Import Mbed OS hard-float snapshot

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/api/lp_ticker.c

@@ -0,0 +1,121 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2016 - 2018 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if DEVICE_LPTICKER
+
+#include "lp_ticker_api.h"
+#include "fsl_lptmr.h"
+#include "cmsis.h"
+
+const ticker_info_t* lp_ticker_get_info()
+{
+    static const ticker_info_t info = {
+        32768,        // 32kHz
+           16         // 16 bit counter
+    };
+    return &info;
+}
+
+#define OSC32K_CLK_HZ (32768)
+
+static bool lp_ticker_inited = false;
+
+static void lptmr_isr(void)
+{
+    LPTMR_ClearStatusFlags(LPTMR0, kLPTMR_TimerCompareFlag);
+    lp_ticker_irq_handler();
+}
+
+/** Initialize the low power ticker
+ *
+ */
+void lp_ticker_init(void)
+{
+    lptmr_config_t lptmrConfig;
+
+    if (!lp_ticker_inited) {
+        /* Setup high resolution clock - LPTMR */
+        LPTMR_GetDefaultConfig(&lptmrConfig);
+
+        /* Use 32kHz drive */
+        CLOCK_SetXtal32Freq(OSC32K_CLK_HZ);
+
+        lptmrConfig.prescalerClockSource = kLPTMR_PrescalerClock_2;
+        lptmrConfig.enableFreeRunning = true;
+        LPTMR_Init(LPTMR0, &lptmrConfig);
+        LPTMR_DisableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
+        NVIC_ClearPendingIRQ(LPTMR0_IRQn);
+        NVIC_SetVector(LPTMR0_IRQn, (uint32_t)lptmr_isr);
+        EnableIRQ(LPTMR0_IRQn);
+
+        lp_ticker_inited = true;
+    } else {
+        lp_ticker_disable_interrupt();
+    }
+}
+
+/** Read the current counter
+ *
+ * @return The current timer's counter value in ticks
+ */
+uint32_t lp_ticker_read(void)
+{
+    return LPTMR_GetCurrentTimerCount(LPTMR0);
+}
+
+/** Set interrupt for specified timestamp
+ *
+ * @param timestamp The time in ticks to be set
+ */
+void lp_ticker_set_interrupt(timestamp_t timestamp)
+{
+    if (timestamp == 0) {
+        timestamp = 1;
+    }
+    LPTMR_SetTimerPeriod(LPTMR0, timestamp);
+    LPTMR_ClearStatusFlags(LPTMR0, kLPTMR_TimerCompareFlag);
+    LPTMR_EnableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
+    LPTMR_StartTimer(LPTMR0);
+}
+
+void lp_ticker_fire_interrupt(void)
+{
+    NVIC_SetPendingIRQ(LPTMR0_IRQn);
+}
+
+/** Disable low power ticker interrupt
+ *
+ */
+void lp_ticker_disable_interrupt(void)
+{
+    LPTMR_DisableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
+}
+
+/** Clear the low power ticker interrupt
+ *
+ */
+void lp_ticker_clear_interrupt(void)
+{
+    LPTMR_ClearStatusFlags(LPTMR0, kLPTMR_TimerCompareFlag);
+}
+
+void lp_ticker_free(void)
+{
+    LPTMR_DisableInterrupts(LPTMR0, kLPTMR_TimerInterruptEnable);
+    NVIC_DisableIRQ(LPTMR0_IRQn);
+}
+
+#endif /* DEVICE_LPTICKER */