Merge branch 'wip-family-support'

Merge the long-lived (too long; future changes like these will need to
proceed more incrementally) development branch of libmaple, containing
experimental STM32F2 and STM32F1 value line support, into master.

This required many changes to the structure of the library. The most
important structural reorganizations occurred in:

- 954f9e5: moves public headers to include directories
- 3efa313: uses "series" instead of "family"
- c0d60e3: adds board files to the build system, to make it easier to
  add new boards
- 096d86c: adds build logic for targeting different STM32 series
  (e.g. STM32F1, STM32F2)

This last commit in particular (096d86c) is the basis for the
repartitioning of libmaple into portable sections, which work on all
supported MCUs, and nonportable sections, which are segregated into
separate directories and contain all series-specific code. Moving
existing STM32F1-only code into libmaple/stm32f1 and wirish/stm32f1,
along with adding equivalents under .../stm32f2 directories, was the
principal project of this branch.

Important API changes occur in several places. Existing code is still
expected to work on STM32F1 targets, but there have been many
deprecations. A detailed changelog explaining the situation needs to
be prepared.

F2 and F1 value line support is not complete; the merge is proceeding
prematurely in this respect. We've been getting more libmaple patches
from the community lately, and I'm worried that the merge conflicts
with the old tree structure will become painful to manage.

Conflicts:
	Makefile

Resolved Makefile conflicts manually; this required propagating
-Xlinker usage into support/make/target-config.mk.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

1 files changed, 37 insertions, 28 deletions

diff --git a/wirish/HardwareTimer.cpp b/wirish/HardwareTimer.cpp
index bd61a89..4f68ad7 100644
--- a/wirish/HardwareTimer.cpp
+++ b/wirish/HardwareTimer.cpp
@@ -24,39 +24,47 @@
  * SOFTWARE.
  *****************************************************************************/
 
-#include "HardwareTimer.h"
-#include "boards.h"             // for CYCLES_PER_MICROSECOND
-#include "wirish_math.h"
+#include <wirish/HardwareTimer.h>
+
+#include <libmaple/rcc.h>
+#include <wirish/ext_interrupts.h> // for noInterrupts(), interrupts()
+#include <wirish/wirish_math.h>
+#include <board/board.h>           // for CYCLES_PER_MICROSECOND
 
 // TODO [0.1.0] Remove deprecated pieces
 
-#ifdef STM32_MEDIUM_DENSITY
-#define NR_TIMERS 4
-#elif defined(STM32_HIGH_DENSITY)
-#define NR_TIMERS 8
-#else
-#error "Unsupported density"
-#endif
+/*
+ * Evil hack to infer this->dev from timerNum in the HardwareTimer
+ * constructor. See:
+ *
+ * http://www.parashift.com/c++-faq-lite/pointers-to-members.html#faq-33.2
+ * http://yosefk.com/c++fqa/function.html#fqa-33.2
+ */
+
+extern "C" {
+    static timer_dev **this_devp;
+    static rcc_clk_id this_id;
+    static void set_this_dev(timer_dev *dev) {
+        if (dev->clk_id == this_id) {
+            *this_devp = dev;
+        }
+    }
+}
 
-#define MAX_RELOAD ((1 << 16) - 1)
+/*
+ * HardwareTimer routines
+ */
 
 HardwareTimer::HardwareTimer(uint8 timerNum) {
-    if (timerNum > NR_TIMERS) {
-        ASSERT(0);
-    }
-    timer_dev *devs[] = {
-        TIMER1,
-        TIMER2,
-        TIMER3,
-        TIMER4,
-#ifdef STM32_HIGH_DENSITY
-        TIMER5,
-        TIMER6,
-        TIMER7,
-        TIMER8,
-#endif
-    };
-    this->dev = devs[timerNum - 1];
+    rcc_clk_id timerID = (rcc_clk_id)(RCC_TIMER1 + (timerNum - 1));
+    this->dev = NULL;
+    noInterrupts(); // Hack to ensure we're the only ones using
+                    // set_this_dev() and friends. TODO: use a lock.
+    this_id = timerID;
+    this_devp = &this->dev;
+    timer_foreach(set_this_dev);
+    interrupts();
+    ASSERT(this->dev != NULL);
 }
 
 void HardwareTimer::pause(void) {
@@ -92,6 +100,7 @@ void HardwareTimer::setCount(uint16 val) {
     timer_set_count(this->dev, min(val, ovf));
 }
 
+#define MAX_RELOAD ((1 << 16) - 1)
 uint16 HardwareTimer::setPeriod(uint32 microseconds) {
     // Not the best way to handle this edge case?
     if (!microseconds) {
@@ -102,7 +111,7 @@ uint16 HardwareTimer::setPeriod(uint32 microseconds) {
 
     uint32 period_cyc = microseconds * CYCLES_PER_MICROSECOND;
     uint16 prescaler = (uint16)(period_cyc / MAX_RELOAD + 1);
-    uint16 overflow = (uint16)round(period_cyc / prescaler);
+    uint16 overflow = (uint16)((period_cyc + (prescaler / 2)) / prescaler);
     this->setPrescaleFactor(prescaler);
     this->setOverflow(overflow);
     return overflow;