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Prune out pure software pwm && custom driver && remove wrapping BACKLIGHT_PIN (#8041)

This commit is contained in:
Joel Challis 2020-03-01 20:22:13 +00:00 committed by GitHub
parent 3dc061ac78
commit 88356c85c4
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@ -2,7 +2,9 @@
#include "backlight.h"
#include "debug.h"
#if defined(BACKLIGHT_ENABLE) && (defined(BACKLIGHT_PIN) || defined(BACKLIGHT_PINS))
#if !defined(BACKLIGHT_PIN) && !defined(BACKLIGHT_PINS)
# error "Backlight pin/pins not defined. Please configure."
#endif
// This logic is a bit complex, we support 3 setups:
//
@ -12,262 +14,223 @@
// 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 HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
#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 HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
# if BACKLIGHT_PIN == B5
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# elif BACKLIGHT_PIN == B6
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == B7
# define COMxx0 COM1C0
# define COMxx1 COM1C1
# define OCRxx OCR1C
# endif
# elif (defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) && (BACKLIGHT_PIN == C4 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6)
# define HARDWARE_PWM
# define ICRx ICR3
# define TCCRxA TCCR3A
# define TCCRxB TCCR3B
# define TIMERx_OVF_vect TIMER3_OVF_vect
# define TIMSKx TIMSK3
# define TOIEx TOIE3
# if BACKLIGHT_PIN == B5
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# elif BACKLIGHT_PIN == B6
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == B7
# define COMxx0 COM1C0
# define COMxx1 COM1C1
# define OCRxx OCR1C
# endif
#elif (defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB1287__) || defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__)) && (BACKLIGHT_PIN == C4 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6)
# define HARDWARE_PWM
# define ICRx ICR3
# define TCCRxA TCCR3A
# define TCCRxB TCCR3B
# define TIMERx_OVF_vect TIMER3_OVF_vect
# define TIMSKx TIMSK3
# define TOIEx TOIE3
# if BACKLIGHT_PIN == C4
# if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
# error This MCU has no C4 pin!
# else
# define COMxx0 COM3C0
# define COMxx1 COM3C1
# define OCRxx OCR3C
# endif
# elif BACKLIGHT_PIN == C5
# if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
# error This MCU has no C5 pin!
# else
# define COMxx0 COM3B0
# define COMxx1 COM3B1
# define OCRxx OCR3B
# endif
# elif BACKLIGHT_PIN == C6
# define COMxx0 COM3A0
# define COMxx1 COM3A1
# define OCRxx OCR3A
# endif
# elif (defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__)) && (BACKLIGHT_PIN == B7 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
# if BACKLIGHT_PIN == B7
# define COMxx0 COM1C0
# define COMxx1 COM1C1
# define OCRxx OCR1C
# elif BACKLIGHT_PIN == C5
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == C6
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# endif
# elif defined(__AVR_ATmega32A__) && (BACKLIGHT_PIN == D4 || BACKLIGHT_PIN == D5)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK
# define TOIEx TOIE1
# if BACKLIGHT_PIN == D4
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == D5
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# endif
# elif defined(__AVR_ATmega328P__) && (BACKLIGHT_PIN == B1 || BACKLIGHT_PIN == B2)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
# if BACKLIGHT_PIN == B1
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# elif BACKLIGHT_PIN == B2
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# endif
# else
# if !defined(BACKLIGHT_CUSTOM_DRIVER)
# if !defined(B5_AUDIO) && !defined(B6_AUDIO) && !defined(B7_AUDIO)
// Timer 1 is not in use by Audio feature, Backlight can use it
# pragma message "Using hardware timer 1 with software PWM"
# define HARDWARE_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
# define OCIExA OCIE1A
# define OCRxx OCR1A
# elif !defined(C6_AUDIO) && !defined(C5_AUDIO) && !defined(C4_AUDIO)
# pragma message "Using hardware timer 3 with software PWM"
// Timer 3 is not in use by Audio feature, Backlight can use it
# define HARDWARE_PWM
# 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
# define OCIExA OCIE3A
# define OCRxx OCR3A
# else
# pragma message "Audio in use - using pure software PWM"
# define NO_HARDWARE_PWM
# endif
# if BACKLIGHT_PIN == C4
# if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
# error This MCU has no C4 pin!
# else
# pragma message "Custom driver defined - using pure software PWM"
# define NO_HARDWARE_PWM
# define COMxx0 COM3C0
# define COMxx1 COM3C1
# define OCRxx OCR3C
# endif
# elif BACKLIGHT_PIN == C5
# if (defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__))
# error This MCU has no C5 pin!
# else
# define COMxx0 COM3B0
# define COMxx1 COM3B1
# define OCRxx OCR3B
# endif
# elif BACKLIGHT_PIN == C6
# define COMxx0 COM3A0
# define COMxx1 COM3A1
# define OCRxx OCR3A
# endif
#elif (defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__)) && (BACKLIGHT_PIN == B7 || BACKLIGHT_PIN == C5 || BACKLIGHT_PIN == C6)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
# ifndef BACKLIGHT_ON_STATE
# define BACKLIGHT_ON_STATE 1
# if BACKLIGHT_PIN == B7
# define COMxx0 COM1C0
# define COMxx1 COM1C1
# define OCRxx OCR1C
# elif BACKLIGHT_PIN == C5
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == C6
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# endif
#elif defined(__AVR_ATmega32A__) && (BACKLIGHT_PIN == D4 || BACKLIGHT_PIN == D5)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK
# define TOIEx TOIE1
# if BACKLIGHT_PIN == D4
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# elif BACKLIGHT_PIN == D5
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# endif
#elif defined(__AVR_ATmega328P__) && (BACKLIGHT_PIN == B1 || BACKLIGHT_PIN == B2)
# define HARDWARE_PWM
# define ICRx ICR1
# define TCCRxA TCCR1A
# define TCCRxB TCCR1B
# define TIMERx_OVF_vect TIMER1_OVF_vect
# define TIMSKx TIMSK1
# define TOIEx TOIE1
# if BACKLIGHT_PIN == B1
# define COMxx0 COM1A0
# define COMxx1 COM1A1
# define OCRxx OCR1A
# elif BACKLIGHT_PIN == B2
# define COMxx0 COM1B0
# define COMxx1 COM1B1
# define OCRxx OCR1B
# endif
#elif !defined(B5_AUDIO) && !defined(B6_AUDIO) && !defined(B7_AUDIO)
// Timer 1 is not in use by Audio feature, Backlight can use it
# pragma message "Using hardware timer 1 with software PWM"
# define HARDWARE_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
# define OCIExA OCIE1A
# define OCRxx OCR1A
#elif !defined(C6_AUDIO) && !defined(C5_AUDIO) && !defined(C4_AUDIO)
# pragma message "Using hardware timer 3 with software PWM"
// Timer 3 is not in use by Audio feature, Backlight can use it
# define HARDWARE_PWM
# 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
# define OCIExA OCIE3A
# define OCRxx OCR3A
#elif defined(BACKLIGHT_CUSTOM_DRIVER)
error("Please set 'BACKLIGHT_DRIVER = custom' within rules.mk")
#else
error("Please set 'BACKLIGHT_DRIVER = software' within rules.mk")
#endif
#ifndef BACKLIGHT_ON_STATE
# define BACKLIGHT_ON_STATE 1
#endif
void backlight_on(pin_t backlight_pin) {
# if BACKLIGHT_ON_STATE == 1
#if BACKLIGHT_ON_STATE == 1
writePinHigh(backlight_pin);
# else
#else
writePinLow(backlight_pin);
# endif
#endif
}
void backlight_off(pin_t backlight_pin) {
# if BACKLIGHT_ON_STATE == 1
#if BACKLIGHT_ON_STATE == 1
writePinLow(backlight_pin);
# else
#else
writePinHigh(backlight_pin);
# endif
#endif
}
# if defined(NO_HARDWARE_PWM) || defined(BACKLIGHT_PWM_TIMER) // pwm through software
#ifdef BACKLIGHT_PWM_TIMER // pwm through software
// we support multiple backlight pins
# ifndef BACKLIGHT_LED_COUNT
# define BACKLIGHT_LED_COUNT 1
# endif
# ifndef BACKLIGHT_LED_COUNT
# define BACKLIGHT_LED_COUNT 1
# endif
# if BACKLIGHT_LED_COUNT == 1
# define BACKLIGHT_PIN_INIT \
{ BACKLIGHT_PIN }
# else
# define BACKLIGHT_PIN_INIT BACKLIGHT_PINS
# endif
# if BACKLIGHT_LED_COUNT == 1
# define BACKLIGHT_PIN_INIT \
{ BACKLIGHT_PIN }
# else
# define BACKLIGHT_PIN_INIT BACKLIGHT_PINS
# endif
# define FOR_EACH_LED(x) \
for (uint8_t i = 0; i < BACKLIGHT_LED_COUNT; i++) { \
pin_t backlight_pin = backlight_pins[i]; \
{ x } \
}
# define FOR_EACH_LED(x) \
for (uint8_t i = 0; i < BACKLIGHT_LED_COUNT; i++) { \
pin_t backlight_pin = backlight_pins[i]; \
{ x } \
}
static const pin_t backlight_pins[BACKLIGHT_LED_COUNT] = BACKLIGHT_PIN_INIT;
# else // full hardware PWM
#else // full hardware PWM
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
}
// we support only one backlight pin
static const pin_t backlight_pin = BACKLIGHT_PIN;
# define FOR_EACH_LED(x) x
# define FOR_EACH_LED(x) x
# endif
#endif
# ifdef NO_HARDWARE_PWM
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);)
# ifdef BACKLIGHT_BREATHING
if (is_backlight_breathing()) {
breathing_enable();
}
# endif
}
uint8_t backlight_tick = 0;
# ifndef BACKLIGHT_CUSTOM_DRIVER
void backlight_task(void) {
if ((0xFFFF >> ((BACKLIGHT_LEVELS - get_backlight_level()) * ((BACKLIGHT_LEVELS + 1) / 2))) & (1 << backlight_tick)) {
FOR_EACH_LED(backlight_on(backlight_pin);)
} else {
FOR_EACH_LED(backlight_off(backlight_pin);)
}
backlight_tick = (backlight_tick + 1) % 16;
}
# endif
# ifdef BACKLIGHT_BREATHING
# ifndef BACKLIGHT_CUSTOM_DRIVER
# error "Backlight breathing only available with hardware PWM. Please disable."
# endif
# endif
# else // hardware pwm through timer
# ifdef BACKLIGHT_PWM_TIMER
#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
@ -288,11 +251,11 @@ ISR(TIMERx_COMPA_vect) { FOR_EACH_LED(backlight_off(backlight_pin);) }
// Triggered when the counter reaches the TOP value
// this one triggers at F_CPU/65536 =~ 244 Hz
ISR(TIMERx_OVF_vect) {
# ifdef BACKLIGHT_BREATHING
# ifdef BACKLIGHT_BREATHING
if (is_breathing()) {
breathing_task();
}
# endif
# 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
@ -306,9 +269,9 @@ ISR(TIMERx_OVF_vect) {
}
}
# endif
#endif
# define TIMER_TOP 0xFFFFU
#define TIMER_TOP 0xFFFFU
// See http://jared.geek.nz/2013/feb/linear-led-pwm
static uint16_t cie_lightness(uint16_t v) {
@ -329,88 +292,86 @@ static uint16_t cie_lightness(uint16_t v) {
// range for val is [0..TIMER_TOP]. PWM pin is high while the timer count is below val.
static inline void set_pwm(uint16_t val) { OCRxx = val; }
# ifndef BACKLIGHT_CUSTOM_DRIVER
void backlight_set(uint8_t level) {
if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS;
if (level == 0) {
# ifdef BACKLIGHT_PWM_TIMER
#ifdef BACKLIGHT_PWM_TIMER
if (OCRxx) {
TIMSKx &= ~(_BV(OCIExA));
TIMSKx &= ~(_BV(TOIEx));
}
# else
#else
// Turn off PWM control on backlight pin
disable_pwm();
# endif
#endif
FOR_EACH_LED(backlight_off(backlight_pin);)
} else {
# ifdef BACKLIGHT_PWM_TIMER
#ifdef BACKLIGHT_PWM_TIMER
if (!OCRxx) {
TIMSKx |= _BV(OCIExA);
TIMSKx |= _BV(TOIEx);
}
# else
#else
// Turn on PWM control of backlight pin
enable_pwm();
# endif
#endif
}
// Set the brightness
set_pwm(cie_lightness(TIMER_TOP * (uint32_t)level / BACKLIGHT_LEVELS));
}
void backlight_task(void) {}
# endif // BACKLIGHT_CUSTOM_DRIVER
# ifdef BACKLIGHT_BREATHING
#ifdef BACKLIGHT_BREATHING
# define BREATHING_NO_HALT 0
# define BREATHING_HALT_OFF 1
# define BREATHING_HALT_ON 2
# define BREATHING_STEPS 128
# define BREATHING_NO_HALT 0
# define BREATHING_HALT_OFF 1
# define BREATHING_HALT_ON 2
# define BREATHING_STEPS 128
static uint8_t breathing_halt = BREATHING_NO_HALT;
static uint8_t breathing_halt = BREATHING_NO_HALT;
static uint16_t breathing_counter = 0;
# ifdef BACKLIGHT_PWM_TIMER
# 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
# define breathing_interrupt_enable() \
do { \
breathing = true; \
} while (0)
# define breathing_interrupt_disable() \
do { \
breathing = false; \
} while (0)
# else
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)
# endif
# define breathing_min() \
do { \
breathing_counter = 0; \
} while (0)
# define breathing_max() \
do { \
breathing_counter = get_breathing_period() * 244 / 2; \
} while (0)
# define breathing_min() \
do { \
breathing_counter = 0; \
} while (0)
# define breathing_max() \
do { \
breathing_counter = get_breathing_period() * 244 / 2; \
} while (0)
void breathing_enable(void) {
breathing_counter = 0;
breathing_halt = BREATHING_NO_HALT;
breathing_halt = BREATHING_NO_HALT;
breathing_interrupt_enable();
}
@ -451,20 +412,20 @@ static const uint8_t breathing_table[BREATHING_STEPS] PROGMEM = {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(); }
# ifdef BACKLIGHT_PWM_TIMER
# ifdef BACKLIGHT_PWM_TIMER
void breathing_task(void)
# else
# 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.
*/
ISR(TIMERx_OVF_vect)
# endif
# endif
{
uint8_t breathing_period = get_breathing_period();
uint16_t interval = (uint16_t)breathing_period * 244 / BREATHING_STEPS;
uint8_t breathing_period = get_breathing_period();
uint16_t interval = (uint16_t)breathing_period * 244 / BREATHING_STEPS;
// resetting after one period to prevent ugly reset at overflow.
breathing_counter = (breathing_counter + 1) % (breathing_period * 244);
uint8_t index = breathing_counter / interval % BREATHING_STEPS;
uint8_t index = breathing_counter / interval % BREATHING_STEPS;
if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) {
breathing_interrupt_disable();
@ -473,7 +434,7 @@ ISR(TIMERx_OVF_vect)
set_pwm(cie_lightness(scale_backlight((uint16_t)pgm_read_byte(&breathing_table[index]) * 0x0101U)));
}
# endif // BACKLIGHT_BREATHING
#endif // BACKLIGHT_BREATHING
void backlight_init_ports(void) {
// Setup backlight pin as output and output to on state.
@ -483,12 +444,12 @@ void backlight_init_ports(void) {
// 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
#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
#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.)
@ -500,25 +461,21 @@ 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)."
*/
# if BACKLIGHT_ON_STATE == 1
# if BACKLIGHT_ON_STATE == 1
TCCRxA = _BV(COMxx1) | _BV(WGM11);
# else
# else
TCCRxA = _BV(COMxx1) | _BV(COMxx0) | _BV(WGM11);
# endif
# endif
TCCRxB = _BV(WGM13) | _BV(WGM12) | _BV(CS10);
# endif
#endif
// Use full 16-bit resolution. Counter counts to ICR1 before reset to 0.
ICRx = TIMER_TOP;
backlight_init();
# ifdef BACKLIGHT_BREATHING
#ifdef BACKLIGHT_BREATHING
if (is_backlight_breathing()) {
breathing_enable();
}
# endif
#endif
}
# endif // hardware backlight
#endif // backlight