[ion] Add a method to know if the USB is plugged

Change-Id: I040ce7996bbec121c71d57a5092ffae4f5f76025

ion/include/ion.h

@@ -10,6 +10,7 @@
 #include <ion/keyboard.h>
 #include <ion/led.h>
 #include <ion/power.h>
+#include <ion/usb.h>
 #include <stdint.h>
 #include <string.h>
 

ion/include/ion/usb.h

@@ -0,0 +1,12 @@
+#ifndef ION_USB_H
+#define ION_USB_H
+
+namespace Ion {
+namespace USB {
+
+bool isPlugged();
+
+}
+}
+
+#endif

ion/src/device/Makefile

@@ -17,6 +17,7 @@ objs += $(addprefix ion/src/device/, \
   power.o\
   sd_card.o\
   swd.o \
+  usb.o \
 )
 
 # When using the register.h C++ file in production mode, we expect the compiler

ion/src/device/device.cpp

@@ -12,6 +12,7 @@ extern "C" {
 #include "backlight.h"
 #include "console.h"
 #include "swd.h"
+#include "usb.h"
 
 #define USE_SD_CARD 0
 
@@ -124,6 +125,7 @@ void initPeripherals() {
   Keyboard::Device::init();
   LED::Device::init();
   Battery::Device::init();
+  USB::Device::init();
 #if USE_SD_CARD
   SDCard::Device::init();
 #endif
@@ -137,6 +139,7 @@ void shutdownPeripherals() {
 #if USE_SD_CARD
   SDCard::Device::shutdown();
 #endif
+  USB::Device::shutdown();
   Battery::Device::shutdown();
   LED::Device::shutdown();
   Keyboard::Device::shutdown();

ion/src/device/usb.cpp

@@ -0,0 +1,34 @@
+#include <ion/usb.h>
+#include "usb.h"
+#include "regs/regs.h"
+
+namespace Ion {
+namespace USB {
+
+bool isPlugged() {
+  return Device::VbusPin.group().IDR()->get(Device::VbusPin.pin());
+}
+
+}
+}
+
+namespace Ion {
+namespace USB {
+namespace Device {
+
+void init() {
+  /* Configure the GPIO
+   * The VBUS pin is connected to the USB VBUS port. To read if the USB is
+   * plugged, the pin must be pulled down. */
+  VbusPin.group().MODER()->setMode(VbusPin.pin(), GPIO::MODER::Mode::Input);
+  VbusPin.group().PUPDR()->setPull(VbusPin.pin(), GPIO::PUPDR::Pull::Down);
+}
+
+void shutdown() {
+  VbusPin.group().MODER()->setMode(VbusPin.pin(), GPIO::MODER::Mode::Analog);
+  VbusPin.group().PUPDR()->setPull(VbusPin.pin(), GPIO::PUPDR::Pull::None);
+}
+
+}
+}
+}

ion/src/device/usb.h

@@ -0,0 +1,24 @@
+#ifndef ION_DEVICE_USB_H
+#define ION_DEVICE_USB_H
+
+#include "regs/regs.h"
+
+namespace Ion {
+namespace USB {
+namespace Device {
+
+/*  Pin | Role              | Mode                  | Function
+ * -----+-------------------+-----------------------+----------
+ *  PA9 | VBUS              | Input, pulled down    | Low = unplugged, high = plugged
+ */
+
+void init();
+void shutdown();
+
+constexpr static GPIOPin VbusPin = GPIOPin(GPIOA, 9);
+
+}
+}
+}
+
+#endif

ion/src/simulator/Makefile

@@ -2,6 +2,7 @@ objs += $(addprefix ion/src/simulator/, \
   battery.o\
   init.o\
   led.o\
+  usb.o\
 )
 
 objs += $(addprefix ion/src/simulator/boot/, main.o)

ion/src/simulator/usb.cpp

@@ -0,0 +1,6 @@
+#include <ion/usb.h>
+
+bool Ion::USB::isPlugged() {
+  return false;
+}
+