viacuda: implement basic autopolling.

devices/common/adb/adbbus.h

@@ -38,6 +38,7 @@ enum {
     ADB_STAT_OK         = 0,
     ADB_STAT_SRQ_ACTIVE = 1 << 0,
     ADB_STAT_TIMEOUT    = 1 << 1,
+    ADB_STAT_AUTOPOLL   = 1 << 6,
 };
 
 class AdbDevice; // forward declaration to prevent compiler errors

devices/common/viacuda.cpp

@@ -22,6 +22,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 /** High-level VIA-CUDA combo device emulation.
  */
 
+#include <core/hostevents.h>
 #include <core/timermanager.h>
 #include <devices/common/hwinterrupt.h>
 #include <devices/common/viacuda.h>
@@ -79,6 +80,9 @@ ViaCuda::ViaCuda() {
     // establish ADB bus connection
     this->adb_bus_obj = dynamic_cast<AdbBus*>(gMachineObj->get_comp_by_type(HWCompType::ADB_HOST));
 
+    // autopoll handler will be called during post-processing of the host events
+    EventManager::get_instance()->add_post_handler(this, &ViaCuda::autopoll_handler);
+
     this->cuda_init();
 
     this->int_ctrl = nullptr;
@@ -468,6 +472,40 @@ void ViaCuda::process_adb_command() {
     }
 }
 
+void ViaCuda::autopoll_handler() {
+    uint8_t adb_status, output_size;
+
+    if (!this->autopoll_enabled)
+        return;
+
+    // send TALK R0 command to address 3 (mouse)
+    uint8_t in_data[2] = { 0x3C, 0};
+
+    adb_status = this->adb_bus_obj->process_command(in_data, 1);
+
+    if (adb_status == ADB_STAT_OK) {
+        if (!this->old_tip || !this->treq) {
+            LOG_F(WARNING, "Cuda transaction probably in progress");
+        }
+
+        // prepare autopoll packet
+        response_header(CUDA_PKT_ADB, adb_status | ADB_STAT_AUTOPOLL);
+        this->out_buf[2] = 0x3C; // put the proper ADB command
+        output_size = this->adb_bus_obj->get_output_count();
+        if (output_size) {
+            std::memcpy(&this->out_buf[3], this->adb_bus_obj->get_output_buf(), output_size);
+            this->out_count += output_size;
+        }
+
+        // assert TREQ
+        this->via_regs[VIA_B] &= ~CUDA_TREQ;
+        this->treq = 0;
+
+        // draw guest system's attention
+        schedule_sr_int(USECS_TO_NSECS(30));
+    }
+}
+
 void ViaCuda::pseudo_command(int cmd, int data_count) {
     uint16_t    addr;
     int         i;
@@ -476,8 +514,10 @@ void ViaCuda::pseudo_command(int cmd, int data_count) {
     case CUDA_START_STOP_AUTOPOLL:
         if (this->in_buf[2]) {
             LOG_F(INFO, "Cuda: autopoll started, rate: %d ms", this->poll_rate);
+            this->autopoll_enabled = true;
         } else {
             LOG_F(INFO, "Cuda: autopoll stopped");
+            this->autopoll_enabled = false;
         }
         response_header(CUDA_PKT_PSEUDO, 0);
         break;

devices/common/viacuda.h

@@ -223,7 +223,9 @@ private:
     void (ViaCuda::*next_out_handler)(void);
 
     std::unique_ptr<NVram>   pram_obj;
+
     AdbBus* adb_bus_obj = nullptr;
+    bool    autopoll_enabled = false;
 
     // VIA methods
     void print_enabled_ints(); // print enabled VIA interrupts and their sources
@@ -249,6 +251,8 @@ private:
     void out_buf_handler(void);
     void i2c_handler(void);
 
+    void autopoll_handler();
+
     /* I2C related methods */
     void i2c_simple_transaction(uint8_t dev_addr, const uint8_t* in_buf, int in_bytes);
     void i2c_comb_transaction(