From f6145c3c15789123f6b4a9ce64a517048e753762 Mon Sep 17 00:00:00 2001 From: Jordan Crouse Date: Wed, 19 Mar 2008 23:56:58 +0000 Subject: libpayload: The initial chunk of code writen by AMD This is the initial chunk of code written by me and copyrighted by AMD. Includes everything but a few files that we pulled from outside sources. Signed-off-by: Jordan Crouse Acked-by: Uwe Hermann git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3170 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1 --- payloads/libpayload/i386/timer.c | 92 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 payloads/libpayload/i386/timer.c (limited to 'payloads/libpayload/i386/timer.c') diff --git a/payloads/libpayload/i386/timer.c b/payloads/libpayload/i386/timer.c new file mode 100644 index 0000000000..72a3ee8f48 --- /dev/null +++ b/payloads/libpayload/i386/timer.c @@ -0,0 +1,92 @@ +/* + * This file is part of the libpayload project. + * + * Copyright (C) 2008 Advanced Micro Devices, 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 +#include + +static unsigned int cpu_khz; + +/* Calculate the speed of the processor for use in delays */ + +void get_cpu_speed(void) +{ + unsigned long long start, end; + + /* Set up the PPC port - disable the speaker, + * enable the T2 gate */ + + outb((inb(0x61) & ~0x02) | 0x01, 0x61); + + /* Set the PIT to Mode 0, counter 2, word access */ + outb(0xB0, 0x43); + + /* Load the counter with 0xFFFF */ + + outb(0xFF, 0x42); + outb(0xFF, 0x42); + + /* Read the number of ticks during the period */ + + start = rdtsc(); + while(!(inb(0x61) & 0x20)); + end = rdtsc(); + + /* The clock rate is 1193180 Hz + * the number of miliseconds for a period + * of 0xFFFF is 1193180 / (0xFFFF * 1000) + * or .0182. Multiply that by the number of + * measured clocks to get the khz value + */ + + cpu_khz = + (unsigned int ) ((end - start) * 1193180U / (1000 * 0xFFFF)); +} + +/* Global delay functions */ + +static inline void _delay(unsigned int delta) +{ + unsigned long long timeout = rdtsc() + delta; + while (rdtsc() < timeout); +} + +void ndelay(unsigned int n) +{ + _delay(n * cpu_khz / 1000000); +} + +void mdelay(unsigned int m) +{ + _delay(m * cpu_khz); +} + +void delay(unsigned int s) +{ + _delay(s * cpu_khz * 1000); +} -- cgit v1.2.3