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#include <common.h>
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#include <asm/io.h>
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#include <asm/arch/imx-regs.h>
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#include <asm/arch/clock.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define timestamp (gd->tbl)
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#define lastinc (gd->lastinc)
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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_CLKSOURCE_32 (0x100<<6) /* Clock source */
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#define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */
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#define GPTCR_TEN (1) /* Timer enable */
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#define GPTPR_VAL (66)
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#define TIMER_FREQ_HZ mxc_get_clock(MXC_IPG_CLK)
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static inline unsigned long long tick_to_time(unsigned long long tick)
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tick *= CONFIG_SYS_HZ;
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do_div(tick, TIMER_FREQ_HZ);
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static inline unsigned long long us_to_tick(unsigned long long usec)
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usec *= TIMER_FREQ_HZ;
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do_div(usec, 1000000);
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int timer_init(void)
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for (i = 0; i < 100; i++)
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writel(0, &gpt->ctrl); /* We have no udelay by now */
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writel(GPTPR_VAL, &gpt->pre);
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/* Freerun Mode, PERCLK1 input */
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writel(readl(&gpt->ctrl) |
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GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
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void reset_timer_masked(void)
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unsigned long long get_ticks(void)
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struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
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ulong now = readl(&gpt->counter); /* current tick value */
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writel(0, &gpt->ctrl);
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/* Freerun Mode, PERCLK1 input */
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writel(GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
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* normal mode (non roll)
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* move stamp forward with absolut diff ticks
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timestamp += (now - lastinc);
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/* we have rollover of incrementer */
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timestamp += (0xFFFFFFFF - lastinc) + now;
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inline ulong get_timer_masked(void)
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ulong get_timer_masked(void)
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struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
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ulong val = readl(&gpt->counter);
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* get_ticks() returns a long long (64 bit), it wraps in
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* 2^64 / CONFIG_MX25_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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return tick_to_time(get_ticks());
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ulong get_timer(ulong base)
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tmp = get_timer_masked();
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if (tmp <= (base * 1000)) {
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tmp += (0xffffffff - base);
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return (tmp / 1000) - base;
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return get_timer_masked() - base;
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* delay x useconds AND preserve advance timstamp value
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* GPTCNT is now supposed to tick 1 by 1 us.
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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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tmp = get_timer_masked(); /* get current timestamp */
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/* if setting this forward will roll time stamp */
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if ((usec + tmp + 1) < tmp) {
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/* reset "advancing" timestamp to 0, set lastinc value */
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reset_timer_masked();
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/* else, set advancing stamp wake up time */
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while (get_timer_masked() < tmp) /* loop till event */
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unsigned long long tmp;
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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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* 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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ulong get_tbclk(void)
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return TIMER_FREQ_HZ;