Diff: targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/lp_ticker.c

Revision:

184:08ed48f1de7f

Child:

186:707f6e361f3e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_ARM_SSG/TARGET_CM3DS_MPS2/lp_ticker.c	Thu Apr 19 17:12:19 2018 +0100
@@ -0,0 +1,113 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 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.
+ */
+
+ /**
+  * Low-power elapsed time measure and interval timer in micro-secundum,
+  * servicing \ref lp_ticker_api.h, using CMSDK Timer1 \ref CMSDK_TIMER1_DEV.
+  */
+
+#include <limits.h>
+
+#include "cmsdk_ticker.h"
+#include "lp_ticker_api.h"
+#include "platform_devices.h"
+
+/**
+ * \brief Calculate clocks to us
+ *
+ * \param[in] tick Number of clock ticks
+ *
+ * \return Number of usec, relative to the timer frequency,
+ *         that a given ammount of ticks equates to.
+ */
+ static uint32_t convert_tick_to_us(uint32_t tick)
+ {
+     return (tick / (SystemCoreClock / SEC_TO_USEC_MULTIPLIER));
+ }
+
+/**
+ * \brief Calculate us to clock ticks
+ *
+ * \param[in] us Time to convert to clock ticks
+ *
+ * \return Number of clock ticks relative to the timer frequency,
+ *         that a given period of usec equates to.
+ */
+ static uint32_t convert_us_to_tick(uint32_t us)
+ {
+     return (us * (SystemCoreClock / SEC_TO_USEC_MULTIPLIER));
+ }
+
+static const struct tick_cfg_t cfg =
+{
+    .timer_driver = &CMSDK_TIMER1_DEV,
+    .irq_n = TIMER1_IRQn,
+    .interval_callback = &lp_ticker_irq_handler,
+    .convert_tick_to_time = &convert_tick_to_us,
+    .convert_time_to_tick = &convert_us_to_tick
+};
+
+static struct tick_data_t data =
+{
+    .is_initialized = false,
+    .cumulated_time = 0,
+    .max_interval_time = 0,
+    .reload_time = 0,
+    .interval_callback_enabled = false,
+    .previous_cumulated_time = 0,
+    .previous_elapsed = 0
+};
+
+static struct tick_drv_data_t timer_data =
+{
+    .cfg = &cfg,
+    .data = &data
+};
+
+void lp_ticker_init(void)
+{
+    cmsdk_ticker_init(&timer_data);
+}
+
+uint32_t lp_ticker_read()
+{
+    return cmsdk_ticker_read(&timer_data);
+}
+
+void lp_ticker_set_interrupt(timestamp_t timestamp)
+{
+    cmsdk_ticker_set_interrupt(&timer_data, timestamp);
+}
+
+void lp_ticker_disable_interrupt(void)
+{
+    cmsdk_ticker_disable_interrupt(&timer_data);
+}
+
+void lp_ticker_clear_interrupt(void)
+{
+    cmsdk_ticker_clear_interrupt(&timer_data);
+}
+
+void lp_ticker_fire_interrupt(void)
+{
+    cmsdk_ticker_fire_interrupt(&timer_data);
+}
+
+void TIMER1_IRQHandler(void)
+{
+    cmsdk_ticker_irq_handler(&timer_data);
+}