diff --git a/builddefs/common_features.mk b/builddefs/common_features.mk
index db9b580286..08d186d656 100644
--- a/builddefs/common_features.mk
+++ b/builddefs/common_features.mk
@@ -219,6 +219,21 @@ else
endif
endif
+VALID_FLASH_DRIVER_TYPES := spi
+FLASH_DRIVER ?= no
+ifneq ($(strip $(FLASH_DRIVER)), no)
+ ifeq ($(filter $(FLASH_DRIVER),$(VALID_FLASH_DRIVER_TYPES)),)
+ $(error FLASH_DRIVER="$(FLASH_DRIVER)" is not a valid FLASH driver)
+ else
+ OPT_DEFS += -DFLASH_ENABLE
+ ifeq ($(strip $(FLASH_DRIVER)), spi)
+ OPT_DEFS += -DFLASH_DRIVER -DFLASH_SPI
+ COMMON_VPATH += $(DRIVER_PATH)/flash
+ SRC += flash_spi.c
+ endif
+ endif
+endif
+
RGBLIGHT_ENABLE ?= no
VALID_RGBLIGHT_TYPES := WS2812 APA102 custom
diff --git a/docs/flash_driver.md b/docs/flash_driver.md
new file mode 100644
index 0000000000..fa7fed5171
--- /dev/null
+++ b/docs/flash_driver.md
@@ -0,0 +1,24 @@
+# FLASH Driver Configuration :id=flash-driver-configuration
+
+The FLASH driver can be swapped out depending on the needs of the keyboard, or whether extra hardware is present.
+
+Driver | Description
+-----------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+`FLASH_DRIVER = spi` | Supports writing to almost all NOR Flash chips. See the driver section below.
+
+
+## SPI FLASH Driver Configuration :id=spi-flash-driver-configuration
+
+Currently QMK supports almost all NOR Flash chips over SPI. As such, requires a working spi_master driver configuration. You can override the driver configuration via your config.h:
+
+`config.h` override | Description | Default Value
+-----------------------------------------------|--------------------------------------------------------------------------------------|-----------------
+`#define EXTERNAL_FLASH_SPI_SLAVE_SELECT_PIN` | SPI Slave select pin in order to inform that the FLASH is currently being addressed | _none_
+`#define EXTERNAL_FLASH_SPI_CLOCK_DIVISOR` | Clock divisor used to divide the peripheral clock to derive the SPI frequency | `8`
+`#define EXTERNAL_FLASH_PAGE_SIZE` | The Page size of the FLASH in bytes, as specified in the datasheet | `256`
+`#define EXTERNAL_FLASH_SECTOR_SIZE` | The sector size of the FLASH in bytes, as specified in the datasheet | `(4 * 1024)`
+`#define EXTERNAL_FLASH_BLOCK_SIZE` | The block size of the FLASH in bytes, as specified in the datasheet | `(64 * 1024)`
+`#define EXTERNAL_FLASH_SIZE` | The total size of the FLASH in bytes, as specified in the datasheet | `(512 * 1024)`
+`#define EXTERNAL_FLASH_ADDRESS_SIZE` | The Flash address size in bytes, as specified in datasheet | `3`
+
+!> All the above default configurations are based on MX25L4006E NOR Flash.
diff --git a/drivers/flash/flash_spi.c b/drivers/flash/flash_spi.c
new file mode 100644
index 0000000000..2fa8891e38
--- /dev/null
+++ b/drivers/flash/flash_spi.c
@@ -0,0 +1,372 @@
+/*
+Copyright (C) 2021 Westberry Technology (ChangZhou) Corp., Ltd
+
+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 .
+*/
+
+#include
+
+#include "util.h"
+#include "wait.h"
+#include "debug.h"
+#include "timer.h"
+#include "flash_spi.h"
+#include "spi_master.h"
+
+/*
+ The time-out time of spi flash transmission.
+*/
+#ifndef EXTERNAL_FLASH_SPI_TIMEOUT
+# define EXTERNAL_FLASH_SPI_TIMEOUT 1000
+#endif
+
+/* ID comands */
+#define FLASH_CMD_RDID 0x9F /* RDID (Read Identification) */
+#define FLASH_CMD_RES 0xAB /* RES (Read Electronic ID) */
+#define FLASH_CMD_REMS 0x90 /* REMS (Read Electronic & Device ID) */
+
+/* register comands */
+#define FLASH_CMD_WRSR 0x01 /* WRSR (Write Status register) */
+#define FLASH_CMD_RDSR 0x05 /* RDSR (Read Status register) */
+
+/* READ comands */
+#define FLASH_CMD_READ 0x03 /* READ (1 x I/O) */
+#define FLASH_CMD_FASTREAD 0x0B /* FAST READ (Fast read data) */
+#define FLASH_CMD_DREAD 0x3B /* DREAD (1In/2 Out fast read) */
+
+/* Program comands */
+#define FLASH_CMD_WREN 0x06 /* WREN (Write Enable) */
+#define FLASH_CMD_WRDI 0x04 /* WRDI (Write Disable) */
+#define FLASH_CMD_PP 0x02 /* PP (page program) */
+
+/* Erase comands */
+#define FLASH_CMD_SE 0x20 /* SE (Sector Erase) */
+#define FLASH_CMD_BE 0xD8 /* BE (Block Erase) */
+#define FLASH_CMD_CE 0x60 /* CE (Chip Erase) hex code: 60 or C7 */
+
+/* Mode setting comands */
+#define FLASH_CMD_DP 0xB9 /* DP (Deep Power Down) */
+#define FLASH_CMD_RDP 0xAB /* RDP (Release form Deep Power Down) */
+
+/* Status register */
+#define FLASH_FLAG_WIP 0x01 /* Write in progress bit */
+#define FLASH_FLAG_WEL 0x02 /* Write enable latch bit */
+
+// #define DEBUG_FLASH_SPI_OUTPUT
+
+static bool spi_flash_start(void) { return spi_start(EXTERNAL_FLASH_SPI_SLAVE_SELECT_PIN, EXTERNAL_FLASH_SPI_LSBFIRST, EXTERNAL_FLASH_SPI_MODE, EXTERNAL_FLASH_SPI_CLOCK_DIVISOR); }
+
+static flash_status_t spi_flash_wait_while_busy(void) {
+ uint32_t deadline = timer_read32() + EXTERNAL_FLASH_SPI_TIMEOUT;
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+ uint8_t retval;
+
+ do {
+ bool res = spi_flash_start();
+ if (!res) {
+ dprint("Failed to start SPI! [spi flash wait while busy]\n");
+ return FLASH_STATUS_ERROR;
+ }
+
+ spi_write(FLASH_CMD_RDSR);
+
+ retval = (uint8_t)spi_read();
+
+ spi_stop();
+
+ if (timer_read32() >= deadline) {
+ response = FLASH_STATUS_TIMEOUT;
+ break;
+ }
+ } while (retval & FLASH_FLAG_WIP);
+
+ return response;
+}
+
+static flash_status_t spi_flash_write_enable(void) {
+ bool res = spi_flash_start();
+ if (!res) {
+ dprint("Failed to start SPI! [spi flash write enable]\n");
+ return FLASH_STATUS_ERROR;
+ }
+
+ spi_write(FLASH_CMD_WREN);
+
+ spi_stop();
+
+ return FLASH_STATUS_SUCCESS;
+}
+
+static flash_status_t spi_flash_write_disable(void) {
+ bool res = spi_flash_start();
+ if (!res) {
+ dprint("Failed to start SPI! [spi flash write disable]\n");
+ return FLASH_STATUS_ERROR;
+ }
+
+ spi_write(FLASH_CMD_WRDI);
+
+ spi_stop();
+
+ return FLASH_STATUS_SUCCESS;
+}
+
+/* This function is used for read transfer, write transfer and erase transfer. */
+static flash_status_t spi_flash_transaction(uint8_t cmd, uint32_t addr, uint8_t *data, size_t len) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+ uint8_t buffer[EXTERNAL_FLASH_ADDRESS_SIZE + 1];
+
+ buffer[0] = cmd;
+ for (int i = 0; i < EXTERNAL_FLASH_ADDRESS_SIZE; ++i) {
+ buffer[EXTERNAL_FLASH_ADDRESS_SIZE - i] = addr & 0xFF;
+ addr >>= 8;
+ }
+
+ bool res = spi_flash_start();
+ if (!res) {
+ dprint("Failed to start SPI! [spi flash transmit]\n");
+ return FLASH_STATUS_ERROR;
+ }
+
+ response = spi_transmit(buffer, sizeof(buffer));
+
+ if ((!response) && (data != NULL)) {
+ switch (cmd) {
+ case FLASH_CMD_READ:
+ response = spi_receive(data, len);
+ break;
+ case FLASH_CMD_PP:
+ response = spi_transmit(data, len);
+ break;
+ default:
+ response = FLASH_STATUS_ERROR;
+ break;
+ }
+ }
+
+ spi_stop();
+
+ return response;
+}
+
+void flash_init(void) { spi_init(); }
+
+flash_status_t flash_erase_chip(void) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase chip]\n");
+ return response;
+ }
+
+ /* Enable writes. */
+ response = spi_flash_write_enable();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write-enable! [spi flash erase chip]\n");
+ return response;
+ }
+
+ /* Erase Chip. */
+ bool res = spi_flash_start();
+ if (!res) {
+ dprint("Failed to start SPI! [spi flash erase chip]\n");
+ return FLASH_STATUS_ERROR;
+ }
+ spi_write(FLASH_CMD_CE);
+ spi_stop();
+
+ /* Wait for the write-in-progress bit to be cleared.*/
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase chip]\n");
+ return response;
+ }
+
+ return response;
+}
+
+flash_status_t flash_erase_sector(uint32_t addr) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+
+ /* Check that the address exceeds the limit. */
+ if ((addr + (EXTERNAL_FLASH_SECTOR_SIZE)) >= (EXTERNAL_FLASH_SIZE) || ((addr % (EXTERNAL_FLASH_SECTOR_SIZE)) != 0)) {
+ dprintf("Flash erase sector address over limit! [addr:0x%x]\n", (uint32_t)addr);
+ return FLASH_STATUS_ERROR;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase sector]\n");
+ return response;
+ }
+
+ /* Enable writes. */
+ response = spi_flash_write_enable();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write-enable! [spi flash erase sector]\n");
+ return response;
+ }
+
+ /* Erase Sector. */
+ response = spi_flash_transaction(FLASH_CMD_SE, addr, NULL, 0);
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to erase sector! [spi flash erase sector]\n");
+ return response;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared.*/
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase sector]\n");
+ return response;
+ }
+
+ return response;
+}
+
+flash_status_t flash_erase_block(uint32_t addr) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+
+ /* Check that the address exceeds the limit. */
+ if ((addr + (EXTERNAL_FLASH_BLOCK_SIZE)) >= (EXTERNAL_FLASH_SIZE) || ((addr % (EXTERNAL_FLASH_BLOCK_SIZE)) != 0)) {
+ dprintf("Flash erase block address over limit! [addr:0x%x]\n", (uint32_t)addr);
+ return FLASH_STATUS_ERROR;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase block]\n");
+ return response;
+ }
+
+ /* Enable writes. */
+ response = spi_flash_write_enable();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write-enable! [spi flash erase block]\n");
+ return response;
+ }
+
+ /* Erase Block. */
+ response = spi_flash_transaction(FLASH_CMD_BE, addr, NULL, 0);
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to erase block! [spi flash erase block]\n");
+ return response;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared.*/
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash erase block]\n");
+ return response;
+ }
+
+ return response;
+}
+
+flash_status_t flash_read_block(uint32_t addr, void *buf, size_t len) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+ uint8_t * read_buf = (uint8_t *)buf;
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash read block]\n");
+ memset(read_buf, 0, len);
+ return response;
+ }
+
+ /* Perform read. */
+ response = spi_flash_transaction(FLASH_CMD_READ, addr, read_buf, len);
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to read block! [spi flash read block]\n");
+ memset(read_buf, 0, len);
+ return response;
+ }
+
+#if defined(CONSOLE_ENABLE) && defined(DEBUG_FLASH_SPI_OUTPUT)
+ dprintf("[SPI FLASH R] 0x%08lX: ", addr);
+ for (size_t i = 0; i < len; ++i) {
+ dprintf(" %02X", (int)(((uint8_t *)read_buf)[i]));
+ }
+ dprintf("\n");
+#endif // DEBUG_FLASH_SPI_OUTPUT
+
+ return response;
+}
+
+flash_status_t flash_write_block(uint32_t addr, const void *buf, size_t len) {
+ flash_status_t response = FLASH_STATUS_SUCCESS;
+ uint8_t * write_buf = (uint8_t *)buf;
+
+ while (len > 0) {
+ uint32_t page_offset = addr % EXTERNAL_FLASH_PAGE_SIZE;
+ size_t write_length = EXTERNAL_FLASH_PAGE_SIZE - page_offset;
+ if (write_length > len) {
+ write_length = len;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash write block]\n");
+ return response;
+ }
+
+ /* Enable writes. */
+ response = spi_flash_write_enable();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write-enable! [spi flash write block]\n");
+ return response;
+ }
+
+#if defined(CONSOLE_ENABLE) && defined(DEBUG_FLASH_SPI_OUTPUT)
+ dprintf("[SPI FLASH W] 0x%08lX: ", addr);
+ for (size_t i = 0; i < write_length; i++) {
+ dprintf(" %02X", (int)(uint8_t)(write_buf[i]));
+ }
+ dprintf("\n");
+#endif // DEBUG_FLASH_SPI_OUTPUT
+
+ /* Perform the write. */
+ response = spi_flash_transaction(FLASH_CMD_PP, addr, write_buf, write_length);
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write block! [spi flash write block]\n");
+ return response;
+ }
+
+ write_buf += write_length;
+ addr += write_length;
+ len -= write_length;
+ }
+
+ /* Wait for the write-in-progress bit to be cleared. */
+ response = spi_flash_wait_while_busy();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to check WIP flag! [spi flash write block]\n");
+ return response;
+ }
+
+ /* Disable writes. */
+ response = spi_flash_write_disable();
+ if (response != FLASH_STATUS_SUCCESS) {
+ dprint("Failed to write-disable! [spi flash write block]\n");
+ return response;
+ }
+
+ return response;
+}
diff --git a/drivers/flash/flash_spi.h b/drivers/flash/flash_spi.h
new file mode 100644
index 0000000000..abe95e955e
--- /dev/null
+++ b/drivers/flash/flash_spi.h
@@ -0,0 +1,136 @@
+/*
+Copyright (C) 2021 Westberry Technology (ChangZhou) Corp., Ltd
+
+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 .
+*/
+
+#pragma once
+
+/* All the following default configurations are based on MX25L4006E Nor FLASH. */
+
+/*
+ The slave select pin of the FLASH.
+ This needs to be a normal GPIO pin_t value, such as B14.
+*/
+#ifndef EXTERNAL_FLASH_SPI_SLAVE_SELECT_PIN
+# error "No chip select pin defined -- missing EXTERNAL_FLASH_SPI_SLAVE_SELECT_PIN"
+#endif
+
+/*
+ The clock divisor for SPI to ensure that the MCU is within the
+ specifications of the FLASH chip. Generally this will be PCLK divided by
+ the intended divisor -- check your clock settings and the datasheet of
+ your FLASH.
+*/
+#ifndef EXTERNAL_FLASH_SPI_CLOCK_DIVISOR
+# ifdef __AVR__
+# define EXTERNAL_FLASH_SPI_CLOCK_DIVISOR 4
+# else
+# define EXTERNAL_FLASH_SPI_CLOCK_DIVISOR 8
+# endif
+#endif
+
+/*
+ The SPI mode to communicate with the FLASH.
+*/
+#ifndef EXTERNAL_FLASH_SPI_MODE
+# define EXTERNAL_FLASH_SPI_MODE 0
+#endif
+
+/*
+ Whether or not the SPI communication between the MCU and FLASH should be
+ LSB-first.
+*/
+#ifndef EXTERNAL_FLASH_SPI_LSBFIRST
+# define EXTERNAL_FLASH_SPI_LSBFIRST false
+#endif
+
+/*
+ The Flash address size in bytes, as specified in datasheet.
+*/
+#ifndef EXTERNAL_FLASH_ADDRESS_SIZE
+# define EXTERNAL_FLASH_ADDRESS_SIZE 3
+#endif
+
+/*
+ The page size of the FLASH in bytes, as specified in the datasheet.
+*/
+#ifndef EXTERNAL_FLASH_PAGE_SIZE
+# define EXTERNAL_FLASH_PAGE_SIZE 256
+#endif
+
+/*
+ The sector size of the FLASH in bytes, as specified in the datasheet.
+*/
+#ifndef EXTERNAL_FLASH_SECTOR_SIZE
+# define EXTERNAL_FLASH_SECTOR_SIZE (4 * 1024)
+#endif
+
+/*
+ The block size of the FLASH in bytes, as specified in the datasheet.
+*/
+#ifndef EXTERNAL_FLASH_BLOCK_SIZE
+# define EXTERNAL_FLASH_BLOCK_SIZE (64 * 1024)
+#endif
+
+/*
+ The total size of the FLASH in bytes, as specified in the datasheet.
+*/
+#ifndef EXTERNAL_FLASH_SIZE
+# define EXTERNAL_FLASH_SIZE (512 * 1024)
+#endif
+
+/*
+ The block count of the FLASH, calculated by total FLASH size and block size.
+*/
+#define EXTERNAL_FLASH_BLOCK_COUNT ((EXTERNAL_FLASH_SIZE) / (EXTERNAL_FLASH_BLOCK_SIZE))
+
+/*
+ The sector count of the FLASH, calculated by total FLASH size and sector size.
+*/
+#define EXTERNAL_FLASH_SECTOR_COUNT ((EXTERNAL_FLASH_SIZE) / (EXTERNAL_FLASH_SECTOR_SIZE))
+
+/*
+ The page count of the FLASH, calculated by total FLASH size and page size.
+*/
+#define EXTERNAL_FLASH_PAGE_COUNT ((EXTERNAL_FLASH_SIZE) / (EXTERNAL_FLASH_PAGE_SIZE))
+
+typedef int16_t flash_status_t;
+
+#define FLASH_STATUS_SUCCESS (0)
+#define FLASH_STATUS_ERROR (-1)
+#define FLASH_STATUS_TIMEOUT (-2)
+#define FLASH_STATUS_BAD_ADDRESS (-3)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include
+
+void flash_init(void);
+
+flash_status_t flash_erase_chip(void);
+
+flash_status_t flash_erase_block(uint32_t addr);
+
+flash_status_t flash_erase_sector(uint32_t addr);
+
+flash_status_t flash_read_block(uint32_t addr, void *buf, size_t len);
+
+flash_status_t flash_write_block(uint32_t addr, const void *buf, size_t len);
+
+#ifdef __cplusplus
+}
+#endif