Merge branch 'u-boot/master' into 'u-boot-arm/master'

[karo-tx-uboot.git] / arch / arm / cpu / armv7 / s5p-common / timer.c

diff --git a/arch/arm/cpu/armv7/s5p-common/timer.c b/arch/arm/cpu/armv7/s5p-common/timer.c
index 0b69f0678cf0c0be214b840527278832806a85ea..6a0fa5862ec0782130f2bd712aa2bb156b101c56 100644 (file)
--- a/arch/arm/cpu/armv7/s5p-common/timer.c
+++ b/arch/arm/cpu/armv7/s5p-common/timer.c
@@ -31,74 +31,88 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+unsigned long get_current_tick(void);
+
 /* macro to read the 16 bit timer */
 static inline struct s5p_timer *s5p_get_base_timer(void)
 {
        return (struct s5p_timer *)samsung_get_base_timer();
 }
 
+/**
+ * Read the countdown timer.
+ *
+ * This operates at 1MHz and counts downwards. It will wrap about every
+ * hour (2^32 microseconds).
+ *
+ * @return current value of timer
+ */
+static unsigned long timer_get_us_down(void)
+{
+       struct s5p_timer *const timer = s5p_get_base_timer();
+
+       return readl(&timer->tcnto4);
+}
+
 int timer_init(void)
 {
        /* PWM Timer 4 */
-       pwm_init(4, MUX_DIV_2, 0);
-       pwm_config(4, 0, 0);
+       pwm_init(4, MUX_DIV_4, 0);
+       pwm_config(4, 100000, 100000);
        pwm_enable(4);
 
+       /* Use this as the current monotonic time in us */
+       gd->arch.timer_reset_value = 0;
+
+       /* Use this as the last timer value we saw */
+       gd->arch.lastinc = timer_get_us_down();
+       reset_timer_masked();
+
        return 0;
 }
 
 /*
  * timer without interrupts
  */
-void reset_timer(void)
+unsigned long get_timer(unsigned long base)
 {
-       reset_timer_masked();
+       ulong now = timer_get_us_down();
+
+       /*
+        * Increment the time by the amount elapsed since the last read.
+        * The timer may have wrapped around, but it makes no difference to
+        * our arithmetic here.
+        */
+       gd->arch.timer_reset_value += gd->arch.lastinc - now;
+       gd->arch.lastinc = now;
+
+       /* Divide by 1000 to convert from us to ms */
+       return gd->arch.timer_reset_value / 1000 - base;
 }
 
-unsigned long get_timer(unsigned long base)
+unsigned long timer_get_us(void)
 {
-       return get_timer_masked() - base;
+       static unsigned long base_time_us;
+
+       struct s5p_timer *const timer =
+               (struct s5p_timer *)samsung_get_base_timer();
+       unsigned long now_downward_us = readl(&timer->tcnto4);
+
+       if (!base_time_us)
+               base_time_us = now_downward_us;
+
+       /* Note that this timer counts downward. */
+       return base_time_us - now_downward_us;
 }
 
 /* delay x useconds */
 void __udelay(unsigned long usec)
 {
-       struct s5p_timer *const timer = s5p_get_base_timer();
-       unsigned long tmo, tmp, count_value;
-
-       count_value = readl(&timer->tcntb4);
-
-       if (usec >= 1000) {
-               /*
-                * if "big" number, spread normalization
-                * to seconds
-                * 1. start to normalize for usec to ticks per sec
-                * 2. find number of "ticks" to wait to achieve target
-                * 3. finish normalize.
-                */
-               tmo = usec / 1000;
-               tmo *= (CONFIG_SYS_HZ * count_value / 10);
-               tmo /= 1000;
-       } else {
-               /* else small number, don't kill it prior to HZ multiply */
-               tmo = usec * CONFIG_SYS_HZ * count_value / 10;
-               tmo /= (1000 * 1000);
-       }
-
-       /* get current timestamp */
-       tmp = get_timer(0);
-
-       /* if setting this fordward will roll time stamp */
-       /* reset "advancing" timestamp to 0, set lastinc value */
-       /* else, set advancing stamp wake up time */
-       if ((tmo + tmp + 1) < tmp)
-               reset_timer_masked();
-       else
-               tmo += tmp;
-
-       /* loop till event */
-       while (get_timer_masked() < tmo)
-               ;       /* nop */
+       unsigned long count_value;
+
+       count_value = timer_get_us_down();
+       while ((int)(count_value - timer_get_us_down()) < (int)usec)
+               ;
 }
 
 void reset_timer_masked(void)
@@ -106,24 +120,8 @@ void reset_timer_masked(void)
        struct s5p_timer *const timer = s5p_get_base_timer();
 
        /* reset time */
-       gd->lastinc = readl(&timer->tcnto4);
-       gd->tbl = 0;
-}
-
-unsigned long get_timer_masked(void)
-{
-       struct s5p_timer *const timer = s5p_get_base_timer();
-       unsigned long now = readl(&timer->tcnto4);
-       unsigned long count_value = readl(&timer->tcntb4);
-
-       if (gd->lastinc >= now)
-               gd->tbl += gd->lastinc - now;
-       else
-               gd->tbl += gd->lastinc + count_value - now;
-
-       gd->lastinc = now;
-
-       return gd->tbl;
+       gd->arch.lastinc = readl(&timer->tcnto4);
+       gd->arch.tbl = 0;
 }
 
 /*