5c0b7abe78
The timekeeping code in libpayload was dependent on rdtsc, and when it was split up by arch, that code was duplicated even though it was mostly the same. This change factors out actually reading the count from the timer and the speed of the timer and puts the definitions of ndelay, udelay, mdelay and delay into generic code. Then, in x86, the timer_hz and timer_get_raw_value functions which used to be in depthcharge were moved over to libpayload's arch/x86/timer.c. In ARM where there isn't a single, canonical timer, those functions are omitted with the intention that they'll be implemented by a specific timer driver chosen elsewhere. Change-Id: I9c919bed712ace941f417c1d58679d667b2d8269 Signed-off-by: Gabe Black <gabeblack@google.com> Reviewed-on: http://review.coreboot.org/2717 Tested-by: build bot (Jenkins) Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
88 lines
2.8 KiB
C
88 lines
2.8 KiB
C
/*
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* This file is part of the libpayload project.
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*
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* Copyright (C) 2008 Advanced Micro Devices, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/**
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* @file x86/timer.c
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* x86 specific timer routines
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*/
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#include <libpayload.h>
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#include <arch/rdtsc.h>
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/**
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* @ingroup arch
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* Global variable containing the speed of the processor in KHz.
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*/
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uint32_t cpu_khz;
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/**
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* Calculate the speed of the processor for use in delays.
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*
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* @return The CPU speed in kHz.
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*/
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unsigned int get_cpu_speed(void)
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{
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unsigned long long start, end;
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const uint32_t clock_rate = 1193182; // 1.193182 MHz
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const uint16_t interval = (2 * clock_rate) / 1000; // 2 ms
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/* Set up the PPC port - disable the speaker, enable the T2 gate. */
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outb((inb(0x61) & ~0x02) | 0x01, 0x61);
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/* Set the PIT to Mode 0, counter 2, word access. */
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outb(0xB0, 0x43);
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/* Load the interval into the counter. */
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outb(interval & 0xff, 0x42);
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outb((interval >> 8) & 0xff, 0x42);
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/* Read the number of ticks during the period. */
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start = rdtsc();
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while (!(inb(0x61) & 0x20)) ;
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end = rdtsc();
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/*
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* The number of milliseconds for a period is
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* clock_rate / (interval * 1000). Multiply that by the number of
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* measured clocks to get the kHz value.
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*/
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cpu_khz = (end - start) * clock_rate / (1000 * interval);
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return cpu_khz;
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}
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uint64_t timer_hz(void)
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{
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return lib_sysinfo.cpu_khz * 1000;
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}
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uint64_t timer_raw_value(void)
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{
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return rdtsc();
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}
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