Handout

device/ps2controller.cc

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+#include "ps2controller.h"
+
+#include "../arch/core_interrupt.h"
+#include "../arch/ioport.h"
+#include "../compiler/fix.h"
+#include "../debug/output.h"
+#include "keydecoder.h"
+
+namespace PS2Controller {
+
+// I/O Ports of the PS2 Controller
+static const IOPort ctrl_port(
+    0x64);  ///< Access status- (read) and command (write) register
+static const IOPort data_port(0x60);  ///< Access PS/2 device [keyboard] output-
+                                      ///< (read) and input (write) buffer
+/* The buffers are used to communicate with the controller or the connected
+ * PS/2 devices alike:
+ *  - For the output buffer, the controller decides to which PS/2 device the
+ *    data gets forwarded to -- by default it is the primary PS/2 device
+ * (keyboard).
+ *  - The source device from which the data was gathered can be determined using
+ *    the status flag (\ref IS_MOUSE).
+ *
+ * Please also note, that the naming of the buffer may be a bit contra-intuitive
+ * since it is the perspective of the PS/2 controller due to historical reasons.
+ */
+
+// Key decoder (stores the state of the modifier keys)
+static KeyDecoder key_decoder;
+
+// To store the current state of the Keyboard LEDs
+static uint8_t leds = 0;
+
+/*! \brief Flags in the PS/2 controller status register
+ */
+enum Status {
+  HAS_OUTPUT = 1 << 0,     ///< Output buffer non-empty?
+  INPUT_PENDING = 1 << 1,  ///< Is input buffer full?
+  SYSTEM_FLAG = 1 << 2,    ///< set on soft reset, cleared on power up
+  IS_COMMAND = 1 << 3,     ///< Is command Byte? (otherwise data)
+  IS_MOUSE = 1 << 5,       ///< Mouse output has data
+  TIMEOUT_ERROR = 1 << 6,  ///< Timeout error
+  PARITY_ERROR = 1 << 7    ///< Parity error
+};
+
+/*! \brief Commands to be send to the Keyboard
+ */
+enum KeyboardCommand : uint8_t {
+  KEYBOARD_SET_LED =
+      0xed,  ///< Set the LED (according to the following parameter byte)
+  KEYBOARD_SEND_ECHO = 0xee,    ///< Send an echo packet
+  KEYBOARD_SET_SPEED = 0xf3,    ///< Set the repeat rate (according to the
+                                ///< following parameter byte)
+  KEYBOARD_ENABLE = 0xf4,       ///< Enable Keyboard
+  KEYBOARD_DISABLE = 0xf5,      ///< Disable Keyboard
+  KEYBOARD_SET_DEFAULT = 0xf6,  ///< Load defaults
+};
+
+/*! \brief Replies
+ */
+enum Reply {
+  ACK = 0xfa,     ///< Acknowledgement
+  RESEND = 0xfe,  ///< Request to resend (not required to implement)
+  ECHO = 0xee     ///< Echo answer
+};
+
+/*! \brief Commands for the PS/2 Controller
+ *
+ * These commands are processed by the controller and *not* send to
+ * keyboard/mouse. They have to be written into the command register.
+ */
+enum ControllerCommand {
+  CONTROLLER_GET_COMMAND_BYTE = 0x20,  ///< Read Command Byte of PS/2 Controller
+  CONTROLLER_SET_COMMAND_BYTE =
+      0x60,                         ///< Write Command Byte of PS/2 Controller
+  CONTROLLER_MOUSE_DISABLE = 0xa7,  ///< Disable mouse interface
+  CONTROLLER_MOUSE_ENABLE = 0xa8,   ///< Enable mouse interface
+  CONTROLLER_KEYBOARD_DISABLE = 0xad,  ///< Disable keyboard interface
+  CONTROLLER_KEYBOARD_ENABLE = 0xae,   ///< Enable keyboard interface
+  CONTROLLER_SEND_TO_MOUSE = 0xd4,     ///< Send parameter to mouse device
+};
+
+/*! \brief Send a command or data to a connected PS/2 device
+ *
+ * The value must only be written into the input buffer after the previously
+ * written values have been fetched (\ref INPUT_PENDING in the status register).
+ *
+ *  \todo(11) Implement method
+ *
+ *  \param value data to be sent
+ */
+[[maybe_unused]] static void sendData(uint8_t value) {
+  // TODO: You have to implement this method
+  (void)value;
+}
+
+void init() {
+  // Switch all LEDs off (on many PCs NumLock is turned on after power up)
+  setLed(LED_CAPS_LOCK, false);
+  setLed(LED_SCROLL_LOCK, false);
+  setLed(LED_NUM_LOCK, false);
+
+  // Set to maximum speed & minimum delay
+  setRepeatRate(SPEED_30_0CPS, DELAY_250MS);
+}
+
+bool fetch(Key &pressed) {
+  // TODO: You have to implement this method
+  (void)pressed;
+  return false;
+}
+
+void setRepeatRate(Speed speed, Delay delay) {
+  (void)speed;
+  (void)delay;
+}
+
+void setLed(enum LED led, bool on) {
+  if (on) {
+    leds |= led;
+  } else {
+    leds &= ~led;
+  }
+  sendData(KEYBOARD_SET_LED);  // Command for the Keyboard
+  sendData(leds);              // Parameter
+}
+
+void drainBuffer() {}
+
+}  // namespace PS2Controller