1 files changed, 213 insertions, 7 deletions

diff --git a/keyboards/handwired/practice60/led.c b/keyboards/handwired/practice60/led.c
index f15baed16..a9ede5bba 100644
--- a/keyboards/handwired/practice60/led.c
+++ b/keyboards/handwired/practice60/led.c
@@ -18,34 +18,240 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "hal.h"
 #include "backlight.h"
 #include "led.h"
+#include "led_custom.h"
 #include "printf.h"
 
+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 */
+  {
+      {PWM_OUTPUT_ACTIVE_HIGH, NULL}, /* Enable Channel 0 */
+      {PWM_OUTPUT_DISABLED, NULL},
+      {PWM_OUTPUT_DISABLED, NULL},
+      {PWM_OUTPUT_DISABLED, NULL}
+  },
+  0,                                  /* HW dependent part.*/
+  0
+};
+
+static PWMConfig pwmCFG_breathing = {
+  0xFFFF,                              /* 10kHz PWM clock frequency  */
+  256,                              /* PWM period (in ticks) 1S (1/10kHz=0.1mS 0.1ms*10000 ticks=1S) */
+  breathing_callback,                               /* Breathing Callback */
+  {
+      {PWM_OUTPUT_ACTIVE_HIGH, NULL}, /* Enable Channel 0 */
+      {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 BACKLIGHT_ENABLE
-    palSetPadMode(GPIOA, 8, PAL_MODE_OUTPUT_PUSHPULL);
-    palSetPad(GPIOA, 8);
+
+    palSetPadMode(GPIOA, 8, PAL_MODE_STM32_ALTERNATE_PUSHPULL);
+    pwmStart(&PWMD1, &pwmCFG);
+    pwmEnableChannel(&PWMD1, 0, PWM_FRACTION_TO_WIDTH(&PWMD1, 0xFFFF,cie_lightness(0xFFFF)));
     #endif
 }
 
 void backlight_set(uint8_t level) {
     printf("backlight_set(%d)\n", level);
     #ifdef BACKLIGHT_ENABLE
+    uint32_t duty = (uint32_t)(cie_lightness(0xFFFF * (uint32_t) level / BACKLIGHT_LEVELS));
+    printf("duty: (%d)\n", duty);
     if (level == 0) {
         // Turn backlight off
-        palSetPad(GPIOA, 8);
+        pwmDisableChannel(&PWMD1, 0);
     } else {
-        // Turn backlight on
-        palClearPad(GPIOA, 8);
+      // Turn backlight on
+      if(!is_breathing()){
+        pwmEnableChannel(&PWMD1, 0, PWM_FRACTION_TO_WIDTH(&PWMD1,0xFFFF,duty));
+      }
     }
     #endif
 }
 
+
+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 PWMD1.config == &pwmCFG_breathing;
+}
+
+#define breathing_min() do {breathing_counter = 0;} while (0)
+#define breathing_max() do {breathing_counter = breathing_period * 256 / 2;} while (0)
+
+
+void breathing_interrupt_enable(void){
+    pwmStop(&PWMD1);
+    printf("starting with callback\n");
+    pwmStart(&PWMD1, &pwmCFG_breathing);
+    chSysLockFromISR();
+    pwmEnablePeriodicNotification(&PWMD1);
+    pwmEnableChannelI(
+      &PWMD1,
+      0,
+      PWM_FRACTION_TO_WIDTH(
+        &PWMD1,
+        0xFFFF,
+        0xFFFF
+      )
+    );
+    chSysUnlockFromISR();
+}
+
+void breathing_interrupt_disable(void){
+    pwmStop(&PWMD1);
+    printf("starting without callback\n");
+    pwmStart(&PWMD1, &pwmCFG);
+}
+
+void breathing_enable(void)
+{
+  printf("breathing_enable()\n");
+  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()){
+    printf("disable breathing\n");
+    breathing_disable();
+  } else {
+    printf("enable breathing\n");
+    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(
+    &PWMD1,
+    0,
+    PWM_FRACTION_TO_WIDTH(
+      &PWMD1,
+      0xFFFF,
+      duty
+    )
+  );
+  chSysUnlockFromISR();
+}
+
+
 void led_set(uint8_t usb_led)
 {
     if (usb_led & (1<<USB_LED_CAPS_LOCK)) {
-        palClearPad(GPIOC, 13);
+      palSetPad(GPIOC, 13);
     } else {
-        palSetPad(GPIOC, 13);
+        palClearPad(GPIOC, 13);
     }
 }