PAD: Basic support for digital controllers

src/pse/pad.cpp

@@ -0,0 +1,172 @@
+#include "pad.h"
+#include "YBaseLib/Log.h"
+#include "common/state_wrapper.h"
+#include "interrupt_controller.h"
+#include "pad_device.h"
+Log_SetChannel(Pad);
+
+Pad::Pad() = default;
+
+Pad::~Pad() = default;
+
+bool Pad::Initialize(InterruptController* interrupt_controller)
+{
+  m_interrupt_controller = interrupt_controller;
+  return true;
+}
+
+void Pad::Reset()
+{
+  SoftReset();
+}
+
+bool Pad::DoState(StateWrapper& sw)
+{
+  return !sw.HasError();
+}
+
+u32 Pad::ReadRegister(u32 offset)
+{
+  switch (offset)
+  {
+    case 0x00: // JOY_DATA
+    {
+      if (m_RX_FIFO.IsEmpty())
+      {
+        Log_WarningPrint("Read from RX fifo when empty");
+        return 0;
+      }
+
+      const u8 value = m_RX_FIFO.Pop();
+      UpdateJoyStat();
+      Log_DebugPrintf("JOY_DATA (R) -> 0x%02X", ZeroExtend32(value));
+      return ZeroExtend32(value);
+    }
+
+    case 0x04: // JOY_STAT
+      return m_JOY_STAT.bits;
+
+    case 0x08: // JOY_MODE
+      return ZeroExtend32(m_JOY_MODE.bits);
+
+    case 0x0A: // JOY_CTRL
+      return ZeroExtend32(m_JOY_CTRL.bits);
+
+    default:
+      Log_ErrorPrintf("Unknown register read: 0x%X", offset);
+      return UINT32_C(0xFFFFFFFF);
+  }
+}
+
+void Pad::WriteRegister(u32 offset, u32 value)
+{
+  switch (offset)
+  {
+    case 0x00: // JOY_DATA
+    {
+      Log_DebugPrintf("JOY_DATA (W) <- 0x%02X", value);
+      if (m_TX_FIFO.IsFull())
+      {
+        Log_WarningPrint("TX FIFO overrun");
+        m_TX_FIFO.RemoveOne();
+      }
+
+      m_TX_FIFO.Push(Truncate8(value));
+
+      if (m_JOY_CTRL.SELECT)
+        DoTransfer();
+
+      return;
+    }
+
+    case 0x0A: // JOY_CTRL
+    {
+      Log_DebugPrintf("JOY_CTRL <- 0x%04X", value);
+      const bool old_select = m_JOY_CTRL.SELECT;
+
+      m_JOY_CTRL.bits = Truncate16(value);
+      if (m_JOY_CTRL.RESET)
+        SoftReset();
+
+      if (m_JOY_CTRL.ACK)
+      {
+        // reset stat bits
+        m_JOY_STAT.ACKINPUTLEVEL = false;
+        m_JOY_STAT.INTR = false;
+        m_JOY_CTRL.ACK = true;
+      }
+
+      if (!old_select && m_JOY_CTRL.SELECT && !m_TX_FIFO.IsEmpty())
+        DoTransfer();
+
+      return;
+    }
+
+    case 0x08: // JOY_MODE
+    {
+      Log_DebugPrintf("JOY_MODE <- 0x%08X", value);
+      m_JOY_MODE.bits = Truncate16(value);
+      return;
+    }
+
+    case 0x0E:
+    {
+      Log_WarningPrintf("JOY_BAUD <- 0x%08X", value);
+      return;
+    }
+
+    default:
+      Log_ErrorPrintf("Unknown register write: 0x%X <- 0x%08X", offset, value);
+      return;
+  }
+}
+
+void Pad::SoftReset()
+{
+  m_JOY_CTRL.bits = 0;
+  m_JOY_STAT.bits = 0;
+  m_JOY_MODE.bits = 0;
+  m_RX_FIFO.Clear();
+  m_TX_FIFO.Clear();
+  UpdateJoyStat();
+}
+
+void Pad::UpdateJoyStat()
+{
+  m_JOY_STAT.RXFIFONEMPTY = !m_RX_FIFO.IsEmpty();
+  m_JOY_STAT.TXDONE = m_TX_FIFO.IsEmpty();
+  m_JOY_STAT.TXRDY = !m_TX_FIFO.IsFull();
+}
+
+void Pad::DoTransfer()
+{
+  Log_DebugPrintf("Transferring slot %d", m_JOY_CTRL.SLOT.GetValue());
+
+  const std::shared_ptr<PadDevice>& dev = m_devices[m_JOY_CTRL.SLOT];
+  if (!dev)
+  {
+    // no device present, don't set ACK and read hi-z
+    m_TX_FIFO.Clear();
+    m_RX_FIFO.Clear();
+    m_RX_FIFO.Push(0xFF);
+    UpdateJoyStat();
+    return;
+  }
+
+  while (!m_TX_FIFO.IsEmpty())
+  {
+    const u8 data_out = m_TX_FIFO.Pop();
+    u8 data_in;
+    m_JOY_STAT.ACKINPUTLEVEL |= dev->Transfer(data_out, &data_in);
+    m_RX_FIFO.Push(data_in);
+    m_JOY_CTRL.RXEN = true;
+  }
+
+  if (m_JOY_STAT.ACKINPUTLEVEL && m_JOY_CTRL.ACKINTEN)
+  {
+    m_JOY_STAT.INTR = true;
+    m_interrupt_controller->InterruptRequest(InterruptController::IRQ::IRQ7);
+  }
+
+  UpdateJoyStat();
+}