Introduce common timer functions

Many platforms duplicate pretty much the same timer code yet they all have
a 32-bit freerunning counter register. Create a common implementation that
minimally requires 2 or 3 defines to add timer support:

CONFIG_SYS_TIMER_RATE - Clock rate of the timer counter
CONFIG_SYS_TIMER_COUNTER - Address of 32-bit counter
CONFIG_SYS_TIMER_COUNTS_DOWN - Define if counter counts down

All functions are weak or ifdef'ed so they can still be overriden by any
platform.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>

diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 77e06fb4fefc045226f286c5985e2fb8685eaea3..0de0beaa8bd9929e9d7b2e349e96bc44afe042e6 100644 (file)
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -72,6 +72,8 @@ typedef struct global_data {
 #if defined(CONFIG_SYS_I2C)
        int             cur_i2c_bus;    /* current used i2c bus */
 #endif
+       unsigned long timebase_h;
+       unsigned long timebase_l;
        struct arch_global_data arch;   /* architecture-specific data */
 } gd_t;
 #endif

diff --git a/lib/time.c b/lib/time.c
index 6514835df7832a2bb48eb2690ae3657100aef748..8361ddd69b648e1874a8e41302717da7202cef7a 100644 (file)
--- a/lib/time.c
+++ b/lib/time.c
@@ -7,6 +7,8 @@
 
 #include <common.h>
 #include <watchdog.h>
+#include <div64.h>
+#include <asm/io.h>
 
 #if CONFIG_SYS_HZ != 1000
 #warning "CONFIG_SYS_HZ must be 1000 and should not be defined by platforms"
@@ -16,6 +18,77 @@
 # define CONFIG_WD_PERIOD      (10 * 1000 * 1000)      /* 10 seconds default*/
 #endif
 
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifdef CONFIG_SYS_TIMER_RATE
+ulong notrace get_tbclk(void)
+{
+       return CONFIG_SYS_TIMER_RATE;
+}
+#endif
+
+#ifdef CONFIG_SYS_TIMER_COUNTER
+unsigned long notrace timer_read_counter(void)
+{
+#ifdef CONFIG_SYS_TIMER_COUNTS_DOWN
+       return ~readl(CONFIG_SYS_TIMER_COUNTER);
+#else
+       return readl(CONFIG_SYS_TIMER_COUNTER);
+#endif
+}
+#else
+extern unsigned long timer_read_counter(void);
+#endif
+
+unsigned long long __weak notrace get_ticks(void)
+{
+       unsigned long now = timer_read_counter();
+
+       /* increment tbu if tbl has rolled over */
+       if (now < gd->timebase_l)
+               gd->timebase_h++;
+       gd->timebase_l = now;
+       return ((unsigned long long)gd->timebase_h << 32) | gd->timebase_l;
+}
+
+static unsigned long long notrace tick_to_time(unsigned long long tick)
+{
+       unsigned int div = get_tbclk();
+
+       tick *= CONFIG_SYS_HZ;
+       do_div(tick, div);
+       return tick;
+}
+
+ulong __weak get_timer(ulong base)
+{
+       return tick_to_time(get_ticks()) - base;
+}
+
+unsigned long __weak notrace timer_get_us(void)
+{
+       return tick_to_time(get_ticks() * 1000);
+}
+static unsigned long long usec_to_tick(unsigned long usec)
+{
+       unsigned long long tick = usec * get_tbclk();
+       usec *= get_tbclk();
+       do_div(tick, 1000000);
+       return tick;
+}
+
+void __weak __udelay(unsigned long usec)
+{
+       unsigned long long tmp;
+       ulong tmo;
+
+       tmo = usec_to_tick(usec);
+       tmp = get_ticks() + tmo;        /* get current timestamp */
+
+       while (get_ticks() < tmp)       /* loop till event */
+                /*NOP*/;
+}
+
 /* ------------------------------------------------------------------------- */
 
 void udelay(unsigned long usec)