us ticker: fix fire interrupt handling

Few targets need more than just pending IRQ set. They include some flags to be
set that are checked in IRQ handler. This is the case for targets in this
commit.

Author: 0xc0170

targets/TARGET_ARM_SSG/TARGET_BEETLE/us_ticker.c

@@ -100,7 +100,7 @@ void us_ticker_set_interrupt(timestamp_t timestamp) {
 
 void us_ticker_fire_interrupt(void)
 {
-    uint32_t us_ticker_irqn1 = Timer_GetIRQn(TIMER1);
+    uint32_t us_ticker_irqn1 = Timer_GetIRQn(TIMER0);
     NVIC_SetPendingIRQ((IRQn_Type)us_ticker_irqn1);
 }
 

targets/TARGET_Freescale/TARGET_KLXX/us_ticker.c

@@ -199,6 +199,9 @@ void us_ticker_set_interrupt(timestamp_t timestamp) {
 
 void us_ticker_fire_interrupt(void)
 {
+    us_ticker_int_counter = 0;
+    us_ticker_int_remainder = 0;
+
 #if defined(TARGET_KL43Z)
     NVIC_SetPendingIRQ(LPTMR0_IRQn);
 #else

targets/TARGET_Maxim/TARGET_MAX32600/us_ticker.c

@@ -236,7 +236,9 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
-    NVIC_SetPendingIRQ(US_TIMER_IRQn);
+    US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0;  // disable timer
+    US_TIMER->term_cnt32 = 1;    
+    US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0;   // enable timer
 }
 
 //******************************************************************************

targets/TARGET_Maxim/TARGET_MAX32610/us_ticker.c

@@ -236,7 +236,9 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
-    NVIC_SetPendingIRQ(US_TIMER_IRQn);
+    US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0;  // disable timer
+    US_TIMER->term_cnt32 = 1;
+    US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0;   // enable timer
 }
 
 //******************************************************************************

targets/TARGET_Maxim/TARGET_MAX32620/us_ticker.c

@@ -267,7 +267,9 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
-    NVIC_SetPendingIRQ(US_TIMER_IRQn);
+    US_TIMER->ctrl &= ~MXC_F_TMR_CTRL_ENABLE0;  // disable timer
+    US_TIMER->term_cnt32 = 1;
+    US_TIMER->ctrl |= MXC_F_TMR_CTRL_ENABLE0;   // enable timer
 }
 
 //******************************************************************************

targets/TARGET_Maxim/TARGET_MAX32625/us_ticker.c

@@ -230,7 +230,7 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
-    NVIC_SetPendingIRQ(US_TIMER_IRQn);
+    TMR32_SetCompare(US_TIMER, 1);
 }
 
 //******************************************************************************

targets/TARGET_Maxim/TARGET_MAX32630/us_ticker.c

@@ -230,7 +230,7 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
-    NVIC_SetPendingIRQ(US_TIMER_IRQn);
+    TMR32_SetCompare(US_TIMER, 1);
 }
 
 //******************************************************************************

targets/TARGET_NORDIC/TARGET_MCU_NRF51822/us_ticker.c

@@ -20,6 +20,7 @@
 #include "PeripheralNames.h"
 #include "nrf_delay.h"
 #include "mbed_toolchain.h"
+#include "mbed_critical.h"
 
 /*
  * Note: The micro-second timer API on the nRF51 platform is implemented using
@@ -52,6 +53,8 @@
 #define RTC_UNITS_TO_MICROSECONDS(RTC_UNITS) (((RTC_UNITS) * (uint64_t)1000000) / RTC_CLOCK_FREQ)
 #define MICROSECONDS_TO_RTC_UNITS(MICROS)    ((((uint64_t)(MICROS) * RTC_CLOCK_FREQ) + 999999) / 1000000)
 
+#define US_TICKER_SW_IRQ_MASK 0x1
+
 static bool              us_ticker_inited = false;
 static volatile uint32_t overflowCount;                   /**< The number of times the 24-bit RTC counter has overflowed. */
 static volatile bool     us_ticker_callbackPending = false;
@@ -62,6 +65,9 @@ static bool              os_tick_started = false;         /**< flag indicating i
  */
 static uint32_t          previous_tick_cc_value = 0;
 
+// us ticker fire interrupt flag for IRQ handler
+volatile uint8_t m_common_sw_irq_flag = 0; 
+
 /*
  RTX provide the following definitions which are used by the tick code:
    * os_trv: The number (minus 1) of clock cycle between two tick.
@@ -181,6 +187,11 @@ static inline uint32_t rtc1_getCounter(void)
  */
 void us_ticker_handler(void)
 {
+    if (m_common_sw_irq_flag & US_TICKER_SW_IRQ_MASK) {
+        m_common_sw_irq_flag &= ~US_TICKER_SW_IRQ_MASK;
+        us_ticker_irq_handler();
+    }
+
     if (NRF_RTC1->EVENTS_OVRFLW) {
         overflowCount++;
         NRF_RTC1->EVENTS_OVRFLW = 0;
@@ -287,7 +298,10 @@ void us_ticker_set_interrupt(timestamp_t timestamp)
 
 void us_ticker_fire_interrupt(void)
 {
+    core_util_critical_section_enter();
+    m_common_sw_irq_flag |= US_TICKER_SW_IRQ_MASK;
     NVIC_SetPendingIRQ(RTC1_IRQn);
+    core_util_critical_section_exit();
 }
 
 void us_ticker_disable_interrupt(void)

targets/TARGET_NORDIC/TARGET_NRF5/common_rtc.h

@@ -33,6 +33,9 @@
 #define OS_TICK_CC_CHANNEL      1
 #define LP_TICKER_CC_CHANNEL    2
 
+#define US_TICKER_SW_IRQ_MASK 0x1
+#define LP_TICKER_SW_IRQ_MASK 0x2
+
 #define COMMON_RTC_EVENT_COMPARE(channel) \
     CONCAT_2(NRF_RTC_EVENT_COMPARE_, channel)
 #define COMMON_RTC_INT_COMPARE_MASK(channel) \
@@ -47,6 +50,7 @@
 
 extern bool              m_common_rtc_enabled;
 extern uint32_t volatile m_common_rtc_overflows;
+extern uint8_t volatile m_common_sw_irq_flag; 
 
 void     common_rtc_init(void);
 uint32_t common_rtc_32bit_ticks_get(void);

targets/TARGET_NORDIC/TARGET_NRF5/lp_ticker.c

@@ -18,6 +18,7 @@
 #if DEVICE_LOWPOWERTIMER
 
 #include "common_rtc.h"
+#include "mbed_critical.h"
 
 void lp_ticker_init(void)
 {
@@ -37,10 +38,10 @@ void lp_ticker_set_interrupt(timestamp_t timestamp)
 
 void lp_ticker_fire_interrupt(void)
 {
-    uint32_t closest_safe_compare = common_rtc_32bit_ticks_get() + 2;
-
-    nrf_rtc_cc_set(COMMON_RTC_INSTANCE, LP_TICKER_CC_CHANNEL, RTC_WRAP(closest_safe_compare));
-    nrf_rtc_event_enable(COMMON_RTC_INSTANCE, LP_TICKER_INT_MASK);
+    core_util_critical_section_enter();
+    m_common_sw_irq_flag |= LP_TICKER_SW_IRQ_MASK;
+    NVIC_SetPendingIRQ(RTC1_IRQn);
+    core_util_critical_section_exit();
 }
 
 void lp_ticker_disable_interrupt(void)