blob: 4c364a302fa3fbaca8d6c3013270331f2b526f60 [file] [log] [blame]
/*
* Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <arch_helpers.h>
#include <assert.h>
#include <bl_common.h>
#include <debug.h>
#include <delay_timer.h>
#include <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 % 10 == 0) && (div % 10 == 0)) {
mult /= 10;
div /= 10;
}
generic_delay_timer_init_args(mult, div);
}