From 6d77d9deb2457b4aea0bc59e7e2c0826f79cd1b9 Mon Sep 17 00:00:00 2001
From: Karol Gugala <kgugala@antmicro.com>
Date: Thu, 9 Jan 2025 22:03:33 +0100
Subject: [PATCH] recovery: clear tx_desc on recovery mode enter

---
 src/ctrl/controller.sv             |  6 ++++--
 src/ctrl/controller_standby.sv     |  6 ++++--
 src/ctrl/controller_standby_i3c.sv |  8 ++++++--
 src/ctrl/descriptor_tx.sv          | 11 +++++++++--
 src/i3c.sv                         |  8 ++++++--
 src/recovery/recovery_handler.sv   | 14 +++++++++++++-
 6 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/src/ctrl/controller.sv b/src/ctrl/controller.sv
index 9094416f..e4be7b54 100644
--- a/src/ctrl/controller.sv
+++ b/src/ctrl/controller.sv
@@ -234,7 +234,8 @@ module controller
     input  logic peripheral_reset_done_i,
     output logic escalated_reset_o,
 
-    output logic err_o
+    output logic err_o,
+    input recovery_mode_enter_i
 );
 
   logic phy_en;
@@ -515,7 +516,8 @@ module controller
       .mrl_o(mrl),
       .peripheral_reset_o,
       .peripheral_reset_done_i,
-      .escalated_reset_o
+      .escalated_reset_o,
+      .recovery_mode_enter_i(recovery_mode_enter_i)
   );
 
 endmodule
diff --git a/src/ctrl/controller_standby.sv b/src/ctrl/controller_standby.sv
index ff62b5fa..4b3caf11 100644
--- a/src/ctrl/controller_standby.sv
+++ b/src/ctrl/controller_standby.sv
@@ -163,7 +163,8 @@ module controller_standby
     input  logic peripheral_reset_done_i,
     output logic escalated_reset_o,
 
-    output logic err_o
+    output logic err_o,
+    input  recovery_mode_enter_i
 );
 
   logic sel_i2c_i3c;  // i2c = 0; i3c = 1;
@@ -408,7 +409,8 @@ module controller_standby
       .parity_err_o(parity_err),
       .peripheral_reset_o,
       .peripheral_reset_done_i,
-      .escalated_reset_o
+      .escalated_reset_o,
+      .recovery_mode_enter_i(recovery_mode_enter_i)
   );
 
 endmodule
diff --git a/src/ctrl/controller_standby_i3c.sv b/src/ctrl/controller_standby_i3c.sv
index 9653a017..afa288a8 100644
--- a/src/ctrl/controller_standby_i3c.sv
+++ b/src/ctrl/controller_standby_i3c.sv
@@ -120,7 +120,10 @@ module controller_standby_i3c
 
     output logic peripheral_reset_o,
     input  logic peripheral_reset_done_i,
-    output logic escalated_reset_o
+    output logic escalated_reset_o,
+
+    // recovery mode
+    input recovery_mode_enter_i
 );
   logic i3c_standby_en;
   assign i3c_standby_en = i3c_standby_en_i;
@@ -674,7 +677,8 @@ module controller_standby_i3c
       .tx_byte_last_o            (tx_last_byte),
       .tx_byte_valid_o           (tx_fifo_rvalid),
       .tx_byte_ready_i           (tx_fifo_rready),
-      .tx_byte_err_i             (tx_host_nack)
+      .tx_byte_err_i             (tx_host_nack),
+      .recovery_mode_enter_i     (recovery_mode_enter_i)
   );
 
   descriptor_ibi #(
diff --git a/src/ctrl/descriptor_tx.sv b/src/ctrl/descriptor_tx.sv
index 4c401d2e..3b4d56e6 100644
--- a/src/ctrl/descriptor_tx.sv
+++ b/src/ctrl/descriptor_tx.sv
@@ -36,7 +36,10 @@ module descriptor_tx #(
     output logic tx_byte_last_o,
     output logic tx_byte_valid_o,
     input logic tx_byte_ready_i,
-    input logic tx_byte_err_i
+    input logic tx_byte_err_i,
+
+    // recovery mode
+    input recovery_mode_enter_i
 );
 
   logic [31:0] tx_descriptor;
@@ -56,10 +59,14 @@ module descriptor_tx #(
       tx_descriptor <= '0;
     end else begin
       if (tx_end) descriptor_valid <= '0;
-      else if (tti_tx_desc_queue_rready_o) begin
+      else if (tti_tx_desc_queue_rready_o && !recovery_mode_enter_i) begin
         tx_descriptor <= tti_tx_desc_queue_rdata_i;
         descriptor_valid <= '1;
       end
+      else if (recovery_mode_enter_i) begin
+        descriptor_valid <= '0;
+        tx_descriptor <= '0;
+      end
     end
   end
 
diff --git a/src/i3c.sv b/src/i3c.sv
index c8ae3c64..c0cdc421 100644
--- a/src/i3c.sv
+++ b/src/i3c.sv
@@ -496,6 +496,8 @@ module i3c
 
   logic controller_error;
 
+  logic recovery_mode_enter;
+
   controller #(
       .DatAw(DatAw),
       .DctAw(DctAw)
@@ -672,7 +674,8 @@ module i3c
       .peripheral_reset_done_i,
       .escalated_reset_o,
 
-      .err_o(controller_error)
+      .err_o(controller_error),
+      .recovery_mode_enter_i(recovery_mode_enter)
   );
 
   // HCI
@@ -1062,7 +1065,8 @@ module i3c
 
       // Received I2C/I3C address along with RnW# bit
       .ctl_bus_addr_i(rx_bus_addr),
-      .ctl_bus_addr_valid_i(rx_bus_addr_valid)
+      .ctl_bus_addr_valid_i(rx_bus_addr_valid),
+      .recovery_mode_enter_o(recovery_mode_enter)
   );
 
   // I3C PHY
diff --git a/src/recovery/recovery_handler.sv b/src/recovery/recovery_handler.sv
index cea18495..84c6da5f 100644
--- a/src/recovery/recovery_handler.sv
+++ b/src/recovery/recovery_handler.sv
@@ -171,17 +171,29 @@ module recovery_handler
 
     // Recovery status
     output logic payload_available_o,
-    output logic image_activated_o
+    output logic image_activated_o,
+    output logic recovery_mode_enter_o
 );
   assign irq_o = '0;
 
   // ....................................................
 
   logic recovery_enable;
+  logic [1:0] recovery_mode_enter_shreg;
   localparam int unsigned RecoveryMode = 'h3;
 
   assign recovery_enable = hwif_rec_i.DEVICE_STATUS_0.PLACEHOLDER.value[7:0] == RecoveryMode;
 
+  // generate recovery enter pulse
+  assign recovery_mode_enter_o = recovery_mode_enter_shreg[0];
+  always @(posedge clk_i or negedge rst_ni)
+    if (~rst_ni) begin
+      recovery_mode_enter_shreg <= 2'b10;
+    end else if (recovery_enable) begin
+      recovery_mode_enter_shreg <= {1'b0, recovery_mode_enter_shreg[1]};
+    end else begin
+      recovery_mode_enter_shreg <= 2'b10;
+    end
   // ....................................................
   // TTI Queues