diff options
Diffstat (limited to 'quantum/backlight')
| -rw-r--r-- | quantum/backlight/backlight.c | 194 | ||||
| -rw-r--r-- | quantum/backlight/backlight.h | 4 | ||||
| -rw-r--r-- | quantum/backlight/backlight_arm.c | 218 | ||||
| -rw-r--r-- | quantum/backlight/backlight_avr.c | 509 |
4 files changed, 732 insertions, 193 deletions
diff --git a/quantum/backlight/backlight.c b/quantum/backlight/backlight.c index 708022f68f..e26de86bf9 100644 --- a/quantum/backlight/backlight.c +++ b/quantum/backlight/backlight.c @@ -1,193 +1 @@ -/* -Copyright 2013 Mathias Andersson <wraul@dbox.se> - -This program is free software: you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation, either version 2 of the License, or -(at your option) any later version. - -This program is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with this program. If not, see <http://www.gnu.org/licenses/>. -*/ - -#include "backlight.h" -#include "eeconfig.h" -#include "debug.h" - -backlight_config_t backlight_config; - -/** \brief Backlight initialization - * - * FIXME: needs doc - */ -void backlight_init(void) { - /* check signature */ - if (!eeconfig_is_enabled()) { - eeconfig_init(); - } - backlight_config.raw = eeconfig_read_backlight(); - if (backlight_config.level > BACKLIGHT_LEVELS) { - backlight_config.level = BACKLIGHT_LEVELS; - } - backlight_set(backlight_config.enable ? backlight_config.level : 0); -} - -/** \brief Backlight increase - * - * FIXME: needs doc - */ -void backlight_increase(void) { - if (backlight_config.level < BACKLIGHT_LEVELS) { - backlight_config.level++; - } - backlight_config.enable = 1; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight increase: %u\n", backlight_config.level); - backlight_set(backlight_config.level); -} - -/** \brief Backlight decrease - * - * FIXME: needs doc - */ -void backlight_decrease(void) { - if (backlight_config.level > 0) { - backlight_config.level--; - backlight_config.enable = !!backlight_config.level; - eeconfig_update_backlight(backlight_config.raw); - } - dprintf("backlight decrease: %u\n", backlight_config.level); - backlight_set(backlight_config.level); -} - -/** \brief Backlight toggle - * - * FIXME: needs doc - */ -void backlight_toggle(void) { - bool enabled = backlight_config.enable; - dprintf("backlight toggle: %u\n", enabled); - if (enabled) - backlight_disable(); - else - backlight_enable(); -} - -/** \brief Enable backlight - * - * FIXME: needs doc - */ -void backlight_enable(void) { - if (backlight_config.enable) return; // do nothing if backlight is already on - - backlight_config.enable = true; - if (backlight_config.raw == 1) // enabled but level == 0 - backlight_config.level = 1; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight enable\n"); - backlight_set(backlight_config.level); -} - -/** \brief Disable backlight - * - * FIXME: needs doc - */ -void backlight_disable(void) { - if (!backlight_config.enable) return; // do nothing if backlight is already off - - backlight_config.enable = false; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight disable\n"); - backlight_set(0); -} - -/** /brief Get the backlight status - * - * FIXME: needs doc - */ -bool is_backlight_enabled(void) { return backlight_config.enable; } - -/** \brief Backlight step through levels - * - * FIXME: needs doc - */ -void backlight_step(void) { - backlight_config.level++; - if (backlight_config.level > BACKLIGHT_LEVELS) { - backlight_config.level = 0; - } - backlight_config.enable = !!backlight_config.level; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight step: %u\n", backlight_config.level); - backlight_set(backlight_config.level); -} - -/** \brief Backlight set level - * - * FIXME: needs doc - */ -void backlight_level(uint8_t level) { - if (level > BACKLIGHT_LEVELS) level = BACKLIGHT_LEVELS; - backlight_config.level = level; - backlight_config.enable = !!backlight_config.level; - eeconfig_update_backlight(backlight_config.raw); - backlight_set(backlight_config.level); -} - -/** \brief Get backlight level - * - * FIXME: needs doc - */ -uint8_t get_backlight_level(void) { return backlight_config.level; } - -#ifdef BACKLIGHT_BREATHING -/** \brief Backlight breathing toggle - * - * FIXME: needs doc - */ -void backlight_toggle_breathing(void) { - bool breathing = backlight_config.breathing; - dprintf("backlight breathing toggle: %u\n", breathing); - if (breathing) - backlight_disable_breathing(); - else - backlight_enable_breathing(); -} - -/** \brief Enable backlight breathing - * - * FIXME: needs doc - */ -void backlight_enable_breathing(void) { - if (backlight_config.breathing) return; // do nothing if breathing is already on - - backlight_config.breathing = true; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight breathing enable\n"); - breathing_enable(); -} - -/** \brief Disable backlight breathing - * - * FIXME: needs doc - */ -void backlight_disable_breathing(void) { - if (!backlight_config.breathing) return; // do nothing if breathing is already off - - backlight_config.breathing = false; - eeconfig_update_backlight(backlight_config.raw); - dprintf("backlight breathing disable\n"); - breathing_disable(); -} - -/** \brief Get the backlight breathing status - * - * FIXME: needs doc - */ -bool is_backlight_breathing(void) { return backlight_config.breathing; } -#endif +// TODO: Add common code here, for example cie_lightness implementation diff --git a/quantum/backlight/backlight.h b/quantum/backlight/backlight.h index bb1f897ee8..1e581055db 100644 --- a/quantum/backlight/backlight.h +++ b/quantum/backlight/backlight.h @@ -26,6 +26,10 @@ along with this program. If not, see <http://www.gnu.org/licenses/>. # error "Maximum value of BACKLIGHT_LEVELS is 31" #endif +#ifndef BREATHING_PERIOD +# define BREATHING_PERIOD 6 +#endif + typedef union { uint8_t raw; struct { diff --git a/quantum/backlight/backlight_arm.c b/quantum/backlight/backlight_arm.c new file mode 100644 index 0000000000..3f94ccef8e --- /dev/null +++ b/quantum/backlight/backlight_arm.c @@ -0,0 +1,218 @@ +#include "quantum.h" +#include "backlight.h" +#include <hal.h> +#include "debug.h" + +// TODO: remove short term bodge when refactoring BACKLIGHT_CUSTOM_DRIVER out +#ifdef BACKLIGHT_PIN + +# if defined(STM32F0XX) || defined(STM32F0xx) +# error "Backlight support for STMF072 is not available. Please disable." +# endif + +# if defined(STM32F1XX) || defined(STM32F1xx) +# define USE_GPIOV1 +# endif + +// GPIOV2 && GPIOV3 +# ifndef BACKLIGHT_PAL_MODE +# define BACKLIGHT_PAL_MODE 2 +# endif + +// GENERIC +# ifndef BACKLIGHT_PWM_DRIVER +# define BACKLIGHT_PWM_DRIVER PWMD4 +# endif +# ifndef BACKLIGHT_PWM_CHANNEL +# define BACKLIGHT_PWM_CHANNEL 3 +# endif + +static void breathing_callback(PWMDriver *pwmp); + +static PWMConfig pwmCFG = {0xFFFF, /* PWM clock frequency */ + 256, /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */ + NULL, /* No Callback */ + { /* Default all channels to disabled - Channels will be configured durring init */ + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}}, + 0, /* HW dependent part.*/ + 0}; + +static PWMConfig pwmCFG_breathing = {0xFFFF, /** PWM clock frequency */ + 256, /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */ + breathing_callback, /* Breathing Callback */ + { /* Default all channels to disabled - Channels will be configured durring init */ + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}, + {PWM_OUTPUT_DISABLED, NULL}}, + 0, /* HW dependent part.*/ + 0}; + +// See http://jared.geek.nz/2013/feb/linear-led-pwm +static uint16_t cie_lightness(uint16_t v) { + if (v <= 5243) // if below 8% of max + return v / 9; // same as dividing by 900% + else { + uint32_t y = (((uint32_t)v + 10486) << 8) / (10486 + 0xFFFFUL); // add 16% of max and compare + // to get a useful result with integer division, we shift left in the expression above + // and revert what we've done again after squaring. + y = y * y * y >> 8; + if (y > 0xFFFFUL) // prevent overflow + return 0xFFFFU; + else + return (uint16_t)y; + } +} + +void backlight_init_ports(void) { + // printf("backlight_init_ports()\n"); + +# ifdef USE_GPIOV1 + palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL); +# else + palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_ALTERNATE(BACKLIGHT_PAL_MODE)); +# endif + + pwmCFG.channels[BACKLIGHT_PWM_CHANNEL - 1].mode = PWM_OUTPUT_ACTIVE_HIGH; + pwmCFG_breathing.channels[BACKLIGHT_PWM_CHANNEL - 1].mode = PWM_OUTPUT_ACTIVE_HIGH; + pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG); + + backlight_set(get_backlight_level()); + if (is_backlight_breathing()) { + breathing_enable(); + } +} + +void backlight_set(uint8_t level) { + // printf("backlight_set(%d)\n", level); + if (level == 0) { + // Turn backlight off + pwmDisableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1); + } else { + // Turn backlight on + if (!is_breathing()) { + uint32_t duty = (uint32_t)(cie_lightness(0xFFFF * (uint32_t)level / BACKLIGHT_LEVELS)); + // printf("duty: (%d)\n", duty); + pwmEnableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty)); + } + } +} + +uint8_t backlight_tick = 0; + +void backlight_task(void) {} + +# define BREATHING_NO_HALT 0 +# define BREATHING_HALT_OFF 1 +# define BREATHING_HALT_ON 2 +# define BREATHING_STEPS 128 + +static uint8_t breathing_period = BREATHING_PERIOD; +static uint8_t breathing_halt = BREATHING_NO_HALT; +static uint16_t breathing_counter = 0; + +bool is_breathing(void) { return BACKLIGHT_PWM_DRIVER.config == &pwmCFG_breathing; } + +static inline void breathing_min(void) { breathing_counter = 0; } + +static inline void breathing_max(void) { breathing_counter = breathing_period * 256 / 2; } + +void breathing_interrupt_enable(void) { + pwmStop(&BACKLIGHT_PWM_DRIVER); + pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG_breathing); + chSysLockFromISR(); + pwmEnablePeriodicNotification(&BACKLIGHT_PWM_DRIVER); + pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, 0xFFFF)); + chSysUnlockFromISR(); +} + +void breathing_interrupt_disable(void) { + pwmStop(&BACKLIGHT_PWM_DRIVER); + pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG); +} + +void breathing_enable(void) { + breathing_counter = 0; + breathing_halt = BREATHING_NO_HALT; + breathing_interrupt_enable(); +} + +void breathing_pulse(void) { + if (get_backlight_level() == 0) + breathing_min(); + else + breathing_max(); + breathing_halt = BREATHING_HALT_ON; + breathing_interrupt_enable(); +} + +void breathing_disable(void) { + // printf("breathing_disable()\n"); + breathing_interrupt_disable(); + // Restore backlight level + backlight_set(get_backlight_level()); +} + +void breathing_self_disable(void) { + if (get_backlight_level() == 0) + breathing_halt = BREATHING_HALT_OFF; + else + breathing_halt = BREATHING_HALT_ON; +} + +void breathing_toggle(void) { + if (is_breathing()) + breathing_disable(); + else + breathing_enable(); +} + +void breathing_period_set(uint8_t value) { + if (!value) value = 1; + breathing_period = value; +} + +void breathing_period_default(void) { breathing_period_set(BREATHING_PERIOD); } + +void breathing_period_inc(void) { breathing_period_set(breathing_period + 1); } + +void breathing_period_dec(void) { breathing_period_set(breathing_period - 1); } + +/* To generate breathing curve in python: + * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)] + */ +static const uint8_t breathing_table[BREATHING_STEPS] = {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 void breathing_callback(PWMDriver *pwmp) { + (void)pwmp; + uint16_t interval = (uint16_t)breathing_period * 256 / BREATHING_STEPS; + // resetting after one period to prevent ugly reset at overflow. + breathing_counter = (breathing_counter + 1) % (breathing_period * 256); + 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(); + } + + uint32_t duty = cie_lightness(scale_backlight(breathing_table[index] * 256)); + + chSysLockFromISR(); + pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty)); + chSysUnlockFromISR(); +} + +#else + +__attribute__((weak)) void backlight_init_ports(void) {} + +__attribute__((weak)) void backlight_set(uint8_t level) {} + +__attribute__((weak)) void backlight_task(void) {} + +#endif diff --git a/quantum/backlight/backlight_avr.c b/quantum/backlight/backlight_avr.c new file mode 100644 index 0000000000..445698f47c --- /dev/null +++ b/quantum/backlight/backlight_avr.c @@ -0,0 +1,509 @@ +#include "quantum.h" +#include "backlight.h" +#include "debug.h" + +#if defined(BACKLIGHT_ENABLE) && (defined(BACKLIGHT_PIN) || defined(BACKLIGHT_PINS)) + +// 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 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 COMxx1 COM1A1 +# define OCRxx OCR1A +# elif BACKLIGHT_PIN == B6 +# define COMxx1 COM1B1 +# define OCRxx OCR1B +# elif BACKLIGHT_PIN == B7 +# 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 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 COMxx1 COM3B1 +# define OCRxx OCR3B +# endif +# elif BACKLIGHT_PIN == C6 +# 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 COMxx1 COM1C1 +# define OCRxx OCR1C +# elif BACKLIGHT_PIN == C5 +# define COMxx1 COM1B1 +# define OCRxx OCR1B +# elif BACKLIGHT_PIN == C6 +# 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 COMxx1 COM1B1 +# define OCRxx OCR1B +# elif BACKLIGHT_PIN == D5 +# 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 COMxx1 COM1A1 +# define OCRxx OCR1A +# elif BACKLIGHT_PIN == B2 +# 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 +# else +# pragma message "Custom driver defined - using pure software PWM" +# define NO_HARDWARE_PWM +# endif +# endif + +# ifndef BACKLIGHT_ON_STATE +# define BACKLIGHT_ON_STATE 0 +# endif + +void backlight_on(uint8_t backlight_pin) { +# if BACKLIGHT_ON_STATE == 0 + writePinLow(backlight_pin); +# else + writePinHigh(backlight_pin); +# endif +} + +void backlight_off(uint8_t backlight_pin) { +# if BACKLIGHT_ON_STATE == 0 + writePinHigh(backlight_pin); +# else + writePinLow(backlight_pin); +# endif +} + +# if defined(NO_HARDWARE_PWM) || defined(BACKLIGHT_PWM_TIMER) // pwm through software + +// we support multiple backlight pins +# 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 + +# define FOR_EACH_LED(x) \ + for (uint8_t i = 0; i < BACKLIGHT_LED_COUNT; i++) { \ + uint8_t backlight_pin = backlight_pins[i]; \ + { x } \ + } + +static const uint8_t backlight_pins[BACKLIGHT_LED_COUNT] = BACKLIGHT_PIN_INIT; + +# else // full hardware PWM + +// we support only one backlight pin +static const uint8_t backlight_pin = BACKLIGHT_PIN; +# define FOR_EACH_LED(x) x + +# endif + +# ifdef NO_HARDWARE_PWM +__attribute__((weak)) 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 +} + +__attribute__((weak)) void backlight_set(uint8_t level) {} + +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 + +// 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. + +// Triggered when the counter reaches the OCRx value +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 + 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 > 256) { + FOR_EACH_LED(backlight_on(backlight_pin);) + } +} + +# 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 <= 5243) // if below 8% of max + return v / 9; // same as dividing by 900% + else { + uint32_t y = (((uint32_t)v + 10486) << 8) / (10486 + 0xFFFFUL); // add 16% of max and compare + // to get a useful result with integer division, we shift left in the expression above + // and revert what we've done again after squaring. + y = y * y * y >> 8; + if (y > 0xFFFFUL) // prevent overflow + return 0xFFFFU; + else + return (uint16_t)y; + } +} + +// 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 +__attribute__((weak)) 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)); + FOR_EACH_LED(backlight_off(backlight_pin);) + } +# else + // Turn off PWM control on backlight pin + TCCRxA &= ~(_BV(COMxx1)); +# endif + } else { +# ifdef BACKLIGHT_PWM_TIMER + if (!OCRxx) { + TIMSKx |= _BV(OCIExA); + TIMSKx |= _BV(TOIEx); + } +# else + // Turn on PWM control of backlight pin + TCCRxA |= _BV(COMxx1); +# 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 + +# define BREATHING_NO_HALT 0 +# define BREATHING_HALT_OFF 1 +# define BREATHING_HALT_ON 2 +# define BREATHING_STEPS 128 + +static uint8_t breathing_period = BREATHING_PERIOD; +static uint8_t breathing_halt = BREATHING_NO_HALT; +static uint16_t breathing_counter = 0; + +# 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 + +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_min() \ + do { \ + breathing_counter = 0; \ + } while (0) +# define breathing_max() \ + do { \ + breathing_counter = breathing_period * 244 / 2; \ + } while (0) + +void breathing_enable(void) { + breathing_counter = 0; + breathing_halt = BREATHING_NO_HALT; + breathing_interrupt_enable(); +} + +void breathing_pulse(void) { + if (get_backlight_level() == 0) + breathing_min(); + else + breathing_max(); + breathing_halt = BREATHING_HALT_ON; + breathing_interrupt_enable(); +} + +void breathing_disable(void) { + breathing_interrupt_disable(); + // Restore backlight level + backlight_set(get_backlight_level()); +} + +void breathing_self_disable(void) { + if (get_backlight_level() == 0) + breathing_halt = BREATHING_HALT_OFF; + else + breathing_halt = BREATHING_HALT_ON; +} + +void breathing_toggle(void) { + if (is_breathing()) + breathing_disable(); + else + breathing_enable(); +} + +void breathing_period_set(uint8_t value) { + if (!value) value = 1; + breathing_period = value; +} + +void breathing_period_default(void) { breathing_period_set(BREATHING_PERIOD); } + +void breathing_period_inc(void) { breathing_period_set(breathing_period + 1); } + +void breathing_period_dec(void) { breathing_period_set(breathing_period - 1); } + +/* To generate breathing curve in python: + * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)] + */ +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(); } + +# 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. + */ +ISR(TIMERx_OVF_vect) +# endif +{ + 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; + + if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) { + breathing_interrupt_disable(); + } + + set_pwm(cie_lightness(scale_backlight((uint16_t)pgm_read_byte(&breathing_table[index]) * 0x0101U))); +} + +# endif // BACKLIGHT_BREATHING + +__attribute__((weak)) 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);) + + // 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.) + // WGM Mode 14 (Fast PWM) = WGM13=1 WGM12=1 WGM11=1 WGM10=0 + // Clock Select = clk/1 (no prescaling) = CS12=0 CS11=0 CS10=1 + + /* + 14.8.3: + "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; +# endif + // Use full 16-bit resolution. Counter counts to ICR1 before reset to 0. + ICRx = TIMER_TOP; + + backlight_init(); +# ifdef BACKLIGHT_BREATHING + if (is_backlight_breathing()) { + breathing_enable(); + } +# endif +} + +# endif // hardware backlight + +#else // no backlight + +__attribute__((weak)) void backlight_init_ports(void) {} + +__attribute__((weak)) void backlight_set(uint8_t level) {} + +#endif // backlight
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