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authorRob Herring (Arm) <robh@kernel.org>2026-08-31 14:43:51 -0500
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2026-09-13 18:17:31 -0700
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Input: tsc2007 - read "ti,poll-period" as u32grafted
The "ti,poll-period" property is documented as a normal uint32 cell. The driver used a u64 helper, which makes the helper type disagree with the schema even though the stored value is still small. Read "ti,poll-period" with the u32 helper matching the documented DT cell size. Assisted-by: Codex:gpt-5-5 Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Link: https://patch.msgid.link/20260831194352.1185860-1-robh@kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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+Introduction
+============
+
+The FPGA subsystem supports reprogramming FPGAs dynamically under
+Linux. Some of the core intentions of the FPGA subsystems are:
+
+* The FPGA subsystem is vendor agnostic.
+
+* The FPGA subsystem separates upper layers (userspace interfaces and
+ enumeration) from lower layers that know how to program a specific
+ FPGA.
+
+* Code should not be shared between upper and lower layers. This
+ should go without saying. If that seems necessary, there's probably
+ framework functionality that can be added that will benefit
+ other users. Write the linux-fpga mailing list and maintainers and
+ seek out a solution that expands the framework for broad reuse.
+
+* Generally, when adding code, think of the future. Plan for reuse.
+
+The framework in the kernel is divided into:
+
+FPGA Manager
+------------
+
+If you are adding a new FPGA or a new method of programming an FPGA,
+this is the subsystem for you. Low level FPGA manager drivers contain
+the knowledge of how to program a specific device. This subsystem
+includes the framework in fpga-mgr.c and the low level drivers that
+are registered with it.
+
+FPGA Bridge
+-----------
+
+FPGA Bridges prevent spurious signals from going out of an FPGA or a
+region of an FPGA during programming. They are disabled before
+programming begins and re-enabled afterwards. An FPGA bridge may be
+actual hard hardware that gates a bus to a CPU or a soft ("freeze")
+bridge in FPGA fabric that surrounds a partial reconfiguration region
+of an FPGA. This subsystem includes fpga-bridge.c and the low level
+drivers that are registered with it.
+
+FPGA Region
+-----------
+
+If you are adding a new interface to the FPGA framework, add it on top
+of an FPGA region.
+
+The FPGA Region framework (fpga-region.c) associates managers and
+bridges as reconfigurable regions. A region may refer to the whole
+FPGA in full reconfiguration or to a partial reconfiguration region.
+
+The Device Tree FPGA Region support (of-fpga-region.c) handles
+reprogramming FPGAs when device tree overlays are applied.