Use lp_ticker.c for NRF51 and NRF52 boards

targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/lp_ticker.c

@@ -1,75 +0,0 @@
-/* mbed Microcontroller Library
- * Copyright (c) 2015 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.
- */
-#include "lp_ticker_api.h"
-#include "common_rtc.h"
-#include "platform/mbed_critical.h"
-
-#if DEVICE_LPTICKER
-
-/* LP ticker is driven by 32kHz clock and counter length is 24 bits. */
-const ticker_info_t* lp_ticker_get_info()
-{
-    static const ticker_info_t info = {
-        RTC_FREQ,
-        RTC_COUNTER_BITS
-    };
-    return &info;
-}
-
-void lp_ticker_init(void)
-{
-    common_rtc_init();
-}
-
-void lp_ticker_free(void)
-{
-    // A common counter is used for RTC, lp_ticker and us_ticker, so it can't be
-    // disabled here, but this does not cause any extra cost.
-}
-
-uint32_t lp_ticker_read()
-{
-    return nrf_rtc_counter_get(COMMON_RTC_INSTANCE);
-}
-
-void lp_ticker_set_interrupt(timestamp_t timestamp)
-{
-    common_rtc_set_interrupt(timestamp,
-        LP_TICKER_CC_CHANNEL, LP_TICKER_INT_MASK);
-}
-
-void lp_ticker_fire_interrupt(void)
-{
-    core_util_critical_section_enter();
-
-    lp_ticker_interrupt_fire = true;
-
-    NVIC_SetPendingIRQ(RTC1_IRQn);
-
-    core_util_critical_section_exit();
-}
-
-void lp_ticker_disable_interrupt(void)
-{
-    nrf_rtc_int_disable(COMMON_RTC_INSTANCE, LP_TICKER_INT_MASK);
-}
-
-void lp_ticker_clear_interrupt(void)
-{
-    nrf_rtc_event_clear(COMMON_RTC_INSTANCE, LP_TICKER_EVENT);
-}
-
-#endif // DEVICE_LPTICKER