Merge remote-tracking branch 'adafruit/master' into HEAD

10 files changed, 600 insertions, 119 deletions

diff --git a/shared-module/displayio/Display.c b/shared-module/displayio/Display.c
new file mode 100644
index 000000000..f75f0392f
--- /dev/null
+++ b/shared-module/displayio/Display.c
@@ -0,0 +1,149 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/displayio/Display.h"
+
+#include "py/runtime.h"
+#include "shared-bindings/displayio/FourWire.h"
+#include "shared-bindings/displayio/ParallelBus.h"
+
+#include <stdint.h>
+
+#include "tick.h"
+
+#define DELAY 0x80
+
+void common_hal_displayio_display_construct(displayio_display_obj_t* self,
+        mp_obj_t bus, uint16_t width, uint16_t height, int16_t colstart, int16_t rowstart,
+        uint16_t color_depth, uint8_t set_column_command, uint8_t set_row_command,
+        uint8_t write_ram_command, uint8_t* init_sequence, uint16_t init_sequence_len) {
+    self->width = width;
+    self->height = height;
+    self->color_depth = color_depth;
+    self->set_column_command = set_column_command;
+    self->set_row_command = set_row_command;
+    self->write_ram_command = write_ram_command;
+    self->current_group = NULL;
+    self->colstart = colstart;
+    self->rowstart = rowstart;
+
+    if (MP_OBJ_IS_TYPE(bus, &displayio_parallelbus_type)) {
+        self->begin_transaction = common_hal_displayio_parallelbus_begin_transaction;
+        self->send = common_hal_displayio_parallelbus_send;
+        self->end_transaction = common_hal_displayio_parallelbus_end_transaction;
+    } else if (MP_OBJ_IS_TYPE(bus, &displayio_fourwire_type)) {
+        self->begin_transaction = common_hal_displayio_fourwire_begin_transaction;
+        self->send = common_hal_displayio_fourwire_send;
+        self->end_transaction = common_hal_displayio_fourwire_end_transaction;
+    } else {
+        mp_raise_ValueError(translate("Unsupported display bus type"));
+    }
+    self->bus = bus;
+
+    uint32_t i = 0;
+    self->begin_transaction(self->bus);
+    while (i < init_sequence_len) {
+        uint8_t *cmd = init_sequence + i;
+        uint8_t data_size = *(cmd + 1);
+        bool delay = (data_size & DELAY) != 0;
+        data_size &= ~DELAY;
+        uint8_t *data = cmd + 2;
+        self->send(self->bus, true, cmd, 1);
+        self->send(self->bus, false, data, data_size);
+        if (delay) {
+            data_size++;
+            uint16_t delay_length_ms = *(cmd + 1 + data_size);
+            if (delay_length_ms == 255) {
+                delay_length_ms = 500;
+            }
+            uint64_t start = ticks_ms;
+            while (ticks_ms - start < delay_length_ms) {}
+        } else {
+            uint64_t start = ticks_ms;
+            while (ticks_ms - start < 10) {}
+        }
+        i += 2 + data_size;
+    }
+    self->end_transaction(self->bus);
+}
+
+void common_hal_displayio_display_show(displayio_display_obj_t* self, displayio_group_t* root_group) {
+    self->current_group = root_group;
+    common_hal_displayio_display_refresh_soon(self);
+}
+
+void common_hal_displayio_display_refresh_soon(displayio_display_obj_t* self) {
+    self->refresh = true;
+}
+
+int32_t common_hal_displayio_display_wait_for_frame(displayio_display_obj_t* self) {
+    uint64_t last_refresh = self->last_refresh;
+    while (last_refresh == self->last_refresh) {
+        MICROPY_VM_HOOK_LOOP
+    }
+    return 0;
+}
+
+void displayio_display_start_region_update(displayio_display_obj_t* self, uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1) {
+    // TODO(tannewt): Handle displays with single byte bounds.
+    self->begin_transaction(self->bus);
+    uint16_t data[2];
+    self->send(self->bus, true, &self->set_column_command, 1);
+    data[0] = __builtin_bswap16(x0 + self->colstart);
+    data[1] = __builtin_bswap16(x1 - 1 + self->colstart);
+    self->send(self->bus, false, (uint8_t*) data, 4);
+    self->send(self->bus, true, &self->set_row_command, 1);
+    data[0] = __builtin_bswap16(y0 + 1 + self->rowstart);
+    data[1] = __builtin_bswap16(y1 + self->rowstart);
+    self->send(self->bus, false, (uint8_t*) data, 4);
+    self->send(self->bus, true, &self->write_ram_command, 1);
+}
+
+void displayio_display_finish_region_update(displayio_display_obj_t* self) {
+    self->end_transaction(self->bus);
+}
+
+bool displayio_display_frame_queued(displayio_display_obj_t* self) {
+    // Refresh at ~30 fps.
+    return (ticks_ms - self->last_refresh) > 32;
+}
+
+bool displayio_display_refresh_queued(displayio_display_obj_t* self) {
+    return self->refresh || (self->current_group != NULL && displayio_group_needs_refresh(self->current_group));
+}
+
+void displayio_display_finish_refresh(displayio_display_obj_t* self) {
+    if (self->current_group != NULL) {
+        displayio_group_finish_refresh(self->current_group);
+    }
+    self->refresh = false;
+    self->last_refresh = ticks_ms;
+}
+
+bool displayio_display_send_pixels(displayio_display_obj_t* self, uint32_t* pixels, uint32_t length) {
+    self->send(self->bus, false, (uint8_t*) pixels, length * 4);
+    return true;
+}
diff --git a/shared-module/displayio/Display.h b/shared-module/displayio/Display.h
new file mode 100644
index 000000000..1f1355d31
--- /dev/null
+++ b/shared-module/displayio/Display.h
@@ -0,0 +1,55 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_MODULE_DISPLAYIO_DISPLAY_H
+#define MICROPY_INCLUDED_SHARED_MODULE_DISPLAYIO_DISPLAY_H
+
+#include "shared-module/displayio/Group.h"
+
+typedef bool (*display_bus_begin_transaction)(mp_obj_t bus);
+typedef void (*display_bus_send)(mp_obj_t bus, bool command, uint8_t *data, uint32_t data_length);
+typedef void (*display_bus_end_transaction)(mp_obj_t bus);
+
+typedef struct {
+    mp_obj_base_t base;
+    mp_obj_t bus;
+    uint16_t width;
+    uint16_t height;
+    uint16_t color_depth;
+    uint8_t set_column_command;
+    uint8_t set_row_command;
+    uint8_t write_ram_command;
+    displayio_group_t *current_group;
+    bool refresh;
+    uint64_t last_refresh;
+    int16_t colstart;
+    int16_t rowstart;
+    display_bus_begin_transaction begin_transaction;
+    display_bus_send send;
+    display_bus_end_transaction end_transaction;
+} displayio_display_obj_t;
+
+#endif // MICROPY_INCLUDED_SHARED_MODULE_DISPLAYIO_DISPLAY_H
diff --git a/shared-module/displayio/FourWire.c b/shared-module/displayio/FourWire.c
new file mode 100644
index 000000000..9da5c0701
--- /dev/null
+++ b/shared-module/displayio/FourWire.c
@@ -0,0 +1,89 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/displayio/FourWire.h"
+
+#include <stdint.h>
+
+#include "shared-bindings/busio/SPI.h"
+#include "shared-bindings/digitalio/DigitalInOut.h"
+
+#include "tick.h"
+
+void common_hal_displayio_fourwire_construct(displayio_fourwire_obj_t* self,
+    busio_spi_obj_t* spi, const mcu_pin_obj_t* command,
+    const mcu_pin_obj_t* chip_select, const mcu_pin_obj_t* reset) {
+
+    self->bus = spi;
+    common_hal_busio_spi_never_reset(self->bus);
+
+    common_hal_digitalio_digitalinout_construct(&self->command, command);
+    common_hal_digitalio_digitalinout_switch_to_output(&self->command, true, DRIVE_MODE_PUSH_PULL);
+    common_hal_digitalio_digitalinout_construct(&self->chip_select, chip_select);
+    common_hal_digitalio_digitalinout_switch_to_output(&self->chip_select, true, DRIVE_MODE_PUSH_PULL);
+
+    if (reset != NULL) {
+        common_hal_digitalio_digitalinout_construct(&self->reset, reset);
+        common_hal_digitalio_digitalinout_switch_to_output(&self->reset, true, DRIVE_MODE_PUSH_PULL);
+        never_reset_pin_number(reset->number);
+    }
+
+    never_reset_pin_number(command->number);
+    never_reset_pin_number(chip_select->number);
+}
+
+void common_hal_displayio_fourwire_deinit(displayio_fourwire_obj_t* self) {
+    if (self->bus == &self->inline_bus) {
+        common_hal_busio_spi_deinit(self->bus);
+    }
+
+    reset_pin_number(self->command.pin->number);
+    reset_pin_number(self->chip_select.pin->number);
+    reset_pin_number(self->reset.pin->number);
+}
+
+bool common_hal_displayio_fourwire_begin_transaction(mp_obj_t obj) {
+    displayio_fourwire_obj_t* self = MP_OBJ_TO_PTR(obj);
+    if (!common_hal_busio_spi_try_lock(self->bus)) {
+        return false;
+    }
+    // TODO(tannewt): Stop hardcoding SPI frequency, polarity and phase.
+    common_hal_busio_spi_configure(self->bus, 12000000, 0, 0, 8);
+    common_hal_digitalio_digitalinout_set_value(&self->chip_select, false);
+    return true;
+}
+
+void common_hal_displayio_fourwire_send(mp_obj_t obj, bool command, uint8_t *data, uint32_t data_length) {
+    displayio_fourwire_obj_t* self = MP_OBJ_TO_PTR(obj);
+    common_hal_digitalio_digitalinout_set_value(&self->command, !command);
+    common_hal_busio_spi_write(self->bus, data, data_length);
+}
+
+void common_hal_displayio_fourwire_end_transaction(mp_obj_t obj) {
+    displayio_fourwire_obj_t* self = MP_OBJ_TO_PTR(obj);
+    common_hal_digitalio_digitalinout_set_value(&self->chip_select, true);
+    common_hal_busio_spi_unlock(self->bus);
+}
diff --git a/shared-module/displayio/FourWire.h b/shared-module/displayio/FourWire.h
new file mode 100644
index 000000000..234bcf794
--- /dev/null
+++ b/shared-module/displayio/FourWire.h
@@ -0,0 +1,43 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_DISPLAYIO_FOURWIRE_H
+#define MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_DISPLAYIO_FOURWIRE_H
+
+#include "common-hal/busio/SPI.h"
+#include "common-hal/digitalio/DigitalInOut.h"
+#include "shared-module/displayio/Group.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    busio_spi_obj_t* bus;
+    busio_spi_obj_t inline_bus;
+    digitalio_digitalinout_obj_t command;
+    digitalio_digitalinout_obj_t chip_select;
+    digitalio_digitalinout_obj_t reset;
+} displayio_fourwire_obj_t;
+
+#endif // MICROPY_INCLUDED_ATMEL_SAMD_COMMON_HAL_DISPLAYIO_FOURWIRE_H
diff --git a/shared-module/displayio/Group.c b/shared-module/displayio/Group.c
index b9923128a..255349d7c 100644
--- a/shared-module/displayio/Group.c
+++ b/shared-module/displayio/Group.c
@@ -67,11 +67,14 @@ void displayio_group_construct(displayio_group_t* self, mp_obj_t* child_array, u
     self->children = child_array;
     self->max_size = max_size;
     self->needs_refresh = false;
+    self->scale = 1;
 }
 
 bool displayio_group_get_pixel(displayio_group_t *self, int16_t x, int16_t y, uint16_t* pixel) {
     x -= self->x;
     y -= self->y;
+    x /= self->scale;
+    y /= self->scale;
     for (int32_t i = self->size - 1; i >= 0 ; i--) {
         mp_obj_t layer = self->children[i];
         if (MP_OBJ_IS_TYPE(layer, &displayio_sprite_type)) {
diff --git a/shared-module/displayio/Group.h b/shared-module/displayio/Group.h
index 272f3114c..60f573ff6 100644
--- a/shared-module/displayio/Group.h
+++ b/shared-module/displayio/Group.h
@@ -36,6 +36,7 @@ typedef struct {
     mp_obj_base_t base;
     int16_t x;
     int16_t y;
+    uint16_t scale;
     uint16_t size;
     uint16_t max_size;
     mp_obj_t* children;
diff --git a/shared-module/displayio/OnDiskBitmap.c b/shared-module/displayio/OnDiskBitmap.c
index 6e4a4c6f0..aa2ca3e10 100644
--- a/shared-module/displayio/OnDiskBitmap.c
+++ b/shared-module/displayio/OnDiskBitmap.c
@@ -91,3 +91,11 @@ uint32_t common_hal_displayio_ondiskbitmap_get_pixel(displayio_ondiskbitmap_t *s
     }
     return 0;
 }
+
+uint16_t common_hal_displayio_ondiskbitmap_get_height(displayio_ondiskbitmap_t *self) {
+    return self->height;
+}
+
+uint16_t common_hal_displayio_ondiskbitmap_get_width(displayio_ondiskbitmap_t *self) {
+    return self->width;
+}
diff --git a/shared-module/displayio/__init__.c b/shared-module/displayio/__init__.c
index f1a00db9f..59a5cf398 100644
--- a/shared-module/displayio/__init__.c
+++ b/shared-module/displayio/__init__.c
@@ -1,91 +1,188 @@
-#include "shared-bindings/displayio/FourWire.h"
 
-extern displayio_fourwire_obj_t board_display_obj;
+#include <string.h>
+#include "shared-module/displayio/__init__.h"
 
-void start_region_update(displayio_fourwire_obj_t* display, uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1) {
-    // TODO delegate between different display types
-    displayio_fourwire_start_region_update(display, x0, y0, x1, y1);
-}
+#include "shared-bindings/displayio/Bitmap.h"
+#include "shared-bindings/displayio/Display.h"
+#include "shared-bindings/displayio/Group.h"
+#include "shared-bindings/displayio/Palette.h"
+#include "shared-bindings/displayio/Sprite.h"
+#include "supervisor/usb.h"
 
-void finish_region_update(displayio_fourwire_obj_t* display) {
-    // TODO delegate between different display types
-    displayio_fourwire_finish_region_update(display);
-}
+primary_display_t displays[CIRCUITPY_DISPLAY_LIMIT];
 
-void finish_refresh(displayio_fourwire_obj_t* display) {
-    // TODO delegate between different display types
-    displayio_fourwire_finish_refresh(display);
-}
+void displayio_refresh_displays(void) {
+    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
+        if (displays[i].display.base.type == NULL || displays[i].display.base.type == &mp_type_NoneType) {
+            continue;
+        }
+        displayio_display_obj_t* display = &displays[i].display;
 
-bool frame_queued(displayio_fourwire_obj_t* display) {
-    // TODO delegate between different display types
-    return displayio_fourwire_frame_queued(display);
-}
+        if (!displayio_display_frame_queued(display)) {
+            return;
+        }
+        if (displayio_display_refresh_queued(display)) {
+            // We compute the pixels
+            uint16_t x0 = 0;
+            uint16_t y0 = 0;
+            uint16_t x1 = display->width;
+            uint16_t y1 = display->height;
+            size_t index = 0;
+            //size_t row_size = (x1 - x0);
+            uint16_t buffer_size = 256;
+            uint32_t buffer[buffer_size / 2];
+            displayio_display_start_region_update(display, x0, y0, x1, y1);
+            for (uint16_t y = y0; y < y1; ++y) {
+                for (uint16_t x = x0; x < x1; ++x) {
+                    uint16_t* pixel = &(((uint16_t*)buffer)[index]);
+                    *pixel = 0;
 
-bool refresh_queued(displayio_fourwire_obj_t* display) {
-    // TODO delegate between different display types
-    return displayio_fourwire_refresh_queued(display);
-}
+                    if (display->current_group != NULL) {
+                        displayio_group_get_pixel(display->current_group, x, y, pixel);
+                    }
 
-bool send_pixels(displayio_fourwire_obj_t* display, uint32_t* pixels, uint32_t length) {
-    // TODO delegate between different display types
-    return displayio_fourwire_send_pixels(display, pixels, length);
+                    index += 1;
+                    // The buffer is full, send it.
+                    if (index >= buffer_size) {
+                        if (!displayio_display_send_pixels(display, buffer, buffer_size / 2)) {
+                            displayio_display_finish_region_update(display);
+                            return;
+                        }
+                        // TODO(tannewt): Make refresh displays faster so we don't starve other
+                        // background tasks.
+                        usb_background();
+                        index = 0;
+                    }
+                }
+            }
+            // Send the remaining data.
+            if (index && !displayio_display_send_pixels(display, buffer, index * 2)) {
+                displayio_display_finish_region_update(display);
+                return;
+            }
+            displayio_display_finish_region_update(display);
+        }
+        displayio_display_finish_refresh(display);
+    }
 }
 
-void displayio_refresh_display(void) {
-    displayio_fourwire_obj_t* display = &board_display_obj;
+uint32_t blinka_bitmap_data[32] = {
+    0x00000011, 0x11000000,
+    0x00000111, 0x53100000,
+    0x00000111, 0x56110000,
+    0x00000111, 0x11140000,
+    0x00000111, 0x20002000,
+    0x00000011, 0x13000000,
+    0x00000001, 0x11200000,
+    0x00000000, 0x11330000,
+    0x00000000, 0x01122000,
+    0x00001111, 0x44133000,
+    0x00032323, 0x24112200,
+    0x00111114, 0x44113300,
+    0x00323232, 0x34112200,
+    0x11111144, 0x44443300,
+    0x11111111, 0x11144401,
+    0x23232323, 0x21111110
+};
 
-    if (!frame_queued(display)) {
-        return;
-    }
-    if (refresh_queued(display)) {
-        PORT->Group[1].DIRSET.reg = 1 << 22;
-
-        // We compute the pixels
-        uint16_t x0 = 0;
-        uint16_t y0 = 0;
-        uint16_t x1 = display->width;
-        uint16_t y1 = display->height;
-        size_t index = 0;
-        //size_t row_size = (x1 - x0);
-        uint16_t buffer_size = 256;
-        uint32_t buffer[buffer_size / 2];
-        start_region_update(display, x0, y0, x1, y1);
-        for (uint16_t y = y0; y < y1; ++y) {
-            for (uint16_t x = x0; x < x1; ++x) {
-                uint16_t* pixel = &(((uint16_t*)buffer)[index]);
-                *pixel = 0;
-
-                PORT->Group[1].OUTTGL.reg = 1 << 22;
-
-                //if (index == 0) {
-                    if (display->current_group != NULL) {
-                        displayio_group_get_pixel(display->current_group, x, y, pixel);
-                    }
-                // } else {
-                //     *pixel = (((uint16_t*)buffer)[0]);
-                // }
+displayio_bitmap_t blinka_bitmap = {
+    .base = {.type = &displayio_bitmap_type },
+    .width = 16,
+    .height = 16,
+    .data = blinka_bitmap_data,
+    .stride = 2,
+    .bits_per_value = 4,
+    .x_shift = 3,
+    .x_mask = 0x7,
+    .bitmask = 0xf
+};
 
+uint32_t blinka_transparency[1] = {0x80000000};
 
-                PORT->Group[1].OUTTGL.reg = 1 << 22;
+// TODO(tannewt): Fix these colors
+uint32_t blinka_colors[8] = {0x91780000, 0x879FFC98, 0xffff0000, 0x0000f501,
+                             0x00000000, 0x00000000, 0x00000000, 0x00000000};
 
-                index += 1;
-                // The buffer is full, send it.
-                if (index >= buffer_size) {
-                    if (!send_pixels(display, buffer, buffer_size / 2)) {
-                        finish_region_update(display);
-                        return;
-                    }
-                    index = 0;
+displayio_palette_t blinka_palette = {
+    .base = {.type = &displayio_palette_type },
+    .opaque = blinka_transparency,
+    .colors = blinka_colors,
+    .color_count = 16,
+    .needs_refresh = false
+};
+
+displayio_sprite_t blinka_sprite = {
+    .base = {.type = &displayio_sprite_type },
+    .bitmap = &blinka_bitmap,
+    .pixel_shader = &blinka_palette,
+    .x = 0,
+    .y = 0,
+    .width = 16,
+    .height = 16,
+    .needs_refresh = false
+};
+
+mp_obj_t splash_children[1] = {
+    &blinka_sprite,
+};
+
+displayio_group_t splash = {
+    .base = {.type = &displayio_group_type },
+    .x = 0,
+    .y = 0,
+    .scale = 2,
+    .size = 1,
+    .max_size = 1,
+    .children = splash_children,
+    .needs_refresh = true
+};
+
+void reset_displays(void) {
+    // The SPI buses used by FourWires may be allocated on the heap so we need to move them inline.
+    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
+        if (displays[i].fourwire_bus.base.type != &displayio_fourwire_type) {
+            continue;
+        }
+        displayio_fourwire_obj_t* fourwire = &displays[i].fourwire_bus;
+        if (((uint32_t) fourwire->bus) < ((uint32_t) &displays) ||
+            ((uint32_t) fourwire->bus) > ((uint32_t) &displays + CIRCUITPY_DISPLAY_LIMIT)) {
+            busio_spi_obj_t* original_spi = fourwire->bus;
+            if (original_spi == board_spi()) {
+                continue;
+            }
+            memcpy(&fourwire->inline_bus, original_spi, sizeof(busio_spi_obj_t));
+            fourwire->bus = &fourwire->inline_bus;
+            // Check for other displays that use the same spi bus and swap them too.
+            for (uint8_t j = i + 1; j < CIRCUITPY_DISPLAY_LIMIT; j++) {
+                if (displays[i].fourwire_bus.bus == original_spi) {
+                    displays[i].fourwire_bus.bus = &fourwire->inline_bus;
                 }
             }
         }
-        // Send the remaining data.
-        if (index && !send_pixels(display, buffer, index * 2)) {
-            finish_region_update(display);
-            return;
+    }
+
+    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
+        if (displays[i].display.base.type == NULL) {
+            continue;
         }
-        finish_region_update(display);
+        displayio_display_obj_t* display = &displays[i].display;
+        common_hal_displayio_display_show(display, &splash);
+    }
+}
+
+void common_hal_displayio_release_displays(void) {
+    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
+        mp_const_obj_t bus_type = displays[i].fourwire_bus.base.type;
+        if (bus_type == NULL) {
+            continue;
+        } else if (bus_type == &displayio_fourwire_type) {
+            common_hal_displayio_fourwire_deinit(&displays[i].fourwire_bus);
+        } else if (bus_type == &displayio_parallelbus_type) {
+            common_hal_displayio_parallelbus_deinit(&displays[i].parallel_bus);
+        }
+        displays[i].fourwire_bus.base.type = &mp_type_NoneType;
+    }
+    for (uint8_t i = 0; i < CIRCUITPY_DISPLAY_LIMIT; i++) {
+        displays[i].display.base.type = &mp_type_NoneType;
     }
-    finish_refresh(display);
 }
diff --git a/shared-module/displayio/__init__.h b/shared-module/displayio/__init__.h
index 556af430d..fdabd4ec4 100644
--- a/shared-module/displayio/__init__.h
+++ b/shared-module/displayio/__init__.h
@@ -27,6 +27,21 @@
 #ifndef MICROPY_INCLUDED_SHARED_BINDINGS_DISPLAYIO___INIT___H
 #define MICROPY_INCLUDED_SHARED_BINDINGS_DISPLAYIO___INIT___H
 
-void displayio_refresh_display(void);
+#include "shared-bindings/displayio/Display.h"
+#include "shared-bindings/displayio/FourWire.h"
+#include "shared-bindings/displayio/ParallelBus.h"
+
+typedef struct {
+    union {
+        displayio_fourwire_obj_t fourwire_bus;
+        displayio_parallelbus_obj_t parallel_bus;
+    };
+    displayio_display_obj_t display;
+} primary_display_t;
+
+extern primary_display_t displays[CIRCUITPY_DISPLAY_LIMIT];
+
+void displayio_refresh_displays(void);
+void reset_displays(void);
 
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_DISPLAYIO___INIT___H
diff --git a/shared-module/struct/__init__.c b/shared-module/struct/__init__.c
index 78c04f07b..245dbbda9 100644
--- a/shared-module/struct/__init__.c
+++ b/shared-module/struct/__init__.c
@@ -71,45 +71,6 @@ mp_uint_t get_fmt_num(const char **p) {
     return val;
 }
 
-void shared_modules_struct_pack_into(mp_obj_t fmt_in, byte *p, byte* end_p, size_t n_args, const mp_obj_t *args) {
-    const char *fmt = mp_obj_str_get_str(fmt_in);
-    char fmt_type = get_fmt_type(&fmt);
-
-    size_t i;
-    for (i = 0; i < n_args;) {
-        mp_uint_t sz = 1;
-        if (*fmt == '\0') {
-            // more arguments given than used by format string; CPython raises struct.error here
-            mp_raise_RuntimeError(translate("too many arguments provided with the given format"));
-        }
-        struct_validate_format(*fmt);
-
-        if (unichar_isdigit(*fmt)) {
-            sz = get_fmt_num(&fmt);
-        }
-        if (p + sz > end_p) {
-            mp_raise_RuntimeError(translate("buffer too small"));
-        }
-
-        if (*fmt == 's') {
-            mp_buffer_info_t bufinfo;
-            mp_get_buffer_raise(args[i++], &bufinfo, MP_BUFFER_READ);
-            mp_uint_t to_copy = sz;
-            if (bufinfo.len < to_copy) {
-                to_copy = bufinfo.len;
-            }
-            memcpy(p, bufinfo.buf, to_copy);
-            memset(p + to_copy, 0, sz - to_copy);
-            p += sz;
-        } else {
-            while (sz--) {
-                mp_binary_set_val(fmt_type, *fmt, args[i++], &p);
-            }
-        }
-        fmt++;
-    }
-}
-
 mp_uint_t calcsize_items(const char *fmt) {
     mp_uint_t cnt = 0;
     while (*fmt) {
@@ -120,7 +81,10 @@ mp_uint_t calcsize_items(const char *fmt) {
                 num = 1;
             }
         }
-        cnt += num;
+        // Pad bytes are skipped and don't get included in the item count.
+        if (*fmt != 'x') {
+            cnt += num;
+        }
         fmt++;
     }
     return cnt;
@@ -155,14 +119,71 @@ mp_uint_t shared_modules_struct_calcsize(mp_obj_t fmt_in) {
     return size;
 }
 
+void shared_modules_struct_pack_into(mp_obj_t fmt_in, byte *p, byte* end_p, size_t n_args, const mp_obj_t *args) {
+    const char *fmt = mp_obj_str_get_str(fmt_in);
+    char fmt_type = get_fmt_type(&fmt);
+    const mp_uint_t total_sz = shared_modules_struct_calcsize(fmt_in);
+
+    if (p + total_sz > end_p) {
+        mp_raise_RuntimeError(translate("buffer too small"));
+    }
+
+    size_t i;
+    for (i = 0; i < n_args;) {
+        mp_uint_t sz = 1;
+        if (*fmt == '\0') {
+            // more arguments given than used by format string; CPython raises struct.error here
+            mp_raise_RuntimeError(translate("too many arguments provided with the given format"));
+        }
+        struct_validate_format(*fmt);
+
+        if (unichar_isdigit(*fmt)) {
+            sz = get_fmt_num(&fmt);
+        }
+
+        if (*fmt == 's') {
+            mp_buffer_info_t bufinfo;
+            mp_get_buffer_raise(args[i++], &bufinfo, MP_BUFFER_READ);
+            mp_uint_t to_copy = sz;
+            if (bufinfo.len < to_copy) {
+                to_copy = bufinfo.len;
+            }
+            memcpy(p, bufinfo.buf, to_copy);
+            memset(p + to_copy, 0, sz - to_copy);
+            p += sz;
+        } else {
+            while (sz--) {
+                mp_binary_set_val(fmt_type, *fmt, args[i], &p);
+                // Pad bytes don't have a corresponding argument.
+                if (*fmt != 'x') {
+                    i++;
+                }
+            }
+        }
+        fmt++;
+    }
+}
 
-mp_obj_tuple_t * shared_modules_struct_unpack_from(mp_obj_t fmt_in, byte *p, byte *end_p) {
+mp_obj_tuple_t * shared_modules_struct_unpack_from(mp_obj_t fmt_in, byte *p, byte *end_p, bool exact_size) {
 
   const char *fmt = mp_obj_str_get_str(fmt_in);
   char fmt_type = get_fmt_type(&fmt);
-  mp_uint_t num_items = calcsize_items(fmt);
+  const mp_uint_t num_items = calcsize_items(fmt);
+  const mp_uint_t total_sz = shared_modules_struct_calcsize(fmt_in);
   mp_obj_tuple_t *res = MP_OBJ_TO_PTR(mp_obj_new_tuple(num_items, NULL));
 
+  // If exact_size, make sure the buffer is exactly the right size.
+  // Otherwise just make sure it's big enough.
+  if (exact_size) {
+      if (p + total_sz != end_p) {
+          mp_raise_RuntimeError(translate("buffer size must match format"));
+      }
+  } else {
+      if (p + total_sz > end_p) {
+          mp_raise_RuntimeError(translate("buffer too small"));
+      }
+  }
+
   for (uint i = 0; i < num_items;) {
       mp_uint_t sz = 1;
 
@@ -171,9 +192,6 @@ mp_obj_tuple_t * shared_modules_struct_unpack_from(mp_obj_t fmt_in, byte *p, byt
       if (unichar_isdigit(*fmt)) {
           sz = get_fmt_num(&fmt);
       }
-      if (p + sz > end_p) {
-          mp_raise_RuntimeError(translate("buffer too small"));
-      }
       mp_obj_t item;
       if (*fmt == 's') {
           item = mp_obj_new_bytes(p, sz);
@@ -182,7 +200,10 @@ mp_obj_tuple_t * shared_modules_struct_unpack_from(mp_obj_t fmt_in, byte *p, byt
       } else {
           while (sz--) {
               item = mp_binary_get_val(fmt_type, *fmt, &p);
-              res->items[i++] = item;
+              // Pad bytes are not stored.
+              if (*fmt != 'x') {
+                  res->items[i++] = item;
+              }
           }
       }
       fmt++;