From 377d2f7d7f04e067d022419363236960bc8a22f1 Mon Sep 17 00:00:00 2001
From: Pavel Kirienko <pavel.kirienko@gmail.com>
Date: Mon, 7 Apr 2014 15:17:58 +0400
Subject: [PATCH] STM32: iface activity indication

---
 .../stm32/driver/include/uavcan_stm32/can.hpp | 23 +++++++++++++++++++
 .../stm32/driver/src/uc_stm32_can.cpp         | 21 +++++++++++++++++
 .../stm32/test_stm32f107/src/main.cpp         |  9 ++++----
 3 files changed, 49 insertions(+), 4 deletions(-)

diff --git a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
index 1117cf8f1d..37bbb03b97 100644
--- a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
+++ b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
@@ -114,6 +114,7 @@ class CanIface : public uavcan::ICanIface, uavcan::Noncopyable
     TxItem pending_tx_[NumTxMailboxes];
     uavcan::uint8_t last_hw_error_code_;
     const uavcan::uint8_t self_index_;
+    bool had_activity_;
 
     int computeTimings(uavcan::uint32_t target_bitrate, Timings& out_timings);
 
@@ -141,11 +142,13 @@ public:
         , update_event_(update_event)
         , last_hw_error_code_(0)
         , self_index_(self_index)
+        , had_activity_(false)
     {
         assert(self_index_ < UAVCAN_STM32_NUM_IFACES);
     }
 
     /**
+     * Initializes the hardware CAN controller.
      * Assumes:
      *   - Iface clock is enabled
      *   - Iface has been resetted via RCC
@@ -163,8 +166,22 @@ public:
     bool isTxBufferFull() const;
     bool isRxBufferEmpty() const;
 
+    /**
+     * Total number of hardware failures.
+     * May increase continuously if the interface is not connected to the bus.
+     */
     virtual uavcan::uint64_t getErrorCount() const;
+
+    /**
+     * Returns last hardware error code (LEC field in the register ESR)
+     */
     uavcan::uint8_t yieldLastHardwareErrorCode();
+
+    /**
+     * Whether this iface had at least one successful IO since previous call of this method.
+     * This is designed for use with iface activity LEDs.
+     */
+    bool hadActivity();
 };
 
 /**
@@ -199,6 +216,12 @@ public:
     virtual CanIface* getIface(uavcan::uint8_t iface_index);
 
     virtual uavcan::uint8_t getNumIfaces() const { return UAVCAN_STM32_NUM_IFACES; }
+
+    /**
+     * Whether at least one iface had at least one successful IO since previous call of this method.
+     * This is designed for use with iface activity LEDs.
+     */
+    bool hadActivity();
 };
 
 /**
diff --git a/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp b/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
index 35f8c0e4e4..2b8351dacf 100644
--- a/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
+++ b/libuavcan_drivers/stm32/driver/src/uc_stm32_can.cpp
@@ -381,6 +381,9 @@ leave:
 void CanIface::handleTxMailboxInterrupt(uavcan::uint8_t mailbox_index, bool txok, const uavcan::uint64_t utc_usec)
 {
     assert(mailbox_index < NumTxMailboxes);
+
+    had_activity_ = had_activity_ || txok;
+
     TxItem& txi = pending_tx_[mailbox_index];
     if (txi.loopback && txok && txi.pending)
     {
@@ -471,6 +474,7 @@ void CanIface::handleRxInterrupt(uavcan::uint8_t fifo_index, uavcan::uint64_t ut
      */
     rx_queue_.push(frame, utc_usec, 0);
     update_event_.signalFromInterrupt();
+    had_activity_ = true;
 }
 
 void CanIface::handleStatusInterrupt()
@@ -522,6 +526,14 @@ uavcan::uint8_t CanIface::yieldLastHardwareErrorCode()
     return val;
 }
 
+bool CanIface::hadActivity()
+{
+    CriticalSectionLocker lock;
+    const bool ret = had_activity_;
+    had_activity_ = false;
+    return ret;
+}
+
 /*
  * CanDriver
  */
@@ -640,6 +652,15 @@ CanIface* CanDriver::getIface(uavcan::uint8_t iface_index)
     return NULL;
 }
 
+bool CanDriver::hadActivity()
+{
+    bool ret = if0_.hadActivity();
+#if UAVCAN_STM32_NUM_IFACES > 1
+    ret |= if1_.hadActivity();
+#endif
+    return ret;
+}
+
 } // namespace uavcan_stm32
 
 /*
diff --git a/libuavcan_drivers/stm32/test_stm32f107/src/main.cpp b/libuavcan_drivers/stm32/test_stm32f107/src/main.cpp
index 45def312f6..ae20071141 100644
--- a/libuavcan_drivers/stm32/test_stm32f107/src/main.cpp
+++ b/libuavcan_drivers/stm32/test_stm32f107/src/main.cpp
@@ -140,10 +140,11 @@ int main()
 
     while (true)
     {
-        app::ledSet(false);
-        sleep(1);
-        app::ledSet(true);
-        sleep(1);
+        for (int i = 0; i < 200; i++)
+        {
+            app::ledSet(app::can.driver.hadActivity());
+            ::usleep(25000);
+        }
 
         const uavcan::UtcTime utc = uavcan_stm32::clock::getUtc();
         lowsyslog("UTC %lu sec, %li corr, %lu jumps\n",