fpga_spn: use separate reset for DMA

fpga_spn/src/init.h

@@ -13,6 +13,7 @@ typedef void (*function_ptr_t) (void);
 plic_instance_t g_plic;
 std::array<function_ptr_t,PLIC_NUM_INTERRUPTS>  g_ext_interrupt_handlers;
 bool hw_interrupt{true};
+bool dma_interrupt{true};
 
 
 /*! \brief external interrupt handler
@@ -43,11 +44,7 @@ void configure_irq(size_t irq_num, function_ptr_t handler, unsigned char prio=1)
     PLIC_enable_interrupt(&g_plic, irq_num);
 }
 
-static void msi_interrupt_handler(){
-	hw_interrupt = false;
-}
-
-void wait_for_interrupt() {
+void wait_for_spn_interrupt() {
     // wait until HW is done
     if(hw_interrupt) {
         do{
@@ -58,6 +55,17 @@ void wait_for_interrupt() {
 	hw_interrupt=true;
 }
 
+void wait_for_dma_interrupt() {
+    // wait until HW is done
+    if(dma_interrupt) {
+        do{
+            asm("wfi");
+            asm("nop");
+        }while(dma_interrupt);
+    }
+    dma_interrupt=true;
+}
+
 /*!\brief initializes platform
  *
  */
@@ -77,7 +85,6 @@ void platform_init(){
     clear_csr(mie, MIP_MEIP);
     clear_csr(mie, MIP_MTIP);
     for (auto& h:g_ext_interrupt_handlers) h=no_interrupt_handler;
-    configure_irq(2, msi_interrupt_handler);
     // Enable interrupts in general.
     set_csr(mstatus, MSTATUS_MIE);
     // Enable the Machine-External bit in MIE

fpga_spn/src/raven_spn.cpp

@@ -25,10 +25,20 @@ void fpga_dma(int direction, int fpga_address, int sc_address, int num_bytes) {
     dma::sc_address_reg() = sc_address;
     dma::bytes_reg() = num_bytes;
     dma::start_reg() = 1;
-    wait_for_interrupt();
+    wait_for_dma_interrupt();
     dma::clear_interrupt_reg() = 1;
 }
 
+static void spn_interrupt_handler(){
+    printf("spn_interrupt_handler\n");
+    hw_interrupt = false;
+}
+
+static void dma_interrupt_handler(){
+    printf("dma_interrupt_handler\n");
+    dma_interrupt = false;
+}
+
 /*! \brief main function
  *
  */
@@ -36,10 +46,12 @@ int main() {
 
 
     platform_init();
+    configure_irq(2, spn_interrupt_handler);
+    configure_irq(22, dma_interrupt_handler);
 
     spn::mode_reg() = 1;
     spn::start_reg() = 1;
-    wait_for_interrupt();
+    wait_for_spn_interrupt();
     spn::interrupt_reg() = 1;
     uint32_t readout = spn::readout_reg();
     printf("READOUT HW:0x%x\n", readout);
@@ -60,8 +72,8 @@ int main() {
 
     printf("Result Bytes: %d\n", result_bytes);
 
-    uint32_t step = 10000;
-    uint32_t iterations = 5;
+    uint32_t step = 50000;
+    uint32_t iterations = 2;
 
     
     uint32_t in_beats = (step * sample_bytes) / axi_bytes;
@@ -84,7 +96,7 @@ int main() {
     for (int k = 0; k < iterations*step; k+=step) {
         fpga_dma(1, fpga_address_in, in_addr, step * sample_bytes);
         run_xspn(fpga_address_in, fpga_address_out, step, in_beats, out_beats);
-        wait_for_interrupt();
+        wait_for_spn_interrupt();
         spn::interrupt_reg() = 1;
         printf("XSPN finished\n");
         fpga_dma(0, fpga_address_out, out_addr, step * result_bytes);