lpc176x: Add initial support for LPC176x processors

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/lpc176x/gpio.c b/src/lpc176x/gpio.c
new file mode 100644
index 00000000..756b0e7b
--- /dev/null
+++ b/src/lpc176x/gpio.c
@@ -0,0 +1,28 @@
+// GPIO functions on lpc176x
+//
+// Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "LPC17xx.h" // LPC_PINCON
+#include "internal.h" // gpio_peripheral
+#include "board/irq.h" // irq_save
+
+// Set the mode and extended function of a pin
+void
+gpio_peripheral(int bank, int pin, int func, int pullup)
+{
+    uint32_t bank_pos = bank * 2, pin_pos = pin * 2;
+    if (pin_pos >= 32) {
+        pin_pos -= 32;
+        bank_pos++;
+    }
+    uint32_t sel_bits = (func & 0x03) << pin_pos, mask = ~(0x03 << pin_pos);
+    uint32_t mode_bits = (pullup ? 0x00 : 0x02) << pin_pos;
+    volatile uint32_t *pinsel = &LPC_PINCON->PINSEL0;
+    volatile uint32_t *pinmode = &LPC_PINCON->PINMODE0;
+    irqstatus_t flag = irq_save();
+    pinsel[bank_pos] = (pinsel[bank_pos] & mask) | sel_bits;
+    pinmode[bank_pos] = (pinmode[bank_pos] & mask) | mode_bits;
+    irq_restore(flag);
+}