coreboot-kgpe-d16/payloads/libpayload/drivers/timer/img_pistachio.c
Ionela Voinescu 7d16196a8e pistachio: modify timer to account for CPU counter overflow
Extended the 32bit CPU counter to 64bit by adding a static
variable that takes into account CPU counter overflow.
The varibale is updated everythime the timer_raw_value
function is called so I assume that the function is called
often enought to not miss an overflow of the CPU counter.

BUG=chrome-os-partner:31438
TEST=tested on Pistachio bring up board; works as expected
BRANCH=none

Change-Id: I98bcc56e600dcff0c6da7c140dd34faec5e00885
Signed-off-by: Stefan Reinauer <reinauer@chromium.org>
Original-Commit-Id: 972b105f950d800fa44f27bce090f6b89a5a84b9
Original-Change-Id: Id67b14e9d9c2354bc417b6587b615d466690c9b7
Original-Signed-off-by: Ionela Voinescu <ionela.voinescu@imgtec.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/247642
Original-Reviewed-by: Daniel Ehrenberg <dehrenberg@chromium.org>
Reviewed-on: http://review.coreboot.org/9672
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
2015-04-14 12:08:39 +02:00

42 lines
1.3 KiB
C

/*
* This file is part of the libpayload project.
*
* Copyright (C) 2014 Imagination Technologies
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <libpayload.h>
#include <arch/cpu.h>
uint64_t timer_hz(void)
{
return lib_sysinfo.cpu_khz * 1000;
}
uint64_t timer_raw_value(void)
{
static uint64_t total_ticks = 0;
uint8_t overflow = 0;
uint32_t current_ticks = read_c0_count() * 2;
/* It assumes only one overflow happened since the last call */
if (current_ticks <= (uint32_t)total_ticks)
overflow = 1;
/* The least significant part(32 bits) of total_ticks will always
* become equal to current ticks */
total_ticks = (((total_ticks >> 32) + overflow) << 32) +
current_ticks;
return total_ticks;
}