Re: [DO NOT MERGE v6 12/37] dt-bindings: pci: pci-sh7751: Add SH7751 PCI

On Tue, Jan 09, 2024 at 01:42:53PM +0100, Linus Walleij wrote:

Hi Yoshinori,

thanks for your patch!

On Tue, Jan 9, 2024 at 9:24 AM Yoshinori Sato
[off-list ref] wrote:

quoted

Renesas SH7751 PCI Controller json-schema.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>

(...)

quoted

+  renesas,bus-arbit-round-robin:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set DMA bus arbitration to round robin.
+
+  pci-command-reg-fast-back-to-back:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI command register Fast Back-to-Back enable bit.
+
+  pci-command-reg-serr:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI command register SERR# enable.
+
+  pci-command-reg-wait-cycle-control:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI command register Wait cycle control bit.
+
+  pci-command-reg-parity-error-response:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register Parity error response bit.
+
+  pci-command-reg-vga-snoop:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register VGA palette snoop bit.
+
+  pci-command-reg-write-invalidate:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register Memory write and invaldate enable bit.
+
+  pci-command-reg-special-cycle:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register Special cycle bit.
+
+  pci-command-reg-bus-master:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register Bus master bit.
+
+  pci-command-reg-memory-space:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register Memory space bit.
+
+  pci-command-reg-io-space:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description: |
+      Set for PCI Command register I/O space bit.

Do you really need to configure all these things? It seems they are
just set to default values anyway?

Can't you just look at the compatible "renesas,sh7751-pci" and
set it to the values you know are needed for that compatible?

Yes. Please drop all these.

quoted

+  pci-bar:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    description: Overwrite to  PCI CONFIG Base Address Registers value.
+    items:
+      items:
+        - description: BAR register number
+        - description: BAR register value
+    minItems: 1
+    maxItems: 6

Same with this, isn't this always the same (hardcoded) values
for "renesas,sh7751-pci" if used?

The OpenFirmware PCI bus supplement already defines how to specify BAR 
values in DT in "reg" or "assigned-addresses". If you need to specify 
these, use that. Note don't expect the kernel to do anything with them.

Rob

quoted

+            interrupt-map = <0x0000 0 0 1 &julianintc 5>,
+                            <0x0000 0 0 2 &julianintc 6>,
+                            <0x0000 0 0 3 &julianintc 7>,
+                            <0x0000 0 0 4 &julianintc 8>,
+                            <0x0800 0 0 1 &julianintc 6>,
+                            <0x0800 0 0 2 &julianintc 7>,
+                            <0x0800 0 0 3 &julianintc 8>,
+                            <0x0800 0 0 4 &julianintc 5>,
+                            <0x1000 0 0 1 &julianintc 7>,
+                            <0x1000 0 0 2 &julianintc 8>,
+                            <0x1000 0 0 3 &julianintc 5>,
+                            <0x1000 0 0 4 &julianintc 6>;

This interrupt-map looks very strange, usually the last cell is the polarity
flag and here it is omitted? I would expect something like:

<0x0000 0 0 1 &julianintc 5 IRQ_TYPE_LEVEL_LOW>, (...)

The interrupt-map schema in dtschema isn't really looking at this
so it is easy to get it wrong.

dtc should IIRC. Maybe not in the example being incomplete.

Rob