Merge branch 'develop' -- breaking changes 2022-05-28.

28 files changed, 2416 insertions, 138 deletions

diff --git a/drivers/gpio/sn74x154.c b/drivers/gpio/sn74x154.c
new file mode 100644
index 0000000000..5f21f12b55
--- /dev/null
+++ b/drivers/gpio/sn74x154.c
@@ -0,0 +1,58 @@
+/* Copyright 2022
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "sn74x154.h"
+#include "gpio.h"
+
+#define ADDRESS_PIN_COUNT 4
+
+#ifndef SN74X154_ADDRESS_PINS
+#    error sn74x154: no address pins defined!
+#endif
+
+static const pin_t address_pins[ADDRESS_PIN_COUNT] = SN74X154_ADDRESS_PINS;
+
+void sn74x154_init(void) {
+    for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+        setPinOutput(address_pins[i]);
+        writePinLow(address_pins[i]);
+    }
+
+#if defined(SN74X154_E0_PIN)
+    setPinOutput(SN74X154_E0_PIN);
+    writePinHigh(SN74X154_E0_PIN);
+#endif
+
+#if defined(SN74X154_E1_PIN)
+    setPinOutput(SN74X154_E1_PIN);
+    writePinHigh(SN74X154_E1_PIN);
+#endif
+}
+
+void sn74x154_set_enabled(bool enabled) {
+#if defined(SN74X154_E0_PIN)
+    writePin(SN74X154_E0_PIN, !enabled);
+#endif
+#if defined(SN74X154_E1_PIN)
+    writePin(SN74X154_E1_PIN, !enabled);
+#endif
+}
+
+void sn74x154_set_addr(uint8_t address) {
+    for (int i = 0; i < ADDRESS_PIN_COUNT; i++) {
+        writePin(address_pins[i], address & (1 << i));
+    }
+}
diff --git a/drivers/gpio/sn74x154.h b/drivers/gpio/sn74x154.h
new file mode 100644
index 0000000000..ce6a9ddb0e
--- /dev/null
+++ b/drivers/gpio/sn74x154.h
@@ -0,0 +1,48 @@
+/* Copyright 2022
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * Driver for 74x154 4-to-16 decoder/demultiplexer with inverting outputs
+ * https://assets.nexperia.com/documents/data-sheet/74HC_HCT154.pdf
+ */
+
+/**
+ * Initialize the address and output enable pins.
+ */
+void sn74x154_init(void);
+
+/**
+ * Set the enabled state.
+ *
+ * When enabled is true, pulls the E0 and E1 pins low.
+ *
+ * \param enabled The enable state to set.
+ */
+void sn74x154_set_enabled(bool enabled);
+
+/**
+ * Set the output pin address.
+ *
+ * The selected output pin will be pulled low, while the remaining output pins will be high.
+ *
+ * \param address The address to set, from 0 to 15.
+ */
+void sn74x154_set_addr(uint8_t address);
diff --git a/drivers/haptic/solenoid.c b/drivers/haptic/solenoid.c
index 14d868bffe..637a77da3d 100644
--- a/drivers/haptic/solenoid.c
+++ b/drivers/haptic/solenoid.c
@@ -20,11 +20,22 @@
 #include "haptic.h"
 #include "gpio.h"
 #include "usb_device_state.h"
-
-bool     solenoid_on      = false;
-bool     solenoid_buzzing = false;
-uint16_t solenoid_start   = 0;
-uint8_t  solenoid_dwell   = SOLENOID_DEFAULT_DWELL;
+#include <stdlib.h>
+
+uint8_t      solenoid_dwell  = SOLENOID_DEFAULT_DWELL;
+static pin_t solenoid_pads[] = SOLENOID_PINS;
+#define NUMBER_OF_SOLENOIDS (sizeof(solenoid_pads) / sizeof(pin_t))
+bool     solenoid_on[NUMBER_OF_SOLENOIDS]      = {false};
+bool     solenoid_buzzing[NUMBER_OF_SOLENOIDS] = {false};
+uint16_t solenoid_start[NUMBER_OF_SOLENOIDS]   = {0};
+#ifdef SOLENOID_PIN_ACTIVE_LOW
+#    define low true
+#    define high false
+#else
+#    define low false
+#    define high true
+#endif
+static bool solenoid_active_state[NUMBER_OF_SOLENOIDS];
 
 extern haptic_config_t haptic_config;
 
@@ -36,7 +47,7 @@ void solenoid_buzz_off(void) {
     haptic_set_buzz(0);
 }
 
-void solenoid_set_buzz(int buzz) {
+void solenoid_set_buzz(uint8_t buzz) {
     haptic_set_buzz(buzz);
 }
 
@@ -44,59 +55,121 @@ void solenoid_set_dwell(uint8_t dwell) {
     solenoid_dwell = dwell;
 }
 
-void solenoid_stop(void) {
-    SOLENOID_PIN_WRITE_INACTIVE();
-    solenoid_on      = false;
-    solenoid_buzzing = false;
+/**
+ * @brief Stops a specific solenoid
+ *
+ * @param index select which solenoid to check/stop
+ */
+void solenoid_stop(uint8_t index) {
+    writePin(solenoid_pads[index], !solenoid_active_state[index]);
+    solenoid_on[index]      = false;
+    solenoid_buzzing[index] = false;
 }
 
-void solenoid_fire(void) {
-    if (!haptic_config.buzz && solenoid_on) return;
-    if (haptic_config.buzz && solenoid_buzzing) return;
+/**
+ * @brief Fires off a specific solenoid
+ *
+ * @param index Selects which solenoid to fire
+ */
+void solenoid_fire(uint8_t index) {
+    if (!haptic_config.buzz && solenoid_on[index]) return;
+    if (haptic_config.buzz && solenoid_buzzing[index]) return;
+
+    solenoid_on[index]      = true;
+    solenoid_buzzing[index] = true;
+    solenoid_start[index]   = timer_read();
+    writePin(solenoid_pads[index], solenoid_active_state[index]);
+}
 
-    solenoid_on      = true;
-    solenoid_buzzing = true;
-    solenoid_start   = timer_read();
-    SOLENOID_PIN_WRITE_ACTIVE();
+/**
+ * @brief Handles selecting a non-active solenoid, and firing it.
+ *
+ */
+void solenoid_fire_handler(void) {
+#ifndef SOLENOID_RANDOM_FIRE
+    if (NUMBER_OF_SOLENOIDS > 1) {
+        uint8_t i = rand() % NUMBER_OF_SOLENOIDS;
+        if (!solenoid_on[i]) {
+            solenoid_fire(i);
+        }
+    } else {
+        solenoid_fire(0);
+    }
+#else
+    for (uint8_t i = 0; i < NUMBER_OF_SOLENOIDS; i++) {
+        if (!solenoid_on[i]) {
+            solenoid_fire(i);
+            break;
+        }
+    }
+#endif
 }
 
+/**
+ * @brief Checks active solenoid to stop them, and to handle buzz mode
+ *
+ */
 void solenoid_check(void) {
-    uint16_t elapsed = 0;
+    uint16_t elapsed[NUMBER_OF_SOLENOIDS] = {0};
 
-    if (!solenoid_on) return;
+    for (uint8_t i = 0; i < NUMBER_OF_SOLENOIDS; i++) {
+        if (!solenoid_on[i]) continue;
 
-    elapsed = timer_elapsed(solenoid_start);
+        elapsed[i] = timer_elapsed(solenoid_start[i]);
 
-    // Check if it's time to finish this solenoid click cycle
-    if (elapsed > solenoid_dwell) {
-        solenoid_stop();
-        return;
-    }
+        // Check if it's time to finish this solenoid click cycle
+        if (elapsed[i] > solenoid_dwell) {
+            solenoid_stop(i);
+            continue;
+        }
 
-    // Check whether to buzz the solenoid on and off
-    if (haptic_config.buzz) {
-        if ((elapsed % (SOLENOID_BUZZ_ACTUATED + SOLENOID_BUZZ_NONACTUATED)) < SOLENOID_BUZZ_ACTUATED) {
-            if (!solenoid_buzzing) {
-                solenoid_buzzing = true;
-                SOLENOID_PIN_WRITE_ACTIVE();
-            }
-        } else {
-            if (solenoid_buzzing) {
-                solenoid_buzzing = false;
-                SOLENOID_PIN_WRITE_INACTIVE();
+        // Check whether to buzz the solenoid on and off
+        if (haptic_config.buzz) {
+            if ((elapsed[i] % (SOLENOID_BUZZ_ACTUATED + SOLENOID_BUZZ_NONACTUATED)) < SOLENOID_BUZZ_ACTUATED) {
+                if (!solenoid_buzzing[i]) {
+                    solenoid_buzzing[i] = true;
+                    writePin(solenoid_pads[i], solenoid_active_state[i]);
+                }
+            } else {
+                if (solenoid_buzzing[i]) {
+                    solenoid_buzzing[i] = false;
+                    writePin(solenoid_pads[i], !solenoid_active_state[i]);
+                }
             }
         }
     }
 }
 
+/**
+ * @brief Initial configuration for solenoids
+ *
+ */
 void solenoid_setup(void) {
-    SOLENOID_PIN_WRITE_INACTIVE();
-    setPinOutput(SOLENOID_PIN);
-    if ((!HAPTIC_OFF_IN_LOW_POWER) || (usb_device_state == USB_DEVICE_STATE_CONFIGURED)) {
-        solenoid_fire();
+#ifdef SOLENOID_PINS_ACTIVE_STATE
+    bool    state_temp[] = SOLENOID_PINS_ACTIVE_STATE;
+    uint8_t bound_check  = (sizeof(state_temp) / sizeof(bool));
+#endif
+
+    for (uint8_t i = 0; i < NUMBER_OF_SOLENOIDS; i++) {
+#ifdef SOLENOID_PINS_ACTIVE_STATE
+        solenoid_active_state[i] = (bound_check - i) ? state_temp[i] : high;
+#else
+        solenoid_active_state[i] = high;
+#endif
+        writePin(solenoid_pads[i], !solenoid_active_state[i]);
+        setPinOutput(solenoid_pads[i]);
+        if ((!HAPTIC_OFF_IN_LOW_POWER) || (usb_device_state == USB_DEVICE_STATE_CONFIGURED)) {
+            solenoid_fire(i);
+        }
     }
 }
 
+/**
+ * @brief stops solenoids prior to device reboot, to prevent them from being locked on
+ *
+ */
 void solenoid_shutdown(void) {
-    SOLENOID_PIN_WRITE_INACTIVE();
+    for (uint8_t i = 0; i < NUMBER_OF_SOLENOIDS; i++) {
+        writePin(solenoid_pads[i], !solenoid_active_state[i]);
+    }
 }
diff --git a/drivers/haptic/solenoid.h b/drivers/haptic/solenoid.h
index 653148154f..952f86e922 100644
--- a/drivers/haptic/solenoid.h
+++ b/drivers/haptic/solenoid.h
@@ -45,26 +45,24 @@
 #    define SOLENOID_BUZZ_NONACTUATED SOLENOID_MIN_DWELL
 #endif
 
-#ifndef SOLENOID_PIN
-#    error SOLENOID_PIN not defined
+#ifndef SOLENOID_PINS
+#    ifdef SOLENOID_PIN
+#        define SOLENOID_PINS \
+            { SOLENOID_PIN }
+#    else
+#        error SOLENOID_PINS array not defined
+#    endif
 #endif
 
-#ifdef SOLENOID_PIN_ACTIVE_LOW
-#    define SOLENOID_PIN_WRITE_ACTIVE() writePinLow(SOLENOID_PIN)
-#    define SOLENOID_PIN_WRITE_INACTIVE() writePinHigh(SOLENOID_PIN)
-#else
-#    define SOLENOID_PIN_WRITE_ACTIVE() writePinHigh(SOLENOID_PIN)
-#    define SOLENOID_PIN_WRITE_INACTIVE() writePinLow(SOLENOID_PIN)
-#endif
-
-void solenoid_buzz_on(void);
+void solenoidbuzz_on(void);
 void solenoid_buzz_off(void);
-void solenoid_set_buzz(int buzz);
+void solenoid_set_buzz(uint8_t buzz);
 
 void solenoid_set_dwell(uint8_t dwell);
 
-void solenoid_stop(void);
-void solenoid_fire(void);
+void solenoid_stop(uint8_t index);
+void solenoid_fire(uint8_t index);
+void solenoid_fire_handler(void);
 
 void solenoid_check(void);
 
diff --git a/drivers/lcd/hd44780.c b/drivers/lcd/hd44780.c
new file mode 100644
index 0000000000..c988ebe56c
--- /dev/null
+++ b/drivers/lcd/hd44780.c
@@ -0,0 +1,284 @@
+/*
+Copyright 2022
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "hd44780.h"
+#include "gpio.h"
+#include "progmem.h"
+#include "wait.h"
+
+#ifndef HD44780_DATA_PINS
+#    error hd44780: no data pins defined!
+#endif
+
+#ifndef HD44780_RS_PIN
+#    error hd44780: no RS pin defined!
+#endif
+
+#ifndef HD44780_RW_PIN
+#    error hd44780: no R/W pin defined!
+#endif
+
+#ifndef HD44780_E_PIN
+#    error hd44780: no E pin defined!
+#endif
+
+static const pin_t data_pins[4] = HD44780_DATA_PINS;
+
+#ifndef HD44780_DISPLAY_COLS
+#    define HD44780_DISPLAY_COLS 16
+#endif
+
+#ifndef HD44780_DISPLAY_LINES
+#    define HD44780_DISPLAY_LINES 2
+#endif
+
+#ifndef HD44780_DDRAM_LINE0_ADDR
+#    define HD44780_DDRAM_LINE0_ADDR 0x00
+#endif
+#ifndef HD44780_DDRAM_LINE1_ADDR
+#    define HD44780_DDRAM_LINE1_ADDR 0x40
+#endif
+
+#define HD44780_INIT_DELAY_MS 16
+#define HD44780_ENABLE_DELAY_US 1
+
+static void hd44780_latch(void) {
+    writePinHigh(HD44780_E_PIN);
+    wait_us(HD44780_ENABLE_DELAY_US);
+    writePinLow(HD44780_E_PIN);
+}
+
+void hd44780_write(uint8_t data, bool isData) {
+    writePin(HD44780_RS_PIN, isData);
+    writePinLow(HD44780_RW_PIN);
+
+    for (int i = 0; i < 4; i++) {
+        setPinOutput(data_pins[i]);
+    }
+
+    // Write high nibble
+    for (int i = 0; i < 4; i++) {
+        writePin(data_pins[i], (data >> 4) & (1 << i));
+    }
+    hd44780_latch();
+
+    // Write low nibble
+    for (int i = 0; i < 4; i++) {
+        writePin(data_pins[i], data & (1 << i));
+    }
+    hd44780_latch();
+
+    for (int i = 0; i < 4; i++) {
+        writePinHigh(data_pins[i]);
+    }
+}
+
+uint8_t hd44780_read(bool isData) {
+    uint8_t data = 0;
+
+    writePin(HD44780_RS_PIN, isData);
+    writePinHigh(HD44780_RW_PIN);
+
+    for (int i = 0; i < 4; i++) {
+        setPinInput(data_pins[i]);
+    }
+
+    writePinHigh(HD44780_E_PIN);
+    wait_us(HD44780_ENABLE_DELAY_US);
+
+    // Read high nibble
+    for (int i = 0; i < 4; i++) {
+        data |= (readPin(data_pins[i]) << i);
+    }
+
+    data <<= 4;
+
+    writePinLow(HD44780_E_PIN);
+    wait_us(HD44780_ENABLE_DELAY_US);
+    writePinHigh(HD44780_E_PIN);
+    wait_us(HD44780_ENABLE_DELAY_US);
+
+    // Read low nibble
+    for (int i = 0; i < 4; i++) {
+        data |= (readPin(data_pins[i]) << i);
+    }
+
+    writePinLow(HD44780_E_PIN);
+
+    return data;
+}
+
+bool hd44780_busy(void) {
+    return hd44780_read(false) & HD44780_BUSY_FLAG;
+}
+
+void hd44780_command(uint8_t command) {
+    while (hd44780_busy())
+        ;
+    hd44780_write(command, false);
+}
+
+void hd44780_data(uint8_t data) {
+    while (hd44780_busy())
+        ;
+    hd44780_write(data, true);
+}
+
+void hd44780_clear(void) {
+    hd44780_command(HD44780_CMD_CLEAR_DISPLAY);
+}
+
+void hd44780_home(void) {
+    hd44780_command(HD44780_CMD_RETURN_HOME);
+}
+
+void hd44780_on(bool cursor, bool blink) {
+    if (cursor) {
+        if (blink) {
+            hd44780_command(HD44780_CMD_DISPLAY | HD44780_DISPLAY_ON | HD44780_DISPLAY_CURSOR | HD44780_DISPLAY_BLINK);
+        } else {
+            hd44780_command(HD44780_CMD_DISPLAY | HD44780_DISPLAY_ON | HD44780_DISPLAY_CURSOR);
+        }
+    } else {
+        hd44780_command(HD44780_CMD_DISPLAY | HD44780_DISPLAY_ON);
+    }
+}
+
+void hd44780_off() {
+    hd44780_command(HD44780_CMD_DISPLAY);
+}
+
+void hd44780_set_cgram_address(uint8_t address) {
+    hd44780_command(HD44780_CMD_SET_CGRAM_ADDRESS + (address & 0x3F));
+}
+
+void hd44780_set_ddram_address(uint8_t address) {
+    hd44780_command(HD44780_CMD_SET_DDRAM_ADDRESS + (address & 0x7F));
+}
+
+void hd44780_init(bool cursor, bool blink) {
+    setPinOutput(HD44780_RS_PIN);
+    setPinOutput(HD44780_RW_PIN);
+    setPinOutput(HD44780_E_PIN);
+
+    for (int i = 0; i < 4; i++) {
+        setPinOutput(data_pins[i]);
+    }
+
+    wait_ms(HD44780_INIT_DELAY_MS);
+
+    // Manually configure for 4-bit mode - can't use hd44780_command() yet
+    // HD44780U datasheet, Fig. 24 (p46)
+    writePinHigh(data_pins[0]); // Function set
+    writePinHigh(data_pins[1]); // DL = 1
+    hd44780_latch();
+    wait_ms(5);
+    // Send again
+    hd44780_latch();
+    wait_us(64);
+    // And again (?)
+    hd44780_latch();
+    wait_us(64);
+
+    writePinLow(data_pins[0]); // DL = 0
+    hd44780_latch();
+    wait_us(64);
+
+#if HD44780_DISPLAY_LINES == 1
+    hd44780_command(HD44780_CMD_FUNCTION); // 4 bit, 1 line, 5x8 dots
+#else
+    hd44780_command(HD44780_CMD_FUNCTION | HD44780_FUNCTION_2_LINES); // 4 bit, 2 lines, 5x8 dots
+#endif
+    hd44780_on(cursor, blink);
+    hd44780_clear();
+    hd44780_home();
+    hd44780_command(HD44780_CMD_ENTRY_MODE | HD44780_ENTRY_MODE_INC);
+}
+
+void hd44780_set_cursor(uint8_t col, uint8_t line) {
+    register uint8_t address = col;
+
+#if HD44780_DISPLAY_LINES == 1
+    address += HD44780_DDRAM_LINE0_ADDR;
+#elif HD44780_DISPLAY_LINES == 2
+    if (line == 0) {
+        address += HD44780_DDRAM_LINE0_ADDR;
+    } else {
+        address += HD44780_DDRAM_LINE1_ADDR;
+    }
+#endif
+
+    hd44780_set_ddram_address(address);
+}
+
+void hd44780_define_char(uint8_t index, uint8_t *data) {
+    hd44780_set_cgram_address((index & 0x7) << 3);
+    for (uint8_t i = 0; i < 8; i++) {
+        hd44780_data(data[i]);
+    }
+}
+
+void hd44780_putc(char c) {
+    while (hd44780_busy())
+        ;
+    uint8_t current_position = hd44780_read(false);
+
+    if (c == '\n') {
+        hd44780_set_cursor(0, current_position < HD44780_DDRAM_LINE1_ADDR ? 1 : 0);
+    } else {
+#if defined(HD44780_WRAP_LINES)
+#    if HD44780_DISPLAY_LINES == 1
+        if (current_position == HD44780_DDRAM_LINE0_ADDR + HD44780_DISPLAY_COLS) {
+            // Go to start of line
+            hd44780_set_cursor(0, 0);
+        }
+#    elif HD44780_DISPLAY_LINES == 2
+        if (current_position == HD44780_DDRAM_LINE0_ADDR + HD44780_DISPLAY_COLS) {
+            // Go to start of second line
+            hd44780_set_cursor(0, 1);
+        } else if (current_position == HD44780_DDRAM_LINE1_ADDR + HD44780_DISPLAY_COLS) {
+            // Go to start of first line
+            hd44780_set_cursor(0, 0);
+        }
+#    endif
+#endif
+        hd44780_data(c);
+    }
+}
+
+void hd44780_puts(const char *s) {
+    register char c;
+    while ((c = *s++)) {
+        hd44780_putc(c);
+    }
+}
+
+#if defined(__AVR__)
+void hd44780_define_char_P(uint8_t index, const uint8_t *data) {
+    hd44780_set_cgram_address(index << 3);
+    for (uint8_t i = 0; i < 8; i++) {
+        hd44780_data(pgm_read_byte(data++));
+    }
+}
+
+void hd44780_puts_P(const char *s) {
+    register char c;
+    while ((c = pgm_read_byte(s++))) {
+        hd44780_putc(c);
+    }
+}
+#endif
diff --git a/drivers/lcd/hd44780.h b/drivers/lcd/hd44780.h
new file mode 100644
index 0000000000..9e43339344
--- /dev/null
+++ b/drivers/lcd/hd44780.h
@@ -0,0 +1,220 @@
+/*
+Copyright 2022
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/**
+ * \defgroup hd44780
+ *
+ * HD44780 Character LCD Driver
+ * \{
+ */
+
+/*
+ * HD44780 instructions
+ * https://www.sparkfun.com/datasheets/LCD/HD44780.pdf
+ * Table 6 (p24)
+ */
+// Clear display
+#define HD44780_CMD_CLEAR_DISPLAY 0x01
+// Return home
+#define HD44780_CMD_RETURN_HOME 0x02
+// Entry mode set
+#define HD44780_CMD_ENTRY_MODE 0x04
+#define HD44780_ENTRY_MODE_INC 0x02   // I/D
+#define HD44780_ENTRY_MODE_SHIFT 0x01 // S
+// Display on/off control
+#define HD44780_CMD_DISPLAY 0x08
+#define HD44780_DISPLAY_ON 0x04     // D
+#define HD44780_DISPLAY_CURSOR 0x02 // C
+#define HD44780_DISPLAY_BLINK 0x01  // B
+// Cursor or display shift
+#define HD44780_CMD_MOVE 0x10
+#define HD44780_MOVE_DISPLAY 0x08 // S/C
+#define HD44780_MOVE_RIGHT 0x04   // R/L
+// Function set
+#define HD44780_CMD_FUNCTION 0x20
+#define HD44780_FUNCTION_8_BIT 0x10     // DL
+#define HD44780_FUNCTION_2_LINES 0x08   // N
+#define HD44780_FUNCTION_5X10_DOTS 0x04 // F
+// Set CGRAM address
+#define HD44780_CMD_SET_CGRAM_ADDRESS 0x40
+// Set DDRAM address
+#define HD44780_CMD_SET_DDRAM_ADDRESS 0x80
+
+// Bitmask for busy flag when reading
+#define HD44780_BUSY_FLAG 0x80
+
+/**
+ * \brief Write a byte to the display.
+ *
+ * \param data The byte to send to the display.
+ * \param isData Whether the byte is an instruction or character data.
+ */
+void hd44780_write(uint8_t data, bool isData);
+
+/**
+ * \brief Read a byte from the display.
+ *
+ * \param isData Whether to read the current cursor position, or the character at the cursor.
+ *
+ * \return If `isData` is `true`, the returned byte will be the character at the current DDRAM address. Otherwise, it will be the current DDRAM address and the busy flag.
+ */
+uint8_t hd44780_read(bool isData);
+
+/**
+ * \brief Indicates whether the display is currently processing, and cannot accept instructions.
+ *
+ * \return `true` if the display is busy.
+ */
+bool hd44780_busy(void);
+
+/**
+ * \brief Send a command to the display. Refer to the datasheet for the valid commands.
+ *
+ * This function waits for the display to clear the busy flag before sending the command.
+ *
+ * \param command The command to send.
+ */
+void hd44780_command(uint8_t command);
+
+/**
+ * \brief Send a byte of data to the display.
+ *
+ * This function waits for the display to clear the busy flag before sending the data.
+ *
+ * \param data The byte of data to send.
+ */
+void hd44780_data(uint8_t data);
+
+/**
+ * \brief Clear the display.
+ *
+ * This function is called on init.
+ */
+void hd44780_clear(void);
+
+/**
+ * \brief Move the cursor to the home position.
+ *
+ * This function is called on init.
+ */
+void hd44780_home(void);
+
+/**
+ * \brief Turn the display on, and/or set the cursor position.
+ *
+ * This function is called on init.
+ *
+ * \param cursor Whether to show the cursor.
+ * \param blink Whether to blink the cursor, if shown.
+ */
+void hd44780_on(bool cursor, bool blink);
+
+/**
+ * \brief Turn the display off.
+ */
+void hd44780_off(void);
+
+/**
+ * \brief Set the CGRAM address.
+ *
+ * This function is used when defining custom characters.
+ *
+ * \param address The CGRAM address to move to, from `0x00` to `0x3F`.
+ */
+void hd44780_set_cgram_address(uint8_t address);
+
+/**
+ * \brief Set the DDRAM address.
+ *
+ * This function is used when printing characters to the display, and setting the cursor.
+ *
+ * \param address The DDRAM address to move to, from `0x00` to `0x7F`.
+ */
+void hd44780_set_ddram_address(uint8_t address);
+
+/**
+ * \brief Initialize the display.
+ *
+ * This function should be called only once, before any of the other functions can be called.
+ *
+ * \param cursor Whether to show the cursor.
+ * \param blink Whether to blink the cursor, if shown.
+ */
+void hd44780_init(bool cursor, bool blink);
+
+/**
+ * \brief Move the cursor to the specified position on the display.
+ *
+ * \param col The column number to move to, from 0 to 15 on 16x2 displays.
+ * \param line The line number to move to, either 0 or 1 on 16x2 displays.
+ */
+void hd44780_set_cursor(uint8_t col, uint8_t line);
+
+/**
+ * \brief Define a custom character.
+ *
+ * \param index The index of the custom character to define, from 0 to 7.
+ * \param data An array of 8 bytes containing the 5-bit row data of the character, where the first byte is the topmost row, and the least significant bit of each byte is the rightmost column.
+ */
+void hd44780_define_char(uint8_t index, uint8_t *data);
+
+/**
+ * \brief Print a character to the display. The newline character will move the cursor to the start of the next line.
+ *
+ * The exact character shown may depend on the ROM code of your particular display - refer to the datasheet for the full character set.
+ *
+ * \param c The character to print.
+ */
+void hd44780_putc(char c);
+
+/**
+ * \brief Print a string of characters to the display.
+ *
+ * \param s The string to print.
+ */
+void hd44780_puts(const char *s);
+
+#if defined(__AVR__) || defined(__DOXYGEN__)
+/**
+ * \brief Define a custom character from PROGMEM.
+ *
+ * On ARM devices, this function is simply an alias of hd44780_define_char().
+ *
+ * \param index The index of the custom character to define, from 0 to 7.
+ * \param data A PROGMEM array of 8 bytes containing the 5-bit row data of the character, where the first byte is the topmost row, and the least significant bit of each byte is the rightmost column.
+ */
+void hd44780_define_char_P(uint8_t index, const uint8_t *data);
+
+/**
+ * \brief Print a string of characters from PROGMEM to the display.
+ *
+ * On ARM devices, this function is simply an alias of hd44780_puts().
+ *
+ * \param s The PROGMEM string to print.
+ */
+void hd44780_puts_P(const char *s);
+#else
+#    define hd44780_define_char_P(index, data) hd44780_define_char(index, data)
+#    define hd44780_puts_P(s) hd44780_puts(s)
+#endif
+
+/** \} */
diff --git a/drivers/led/issi/is31fl3737.c b/drivers/led/issi/is31fl3737.c
index 9f2a13de45..bce0c34b2c 100644
--- a/drivers/led/issi/is31fl3737.c
+++ b/drivers/led/issi/is31fl3737.c
@@ -57,6 +57,10 @@
 #    define ISSI_PERSISTENCE 0
 #endif
 
+#ifndef ISSI_PWM_FREQUENCY
+#    define ISSI_PWM_FREQUENCY 0b000 // PFS - IS31FL3737B only
+#endif
+
 #ifndef ISSI_SWPULLUP
 #    define ISSI_SWPULLUP PUR_0R
 #endif
@@ -159,7 +163,7 @@ void IS31FL3737_init(uint8_t addr) {
     // Set global current to maximum.
     IS31FL3737_write_register(addr, ISSI_REG_GLOBALCURRENT, 0xFF);
     // Disable software shutdown.
-    IS31FL3737_write_register(addr, ISSI_REG_CONFIGURATION, 0x01);
+    IS31FL3737_write_register(addr, ISSI_REG_CONFIGURATION, ((ISSI_PWM_FREQUENCY & 0b111) << 3) | 0x01);
 
     // Wait 10ms to ensure the device has woken up.
     wait_ms(10);
diff --git a/drivers/painter/comms/qp_comms_spi.c b/drivers/painter/comms/qp_comms_spi.c
new file mode 100644
index 0000000000..e644ba9f84
--- /dev/null
+++ b/drivers/painter/comms/qp_comms_spi.c