packet_filter: Initial commit

- Added packet filter base class
- Updated publisher with the filter class

Signed-off-by: Istvan-Zsolt Szekely <istvan.szekely@analog.com>

Author: IstvanZsSzekely

library/utilities/filter_pkg.sv

@@ -0,0 +1,58 @@
+// ***************************************************************************
+// ***************************************************************************
+// Copyright (C) 2025 Analog Devices, Inc. All rights reserved.
+//
+// In this HDL repository, there are many different and unique modules, consisting
+// of various HDL (Verilog or VHDL) components. The individual modules are
+// developed independently, and may be accompanied by separate and unique license
+// terms.
+//
+// The user should read each of these license terms, and understand the
+// freedoms and responsabilities that he or she has by using this source/core.
+//
+// This core is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+// A PARTICULAR PURPOSE.
+//
+// Redistribution and use of source or resulting binaries, with or without modification
+// of this file, are permitted under one of the following two license terms:
+//
+//   1. The GNU General Public License version 2 as published by the
+//      Free Software Foundation, which can be found in the top level directory
+//      of this repository (LICENSE_GPL2), and also online at:
+//      <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html>
+//
+// OR
+//
+//   2. An ADI specific BSD license, which can be found in the top level directory
+//      of this repository (LICENSE_ADIBSD), and also on-line at:
+//      https://github.com/analogdevicesinc/hdl/blob/main/LICENSE_ADIBSD
+//      This will allow to generate bit files and not release the source code,
+//      as long as it attaches to an ADI device.
+//
+// ***************************************************************************
+// ***************************************************************************
+
+`include "utils.svh"
+
+package filter_pkg;
+
+  import logger_pkg::*;
+  import adi_common_pkg::*;
+
+  class adi_filter #(type data_type = int) extends adi_component;
+
+    function new(
+      input string name,
+      input adi_component parent = null);
+
+      super.new(name, parent);
+    endfunction: new
+
+    virtual function bit filter(input data_type data [$]);
+      return 1'b0;
+    endfunction: filter
+
+  endclass: adi_filter
+
+endpackage

library/utilities/pub_sub_pkg.sv

@@ -66,30 +66,48 @@ package pub_sub_pkg;
 
     protected adi_subscriber #(data_type) subscriber_list[bit[15:0]];
 
+    protected adi_filter #(data_type) filter;
+
     function new(
       input string name,
       input adi_component parent = null);
 
       super.new(name, parent);
     endfunction: new
+    
+    function void setup_filter(input adi_filter #(data_type) filter);
+      this.filter = filter;
+    endfunction: setup_filter
+
+    function void remove_filter();
+      this.filter = null;
+    endfunction: remove_filter
 
     function void subscribe(input adi_subscriber #(data_type) subscriber);
-      if (this.subscriber_list.exists(subscriber.id))
+      if (this.subscriber_list.exists(subscriber.id)) begin
         this.error($sformatf("Subscriber already on the list!"));
-      else
+      end else begin
         this.subscriber_list[subscriber.id] = subscriber;
+      end
     endfunction: subscribe
 
     function void unsubscribe(input adi_subscriber #(data_type) subscriber);
-      if (!this.subscriber_list.exists(subscriber.id))
+      if (!this.subscriber_list.exists(subscriber.id)) begin
         this.error($sformatf("Subscriber does not exist on list!"));
-      else
+      end else begin
         this.subscriber_list.delete(subscriber.id);
+      end
     endfunction: unsubscribe
 
     function void notify(input data_type data [$]);
-      foreach (this.subscriber_list[i])
+      if (this.filter != null) begin
+        if (!this.filter.filter(data)) begin
+          return;
+        end
+      end
+      foreach (this.subscriber_list[i]) begin
         this.subscriber_list[i].update(data);
+      end
     endfunction: notify
 
   endclass: adi_publisher