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>

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>
Rob Herring · Tom Rini · Eric Lee · Eric Lee · Eric Lee · Eric Lee
1 parent e32a268b6f
Showing 2 changed files with 75 additions and 0 deletions Side-by-side Diff
include/asm-generic/global_data.h
lib/time.c
@@ -72,6 +72,8 @@
 #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
@@ -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"
@@ -15,6 +17,77 @@
 #ifndef CONFIG_WD_PERIOD
 # 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*/;
+}
  
 /* ------------------------------------------------------------------------- */
...	...	@@ -72,6 +72,8 @@
72	72	#if defined(CONFIG_SYS_I2C)
73	73	int cur_i2c_bus; /* current used i2c bus */
74	74	#endif
	75	+ unsigned long timebase_h;
	76	+ unsigned long timebase_l;
75	77	struct arch_global_data arch; /* architecture-specific data */
76	78	} gd_t;
77	79	#endif
...	...	@@ -7,6 +7,8 @@
7	7
8	8	#include <common.h>
9	9	#include <watchdog.h>
	10	+#include <div64.h>
	11	+#include <asm/io.h>
10	12
11	13	#if CONFIG_SYS_HZ != 1000
12	14	#warning "CONFIG_SYS_HZ must be 1000 and should not be defined by platforms"
...	...	@@ -15,6 +17,77 @@
15	17	#ifndef CONFIG_WD_PERIOD
16	18	# define CONFIG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default*/
17	19	#endif
	20	+
	21	+DECLARE_GLOBAL_DATA_PTR;
	22	+
	23	+#ifdef CONFIG_SYS_TIMER_RATE
	24	+ulong notrace get_tbclk(void)
	25	+{
	26	+ return CONFIG_SYS_TIMER_RATE;
	27	+}
	28	+#endif
	29	+
	30	+#ifdef CONFIG_SYS_TIMER_COUNTER
	31	+unsigned long notrace timer_read_counter(void)
	32	+{
	33	+#ifdef CONFIG_SYS_TIMER_COUNTS_DOWN
	34	+ return ~readl(CONFIG_SYS_TIMER_COUNTER);
	35	+#else
	36	+ return readl(CONFIG_SYS_TIMER_COUNTER);
	37	+#endif
	38	+}
	39	+#else
	40	+extern unsigned long timer_read_counter(void);
	41	+#endif
	42	+
	43	+unsigned long long __weak notrace get_ticks(void)
	44	+{
	45	+ unsigned long now = timer_read_counter();
	46	+
	47	+ /* increment tbu if tbl has rolled over */
	48	+ if (now < gd->timebase_l)
	49	+ gd->timebase_h++;
	50	+ gd->timebase_l = now;
	51	+ return ((unsigned long long)gd->timebase_h << 32) \| gd->timebase_l;
	52	+}
	53	+
	54	+static unsigned long long notrace tick_to_time(unsigned long long tick)
	55	+{
	56	+ unsigned int div = get_tbclk();
	57	+
	58	+ tick *= CONFIG_SYS_HZ;
	59	+ do_div(tick, div);
	60	+ return tick;
	61	+}
	62	+
	63	+ulong __weak get_timer(ulong base)
	64	+{
	65	+ return tick_to_time(get_ticks()) - base;
	66	+}
	67	+
	68	+unsigned long __weak notrace timer_get_us(void)
	69	+{
	70	+ return tick_to_time(get_ticks() * 1000);
	71	+}
	72	+static unsigned long long usec_to_tick(unsigned long usec)
	73	+{
	74	+ unsigned long long tick = usec * get_tbclk();
	75	+ usec *= get_tbclk();
	76	+ do_div(tick, 1000000);
	77	+ return tick;
	78	+}
	79	+
	80	+void __weak __udelay(unsigned long usec)
	81	+{
	82	+ unsigned long long tmp;
	83	+ ulong tmo;
	84	+
	85	+ tmo = usec_to_tick(usec);
	86	+ tmp = get_ticks() + tmo; /* get current timestamp */
	87	+
	88	+ while (get_ticks() < tmp) /* loop till event */
	89	+ /NOP/;
	90	+}
18	91
19	92	/* ------------------------------------------------------------------------- */
20	93