79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/*
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* (C) Copyright 2010 Juergen Beisert - Pengutronix
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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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*/
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#include <common.h>
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#include <init.h>
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#include <clock.h>
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#include <notifier.h>
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#include <mach/imx-regs.h>
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#include <mach/clock.h>
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#include <io.h>
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#define TIMROTCTRL 0x00
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#define TIMCTRL1 0x40
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#define TIMCTRL1_SET 0x44
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#define TIMCTRL1_CLR 0x48
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#define TIMCTRL1_TOG 0x4c
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# define TIMCTRL_RELOAD (1 << 6)
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# define TIMCTRL_UPDATE (1 << 7)
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# define TIMCTRL_PRESCALE(x) ((x & 0x3) << 4)
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# define TIMCTRL_SELECT(x) (x & 0xf)
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#define TIMCOUNT1 0x50
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static const unsigned long timer_base = IMX_TIM1_BASE;
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#define CLOCK_TICK_RATE (32000)
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static uint64_t imx23_clocksource_read(void)
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{
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/* only the upper bits are the valid */
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return ~(readl(timer_base + TIMCOUNT1) >> 16);
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}
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static struct clocksource cs = {
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.read = imx23_clocksource_read,
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.mask = CLOCKSOURCE_MASK(16),
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.shift = 10,
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};
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static int imx23_clocksource_clock_change(struct notifier_block *nb, unsigned long event, void *data)
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{
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cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE/*imx_get_xclk()*/, cs.shift);
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return 0;
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}
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static struct notifier_block imx23_clock_notifier = {
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.notifier_call = imx23_clocksource_clock_change,
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};
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static int clocksource_init(void)
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{
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/* enable the whole timer block */
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writel(0x3e000000, timer_base + TIMROTCTRL);
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/* setup general purpose timer 1 */
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writel(0x00000000, timer_base + TIMCTRL1);
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writel(TIMCTRL_UPDATE, timer_base + TIMCTRL1);
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writel(0x0000ffff, timer_base + TIMCOUNT1);
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writel(TIMCTRL_UPDATE | TIMCTRL_RELOAD | TIMCTRL_PRESCALE(0) | TIMCTRL_SELECT(8), timer_base + TIMCTRL1);
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cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE/*imx_get_xclk()*/, cs.shift);
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init_clock(&cs);
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clock_register_client(&imx23_clock_notifier);
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return 0;
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}
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core_initcall(clocksource_init);
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