altos: Create a 32-bit 1MHz timer for use in profiling execution

This provides a simple method for getting high-resolution timer data
to use in performance tuning code. It's not used by default anywhere.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/stm/ao_profile.h b/src/stm/ao_profile.h
new file mode 100644
index 00000000..f7dd029d
--- /dev/null
+++ b/src/stm/ao_profile.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_PROFILE_H_
+#define _AO_PROFILE_H_
+
+void	ao_profile_init();
+
+static uint32_t inline ao_profile_tick(void) {
+	uint16_t	hi, lo, second_hi;
+
+	do {
+		hi = stm_tim2.cnt;
+		lo = stm_tim4.cnt;
+		second_hi = stm_tim2.cnt;
+	} while (hi != second_hi);
+	return ((uint32_t) hi << 16) | lo;
+}
+
+#endif