[U-Boot] [PATCH v2] arm925t: Fix CONFIG_SYS_HZ to 1000

Dirk Behme dirk.behme at googlemail.com
Wed Apr 22 16:51:59 CEST 2009


Ladislav Michl wrote:
> Let CONFIG_SYS_HZ to have value of 1000 effectively fixing all users of
> get_timer.
> 
> Changes since original version:
> * Set PTV=2 (divisor 8) for boards using 12MHz timer clock source to
>   improve timer resolution.
> 
> Signed-off-by: Ladislav Michl <ladis at linux-mips.org>

Acked-by: Dirk Behme <dirk.behme at googlemail.com>

> diff --git a/cpu/arm925t/interrupts.c b/cpu/arm925t/interrupts.c
> index e5c77f7..ec2a978 100644
> --- a/cpu/arm925t/interrupts.c
> +++ b/cpu/arm925t/interrupts.c
> @@ -1,4 +1,7 @@
>  /*
> + * (C) Copyright 2009
> + * 2N Telekomunikace, <www.2n.cz>
> + *
>   * (C) Copyright 2003
>   * Texas Instruments, <www.ti.com>
>   *
> @@ -37,7 +40,8 @@
>  #include <configs/omap1510.h>
>  #include <asm/io.h>
>  
> -#define TIMER_LOAD_VAL 0xffffffff
> +#define TIMER_LOAD_VAL	0xffffffff
> +#define TIMER_CLOCK	(CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV))
>  
>  static uint32_t timestamp;
>  static uint32_t lastdec;
> @@ -79,85 +83,41 @@ void set_timer (ulong t)
>  /* delay x useconds AND preserve advance timestamp value */
>  void udelay (unsigned long usec)
>  {
> -	ulong tmo, tmp;
> -
> -	if (usec >= 1000) {		/* if "big" number, spread normalization to seconds */
> -		tmo = usec / 1000;	/* start to normalize for usec to ticks per sec */
> -		tmo *= CONFIG_SYS_HZ;	/* find number of "ticks" to wait to achieve target */
> -		tmo /= 1000;		/* finish normalize. */
> -	} else {			/* else small number, don't kill it prior to HZ multiply */
> -		tmo = usec * CONFIG_SYS_HZ;
> -		tmo /= (1000*1000);
> +	int32_t tmo = usec * (TIMER_CLOCK / 1000) / 1000;
> +	uint32_t now, last = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
> +
> +	while (tmo > 0) {
> +		now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
> +		if (last < now) /* count down timer underflow */
> +			tmo -= TIMER_LOAD_VAL - now + last;
> +		else
> +			tmo -= last - now;
> +		last = now;
>  	}
> -
> -	tmp = get_timer (0);		/* get current timestamp */
> -	if ((tmo + tmp + 1) < tmp)	/* if setting this fordward will roll time stamp */
> -		reset_timer_masked ();	/* reset "advancing" timestamp to 0, set lastdec value */
> -	else
> -		tmo += tmp;		/* else, set advancing stamp wake up time */
> -
> -	while (get_timer_masked () < tmo) /* loop till event */
> -		/*NOP*/;
>  }
>  
>  void reset_timer_masked (void)
>  {
>  	/* reset time */
> -	lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
> +	lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
> +			(TIMER_CLOCK / CONFIG_SYS_HZ);
>  	timestamp = 0;	       /* start "advancing" time stamp from 0 */
>  }
>  
>  ulong get_timer_masked (void)
>  {
> -	uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
> -
> -	if (lastdec >= now) {		/* normal mode (non roll) */
> -		/* normal mode */
> -		timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
> -	} else {			/* we have overflow of the count down timer */
> -		/* nts = ts + ld + (TLV - now)
> -		 * ts=old stamp, ld=time that passed before passing through -1
> -		 * (TLV-now) amount of time after passing though -1
> -		 * nts = new "advancing time stamp"...it could also roll and cause problems.
> -		 */
> -		timestamp += lastdec + TIMER_LOAD_VAL - now;
> -	}
> +	uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) /
> +			(TIMER_CLOCK / CONFIG_SYS_HZ);
> +	if (lastdec < now)	/* count down timer underflow */
> +		timestamp += TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ) -
> +				now + lastdec;
> +	else
> +		timestamp += lastdec - now;
>  	lastdec = now;
>  
>  	return timestamp;
>  }
>  
> -/* waits specified delay value and resets timestamp */
> -void udelay_masked (unsigned long usec)
> -{
> -#ifdef CONFIG_INNOVATOROMAP1510
> -	#define LOOPS_PER_MSEC 60 /* tuned on omap1510 */
> -	volatile int i, time_remaining = LOOPS_PER_MSEC*usec;
> -	for (i=time_remaining; i>0; i--) { }
> -#else
> -
> -	ulong tmo;
> -	ulong endtime;
> -	signed long diff;
> -
> -	if (usec >= 1000) {		/* if "big" number, spread normalization to seconds */
> -		tmo = usec / 1000;	/* start to normalize for usec to ticks per sec */
> -		tmo *= CONFIG_SYS_HZ;	/* find number of "ticks" to wait to achieve target */
> -		tmo /= 1000;		/* finish normalize. */
> -	} else {			/* else small number, don't kill it prior to HZ multiply */
> -		tmo = usec * CONFIG_SYS_HZ;
> -		tmo /= (1000*1000);
> -	}
> -
> -	endtime = get_timer_masked () + tmo;
> -
> -	do {
> -		ulong now = get_timer_masked ();
> -		diff = endtime - now;
> -	} while (diff >= 0);
> -#endif
> -}
> -
>  /*
>   * This function is derived from PowerPC code (read timebase as long long).
>   * On ARM it just returns the timer value.
> diff --git a/include/configs/SX1.h b/include/configs/SX1.h
> index caa6592..6149276 100644
> --- a/include/configs/SX1.h
> +++ b/include/configs/SX1.h
> @@ -135,12 +135,12 @@
>  
>  #define CONFIG_SYS_LOAD_ADDR		0x10000000	/* default load address */
>  
> -/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
> +/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.
>   * This time is further subdivided by a local divisor.
>   */
>  #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE	/* use timer 1 */
> -#define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
> -#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
> +#define CONFIG_SYS_PTV		2	/* Divisor: 2^(PTV+1) => 8 */
> +#define CONFIG_SYS_HZ		1000
>  
>  /*-----------------------------------------------------------------------
>   * Stack sizes
> diff --git a/include/configs/netstar.h b/include/configs/netstar.h
> index 39560de..5cfee66 100644
> --- a/include/configs/netstar.h
> +++ b/include/configs/netstar.h
> @@ -222,12 +222,12 @@
>  
>  #define CONFIG_SYS_LOAD_ADDR		PHYS_SDRAM_1 + 0x400000	/* default load address */
>  
> -/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
> +/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.
>   * This time is further subdivided by a local divisor.
>   */
>  #define CONFIG_SYS_TIMERBASE		OMAP1510_TIMER1_BASE
> -#define CONFIG_SYS_PTV			7		/* 2^(pvt+1), divide by 256 */
> -#define CONFIG_SYS_HZ			((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
> +#define CONFIG_SYS_PTV			7
> +#define CONFIG_SYS_HZ			1000
>  
>  #define OMAP5910_DPLL_DIV	1
>  #define OMAP5910_DPLL_MUL	((CONFIG_SYS_CLK_FREQ * \
> diff --git a/include/configs/omap1510inn.h b/include/configs/omap1510inn.h
> index 6c1c5ec..8408209 100644
> --- a/include/configs/omap1510inn.h
> +++ b/include/configs/omap1510inn.h
> @@ -132,12 +132,12 @@
>  
>  #define CONFIG_SYS_LOAD_ADDR		0x10000000	/* default load address */
>  
> -/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
> +/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.
>   * This time is further subdivided by a local divisor.
>   */
>  #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE	/* use timer 1 */
> -#define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
> -#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
> +#define CONFIG_SYS_PTV		2	/* Divisor: 2^(PTV+1) => 8 */
> +#define CONFIG_SYS_HZ		1000
>  
>  /*-----------------------------------------------------------------------
>   * Stack sizes
> diff --git a/include/configs/voiceblue.h b/include/configs/voiceblue.h
> index 3f97843..aa8efaa 100644
> --- a/include/configs/voiceblue.h
> +++ b/include/configs/voiceblue.h
> @@ -210,12 +210,12 @@
>  #define CONFIG_SYS_MEMTEST_START	PHYS_SDRAM_1
>  #define CONFIG_SYS_MEMTEST_END		PHYS_SDRAM_1 + PHYS_SDRAM_1_SIZE - PHYS_SDRAM_1_RESERVED
>  
> -/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
> +/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.
>   * This time is further subdivided by a local divisor.
>   */
>  #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE
>  #define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
> -#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
> +#define CONFIG_SYS_HZ		1000
>  
>  #define OMAP5910_DPLL_DIV	1
>  #define OMAP5910_DPLL_MUL	((CONFIG_SYS_CLK_FREQ * \
> 



More information about the U-Boot mailing list