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/* * Copyright (c) 2017 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #include <kernel.h> #include <arch/cpu.h> #include <device.h> #include <drivers/timer/system_timer.h> #include <altera_common.h> #include "altera_avalon_timer_regs.h" #include "altera_avalon_timer.h" #include "legacy_api.h" static u32_t accumulated_cycle_count; static s32_t _sys_idle_elapsed_ticks = 1; static void timer_irq_handler(void *unused) { ARG_UNUSED(unused); #ifdef CONFIG_EXECUTION_BENCHMARKING extern void read_timer_start_of_tick_handler(void); read_timer_start_of_tick_handler(); #endif accumulated_cycle_count += k_ticks_to_cyc_floor32(1); /* Clear the interrupt */ alt_handle_irq((void *)TIMER_0_BASE, TIMER_0_IRQ); z_clock_announce(_sys_idle_elapsed_ticks); #ifdef CONFIG_EXECUTION_BENCHMARKING extern void read_timer_end_of_tick_handler(void); read_timer_end_of_tick_handler(); #endif } int z_clock_driver_init(struct device *device) { ARG_UNUSED(device); IOWR_ALTERA_AVALON_TIMER_PERIODL(TIMER_0_BASE, k_ticks_to_cyc_floor32(1) & 0xFFFF); IOWR_ALTERA_AVALON_TIMER_PERIODH(TIMER_0_BASE, (k_ticks_to_cyc_floor32(1) >> 16) & 0xFFFF); IRQ_CONNECT(TIMER_0_IRQ, 0, timer_irq_handler, NULL, 0); irq_enable(TIMER_0_IRQ); alt_avalon_timer_sc_init((void *)TIMER_0_BASE, 0, TIMER_0_IRQ, k_ticks_to_cyc_floor32(1)); return 0; } u32_t z_timer_cycle_get_32(void) { /* Per the Altera Embedded IP Peripherals guide, you cannot * use a timer instance for both the system clock and timestamps * at the same time. * * Having this function return accumulated_cycle_count + get_snapshot() * does not work reliably. It's possible for the current countdown * to reset to the next interval before the timer interrupt is * delivered (and accumulated cycle count gets updated). The result * is an unlucky call to this function will appear to jump backward * in time. * * To properly obtain timestamps, the CPU must be configured with * a second timer peripheral instance that is configured to * count down from some large initial 64-bit value. This * is currently unimplemented. */ return accumulated_cycle_count; } |