Hi Ben,

On 24/07/2025 11:56, Ben Horgan wrote:

On 11/07/2025 19:36, James Morse wrote:

quoted

commit 363c8aea257 "platform: Add ARM64 platform directory" added a
subdirectory for arm64 platform devices, but claims that all such
devices must be 'EC like'.

The arm64 MPAM driver manages an MMIO interface that appears in memory
controllers, caches, IOMMU and connection points on the interconnect.
It doesn't fit into any existing subsystem.

It would be convenient to use this subdirectory for drivers for other
arm64 platform devices which aren't closely coupled to the architecture
code and don't fit into any existing subsystem.

Move the existing code and maintainer entries to be under
drivers/platform/arm64/ec. The MPAM driver will be added under
drivers/platform/arm64/mpam.

quoted

diff --git a/drivers/platform/arm64/ec/Kconfig b/drivers/platform/arm64/ec/Kconfig
new file mode 100644
index 000000000000..06288aebc559
--- /dev/null
+++ b/drivers/platform/arm64/ec/Kconfig

@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# EC-like Drivers for aarch64 based devices.
+#
+
+menuconfig ARM64_PLATFORM_DEVICES
+    bool "ARM64 Platform-Specific Device Drivers"
+    depends on ARM64 || COMPILE_TEST
+    default ARM64
+    help
+      Say Y here to get to see options for platform-specific device drivers
+      for arm64 based devices, primarily EC-like device drivers.
+      This option alone does not add any kernel code.
+
+      If you say N, all options in this submenu will be skipped and disabled.
+
+if ARM64_PLATFORM_DEVICES

Shouldn't this be kept in the directory above? By the description this would be expected
to apply to all drivers in drivers/platfrom/arm64.

Doing that makes any MPAM options appear under 'Platform-Specific Device Drivers' too. I
didn't to that as MPAM isn't specific to one platform, but doesn't fit under any of the
bus or high level groups under drivers. (I briefly toyed with drivers/perf - as there
isn't a drivers/qos).


Thanks,

James