From cb2331713c84bb2b7f140f67b41037721f4958a1 Mon Sep 17 00:00:00 2001 From: Ryan Date: Sat, 8 Jul 2023 23:13:10 +1000 Subject: Relocate backlight drivers (#21444) --- drivers/backlight/backlight_software.c | 54 ++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 drivers/backlight/backlight_software.c (limited to 'drivers/backlight/backlight_software.c') diff --git a/drivers/backlight/backlight_software.c b/drivers/backlight/backlight_software.c new file mode 100644 index 0000000000..f2af3e918e --- /dev/null +++ b/drivers/backlight/backlight_software.c @@ -0,0 +1,54 @@ +#include "backlight.h" +#include "backlight_driver_common.h" +#include "util.h" + +#ifdef BACKLIGHT_BREATHING +# error "Backlight breathing is not available for software PWM. Please disable." +#endif + +static uint16_t s_duty_pattern = 0; + +// 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 const uint16_t backlight_duty_table[] = { + 0b0000000000000000, + 0b1000000000000000, + 0b1000000010000000, + 0b1000001000010000, + 0b1000100010001000, + 0b1001001001001000, + 0b1010101010101010, + 0b1110111011101110, + 0b1111111111111111, +}; +#define backlight_duty_table_size ARRAY_SIZE(backlight_duty_table) + +// clang-format on + +static uint8_t scale_backlight(uint8_t v) { + return v * (backlight_duty_table_size - 1) / BACKLIGHT_LEVELS; +} + +void backlight_init_ports(void) { + backlight_pins_init(); +} + +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 (s_duty_pattern & ((uint16_t)1 << backlight_tick)) { + backlight_pins_on(); + } else { + backlight_pins_off(); + } + backlight_tick = (backlight_tick + 1) % 16; +} -- cgit v1.2.3