coreboot-kgpe-d16/payloads/libpayload/drivers/timer/armada38x.c

51 lines
2.1 KiB
C

/*
* Copyright 2015 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <libpayload.h>
#include <libpayload-config.h>
uint64_t timer_hz(void)
{
return CONFIG_LP_ARMADA38X_TIMER_FREQ;
}
uint64_t timer_raw_value(void)
{
static uint64_t total_ticks = 0;
uint64_t overflow = 0;
uint32_t current_ticks =
0xffffffff - readl((void *)CONFIG_LP_ARMADA38X_TIMER_REG);
/* It assumes only one overflow happened since the last call */
if (current_ticks <= (uint32_t)total_ticks)
overflow = 1ULL << 32;
/* The least significant part(32 bits) of total_ticks will always
* become equal to current ticks */
total_ticks = (((total_ticks + overflow) >> 32) << 32) + current_ticks;
return total_ticks;
}