quantum/backlight/backlight_arm.c

   1 #include "quantum.h"
   2 #include "backlight.h"
   3 #include <hal.h>
   4 #include "debug.h"
   5
   6 // TODO: remove short term bodge when refactoring BACKLIGHT_CUSTOM_DRIVER out
   7 #ifdef BACKLIGHT_PIN
   8
   9 #    if defined(STM32F0XX) || defined(STM32F0xx)
  10 #        error "Backlight support for STMF072 is not available. Please disable."
  11 #    endif
  12
  13 // GPIOV2 && GPIOV3
  14 #    ifndef BACKLIGHT_PAL_MODE
  15 #        define BACKLIGHT_PAL_MODE 2
  16 #    endif
  17
  18 // GENERIC
  19 #    ifndef BACKLIGHT_PWM_DRIVER
  20 #        define BACKLIGHT_PWM_DRIVER PWMD4
  21 #    endif
  22 #    ifndef BACKLIGHT_PWM_CHANNEL
  23 #        define BACKLIGHT_PWM_CHANNEL 3
  24 #    endif
  25
  26 static void breathing_callback(PWMDriver *pwmp);
  27
  28 static PWMConfig pwmCFG = {0xFFFF, /* PWM clock frequency  */
  29                            256,    /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */
  30                            NULL,   /* No Callback */
  31                            {       /* Default all channels to disabled - Channels will be configured durring init */
  32                             {PWM_OUTPUT_DISABLED, NULL},
  33                             {PWM_OUTPUT_DISABLED, NULL},
  34                             {PWM_OUTPUT_DISABLED, NULL},
  35                             {PWM_OUTPUT_DISABLED, NULL}},
  36                            0, /* HW dependent part.*/
  37                            0};
  38
  39 static PWMConfig pwmCFG_breathing = {0xFFFF,             /** PWM clock frequency  */
  40                                      256,                /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */
  41                                      breathing_callback, /* Breathing Callback */
  42                                      {                   /* Default all channels to disabled - Channels will be configured durring init */
  43                                       {PWM_OUTPUT_DISABLED, NULL},
  44                                       {PWM_OUTPUT_DISABLED, NULL},
  45                                       {PWM_OUTPUT_DISABLED, NULL},
  46                                       {PWM_OUTPUT_DISABLED, NULL}},
  47                                      0, /* HW dependent part.*/
  48                                      0};
  49
  50 // See http://jared.geek.nz/2013/feb/linear-led-pwm
  51 static uint16_t cie_lightness(uint16_t v) {
  52     if (v <= 5243)     // if below 8% of max
  53         return v / 9;  // same as dividing by 900%
  54     else {
  55         uint32_t y = (((uint32_t)v + 10486) << 8) / (10486 + 0xFFFFUL);  // add 16% of max and compare
  56         // to get a useful result with integer division, we shift left in the expression above
  57         // and revert what we've done again after squaring.
  58         y = y * y * y >> 8;
  59         if (y > 0xFFFFUL)  // prevent overflow
  60             return 0xFFFFU;
  61         else
  62             return (uint16_t)y;
  63     }
  64 }
  65
  66 void backlight_init_ports(void) {
  67     // printf("backlight_init_ports()\n");
  68
  69 #    ifdef USE_GPIOV1
  70     palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL);
  71 #    else
  72     palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_ALTERNATE(BACKLIGHT_PAL_MODE));
  73 #    endif
  74
  75     pwmCFG.channels[BACKLIGHT_PWM_CHANNEL - 1].mode           = PWM_OUTPUT_ACTIVE_HIGH;
  76     pwmCFG_breathing.channels[BACKLIGHT_PWM_CHANNEL - 1].mode = PWM_OUTPUT_ACTIVE_HIGH;
  77     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG);
  78
  79     backlight_set(get_backlight_level());
  80     if (is_backlight_breathing()) {
  81         breathing_enable();
  82     }
  83 }
  84
  85 void backlight_set(uint8_t level) {
  86     // printf("backlight_set(%d)\n", level);
  87     if (level == 0) {
  88         // Turn backlight off
  89         pwmDisableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1);
  90     } else {
  91         // Turn backlight on
  92         if (!is_breathing()) {
  93             uint32_t duty = (uint32_t)(cie_lightness(0xFFFF * (uint32_t)level / BACKLIGHT_LEVELS));
  94             // printf("duty: (%d)\n", duty);
  95             pwmEnableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty));
  96         }
  97     }
  98 }
  99
 100 uint8_t backlight_tick = 0;
 101
 102 void backlight_task(void) {}
 103
 104 #    define BREATHING_NO_HALT 0
 105 #    define BREATHING_HALT_OFF 1
 106 #    define BREATHING_HALT_ON 2
 107 #    define BREATHING_STEPS 128
 108
 109 static uint8_t  breathing_period  = BREATHING_PERIOD;
 110 static uint8_t  breathing_halt    = BREATHING_NO_HALT;
 111 static uint16_t breathing_counter = 0;
 112
 113 bool is_breathing(void) { return BACKLIGHT_PWM_DRIVER.config == &pwmCFG_breathing; }
 114
 115 static inline void breathing_min(void) { breathing_counter = 0; }
 116
 117 static inline void breathing_max(void) { breathing_counter = breathing_period * 256 / 2; }
 118
 119 void breathing_interrupt_enable(void) {
 120     pwmStop(&BACKLIGHT_PWM_DRIVER);
 121     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG_breathing);
 122     chSysLockFromISR();
 123     pwmEnablePeriodicNotification(&BACKLIGHT_PWM_DRIVER);
 124     pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, 0xFFFF));
 125     chSysUnlockFromISR();
 126 }
 127
 128 void breathing_interrupt_disable(void) {
 129     pwmStop(&BACKLIGHT_PWM_DRIVER);
 130     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG);
 131 }
 132
 133 void breathing_enable(void) {
 134     breathing_counter = 0;
 135     breathing_halt    = BREATHING_NO_HALT;
 136     breathing_interrupt_enable();
 137 }
 138
 139 void breathing_pulse(void) {
 140     if (get_backlight_level() == 0)
 141         breathing_min();
 142     else
 143         breathing_max();
 144     breathing_halt = BREATHING_HALT_ON;
 145     breathing_interrupt_enable();
 146 }
 147
 148 void breathing_disable(void) {
 149     // printf("breathing_disable()\n");
 150     breathing_interrupt_disable();
 151     // Restore backlight level
 152     backlight_set(get_backlight_level());
 153 }
 154
 155 void breathing_self_disable(void) {
 156     if (get_backlight_level() == 0)
 157         breathing_halt = BREATHING_HALT_OFF;
 158     else
 159         breathing_halt = BREATHING_HALT_ON;
 160 }
 161
 162 void breathing_toggle(void) {
 163     if (is_breathing())
 164         breathing_disable();
 165     else
 166         breathing_enable();
 167 }
 168
 169 void breathing_period_set(uint8_t value) {
 170     if (!value) value = 1;
 171     breathing_period = value;
 172 }
 173
 174 void breathing_period_default(void) { breathing_period_set(BREATHING_PERIOD); }
 175
 176 void breathing_period_inc(void) { breathing_period_set(breathing_period + 1); }
 177
 178 void breathing_period_dec(void) { breathing_period_set(breathing_period - 1); }
 179
 180 /* To generate breathing curve in python:
 181  * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)]
 182  */
 183 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};
 184
 185 // Use this before the cie_lightness function.
 186 static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); }
 187
 188 static void breathing_callback(PWMDriver *pwmp) {
 189     (void)pwmp;
 190     uint16_t interval = (uint16_t)breathing_period * 256 / BREATHING_STEPS;
 191     // resetting after one period to prevent ugly reset at overflow.
 192     breathing_counter = (breathing_counter + 1) % (breathing_period * 256);
 193     uint8_t index     = breathing_counter / interval % BREATHING_STEPS;
 194
 195     if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) {
 196         breathing_interrupt_disable();
 197     }
 198
 199     uint32_t duty = cie_lightness(scale_backlight(breathing_table[index] * 256));
 200
 201     chSysLockFromISR();
 202     pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty));
 203     chSysUnlockFromISR();
 204 }
 205
 206 #else
 207
 208 __attribute__((weak)) void backlight_init_ports(void) {}
 209
 210 __attribute__((weak)) void backlight_set(uint8_t level) {}
 211
 212 __attribute__((weak)) void backlight_task(void) {}
 213
 214 #endif