sc53c94: support interrupts.

devices/common/scsi/sc53c94.cpp

@@ -23,6 +23,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 #include <core/timermanager.h>
 #include <devices/common/hwcomponent.h>
+#include <devices/common/hwinterrupt.h>
 #include <devices/common/scsi/sc53c94.h>
 #include <loguru.hpp>
 #include <machines/machinebase.h>
@@ -41,6 +42,11 @@ int Sc53C94::device_postinit()
 {
     this->bus_obj = dynamic_cast<ScsiBus*>(gMachineObj->get_comp_by_name("SCSI0"));
     this->bus_obj->register_device(7, static_cast<ScsiDevice*>(this));
+
+    this->int_ctrl = dynamic_cast<InterruptCtrl*>(
+        gMachineObj->get_comp_by_type(HWCompType::INT_CTRL));
+    this->irq_id = this->int_ctrl->register_dev_int(IntSrc::SCSI1);
+
     return 0;
 }
 
@@ -61,17 +67,31 @@ void Sc53C94::reset_device()
     this->data_fifo[0]  = 0;
 
     this->seq_step = 0;
+
+    this->status = 0;
 }
 
 uint8_t Sc53C94::read(uint8_t reg_offset)
 {
+    uint8_t int_status;
+
     switch (reg_offset) {
     case Read::Reg53C94::Command:
         return this->cmd_fifo[0];
     case Read::Reg53C94::Status:
         return this->status;
     case Read::Reg53C94::Int_Status:
-        return this->int_status;
+        int_status = this->int_status;
+        this->seq_step = 0;
+        this->int_status = 0;
+        this->update_irq();
+        return int_status;
+    case Read::Reg53C94::Seq_Step:
+        return this->seq_step;
+    case Read::Reg53C94::FIFO_Flags:
+        return (this->seq_step << 5) | (this->data_fifo_pos & 0x1F);
+    case Read::Reg53C94::Config_3:
+        return this->config3;
     case Read::Reg53C94::Xfer_Cnt_Hi:
         if (this->config2 & CFG2_ENF) {
             return (this->xfer_count >> 16) & 0xFFU;
@@ -197,7 +217,7 @@ void Sc53C94::exec_command()
         break;
     case CMD_SELECT_NO_ATN:
         static SeqDesc sel_no_atn_desc[] {
-            {SeqState::SEL_BEGIN,    2, INTSTAT_SR | INTSTAT_SO},
+            {SeqState::SEL_BEGIN,    0, INTSTAT_DIS            },
             {SeqState::CMD_BEGIN,    3, INTSTAT_SR | INTSTAT_SO},
             {SeqState::CMD_COMPLETE, 4, INTSTAT_SR | INTSTAT_SO},
         };
@@ -207,6 +227,10 @@ void Sc53C94::exec_command()
         sequencer();
         LOG_F(INFO, "SC53C94: SELECT W/O ATN command started");
         break;
+    case CMD_ENA_SEL_RESEL:
+        LOG_F(INFO, "SC53C94: ENABLE SELECTION/RESELECTION command executed");
+        exec_next_command();
+        break;
     default:
         LOG_F(ERROR, "SC53C94: invalid/unimplemented command 0x%X", cmd);
         this->cmd_fifo_pos--; // remove invalid command from FIFO
@@ -296,8 +320,9 @@ void Sc53C94::sequencer()
         } else { // selection timeout
             this->seq_step = this->cmd_steps->step_num;
             this->int_status |= this->cmd_steps->status;
-            this->bus_obj->release_ctrl_lines(this->my_bus_id);
+            this->bus_obj->disconnect(this->my_bus_id);
             this->cur_state = SeqState::IDLE;
+            this->update_irq();
             exec_next_command();
         }
         break;
@@ -306,6 +331,16 @@ void Sc53C94::sequencer()
     }
 }
 
+void Sc53C94::update_irq()
+{
+    uint8_t new_irq = !!(this->int_status != 0);
+    if (new_irq != this->irq) {
+        this->irq = new_irq;
+        this->status = (this->status & 0x7F) | (new_irq << 7);
+        this->int_ctrl->ack_int(this->irq_id, new_irq);
+    }
+}
+
 void Sc53C94::notify(ScsiMsg msg_type, int param)
 {
     switch (msg_type) {

devices/common/scsi/sc53c94.h

@@ -30,6 +30,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #define SC_53C94_H
 
 #include "scsi.h"
+#include "devices/common/hwinterrupt.h"
 
 #include <cinttypes>
 
@@ -82,6 +83,7 @@ enum {
     CMD_RESET_BUS     =    3,
     CMD_DMA_STOP      =    4,
     CMD_SELECT_NO_ATN = 0x41,
+    CMD_ENA_SEL_RESEL = 0x44,
 };
 
 /** Interrupt status register bits. */
@@ -146,6 +148,8 @@ protected:
     void sequencer();
     void seq_defer_state(uint64_t delay_ns);
 
+    void update_irq();
+
 private:
     uint8_t     chip_id;
     uint8_t     my_bus_id;
@@ -177,6 +181,11 @@ private:
     SeqDesc*    cmd_steps;
     bool        is_initiator;
     uint8_t     cur_cmd;
+
+    // interrupt related stuff
+    InterruptCtrl* int_ctrl = nullptr;
+    uint32_t       irq_id   = 0;
+    uint8_t        irq      = 0;
 };
 
 #endif // SC_53C94_H

devices/common/scsi/scsi.h

@@ -90,7 +90,7 @@ public:
     void assert_ctrl_line(int id, uint16_t mask);
     void release_ctrl_line(int id, uint16_t mask);
     void release_ctrl_lines(int id);
-    int current_phase() { return this->cur_phase; };
+    int  current_phase() { return this->cur_phase; };
 
     // high-level control/status
     bool begin_arbitration(int id);
@@ -98,6 +98,7 @@ public:
     bool begin_selection(int initiator_id, int target_id, bool atn);
     void confirm_selection(int target_id);
     bool end_selection(int initiator_id, int target_id);
+    void disconnect(int dev_id);
 
 protected:
     void change_bus_phase(int initiator_id);

devices/common/scsi/scsi_bus.cpp

@@ -170,3 +170,12 @@ bool ScsiBus::end_selection(int initiator_id, int target_id)
     // check for selection confirmation from target
     return this->target_id == target_id;
 }
+
+void ScsiBus::disconnect(int dev_id)
+{
+    this->release_ctrl_lines(dev_id);
+    if (!(this->ctrl_lines & SCSI_CTRL_BSY) && !(this->ctrl_lines & SCSI_CTRL_SEL)) {
+        this->cur_phase = ScsiPhase::BUS_FREE;
+        change_bus_phase(dev_id);
+    }
+}