u-boot/arch/arm/cpu/arm926ejs/lpc32xx/timer.c

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/*
* Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/clk.h>
#include <asm/arch/timer.h>
#include <asm/io.h>
static struct timer_regs *timer0 = (struct timer_regs *)TIMER0_BASE;
static struct timer_regs *timer1 = (struct timer_regs *)TIMER1_BASE;
static struct clk_pm_regs *clk = (struct clk_pm_regs *)CLK_PM_BASE;
static void lpc32xx_timer_clock(u32 bit, int enable)
{
if (enable)
setbits_le32(&clk->timclk_ctrl1, bit);
else
clrbits_le32(&clk->timclk_ctrl1, bit);
}
static void lpc32xx_timer_reset(struct timer_regs *timer, u32 freq)
{
writel(TIMER_TCR_COUNTER_RESET, &timer->tcr);
writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
writel(0, &timer->tc);
writel(0, &timer->pr);
/* Count mode is every rising PCLK edge */
writel(TIMER_CTCR_MODE_TIMER, &timer->ctcr);
/* Set prescale counter value */
writel((get_periph_clk_rate() / freq) - 1, &timer->pr);
}
static void lpc32xx_timer_count(struct timer_regs *timer, int enable)
{
if (enable)
writel(TIMER_TCR_COUNTER_ENABLE, &timer->tcr);
else
writel(TIMER_TCR_COUNTER_DISABLE, &timer->tcr);
}
int timer_init(void)
{
lpc32xx_timer_clock(CLK_TIMCLK_TIMER0, 1);
lpc32xx_timer_reset(timer0, CONFIG_SYS_HZ);
lpc32xx_timer_count(timer0, 1);
return 0;
}
ulong get_timer(ulong base)
{
return readl(&timer0->tc) - base;
}
void __udelay(unsigned long usec)
{
lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 1);
lpc32xx_timer_reset(timer1, CONFIG_SYS_HZ * 1000);
lpc32xx_timer_count(timer1, 1);
while (readl(&timer1->tc) < usec)
/* NOP */;
lpc32xx_timer_count(timer1, 0);
lpc32xx_timer_clock(CLK_TIMCLK_TIMER1, 0);
}
unsigned long long get_ticks(void)
{
return get_timer(0);
}
ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}