Mouse code for the MacroRat
mbed-dev/targets/TARGET_ARM_SSG/TARGET_BEETLE/us_ticker.c
- Committer:
- sahilmgandhi
- Date:
- 2017-05-14
- Revision:
- 18:6a4db94011d3
File content as of revision 18:6a4db94011d3:
/* 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 <stddef.h> #include "cmsis.h" #include "us_ticker_api.h" #include "PeripheralNames.h" /* Private data */ /* us_ticker reload value */ static uint32_t us_ticker_reload = 0x0; /* Max Value */ /* us ticker initialized */ static uint32_t us_ticker_inited = 0; /* us ticker overflow */ static uint32_t us_ticker_overflow_delta = 0; /* us ticker overflow limit */ static uint32_t us_ticker_overflow_limit = 0; void __us_ticker_irq_handler(void) { Timer_ClearInterrupt(TIMER1); /* * For each overflow event adds the timer max represented value to * the delta. This allows the us_ticker to keep track of the elapsed * time: * elapsed_time = (num_overflow * overflow_limit) + current_time */ us_ticker_overflow_delta += us_ticker_overflow_limit; } void us_ticker_init(void) { uint32_t us_ticker_irqn0 = 0; uint32_t us_ticker_irqn1 = 0; if (us_ticker_inited) return; us_ticker_inited = 1; /* Initialize Timer 0 */ Timer_Initialize(TIMER0, us_ticker_reload); /* Enable Timer 0 */ Timer_Enable(TIMER0); /* Initialize Timer 1 */ Timer_Initialize(TIMER1, us_ticker_reload); /* Enable Timer 1 */ Timer_Enable(TIMER1); /* Timer 0 get IRQn */ us_ticker_irqn0 = Timer_GetIRQn(TIMER0); NVIC_SetVector((IRQn_Type)us_ticker_irqn0, (uint32_t)us_ticker_irq_handler); NVIC_EnableIRQ((IRQn_Type)us_ticker_irqn0); /* Timer 1 get IRQn */ us_ticker_irqn1 = Timer_GetIRQn(TIMER1); NVIC_SetVector((IRQn_Type)us_ticker_irqn1, (uint32_t)__us_ticker_irq_handler); NVIC_EnableIRQ((IRQn_Type)us_ticker_irqn1); /* Timer set interrupt on TIMER1 */ Timer_SetInterrupt(TIMER1, TIMER_DEFAULT_RELOAD); /* * Set us_ticker Overflow limit. The us_ticker overflow limit is required * to calculated the return value of the us_ticker read function in us * on 32bit. * A 32bit us value cannot be represented directly in the Timer Load * register if it is greater than (0xFFFFFFFF ticks)/TIMER_DIVIDER_US. */ us_ticker_overflow_limit = Timer_GetReloadValue(TIMER1); } uint32_t us_ticker_read() { uint32_t return_value = 0; if (!us_ticker_inited) us_ticker_init(); return_value = us_ticker_overflow_delta + Timer_Read(TIMER1); return return_value; } void us_ticker_set_interrupt(timestamp_t timestamp) { int32_t delta = 0; if (!us_ticker_inited) us_ticker_init(); delta = (int32_t)(timestamp - us_ticker_read()); /* Check if the event was in the past */ if (delta <= 0) { /* This event was in the past */ Timer_SetInterrupt(TIMER0, 0); return; } /* If the event was not in the past enable interrupt */ Timer_SetInterrupt(TIMER0, delta); } void us_ticker_disable_interrupt(void) { Timer_DisableInterrupt(TIMER0); } void us_ticker_clear_interrupt(void) { Timer_ClearInterrupt(TIMER0); }