pwm: add config_ms and config_percent.

* Allows user to set both at the same time. Will reset to previous if
* period for duty cycle fails to write

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>

api/mraa/pwm.h

@@ -166,6 +166,26 @@ mraa_result_t mraa_pwm_owner(mraa_pwm_context dev, mraa_boolean_t owner);
  */
 mraa_result_t mraa_pwm_close(mraa_pwm_context dev);
 
+/**
+ * Set Both Period and DutyCycle on a PWM context
+ *
+ * @param dev The pwm context to use
+ * @param period represented in ms.
+ * @param duty dutycycle of the pwm signal.
+ * @return Result of operation
+ */
+mraa_result_t mraa_pwm_config_ms(mraa_pwm_context dev, int period, float duty);
+
+/**
+ * Set Both Period and DutyCycle on a PWM context. Duty represented as percentage.
+ *
+ * @param dev The pwm context to use
+ * @param period represented in ms.
+ * @param duty duty percantage. i.e. 50% = 0.5f
+ * @return Result of operation
+ */
+mraa_result_t mraa_pwm_config_percent(mraa_pwm_context dev, int period, float duty);
+
 #ifdef __cplusplus
 }
 #endif

api/mraa/pwm.hpp

@@ -150,6 +150,27 @@ class Pwm {
             else
                 return mraa_pwm_enable(m_pwm, 0);
         }
+        /**
+         * Set the period and duty of a PWM object.
+         *
+         * @param period represented in ms.
+         * @param duty represnted in ms as float.
+         * @return Result of operation
+         */
+        mraa_result_t config_ms(int period, float duty) {
+            return mraa_pwm_config_ms(m_pwm, period, duty);
+        }
+        /**
+         * Set the period and duty (percent) of a PWM object.
+         *
+         * @param period as represented in ms.
+         * @param duty percentage i.e. 50% = 0.5f
+         * @return Result of operation
+         */
+        mraa_result_t config_percent(int period, float duty) {
+            return mraa_pwm_config_percent(m_pwm, period, duty);
+        }
+
     private:
         mraa_pwm_context m_pwm;
 };