#include <asm/io.h>
#include <asm/arch/pwm.h>
#include <asm/arch/clk.h>
+#include <pwm.h>
-#define PRESCALER_1 (16 - 1) /* prescaler of timer 2, 3, 4 */
-#define MUX_DIV_2 1 /* 1/2 period */
-#define MUX_DIV_4 2 /* 1/4 period */
-#define MUX_DIV_8 3 /* 1/8 period */
-#define MUX_DIV_16 4 /* 1/16 period */
-#define MUX4_DIV_SHIFT 16
+DECLARE_GLOBAL_DATA_PTR;
-#define TCON_TIMER4_SHIFT 20
-
-static unsigned long count_value;
-
-/* Internal tick units */
-static unsigned long long timestamp; /* Monotonic incrementing timer */
-static unsigned long lastdec; /* Last decremneter snapshot */
+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();
}
-int timer_init(void)
+/**
+ * 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();
- u32 val;
-
- /*
- * @ PWM Timer 4
- * Timer Freq(HZ) =
- * PWM_CLK / { (prescaler_value + 1) * (divider_value) }
- */
-
- /* set prescaler : 16 */
- /* set divider : 2 */
- writel((PRESCALER_1 & 0xff) << 8, &timer->tcfg0);
- writel((MUX_DIV_2 & 0xf) << MUX4_DIV_SHIFT, &timer->tcfg1);
- /* count_value = 2085937.5(HZ) (per 1 sec)*/
- count_value = get_pwm_clk() / ((PRESCALER_1 + 1) *
- (MUX_DIV_2 + 1));
-
- /* count_value / 100 = 20859.375(HZ) (per 10 msec) */
- count_value = count_value / 100;
-
- /* set count value */
- writel(count_value, &timer->tcntb4);
- lastdec = count_value;
-
- val = (readl(&timer->tcon) & ~(0x07 << TCON_TIMER4_SHIFT)) |
- TCON4_AUTO_RELOAD;
+ return readl(&timer->tcnto4);
+}
- /* auto reload & manual update */
- writel(val | TCON4_UPDATE, &timer->tcon);
+int timer_init(void)
+{
+ /* PWM Timer 4 */
+ pwm_init(4, MUX_DIV_4, 0);
+ pwm_config(4, 0, 0);
+ pwm_enable(4);
- /* start PWM timer 4 */
- writel(val | TCON4_START, &timer->tcon);
+ /* Use this as the current monotonic time in us */
+ gd->arch.timer_reset_value = 0;
- timestamp = 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)
-{
- reset_timer_masked();
-}
-
unsigned long get_timer(unsigned long base)
{
- return get_timer_masked() - base;
+ 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;
}
-void set_timer(unsigned long t)
+unsigned long timer_get_us(void)
{
- timestamp = t;
+ 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 = 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 lastdec 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)
struct s5p_timer *const timer = s5p_get_base_timer();
/* reset time */
- lastdec = readl(&timer->tcnto4);
- timestamp = 0;
-}
-
-unsigned long get_timer_masked(void)
-{
- struct s5p_timer *const timer = s5p_get_base_timer();
- unsigned long now = readl(&timer->tcnto4);
-
- if (lastdec >= now)
- timestamp += lastdec - now;
- else
- timestamp += lastdec + count_value - now;
-
- lastdec = now;
-
- return timestamp;
+ gd->arch.lastinc = readl(&timer->tcnto4);
+ gd->arch.tbl = 0;
}
/*
projects / karo-tx-uboot.git / blobdiff