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authorMark Brown <broonie@kernel.org>2026-05-29 18:09:08 +0100
committerMark Brown <broonie@kernel.org>2026-05-29 18:09:08 +0100
commitd668848e9d7fc23918835b741cc350cddb14b483 (patch)
tree26a0d93ca6c1e79f59059d0f5e0e2be067bd8dd6 /Documentation
parenta3f2fd910514c1df8adf5869c587d9cd9ac77ba1 (diff)
parent47d7bca76dd4f36ba0525d761f247c76ec9e4b17 (diff)
downloadlinux-next-history-d668848e9d7fc23918835b741cc350cddb14b483.tar.gz
Merge branch 'for-next' of https://github.com/Xilinx/linux-xlnx.git
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-driver-firmware-zynqmp33
1 files changed, 33 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
index c3fec3c835af3..ac8c2314deee2 100644
--- a/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
+++ b/Documentation/ABI/stable/sysfs-driver-firmware-zynqmp
@@ -254,3 +254,36 @@ Description:
The expected result is 500.
Users: Xilinx
+
+What: /sys/devices/platform/firmware\:zynqmp-firmware/csu_registers/*
+Date: May 2026
+KernelVersion: 7.2
+Contact: "Ronak Jain" <ronak.jain@amd.com>
+Description:
+ Read/Write CSU (Configuration Security Unit) registers.
+
+ This interface provides dynamic access to CSU registers that are
+ discovered from the firmware at boot time using PM_QUERY_DATA API.
+
+ The supported registers are:
+
+ - multiboot: CSU_MULTI_BOOT register
+ - idcode: CSU_IDCODE register (read-only)
+ - pcap-status: CSU_PCAP_STATUS register (read-only)
+
+ Read operations use the existing IOCTL_READ_REG API.
+ Write operations use the existing IOCTL_MASK_WRITE_REG API.
+
+ The firmware enforces access control - read-only registers will reject
+ write attempts even though the sysfs permissions show write access.
+
+ Usage for reading::
+
+ # cat /sys/devices/platform/firmware\:zynqmp-firmware/csu_registers/multiboot
+ # cat /sys/devices/platform/firmware\:zynqmp-firmware/csu_registers/idcode
+
+ Usage for writing (mask and value are in hexadecimal)::
+
+ # echo 0xFFFFFFF 0x0 > /sys/devices/platform/firmware\:zynqmp-firmware/csu_registers/multiboot
+
+Users: Xilinx/AMD