Dotclock enhancements

ports/espressif/boards/adafruit_qualia_s3_rgb666/mpconfigboard.mk

@@ -11,6 +11,6 @@ CIRCUITPY_ESP_FLASH_FREQ = 80m
 
 CIRCUITPY_ESP_PSRAM_SIZE = 8MB
 CIRCUITPY_ESP_PSRAM_MODE = opi
-CIRCUITPY_ESP_PSRAM_FREQ = 80m
+CIRCUITPY_ESP_PSRAM_FREQ = 120m
 
 CIRCUITPY_DOTCLOCKFRAMEBUFFER = 1

ports/espressif/boards/adafruit_qualia_s3_rgb666/pins.c

@@ -1,6 +1,28 @@
 #include "py/objtuple.h"
 #include "shared-bindings/board/__init__.h"
 
+#define MP_DEFINE_BYTES_OBJ(obj_name, bin) mp_obj_str_t obj_name = {{&mp_type_bytes}, 0, sizeof(bin) - 1, (const byte *)bin}
+
+static const char i2c_bus_init_sequence[] = {
+    2, 3, 0x78, // set GPIO direction
+    2, 2, 0, // disable all output inversion
+    0, // trailing NUL for python bytes() representation
+};
+STATIC MP_DEFINE_BYTES_OBJ(i2c_init_byte_obj, i2c_bus_init_sequence);
+
+STATIC const mp_rom_map_elem_t tft_io_expander_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_i2c_address), MP_ROM_INT(0x3f)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_address), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_data_len), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_data), MP_ROM_INT(0xFD)},
+    { MP_ROM_QSTR(MP_QSTR_cs_bit), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_mosi_bit), MP_ROM_INT(7)},
+    { MP_ROM_QSTR(MP_QSTR_clk_bit), MP_ROM_INT(0)},
+    { MP_ROM_QSTR(MP_QSTR_reset_bit), MP_ROM_INT(2)},
+    { MP_ROM_QSTR(MP_QSTR_i2c_init_sequence), &i2c_init_byte_obj},
+};
+MP_DEFINE_CONST_DICT(tft_io_expander_dict, tft_io_expander_table);
+
 STATIC const mp_rom_obj_tuple_t tft_r_pins = {
     {&mp_type_tuple},
     5,
@@ -52,8 +74,8 @@ MP_DEFINE_CONST_DICT(tft_dict, tft_table);
 STATIC const mp_rom_map_elem_t board_module_globals_table[] = {
     CIRCUITPYTHON_BOARD_DICT_STANDARD_ITEMS
 
-    { MP_ROM_QSTR(MP_QSTR_TFT), MP_ROM_PTR(&tft_dict) },
-
+    { MP_ROM_QSTR(MP_QSTR_TFT_PINS), MP_ROM_PTR(&tft_dict) },
+    { MP_ROM_QSTR(MP_QSTR_TFT_IO_EXPANDER), MP_ROM_PTR(&tft_io_expander_dict) },
     { MP_ROM_QSTR(MP_QSTR_NEOPIXEL), MP_ROM_PTR(MICROPY_HW_NEOPIXEL) },
 
     { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_GPIO43) },

ports/espressif/boards/espressif_esp32s3_lcd_ev/board.c

@@ -33,6 +33,9 @@
 #include "shared-bindings/framebufferio/FramebufferDisplay.h"
 #include "shared-bindings/microcontroller/Pin.h"
 #include "shared-module/displayio/__init__.h"
+#include "boards/espressif_esp32s3_lcd_ev/board.h"
+
+#define MP_DEFINE_BYTES_OBJ(obj_name, bin) mp_obj_str_t obj_name = {{&mp_type_bytes}, 0, sizeof(bin) - 1, (const byte *)bin}
 
 static const uint8_t display_init_sequence[] = {
     0xf0, 5, 0x55, 0xaa, 0x52, 0x08, 0x00,
@@ -80,8 +83,17 @@ static const uint8_t display_init_sequence[] = {
     0x3a, 1, 0x66,
     0x3a, 1, 0x66,
     0x11, 0x80, 120,
-    0x29, 0x0
+    0x29, 0x0,
+    0, // trailing NUL for Python bytes() representation
+};
+MP_DEFINE_BYTES_OBJ(display_init_byte_obj, display_init_sequence);
+
+static const char i2c_bus_init_sequence[] = {
+    2, 3, 0xf1, // set GPIO direction
+    2, 2, 0, // disable all output inversion
+    0, // trailing NUL for Python bytes() representation
 };
+MP_DEFINE_BYTES_OBJ(i2c_init_byte_obj, i2c_bus_init_sequence);
 
 static const mcu_pin_obj_t *red_pins[] = {
     &pin_GPIO1, &pin_GPIO2, &pin_GPIO42, &pin_GPIO41, &pin_GPIO40
@@ -103,7 +115,7 @@ void board_init(void) {
         /* hsync */ &pin_GPIO46,
         /* dclk */ &pin_GPIO9,
         /* data */ red_pins, MP_ARRAY_SIZE(red_pins), green_pins, MP_ARRAY_SIZE(green_pins), blue_pins, MP_ARRAY_SIZE(blue_pins),
-        /* frequency */ 6500000,
+        /* frequency */ 12000000,
         /* width x height */ 480, 480,
         /* horizontal: pulse, back &  front porch, idle */ 13, 20, 40, false,
         /* vertical: pulse, back &  front porch, idle */ 15, 20, 40, false,
@@ -127,20 +139,6 @@ void board_init(void) {
     common_hal_busio_i2c_construct(&i2c, DEFAULT_I2C_BUS_SCL, DEFAULT_I2C_BUS_SDA, 400000, 255);
     const int i2c_device_address = 32;
 
-    common_hal_busio_i2c_try_lock(&i2c);
-
-    {
-        uint8_t buf[2] = {3, 0xf1}; // set GPIO direction
-        common_hal_busio_i2c_write(&i2c, i2c_device_address, buf, sizeof(buf));
-    }
-
-    {
-        uint8_t buf[2] = {2, 0}; // set all output pins low initially
-        common_hal_busio_i2c_write(&i2c, i2c_device_address, buf, sizeof(buf));
-    }
-
-    common_hal_busio_i2c_unlock(&i2c);
-
     dotclockframebuffer_ioexpander_spi_bus spibus = {
         .bus = &i2c,
         .i2c_device_address = i2c_device_address,
@@ -151,7 +149,9 @@ void board_init(void) {
             .clk_mask = 0x100 << 2,
     };
 
-    dotclockframebuffer_ioexpander_send_init_sequence(&spibus, display_init_sequence, sizeof(display_init_sequence));
+    static const mp_buffer_info_t bufinfo_display_init = { (void *)display_init_sequence, sizeof(display_init_sequence) - 1 };
+    static const mp_buffer_info_t bufinfo_i2c_bus_init = { (void *)i2c_bus_init_sequence, sizeof(i2c_bus_init_sequence) - 1 };
+    dotclockframebuffer_ioexpander_send_init_sequence(&spibus, &bufinfo_i2c_bus_init, &bufinfo_display_init);
 
     common_hal_busio_i2c_deinit(&i2c);
 }

ports/espressif/boards/espressif_esp32s3_lcd_ev/board.h

@@ -0,0 +1,31 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2023 Jeff Epler 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.
+ */
+
+#pragma once
+
+#include "py/objstr.h"
+
+extern mp_obj_str_t display_init_byte_obj, i2c_init_byte_obj;

ports/espressif/boards/espressif_esp32s3_lcd_ev/mpconfigboard.mk

@@ -11,7 +11,7 @@ CIRCUITPY_ESP_FLASH_SIZE = 16MB
 
 CIRCUITPY_ESP_PSRAM_SIZE = 8MB
 CIRCUITPY_ESP_PSRAM_MODE = opi
-CIRCUITPY_ESP_PSRAM_FREQ = 80m
+CIRCUITPY_ESP_PSRAM_FREQ = 120m
 
 CIRCUITPY_DOTCLOCKFRAMEBUFFER = 1
 UF2_BOOTLOADER = 0

ports/espressif/boards/espressif_esp32s3_lcd_ev/pins.c

@@ -1,7 +1,20 @@
 #include "py/objtuple.h"
+#include "boards/espressif_esp32s3_lcd_ev/board.h"
 #include "shared-bindings/board/__init__.h"
 #include "shared-module/displayio/__init__.h"
 
+STATIC const mp_rom_map_elem_t tft_io_expander_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_i2c_address), MP_ROM_INT(0x20)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_address), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_data_len), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_gpio_data), MP_ROM_INT(0xF1)},
+    { MP_ROM_QSTR(MP_QSTR_cs_bit), MP_ROM_INT(1)},
+    { MP_ROM_QSTR(MP_QSTR_mosi_bit), MP_ROM_INT(3)},
+    { MP_ROM_QSTR(MP_QSTR_clk_bit), MP_ROM_INT(2)},
+    { MP_ROM_QSTR(MP_QSTR_i2c_init_sequence), &i2c_init_byte_obj},
+};
+MP_DEFINE_CONST_DICT(tft_io_expander_dict, tft_io_expander_table);
+
 STATIC const mp_rom_obj_tuple_t tft_r_pins = {
     {&mp_type_tuple},
     5,
@@ -73,6 +86,8 @@ STATIC const mp_rom_map_elem_t board_module_globals_table[] = {
 
     { MP_ROM_QSTR(MP_QSTR_TFT_PINS), MP_ROM_PTR(&tft_pins_dict) },
     { MP_ROM_QSTR(MP_QSTR_TFT_TIMINGS), MP_ROM_PTR(&tft_timings_dict) },
+    { MP_ROM_QSTR(MP_QSTR_TFT_IO_EXPANDER), MP_ROM_PTR(&tft_io_expander_dict) },
+    { MP_ROM_QSTR(MP_QSTR_TFT_INIT_SEQUENCE), &display_init_byte_obj},
 
     { MP_ROM_QSTR(MP_QSTR_I2S_SCK), MP_ROM_PTR(&pin_GPIO16) },
     { MP_ROM_QSTR(MP_QSTR_I2S_MCLK), MP_ROM_PTR(&pin_GPIO5) },

ports/espressif/common-hal/busio/I2C.c

@@ -82,6 +82,7 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
     self->sda_pin = sda;
     self->scl_pin = scl;
     self->i2c_num = peripherals_i2c_get_free_num();
+    self->has_lock = 0;
 
     if (self->i2c_num == I2C_NUM_MAX) {
         mp_raise_ValueError(translate("All I2C peripherals are in use"));

ports/espressif/esp-idf-config/sdkconfig-esp32s3.defaults

@@ -57,6 +57,17 @@ CONFIG_I2S_SUPPRESS_DEPRECATE_WARN=y
 
 # end of Driver Configurations
 
+#
+# LCD and Touch Panel
+#
+#
+# LCD Peripheral Configuration
+#
+CONFIG_LCD_RGB_RESTART_IN_VSYNC=y
+# end of LCD Peripheral Configuration
+
+# end of LCD and Touch Panel
+
 #
 # ESP System Settings
 #

shared-bindings/dotclockframebuffer/__init__.c

@@ -39,15 +39,17 @@
 //|
 //| def ioexpander_send_init_sequence(
 //|     bus: busio.I2C,
+//|     init_sequence: ReadableBuffer,
+//|     *,
+//|     i2c_init_sequence: ReadableBuffer,
 //|     i2c_address: int,
-//|     reg_addr: int,
-//|     gpio_data_len: Length,
 //|     gpio_address: int,
+//|     gpio_data_len: Length,
 //|     gpio_data: int,
 //|     cs_bit: int,
 //|     mosi_bit: int,
 //|     clk_bit: int,
-//|     init_sequence: ReadableBuffer,
+//|     reset_bit: Optional[int],
 //| ):
 //|     """Send a displayio-style initialization sequence over an I2C I/O expander
 //|
@@ -60,30 +62,41 @@
 //|
 //|     Normally this function is used via a convenience library that is specific to the display & I/O expander in use.
 //|
+//|     If the board has an integrated I/O expander, ``**board.TFT_IO_EXPANDER`` expands to the proper arguments starting with ``gpio_address``.
+//|     Note that this may include the ``i2c_init_sequence`` argument which can change the direction & value of I/O expander pins.
+//|     If this is undesirable, take a copy of ``TFT_IO_EXPANDER`` and change or remove the ``i2c_init_sequence`` key.
+//|
+//|     If the board has an integrated display that requires an initialization sequence, ``board.TFT_INIT_SEQUENCE`` is the initialization string for the display.
+//|
 //|     :param busio.I2C bus: The I2C bus where the I/O expander resides
-//|     :param busio.i2c_address: int: The I2C bus address of the I/O expander
+//|     :param int busio.i2c_address: The I2C bus address of the I/O expander
+//|     :param ReadableBuffer init_sequence: The initialization sequence to send to the display
 //|     :param int gpio_address: The address portion of the I2C transaction (1 byte)
 //|     :param int gpio_data_len: The size of the data portion of the I2C transaction, 1 or 2 bytes
 //|     :param int gpio_data: The output value for all GPIO bits other than cs, mosi, and clk (needed because GPIO expanders may be unable to read back the current output value)
 //|     :param int cs_bit: The bit number (from 0 to 7, or from 0 to 15) of the chip select bit in the GPIO register
 //|     :param int mosi_value: The bit number (from 0 to 7, or from 0 to 15) of the data out bit in the GPIO register
 //|     :param int clk_value: The bit number (from 0 to 7, or from 0 to 15) of the clock out bit in the GPIO register
+//|     :param Optional[int] reset_value: The bit number (from 0 to 7, or from 0 to 15) of the display reset bit in the GPIO register
+//|     :param Optional[ReadableBuffer] i2c_init_sequence: An initialization sequence to send to the I2C expander
 //|     """
 //|
 
 STATIC mp_obj_t ioexpander_send_init_sequence(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
-    enum { ARG_bus, ARG_i2c_address, ARG_gpio_address, ARG_gpio_data_len, ARG_gpio_data, ARG_cs_bit, ARG_mosi_bit, ARG_clk_bit, ARG_init_sequence, NUM_ARGS };
+    enum { ARG_bus, ARG_init_sequence, ARG_i2c_address, ARG_gpio_address, ARG_gpio_data_len, ARG_gpio_data, ARG_cs_bit, ARG_mosi_bit, ARG_clk_bit, ARG_reset_bit, ARG_i2c_init_sequence, NUM_ARGS };
 
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_bus, MP_ARG_REQUIRED | MP_ARG_OBJ },
-        { MP_QSTR_i2c_address, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_gpio_address, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_gpio_data_len, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_gpio_data, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_cs_bit, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_mosi_bit, MP_ARG_REQUIRED | MP_ARG_INT },
-        { MP_QSTR_clk_bit, MP_ARG_REQUIRED | MP_ARG_INT },
         { MP_QSTR_init_sequence, MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_i2c_address, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_gpio_address, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_gpio_data_len, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_gpio_data, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_cs_bit, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_mosi_bit, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_clk_bit, MP_ARG_KW_ONLY | MP_ARG_REQUIRED | MP_ARG_INT },
+        { MP_QSTR_reset_bit, MP_ARG_KW_ONLY | MP_ARG_OBJ, { .u_obj = MP_ROM_NONE } },
+        { MP_QSTR_i2c_init_sequence, MP_ARG_KW_ONLY | MP_ARG_OBJ, { .u_obj = MP_ROM_NONE } },
     };
 
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
@@ -99,8 +112,8 @@ STATIC mp_obj_t ioexpander_send_init_sequence(size_t n_args, const mp_obj_t *pos
     mp_int_t mosi_bit = args[ARG_mosi_bit].u_int;
     mp_int_t clk_bit = args[ARG_clk_bit].u_int;
 
-    mp_buffer_info_t bufinfo;
-    mp_get_buffer_raise(args[ARG_init_sequence].u_obj, &bufinfo, MP_BUFFER_READ);
+    mp_buffer_info_t bufinfo_display_init_sequence;
+    mp_get_buffer_raise(args[ARG_init_sequence].u_obj, &bufinfo_display_init_sequence, MP_BUFFER_READ);
 
     mp_arg_validate_int_range(i2c_address, 0, 127, MP_QSTR_i2c_address);
     mp_arg_validate_int_range(gpio_data_len, 1, 2, MP_QSTR_gpio_dat_len);
@@ -110,6 +123,16 @@ STATIC mp_obj_t ioexpander_send_init_sequence(size_t n_args, const mp_obj_t *pos
     mp_arg_validate_int_range(mosi_bit, 0, max_bit, MP_QSTR_mosi_bit);
     mp_arg_validate_int_range(clk_bit, 0, max_bit, MP_QSTR_clk_bit);
     mp_arg_validate_int_range(gpio_data, 0, (1 << (max_bit * 8)) - 1, MP_QSTR_gpio_data);
+    mp_int_t reset_mask = 0;
+    if (args[ARG_reset_bit].u_obj != MP_ROM_NONE) {
+        mp_int_t reset_bit = mp_arg_validate_int_range(mp_arg_validate_type_int(args[ARG_reset_bit].u_obj, MP_QSTR_reset_bit), 0, max_bit, MP_QSTR_reset_bit);
+        reset_mask = 0x100 << reset_bit;
+    }
+
+    mp_buffer_info_t bufinfo_i2c_init_sequence = {};
+    if (args[ARG_i2c_init_sequence].u_obj != mp_const_none) {
+        mp_get_buffer_raise(args[ARG_i2c_init_sequence].u_obj, &bufinfo_i2c_init_sequence, MP_BUFFER_READ);
+    }
 
     dotclockframebuffer_ioexpander_spi_bus b = {
         .bus = bus_obj,
@@ -120,9 +143,10 @@ STATIC mp_obj_t ioexpander_send_init_sequence(size_t n_args, const mp_obj_t *pos
         .cs_mask = 0x100 << cs_bit,
             .mosi_mask = 0x100 << mosi_bit,
             .clk_mask = 0x100 << clk_bit,
+            .reset_mask = reset_mask,
     };
 
-    dotclockframebuffer_ioexpander_send_init_sequence(&b, bufinfo.buf, bufinfo.len);
+    dotclockframebuffer_ioexpander_send_init_sequence(&b, &bufinfo_i2c_init_sequence, &bufinfo_display_init_sequence);
     return mp_const_none;
 }
 

shared-bindings/dotclockframebuffer/__init__.h

@@ -51,6 +51,7 @@ typedef struct {
     uint32_t cs_mask;
     uint32_t mosi_mask;
     uint32_t clk_mask;
+    uint32_t reset_mask;
 } dotclockframebuffer_ioexpander_spi_bus;
 
-void dotclockframebuffer_ioexpander_send_init_sequence(dotclockframebuffer_ioexpander_spi_bus *bus, const uint8_t *init_sequence, uint16_t init_sequence_len);
+void dotclockframebuffer_ioexpander_send_init_sequence(dotclockframebuffer_ioexpander_spi_bus *bus, const mp_buffer_info_t *i2c_bus_init, const mp_buffer_info_t *display_init);

shared-module/displayio/__init__.c

@@ -43,6 +43,10 @@
 #include "supervisor/spi_flash_api.h"
 #include "py/mpconfig.h"
 
+#if CIRCUITPY_DOTCLOCKFRAMEBUFFER
+#include "shared-bindings/dotclockframebuffer/DotClockFramebuffer.h"
+#endif
+
 #if CIRCUITPY_SHARPDISPLAY
 #include "shared-bindings/sharpdisplay/SharpMemoryFramebuffer.h"
 #include "shared-module/sharpdisplay/SharpMemoryFramebuffer.h"
@@ -133,6 +137,10 @@ void common_hal_displayio_release_displays(void) {
             common_hal_displayio_fourwire_deinit(&display_buses[i].fourwire_bus);
         } else if (bus_type == &displayio_i2cdisplay_type) {
             common_hal_displayio_i2cdisplay_deinit(&display_buses[i].i2cdisplay_bus);
+        #if CIRCUITPY_DOTCLOCKFRAMEBUFFER
+        } else if (bus_type == &dotclockframebuffer_framebuffer_type) {
+            common_hal_dotclockframebuffer_framebuffer_deinit(&display_buses[i].dotclock);
+        #endif
         #if CIRCUITPY_PARALLELDISPLAY
         } else if (bus_type == &paralleldisplay_parallelbus_type) {
             common_hal_paralleldisplay_parallelbus_deinit(&display_buses[i].parallel_bus);

shared-module/dotclockframebuffer/__init__.c

@@ -43,15 +43,37 @@ static void ioexpander_bus_send(dotclockframebuffer_ioexpander_spi_bus *bus,
 //  * CPOL=CPHA=0
 //  * CS deasserted after each init sequence step, but not otherwise just like
 //    displayio fourwire bus without data_as_commands
-void dotclockframebuffer_ioexpander_send_init_sequence(dotclockframebuffer_ioexpander_spi_bus *bus, const uint8_t *init_sequence, uint16_t init_sequence_len) {
+void dotclockframebuffer_ioexpander_send_init_sequence(dotclockframebuffer_ioexpander_spi_bus *bus, const mp_buffer_info_t *i2c_bus_init, const mp_buffer_info_t *display_init) {
     while (!common_hal_busio_i2c_try_lock(bus->bus)) {
         RUN_BACKGROUND_TASKS;
     }
 
-    // ensure deasserted CS and idle CLK
-    pin_change(bus, /* set */ bus->cs_mask, /* clear */ bus->clk_mask);
+    // send i2c init sequence
+    {
+        size_t init_sequence_len = i2c_bus_init->len;
+        const uint8_t *init_sequence = i2c_bus_init->buf;
 
-    for (uint32_t i = 0; i < init_sequence_len; /* NO INCREMENT */) {
+        for (size_t i = 0; i < init_sequence_len; /* NO INCREMENT */) {
+            uint8_t data_size = init_sequence[i];
+            const uint8_t *data_ptr = &init_sequence[i + 1];
+            (void)common_hal_busio_i2c_write(bus->bus, bus->i2c_device_address, data_ptr, data_size);
+            i = i + data_size + 1;
+        }
+    }
+
+    // ensure deasserted CS and idle CLK (and set other pins according to addr_reg_shadow); enter reset mode if applicable
+    pin_change(bus, /* set */ bus->cs_mask, /* clear */ bus->clk_mask | bus->reset_mask);
+
+    if (bus->reset_mask) {
+        mp_hal_delay_ms(10); // reset pulse length
+        pin_change(bus, /* set */ bus->reset_mask, /* clear */ 0);
+        mp_hal_delay_ms(100); // display start-up time
+    }
+
+    size_t init_sequence_len = display_init->len;
+    const uint8_t *init_sequence = display_init->buf;
+
+    for (size_t i = 0; i < init_sequence_len; /* NO INCREMENT */) {
         const uint8_t *cmd = init_sequence + i;
         uint8_t data_size = *(cmd + 1);
         bool delay = (data_size & DELAY) != 0;