bootstage: Define an optional microsecond timer

Define timer_get_boot_us() which returns the number of microseconds since boot. If undefined then we use get_timer() * 1000. We can fit this in a 32-bit register which keeps everyone happy on the efficiency side. It will wrap around after about an hour. If we are still looking at it after an hour then we had better not be timing the boot. Signed-off-by: Simon Glass <sjg@chromium.org>

bootstage: Define an optional microsecond timer
Define timer_get_boot_us() which returns the number of microseconds since boot. If undefined then we use get_timer() * 1000. We can fit this in a 32-bit register which keeps everyone happy on the efficiency side. It will wrap around after about an hour. If we are still looking at it after an hour then we had better not be timing the boot. Signed-off-by: Simon Glass <sjg@chromium.org>
Simon Glass · Wolfgang Denk
1 parent aacc8c16ee
Showing 2 changed files with 24 additions and 0 deletions Side-by-side Diff
include/common.h
lib/time.c
@@ -207,6 +207,13 @@
 #endif /* CONFIG_SERIAL_MULTI */
  
 /*
+ * Return the time since boot in microseconds, This is needed for bootstage
+ * and should be defined in CPU- or board-specific code. If undefined then
+ * millisecond resolution will be used (the standard get_timer()).
+ */
+ulong timer_get_boot_us(void);
+
+/*
  * General Purpose Utilities
  */
 #define min(X, Y)				\
@@ -47,4 +47,21 @@
 	while (msec--)
 		udelay(1000);
 }
+
+ulong __timer_get_boot_us(void)
+{
+	static ulong base_time;
+
+	/*
+	 * We can't implement this properly. Return 0 on the first call and
+	 * larger values after that.
+	 */
+	if (base_time)
+		return get_timer(base_time) * 1000;
+	base_time = get_timer(0);
+	return 0;
+}
+
+ulong timer_get_boot_us(void)
+	__attribute__((weak, alias("__timer_get_boot_us")));
...	...	@@ -207,6 +207,13 @@
207	207	#endif /* CONFIG_SERIAL_MULTI */
208	208
209	209	/*
	210	+ * Return the time since boot in microseconds, This is needed for bootstage
	211	+ * and should be defined in CPU- or board-specific code. If undefined then
	212	+ * millisecond resolution will be used (the standard get_timer()).
	213	+ */
	214	+ulong timer_get_boot_us(void);
	215	+
	216	+/*
210	217	* General Purpose Utilities
211	218	*/
212	219	#define min(X, Y) \
...	...	@@ -47,4 +47,21 @@
47	47	while (msec--)
48	48	udelay(1000);
49	49	}
	50	+
	51	+ulong __timer_get_boot_us(void)
	52	+{
	53	+ static ulong base_time;
	54	+
	55	+ /*
	56	+ * We can't implement this properly. Return 0 on the first call and
	57	+ * larger values after that.
	58	+ */
	59	+ if (base_time)
	60	+ return get_timer(base_time) * 1000;
	61	+ base_time = get_timer(0);
	62	+ return 0;
	63	+}
	64	+
	65	+ulong timer_get_boot_us(void)
	66	+ __attribute__((weak, alias("__timer_get_boot_us")));