-host.yaml         | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
index 406c15e1dee1..be5a77908d24 100644
--- a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
+++ b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
@@ -15,7 +15,9 @@ allOf:
 
 properties:
   compatible:
-    const: amd,versal2-mdb-host
+    enum:
+      - amd,versal2-mdb-host
+      - amd,versal2-cpm6-host
 
   reg:
     items:
-- 
2.44.4

Re: [PATCH 1/2] dt-bindings: PCI: Add compatible for AMD Versal2 CPM6 host bridge

[Krzysztof Kozlowski]

On 02/04/2026 20:00, Sai Krishna Musham wrote:
> Add the "amd,versal2-cpm6-host" compatible string for AMD Versal2 CPM6
> host bridge.
> 
> CPM6 integrates a Synopsys DesignWare PCIe Root Port controller derived
> from the same IP family as the existing MDB host bridge, but uses a
> newer IP revision, supports PCIe Gen6 operation up to 64 GT/s per lane
> and has differences in register layout.
> 
> A separate compatible string is required to accurately describe the
> CPM6 hardware and allow software to distinguish it from the MDB-based
> host bridge.
> 
> Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
> ---
>  .../devicetree/bindings/pci/amd,versal2-mdb-host.yaml         | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
> index 406c15e1dee1..be5a77908d24 100644
> --- a/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
> +++ b/Documentation/devicetree/bindings/pci/amd,versal2-mdb-host.yaml
> @@ -15,7 +15,9 @@ allOf:
>  
>  properties:
>    compatible:
> -    const: amd,versal2-mdb-host
> +    enum:
> +      - amd,versal2-mdb-host
> +      - amd,versal2-cpm6-host

Why reversed alphabetical order?

Best regards,
Krzysztof

[PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

[Sai Krishna Musham]

Add "amd,versal2-cpm6-host" to the OF match table of the AMD MDB PCIe
host controller driver.

The Versal2 CPM6 host controller is DesignWare-based and supports
PCIe Gen6 operation at up to 64 GT/s per lane. It is currently
handled by the same driver and match data (NULL) as the existing
MDB host controller, but CPM6 uses a newer IP revision and differs
in legacy INTx register offsets.

Use a separate compatible to allow CPM6-specific handling once legacy
interrupt support is validated.

Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
---
 drivers/pci/controller/dwc/pcie-amd-mdb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c
index 3c6e837465bb..325bf7aad657 100644
--- a/drivers/pci/controller/dwc/pcie-amd-mdb.c
+++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
@@ -511,6 +511,9 @@ static const struct of_device_id amd_mdb_pcie_of_match[] = {
 	{
 		.compatible = "amd,versal2-mdb-host",
 	},
+	{
+		.compatible = "amd,versal2-cpm6-host",
+	},
 	{},
 };
 
-- 
2.44.4

Re: [PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

[Krzysztof Kozlowski]

On 02/04/2026 20:00, Sai Krishna Musham wrote:
> Add "amd,versal2-cpm6-host" to the OF match table of the AMD MDB PCIe
> host controller driver.
> 
> The Versal2 CPM6 host controller is DesignWare-based and supports
> PCIe Gen6 operation at up to 64 GT/s per lane. It is currently
> handled by the same driver and match data (NULL) as the existing
> MDB host controller, but CPM6 uses a newer IP revision and differs
> in legacy INTx register offsets.
> 
> Use a separate compatible to allow CPM6-specific handling once legacy
> interrupt support is validated.
> 
> Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
> ---
>  drivers/pci/controller/dwc/pcie-amd-mdb.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> index 3c6e837465bb..325bf7aad657 100644
> --- a/drivers/pci/controller/dwc/pcie-amd-mdb.c
> +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> @@ -511,6 +511,9 @@ static const struct of_device_id amd_mdb_pcie_of_match[] = {
>  	{
>  		.compatible = "amd,versal2-mdb-host",
>  	},
> +	{
> +		.compatible = "amd,versal2-cpm6-host",
> +	},

So devices are fully compatible. Fix your compatibility in the binding
and drop this.

Best regards,
Krzysztof

Re: [PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

[Manivannan Sadhasivam]

On Thu, Apr 02, 2026 at 11:30:06PM +0530, Sai Krishna Musham wrote:
> Add "amd,versal2-cpm6-host" to the OF match table of the AMD MDB PCIe
> host controller driver.
> 
> The Versal2 CPM6 host controller is DesignWare-based and supports
> PCIe Gen6 operation at up to 64 GT/s per lane. It is currently
> handled by the same driver and match data (NULL) as the existing
> MDB host controller, but CPM6 uses a newer IP revision and differs
> in legacy INTx register offsets.
> 
> Use a separate compatible to allow CPM6-specific handling once legacy
> interrupt support is validated.
> 
> Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
> ---
>  drivers/pci/controller/dwc/pcie-amd-mdb.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> index 3c6e837465bb..325bf7aad657 100644
> --- a/drivers/pci/controller/dwc/pcie-amd-mdb.c
> +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> @@ -511,6 +511,9 @@ static const struct of_device_id amd_mdb_pcie_of_match[] = {
>  	{
>  		.compatible = "amd,versal2-mdb-host",
>  	},
> +	{
> +		.compatible = "amd,versal2-cpm6-host",

As Krzysztof commented, if the PCIe IP is compatible with an older version,
'amd,versal2-mdb-host' in this case, you don't need to add the new compatible
to the driver. Just document the new one with fallback to the old compatible in
the binding and let the driver work with the old compatible.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

RE: [PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host compatible

[Musham, Sai Krishna]

[Public]

Hi Krzysztof/Manivannan,

> -----Original Message-----
> From: Manivannan Sadhasivam <mani@kernel.org>
> Sent: Saturday, April 4, 2026 8:46 AM
> To: Musham, Sai Krishna <sai.krishna.musham@amd.com>
> Cc: bhelgaas@google.com; lpieralisi@kernel.org; kw@linux.com;
> robh@kernel.org; krzk+dt@kernel.org; conor+dt@kernel.org;
> cassel@kernel.org; linux-pci@vger.kernel.org; devicetree@vger.kernel.org;
> linux-kernel@vger.kernel.org; Simek, Michal <michal.simek@amd.com>;
> Gogada, Bharat Kumar <bharat.kumar.gogada@amd.com>; Havalige,
> Thippeswamy <thippeswamy.havalige@amd.com>
> Subject: Re: [PATCH 2/2] PCI: amd-mdb: Add amd,versal2-cpm6-host
> compatible
>
> On Thu, Apr 02, 2026 at 11:30:06PM +0530, Sai Krishna Musham wrote:
> > Add "amd,versal2-cpm6-host" to the OF match table of the AMD MDB PCIe
> > host controller driver.
> >
> > The Versal2 CPM6 host controller is DesignWare-based and supports
> > PCIe Gen6 operation at up to 64 GT/s per lane. It is currently
> > handled by the same driver and match data (NULL) as the existing
> > MDB host controller, but CPM6 uses a newer IP revision and differs
> > in legacy INTx register offsets.
> >
> > Use a separate compatible to allow CPM6-specific handling once legacy
> > interrupt support is validated.
> >
> > Signed-off-by: Sai Krishna Musham <sai.krishna.musham@amd.com>
> > ---
> >  drivers/pci/controller/dwc/pcie-amd-mdb.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-amd-mdb.c
> b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> > index 3c6e837465bb..325bf7aad657 100644
> > --- a/drivers/pci/controller/dwc/pcie-amd-mdb.c
> > +++ b/drivers/pci/controller/dwc/pcie-amd-mdb.c
> > @@ -511,6 +511,9 @@ static const struct of_device_id
> amd_mdb_pcie_of_match[] = {
> >     {
> >             .compatible = "amd,versal2-mdb-host",
> >     },
> > +   {
> > +           .compatible = "amd,versal2-cpm6-host",
>
> As Krzysztof commented, if the PCIe IP is compatible with an older version,
> 'amd,versal2-mdb-host' in this case, you don't need to add the new
> compatible
> to the driver. Just document the new one with fallback to the old compatible
> in
> the binding and let the driver work with the old compatible.
>

Thanks for the review. CPM6 uses a different DesignWare IP revision and
has differences in legacy interrupt register offsets. I will send a follow-up
patch to address these.

> - Mani
>
> --
> மணிவண்ணன் சதாசிவம்


Regards,
Sai Krishna