/*
 * rgbled.c
 *
 * using TIM2 CH1-CH3
 *
 * * errata:
 * - board design makes overcurrent on GAT port practically impossible.
 *   overcurrent condition may either trip low voltage condition due to
 *   decoupling or voltage output limit on LDO. as such, displaying
 *   any overcurrent state is meaningless.
 */

#include <ch32v20x.h>
#include <stdint.h>

#include "periph/btn.h"
#include "periph/port_pwr.h"
#include "periph/rtc.h"



#define RED         0
#define GRN         1
#define BLU         2

#define BRT_RED     40
#define BRT_GRN     32
#define BRT_BLU     36
#define BRT_OFF     0

#define RGBLED_TIM  TIM2



static uint8_t flash_timeout[3];
static uint8_t flash[3] = {0};
static uint8_t state[3] = {0};



void rgbled_set()
{
    int8_t i;
    uint16_t out[3];

    // flash counters
    for (i = 0; i < 3; i++) {
        if (!flash[i]) {
            flash[i] = flash_timeout[i];
        } else flash[i]--;

        switch (flash_timeout[i]) {
            // always on
            case 0x00: {
                state[i] = 1;
                break;
            }

            // always off
            case 0xff: {
                state[i] = 0;
                break;
            }

            // standard
            default: {
                if (flash[i] == flash_timeout[i]) {
                    state[i] ^= 1;
                }
            }
        }
    }

    out[BLU] = BRT_BLU;
    out[GRN] = BRT_GRN;
    out[RED] = BRT_RED;

    for (i = 0; i < 3; i++) {
        // jumper 1 will reduce brightness
        if (btn[DIP1]._mask & BTN_PUSH) {
            out[i] >>= 2;
        }

        // jumper 2 will turn off LEDs entirely
        if (btn[DIP2]._mask & BTN_PUSH) {
            out[i] = BRT_OFF;
        }
    }

    RGBLED_TIM->CH1CVR = state[BLU] ? out[BLU] : BRT_OFF;
    RGBLED_TIM->CH2CVR = state[GRN] ? out[GRN] : BRT_OFF;
    RGBLED_TIM->CH3CVR = state[RED] ? out[RED] : BRT_OFF;
}

void rgbled_update()
{
    // VCR flash if clock isn't set
    /*
    switch (rtc_state) {
        case RTC_STATE_CLOCK_NOT_SET: {
            flash_timeout[BLU] = 48;
            break;
        }
        default: {
            flash_timeout[BLU] = 0;
            break;
        }
    }
    */

    // see errata on why we aren't showing overcurrent status anymore
    // flash_timeout[RED] = gat_oc_state()  ? 16 : 0xff;

    // power output state
    flash_timeout[GRN] = gat_pwr_state()  ? 0 : 0xff;
    flash_timeout[RED] = usb2_pwr_state() ? 0 : 0xff;

    rgbled_set();
}

void rgbled_init()
{
    TIM_TimeBaseInitTypeDef timer = {0};
    TIM_OCInitTypeDef pwm = {0};

    timer.TIM_Period = (1 << 10) - 1;       // 10-bit
    timer.TIM_Prescaler = 0;
    timer.TIM_ClockDivision = TIM_CKD_DIV1;
    timer.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(RGBLED_TIM, &timer);

    pwm.TIM_OCMode = TIM_OCMode_PWM1;
    pwm.TIM_OutputState = TIM_OutputState_Enable;
    pwm.TIM_Pulse = BRT_OFF;
    pwm.TIM_OCPolarity = TIM_OCPolarity_Low;

    TIM_OC1PreloadConfig(RGBLED_TIM, TIM_OCPreload_Disable);
    TIM_OC2PreloadConfig(RGBLED_TIM, TIM_OCPreload_Disable);
    TIM_OC3PreloadConfig(RGBLED_TIM, TIM_OCPreload_Disable);
    TIM_ARRPreloadConfig(RGBLED_TIM, ENABLE);

    TIM_OC1Init(RGBLED_TIM, &pwm);
    TIM_OC2Init(RGBLED_TIM, &pwm);
    TIM_OC3Init(RGBLED_TIM, &pwm);
    TIM_CtrlPWMOutputs(RGBLED_TIM, ENABLE);

    RGBLED_TIM->CNT = 0;
    TIM_Cmd(RGBLED_TIM, ENABLE);

    flash_timeout[BLU] = flash_timeout[GRN] = flash_timeout[RED] = 0xff;
}