Add IPMI BT IRQ support

ipmi_bt_slave.v

@@ -74,6 +74,7 @@ module ipmi_bt_slave_interface(
 	reg host_to_bmc_ctl_attn_req_cont_reg = 0;
 	reg bmc_to_host_ctl_attn_ack_cont_reg = 0;
 
+	reg irq_ack_cont_reg = 0;
 	reg irq_bmc_reset_cont_reg = 0;
 	reg irq_req_reg = 0;
 
@@ -92,6 +93,7 @@ module ipmi_bt_slave_interface(
 	assign host_to_bmc_ctl_attn_req_cont = host_to_bmc_ctl_attn_req_cont_reg;
 	assign bmc_to_host_ctl_attn_ack_cont = bmc_to_host_ctl_attn_ack_cont_reg;
 
+	assign irq_ack_cont = irq_ack_cont_reg;
 	assign irq_bmc_reset_cont = irq_bmc_reset_cont_reg;
 	assign irq_req = irq_req_reg;
 
@@ -324,6 +326,7 @@ module ipmi_bt_slave_interface(
 	reg [1:0] hiomap_window_type = HIOMAP_WINDOW_TYPE_READ;
 
 	reg host_to_bmc_ctl_attn_req_prev = 0;
+	reg bmc_to_host_ctl_attn_req_prev = 0;
 
 	assign debug_port = ipmi_transfer_state;
 
@@ -1902,6 +1905,26 @@ module ipmi_bt_slave_interface(
 				end
 			endcase
 
+			// IRQ handler
+			if (irq_ack) begin
+				irq_req_reg <= 0;
+				irq_ack_cont_reg <= 1;
+			end else begin
+				if (!irq_ack_cont_reg) begin
+					if (!irq_ack_cont_reg && !bmc_to_host_ctl_attn_req_prev && bmc_to_host_ctl_attn_req) begin
+						irq_req_reg <= 1;
+					end
+				end else begin
+					irq_ack_cont_reg <= 0;
+				end
+			end
+			if (!irq_ack_cont_reg) begin
+				// Wait for prior IRQ line handshake to complete before sampling the B2H_ATN line
+				// This ensures that the IRQ is still fired if the continue signal is asserted while
+				// B2H_ATN transitions from inactive to active.
+				bmc_to_host_ctl_attn_req_prev <= bmc_to_host_ctl_attn_req;
+			end
+
 			host_to_bmc_ctl_attn_req_prev <= host_to_bmc_ctl_attn_req;
 		end
 

main.v

@@ -110,12 +110,14 @@ module lpc_bridge_top(
 	parameter DEBUG_PORT_ADDRESS_HIGH = 16'h0081;
 	parameter DEBUG_PORT_ADDRESS_LOW = 16'h0082;
 	parameter IPMI_BT_PORT_BASE_ADDRESS = 16'h00e4;
+	parameter IPMI_BT_IRQ = 10;
 	parameter HOST_UART_BASE_ADDRESS = 16'h03f8;
 	parameter HOST_UART_IRQ = 4;
 `else
 	parameter DEBUG_PORT_ADDRESS_HIGH = 16'h0083;
 	parameter DEBUG_PORT_ADDRESS_LOW = 16'h0084;
 	parameter IPMI_BT_PORT_BASE_ADDRESS = 16'h00d4;
+	parameter IPMI_BT_IRQ = 11;
 	parameter HOST_UART_BASE_ADDRESS = 16'h02f8;
 	parameter HOST_UART_IRQ = 3;
 `endif
@@ -2207,7 +2209,8 @@ module lpc_bridge_top(
 `ifdef ENABLE_SERIAL_IRQ_SUPPORT
 		// Handle IRQ lines
 		// WARNING: This works for continous mode only!
-		// For quiet mode, each assert / deassert needs to be specifically handled by strobing lpc_slave_irq_tx_ready on IRQ status change
+		// For quiet mode, each assert / deassert needs to be specifically handled by strobing ipmi_bt_irq_req / lpc_slave_irq_tx_ready on IRQ status change
+		lpc_slave_irq_request[IPMI_BT_IRQ] = ipmi_bt_irq_req;
 		lpc_slave_irq_request[HOST_UART_IRQ] = host_uart_3f8_irq;
 `endif