Add code for rotary encoder

stm-firmware/include/reflow-controller/rotary-encoder.h

@@ -18,8 +18,25 @@
 * If not, see <http://www.gnu.org/licenses/>.
 */
 
-
 #ifndef __ROTARY_ENCODER_H__
 #define __ROTARY_ENCODER_H__
 
+#include <stm32/stm32f4xx.h>
+
+#define ROTARY_ENCODER_TIMER TIM5
+#define ROTARY_ENCODER_TIMER_RCC_MASK RCC_APB1ENR_TIM5EN
+#define ROTARY_ENCODER_PIN1 0
+#define ROTARY_ENCODER_PIN2 1
+#define ROTARY_ENCODER_PORT GPIOA
+#define ROTARY_ENCODER_PORT_ALTFUNC 2
+#define ROTARY_ENCODER_RCC_MASK RCC_AHB1ENR_GPIOAEN
+
+void rotary_encoder_setup(void);
+
+uint32_t rotary_encoder_get_abs_val(void);
+
+int32_t rotary_encoder_get_chage_val(void);
+
+void rotary_encoder_stop(void);
+
 #endif /* __ROTARY_ENCODER_H__ */