Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Peter Pearse <peter.pearse@arm.com>master
Jean-Christophe PLAGNIOL-VILLARD
15 years ago
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/*
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* (C) Copyright 2002 |
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* Sysgo Real-Time Solutions, GmbH <www.elinos.com> |
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* Marius Groeger <mgroeger@sysgo.de> |
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* |
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* (C) Copyright 2002 |
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* David Mueller, ELSOFT AG, <d.mueller@elsoft.ch> |
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* |
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* (C) Copyright 2003 |
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* Texas Instruments, <www.ti.com> |
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* Kshitij Gupta <Kshitij@ti.com> |
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* |
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* (C) Copyright 2004 |
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* ARM Ltd. |
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* Philippe Robin, <philippe.robin@arm.com> |
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* |
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* See file CREDITS for list of people who contributed to this |
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* project. |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License as |
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* published by the Free Software Foundation; either version 2 of |
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* the License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
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* MA 02111-1307 USA |
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*/ |
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#include <common.h> |
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#include <div64.h> |
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/* The Integrator/CP timer1 is clocked at 1MHz
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* can be divided by 16 or 256 |
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* and can be set up as a 32-bit timer |
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*/ |
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/* U-Boot expects a 32 bit timer, running at CONFIG_SYS_HZ */ |
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/* Keep total timer count to avoid losing decrements < div_timer */ |
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static unsigned long long total_count = 0; |
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static unsigned long long lastdec; /* Timer reading at last call */ |
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static unsigned long long div_clock = 1; /* Divisor applied to timer clock */ |
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static unsigned long long div_timer = 1; /* Divisor to convert timer reading
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* change to U-Boot ticks |
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*/ |
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/* CONFIG_SYS_HZ = CONFIG_SYS_HZ_CLOCK/(div_clock * div_timer) */ |
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static ulong timestamp; /* U-Boot ticks since startup */ |
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#define TIMER_LOAD_VAL ((ulong)0xFFFFFFFF) |
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#define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+4)) |
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/* all function return values in U-Boot ticks i.e. (1/CONFIG_SYS_HZ) sec
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* - unless otherwise stated |
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*/ |
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/* starts up a counter
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* - the Integrator/CP timer can be set up to issue an interrupt */ |
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int timer_init (void) |
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{ |
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/* Load timer with initial value */ |
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*(volatile ulong *)(CONFIG_SYS_TIMERBASE + 0) = TIMER_LOAD_VAL; |
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/* Set timer to be
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* enabled 1 |
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* periodic 1 |
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* no interrupts 0 |
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* X 0 |
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* divider 1 00 == less rounding error |
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* 32 bit 1 |
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* wrapping 0 |
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*/ |
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*(volatile ulong *)(CONFIG_SYS_TIMERBASE + 8) = 0x000000C2; |
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/* init the timestamp */ |
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total_count = 0ULL; |
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reset_timer_masked(); |
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div_timer = (unsigned long long)(CONFIG_SYS_HZ_CLOCK / CONFIG_SYS_HZ); |
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div_timer /= div_clock; |
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return (0); |
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} |
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/*
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* timer without interrupts |
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*/ |
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void reset_timer (void) |
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{ |
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reset_timer_masked (); |
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} |
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ulong get_timer (ulong base_ticks) |
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{ |
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return get_timer_masked () - base_ticks; |
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} |
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void set_timer (ulong ticks) |
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{ |
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timestamp = ticks; |
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total_count = (unsigned long long)ticks * div_timer; |
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} |
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/* delay usec useconds */ |
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void udelay (unsigned long usec) |
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{ |
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ulong tmo, tmp; |
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/* Convert to U-Boot ticks */ |
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tmo = usec * CONFIG_SYS_HZ; |
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tmo /= (1000000L); |
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tmp = get_timer_masked(); /* get current timestamp */ |
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tmo += tmp; /* form target timestamp */ |
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while (get_timer_masked () < tmo) {/* loop till event */ |
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/*NOP*/; |
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} |
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} |
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void reset_timer_masked (void) |
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{ |
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/* capure current decrementer value */ |
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lastdec = (unsigned long long)READ_TIMER; |
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/* start "advancing" time stamp from 0 */ |
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timestamp = 0L; |
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} |
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/* converts the timer reading to U-Boot ticks */ |
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/* the timestamp is the number of ticks since reset */ |
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ulong get_timer_masked (void) |
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{ |
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/* get current count */ |
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unsigned long long now = (unsigned long long)READ_TIMER; |
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if(now > lastdec) { |
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/* Must have wrapped */ |
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total_count += lastdec + TIMER_LOAD_VAL + 1 - now; |
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} else { |
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total_count += lastdec - now; |
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} |
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lastdec = now; |
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/* Reuse "now" */ |
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now = total_count; |
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do_div(now, div_timer); |
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timestamp = now; |
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return timestamp; |
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} |
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/* waits specified delay value and resets timestamp */ |
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void udelay_masked (unsigned long usec) |
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{ |
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udelay(usec); |
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} |
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/*
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* This function is derived from PowerPC code (read timebase as long long). |
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* On ARM it just returns the timer value. |
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*/ |
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unsigned long long get_ticks(void) |
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{ |
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return (unsigned long long)get_timer(0); |
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} |
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/*
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* Return the timebase clock frequency |
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* i.e. how often the timer decrements |
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*/ |
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ulong get_tbclk (void) |
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{ |
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return (ulong)(((unsigned long long)CONFIG_SYS_HZ_CLOCK)/div_clock); |
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} |
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