3 files changed, 32 insertions, 9 deletions

diff --git a/shared-module/displayio/Display.c b/shared-module/displayio/Display.c
index 0e76a868f..eccb2d0ef 100644
--- a/shared-module/displayio/Display.c
+++ b/shared-module/displayio/Display.c
@@ -44,7 +44,7 @@ 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 rotation,
         uint16_t color_depth, uint8_t set_column_command, uint8_t set_row_command,
         uint8_t write_ram_command, uint8_t set_vertical_scroll, uint8_t* init_sequence, uint16_t init_sequence_len,
-        const mcu_pin_obj_t* backlight_pin) {
+        const mcu_pin_obj_t* backlight_pin, bool single_byte_bounds) {
     self->color_depth = color_depth;
     self->set_column_command = set_column_command;
     self->set_row_command = set_row_command;
@@ -54,6 +54,7 @@ void common_hal_displayio_display_construct(displayio_display_obj_t* self,
     self->colstart = colstart;
     self->rowstart = rowstart;
     self->auto_brightness = false;
+    self->single_byte_bounds = single_byte_bounds;
 
     if (MP_OBJ_IS_TYPE(bus, &displayio_parallelbus_type)) {
         self->begin_transaction = common_hal_displayio_parallelbus_begin_transaction;
@@ -211,16 +212,31 @@ void displayio_display_end_transaction(displayio_display_obj_t* self) {
 }
 
 void displayio_display_set_region_to_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.
-    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);
+    if (self->single_byte_bounds) {
+        uint8_t data[2];
+        data[0] = x0 + self->colstart;
+        data[1] = x1 - 1 + self->colstart;
+        self->send(self->bus, false, (uint8_t*) data, 2);
+    } else {
+        uint16_t data[2];
+        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  + self->rowstart);
-    data[1] = __builtin_bswap16(y1 - 1 + self->rowstart);
-    self->send(self->bus, false, (uint8_t*) data, 4);
+    if (self->single_byte_bounds) {
+        uint8_t data[2];
+        data[0] = y0 + self->rowstart;
+        data[1] = y1 - 1 + self->rowstart;
+        self->send(self->bus, false, (uint8_t*) data, 2);
+    } else {
+        uint16_t data[2];
+        data[0] = __builtin_bswap16(y0  + self->rowstart);
+        data[1] = __builtin_bswap16(y1 - 1 + self->rowstart);
+        self->send(self->bus, false, (uint8_t*) data, 4);
+    }
     self->send(self->bus, true, &self->write_ram_command, 1);
 }
 
diff --git a/shared-module/displayio/Display.h b/shared-module/displayio/Display.h
index 04da68b63..4ccae37bf 100644
--- a/shared-module/displayio/Display.h
+++ b/shared-module/displayio/Display.h
@@ -49,6 +49,7 @@ typedef struct {
     uint64_t last_refresh;
     int16_t colstart;
     int16_t rowstart;
+    bool single_byte_bounds;
     display_bus_begin_transaction begin_transaction;
     display_bus_send send;
     display_bus_end_transaction end_transaction;
diff --git a/shared-module/displayio/FourWire.c b/shared-module/displayio/FourWire.c
index 9da5c0701..043f68e26 100644
--- a/shared-module/displayio/FourWire.c
+++ b/shared-module/displayio/FourWire.c
@@ -30,6 +30,7 @@
 
 #include "shared-bindings/busio/SPI.h"
 #include "shared-bindings/digitalio/DigitalInOut.h"
+#include "shared-bindings/time/__init__.h"
 
 #include "tick.h"
 
@@ -78,6 +79,11 @@ bool common_hal_displayio_fourwire_begin_transaction(mp_obj_t obj) {
 
 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);
+    if (command) {
+        common_hal_digitalio_digitalinout_set_value(&self->chip_select, true);
+        common_hal_time_delay_ms(1);
+        common_hal_digitalio_digitalinout_set_value(&self->chip_select, false);
+    }
     common_hal_digitalio_digitalinout_set_value(&self->command, !command);
     common_hal_busio_spi_write(self->bus, data, data_length);
 }