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	Signed-off-by: Wolfgang Denk <wd@denx.de> [trini: Fixup common/cmd_io.c] Signed-off-by: Tom Rini <trini@ti.com>
		
			
				
	
	
		
			121 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			121 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * (C) Copyright 2007-2008
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|  * Stelian Pop <stelian@popies.net>
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|  * Lead Tech Design <www.leadtechdesign.com>
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|  *
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|  * SPDX-License-Identifier:	GPL-2.0+
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|  */
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| 
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| #include <common.h>
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| #include <asm/io.h>
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| #include <asm/arch/hardware.h>
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| #include <asm/arch/at91_pit.h>
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| #include <asm/arch/at91_pmc.h>
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| #include <asm/arch/clk.h>
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| #include <div64.h>
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| 
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| #if !defined(CONFIG_AT91FAMILY)
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| # error You need to define CONFIG_AT91FAMILY in your board config!
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| #endif
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| 
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| DECLARE_GLOBAL_DATA_PTR;
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| 
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| /*
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|  * We're using the AT91CAP9/SAM9 PITC in 32 bit mode, by
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|  * setting the 20 bit counter period to its maximum (0xfffff).
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|  * (See the relevant data sheets to understand that this really works)
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|  *
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|  * We do also mimic the typical powerpc way of incrementing
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|  * two 32 bit registers called tbl and tbu.
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|  *
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|  * Those registers increment at 1/16 the main clock rate.
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|  */
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| 
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| #define TIMER_LOAD_VAL	0xfffff
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| 
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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, gd->arch.timer_rate_hz);
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| 
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| 	return tick;
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| }
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| 
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| static inline unsigned long long usec_to_tick(unsigned long long usec)
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| {
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| 	usec *= gd->arch.timer_rate_hz;
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| 	do_div(usec, 1000000);
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| 
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| 	return usec;
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| }
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| 
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| /*
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|  * Use the PITC in full 32 bit incrementing mode
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|  */
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| int timer_init(void)
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| {
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| 	at91_pmc_t *pmc = (at91_pmc_t *) ATMEL_BASE_PMC;
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| 	at91_pit_t *pit = (at91_pit_t *) ATMEL_BASE_PIT;
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| 
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| 	/* Enable PITC Clock */
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| 	writel(1 << ATMEL_ID_SYS, &pmc->pcer);
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| 
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| 	/* Enable PITC */
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| 	writel(TIMER_LOAD_VAL | AT91_PIT_MR_EN , &pit->mr);
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| 
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| 	gd->arch.timer_rate_hz = gd->arch.mck_rate_hz / 16;
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| 	gd->arch.tbu = gd->arch.tbl = 0;
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Get the current 64 bit timer tick count
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|  */
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| unsigned long long get_ticks(void)
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| {
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| 	at91_pit_t *pit = (at91_pit_t *) ATMEL_BASE_PIT;
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| 
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| 	ulong now = readl(&pit->piir);
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| 
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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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| 
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| void __udelay(unsigned long usec)
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| {
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| 	unsigned long long start;
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| 	ulong tmo;
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| 
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| 	start = get_ticks();		/* get current timestamp */
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| 	tmo = usec_to_tick(usec);	/* convert usecs to ticks */
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| 	while ((get_ticks() - start) < tmo)
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| 		;			/* loop till time has passed */
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| }
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| 
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| /*
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|  * get_timer(base) can be used to check for timeouts or
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|  * to measure elasped time relative to an event:
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|  *
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|  * ulong start_time = get_timer(0) sets start_time to the current
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|  * time value.
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|  * get_timer(start_time) returns the time elapsed since then.
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|  *
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|  * The time is used in CONFIG_SYS_HZ units!
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|  */
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| ulong get_timer(ulong base)
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| {
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| 	return tick_to_time(get_ticks()) - base;
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| }
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| 
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| /*
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|  * Return 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 gd->arch.timer_rate_hz;
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| }
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