diff options
Diffstat (limited to 'quantum/backlight/backlight_avr.c')
| -rw-r--r-- | quantum/backlight/backlight_avr.c | 50 |
1 files changed, 31 insertions, 19 deletions
diff --git a/quantum/backlight/backlight_avr.c b/quantum/backlight/backlight_avr.c index 9c972ae02e..f3a0252270 100644 --- a/quantum/backlight/backlight_avr.c +++ b/quantum/backlight/backlight_avr.c @@ -136,7 +136,7 @@ # define TCCRxB TCCR1B # define TIMERx_COMPA_vect TIMER1_COMPA_vect # define TIMERx_OVF_vect TIMER1_OVF_vect -# if defined(__AVR_ATmega32A__) // This MCU has only one TIMSK register +# if defined(__AVR_ATmega32A__) // This MCU has only one TIMSK register # define TIMSKx TIMSK # else # define TIMSKx TIMSK1 @@ -166,7 +166,7 @@ error("Please set 'BACKLIGHT_DRIVER = custom' within rules.mk") error("Please set 'BACKLIGHT_DRIVER = software' within rules.mk") #endif -#ifndef BACKLIGHT_PWM_TIMER // pwm through software +#ifndef BACKLIGHT_PWM_TIMER // pwm through software static inline void enable_pwm(void) { # if BACKLIGHT_ON_STATE == 1 @@ -203,7 +203,9 @@ static inline void disable_pwm(void) { // or F_CPU/BACKLIGHT_CUSTOM_RESOLUTION if used. // Triggered when the counter reaches the OCRx value -ISR(TIMERx_COMPA_vect) { backlight_pins_off(); } +ISR(TIMERx_COMPA_vect) { + backlight_pins_off(); +} // Triggered when the counter reaches the TOP value // this one triggers at F_CPU/ICRx = 16MHz/65536 =~ 244 Hz @@ -232,15 +234,15 @@ ISR(TIMERx_OVF_vect) { // See http://jared.geek.nz/2013/feb/linear-led-pwm static uint16_t cie_lightness(uint16_t v) { - if (v <= (uint32_t)ICRx / 12) // If the value is less than or equal to ~8% of max + if (v <= (uint32_t)ICRx / 12) // If the value is less than or equal to ~8% of max { - return v / 9; // Same as dividing by 900% + return v / 9; // Same as dividing by 900% } else { // In the next two lines values are bit-shifted. This is to avoid loosing decimals in integer math. - uint32_t y = (((uint32_t)v + (uint32_t)ICRx / 6) << 5) / ((uint32_t)ICRx / 6 + ICRx); // If above 8%, add ~16% of max, and normalize with (max + ~16% max) - uint32_t out = (y * y * y * ICRx) >> 15; // Cube it and undo the bit-shifting. (which is now three times as much due to the cubing) + uint32_t y = (((uint32_t)v + (uint32_t)ICRx / 6) << 5) / ((uint32_t)ICRx / 6 + ICRx); // If above 8%, add ~16% of max, and normalize with (max + ~16% max) + uint32_t out = (y * y * y * ICRx) >> 15; // Cube it and undo the bit-shifting. (which is now three times as much due to the cubing) - if (out > ICRx) // Avoid overflows + if (out > ICRx) // Avoid overflows { out = ICRx; } @@ -249,10 +251,14 @@ static uint16_t cie_lightness(uint16_t v) { } // rescale the supplied backlight value to be in terms of the value limit // range for val is [0..ICRx]. PWM pin is high while the timer count is below val. -static uint32_t rescale_limit_val(uint32_t val) { return (val * (BACKLIGHT_LIMIT_VAL + 1)) / 256; } +static uint32_t rescale_limit_val(uint32_t val) { + return (val * (BACKLIGHT_LIMIT_VAL + 1)) / 256; +} // range for val is [0..ICRx]. PWM pin is high while the timer count is below val. -static inline void set_pwm(uint16_t val) { OCRxx = val; } +static inline void set_pwm(uint16_t val) { + OCRxx = val; +} void backlight_set(uint8_t level) { if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS; @@ -303,7 +309,9 @@ static uint16_t breathing_freq_scale_factor = 2; # ifdef BACKLIGHT_PWM_TIMER static bool breathing = false; -bool is_breathing(void) { return breathing; } +bool is_breathing(void) { + return breathing; +} # define breathing_interrupt_enable() \ do { \ @@ -315,7 +323,9 @@ bool is_breathing(void) { return breathing; } } while (0) # else -bool is_breathing(void) { return !!(TIMSKx & _BV(TOIEx)); } +bool is_breathing(void) { + return !!(TIMSKx & _BV(TOIEx)); +} # define breathing_interrupt_enable() \ do { \ @@ -370,7 +380,9 @@ void breathing_self_disable(void) { static const uint8_t breathing_table[BREATHING_STEPS] PROGMEM = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 17, 20, 24, 28, 32, 36, 41, 46, 51, 57, 63, 70, 76, 83, 91, 98, 106, 113, 121, 129, 138, 146, 154, 162, 170, 178, 185, 193, 200, 207, 213, 220, 225, 231, 235, 240, 244, 247, 250, 252, 253, 254, 255, 254, 253, 252, 250, 247, 244, 240, 235, 231, 225, 220, 213, 207, 200, 193, 185, 178, 170, 162, 154, 146, 138, 129, 121, 113, 106, 98, 91, 83, 76, 70, 63, 57, 51, 46, 41, 36, 32, 28, 24, 20, 17, 15, 12, 10, 8, 6, 5, 4, 3, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; // Use this before the cie_lightness function. -static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); } +static inline uint16_t scale_backlight(uint16_t v) { + return v / BACKLIGHT_LEVELS * get_backlight_level(); +} # ifdef BACKLIGHT_PWM_TIMER void breathing_task(void) @@ -403,7 +415,7 @@ ISR(TIMERx_OVF_vect) set_pwm(cie_lightness(rescale_limit_val(scale_backlight((uint16_t)pgm_read_byte(&breathing_table[index]) * ICRx / 255)))); } -#endif // BACKLIGHT_BREATHING +#endif // BACKLIGHT_BREATHING void backlight_init_ports(void) { // Setup backlight pin as output and output to on state. @@ -415,10 +427,10 @@ void backlight_init_ports(void) { #ifdef BACKLIGHT_PWM_TIMER // TimerX setup, Fast PWM mode count to TOP set in ICRx - TCCRxA = _BV(WGM11); // = 0b00000010; + TCCRxA = _BV(WGM11); // = 0b00000010; // clock select clk/1 - TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; -#else // hardware PWM + TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; +#else // hardware PWM // Pin PB7 = OCR1C (Timer 1, Channel C) // Compare Output Mode = Clear on compare match, Channel C = COM1C1=1 COM1C0=0 // (i.e. start high, go low when counter matches.) @@ -430,8 +442,8 @@ void backlight_init_ports(void) { "In fast PWM mode, the compare units allow generation of PWM waveforms on the OCnx pins. Setting the COMnx1:0 bits to two will produce a non-inverted PWM [..]." "In fast PWM mode the counter is incremented until the counter value matches either one of the fixed values 0x00FF, 0x01FF, or 0x03FF (WGMn3:0 = 5, 6, or 7), the value in ICRn (WGMn3:0 = 14), or the value in OCRnA (WGMn3:0 = 15)." */ - TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010; - TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; + TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010; + TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; #endif #ifdef BACKLIGHT_CUSTOM_RESOLUTION |