[stm32f429i-discovery] Moved Chucks example to usart_console

Chucks example is more elaborate than the simple ported example so we
keep both.

examples/stm32/f4/stm32f429i-discovery/usart_console/clock.c

@@ -0,0 +1,71 @@
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * Copyright (C) 2013 Chuck McManis <cmcmanis@mcmanis.com>
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Now this is just the clock setup code from systick-blink as it is the
+ * transferrable part.
+ */
+
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/systick.h>
+
+/* Common function descriptions */
+#include "clock.h"
+
+/* milliseconds since boot */
+static volatile uint32_t system_millis;
+
+/* Called when systick fires */
+void sys_tick_handler(void) {
+	system_millis++;
+}
+
+/* simple sleep for delay milliseconds */
+void msleep(uint32_t delay) {
+	uint32_t wake = system_millis + delay;
+	while (wake > system_millis) ;
+}
+
+/* Getter function for the current time */
+uint32_t mtime(void) {
+	return system_millis;
+}
+
+/*
+ * clock_setup(void)
+ *
+ * This function sets up both the base board clock rate
+ * and a 1khz "system tick" count. The SYSTICK counter is
+ * a standard feature of the Cortex-M series.
+ */
+void clock_setup(void)
+{
+	/* Base board frequency, set to 168Mhz */
+	rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);
+
+	/* clock rate / 168000 to get 1mS interrupt rate */
+	systick_set_reload(168000);
+	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB);
+	systick_counter_enable();
+
+	/* this done last */
+	systick_interrupt_enable();
+}