diff options
Diffstat (limited to 'platforms/avr/drivers/backlight_pwm.c')
| -rw-r--r-- | platforms/avr/drivers/backlight_pwm.c | 200 |
1 files changed, 32 insertions, 168 deletions
diff --git a/platforms/avr/drivers/backlight_pwm.c b/platforms/avr/drivers/backlight_pwm.c index d234115641..74d25753a4 100644 --- a/platforms/avr/drivers/backlight_pwm.c +++ b/platforms/avr/drivers/backlight_pwm.c @@ -1,5 +1,5 @@ #include "backlight.h" -#include "backlight_driver_common.h" +#include "gpio.h" #include "progmem.h" #include <avr/io.h> #include <avr/interrupt.h> @@ -9,14 +9,6 @@ # define BACKLIGHT_LIMIT_VAL 255 #endif -// This logic is a bit complex, we support 3 setups: -// -// 1. Hardware PWM when backlight is wired to a PWM pin. -// Depending on this pin, we use a different output compare unit. -// 2. Software PWM with hardware timers, but the used timer -// depends on the Audio setup (Audio wins over Backlight). -// 3. Full software PWM, driven by the matrix scan, if both timers are used by Audio. - #if (defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) && (BACKLIGHT_PIN == B5 || BACKLIGHT_PIN == B6 || BACKLIGHT_PIN == B7) # define ICRx ICR1 # define TCCRxA TCCR1A @@ -122,106 +114,34 @@ # define COMxx1 COM1B1 # define OCRxx OCR1B # endif -#elif (AUDIO_PIN != B5) && (AUDIO_PIN != B6) && (AUDIO_PIN != B7) && (AUDIO_PIN_ALT != B5) && (AUDIO_PIN_ALT != B6) && (AUDIO_PIN_ALT != B7) -// Timer 1 is not in use by Audio feature, Backlight can use it -# pragma message "Using hardware timer 1 with software PWM" -# define BACKLIGHT_PWM_TIMER -# define ICRx ICR1 -# define TCCRxA TCCR1A -# 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 -# define TIMSKx TIMSK -# else -# define TIMSKx TIMSK1 -# endif -# define TOIEx TOIE1 +#endif -# define OCIExA OCIE1A -# define OCRxx OCR1A -#elif (AUDIO_PIN != C4) && (AUDIO_PIN != C5) && (AUDIO_PIN != C6) -# pragma message "Using hardware timer 3 with software PWM" -// Timer 3 is not in use by Audio feature, Backlight can use it -# define BACKLIGHT_PWM_TIMER -# define ICRx ICR1 -# define TCCRxA TCCR3A -# define TCCRxB TCCR3B -# define TIMERx_COMPA_vect TIMER3_COMPA_vect -# define TIMERx_OVF_vect TIMER3_OVF_vect -# define TIMSKx TIMSK3 -# define TOIEx TOIE3 +#ifndef BACKLIGHT_RESOLUTION +# define BACKLIGHT_RESOLUTION 0xFFFFU +#endif -# define OCIExA OCIE3A -# define OCRxx OCR3A +#if (BACKLIGHT_RESOLUTION > 0xFFFF || BACKLIGHT_RESOLUTION < 0x00FF) +# error "Backlight resolution must be between 0x00FF and 0xFFFF" #endif -#ifndef BACKLIGHT_PWM_TIMER // pwm through software +#define BREATHING_SCALE_FACTOR F_CPU / BACKLIGHT_RESOLUTION / 120 static inline void enable_pwm(void) { -# if BACKLIGHT_ON_STATE == 1 +#if BACKLIGHT_ON_STATE == 1 TCCRxA |= _BV(COMxx1); -# else +#else TCCRxA |= _BV(COMxx1) | _BV(COMxx0); -# endif +#endif } static inline void disable_pwm(void) { -# if BACKLIGHT_ON_STATE == 1 +#if BACKLIGHT_ON_STATE == 1 TCCRxA &= ~(_BV(COMxx1)); -# else +#else TCCRxA &= ~(_BV(COMxx1) | _BV(COMxx0)); -# endif -} - #endif - -#ifdef BACKLIGHT_PWM_TIMER - -// The idea of software PWM assisted by hardware timers is the following -// we use the hardware timer in fast PWM mode like for hardware PWM, but -// instead of letting the Output Match Comparator control the led pin -// (which is not possible since the backlight is not wired to PWM pins on the -// CPU), we do the LED on/off by oursleves. -// The timer is setup to count up to 0xFFFF, and we set the Output Compare -// register to the current 16bits backlight level (after CIE correction). -// This means the CPU will trigger a compare match interrupt when the counter -// reaches the backlight level, where we turn off the LEDs, -// but also an overflow interrupt when the counter rolls back to 0, -// in which we're going to turn on the LEDs. -// The LED will then be on for OCRxx/0xFFFF time, adjusted every 244Hz, -// or F_CPU/BACKLIGHT_CUSTOM_RESOLUTION if used. - -// Triggered when the counter reaches the OCRx value -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 -ISR(TIMERx_OVF_vect) { -# ifdef BACKLIGHT_BREATHING - if (is_breathing()) { - breathing_task(); - } -# endif - // for very small values of OCRxx (or backlight level) - // we can't guarantee this whole code won't execute - // at the same time as the compare match interrupt - // which means that we might turn on the leds while - // trying to turn them off, leading to flickering - // artifacts (especially while breathing, because breathing_task - // takes many computation cycles). - // so better not turn them on while the counter TOP is very low. - if (OCRxx > ICRx / 250 + 5) { - backlight_pins_on(); - } -} - -#endif - -#define TIMER_TOP 0xFFFFU - // 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 @@ -254,26 +174,11 @@ void backlight_set(uint8_t level) { if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS; if (level == 0) { -#ifdef BACKLIGHT_PWM_TIMER - if (OCRxx) { - TIMSKx &= ~(_BV(OCIExA)); - TIMSKx &= ~(_BV(TOIEx)); - } -#else // Turn off PWM control on backlight pin disable_pwm(); -#endif - backlight_pins_off(); } else { -#ifdef BACKLIGHT_PWM_TIMER - if (!OCRxx) { - TIMSKx |= _BV(OCIExA); - TIMSKx |= _BV(TOIEx); - } -#else // Turn on PWM control of backlight pin enable_pwm(); -#endif } // Set the brightness set_pwm(cie_lightness(rescale_limit_val(ICRx * (uint32_t)level / BACKLIGHT_LEVELS))); @@ -282,7 +187,6 @@ void backlight_set(uint8_t level) { void backlight_task(void) {} #ifdef BACKLIGHT_BREATHING - # define BREATHING_NO_HALT 0 # define BREATHING_HALT_OFF 1 # define BREATHING_HALT_ON 2 @@ -293,39 +197,20 @@ static uint16_t breathing_counter = 0; static uint8_t breath_scale_counter = 1; /* Run the breathing loop at ~120Hz*/ -const uint8_t breathing_ISR_frequency = 120; -static uint16_t breathing_freq_scale_factor = 2; - -# ifdef BACKLIGHT_PWM_TIMER -static bool breathing = false; - -bool is_breathing(void) { - return breathing; -} - -# define breathing_interrupt_enable() \ - do { \ - breathing = true; \ - } while (0) -# define breathing_interrupt_disable() \ - do { \ - breathing = false; \ - } while (0) -# else +const uint8_t breathing_ISR_frequency = 120; bool is_breathing(void) { return !!(TIMSKx & _BV(TOIEx)); } -# define breathing_interrupt_enable() \ - do { \ - TIMSKx |= _BV(TOIEx); \ - } while (0) -# define breathing_interrupt_disable() \ - do { \ - TIMSKx &= ~_BV(TOIEx); \ - } while (0) -# endif +# define breathing_interrupt_enable() \ + do { \ + TIMSKx |= _BV(TOIEx); \ + } while (0) +# define breathing_interrupt_disable() \ + do { \ + TIMSKx &= ~_BV(TOIEx); \ + } while (0) # define breathing_min() \ do { \ @@ -374,20 +259,14 @@ static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); } -# ifdef BACKLIGHT_PWM_TIMER -void breathing_task(void) -# else /* Assuming a 16MHz CPU clock and a timer that resets at 64k (ICR1), the following interrupt handler will run * about 244 times per second. * * The following ISR runs at F_CPU/ISRx. With a 16MHz clock and default pwm resolution, that means 244Hz */ -ISR(TIMERx_OVF_vect) -# endif -{ - +ISR(TIMERx_OVF_vect) { // Only run this ISR at ~120 Hz - if (breath_scale_counter++ == breathing_freq_scale_factor) { + if (breath_scale_counter++ == BREATHING_SCALE_FACTOR) { breath_scale_counter = 1; } else { return; @@ -412,19 +291,17 @@ ISR(TIMERx_OVF_vect) #endif // BACKLIGHT_BREATHING void backlight_init_ports(void) { - // Setup backlight pin as output and output to on state. - backlight_pins_init(); + setPinOutput(BACKLIGHT_PIN); +#if BACKLIGHT_ON_STATE == 1 + writePinLow(BACKLIGHT_PIN); +#else + writePinHigh(BACKLIGHT_PIN); +#endif // I could write a wall of text here to explain... but TL;DW // Go read the ATmega32u4 datasheet. // And this: http://blog.saikoled.com/post/43165849837/secret-konami-cheat-code-to-high-resolution-pwm-on -#ifdef BACKLIGHT_PWM_TIMER - // TimerX setup, Fast PWM mode count to TOP set in ICRx - TCCRxA = _BV(WGM11); // = 0b00000010; - // clock select clk/1 - 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.) @@ -438,23 +315,10 @@ void backlight_init_ports(void) { */ TCCRxA = _BV(COMxx1) | _BV(WGM11); // = 0b00001010; TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10); // = 0b00011001; -#endif - -#ifdef BACKLIGHT_CUSTOM_RESOLUTION -# if (BACKLIGHT_CUSTOM_RESOLUTION > 0xFFFF || BACKLIGHT_CUSTOM_RESOLUTION < 1) -# error "This out of range of the timer capabilities" -# elif (BACKLIGHT_CUSTOM_RESOLUTION < 0xFF) -# warning "Resolution lower than 0xFF isn't recommended" -# endif -# ifdef BACKLIGHT_BREATHING - breathing_freq_scale_factor = F_CPU / BACKLIGHT_CUSTOM_RESOLUTION / 120; -# endif - ICRx = BACKLIGHT_CUSTOM_RESOLUTION; -#else - ICRx = TIMER_TOP; -#endif + ICRx = BACKLIGHT_RESOLUTION; backlight_init(); + #ifdef BACKLIGHT_BREATHING if (is_backlight_breathing()) { breathing_enable(); |