Diff: targets/TARGET_STM/lp_ticker.c

Revision:

181:57724642e740

Parent:

180:96ed750bd169

Child:

186:707f6e361f3e

--- a/targets/TARGET_STM/lp_ticker.c	Wed Jan 17 15:23:54 2018 +0000
+++ b/targets/TARGET_STM/lp_ticker.c	Fri Feb 16 16:09:33 2018 +0000
@@ -27,12 +27,264 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *******************************************************************************
  */
-#include "device.h"
 
 #if DEVICE_LOWPOWERTIMER
 
 #include "rtc_api_hal.h"
 
+#if MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM
+
+LPTIM_HandleTypeDef LptimHandle;
+
+volatile uint32_t lp_SlaveCounter = 0;
+volatile uint32_t lp_oc_int_part = 0;
+volatile uint16_t lp_TickPeriod_us;
+volatile uint8_t  lp_Fired = 0;
+
+static void LPTIM1_IRQHandler(void);
+static void (*irq_handler)(void);
+
+
+void lp_ticker_init(void)
+{
+    /* Check if LPTIM is already configured */
+#if (TARGET_STM32L0)
+    if (READ_BIT(RCC->APB1ENR, RCC_APB1ENR_LPTIM1EN) != RESET) {
+        return;
+    }
+#else
+    if (__HAL_RCC_LPTIM1_IS_CLK_ENABLED()) {
+        return;
+    }
+#endif
+
+    RCC_PeriphCLKInitTypeDef RCC_PeriphCLKInitStruct = {0};
+    RCC_OscInitTypeDef RCC_OscInitStruct = {0};
+
+#if MBED_CONF_TARGET_LSE_AVAILABLE
+
+    /* Enable LSE clock */
+    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE;
+    RCC_OscInitStruct.LSEState = RCC_LSE_ON;
+    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
+
+    /* Select the LSE clock as LPTIM peripheral clock */
+    RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
+#if (TARGET_STM32L0)
+    RCC_PeriphCLKInitStruct.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSE;
+#else
+    RCC_PeriphCLKInitStruct.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSE;
+#endif
+
+#else /* MBED_CONF_TARGET_LSE_AVAILABLE */
+
+    /* Enable LSI clock */
+    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
+    RCC_OscInitStruct.LSIState = RCC_LSI_ON;
+    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
+
+    /* Select the LSI clock as LPTIM peripheral clock */
+    RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
+#if (TARGET_STM32L0)
+    RCC_PeriphCLKInitStruct.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
+#else
+    RCC_PeriphCLKInitStruct.Lptim1ClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
+#endif
+
+#endif /* MBED_CONF_TARGET_LSE_AVAILABLE */
+
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        error("HAL_RCC_OscConfig ERROR\n");
+        return;
+    }
+
+    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct) != HAL_OK) {
+        error("HAL_RCCEx_PeriphCLKConfig ERROR\n");
+        return;
+    }
+
+    __HAL_RCC_LPTIM1_CLK_ENABLE();
+    __HAL_RCC_LPTIM1_FORCE_RESET();
+    __HAL_RCC_LPTIM1_RELEASE_RESET();
+
+    /* Initialize the LPTIM peripheral */
+    LptimHandle.Instance = LPTIM1;
+    LptimHandle.State = HAL_LPTIM_STATE_RESET;
+    LptimHandle.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
+
+    /*  Prescaler impact:
+            tick period = Prescaler division factor / LPTIM clock
+            Example with LPTIM clock = 32768 Hz LSE
+                Prescaler = LPTIM_PRESCALER_DIV1   => lp_TickPeriod_us = 31us  =>   2s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV2   => lp_TickPeriod_us = 61us  =>   4s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV4   => lp_TickPeriod_us = 122us =>   8s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV8   => lp_TickPeriod_us = 244us =>  16s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV16  => lp_TickPeriod_us = 488us =>  32s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV32  => lp_TickPeriod_us = 976us =>  64s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV64  => lp_TickPeriod_us = 1.9ms => 128s with 16b timer
+                Prescaler = LPTIM_PRESCALER_DIV128 => lp_TickPeriod_us = 3.9ms => 256s with 16b timer
+    */
+    LptimHandle.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV2;
+    lp_TickPeriod_us = 2 * 1000000 / RTC_CLOCK;
+
+    LptimHandle.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
+    LptimHandle.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
+    LptimHandle.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
+    LptimHandle.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
+#if (TARGET_STM32L4)
+    LptimHandle.Init.Input1Source = LPTIM_INPUT1SOURCE_GPIO;
+    LptimHandle.Init.Input2Source = LPTIM_INPUT2SOURCE_GPIO;
+#endif /* TARGET_STM32L4 */
+
+    if (HAL_LPTIM_Init(&LptimHandle) != HAL_OK) {
+        error("HAL_LPTIM_Init ERROR\n");
+        return;
+    }
+
+    NVIC_SetVector(LPTIM1_IRQn, (uint32_t)LPTIM1_IRQHandler);
+    NVIC_EnableIRQ(LPTIM1_IRQn);
+
+#if !(TARGET_STM32L4)
+    /* EXTI lines are not configured by default */
+    __HAL_LPTIM_WAKEUPTIMER_EXTI_ENABLE_IT();
+    __HAL_LPTIM_WAKEUPTIMER_EXTI_ENABLE_RISING_EDGE();
+#endif
+
+    __HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_ARRM);
+    __HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_CMPM);
+    __HAL_LPTIM_ENABLE_IT(&LptimHandle, LPTIM_IT_CMPOK);
+    HAL_LPTIM_Counter_Start(&LptimHandle, 0xFFFF);
+}
+
+static void LPTIM1_IRQHandler(void)
+{
+    LptimHandle.Instance = LPTIM1;
+
+    if (lp_Fired) {
+        lp_Fired = 0;
+        if (irq_handler) {
+            irq_handler();
+        }
+    }
+
+    /* Compare match interrupt */
+    if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPM) != RESET) {
+        if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_CMPM) != RESET) {
+            /* Clear Compare match flag */
+            __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
+
+            if (lp_oc_int_part > 0) {
+                lp_oc_int_part--;
+            } else {
+                if (irq_handler) {
+                    irq_handler();
+                }
+            }
+        }
+    }
+
+    /* Compare write interrupt */
+    if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK) != RESET) {
+        if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_CMPOK) != RESET) {
+            /* Clear Compare write flag */
+            __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK);
+        }
+    }
+
+    /* Autoreload match interrupt */
+    if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) != RESET) {
+        if (__HAL_LPTIM_GET_IT_SOURCE(&LptimHandle, LPTIM_IT_ARRM) != RESET) {
+            /* Clear Autoreload match flag */
+            __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_ARRM);
+            lp_SlaveCounter++;
+        }
+    }
+
+#if !(TARGET_STM32L4)
+    __HAL_LPTIM_WAKEUPTIMER_EXTI_CLEAR_FLAG();
+#endif
+}
+
+
+uint32_t lp_ticker_read_TickCounter(void)
+{
+    uint16_t cntH_old, cntH, cntL;
+
+    LptimHandle.Instance = LPTIM1;
+
+    /* same algo as us_ticker_read in us_ticker_16b.c */
+    do {
+        cntH_old = lp_SlaveCounter;
+        if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) == SET) {
+            cntH_old += 1;
+        }
+        cntL = LPTIM1->CNT;
+        cntH = lp_SlaveCounter;
+        if (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_ARRM) == SET) {
+            cntH += 1;
+        }
+    } while (cntH_old != cntH);
+    uint32_t lp_time = (uint32_t)(cntH << 16 | cntL);
+    return lp_time;
+}
+
+uint32_t lp_ticker_read(void)
+{
+    lp_ticker_init();
+    return lp_ticker_read_TickCounter() * (uint32_t)lp_TickPeriod_us;
+}
+
+void lp_ticker_set_interrupt(timestamp_t timestamp)
+{
+    // Disable IRQs
+    core_util_critical_section_enter();
+
+    uint32_t timestamp_TickCounter = timestamp / (uint32_t)lp_TickPeriod_us;
+
+    LptimHandle.Instance = LPTIM1;
+    irq_handler = (void (*)(void))lp_ticker_irq_handler;
+
+    __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK);
+    __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
+    __HAL_LPTIM_COMPARE_SET(&LptimHandle, timestamp_TickCounter & 0xFFFF);
+
+    /* CMPOK is set by hardware to inform application that the APB bus write operation to the LPTIM_CMP register has been successfully completed */
+    while (__HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPOK) == RESET) {
+    }
+
+    /* same algo as us_ticker_set_interrupt in us_ticker_16b.c */
+    uint32_t current_time_TickCounter = lp_ticker_read_TickCounter();
+    uint32_t delta = timestamp_TickCounter - current_time_TickCounter;
+    lp_oc_int_part = (delta - 1) >> 16;
+    if ( ((delta - 1) & 0xFFFF) >= 0x8000 &&
+            __HAL_LPTIM_GET_FLAG(&LptimHandle, LPTIM_FLAG_CMPM) == SET ) {
+        ++lp_oc_int_part;
+    }
+
+    // Enable IRQs
+    core_util_critical_section_exit();
+}
+
+void lp_ticker_fire_interrupt(void)
+{
+    lp_Fired = 1;
+    NVIC_SetPendingIRQ(LPTIM1_IRQn);
+}
+
+void lp_ticker_disable_interrupt(void)
+{
+    LptimHandle.Instance = LPTIM1;
+    __HAL_LPTIM_DISABLE_IT(&LptimHandle, LPTIM_IT_CMPM);
+}
+
+void lp_ticker_clear_interrupt(void)
+{
+    LptimHandle.Instance = LPTIM1;
+    __HAL_LPTIM_CLEAR_FLAG(&LptimHandle, LPTIM_FLAG_CMPM);
+}
+
+#else /* MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM */
+
 void lp_ticker_init(void)
 {
     rtc_init();
@@ -40,15 +292,8 @@
 
 uint32_t lp_ticker_read(void)
 {
-    uint32_t usecs = 0;
-    time_t time = 0;
-
-    do {
-        time = rtc_read();
-        usecs = rtc_read_subseconds();
-    } while (time != rtc_read());
-
-    return (time * 1000000) + usecs;
+    uint32_t usecs = rtc_read_us();
+    return usecs;
 }
 
 void lp_ticker_set_interrupt(timestamp_t timestamp)
@@ -74,4 +319,6 @@
     NVIC_ClearPendingIRQ(RTC_WKUP_IRQn);
 }
 
+#endif /* MBED_CONF_TARGET_LOWPOWERTIMER_LPTIM */
+
 #endif /* DEVICE_LOWPOWERTIMER */