diff --git a/tests/microbit-test.c b/tests/microbit-test.c
index 981a36ed82..0ed64e1962 100644
--- a/tests/microbit-test.c
+++ b/tests/microbit-test.c
@@ -20,6 +20,7 @@
 
 #include "hw/arm/nrf51.h"
 #include "hw/nvram/nrf51_nvm.h"
+#include "hw/gpio/nrf51_gpio.h"
 
 #define FLASH_SIZE          (256 * NRF51_PAGE_SIZE)
 
@@ -100,6 +101,126 @@ static void test_nrf51_nvmc(void)
     }
 }
 
+static void test_nrf51_gpio(void)
+{
+    size_t i;
+    uint32_t actual, expected;
+
+    struct {
+        hwaddr addr;
+        uint32_t expected;
+    } reset_state[] = {
+        {NRF51_GPIO_REG_OUT, 0x00000000}, {NRF51_GPIO_REG_OUTSET, 0x00000000},
+        {NRF51_GPIO_REG_OUTCLR, 0x00000000}, {NRF51_GPIO_REG_IN, 0x00000000},
+        {NRF51_GPIO_REG_DIR, 0x00000000}, {NRF51_GPIO_REG_DIRSET, 0x00000000},
+        {NRF51_GPIO_REG_DIRCLR, 0x00000000}
+    };
+
+    /* Check reset state */
+    for (i = 0; i < ARRAY_SIZE(reset_state); i++) {
+        expected = reset_state[i].expected;
+        actual = readl(NRF51_GPIO_BASE + reset_state[i].addr);
+        g_assert_cmpuint(actual, ==, expected);
+    }
+
+    for (i = 0; i < NRF51_GPIO_PINS; i++) {
+        expected = 0x00000002;
+        actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START + i * 4);
+        g_assert_cmpuint(actual, ==, expected);
+    }
+
+    /* Check dir bit consistency between dir and cnf */
+    /* Check set via DIRSET */
+    expected = 0x80000001;
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIRSET, expected);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIR);
+    g_assert_cmpuint(actual, ==, expected);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_END) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+
+    /* Check clear via DIRCLR */
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIRCLR, 0x80000001);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIR);
+    g_assert_cmpuint(actual, ==, 0x00000000);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_END) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+
+    /* Check set via DIR */
+    expected = 0x80000001;
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIR, expected);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIR);
+    g_assert_cmpuint(actual, ==, expected);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_END) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+
+    /* Reset DIR */
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_DIR, 0x00000000);
+
+    /* Check Input propagates */
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0x00);
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, 0);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, 1);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, -1);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0x02);
+
+    /* Check pull-up working */
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, 0);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b0000);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b1110);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0x02);
+
+    /* Check pull-down working */
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, 1);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b0000);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b0110);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0x02);
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, -1);
+
+    /* Check Output propagates */
+    irq_intercept_out("/machine/nrf51");
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b0011);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_OUTSET, 0x01);
+    g_assert_true(get_irq(0));
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_OUTCLR, 0x01);
+    g_assert_false(get_irq(0));
+
+    /* Check self-stimulation */
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b01);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_OUTSET, 0x01);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x01);
+
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_OUTCLR, 0x01);
+    actual = readl(NRF51_GPIO_BASE + NRF51_GPIO_REG_IN) & 0x01;
+    g_assert_cmpuint(actual, ==, 0x00);
+
+    /* Check short-circuit - generates an guest_error which must be checked
+       manually as long as qtest can not scan qemu_log messages */
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_CNF_START, 0b01);
+    writel(NRF51_GPIO_BASE + NRF51_GPIO_REG_OUTSET, 0x01);
+    set_irq_in("/machine/nrf51", "unnamed-gpio-in", 0, 0);
+}
+
 int main(int argc, char **argv)
 {
     int ret;
@@ -109,6 +230,7 @@ int main(int argc, char **argv)
     global_qtest = qtest_initf("-machine microbit");
 
     qtest_add_func("/microbit/nrf51/nvmc", test_nrf51_nvmc);
+    qtest_add_func("/microbit/nrf51/gpio", test_nrf51_gpio);
 
     ret = g_test_run();
 
