111 lines
2.6 KiB
C
111 lines
2.6 KiB
C
/*
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* (C) Copyright 2010 Quantenna Communications Inc.
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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 "ruby.h"
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#define TIMER_NO_IN_USE 0x0
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#define TIMER_MAX_VALUE 0xFFFFFFFF
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#define TIMER_TICK_PER_SYS_TICK (gd->bus_clk / CONFIG_SYS_HZ)
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#define TIMER_TICK_PER_USEC(usec) (gd->bus_clk * (usec) / 1000000)
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#define TIMER_MAX_USEC_PER_ITER() (0xFFFFFFFF / gd->bus_clk)
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/* Monotonic incrementing timer */
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static unsigned long long timestamp = 0;
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static inline ulong read_timer(void)
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{
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return ((TIMER_MAX_VALUE - readl(RUBY_TIMER_VALUE(TIMER_NO_IN_USE))));
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}
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static unsigned long long tick(void)
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{
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/* Internal tick units. Last snapshot. */
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static ulong last_tick = 0;
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ulong now = read_timer();
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if (now >= last_tick) {
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/* normal mode */
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timestamp += now - last_tick;
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} else {
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/* we have an overflow ... */
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timestamp += now + TIMER_MAX_VALUE - last_tick;
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}
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last_tick = now;
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return timestamp;
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}
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static void setup_timer(ulong val)
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{
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writel(0, RUBY_TIMER_CONTROL(TIMER_NO_IN_USE));
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writel(TIMER_MAX_VALUE - val, RUBY_TIMER_LOAD_COUNT(TIMER_NO_IN_USE));
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writel(RUBY_TIMER_ENABLE, RUBY_TIMER_CONTROL(TIMER_NO_IN_USE));
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}
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ulong get_timer(ulong base)
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{
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DECLARE_GLOBAL_DATA_PTR;
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return tick() / TIMER_TICK_PER_SYS_TICK - base;
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}
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void udelay(unsigned long usec)
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{
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DECLARE_GLOBAL_DATA_PTR;
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const unsigned long usec_per_iter = TIMER_MAX_USEC_PER_ITER();
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const unsigned long tick_per_iter = TIMER_TICK_PER_USEC(usec_per_iter);
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const unsigned long remain_tick = TIMER_TICK_PER_USEC(usec % usec_per_iter);
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while(usec) {
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unsigned long long future = tick();
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if (usec < usec_per_iter) {
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future += remain_tick;
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usec = 0;
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} else {
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future += tick_per_iter;
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usec -= usec_per_iter;
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}
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while(tick() < future);
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}
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}
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void reset_timer(void)
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{
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set_timer(0);
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}
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void set_timer(ulong t)
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{
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timestamp = t;
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setup_timer(t);
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}
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void board_timer_init(void)
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{
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reset_timer();
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}
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