On Sat, Sep 19, 2020 at 2:23 PM Christian Lamparter [off-list ref] wrote:

On 2020-09-15 03:05, Rob Herring wrote:

quoted

On Sun, Sep 06, 2020 at 12:06:12AM +0200, Christian Lamparter wrote:

quoted

This patch adds an DTSI-File that can be used by various device-tree
files for APM82181-based devices.

Some of the nodes (like UART, PCIE, SATA) are used by the uboot and
need to stick with the naming-conventions of the old times'.
I've added comments whenever this was the case.

Signed-off-by: Chris Blake <redacted>
Signed-off-by: Christian Lamparter <redacted>
---
rfc v1 -> v2:
     - removed PKA (this CryptoPU will need driver)
     - stick with compatibles, nodes, ... from either
       Bluestone (APM82181) or Canyonlands (PPC460EX).
     - add labels for NAND and NOR to help with access.
v2 -> v3:
     - nodename of pciex@d.... was changed to pcie@d..
       due to upstream patch.
     - use simple-bus on the ebc, opb and plb nodes
---
  arch/powerpc/boot/dts/apm82181.dtsi | 466 ++++++++++++++++++++++++++++
  1 file changed, 466 insertions(+)
  create mode 100644 arch/powerpc/boot/dts/apm82181.dtsi

diff --git a/arch/powerpc/boot/dts/apm82181.dtsi b/arch/powerpc/boot/dts/apm82181.dtsi
new file mode 100644
index 000000000000..60283430978d
--- /dev/null
+++ b/arch/powerpc/boot/dts/apm82181.dtsi

@@ -0,0 +1,466 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Device Tree template include for various APM82181 boards.
+ *
+ * The SoC is an evolution of the PPC460EX predecessor.
+ * This is why dt-nodes from the canyonlands EBC, OPB, USB,
+ * DMA, SATA, EMAC, ... ended up in here.
+ *
+ * Copyright (c) 2010, Applied Micro Circuits Corporation
+ * Author: Tirumala R Marri <tmarri@apm.com>,
+ *     Christian Lamparter <chunkeey@gmail.com>,
+ *     Chris Blake <chrisrblake93@gmail.com>
+ */
+
+#include <dt-bindings/dma/dw-dmac.h>
+#include <dt-bindings/input/input.h>
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/gpio/gpio.h>
+
+/ {
+    #address-cells = <2>;
+    #size-cells = <1>;
+    dcr-parent = <&{/cpus/cpu@0}>;
+
+    aliases {
+            ethernet0 = &EMAC0; /* needed for BSP u-boot */
+    };
+
+    cpus {
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            CPU0: cpu@0 {
+                    device_type = "cpu";
+                    model = "PowerPC,apm82181";

This doesn't match the existing bluestone dts file.

Please separate any restructuring from changes.

"I see" (I'm including your comment of the dt-binding as well).

I'm getting the vibe that I better should not touch that bluestone.dts.

I don't know about that.

An honestly, looking at the series and patches that the APM-engineers
posted back in the day, I can see why this well is so poisoned... and
stuff like SATA/AHBDMA/USB/GPIO/CPM/... was missing.

As for the devices. In the spirit of Arnd Bergmann's post of
<https://lkml.org/lkml/2020/3/30/195>

|It would be nice to move over the the bluestone .dts to the apm82181.dtsi file
|when that gets added, if only to ensure they use the same description for each
|node, but that shouldn't stop the addition of the new file if that is needed for
|distros to make use of a popular device.
|I see a couple of additional files in openwrt.

I mean I don't have the bluestone dev board, just the consumer devices.

This stuff is old enough, I'd guess no one cares about a dev board.
But we should figure that out and document that with any changes.

Would it be possible to support those? I can start from a "skeleton" apm82181.dtsi
This would just include CPU, Memory (SD-RAM+L2C+OCM), UIC (Interrupt-Controller),
the PLB+OBP+EBC Busses and UART. Just enough to make a board "boot from ram".

This skeleton would be chunks moved over or duplicated? I don't think
we want 2 of the same thing.

The order I would go is split into an apm82181.dtsi with 0 changes to
the built dtb(s). Then make changes/additions you need. As far as
changes to existing bindings, it's only an ABI if someone notices.


Rob