From 22787651e699c58b18258a8cb01249b0f5f329cb Mon Sep 17 00:00:00 2001
From: Pavel Kirienko <pavel.kirienko@gmail.com>
Date: Mon, 1 Jun 2015 13:58:20 +0300
Subject: [PATCH] STM32 NuttX driver: Edge-triggered poll(), sort of fixes #35

---
 .../stm32/driver/include/uavcan_stm32/can.hpp |  3 +-
 .../driver/include/uavcan_stm32/thread.hpp    | 14 ++++-----
 .../stm32/driver/src/uc_stm32_thread.cpp      | 30 +++++--------------
 3 files changed, 14 insertions(+), 33 deletions(-)

diff --git a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
index 45e022bf38..170d69b820 100644
--- a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
+++ b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/can.hpp
@@ -194,8 +194,7 @@ class CanDriver : public uavcan::ICanDriver, uavcan::Noncopyable
 public:
     template <unsigned RxQueueCapacity>
     CanDriver(CanRxItem (&rx_queue_storage)[UAVCAN_STM32_NUM_IFACES][RxQueueCapacity])
-        : update_event_(*this)
-        , if0_(bxcan::Can[0], update_event_, 0, rx_queue_storage[0], RxQueueCapacity)
+        : if0_(bxcan::Can[0], update_event_, 0, rx_queue_storage[0], RxQueueCapacity)
 #if UAVCAN_STM32_NUM_IFACES > 1
         , if1_(bxcan::Can[1], update_event_, 1, rx_queue_storage[1], RxQueueCapacity)
 #endif
diff --git a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/thread.hpp b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/thread.hpp
index d2c6869ddc..5d084d6a94 100644
--- a/libuavcan_drivers/stm32/driver/include/uavcan_stm32/thread.hpp
+++ b/libuavcan_drivers/stm32/driver/include/uavcan_stm32/thread.hpp
@@ -34,11 +34,9 @@ class BusEvent
     chibios_rt::CounterSemaphore sem_;
 
 public:
-    BusEvent(CanDriver& can_driver)
+    BusEvent()
         : sem_(0)
-    {
-        (void)can_driver;
-    }
+    { }
 
     bool wait(uavcan::MonotonicDuration duration);
 
@@ -58,13 +56,15 @@ public:
 
 #elif UAVCAN_STM32_NUTTX
 
+/**
+ * All bus events are reported as POLLIN.
+ */
 class BusEvent : uavcan::Noncopyable
 {
     static const unsigned MaxPollWaiters = 8;
 
     ::file_operations file_ops_;
     ::pollfd* pollset_[MaxPollWaiters];
-    CanDriver& can_driver_;
     bool signal_;
 
     static int openTrampoline(::file* filp);
@@ -75,15 +75,13 @@ class BusEvent : uavcan::Noncopyable
     int close(::file* filp);
     int poll(::file* filp, ::pollfd* fds, bool setup);
 
-    unsigned makePollMask() const;
-
     int addPollWaiter(::pollfd* fds);
     int removePollWaiter(::pollfd* fds);
 
 public:
     static const char* const DevName;
 
-    BusEvent(CanDriver& can_driver);
+    BusEvent();
     ~BusEvent();
 
     bool wait(uavcan::MonotonicDuration duration);
diff --git a/libuavcan_drivers/stm32/driver/src/uc_stm32_thread.cpp b/libuavcan_drivers/stm32/driver/src/uc_stm32_thread.cpp
index c24885968d..4c7c16927e 100644
--- a/libuavcan_drivers/stm32/driver/src/uc_stm32_thread.cpp
+++ b/libuavcan_drivers/stm32/driver/src/uc_stm32_thread.cpp
@@ -99,7 +99,7 @@ int BusEvent::poll(::file* filp, ::pollfd* fds, bool setup)
         ret = addPollWaiter(fds);
         if (ret == 0)
         {
-            fds->revents |= fds->events & makePollMask();
+            fds->revents |= fds->events & POLLIN;
             if (fds->revents != 0)
             {
                 (void)sem_post(fds->sem);
@@ -114,26 +114,11 @@ int BusEvent::poll(::file* filp, ::pollfd* fds, bool setup)
     return ret;
 }
 
-unsigned BusEvent::makePollMask() const
-{
-    const uavcan::CanSelectMasks select_masks = can_driver_.makeSelectMasks();
-    unsigned poll_mask = 0;
-    if (select_masks.read != 0)
-    {
-        poll_mask |= POLLIN;
-    }
-    if (select_masks.write != 0)
-    {
-        poll_mask |= POLLOUT;
-    }
-    return poll_mask;
-}
-
 int BusEvent::addPollWaiter(::pollfd* fds)
 {
     for (unsigned i = 0; i < MaxPollWaiters; i++)
     {
-        if (pollset_[i] == nullptr)
+        if (pollset_[i] == NULL)
         {
             pollset_[i] = fds;
             return 0;
@@ -148,16 +133,15 @@ int BusEvent::removePollWaiter(::pollfd* fds)
     {
         if (fds == pollset_[i])
         {
-            pollset_[i] = nullptr;
+            pollset_[i] = NULL;
             return 0;
         }
     }
     return -EINVAL;
 }
 
-BusEvent::BusEvent(CanDriver& can_driver)
-    : can_driver_(can_driver)
-    , signal_(false)
+BusEvent::BusEvent()
+    : signal_(false)
 {
     std::memset(&file_ops_, 0, sizeof(file_ops_));
     std::memset(pollset_, 0, sizeof(pollset_));
@@ -201,9 +185,9 @@ void BusEvent::signalFromInterrupt()
     for (unsigned i = 0; i < MaxPollWaiters; i++)
     {
         ::pollfd* const fd = pollset_[i];
-        if (fd != nullptr)
+        if (fd != NULL)
         {
-            fd->revents = fd->events & makePollMask();
+            fd->revents |= fd->events & POLLIN;
             if ((fd->revents != 0) && (fd->sem->semcount <= 0))
             {
                 (void)sem_post(fd->sem);