[U-Boot] [PATCH 04/13] Fix IXP code to work after relocation was added: - jump to real flash location after reset before turning off flash mirror - fix timer system to use HZ == 1000, remove broken interrupt-based code

Michael Schwingen
2010-12-28T12:43:22Z

arch/arm/cpu/ixp/cpu.c | 5 --
arch/arm/cpu/ixp/start.S | 59 ++--------------
arch/arm/cpu/ixp/timer.c | 125 +++++++++++++++-----------------
arch/arm/include/asm/arch-ixp/ixp425.h | 5 +-
4 files changed, 66 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 9f8c15b..2c49aa4 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
@@ -163,12 +165,6 @@ 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]
@@ -212,19 +208,6 @@ 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
@@ -237,19 +220,12 @@ 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
@@ -265,7 +241,7 @@ 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 */
@@ -578,28 +554,3 @@ 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..54a7a55 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@denx.de.
*
@@ -31,105 +34,95 @@

#include <common.h>
#include <asm/arch/ixp425.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 */
+#include <div64.h>

/*
- * 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)
+static ulong timestamp;
+static ulong lastinc;
+
+unsigned long long get_ticks (void)
{
- /* install interrupt handler for timer */
- irq_install_handler(IXP425_TIMER_2_IRQ, timer_isr, (void *)&timestamp);
+ ulong now = *IXP425_OSTS_B;

- /* setup the Timer counter value */
- *IXP425_OSRT2 = (LATCH & ~IXP425_OST_RELOAD_MASK) | IXP425_OST_ENABLE;
+ if (*IXP425_OSST & IXP425_OSST_TIMER_TS_PEND) {
+ /* rollover of timestamp timer register */
+ timestamp += (0xFFFFFFFF - lastinc) + now + 1;
+ *IXP425_OSST = IXP425_OSST_TIMER_TS_PEND;
+ }
+ else {
+ /* move stamp forward with absolut diff ticks */
+ timestamp += (now - lastinc);
+ }
+ lastinc = now;
+ return 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;
+ /* reset time */
+ lastinc = *IXP425_OSTS_B; /* capture current timestamp counter */
+ timestamp = 0; /* start "advancing" time stamp from 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)
+{
+ 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)
{
+ *IXP425_OSST = IXP425_OSST_TIMER_TS_PEND;
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..ddbf713 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)
--
1.7.2.3