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authorStefano Babic <sbabic@denx.de>2012-02-04 12:56:50 +0100
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2012-02-27 21:19:23 +0100
commit31bb50f815c7684f57b93720dbbbf37da19c62d4 (patch)
tree8665027d7f8a8cebad7ba784cb046b943bbfc35c /arch/arm
parented97abed27455b4f9e0dec6274976f5010258ed9 (diff)
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MX35: add missing get_ticks() and get_tbclk()
commit f31a911fe (arm, post: add missing post_time_ms for arm) enables get_ticks and get_tbclk for all arm based boards, MX5/MX6 have not yet implemented. Signed-off-by: Stefano Babic <sbabic@denx.de>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/cpu/arm1136/mx35/timer.c103
1 files changed, 64 insertions, 39 deletions
diff --git a/arch/arm/cpu/arm1136/mx35/timer.c b/arch/arm/cpu/arm1136/mx35/timer.c
index 80c0675..04937a1 100644
--- a/arch/arm/cpu/arm1136/mx35/timer.c
+++ b/arch/arm/cpu/arm1136/mx35/timer.c
@@ -25,7 +25,14 @@
#include <common.h>
#include <asm/io.h>
+#include <div64.h>
#include <asm/arch/imx-regs.h>
+#include <asm/arch/clock.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define timestamp (gd->tbl)
+#define lastinc (gd->lastinc)
/* General purpose timers bitfields */
#define GPTCR_SWR (1<<15) /* Software reset */
@@ -33,7 +40,24 @@
#define GPTCR_CLKSOURCE_32 (0x100<<6) /* Clock source */
#define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */
#define GPTCR_TEN (1) /* Timer enable */
-#define GPTPR_VAL (66)
+
+#define TIMER_FREQ_HZ mxc_get_clock(MXC_IPG_CLK)
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, TIMER_FREQ_HZ);
+
+ return tick;
+}
+
+static inline unsigned long long us_to_tick(unsigned long long usec)
+{
+ usec *= TIMER_FREQ_HZ;
+ do_div(usec, 1000000);
+
+ return usec;
+}
int timer_init(void)
{
@@ -45,7 +69,7 @@ int timer_init(void)
for (i = 0; i < 100; i++)
writel(0, &gpt->ctrl); /* We have no udelay by now */
- writel(GPTPR_VAL, &gpt->pre);
+ writel(0, &gpt->pre);
/* Freerun Mode, PERCLK1 input */
writel(readl(&gpt->ctrl) |
GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
@@ -54,58 +78,59 @@ int timer_init(void)
return 0;
}
-void reset_timer_masked(void)
+unsigned long long get_ticks(void)
{
struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
-
- writel(0, &gpt->ctrl);
- /* Freerun Mode, PERCLK1 input */
- writel(GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
- &gpt->ctrl);
+ ulong now = readl(&gpt->counter); /* current tick value */
+
+ if (now >= lastinc) {
+ /*
+ * normal mode (non roll)
+ * move stamp forward with absolut diff ticks
+ */
+ timestamp += (now - lastinc);
+ } else {
+ /* we have rollover of incrementer */
+ timestamp += (0xFFFFFFFF - lastinc) + now;
+ }
+ lastinc = now;
+ return timestamp;
}
-inline ulong get_timer_masked(void)
+ulong get_timer_masked(void)
{
-
- struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
- ulong val = readl(&gpt->counter);
-
- return val;
+ /*
+ * get_ticks() returns a long long (64 bit), it wraps in
+ * 2^64 / CONFIG_MX25_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
+ * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
+ * 5 * 10^6 days - long enough.
+ */
+ return tick_to_time(get_ticks());
}
ulong get_timer(ulong base)
{
- ulong tmp;
+ return get_timer_masked() - base;
+}
- tmp = get_timer_masked();
+/* delay x useconds AND preserve advance timstamp value */
+void __udelay(unsigned long usec)
+{
+ unsigned long long tmp;
+ ulong tmo;
- if (tmp <= (base * 1000)) {
- /* Overflow */
- tmp += (0xffffffff - base);
- }
+ tmo = us_to_tick(usec);
+ tmp = get_ticks() + tmo; /* get current timestamp */
- return (tmp / 1000) - base;
+ while (get_ticks() < tmp) /* loop till event */
+ /*NOP*/;
}
/*
- * delay x useconds AND preserve advance timstamp value
- * GPTCNT is now supposed to tick 1 by 1 us.
+ * This function is derived from PowerPC code (timebase clock frequency).
+ * On ARM it returns the number of timer ticks per second.
*/
-void __udelay(unsigned long usec)
+ulong get_tbclk(void)
{
- ulong tmp;
-
- tmp = get_timer_masked(); /* get current timestamp */
-
- /* if setting this forward will roll time stamp */
- if ((usec + tmp + 1) < tmp) {
- /* reset "advancing" timestamp to 0, set lastinc value */
- reset_timer_masked();
- } else {
- /* else, set advancing stamp wake up time */
- tmp += usec;
- }
-
- while (get_timer_masked() < tmp) /* loop till event */
- /*NOP*/;
+ return TIMER_FREQ_HZ;
}