drivers/led: add LED_NUMOF and convenience inline functions

drivers/include/led.h

@@ -9,7 +9,7 @@
 /**
  * @defgroup    drivers_led Control on-board LEDs
  * @ingroup     drivers_actuators
- * @brief       Access macros to control the on-board LEDs
+ * @brief       Access macros and functions to control the on-board LEDs
  *
  * This header contains a set of macros for controlling the on-board LEDs of
  * a board. The LEDs are enumerated, starting from LED0 to LED7. As most
@@ -24,7 +24,7 @@
  * @{
  *
  * @file
- * @brief       Macros for controlling the on-board LEDs
+ * @brief       Macros and inline functions for controlling the on-board LEDs
  *
  * @author      Hauke Petersen <[email protected]>
  */
@@ -106,15 +106,102 @@ extern "C" {
 #define LED7_IS_PRESENT     /**< indicate that LED7 is present */
 #endif
 
+/**
+ * Number of LEDs available on the current board.
+ */
+#if defined(LED7_IS_PRESENT)
+#define LED_NUMOF 8
+#elif defined(LED6_IS_PRESENT)
+#define LED_NUMOF 7
+#elif defined(LED5_IS_PRESENT)
+#define LED_NUMOF 6
+#elif defined(LED4_IS_PRESENT)
+#define LED_NUMOF 5
+#elif defined(LED3_IS_PRESENT)
+#define LED_NUMOF 4
+#elif defined(LED2_IS_PRESENT)
+#define LED_NUMOF 3
+#elif defined(LED1_IS_PRESENT)
+#define LED_NUMOF 2
+#elif defined(LED0_IS_PRESENT)
+#define LED_NUMOF 1
+#else
+#define LED_NUMOF 0
+#endif
+
 /** @} */
 
 /**
- * @name    Convenience LED control macros
+ * @name    Convenience LED control functions and macros
  * @{
  */
-#define LED_ON(x)           LED ## x ##_ON      /**< Turn on led x */
-#define LED_OFF(x)          LED ## x ## _OFF    /**< Turn off led x */
-#define LED_TOGGLE(x)       LED ## x ##_TOGGLE  /**< Toggle led x */
+#define LED_ON(id)           LED ## id ##_ON      /**< Turn on an LED */
+#define LED_OFF(id)          LED ## id ## _OFF    /**< Turn off an LED */
+#define LED_TOGGLE(id)       LED ## id ##_TOGGLE  /**< Toggle an LED */
+
+/**
+ * Turn on an LED.
+ *
+ * @note If id is a compile-time constant, consider using @ref LED_ON(id) instead.
+ *
+ * @param id    id of LED between 0 and 7
+ */
+static inline void led_on(unsigned id)
+{
+    switch (id) {
+        case 0: LED0_ON; break;
+        case 1: LED1_ON; break;
+        case 2: LED2_ON; break;
+        case 3: LED3_ON; break;
+        case 4: LED4_ON; break;
+        case 5: LED5_ON; break;
+        case 6: LED6_ON; break;
+        case 7: LED7_ON; break;
+    }
+}
+
+/**
+ * Turn off an LED.
+ *
+ * @note If id is a compile-time constant, consider using @ref LED_OFF(id) instead.
+ *
+ * @param id    id of LED between 0 and 7
+ */
+static inline void led_off(unsigned id)
+{
+    switch (id) {
+        case 0: LED0_OFF; break;
+        case 1: LED1_OFF; break;
+        case 2: LED2_OFF; break;
+        case 3: LED3_OFF; break;
+        case 4: LED4_OFF; break;
+        case 5: LED5_OFF; break;
+        case 6: LED6_OFF; break;
+        case 7: LED7_OFF; break;
+    }
+}
+
+/**
+ * Toggle an LED.
+ *
+ * @note If id is a compile-time constant, consider using @ref LED_TOGGLE(id) instead.
+ *
+ * @param id    id of LED between 0 and 7
+ */
+static inline void led_toggle(unsigned id)
+{
+    switch (id) {
+        case 0: LED0_TOGGLE; break;
+        case 1: LED1_TOGGLE; break;
+        case 2: LED2_TOGGLE; break;
+        case 3: LED3_TOGGLE; break;
+        case 4: LED4_TOGGLE; break;
+        case 5: LED5_TOGGLE; break;
+        case 6: LED6_TOGGLE; break;
+        case 7: LED7_TOGGLE; break;
+    }
+}
+
 /** @} */
 
 #ifdef __cplusplus