altos/lpc: Add boot loader

Support the USB boot loader, add USB pull-up support.

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

1 files changed, 46 insertions, 0 deletions

diff --git a/src/lpc/ao_boot_pin.c b/src/lpc/ao_boot_pin.c
new file mode 100644
index 00000000..51ecc0a9
--- /dev/null
+++ b/src/lpc/ao_boot_pin.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright © 2013 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.
+ */
+
+#include <ao.h>
+#include <ao_boot.h>
+#include <ao_exti.h>
+
+void
+ao_boot_check_pin(void)
+{
+	uint16_t v;
+
+	/* Enable power interface clock */
+//	stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
+	
+	/* Enable the input pin */
+	ao_enable_input(AO_BOOT_APPLICATION_GPIO, AO_BOOT_APPLICATION_PIN,
+			AO_BOOT_APPLICATION_MODE);
+
+	for (v = 0; v < 100; v++)
+		ao_arch_nop();
+
+	/* Read the value */
+	v = ao_gpio_get(AO_BOOT_APPLICATION_GPIO, AO_BOOT_APPLICATION_PIN, AO_BOOT_APPLICATION);
+
+	/* Reset the chip to turn off the port and the power interface clock */
+	ao_gpio_set_mode(AO_BOOT_APPLICATION_GPIO, AO_BOOT_APPLICATION_PIN, 0);
+	ao_disable_port(AO_BOOT_APPLICATION_GPIO);
+//	stm_rcc.apb1enr &= ~(1 << STM_RCC_APB1ENR_PWREN);
+	if (v == AO_BOOT_APPLICATION_VALUE)
+		ao_boot_chain(AO_BOOT_APPLICATION_BASE);
+}