Mouse code for the MacroRat
mbed-dev/targets/TARGET_ARM_SSG/TARGET_BEETLE/lp_ticker.c
- Committer:
- sahilmgandhi
- Date:
- 2017-05-14
- Revision:
- 18:6a4db94011d3
File content as of revision 18:6a4db94011d3:
/* * PackageLicenseDeclared: Apache-2.0 * 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 "cmsis.h" #include "device.h" #include "objects.h" #include "lp_ticker_api.h" /* Private lp_ticker data */ /* lp_ticker initialize */ static uint32_t lp_ticker_initialized = 0; /* lp_ticker reload value */ static uint32_t lp_ticker_reload = 0x0; /* Max Value */ /* Store Overflow Delta */ static uint32_t lp_ticker_overflows_delta = 0; /* lp_ticker Overflow limit */ static uint32_t lp_ticker_overflow_limit = 0; #if DEVICE_LOWPOWERTIMER /** * Interrupt Handler */ void __lp_ticker_irq_handler(void) { if (DualTimer_GetIRQInfo(DUALTIMER0) == SINGLETIMER2) { DualTimer_ClearInterrupt(DUALTIMER0); /* * For each overflow event adds the timer max represented value to * the delta. This allows the lp_ticker to keep track of the elapsed * time: * elapsed_time = (num_overflow * overflow_limit) + current_time */ lp_ticker_overflows_delta += lp_ticker_overflow_limit; } else { lp_ticker_irq_handler(); } } /** * Initialize the low power ticker */ void lp_ticker_init(void) { uint32_t lp_ticker_irqn = 0; /* Verify if lp_ticker has been already Initialized */ if (lp_ticker_initialized == 1) { return; } lp_ticker_initialized = 1; /* Dualtimer Initialize */ DualTimer_Initialize(DUALTIMER0, lp_ticker_reload); /* Dualtimer Enable */ DualTimer_Enable(DUALTIMER0, DUALTIMER_COUNT_32 //| DUALTIMER_PERIODIC ); /* DualTimer get IRQn */ lp_ticker_irqn = DualTimer_GetIRQn(DUALTIMER0); /* Enable lp_ticker IRQ */ NVIC_SetVector((IRQn_Type)lp_ticker_irqn, (uint32_t)__lp_ticker_irq_handler); NVIC_EnableIRQ((IRQn_Type)lp_ticker_irqn); /* DualTimer set interrupt on SINGLETIMER2 */ DualTimer_SetInterrupt_2(DUALTIMER0, DUALTIMER_DEFAULT_RELOAD, DUALTIMER_COUNT_32 | DUALTIMER_PERIODIC); /* * Set lp_ticker Overflow limit. The lp_ticker overflow limit is required * to calculated the return value of the lp_ticker read function in us * on 32bit. * A 32bit us value cannot be represented directly in the Dual Timer Load * register if it is greater than (0xFFFFFFFF ticks)/DUALTIMER_DIVIDER_US. */ lp_ticker_overflow_limit = DualTimer_GetReloadValue(DUALTIMER0, SINGLETIMER2); } /** * Read the current counter * @return: The current timer's counter value in microseconds */ uint32_t lp_ticker_read(void) { uint32_t microseconds = 0; /* Verify if lp_ticker has not been Initialized */ if (lp_ticker_initialized == 0) lp_ticker_init(); /* Read Timer Value */ microseconds = lp_ticker_overflows_delta + DualTimer_Read_2(DUALTIMER0); return microseconds; } /** * Set interrupt for specified timestamp * timestamp: The time in microseconds to be set */ void lp_ticker_set_interrupt(timestamp_t timestamp) { int32_t delta = 0; /* Verify if lp_ticker has been not Initialized */ if (lp_ticker_initialized == 0) lp_ticker_init(); /* Calculate the delta */ delta = (int32_t)(timestamp - lp_ticker_read()); /* Check if the event was in the past */ if (delta <= 0) { /* This event was in the past */ DualTimer_SetInterrupt_1(DUALTIMER0, 0, DUALTIMER_COUNT_32 | DUALTIMER_ONESHOT); return; } /* Enable interrupt on SingleTimer1 */ DualTimer_SetInterrupt_1(DUALTIMER0, delta, DUALTIMER_COUNT_32 | DUALTIMER_ONESHOT); } /** * Disable low power ticker interrupt */ void lp_ticker_disable_interrupt(void) { /* Disable Interrupt */ DualTimer_DisableInterrupt(DUALTIMER0, SINGLETIMER1); } /** * Clear the low power ticker interrupt */ void lp_ticker_clear_interrupt(void) { /* Clear Interrupt */ DualTimer_ClearInterrupt(DUALTIMER0); } #endif