fpga: region: add compat_id support
This patch introduces a compat_id pointer member and sysfs interface
for each fpga region, similar as compat_id for fpga manager, it allows
applications to read the per region compat_id for compatibility
checking before other actions on this fpga-region (e.g. PR).
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/Documentation/ABI/testing/sysfs-class-fpga-region b/Documentation/ABI/testing/sysfs-class-fpga-region
new file mode 100644
index 0000000..bc7ec644
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-fpga-region
@@ -0,0 +1,9 @@
+What: /sys/class/fpga_region/<region>/compat_id
+Date: June 2018
+KernelVersion: 4.19
+Contact: Wu Hao <hao.wu@intel.com>
+Description: FPGA region id for compatibility check, e.g. compatibility
+ of the FPGA reconfiguration hardware and image. This value
+ is defined or calculated by the layer that is creating the
+ FPGA region. This interface returns the compat_id value or
+ just error code -ENOENT in case compat_id is not used.
