led_control.c

/***************************************************************************//**
 * @file
 * @brief Led control for managing led hardware
 *******************************************************************************
 * # License
 * <b>Copyright 2018 Silicon Laboratories Inc. www.silabs.com</b>
 *******************************************************************************
 *
 * The licensor of this software is Silicon Laboratories Inc. Your use of this
 * software is governed by the terms of Silicon Labs Master Software License
 * Agreement (MSLA) available at
 * www.silabs.com/about-us/legal/master-software-license-agreement. This
 * software is distributed to you in Source Code format and is governed by the
 * sections of the MSLA applicable to Source Code.
 *
 ******************************************************************************/

#include "led_control.h"

#include "em_gpio.h"
#include "em_timer.h"
#include "em_cmu.h"

#include "hal-config-board.h"

/* board specific route locations to map timer PWM outputs to right pins */
#include "led_routeloc.h"

/***********************************************************************************************//**
 * @addtogroup LED
 * @{
 **************************************************************************************************/

/***********************************************************************************************//**
 * @addtogroup led_control
 * @{
 **************************************************************************************************/

/* LED polarity is active-low in those radio boards that share same pin for BUTTON/LED */
#ifdef FEATURE_LED_BUTTON_ON_SAME_PIN
#define LED_ACTIVE_LOW
#define LED_OFF_STATE 1
#define LED_ON_STATE  0
#else
#define LED_OFF_STATE 0
#define LED_ON_STATE  1
#endif

/***************************************************************************//**
 * Initialize TIMER0 as PWM source for LEDs.
 ******************************************************************************/
static void pwm_timer_init(void)
{
  TIMER_Init_TypeDef sTimerInit = TIMER_INIT_DEFAULT;
  TIMER_InitCC_TypeDef sInitCC = TIMER_INITCC_DEFAULT;
  CMU_ClockEnable(cmuClock_TIMER0, true);
  TIMER_Init(TIMER0, &sTimerInit);
  TIMER0->ROUTELOC0 = LED0_ROUTELOC | LED1_ROUTELOC;
  TIMER0->ROUTEPEN = TIMER_ROUTEPEN_CC0PEN | TIMER_ROUTEPEN_CC1PEN;

  sInitCC.mode = timerCCModePWM;
  TIMER_InitCC(TIMER0, 0, &sInitCC);
  TIMER_InitCC(TIMER0, 1, &sInitCC);

#ifdef LED_ACTIVE_LOW
  TIMER_CompareSet(TIMER0, 0, MAX_BRIGHTNESS);
  TIMER_CompareSet(TIMER0, 1, MAX_BRIGHTNESS);
#else
  TIMER_CompareSet(TIMER0, 0, MIN_BRIGHTNESS);
  TIMER_CompareSet(TIMER0, 1, MIN_BRIGHTNESS);
#endif

  TIMER_TopSet(TIMER0, 0xFFFF);

  TIMER_Enable(TIMER0, 1);
}

/*******************************************************************************
 * Initialize LEDs hardware.
 ******************************************************************************/
void LEDS_control_init(void)
{
  // configure LED pins
  GPIO_PinModeSet(BSP_LED0_PORT, BSP_LED0_PIN, gpioModePushPull, LED_OFF_STATE);
  GPIO_PinModeSet(BSP_LED1_PORT, BSP_LED1_PIN, gpioModePushPull, LED_OFF_STATE);
  pwm_timer_init();
}

/*******************************************************************************
 * Set LED color based on lightness and temperature.
 *
 * @param[in] level        Lightness level.
 * @param[in] temperature  Color temperature in Kelvins.
 *
 * @note On single color LEDs only lightness is changed.
 ******************************************************************************/
void LEDS_SetColor(uint16_t level, uint16_t temperature)
{
  /* all LED adjustments go trough this function. The polarity is taken into account by
   * flipping the level setting for boards with active-low LED control */
#ifdef LED_ACTIVE_LOW
  level = 0xFFFF - level;
#endif

  /* for simplicity, LEDs are driven with PWM in all states, even 0% and 100%.
   * Therefore need to limit the min/max value used for the timer CC register */
  if (level < MIN_BRIGHTNESS) {
    level = MIN_BRIGHTNESS;
  } else if (level > MAX_BRIGHTNESS) {
    level = MAX_BRIGHTNESS;
  }

  TIMER_CompareSet(TIMER0, 0, level);
  TIMER_CompareSet(TIMER0, 1, level);
}

/** @} (end addtogroup led_control) */
/** @} (end addtogroup LED) */