allow to use different timer clock sources; improve udelay() implementation

diff --git a/arch/arm/cpu/armv7/imx-common/timer.c b/arch/arm/cpu/armv7/imx-common/timer.c
index b304a7d2292764df0ad80cf4e2e470f0651f22d8..6f883eefa347227ab49bd69b03d4d8dca032e5ec 100644 (file)
--- a/arch/arm/cpu/armv7/imx-common/timer.c
+++ b/arch/arm/cpu/armv7/imx-common/timer.c
@@ -42,16 +42,23 @@ static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
 /* General purpose timers bitfields */
 #define GPTCR_SWR              (1 << 15)       /* Software reset */
 #define GPTCR_FRR              (1 << 9)        /* Freerun / restart */
-#define GPTCR_CLKSOURCE_32     (4 << 6)        /* Clock source */
+#define GPTCR_CLKSOURCE_IPG    (1 << 6)        /* Clock source */
+#define GPTCR_CLKSOURCE_CKIH   (2 << 6)
+#define GPTCR_CLKSOURCE_32kHz  (4 << 6)
+#define GPTCR_CLKSOURCE_OSC    (5 << 6)
 #define GPTCR_TEN              1               /* Timer enable */
-#define CLK_32KHZ              32768           /* 32Khz input */
+
+#define GPT_CLKSOURCE          GPTCR_CLKSOURCE_32kHz
+#define GPT_REFCLK             32768
+#define GPT_PRESCALER          1
+#define GPT_CLK                        (GPT_REFCLK / GPT_PRESCALER)
 
 #ifdef DEBUG_TIMER_WRAP
 /*
- * Let the timer wrap 15 seconds after start to catch misbehaving
+ * Let the timer wrap 30 seconds after start to catch misbehaving
  * timer related code early
  */
-#define TIMER_START            (-us_to_tick(10000000))
+#define TIMER_START            (-time_to_tick(30 * CONFIG_SYS_HZ))
 #else
 #define TIMER_START            0UL
 #endif
@@ -60,13 +67,16 @@ DECLARE_GLOBAL_DATA_PTR;
 
 static inline unsigned long tick_to_time(unsigned long tick)
 {
-       return tick * CONFIG_SYS_HZ / CLK_32KHZ;
+       unsigned long long t = (unsigned long long)tick * CONFIG_SYS_HZ;
+       do_div(t, GPT_CLK);
+       return t;
 }
 
 static inline unsigned long time_to_tick(unsigned long time)
 {
        unsigned long long ticks = (unsigned long long)time;
-       ticks *= CLK_32KHZ;
+
+       ticks *= GPT_CLK;
        do_div(ticks, CONFIG_SYS_HZ);
        return ticks;
 }
@@ -74,7 +84,8 @@ static inline unsigned long time_to_tick(unsigned long time)
 static inline unsigned long us_to_tick(unsigned long usec)
 {
        unsigned long long ticks = (unsigned long long)usec;
-       ticks *= CLK_32KHZ;
+
+       ticks *= GPT_CLK;
        do_div(ticks, 1000 * CONFIG_SYS_HZ);
        return ticks;
 }
@@ -91,17 +102,17 @@ int timer_init(void)
        for (i = 0; i < 100; i++)
                __raw_writel(0, &cur_gpt->control);
 
-       __raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
+       __raw_writel(0, &cur_gpt->prescaler);
 
        /* Freerun Mode, PERCLK1 input */
        i = __raw_readl(&cur_gpt->control);
-       __raw_writel(i | GPTCR_CLKSOURCE_32 | GPTCR_TEN, &cur_gpt->control);
+       __raw_writel(i | GPT_CLKSOURCE | GPTCR_TEN, &cur_gpt->control);
 
        val = __raw_readl(&cur_gpt->counter);
-       gd->lastinc = val / (CLK_32KHZ / CONFIG_SYS_HZ);
+       gd->lastinc = val;
        gd->tbu = 0;
        gd->tbl = TIMER_START;
-       gd->timer_rate_hz = CLK_32KHZ;
+       gd->timer_rate_hz = GPT_CLK;
 
        return 0;
 }
@@ -142,14 +153,14 @@ ulong get_timer(ulong base)
 /* delay x useconds AND preserve advance timstamp value */
 void __udelay(unsigned long usec)
 {
-       unsigned long start = get_ticks();      /* get current timestamp */
+       unsigned long start = __raw_readl(&cur_gpt->counter);
        unsigned long ticks = us_to_tick(usec);
 
        if (ticks == 0)
                ticks++;
 
-       while (get_ticks() - start < ticks)     /* loop till event */
-                /*NOP*/;
+       while (__raw_readl(&cur_gpt->counter) - start < ticks)
+               /* loop till event */;
 }
 
 /*