55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
#include "backlight.h"
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#include "backlight_driver_common.h"
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#include "util.h"
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#ifdef BACKLIGHT_BREATHING
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# error "Backlight breathing is not available for software PWM. Please disable."
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#endif
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static uint16_t s_duty_pattern = 0;
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// clang-format off
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/** \brief PWM duty patterns
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*
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* We scale the current backlight level to an index within this array. This allows
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* backlight_task to focus on just switching LEDs on/off, and we can predict the duty pattern
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*/
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static const uint16_t backlight_duty_table[] = {
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0b0000000000000000,
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0b1000000000000000,
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0b1000000010000000,
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0b1000001000010000,
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0b1000100010001000,
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0b1001001001001000,
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0b1010101010101010,
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0b1110111011101110,
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0b1111111111111111,
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};
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#define backlight_duty_table_size ARRAY_SIZE(backlight_duty_table)
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// clang-format on
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static uint8_t scale_backlight(uint8_t v) {
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return v * (backlight_duty_table_size - 1) / BACKLIGHT_LEVELS;
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}
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void backlight_init_ports(void) {
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backlight_pins_init();
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}
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void backlight_set(uint8_t level) {
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s_duty_pattern = backlight_duty_table[scale_backlight(level)];
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}
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void backlight_task(void) {
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static uint8_t backlight_tick = 0;
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if (s_duty_pattern & ((uint16_t)1 << backlight_tick)) {
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backlight_pins_on();
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} else {
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backlight_pins_off();
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}
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backlight_tick = (backlight_tick + 1) % 16;
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}
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