Turris Omnia MCU driver

new file mode 100644
index 000000000000..ea1fd0117bb8
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/cznic,turris-omnia-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: CZ.NIC's Turris Omnia MCU
+
+maintainers:
+  - Marek Behún <[email protected]>
+
+description:
+  The MCU on Turris Omnia acts as a system controller providing additional
+  GPIOs, interrupts, watchdog, system power off and wakeup configuration.
+
+properties:
+  compatible:
+    const: cznic,turris-omnia-mcu
+
+  reg:
+    description: MCU I2C slave address
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interrupt-controller: true
+
+  '#interrupt-cells':
+    const: 2
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+  - gpio-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        system-controller@2a {
+            compatible = "cznic,turris-omnia-mcu";
+            reg = <0x2a>;
+
+            interrupt-parent = <&gpio1>;
+            interrupts = <11 IRQ_TYPE_NONE>;
+
+            gpio-controller;
+            #gpio-cells = <2>;
+
+            interrupt-controller;
+            #interrupt-cells = <2>;
+        };
+    };

index 2894f0777537..56cb540bb4ef 100644
@@ -2102,6 +2102,7 @@ W:	https://www.turris.cz/
 F:	Documentation/ABI/testing/debugfs-moxtet
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/ABI/testing/sysfs-firmware-turris-mox-rwtm
+F:	Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml
 F:	Documentation/devicetree/bindings/bus/moxtet.txt
 F:	Documentation/devicetree/bindings/firmware/cznic,turris-mox-rwtm.txt
 F:	Documentation/devicetree/bindings/gpio/gpio-moxtet.txt

new file mode 100644
index 000000000000..72cdf0cfce3e
@@ -0,0 +1,45 @@
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_features
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RO) Newer versions of the microcontroller firmware report the
+		features they support. These can be read from this file. If the
+		MCU firmware is too old, this file reads 0x0.
+
+		Format: 0x%x.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_version_hash_application
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RO) Contains the version hash (commit hash) of the application
+		part of the microcontroller firmware.
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/fw_version_hash_bootloader
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RO) Contains the version hash (commit hash) of the bootloader
+		part of the microcontroller firmware.
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/mcu_type
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RO) Contains the microcontroller type (STM32, GD32, MKL).
+
+		Format: %s.
+
+What:		/sys/bus/i2c/devices/<mcu_device>/reset_selector
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RO) Contains the selected factory reset level, determined by
+		how long the rear reset button was held by the user during board
+		reset.
+
+		Format: %i.

index 56cb540bb4ef..8dab94d51c47 100644
@@ -2100,6 +2100,7 @@ M:	Marek Behún <[email protected]>
 S:	Maintained
 W:	https://www.turris.cz/
 F:	Documentation/ABI/testing/debugfs-moxtet
+F:	Documentation/ABI/testing/sysfs-bus-i2c-devices-turris-omnia-mcu
 F:	Documentation/ABI/testing/sysfs-bus-moxtet-devices
 F:	Documentation/ABI/testing/sysfs-firmware-turris-mox-rwtm
 F:	Documentation/devicetree/bindings/arm/cznic,turris-omnia-mcu.yaml

@@ -2113,10 +2114,12 @@ F:	drivers/firmware/turris-mox-rwtm.c
 F:	drivers/gpio/gpio-moxtet.c
 F:	drivers/leds/leds-turris-omnia.c
 F:	drivers/mailbox/armada-37xx-rwtm-mailbox.c
+F:	drivers/platform/cznic/
 F:	drivers/watchdog/armada_37xx_wdt.c
 F:	include/dt-bindings/bus/moxtet.h
 F:	include/linux/armada-37xx-rwtm-mailbox.h
 F:	include/linux/moxtet.h
+F:	include/linux/turris-omnia-mcu-interface.h
 
 ARM/FARADAY FA526 PORT
 M:	Hans Ulli Kroll <[email protected]>

index 868b20361769..fef907a94001 100644
@@ -7,6 +7,8 @@ source "drivers/platform/goldfish/Kconfig"
 
 source "drivers/platform/chrome/Kconfig"
 
+source "drivers/platform/cznic/Kconfig"
+
 source "drivers/platform/mellanox/Kconfig"
 
 source "drivers/platform/olpc/Kconfig"

index 41640172975a..8bf189264374 100644
@@ -10,4 +10,5 @@ obj-$(CONFIG_MIPS)		+= mips/
 obj-$(CONFIG_OLPC_EC)		+= olpc/
 obj-$(CONFIG_GOLDFISH)		+= goldfish/
 obj-$(CONFIG_CHROME_PLATFORMS)	+= chrome/
+obj-$(CONFIG_CZNIC_PLATFORMS)	+= cznic/
 obj-$(CONFIG_SURFACE_PLATFORMS)	+= surface/

new file mode 100644
index 000000000000..f8560ff9c1af
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# For a description of the syntax of this configuration file,
+# see Documentation/kbuild/kconfig-language.rst.
+#
+
+menuconfig CZNIC_PLATFORMS
+	bool "Platform support for CZ.NIC's Turris hardware"
+	depends on MACH_ARMADA_38X || COMPILE_TEST
+	help
+	  Say Y here to be able to choose driver support for CZ.NIC's Turris
+	  devices. This option alone does not add any kernel code.
+
+if CZNIC_PLATFORMS
+
+config TURRIS_OMNIA_MCU
+	tristate "Turris Omnia MCU driver"
+	depends on MACH_ARMADA_38X || COMPILE_TEST
+	depends on I2C
+	help
+	  Say Y here to add support for the features implemented by the
+	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
+	  To compile this driver as a module, choose M here; the module will be
+	  called turris-omnia-mcu.
+
+endif # CZNIC_PLATFORMS

new file mode 100644
index 000000000000..4d0a9586538c
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
+turris-omnia-mcu-objs		:= turris-omnia-mcu-base.o

index 72cdf0cfce3e..e635ba45ef9a 100644
@@ -1,3 +1,19 @@
+What:		/sys/bus/i2c/devices/<mcu_device>/front_button_mode
+Date:		November 2023
+KernelVersion:	6.7
+Contact:	Marek Behún <[email protected]>
+Description:	(RW) The front button on the Turris Omnia router can be
+		configured either to change the intensity of all the LEDs on the
+		front panel, or to send the press event to the CPU as an
+		interrupt.
+
+		This file switches between these two modes:
+		- "mcu" makes the button press event be handled by the MCU to
+		  change the LEDs panel intensity.
+		- "cpu" makes the button press event be handled by the CPU.
+
+		Format: %s.
+
 What:		/sys/bus/i2c/devices/<mcu_device>/fw_features
 Date:		November 2023
 KernelVersion:	6.7

index f8560ff9c1af..3a8c3edcd7e6 100644
@@ -17,9 +17,24 @@ config TURRIS_OMNIA_MCU
 	tristate "Turris Omnia MCU driver"
 	depends on MACH_ARMADA_38X || COMPILE_TEST
 	depends on I2C
+	select GPIOLIB
+	select GPIOLIB_IRQCHIP
 	help
 	  Say Y here to add support for the features implemented by the
 	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
+	  The features include:
+	  - GPIO pins
+	    - to get front button press events (the front button can be
+	      configured either to generate press events to the CPU or to change
+	      front LEDs panel brightness)
+	    - to enable / disable USB port voltage regulators and to detect
+	      USB overcurrent
+	    - to detect MiniPCIe / mSATA card presence in MiniPCIe port 0
+	    - to configure resets of various peripherals on board revisions 32+
+	    - to enable / disable the VHV voltage regulator to the SOC in order
+	      to be able to program SOC's OTP on board revisions 32+
+	    - to get input from the LED output pins of the WAN ethernet PHY, LAN
+	      switch and MiniPCIe ports
 	  To compile this driver as a module, choose M here; the module will be
 	  called turris-omnia-mcu.
 

index 4d0a9586538c..a6177f5b4fff 100644
@@ -2,3 +2,4 @@
 
 obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
 turris-omnia-mcu-objs		:= turris-omnia-mcu-base.o
+turris-omnia-mcu-objs		+= turris-omnia-mcu-gpio.o

index e635ba45ef9a..a69172d5b998 100644
@@ -14,6 +14,22 @@ Description:	(RW) The front button on the Turris Omnia router can be
 
 		Format: %s.
 
+What:		/sys/bus/i2c/devices/<mcu_device>/front_button_poweron
+Date:		August 2023
+KernelVersion:	6.6
+Contact:	Marek Behún <[email protected]>
+Description:	(RW) Newer versions of the microcontroller firmware of the
+		Turris Omnia router support powering off the router into true
+		low power mode. The router can be powered on by pressing the
+		front button.
+
+		This file configures whether front button power on is enabled.
+
+		This file is present only if the power off feature is supported
+		by the firmware.
+
+		Format: %i.
+
 What:		/sys/bus/i2c/devices/<mcu_device>/fw_features
 Date:		November 2023
 KernelVersion:	6.7

index 3a8c3edcd7e6..0a752aa654fa 100644
@@ -19,10 +19,14 @@ config TURRIS_OMNIA_MCU
 	depends on I2C
 	select GPIOLIB
 	select GPIOLIB_IRQCHIP
+	select RTC_CLASS
 	help
 	  Say Y here to add support for the features implemented by the
 	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
 	  The features include:
+	  - board poweroff into true low power mode (with voltage regulators
+	    disabled) and the ability to configure wake up from this mode (via
+	    rtcwake)
 	  - GPIO pins
 	    - to get front button press events (the front button can be
 	      configured either to generate press events to the CPU or to change

index a6177f5b4fff..6f1470d1f673 100644
@@ -3,3 +3,4 @@
 obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
 turris-omnia-mcu-objs		:= turris-omnia-mcu-base.o
 turris-omnia-mcu-objs		+= turris-omnia-mcu-gpio.o
+turris-omnia-mcu-objs		+= turris-omnia-mcu-sys-off-wakeup.o

index 0a752aa654fa..e2649cdecc38 100644
@@ -20,6 +20,7 @@ config TURRIS_OMNIA_MCU
 	select GPIOLIB
 	select GPIOLIB_IRQCHIP
 	select RTC_CLASS
+	select WATCHDOG_CORE
 	help
 	  Say Y here to add support for the features implemented by the
 	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.

@@ -27,6 +28,7 @@ config TURRIS_OMNIA_MCU
 	  - board poweroff into true low power mode (with voltage regulators
 	    disabled) and the ability to configure wake up from this mode (via
 	    rtcwake)
+	  - MCU watchdog
 	  - GPIO pins
 	    - to get front button press events (the front button can be
 	      configured either to generate press events to the CPU or to change

index 6f1470d1f673..a43997a12d74 100644
@@ -4,3 +4,4 @@ obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
 turris-omnia-mcu-objs		:= turris-omnia-mcu-base.o
 turris-omnia-mcu-objs		+= turris-omnia-mcu-gpio.o
 turris-omnia-mcu-objs		+= turris-omnia-mcu-sys-off-wakeup.o
+turris-omnia-mcu-objs		+= turris-omnia-mcu-watchdog.o

index 2d8d319bec83..7682fda4000a 100644
@@ -218,7 +218,22 @@ i2c@0 {
 			#size-cells = <0>;
 			reg = <0>;
 
-			/* STM32F0 command interface at address 0x2a */
+			mcu: system-controller@2a {
+				compatible = "cznic,turris-omnia-mcu";
+				reg = <0x2a>;
+
+				pinctrl-names = "default";
+				pinctrl-0 = <&mcu_pins>;
+
+				interrupt-parent = <&gpio1>;
+				interrupts = <11 IRQ_TYPE_NONE>;
+
+				gpio-controller;
+				#gpio-cells = <2>;
+
+				interrupt-controller;
+				#interrupt-cells = <2>;
+			};
 
 			led-controller@2b {
 				compatible = "cznic,turris-omnia-leds";

@@ -503,6 +518,11 @@ fixed-link {
 };
 
 &pinctrl {
+	mcu_pins: mcu-pins {
+		marvell,pins = "mpp43";
+		marvell,function = "gpio";
+	};
+
 	pcawan_pins: pcawan-pins {
 		marvell,pins = "mpp46";
 		marvell,function = "gpio";

index 7682fda4000a..016adfa0b470 100644
@@ -112,6 +112,19 @@ sfp: sfp {
 		status = "disabled";
 	};
 
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		front-button {
+			label = "Front Button";
+			linux,code = <KEY_VENDOR>;
+			linux,can-disable;
+			gpios = <&mcu 12 GPIO_ACTIVE_HIGH>;
+			/* debouncing is done by the microcontroller */
+			debounce-interval = <0>;
+		};
+	};
+
 	sound {
 		compatible = "simple-audio-card";
 		simple-audio-card,name = "SPDIF";