u-boot/arch/x86/lib/tsc_timer.c
Simon Glass d0b6f247a1 x86: Re-enable PCAT timer 2 for beeping
While we don't want PCAT timers for timing, we want timer 2 so that we can
still make a beep. Re-purpose the PCAT driver for this, and enable it in
coreboot.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-05-13 13:33:21 -07:00

107 lines
2.3 KiB
C

/*
* Copyright (c) 2012 The Chromium OS Authors.
*
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <malloc.h>
#include <asm/io.h>
#include <asm/i8254.h>
#include <asm/ibmpc.h>
#include <asm/msr.h>
#include <asm/u-boot-x86.h>
DECLARE_GLOBAL_DATA_PTR;
void timer_set_base(u64 base)
{
gd->arch.tsc_base = base;
}
/*
* Get the number of CPU time counter ticks since it was read first time after
* restart. This yields a free running counter guaranteed to take almost 6
* years to wrap around even at 100GHz clock rate.
*/
u64 get_ticks(void)
{
u64 now_tick = rdtsc();
/* We assume that 0 means the base hasn't been set yet */
if (!gd->arch.tsc_base)
panic("No tick base available");
return now_tick - gd->arch.tsc_base;
}
#define PLATFORM_INFO_MSR 0xce
/* Get the speed of the TSC timer in MHz */
unsigned long get_tbclk_mhz(void)
{
u32 ratio;
u64 platform_info = native_read_msr(PLATFORM_INFO_MSR);
/* 100MHz times Max Non Turbo ratio */
ratio = (platform_info >> 8) & 0xff;
return 100 * ratio;
}
unsigned long get_tbclk(void)
{
return get_tbclk_mhz() * 1000 * 1000;
}
static ulong get_ms_timer(void)
{
return (get_ticks() * 1000) / get_tbclk();
}
ulong get_timer(ulong base)
{
return get_ms_timer() - base;
}
ulong timer_get_us(void)
{
return get_ticks() / get_tbclk_mhz();
}
ulong timer_get_boot_us(void)
{
return timer_get_us();
}
void __udelay(unsigned long usec)
{
u64 now = get_ticks();
u64 stop;
stop = now + usec * get_tbclk_mhz();
while ((int64_t)(stop - get_ticks()) > 0)
;
}
int timer_init(void)
{
#ifdef CONFIG_SYS_PCAT_TIMER
/* Set up the PCAT timer if required */
pcat_timer_init();
#endif
return 0;
}