qmk_firmware

QMK firmware for my keyboards (Corne, Sweep Ferris) and trackball (Ploopy Adept)
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backlight_software.c (1365B)

      1 #include "backlight.h"
      2 #include "backlight_driver_common.h"
      3 #include "util.h"
      4 
      5 #ifdef BACKLIGHT_BREATHING
      6 #    error "Backlight breathing is not available for software PWM. Please disable."
      7 #endif
      8 
      9 static uint16_t s_duty_pattern = 0;
     10 
     11 // clang-format off
     12 
     13 /** \brief PWM duty patterns
     14  *
     15  * We scale the current backlight level to an index within this array. This allows
     16  * backlight_task to focus on just switching LEDs on/off, and we can predict the duty pattern
     17  */
     18 static const uint16_t backlight_duty_table[] = {
     19     0b0000000000000000,
     20     0b1000000000000000,
     21     0b1000000010000000,
     22     0b1000001000010000,
     23     0b1000100010001000,
     24     0b1001001001001000,
     25     0b1010101010101010,
     26     0b1110111011101110,
     27     0b1111111111111111,
     28 };
     29 #define backlight_duty_table_size ARRAY_SIZE(backlight_duty_table)
     30 
     31 // clang-format on
     32 
     33 static uint8_t scale_backlight(uint8_t v) {
     34     return v * (backlight_duty_table_size - 1) / BACKLIGHT_LEVELS;
     35 }
     36 
     37 void backlight_init_ports(void) {
     38     backlight_pins_init();
     39 }
     40 
     41 void backlight_set(uint8_t level) {
     42     s_duty_pattern = backlight_duty_table[scale_backlight(level)];
     43 }
     44 
     45 void backlight_task(void) {
     46     static uint8_t backlight_tick = 0;
     47 
     48     if (s_duty_pattern & ((uint16_t)1 << backlight_tick)) {
     49         backlight_pins_on();
     50     } else {
     51         backlight_pins_off();
     52     }
     53     backlight_tick = (backlight_tick + 1) % 16;
     54 }