Fix SAMD

RTC needed to wait for sync. NeoPixel on SAMD doesn't need disabled
caches. It just needed timing adjustment for 120mhz clock speed.

Author: tannewt

main.c

@@ -485,11 +485,10 @@ STATIC bool run_code_py(safe_mode_t safe_mode) {
                 time_to_next_change = MIN(time_to_next_change, time_to_epaper_refresh);
             }
             #endif
-            if (time_to_next_change > 0) {
-                // time_to_next_change is in ms and ticks are slightly shorter so
-                // we'll undersleep just a little. It shouldn't matter.
-                port_interrupt_after_ticks(time_to_next_change);
-            }
+
+            // time_to_next_change is in ms and ticks are slightly shorter so
+            // we'll undersleep just a little. It shouldn't matter.
+            port_interrupt_after_ticks(time_to_next_change);
             #endif
             port_idle_until_interrupt();
         }

ports/atmel-samd/boards/feather_m4_express/mpconfigboard.h

@@ -12,7 +12,7 @@
 // QSPI Data pins
 #define MICROPY_PORT_A (PORT_PA08 | PORT_PA09 | PORT_PA10 | PORT_PA11)
 // QSPI CS, QSPI SCK and NeoPixel pin
-#define MICROPY_PORT_B (PORT_PB03 | PORT_PB10 | PORT_PB11)
+#define MICROPY_PORT_B (PORT_PB10 | PORT_PB11)
 #define MICROPY_PORT_C (0)
 #define MICROPY_PORT_D (0)
 

ports/atmel-samd/common-hal/neopixel_write/__init__.c

@@ -60,7 +60,7 @@ static void neopixel_send_buffer_core(volatile uint32_t *clraddr, uint32_t pinMa
         "        movs r6, #3; d2: sub r6, #1; bne d2;"          // delay 3
         #endif
         #ifdef SAM_D5X_E5X
-        "        movs r6, #3; d2: subs r6, #1; bne d2;"          // delay 3
+        "        movs r6, #16; d2: subs r6, #1; bne d2;"          // delay 3
         #endif
         "        tst r4, r5;"                                   // mask&r5
         "        bne skipclr;"
@@ -70,7 +70,7 @@ static void neopixel_send_buffer_core(volatile uint32_t *clraddr, uint32_t pinMa
         "        movs r6, #6; d0: sub r6, #1; bne d0;"          // delay 6
         #endif
         #ifdef SAM_D5X_E5X
-        "        movs r6, #6; d0: subs r6, #1; bne d0;"          // delay 6
+        "        movs r6, #16; d0: subs r6, #1; bne d0;"          // delay 6
         #endif
         "        str r1, [r0, #0];"            // clr (possibly again, doesn't matter)
         #ifdef SAMD21
@@ -85,10 +85,13 @@ static void neopixel_send_buffer_core(volatile uint32_t *clraddr, uint32_t pinMa
         "        movs r6, #2; d1: sub r6, #1; bne d1;"          // delay 2
         #endif
         #ifdef SAM_D5X_E5X
-        "        movs r6, #2; d1: subs r6, #1; bne d1;"          // delay 2
+        "        movs r6, #15; d1: subs r6, #1; bne d1;"          // delay 2
         #endif
         "        b       loopBit;"
         "nextbyte:"
+        #ifdef SAM_D5X_E5X
+        "        movs r6, #12; d3: subs r6, #1; bne d3;"          // delay 2
+        #endif
         "        cmp r2, r3;"
         "        bcs neopixel_stop;"
         "        b loopLoad;"
@@ -114,42 +117,12 @@ void common_hal_neopixel_write(const digitalio_digitalinout_obj_t *digitalinout,
     // Turn off interrupts of any kind during timing-sensitive code.
     mp_hal_disable_all_interrupts();
 
-
-    #ifdef SAM_D5X_E5X
-    // When this routine is positioned at certain addresses, the timing logic
-    // below can be too fast by about 2.5x. This is some kind of (un)fortunate code
-    // positioning with respect to a cache line.
-    // Theoretically we should turn on off the CMCC caches and the
-    // NVM caches to ensure consistent timing. Testing shows the the NVMCTRL
-    // cache disabling seems to make the difference. But turn both off to make sure.
-    // It's difficult to test because additions to the code before the timing loop
-    // below change instruction placement. (though this should be less true now that
-    // the main code is in the cache-aligned function neopixel_send_buffer_core)
-    // Testing was done by adding cache changes below the loop (so only the
-    // first time through is wrong).
-    //
-    // Turn off instruction, data, and NVM caches to force consistent timing.
-    // Invalidate existing cache entries.
-    hri_cmcc_set_CFG_reg(CMCC, CMCC_CFG_DCDIS | CMCC_CFG_ICDIS);
-    hri_cmcc_write_MAINT0_reg(CMCC, CMCC_MAINT0_INVALL);
-    hri_nvmctrl_set_CTRLA_CACHEDIS0_bit(NVMCTRL);
-    hri_nvmctrl_set_CTRLA_CACHEDIS1_bit(NVMCTRL);
-    #endif
-
     uint32_t pin = digitalinout->pin->number;
     port = &PORT->Group[GPIO_PORT(pin)];      // Convert GPIO # to port register
     pinMask = (1UL << (pin % 32));   // From port_pin_set_output_level ASF code.
     volatile uint32_t *clr = &(port->OUTCLR.reg);
     neopixel_send_buffer_core(clr, pinMask, pixels, numBytes);
 
-    #ifdef SAM_D5X_E5X
-    // Turn instruction, data, and NVM caches back on.
-    hri_cmcc_clear_CFG_reg(CMCC, CMCC_CFG_DCDIS | CMCC_CFG_ICDIS);
-    hri_nvmctrl_clear_CTRLA_CACHEDIS0_bit(NVMCTRL);
-    hri_nvmctrl_clear_CTRLA_CACHEDIS1_bit(NVMCTRL);
-
-    #endif
-
     // Update the next start.
     next_start_raw_ticks = port_get_raw_ticks(NULL) + 4;
 

ports/atmel-samd/supervisor/port.c

@@ -462,6 +462,8 @@ static uint32_t _get_count(uint64_t *overflow_count) {
     return count;
 }
 
+volatile bool _woken_up;
+
 static void _port_interrupt_after_ticks(uint32_t ticks) {
     uint32_t current_ticks = _get_count(NULL);
     if (ticks > 1 << 28) {
@@ -473,9 +475,16 @@ static void _port_interrupt_after_ticks(uint32_t ticks) {
         return;
     }
     #endif
-    RTC->MODE0.COMP[0].reg = current_ticks + (ticks << 4);
+    uint32_t target = current_ticks + (ticks << 4);
+    RTC->MODE0.COMP[0].reg = target;
+    #ifdef SAM_D5X_E5X
+    while ((RTC->MODE0.SYNCBUSY.reg & (RTC_MODE0_SYNCBUSY_COMP0)) != 0) {
+    }
+    #endif
     RTC->MODE0.INTFLAG.reg = RTC_MODE0_INTFLAG_CMP0;
     RTC->MODE0.INTENSET.reg = RTC_MODE0_INTENSET_CMP0;
+    current_ticks = _get_count(NULL);
+    _woken_up = current_ticks >= target;
 }
 
 void RTC_Handler(void) {
@@ -485,15 +494,18 @@ void RTC_Handler(void) {
         // Our RTC is 32 bits and we're clocking it at 16.384khz which is 16 (2 ** 4) subticks per
         // tick.
         overflowed_ticks += (1L << (32 - 4));
+    }
     #ifdef SAM_D5X_E5X
-    } else if (intflag & RTC_MODE0_INTFLAG_PER2) {
+    if (intflag & RTC_MODE0_INTFLAG_PER2) {
         RTC->MODE0.INTFLAG.reg = RTC_MODE0_INTFLAG_PER2;
         // Do things common to all ports when the tick occurs
         supervisor_tick();
+    }
     #endif
-    } else if (intflag & RTC_MODE0_INTFLAG_CMP0) {
+    if (intflag & RTC_MODE0_INTFLAG_CMP0) {
         // Clear the interrupt because we may have hit a sleep and _ticks_enabled
         RTC->MODE0.INTFLAG.reg = RTC_MODE0_INTFLAG_CMP0;
+        _woken_up = true;
         #ifdef SAMD21
         if (_ticks_enabled) {
             // Do things common to all ports when the tick occurs.
@@ -565,7 +577,7 @@ void port_idle_until_interrupt(void) {
     }
     #endif
     common_hal_mcu_disable_interrupts();
-    if (!tud_task_event_ready() && !hold_interrupt) {
+    if (!tud_task_event_ready() && !hold_interrupt && !_woken_up) {
         __DSB();
         __WFI();
     }

ports/nrf/boards/feather_nrf52840_express/mpconfigboard.h

@@ -30,7 +30,7 @@
 #define MICROPY_HW_BOARD_NAME       "Adafruit Feather nRF52840 Express"
 #define MICROPY_HW_MCU_NAME         "nRF52840"
 
-// #define MICROPY_HW_NEOPIXEL         (&pin_P0_16)
+#define MICROPY_HW_NEOPIXEL         (&pin_P0_16)
 
 #define MICROPY_HW_LED_STATUS       (&pin_P1_15)