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 #    if defined(STM32F1XX) || defined(STM32F1xx)
  14 #        define USE_GPIOV1
  15 #    endif
  16
  17 // GPIOV2 && GPIOV3
  18 #    ifndef BACKLIGHT_PAL_MODE
  19 #        define BACKLIGHT_PAL_MODE 2
  20 #    endif
  21
  22 // GENERIC
  23 #    ifndef BACKLIGHT_PWM_DRIVER
  24 #        define BACKLIGHT_PWM_DRIVER PWMD4
  25 #    endif
  26 #    ifndef BACKLIGHT_PWM_CHANNEL
  27 #        define BACKLIGHT_PWM_CHANNEL 3
  28 #    endif
  29
  30 static void breathing_callback(PWMDriver *pwmp);
  31
  32 static PWMConfig pwmCFG = {0xFFFF, /* PWM clock frequency  */
  33                            256,    /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */
  34                            NULL,   /* No Callback */
  35                            {       /* Default all channels to disabled - Channels will be configured durring init */
  36                             {PWM_OUTPUT_DISABLED, NULL},
  37                             {PWM_OUTPUT_DISABLED, NULL},
  38                             {PWM_OUTPUT_DISABLED, NULL},
  39                             {PWM_OUTPUT_DISABLED, NULL}},
  40                            0, /* HW dependent part.*/
  41                            0};
  42
  43 static PWMConfig pwmCFG_breathing = {0xFFFF,             /** PWM clock frequency  */
  44                                      256,                /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */
  45                                      breathing_callback, /* Breathing Callback */
  46                                      {                   /* Default all channels to disabled - Channels will be configured durring init */
  47                                       {PWM_OUTPUT_DISABLED, NULL},
  48                                       {PWM_OUTPUT_DISABLED, NULL},
  49                                       {PWM_OUTPUT_DISABLED, NULL},
  50                                       {PWM_OUTPUT_DISABLED, NULL}},
  51                                      0, /* HW dependent part.*/
  52                                      0};
  53
  54 // See http://jared.geek.nz/2013/feb/linear-led-pwm
  55 static uint16_t cie_lightness(uint16_t v) {
  56     if (v <= 5243)     // if below 8% of max
  57         return v / 9;  // same as dividing by 900%
  58     else {
  59         uint32_t y = (((uint32_t)v + 10486) << 8) / (10486 + 0xFFFFUL);  // add 16% of max and compare
  60         // to get a useful result with integer division, we shift left in the expression above
  61         // and revert what we've done again after squaring.
  62         y = y * y * y >> 8;
  63         if (y > 0xFFFFUL)  // prevent overflow
  64             return 0xFFFFU;
  65         else
  66             return (uint16_t)y;
  67     }
  68 }
  69
  70 void backlight_init_ports(void) {
  71     // printf("backlight_init_ports()\n");
  72
  73 #    ifdef USE_GPIOV1
  74     palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_STM32_ALTERNATE_PUSHPULL);
  75 #    else
  76     palSetPadMode(PAL_PORT(BACKLIGHT_PIN), PAL_PAD(BACKLIGHT_PIN), PAL_MODE_ALTERNATE(BACKLIGHT_PAL_MODE));
  77 #    endif
  78
  79     pwmCFG.channels[BACKLIGHT_PWM_CHANNEL - 1].mode           = PWM_OUTPUT_ACTIVE_HIGH;
  80     pwmCFG_breathing.channels[BACKLIGHT_PWM_CHANNEL - 1].mode = PWM_OUTPUT_ACTIVE_HIGH;
  81     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG);
  82
  83     backlight_set(get_backlight_level());
  84     if (is_backlight_breathing()) {
  85         breathing_enable();
  86     }
  87 }
  88
  89 void backlight_set(uint8_t level) {
  90     // printf("backlight_set(%d)\n", level);
  91     if (level == 0) {
  92         // Turn backlight off
  93         pwmDisableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1);
  94     } else {
  95         // Turn backlight on
  96         if (!is_breathing()) {
  97             uint32_t duty = (uint32_t)(cie_lightness(0xFFFF * (uint32_t)level / BACKLIGHT_LEVELS));
  98             // printf("duty: (%d)\n", duty);
  99             pwmEnableChannel(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty));
 100         }
 101     }
 102 }
 103
 104 uint8_t backlight_tick = 0;
 105
 106 void backlight_task(void) {}
 107
 108 #    define BREATHING_NO_HALT 0
 109 #    define BREATHING_HALT_OFF 1
 110 #    define BREATHING_HALT_ON 2
 111 #    define BREATHING_STEPS 128
 112
 113 static uint8_t  breathing_period  = BREATHING_PERIOD;
 114 static uint8_t  breathing_halt    = BREATHING_NO_HALT;
 115 static uint16_t breathing_counter = 0;
 116
 117 bool is_breathing(void) { return BACKLIGHT_PWM_DRIVER.config == &pwmCFG_breathing; }
 118
 119 static inline void breathing_min(void) { breathing_counter = 0; }
 120
 121 static inline void breathing_max(void) { breathing_counter = breathing_period * 256 / 2; }
 122
 123 void breathing_interrupt_enable(void) {
 124     pwmStop(&BACKLIGHT_PWM_DRIVER);
 125     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG_breathing);
 126     chSysLockFromISR();
 127     pwmEnablePeriodicNotification(&BACKLIGHT_PWM_DRIVER);
 128     pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, 0xFFFF));
 129     chSysUnlockFromISR();
 130 }
 131
 132 void breathing_interrupt_disable(void) {
 133     pwmStop(&BACKLIGHT_PWM_DRIVER);
 134     pwmStart(&BACKLIGHT_PWM_DRIVER, &pwmCFG);
 135 }
 136
 137 void breathing_enable(void) {
 138     breathing_counter = 0;
 139     breathing_halt    = BREATHING_NO_HALT;
 140     breathing_interrupt_enable();
 141 }
 142
 143 void breathing_pulse(void) {
 144     if (get_backlight_level() == 0)
 145         breathing_min();
 146     else
 147         breathing_max();
 148     breathing_halt = BREATHING_HALT_ON;
 149     breathing_interrupt_enable();
 150 }
 151
 152 void breathing_disable(void) {
 153     // printf("breathing_disable()\n");
 154     breathing_interrupt_disable();
 155     // Restore backlight level
 156     backlight_set(get_backlight_level());
 157 }
 158
 159 void breathing_self_disable(void) {
 160     if (get_backlight_level() == 0)
 161         breathing_halt = BREATHING_HALT_OFF;
 162     else
 163         breathing_halt = BREATHING_HALT_ON;
 164 }
 165
 166 void breathing_toggle(void) {
 167     if (is_breathing())
 168         breathing_disable();
 169     else
 170         breathing_enable();
 171 }
 172
 173 void breathing_period_set(uint8_t value) {
 174     if (!value) value = 1;
 175     breathing_period = value;
 176 }
 177
 178 void breathing_period_default(void) { breathing_period_set(BREATHING_PERIOD); }
 179
 180 void breathing_period_inc(void) { breathing_period_set(breathing_period + 1); }
 181
 182 void breathing_period_dec(void) { breathing_period_set(breathing_period - 1); }
 183
 184 /* To generate breathing curve in python:
 185  * from math import sin, pi; [int(sin(x/128.0*pi)**4*255) for x in range(128)]
 186  */
 187 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};
 188
 189 // Use this before the cie_lightness function.
 190 static inline uint16_t scale_backlight(uint16_t v) { return v / BACKLIGHT_LEVELS * get_backlight_level(); }
 191
 192 static void breathing_callback(PWMDriver *pwmp) {
 193     (void)pwmp;
 194     uint16_t interval = (uint16_t)breathing_period * 256 / BREATHING_STEPS;
 195     // resetting after one period to prevent ugly reset at overflow.
 196     breathing_counter = (breathing_counter + 1) % (breathing_period * 256);
 197     uint8_t index     = breathing_counter / interval % BREATHING_STEPS;
 198
 199     if (((breathing_halt == BREATHING_HALT_ON) && (index == BREATHING_STEPS / 2)) || ((breathing_halt == BREATHING_HALT_OFF) && (index == BREATHING_STEPS - 1))) {
 200         breathing_interrupt_disable();
 201     }
 202
 203     uint32_t duty = cie_lightness(scale_backlight(breathing_table[index] * 256));
 204
 205     chSysLockFromISR();
 206     pwmEnableChannelI(&BACKLIGHT_PWM_DRIVER, BACKLIGHT_PWM_CHANNEL - 1, PWM_FRACTION_TO_WIDTH(&BACKLIGHT_PWM_DRIVER, 0xFFFF, duty));
 207     chSysUnlockFromISR();
 208 }
 209
 210 #else
 211
 212 __attribute__((weak)) void backlight_init_ports(void) {}
 213
 214 __attribute__((weak)) void backlight_set(uint8_t level) {}
 215
 216 __attribute__((weak)) void backlight_task(void) {}
 217
 218 #endif