Merge pull request #262 from victorpv/timer_dma

Timer dma from @victorpv

Author: rogerclarkmelbourne

STM32F1/system/libmaple/include/libmaple/timer.h

@@ -785,6 +785,22 @@ static inline void timer_dma_disable_trg_req(timer_dev *dev) {
     *bb_perip(&(dev->regs).gen->DIER, TIMER_DIER_TDE_BIT) = 0;
 }
 
+/**
+ * @brief Enable a timer's update DMA request
+ * @param dev Timer device, must have type TIMER_ADVANCED or TIMER_GENERAL
+ */
+static inline void timer_dma_enable_upd_req(timer_dev *dev) {
+    *bb_perip(&(dev->regs).gen->DIER, TIMER_DIER_UDE_BIT) = 1;
+}
+
+/**
+ * @brief Disable a timer's update DMA request
+ * @param dev Timer device, must have type TIMER_ADVANCED or TIMER_GENERAL
+ */
+static inline void timer_dma_disable_upd_req(timer_dev *dev) {
+    *bb_perip(&(dev->regs).gen->DIER, TIMER_DIER_UDE_BIT) = 0;
+}
+
 /**
  * @brief Enable a timer channel's DMA request.
  * @param dev Timer device, must have type TIMER_ADVANCED or TIMER_GENERAL