nds32: Remove the architecture

The nds32 architecture, also known as AndeStar V3, is a custom 32-bit
RISC target designed by Andes Technologies. Support was added to the
kernel in 2016 as the replacement RISC-V based V5 processors were
already announced, and maintained by (current or former) Andes
employees.

As explained by Alan Kao, new customers are now all using RISC-V,
and all known nds32 users are already on longterm stable kernels
provided by Andes, with no development work going into mainline
support any more.

While the port is still in a reasonably good shape, it only gets
worse over time without active maintainers, so it seems best
to remove it before it becomes unusable. As always, if it turns
out that there are mainline users after all, and they volunteer
to maintain the port in the future, the removal can be reverted.

Link: https://lore.kernel.org/linux-mm/YhdWNLUhk+x9RAzU@yamatobi.andestech.com/
Link: https://lore.kernel.org/lkml/20220302065213.82702-1-alankao@andestech.com/
Link: https://www.andestech.com/en/products-solutions/andestar-architecture/
Signed-off-by: Alan Kao <alankao@andestech.com>
[arnd: rewrite changelog to provide more background]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 0 insertions, 106 deletions

diff --git a/Documentation/devicetree/bindings/nds32/andestech-boards b/Documentation/devicetree/bindings/nds32/andestech-boards
deleted file mode 100644
index f5d75693e3c7..000000000000
--- a/Documentation/devicetree/bindings/nds32/andestech-boards
+++ /dev/null
@@ -1,40 +0,0 @@
-Andestech(nds32) AE3XX Platform
------------------------------------------------------------------------------
-The AE3XX prototype demonstrates the AE3XX example platform on the FPGA. It
-is composed of one Andestech(nds32) processor and AE3XX.
-
-Required properties (in root node):
-- compatible = "andestech,ae3xx";
-
-Example:
-/dts-v1/;
-/ {
-	compatible = "andestech,ae3xx";
-	#address-cells = <1>;
-	#size-cells = <1>;
-	interrupt-parent = <&intc>;
-};
-
-Andestech(nds32) AG101P Platform
------------------------------------------------------------------------------
-AG101P is a generic SoC Platform IP that works with any of Andestech(nds32)
-processors to provide a cost-effective and high performance solution for
-majority of embedded systems in variety of application domains. Users may
-simply attach their IP on one of the system buses together with certain glue
-logics to complete a SoC solution for a specific application. With
-comprehensive simulation and design environments, users may evaluate the
-system performance of their applications and track bugs of their designs
-efficiently. The optional hardware development platform further provides real
-system environment for early prototyping and software/hardware co-development.
-
-Required properties (in root node):
-	compatible = "andestech,ag101p";
-
-Example:
-/dts-v1/;
-/ {
-	compatible = "andestech,ag101p";
-	#address-cells = <1>;
-	#size-cells = <1>;
-	interrupt-parent = <&intc>;
-};
diff --git a/Documentation/devicetree/bindings/nds32/atl2c.txt b/Documentation/devicetree/bindings/nds32/atl2c.txt
deleted file mode 100644
index da8ab8e7ae9b..000000000000
--- a/Documentation/devicetree/bindings/nds32/atl2c.txt
+++ /dev/null
@@ -1,28 +0,0 @@
-* Andestech L2 cache Controller
-
-The level-2 cache controller plays an important role in reducing memory latency
-for high performance systems, such as thoese designs with AndesCore processors.
-Level-2 cache controller in general enhances overall system performance
-signigicantly and the system power consumption might be reduced as well by
-reducing DRAM accesses.
-
-This binding specifies what properties must be available in the device tree
-representation of an Andestech L2 cache controller.
-
-Required properties:
-	- compatible:
-		Usage: required
-		Value type: <string>
-		Definition: "andestech,atl2c"
-	- reg : Physical base address and size of cache controller's memory mapped
-	- cache-unified : Specifies the cache is a unified cache.
-	- cache-level : Should be set to 2 for a level 2 cache.
-
-* Example
-
-	cache-controller@e0500000 {
-		compatible = "andestech,atl2c";
-		reg = <0xe0500000 0x1000>;
-		cache-unified;
-		cache-level = <2>;
-	};
diff --git a/Documentation/devicetree/bindings/nds32/cpus.txt b/Documentation/devicetree/bindings/nds32/cpus.txt
deleted file mode 100644
index 6f9e311b6589..000000000000
--- a/Documentation/devicetree/bindings/nds32/cpus.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-* Andestech Processor Binding
-
-This binding specifies what properties must be available in the device tree
-representation of a Andestech Processor Core, which is the root node in the
-tree.
-
-Required properties:
-
-	- compatible:
-		Usage: required
-		Value type: <string>
-		Definition: Should be "andestech,<core_name>", "andestech,nds32v3" as fallback.
-		Must contain "andestech,nds32v3" as the most generic value, in addition to
-		one of the following identifiers for a particular CPU core:
-		"andestech,n13"
-		"andestech,n15"
-		"andestech,d15"
-		"andestech,n10"
-		"andestech,d10"
-	- device_type
-		Usage: required
-		Value type: <string>
-		Definition: must be "cpu"
-	- reg: Contains CPU index.
-	- clock-frequency: Contains the clock frequency for CPU, in Hz.
-
-* Examples
-
-/ {
-	cpus {
-		cpu@0 {
-			device_type = "cpu";
-			compatible = "andestech,n13", "andestech,nds32v3";
-			reg = <0x0>;
-			clock-frequency = <60000000>
-		};
-	};
-};