blob: 4b67ed0d148bec3b47ad91d44850a8514ef6d8d6 [file] [log] [blame]
/*
* Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <arch_helpers.h>
#include <common/bl_common.h>
#include <common/debug.h>
#include <drivers/delay_timer.h>
#include <drivers/generic_delay_timer.h>
#include <plat/common/platform.h>
/* Ticks elapsed in one second by a signal of 1 MHz */
#define MHZ_TICKS_PER_SEC 1000000
static timer_ops_t ops;
static uint32_t get_timer_value(void)
{
/*
* Generic delay timer implementation expects the timer to be a down
* counter. We apply bitwise NOT operator to the tick values returned
* by read_cntpct_el0() to simulate the down counter. The value is
* clipped from 64 to 32 bits.
*/
return (uint32_t)(~read_cntpct_el0());
}
void generic_delay_timer_init_args(uint32_t mult, uint32_t div)
{
ops.get_timer_value = get_timer_value;
ops.clk_mult = mult;
ops.clk_div = div;
timer_init(&ops);
VERBOSE("Generic delay timer configured with mult=%u and div=%u\n",
mult, div);
}
void generic_delay_timer_init(void)
{
/* Value in ticks */
unsigned int mult = MHZ_TICKS_PER_SEC;
/* Value in ticks per second (Hz) */
unsigned int div = plat_get_syscnt_freq2();
/* Reduce multiplier and divider by dividing them repeatedly by 10 */
while (((mult % 10U) == 0U) && ((div % 10U) == 0U)) {
mult /= 10U;
div /= 10U;
}
generic_delay_timer_init_args(mult, div);
}