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>

diff --git a/arch/arm/cpu/arm1136/mx35/timer.c b/arch/arm/cpu/arm1136/mx35/timer.c
index 80c0675cfa807bb9e5514335f37902d5bb92f837..04937a1dfeb733ad342b0a1c9821dabf822e7207 100644 (file)
--- 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;
 }