diff --git a/include/libopenstm32/gpio.h b/include/libopenstm32/gpio.h
index a96c999b..8bf8d4b0 100644
--- a/include/libopenstm32/gpio.h
+++ b/include/libopenstm32/gpio.h
@@ -103,6 +103,15 @@
 #define GPIO_TIM1_CH2N			GPIO14		/* PB14 */
 #define GPIO_TIM1_CH3N			GPIO15		/* PB15 */
 
+#define GPIO_TIM1_ETR_REMAP			GPIO7		/* PE7 */
+#define GPIO_TIM1_CH1_REMAP			GPIO9		/* PE9 */
+#define GPIO_TIM1_CH2_REMAP			GPIO11		/* PE11 */
+#define GPIO_TIM1_CH3_REMAP			GPIO13		/* PE13 */
+#define GPIO_TIM1_CH4_REMAP			GPIO14		/* PE14 */
+#define GPIO_TIM1_BKIN_REMAP			GPIO15		/* PE15 */
+#define GPIO_TIM1_CH1N_REMAP			GPIO8		/* PE8 */
+#define GPIO_TIM1_CH2N_REMAP			GPIO10		/* PE10 */
+#define GPIO_TIM1_CH3N_REMAP			GPIO12		/* PE12 */
 /* USART */
 #define GPIO_USART3_TX			GPIO10		/* PB10 */
 #define GPIO_USART3_RX			GPIO11		/* PB11 */
@@ -402,5 +411,6 @@ u16 gpio_get(u32 gpioport, u16 gpios);
 void gpio_toggle(u32 gpioport, u16 gpios);
 u16 gpio_port_read(u32 gpioport);
 void gpio_port_write(u32 gpioport, u16 data);
+void gpio_port_config_lock(u32 gpioport, u16 gpios);
 
 #endif
diff --git a/lib/gpio.c b/lib/gpio.c
index abf47cf3..747977d1 100644
--- a/lib/gpio.c
+++ b/lib/gpio.c
@@ -106,3 +106,17 @@ void gpio_port_write(u32 gpioport, u16 data)
 {
 	GPIO_ODR(gpioport) = data;
 }
+
+void gpio_port_config_lock(u32 gpioport, u16 gpios)
+{
+	u32 reg32;
+
+	/* Special "Lock Key Writing Sequence", see datasheet. */
+	GPIO_LCKR(gpioport) = GPIO_LCKK | gpios;	/* Set LCKK. */
+	GPIO_LCKR(gpioport) = ~GPIO_LCKK & gpios;	/* Clear LCKK. */
+	GPIO_LCKR(gpioport) = GPIO_LCKK | gpios;	/* Set LCKK. */
+	reg32 = GPIO_LCKR(gpioport);			/* Read LCKK. */
+	reg32 = GPIO_LCKR(gpioport);			/* Read LCKK again. */
+	
+	/* If (reg32 & GPIO_LCKK) is true, the lock is now active. */
+}