[U-Boot] [PATCH v2 1/2] arm: a320 timer: move static data to global_data struct

Po-Yu Chuang
2010-12-20T09:00:16Z

From: Po-Yu Chuang <ratbert@faraday-tech.com>

timer.c used static data and are called before relocation.
Move all static variables into global_data structure. Also cleanup
timer.c from unused stubs and make it truly use 64 bit tick values.

Based on Reinhard Meyer <u-boot@emk-elektronik.de>'s patch
5dca710a3d7703e41da0e9894f2d71f9e25bea6b

Signed-off-by: Po-Yu Chuang <ratbert@faraday-tech.com>
---
v2:
rebase
use gd->timer_rate_hz.
remove unused global variable timestamp and lastdec.
move register bases to local variables

arch/arm/cpu/arm920t/a320/timer.c | 147 ++++++++++++++-----------------------
1 files changed, 56 insertions(+), 91 deletions(-)

diff --git a/arch/arm/cpu/arm920t/a320/timer.c b/arch/arm/cpu/arm920t/a320/timer.c
index d2e316f..5af94c2 100644
--- a/arch/arm/cpu/arm920t/a320/timer.c
+++ b/arch/arm/cpu/arm920t/a320/timer.c
@@ -18,21 +18,36 @@
*/

#include <common.h>
+#include <div64.h>
#include <asm/io.h>
#include <asm/arch/ftpmu010.h>
#include <asm/arch/fttmr010.h>

-static ulong timestamp;
-static ulong lastdec;
-
-static struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
-static struct ftpmu010 *pmu = (struct ftpmu010 *)CONFIG_FTPMU010_BASE;
+DECLARE_GLOBAL_DATA_PTR;

#define TIMER_CLOCK 32768
#define TIMER_LOAD_VAL 0xffffffff

+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, gd->timer_rate_hz);
+
+ return tick;
+}
+
+static inline unsigned long long usec_to_tick(unsigned long long usec)
+{
+ usec *= gd->timer_rate_hz;
+ do_div(usec, 1000000);
+
+ return usec;
+}
+
int timer_init(void)
{
+ struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+ struct ftpmu010 *pmu = (struct ftpmu010 *)CONFIG_FTPMU010_BASE;
unsigned int oscc;
unsigned int cr;

@@ -76,118 +91,68 @@ int timer_init(void)
cr |= FTTMR010_TM3_ENABLE;
writel(cr, &tmr->cr);

- /* init the timestamp and lastdec value */
- reset_timer_masked();
+ gd->timer_rate_hz = TIMER_CLOCK;
+ gd->tbu = gd->tbl = 0;

return 0;
}

/*
- * timer without interrupts
- */
-
-/*
- * reset time
+ * Get the current 64 bit timer tick count
*/
-void reset_timer_masked(void)
+unsigned long long get_ticks(void)
{
- /* capure current decrementer value time */
- lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
- timestamp = 0; /* start "advancing" time stamp from 0 */
-
- debug("%s(): lastdec = %lx\n", __func__, lastdec);
-}
+ struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+ ulong now = TIMER_LOAD_VAL - readl(&tmr->timer3_counter);

-void reset_timer(void)
-{
debug("%s()\n", __func__);
- reset_timer_masked();
-}

-/*
- * return timer ticks
- */
-ulong get_timer_masked(void)
-{
- /* current tick value */
- ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
-
- debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec);
-
- if (lastdec >= now) {
- /*
- * normal mode (non roll)
- * move stamp fordward with absoulte diff ticks
- */
- timestamp += lastdec - now;
- } 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;
- }
-
- lastdec = now;
-
- debug("%s() returns %lx\n", __func__, timestamp);
-
- return timestamp;
-}
-
-/*
- * return difference between timer ticks and base
- */
-ulong get_timer(ulong base)
-{
- debug("%s(%lx)\n", __func__, base);
- return get_timer_masked() - base;
-}
-
-void set_timer(ulong t)
-{
- debug("%s(%lx)\n", __func__, t);
- timestamp = t;
+ /* increment tbu if tbl has rolled over */
+ if (now < gd->tbl)
+ gd->tbu++;
+ gd->tbl = now;
+ return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
}

/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
- long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
- unsigned long now, last = readl(&tmr->timer3_counter);
-
- debug("%s(%lu)\n", __func__, usec);
- while (tmo > 0) {
- now = readl(&tmr->timer3_counter);
- if (now > last) /* count down timer overflow */
- tmo -= TIMER_LOAD_VAL + last - now;
- else
- tmo -= last - now;
- last = now;
- }
+ unsigned long long tmp;
+ ulong tmo;
+
+ tmo = usec_to_tick(usec);
+ tmp = get_ticks() + tmo; /* get current timestamp */
+
+ while (get_ticks() < tmp) /* loop till event */
+ ;
}

/*
- * This function is derived from PowerPC code (read timebase as long long).
- * On ARM it just returns the timer value.
+ * reset_timer() and get_timer(base) are a pair of functions that are used by
+ * some timeout/sleep mechanisms in u-boot.
+ *
+ * reset_timer() marks the current time as epoch and
+ * get_timer(base) works relative to that epoch.
+ *
+ * The time is used in CONFIG_SYS_HZ units!
*/
-unsigned long long get_ticks(void)
+void reset_timer(void)
{
debug("%s()\n", __func__);
- return get_timer(0);
+ gd->timer_reset_value = get_ticks();
+}
+
+ulong get_timer(ulong base)
+{
+ debug("%s(%lx)\n", __func__, base);
+ return tick_to_time(get_ticks() - gd->timer_reset_value) - base;
}

/*
- * This function is derived from PowerPC code (timebase clock frequency).
- * On ARM it returns the number of timer ticks per second.
+ * Return the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
debug("%s()\n", __func__);
- return CONFIG_SYS_HZ;
+ return gd->timer_rate_hz;
}
--
1.6.3.3