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

60 lines
2.3 KiB
C

/*
*
* Copyright 2016 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.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* 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 <assert.h>
#include <libpayload.h>
uint64_t timer_hz(void)
{
/* libc/time.c currently requires all timers to be at least 1MHz. */
assert(CONFIG_LP_TIMER_GENERIC_HZ >= 1000000);
return CONFIG_LP_TIMER_GENERIC_HZ;
}
uint64_t timer_raw_value(void)
{
uint64_t cur_tick;
uint32_t count_h;
uint32_t count_l;
if (!CONFIG_LP_TIMER_GENERIC_HIGH_REG)
return readl(phys_to_virt(CONFIG_LP_TIMER_GENERIC_REG));
do {
count_h = readl(phys_to_virt(CONFIG_LP_TIMER_GENERIC_HIGH_REG));
count_l = readl(phys_to_virt(CONFIG_LP_TIMER_GENERIC_REG));
cur_tick = readl(phys_to_virt(CONFIG_LP_TIMER_GENERIC_HIGH_REG));
} while (cur_tick != count_h);
return (cur_tick << 32) + count_l;
}