keyboards/jj40/backlight.c

   1 /**
   2  * Backlighting code for PS2AVRGB boards (ATMEGA32A)
   3  * Kenneth A. (github.com/krusli | krusli.me)
   4  */
   5
   6 #include "backlight.h"
   7 #include "quantum.h"
   8
   9 #include <avr/pgmspace.h>
  10 #include <avr/interrupt.h>
  11
  12 #include "backlight_custom.h"
  13 #include "breathing_custom.h"
  14
  15 // DEBUG
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18
  19 // Port D: digital pins of the AVR chipset
  20 #define NUMLOCK_PORT    (1 << 1)  // 1st pin of Port D (digital)
  21 #define CAPSLOCK_PORT   (1 << 2)  // 2nd pin
  22 #define BACKLIGHT_PORT  (1 << 4)  // 4th pin
  23 #define SCROLLLOCK_PORT (1 << 6)  // 6th pin
  24
  25 #define TIMER_CLK_DIV64                   0x03  ///< Timer clocked at F_CPU/64
  26 #define TIMER1PRESCALE  TIMER_CLK_DIV64 ///< timer 1 prescaler default
  27
  28 #define TIMER_PRESCALE_MASK             0x07    ///< Timer Prescaler Bit-Mask
  29
  30 #define PWM_MAX 0xFF
  31 #define TIMER_TOP 255 // 8 bit PWM
  32
  33 extern backlight_config_t backlight_config;
  34
  35 /**
  36  * References
  37  * Port Registers: https://www.arduino.cc/en/Reference/PortManipulation
  38  * TCCR1A: https://electronics.stackexchange.com/questions/92350/what-is-the-difference-between-tccr1a-and-tccr1b
  39  * Timers: http://www.avrbeginners.net/architecture/timers/timers.html
  40  * 16-bit timer setup: http://sculland.com/ATmega168/Interrupts-And-Timers/16-Bit-Timer-Setup/
  41  * PS2AVRGB firmware: https://github.com/showjean/ps2avrU/tree/master/firmware
  42  */
  43
  44 // @Override
  45 // turn LEDs on and off depending on USB caps/num/scroll lock states.
  46 void led_set_user(uint8_t usb_led) {
  47     if (usb_led & (1 << USB_LED_NUM_LOCK)) {
  48       // turn on
  49       DDRD  |= NUMLOCK_PORT;
  50       PORTD |= NUMLOCK_PORT;
  51     } else {
  52       // turn off
  53       DDRD  &= ~NUMLOCK_PORT;
  54       PORTD &= ~NUMLOCK_PORT;
  55     }
  56
  57     if (usb_led & (1 << USB_LED_CAPS_LOCK)) {
  58       DDRD  |= CAPSLOCK_PORT;
  59       PORTD |= CAPSLOCK_PORT;
  60     } else {
  61       DDRD  &= ~CAPSLOCK_PORT;
  62       PORTD &= ~CAPSLOCK_PORT;
  63     }
  64
  65     if (usb_led & (1 << USB_LED_SCROLL_LOCK)) {
  66       DDRD  |= SCROLLLOCK_PORT;
  67       PORTD |= SCROLLLOCK_PORT;
  68     } else {
  69       DDRD  &= ~SCROLLLOCK_PORT;
  70       PORTD &= ~SCROLLLOCK_PORT;
  71     }
  72 }
  73
  74 #ifdef BACKLIGHT_ENABLE
  75
  76 // sets up Timer 1 for 8-bit PWM
  77 void timer1PWMSetup(void) { // NOTE ONLY CALL THIS ONCE
  78   // default 8 bit mode
  79   TCCR1A &= ~(1 << 1); // cbi(TCCR1A,PWM11); <- set PWM11 bit to HIGH
  80   TCCR1A |= (1 << 0);  // sbi(TCCR1A,PWM10); <- set PWM10 bit to LOW
  81
  82   // clear output compare value A
  83   // outb(OCR1AH, 0);
  84   // outb(OCR1AL, 0);
  85
  86   // clear output comparator registers for B
  87         OCR1BH = 0; // outb(OCR1BH, 0);
  88         OCR1BL = 0; // outb(OCR1BL, 0);
  89 }
  90
  91 bool is_init = false;
  92 void timer1Init(void) {
  93   // timer1SetPrescaler(TIMER1PRESCALE)
  94   // set to DIV/64
  95   (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | TIMER1PRESCALE;
  96
  97   // reset TCNT1
  98   TCNT1H = 0;  // outb(TCNT1H, 0);
  99         TCNT1L = 0;  // outb(TCNT1L, 0);
 100
 101   // TOIE1: Timer Overflow Interrupt Enable (Timer 1);
 102         TIMSK |= _BV(TOIE1); // sbi(TIMSK, TOIE1);
 103
 104   is_init = true;
 105 }
 106
 107 void timer1UnInit(void) {
 108   // set prescaler back to NONE
 109   (TCCR1B) = ((TCCR1B) & ~TIMER_PRESCALE_MASK) | 0x00;  // TIMERRTC_CLK_STOP
 110
 111   // disable timer overflow interrupt
 112   TIMSK &= ~_BV(TOIE1); // overflow bit?
 113
 114   setPWM(0);
 115
 116   is_init = false;
 117 }
 118
 119
 120 // handle TCNT1 overflow
 121 //! Interrupt handler for tcnt1 overflow interrupt
 122 ISR(TIMER1_OVF_vect, ISR_NOBLOCK)
 123 {
 124         // sei();
 125   // handle breathing here
 126   #ifdef BACKLIGHT_BREATHING
 127   if (is_breathing()) {
 128     custom_breathing_handler();
 129   }
 130   #endif
 131
 132   // TODO call user defined function
 133 }
 134
 135 // enable timer 1 PWM
 136 // timer1PWMBOn()
 137 void timer1PWMBEnable(void) {
 138   // turn on channel B (OC1B) PWM output
 139   // set OC1B as non-inverted PWM
 140   TCCR1A |= _BV(COM1B1);
 141   TCCR1A &= ~_BV(COM1B0);
 142 }
 143
 144 // disable timer 1 PWM
 145 // timer1PWMBOff()
 146 void timer1PWMBDisable(void) {
 147   TCCR1A &= ~_BV(COM1B1);
 148   TCCR1A &= ~_BV(COM1B0);
 149 }
 150
 151 void enableBacklight(void) {
 152   DDRD  |= BACKLIGHT_PORT;  // set digital pin 4 as output
 153   PORTD |= BACKLIGHT_PORT;  // set digital pin 4 to high
 154 }
 155
 156 void disableBacklight(void) {
 157   // DDRD  &= ~BACKLIGHT_PORT;  // set digital pin 4 as input
 158   PORTD &= ~BACKLIGHT_PORT;  // set digital pin 4 to low
 159 }
 160
 161 void startPWM(void) {
 162   timer1Init();
 163   timer1PWMBEnable();
 164   enableBacklight();
 165 }
 166
 167 void stopPWM(void) {
 168   timer1UnInit();
 169   disableBacklight();
 170   timer1PWMBDisable();
 171 }
 172
 173 void b_led_init_ports(void) {
 174   /* turn backlight on/off depending on user preference */
 175   #if BACKLIGHT_ON_STATE == 0
 176     // DDRx register: sets the direction of Port D
 177     // DDRD  &= ~BACKLIGHT_PORT;  // set digital pin 4 as input
 178     PORTD &= ~BACKLIGHT_PORT;  // set digital pin 4 to low
 179   #else
 180     DDRD  |= BACKLIGHT_PORT;  // set digital pin 4 as output
 181     PORTD |= BACKLIGHT_PORT;  // set digital pin 4 to high
 182   #endif
 183
 184   timer1PWMSetup();
 185   startPWM();
 186
 187   #ifdef BACKLIGHT_BREATHING
 188   breathing_enable();
 189   #endif
 190 }
 191
 192 void b_led_set(uint8_t level) {
 193   if (level > BACKLIGHT_LEVELS) {
 194     level = BACKLIGHT_LEVELS;
 195   }
 196
 197   setPWM((int)(TIMER_TOP * (float) level / BACKLIGHT_LEVELS));
 198 }
 199
 200 // called every matrix scan
 201 void b_led_task(void) {
 202   // do nothing for now
 203 }
 204
 205 void setPWM(uint16_t xValue) {
 206   if (xValue > TIMER_TOP) {
 207     xValue = TIMER_TOP;
 208   }
 209   OCR1B = xValue; // timer1PWMBSet(xValue);
 210 }
 211
 212 #endif  // BACKLIGHT_ENABLE