/* * File : board.c * This file is part of RT-Thread RTOS * COPYRIGHT (C) 2012, RT-Thread Development Team * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.rt-thread.org/license/LICENSE * * Change Logs: * Date Author Notes * 2012-11-20 Bernard the first version */ #include #include #include "board.h" #include #include #include #include #include static void rt_hw_timer_isr(int vector, void *param) { rt_tick_increase(); epit_get_compare_event(HW_EPIT1); } int rt_hw_timer_init(void) { uint32_t freq; // The ARM private peripheral clock is half the CPU clock. uint32_t periphClock = get_main_clock(CPU_CLK) / 2; uint32_t prescaler = (periphClock / 1000000) - 1; // Divide down the prescaler until it fits into 8 bits. We add up the number of ticks // it takes to equal a microsecond interval. while (prescaler > 0xff) { prescaler /= 2; } // Make sure the timer is off. HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 0; // Clear counter. HW_ARMGLOBALTIMER_COUNTERn_WR(0, 0); HW_ARMGLOBALTIMER_COUNTERn_WR(1, 0); // Set prescaler and clear other flags. HW_ARMGLOBALTIMER_CONTROL_WR(BF_ARMGLOBALTIMER_CONTROL_PRESCALER(prescaler)); // Now turn on the timer. HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 1; freq = get_main_clock(IPG_CLK); epit_init(HW_EPIT1, CLKSRC_IPG_CLK, freq / 1000000, SET_AND_FORGET, 10000, WAIT_MODE_EN | STOP_MODE_EN); epit_counter_enable(HW_EPIT1, 10000, IRQ_MODE); rt_hw_interrupt_install(IMX_INT_EPIT1, rt_hw_timer_isr, RT_NULL, "tick"); rt_hw_interrupt_umask(IMX_INT_EPIT1); return 0; } INIT_BOARD_EXPORT(rt_hw_timer_init); /** * This function will initialize beaglebone board */ void rt_hw_board_init(void) { enable_neon_fpu(); disable_strict_align_check(); rt_components_board_init(); rt_console_set_device(RT_CONSOLE_DEVICE_NAME); } /*@}*/