output.hpp

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/**
 * @file output.hpp
 * @brief RGB LED output convenience functions
 * @ingroup hal
 *
 * Composes RgbLed state with a driver backend in a single call.
 * Two overloads:
 *   - GPIO backend: bang-bang write (on/off via GpioHandle)
 *   - SoftPwm backend: 8-bit duty cycle via channel indices
 *
 * Usage:
 *   // GPIO (bang-bang)
 *   sbl::led::write<sbl::driver::Gpio>(led, handle_r, handle_g, handle_b);
 *
 *   // SoftPwm (8-bit BCM)
 *   sbl::led::write<sbl::driver::SoftPwm>(led, ch_r, ch_g, ch_b);
 */
 
#ifndef SBL_HAL_LED_OUTPUT_HPP_
#define SBL_HAL_LED_OUTPUT_HPP_
 
#include <cstdint>
#include <sbl/types.hpp>
#include <sbl/components/display/rgb_led.hpp>
 
namespace sbl {
namespace led {
 
using RgbLed = sbl::components::display::RgbLed;
using RgbLedState = sbl::components::display::RgbLedState;
using Color = sbl::components::display::Color;
 
/**
 * @brief Write RgbLed state to GPIO pins (bang-bang)
 *
 * Reads the LED's current state and writes each channel to its GPIO pin.
 * Duty values > 0 are treated as ON. Gpio::write() handles active_low.
 *
 * @tparam Driver GPIO driver type (e.g., sbl::driver::Gpio)
 * @param led RGB LED instance to read state from
 * @param r   GPIO handle for red channel
 * @param g   GPIO handle for green channel
 * @param b   GPIO handle for blue channel
 *
 * @note ISR-safe — three GPIO register writes
 */
template<typename Driver>
inline void write(const RgbLed& led, const GpioHandle& r,
                  const GpioHandle& g, const GpioHandle& b) {
    auto s = led.state();
    Driver::write(r, s.r > 0);
    Driver::write(g, s.g > 0);
    Driver::write(b, s.b > 0);
}
 
/**
 * @brief Write RgbLed state via SoftPwm channels (8-bit BCM)
 *
 * Pushes per-channel duty cycles to the BCM engine.
 * The Driver must provide set_duty(uint8_t channel, uint8_t duty).
 *
 * @tparam Driver SoftPwm-compatible driver type (e.g., sbl::driver::SoftPwm)
 * @param led   RGB LED instance to read state from
 * @param r_ch  SoftPwm channel index for red
 * @param g_ch  SoftPwm channel index for green
 * @param b_ch  SoftPwm channel index for blue
 *
 * @note ISR-safe — three register writes to SoftPwm duty array
 */
template<typename Driver>
inline void write(const RgbLed& led, uint8_t r_ch, uint8_t g_ch, uint8_t b_ch) {
    auto s = led.state();
    Driver::set_duty(r_ch, s.r);
    Driver::set_duty(g_ch, s.g);
    Driver::set_duty(b_ch, s.b);
}
 
} // namespace led
} // namespace sbl
 
#endif // SBL_HAL_LED_OUTPUT_HPP_