[U-Boot] [IXP42x PATCH series v4 04/17] Fix IXP code to work after relocation was added

[Marek Vasut <marek.vasut@gmail.com>]

On Wednesday, April 06, 2011 11:49:05 PM Michael Schwingen wrote:
>  - jump to real flash location after reset before turning off flash mirror
>  - fix timer system to use HZ == 1000, remove broken interrupt-based code
> 
> Signed-off-by: Michael Schwingen <michael@schwingen.org>
> ---
> Changes for V2:
>  - fix patch description
> Changes for V3:
>  - use I/O accessors
>  - move timestamp variable from BSS to global data
>  - coding style fixes
> Changes for V4:
>  - add changelog
> 
>  arch/arm/cpu/ixp/cpu.c                 |    5 --
>  arch/arm/cpu/ixp/start.S               |   59 ++--------------
>  arch/arm/cpu/ixp/timer.c               |  124
> +++++++++++++++----------------- arch/arm/include/asm/arch-ixp/ixp425.h | 
>   5 +-
>  arch/arm/include/asm/global_data.h     |    3 +
>  5 files changed, 68 insertions(+), 128 deletions(-)
> 
> diff --git a/arch/arm/cpu/ixp/cpu.c b/arch/arm/cpu/ixp/cpu.c
> index ce275e5..942845d 100644
> --- a/arch/arm/cpu/ixp/cpu.c
> +++ b/arch/arm/cpu/ixp/cpu.c
> @@ -36,8 +36,6 @@
>  #include <asm/arch/ixp425.h>
>  #include <asm/system.h>
> 
> -ulong loops_per_jiffy;
> -
>  static void cache_flush(void);
> 
>  #if defined(CONFIG_DISPLAY_CPUINFO)
> @@ -51,17 +49,14 @@ int print_cpuinfo (void)
>  	puts("CPU:   Intel IXP425 at ");
>  	switch ((id & 0x000003f0) >> 4) {
>  	case 0x1c:
> -		loops_per_jiffy = 887467;
>  		speed = 533;
>  		break;
> 
>  	case 0x1d:
> -		loops_per_jiffy = 666016;
>  		speed = 400;
>  		break;
> 
>  	case 0x1f:
> -		loops_per_jiffy = 442901;
>  		speed = 266;
>  		break;
>  	}
> diff --git a/arch/arm/cpu/ixp/start.S b/arch/arm/cpu/ixp/start.S
> index 561c1f4..faa9a8f 100644
> --- a/arch/arm/cpu/ixp/start.S
> +++ b/arch/arm/cpu/ixp/start.S
> @@ -65,7 +65,8 @@
>  	.endm
> 
>  .globl _start
> -_start: b	reset
> +_start:
> +	ldr	pc, _reset
>  	ldr	pc, _undefined_instruction
>  	ldr	pc, _software_interrupt
>  	ldr	pc, _prefetch_abort
> @@ -74,6 +75,7 @@ _start: b	reset
>  	ldr	pc, _irq
>  	ldr	pc, _fiq
> 
> +_reset:                 .word reset
>  _undefined_instruction: .word undefined_instruction
>  _software_interrupt:	.word software_interrupt
>  _prefetch_abort:	.word prefetch_abort
> @@ -167,12 +169,6 @@ reset:
>  	str     r1, [r2]
> 
>  	/* make sure flash is visible at 0 */
> -#if 0
> -	ldr	r2, =IXP425_EXP_CFG0
> -	ldr     r1, [r2]
> -	orr     r1, r1, #0x80000000
> -	str     r1, [r2]
> -#endif
>  	mov	r1, #CONFIG_SYS_SDR_CONFIG
>  	ldr     r2, =IXP425_SDR_CONFIG
>  	str     r1, [r2]
> @@ -216,19 +212,6 @@ reset:
>  	str	r1, [r4]
>  	DELAY_FOR 0x4000, r0
> 
> -	/* copy */
> -	mov     r0, #0
> -	mov     r4, r0
> -	add     r2, r0, #CONFIG_SYS_MONITOR_LEN
> -	mov     r1, #0x10000000
> -	mov     r5, r1
> -
> -    30:
> -	ldr     r3, [r0], #4
> -	str     r3, [r1], #4
> -	cmp     r0, r2
> -	bne     30b
> -
>  	/* invalidate I & D caches & BTB */
>  	mcr	p15, 0, r0, c7, c7, 0
>  	CPWAIT	r0
> @@ -241,19 +224,12 @@ reset:
>  	mcr	p15, 0, r0, c7, c10, 4
>  	CPWAIT	r0
> 
> -	/* move flash to 0x50000000 */
> +	/* remove flash mirror at 0x00000000 */
>  	ldr	r2, =IXP425_EXP_CFG0
>  	ldr     r1, [r2]
>  	bic     r1, r1, #0x80000000
>  	str     r1, [r2]
> 
> -	nop
> -	nop
> -	nop
> -	nop
> -	nop
> -	nop
> -
>  	/* invalidate I & Data TLB */
>  	mcr	p15, 0, r0, c8, c7, 0
>  	CPWAIT r0
> @@ -269,7 +245,7 @@ reset:
>  	orr	r0,r0,#0x13
>  	msr	cpsr,r0
> 
> -/* Set stackpointer in internal RAM to call board_init_f */
> +/* Set initial stackpointer in SDRAM to call board_init_f */
>  call_board_init_f:
>  	ldr	sp, =(CONFIG_SYS_INIT_SP_ADDR)
>  	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
> @@ -580,28 +556,3 @@ reset_endless:
> 
>  	b	reset_endless
> 
> -#ifdef CONFIG_USE_IRQ
> -
> -.LC0:		.word	loops_per_jiffy
> -
> -/*
> - * 0 <= r0 <= 2000
> - */
> -.globl __udelay
> -__udelay:
> -	mov	r2,     #0x6800
> -	orr	r2, r2, #0x00db
> -	mul	r0, r2, r0
> -	ldr	r2, .LC0
> -	ldr	r2, [r2]		@ max = 0x0fffffff
> -	mov	r0, r0, lsr #11		@ max = 0x00003fff
> -	mov	r2, r2, lsr #11		@ max = 0x0003ffff
> -	mul	r0, r2, r0		@ max = 2^32-1
> -	movs	r0, r0, lsr #6
> -
> -delay_loop:
> -	subs	r0, r0, #1
> -	bne	delay_loop
> -	mov	pc, lr
> -
> -#endif /* CONFIG_USE_IRQ */
> diff --git a/arch/arm/cpu/ixp/timer.c b/arch/arm/cpu/ixp/timer.c
> index edf341f..7a44a08 100644
> --- a/arch/arm/cpu/ixp/timer.c
> +++ b/arch/arm/cpu/ixp/timer.c
> @@ -1,4 +1,7 @@
>  /*
> + * (C) Copyright 2010
> + * Michael Schwingen, michael at schwingen.org
> + *
>   * (C) Copyright 2006
>   * Stefan Roese, DENX Software Engineering, sr at denx.de.
>   *
> @@ -31,105 +34,94 @@
> 
>  #include <common.h>
>  #include <asm/arch/ixp425.h>
> +#include <asm/io.h>
> +#include <div64.h>
> 
> -#ifdef CONFIG_TIMER_IRQ
> -
> -#define FREQ		66666666
> -#define CLOCK_TICK_RATE	(((FREQ / CONFIG_SYS_HZ & ~IXP425_OST_RELOAD_MASK)
> + 1) * CONFIG_SYS_HZ) -#define LATCH		((CLOCK_TICK_RATE + 
CONFIG_SYS_HZ/2)
> / CONFIG_SYS_HZ)	/* For divider */ +DECLARE_GLOBAL_DATA_PTR;
> 
>  /*
> - * When interrupts are enabled, use timer 2 for time/delay generation...
> + * The IXP42x time-stamp timer runs at 2*OSC_IN (66.666MHz when using a
> + * 33.333MHz crystal).
>   */
> -
> -static volatile ulong timestamp;
> -
> -static void timer_isr(void *data)
> +static inline unsigned long long tick_to_time(unsigned long long tick)
>  {
> -	unsigned int *pTime = (unsigned int *)data;
> -
> -	(*pTime)++;
> -
> -	/*
> -	 * Reset IRQ source
> -	 */
> -	*IXP425_OSST = IXP425_OSST_TIMER_2_PEND;
> +	tick *= CONFIG_SYS_HZ;
> +	do_div(tick, CONFIG_IXP425_TIMER_CLK);
> +	return tick;
>  }
> 
> -ulong get_timer (ulong base)
> +static inline unsigned long long time_to_tick(unsigned long long time)
>  {
> -	return timestamp - base;
> +	time *= CONFIG_IXP425_TIMER_CLK;
> +	do_div(time, CONFIG_SYS_HZ);
> +	return time;
>  }
> 
> -void reset_timer (void)
> +static inline unsigned long long us_to_tick(unsigned long long us)
>  {
> -	timestamp = 0;
> +	us = us * CONFIG_IXP425_TIMER_CLK + 999999;
> +	do_div(us, 1000000);
> +	return us;
>  }
> 
> -int timer_init (void)
> +unsigned long long get_ticks(void)
>  {
> -	/* install interrupt handler for timer */
> -	irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)&timestamp);
> -
> -	/* setup the Timer counter value */
> -	*IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
> +	ulong now = *IXP425_OSTS_B;

Aren't you missing an IO accessor here ?

> +
> +	if (readl(IXP425_OSST) & IXP425_OSST_TIMER_TS_PEND) {
> +		/* rollover of timestamp timer register */
> +		gd->timestamp += (0xFFFFFFFF - gd->lastinc) + now + 1;
> +		writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
> +	} else {
> +		/* move stamp forward with absolut diff ticks */
> +		gd->timestamp += (now - gd->lastinc);
> +	}
> +	gd->lastinc = now;
> +	return gd->timestamp;
> +}
> 
> -	/* enable timer irq */
> -	*IXP425_ICMR = (1 << IXP425_TIMER_2_IRQ);
> 
> -	return 0;
> -}
> -#else
> -ulong get_timer (ulong base)
> +void reset_timer_masked(void)
>  {
> -       return get_timer_masked () - base;
> +	/* capture current timestamp counter */
> +	gd->lastinc = readl(IXP425_OSTS_B);
> +	/* start "advancing" time stamp from 0 */
> +	gd->timestamp = 0;
>  }
> 
> -void ixp425_udelay(unsigned long usec)
> +void reset_timer(void)
>  {
> -	/*
> -	 * This function has a max usec, but since it is called from udelay
> -	 * we should not have to worry... be happy
> -	 */
> -	unsigned long usecs = CONFIG_SYS_HZ/1000000L & ~IXP425_OST_RELOAD_MASK;
> -
> -	*IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
> -	usecs |= IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
> -	*IXP425_OSRT1 = usecs;
> -	while (!(*IXP425_OSST & IXP425_OSST_TIMER_1_PEND));
> +	reset_timer_masked();
>  }
> 
> -void __udelay (unsigned long usec)
> +ulong get_timer_masked(void)
>  {
> -	while (usec--) ixp425_udelay(1);
> +	return tick_to_time(get_ticks());
>  }
> 
> -static ulong reload_constant = 0xfffffff0;
> -
> -void reset_timer_masked (void)
> +ulong get_timer(ulong base)
>  {
> -	ulong reload = reload_constant | IXP425_OST_ONE_SHOT | IXP425_OST_ENABLE;
> +	return get_timer_masked() - base;
> +}
> 
> -	*IXP425_OSST = IXP425_OSST_TIMER_1_PEND;
> -	*IXP425_OSRT1 = reload;
> +void set_timer(ulong t)
> +{
> +	gd->timestamp = time_to_tick(t);
>  }
> 
> -ulong get_timer_masked (void)
> +/* delay x useconds AND preserve advance timestamp value */
> +void __udelay(unsigned long usec)
>  {
> -	/*
> -	 * Note that it is possible for this to wrap!
> -	 * In this case we return max.
> -	 */
> -	ulong current = *IXP425_OST1;
> -	if (*IXP425_OSST & IXP425_OSST_TIMER_1_PEND)
> -	{
> -		return reload_constant;
> -	}
> -	return (reload_constant - current);
> +	unsigned long long tmp;
> +
> +	tmp = get_ticks() + us_to_tick(usec);
> +
> +	while (get_ticks() < tmp)
> +		;
>  }
> 
>  int timer_init(void)
>  {
> +	writel(IXP425_OSST_TIMER_TS_PEND, IXP425_OSST);
>  	return 0;
>  }
> -#endif
> diff --git a/arch/arm/include/asm/arch-ixp/ixp425.h
> b/arch/arm/include/asm/arch-ixp/ixp425.h index 2114437..5132607 100644
> --- a/arch/arm/include/asm/arch-ixp/ixp425.h
> +++ b/arch/arm/include/asm/arch-ixp/ixp425.h
> @@ -391,9 +391,8 @@
>  #define IXP425_TIMER_REG(x) (IXP425_TIMER_BASE_PHYS+(x))
>  #endif
> 
> -#if 0 /* test-only: also defined in npe/include/... */
> -#define IXP425_OSTS	IXP425_TIMER_REG(IXP425_OSTS_OFFSET)
> -#endif
> +/* _B to avoid collision: also defined in npe/include/... */
> +#define IXP425_OSTS_B	IXP425_TIMER_REG(IXP425_OSTS_OFFSET)
>  #define IXP425_OST1	IXP425_TIMER_REG(IXP425_OST1_OFFSET)
>  #define IXP425_OSRT1	IXP425_TIMER_REG(IXP425_OSRT1_OFFSET)
>  #define IXP425_OST2	IXP425_TIMER_REG(IXP425_OST2_OFFSET)

This will eventually enjoy being converted to struct ixp_timer_regset { ... } 
goo. If you already did it in some further patch, sorry, I didn't get there yet 
;-)

> diff --git a/arch/arm/include/asm/global_data.h
> b/arch/arm/include/asm/global_data.h index 2a84d27..c1a59f2 100644
> --- a/arch/arm/include/asm/global_data.h
> +++ b/arch/arm/include/asm/global_data.h
> @@ -64,6 +64,9 @@ typedef	struct	global_data {
>  	unsigned long long	timer_reset_value;
>  	unsigned long	lastinc;
>  #endif
> +#ifdef CONFIG_IXP425
> +	unsigned long	timestamp;
> +#endif
>  	unsigned long	relocaddr;	/* Start address of U-Boot in RAM */
>  	phys_size_t	ram_size;	/* RAM size */
>  	unsigned long	mon_len;	/* monitor len */