coreboot-kgpe-d16/payloads/libpayload/drivers/timer/ipq806x.c
Vadim Bendebury 11aaf1f42a ipq8064: Add work around for slow timer clock
Libpayload libc requires timer clock frequency to be at least 1MHz.
Ipq8064 code presently provides a single option of 32kHz. Pretend to
be running at 1 MHz without additional accuracy.

This is a hack which will be reverted as soon as the SOC is configured
to supply a faster running clock.

BUG=chrome-os-partner:27784, chrome-os-partner:28880
TEST=with other changes depthcharge boots to the CLI console

Original-Change-Id: I80ec6652bc5693a549668cd6e824e9cf5c26b182
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/201342
Original-Reviewed-by: David Hendricks <dhendrix@chromium.org>
(cherry picked from commit 466a59967b13986099106f8b44924648c1e6e6cd)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>

Change-Id: I113689191db70710e7a45ccd02d672f482343e35
Reviewed-on: http://review.coreboot.org/8004
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins)
2015-01-04 00:27:50 +01:00

59 lines
2.3 KiB
C

/*
* This file is part of the depthcharge project.
*
* Copyright (C) 2014 The Linux Foundation. All rights reserved.
*
* 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>
/*
* TODO(vbendeb): reverted this hack once proper timer code is in place (see
* http://crosbug.com/p/28880 for details.
*/
#define MIN_TIMER_FREQ 1000000
uint64_t timer_hz(void)
{
return (CONFIG_LP_IPQ806X_TIMER_FREQ >= MIN_TIMER_FREQ) ?
CONFIG_LP_IPQ806X_TIMER_FREQ : MIN_TIMER_FREQ;
}
uint64_t timer_raw_value(void)
{
uint64_t rawv = readl((void *)CONFIG_LP_IPQ806X_TIMER_REG);
/*
* This is extremely crude, but it kicks in only for the case when the
* timer clock frequency is below 1MHz, which should never be the case
* on a properly configured system. The compiler will eliminate the
* check as long as config value exceeds 1MHz.
*/
if (CONFIG_LP_IPQ806X_TIMER_FREQ < MIN_TIMER_FREQ)
rawv *= (MIN_TIMER_FREQ / CONFIG_LP_IPQ806X_TIMER_FREQ);
return rawv;
}