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Update software backlight to precalculated duty patterns

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This commit is contained in:
zvecr 2019-10-29 23:57:21 +00:00
parent 363cdb5fc0
commit 25d1901d7a
1 changed files with 30 additions and 7 deletions
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37
quantum/backlight/backlight_soft.c
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@ -20,6 +20,7 @@
{ BACKLIGHT_PIN }
#endif
static uint16_t s_duty_pattern = 0;
static const pin_t backlight_pins[] = BACKLIGHT_PIN_INIT;
#define BACKLIGHT_LED_COUNT (sizeof(backlight_pins) / sizeof(pin_t))
@ -46,21 +47,43 @@ void backlight_off(pin_t backlight_pin) {
}
void backlight_init_ports(void) {
// Setup backlight pin as output and output to on state.
FOR_EACH_LED(setPinOutput(backlight_pin); backlight_on(backlight_pin);)
// Setup backlight pin as output and output to off state.
FOR_EACH_LED(setPinOutput(backlight_pin); backlight_off(backlight_pin);)
}
// clang-format off
/** \brief PWM duty patterns
*
* We scale the current backlight level to an index within this array. This allows
* backlight_task to focus on just switching LEDs on/off, and we can predict the duty pattern
*/
static uint16_t backlight_duty_table[] = {
0b0000000000000000,
0b1000000000000000,
0b1000000010000000,
0b1000001000010000,
0b1000100010001000,
0b1001001001001000,
0b1010101010101010,
0b1110111011101110,
0b1111111111111111,
};
#define backlight_duty_table_size (sizeof(backlight_duty_table) / sizeof(backlight_duty_table[0]))
// clang-format on
static uint8_t scale_backlight(uint8_t v) { return v * (backlight_duty_table_size - 1) / BACKLIGHT_LEVELS; }
void backlight_set(uint8_t level) { s_duty_pattern = backlight_duty_table[scale_backlight(level)]; }
void backlight_task(void) {
static uint8_t backlight_tick = 0;
if ((0xFFFF >> (get_backlight_level() * ((BACKLIGHT_LEVELS + 1) / 2))) & (1 << backlight_tick)) {
if (s_duty_pattern & ((uint16_t)1 << backlight_tick)) {
FOR_EACH_LED(backlight_on(backlight_pin);)
} else {
FOR_EACH_LED(backlight_off(backlight_pin);)
}
backlight_tick = (backlight_tick + 1) % 16;
}
void backlight_set(uint8_t level) {
// noop as backlight_task uses get_backlight_level()
}