122 lines
2.6 KiB
C
122 lines
2.6 KiB
C
/*
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* (C) Copyright 2007
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* Sascha Hauer, Pengutronix
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*
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* (C) Copyright 2009 Freescale Semiconductor, Inc.
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/io.h>
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#include <div64.h>
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#include <asm/arch/imx-regs.h>
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#include <asm/arch/clock.h>
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/* General purpose timers registers */
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struct mxc_gpt {
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unsigned int control;
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unsigned int prescaler;
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unsigned int status;
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unsigned int nouse[6];
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unsigned int counter;
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};
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static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
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/* General purpose timers bitfields */
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#define GPTCR_SWR (1 << 15) /* Software reset */
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#define GPTCR_FRR (1 << 9) /* Freerun / restart */
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#define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */
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#define GPTCR_TEN 1 /* Timer enable */
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DECLARE_GLOBAL_DATA_PTR;
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static inline unsigned long long tick_to_time(unsigned long long tick)
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{
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tick *= CONFIG_SYS_HZ;
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do_div(tick, MXC_CLK32);
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return tick;
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}
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static inline unsigned long long us_to_tick(unsigned long long usec)
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{
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usec = usec * MXC_CLK32 + 999999;
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do_div(usec, 1000000);
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return usec;
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}
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int timer_init(void)
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{
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int i;
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/* setup GP Timer 1 */
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__raw_writel(GPTCR_SWR, &cur_gpt->control);
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/* We have no udelay by now */
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for (i = 0; i < 100; i++)
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__raw_writel(0, &cur_gpt->control);
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__raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
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/* Freerun Mode, PERCLK1 input */
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i = __raw_readl(&cur_gpt->control);
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__raw_writel(i | GPTCR_CLKSOURCE_32 | GPTCR_TEN, &cur_gpt->control);
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gd->arch.tbl = __raw_readl(&cur_gpt->counter);
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gd->arch.tbu = 0;
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return 0;
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}
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unsigned long long get_ticks(void)
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{
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ulong now = __raw_readl(&cur_gpt->counter); /* current tick value */
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/* increment tbu if tbl has rolled over */
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if (now < gd->arch.tbl)
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gd->arch.tbu++;
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gd->arch.tbl = now;
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return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
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}
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ulong get_timer_masked(void)
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{
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/*
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* get_ticks() returns a long long (64 bit), it wraps in
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* 2^64 / MXC_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
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* 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
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* 5 * 10^6 days - long enough.
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*/
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return tick_to_time(get_ticks());
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}
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ulong get_timer(ulong base)
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{
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return get_timer_masked() - base;
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}
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/* delay x useconds AND preserve advance timstamp value */
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void __udelay(unsigned long usec)
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{
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unsigned long long tmp;
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ulong tmo;
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tmo = us_to_tick(usec);
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tmp = get_ticks() + tmo; /* get current timestamp */
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while (get_ticks() < tmp) /* loop till event */
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/*NOP*/;
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}
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/*
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* This function is derived from PowerPC code (timebase clock frequency).
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* On ARM it returns the number of timer ticks per second.
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*/
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ulong get_tbclk(void)
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{
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return MXC_CLK32;
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}
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