drivers/flash: it51xxx: Add the M1K flash driver

The flash M1K driver supports read (up to 1K), write (1K), and
erase (4K) operations, which can be accessed via DLM.
Accessible flash regions include internal e-Flash or external SPI
flash via FSCE# or FSCE1#.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>

Author: GTLin08

drivers/flash/CMakeLists.txt

@@ -49,6 +49,7 @@ zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_CC13XX_CC26XX soc_flash_cc13xx_cc2
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_CC23X0 soc_flash_cc23x0.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_ESP32 flash_esp32.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_GECKO flash_gecko.c)
+zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_ITE_IT51XXX_M1K flash_ite_it51xxx_m1k.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_ITE_IT8XXX2 flash_ite_it8xxx2.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_LPC soc_flash_lpc.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_MAX32 flash_max32.c)

drivers/flash/Kconfig

@@ -176,6 +176,7 @@ source "drivers/flash/Kconfig.esp32"
 source "drivers/flash/Kconfig.gd32"
 source "drivers/flash/Kconfig.gecko"
 source "drivers/flash/Kconfig.ifx_cat1"
+source "drivers/flash/Kconfig.it51xxx_m1k"
 source "drivers/flash/Kconfig.it8xxx2"
 source "drivers/flash/Kconfig.lpc"
 source "drivers/flash/Kconfig.max32"

drivers/flash/Kconfig.it51xxx_m1k

@@ -0,0 +1,14 @@
+# Copyright (c) 2025 ITE Corporation. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+config SOC_FLASH_ITE_IT51XXX_M1K
+	bool "ITE IT51XXX manual flash 1k driver"
+	default y
+	depends on DT_HAS_ITE_IT51XXX_MANUAL_FLASH_1K_ENABLED
+	select FLASH_HAS_PAGE_LAYOUT
+	select FLASH_HAS_DRIVER_ENABLED
+	select PINCTRL
+	help
+	  The flash M1K driver supports read (up to 1K), write (1K), and erase (4K)
+	  operations. Accessible flash regions include internal e-Flash or external
+	  SPI flash via FSCE# or FSCE1#