[PATCH 0/4] mfd: Add support for the MCU in the UGREEN DH2300 NAS

[PATCH 0/4] mfd: Add support for the MCU in the UGREEN DH2300 NAS

[Alexey Charkov]

UGREEN DH2300 is a 2-bay SATA NAS based on the Rockchip RK3576 SoC. It
includes an embedded controller connected over I2C which won't let the
drives power up without its register being poked first, which precludes
the use of the device for its main purpose.

There is no public documentation or source code available, but apparently
the MCU is also responsible for a hardware watchdog function and some type
of wake functionality, so this series implements an MFD-regulator
separation right away to allow for adding these functions properly later
on.

For now though a single-bit write to the MCU seems to be sufficient to get
the drives to work with only a board DTS addition [1] - to be submitted
separately.

[1] https://github.com/flipperdevices/flipper-linux-kernel/blob/2c1c5ee609f6ed4c77e9e5428df91e98b3f50cce/arch/arm64/boot/dts/rockchip/rk3576-nasync-dh2300.dts

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
Alexey Charkov (4):
      dt-bindings: vendor-prefixes: Add Ugreen Group Limited
      dt-bindings: mfd: Add UGREEN NASync DH2300 MCU
      mfd: Add support for UGREEN NASync DH2300 MCU
      regulator: Add support for UGREEN NASync DH2300 MCU SATA power gate

 .../devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml | 62 +++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.yaml       |  2 +
 MAINTAINERS                                        |  7 ++
 drivers/mfd/Kconfig                                | 16 +++++
 drivers/mfd/Makefile                               |  1 +
 drivers/mfd/ugreen-dh2300-mcu.c                    | 60 ++++++++++++++++
 drivers/regulator/Kconfig                          | 12 ++++
 drivers/regulator/Makefile                         |  1 +
 drivers/regulator/ugreen-dh2300-mcu-regulator.c    | 80 ++++++++++++++++++++++
 9 files changed, 241 insertions(+)
---
base-commit: ec039126b7fac4e3af35ebccaa7c6f9b6875ba81
change-id: 20260612-dh2300-mcu-5354d1f5f11a

Best regards,
--  
Alexey Charkov <alchark@flipper.net>

[PATCH 1/4] dt-bindings: vendor-prefixes: Add Ugreen Group Limited

[Alexey Charkov]

Add Ugreen Group Limited, a consumer technology company producing a range
of smart charging, office audio and visual, and smart storage products.

Link: https://www.ugreen.com/
Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index dd94c50e97f9..274e52421a5b 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -1757,6 +1757,8 @@ patternProperties:
     description: Ufi Space Co., Ltd.
   "^ugoos,.*":
     description: Ugoos Industrial Co., Ltd.
+  "^ugreen,.*":
+    description: Ugreen Group Limited
   "^ultrapower,.*":
     description: Beijing Ultrapower Software Co., Ltd.
   "^uni-t,.*":

-- 
2.53.0

[PATCH 2/4] dt-bindings: mfd: Add UGREEN NASync DH2300 MCU

[Alexey Charkov]

Document the UGREEN NASync DH2300 embedded controller (HC32F005 MCU),
which is responsible for gating the SATA drive-bay power rail and
providing a hardware watchdog.

This is based on disassebly of a GPL binary from vendor firmware for which
no source code could be found, so parts of it can be inaccurate. Only
the power gating function is confirmed.

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 .../devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml | 62 ++++++++++++++++++++++
 MAINTAINERS                                        |  5 ++
 2 files changed, 67 insertions(+)

diff --git a/Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml b/Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml
new file mode 100644
index 000000000000..847970c609cd
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/ugreen,dh2300-mcu.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: UGREEN NASync DH2300 embedded controller
+
+maintainers:
+  - Alexey Charkov <alchark@flipper.net>
+
+description:
+  The UGREEN NASync DH2300 NAS carries a HC32F005 microcontroller on I2C that
+  acts as a board embedded controller. It gates power to the SATA drive bays
+  through an internal register and apparently also serves as a watchdog
+  (unconfirmed, as vendor kernel sources are unavailable, works without it)
+
+properties:
+  compatible:
+    const: ugreen,dh2300-mcu
+
+  reg:
+    maxItems: 1
+
+  regulator:
+    type: object
+    $ref: /schemas/regulator/regulator.yaml#
+    unevaluatedProperties: false
+    description:
+      The SATA drive-bay power gate controlled by the MCU.
+
+  watchdog-gpios:
+    description:
+      Optional GPIO line used to ping the hardware watchdog function of the MCU
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/pinctrl/rockchip.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        embedded-controller@4c {
+            compatible = "ugreen,dh2300-mcu";
+            reg = <0x4c>;
+            watchdog-gpios = <&gpio0 RK_PA0 GPIO_ACTIVE_LOW>;
+
+            sata_power: regulator {
+                regulator-name = "sata-power";
+                vin-supply = <&vcc12v_dcin>;
+            };
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index f1caa6e5198b..ca27df7cd684 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27633,6 +27633,11 @@ L:	linux-input@vger.kernel.org
 S:	Maintained
 F:	drivers/hid/hid-udraw-ps3.c
 
+UGREEN DH2300 MCU MFD DRIVER
+M:	Alexey Charkov <alchark@flipper.net>
+S:	Maintained
+F:	Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml
+
 UHID USERSPACE HID IO DRIVER
 M:	David Rheinsberg <david@readahead.eu>
 L:	linux-input@vger.kernel.org

-- 
2.53.0

[PATCH 3/4] mfd: Add support for UGREEN NASync DH2300 MCU

[Alexey Charkov]

Add a driver for the HC32F005 MCU used as an embedded controller on the
UGREEN NASync DH2300 NAS.

This part provides the shared I2C regmap to be used by function-specific
sub-devices, and instantiates the SATA drive-bay power gate regulator.
Implemented as an MFD to allow for other functions of the MCU to be added
later: vendor binaries imply that it also provides a hardware watchdog
and somehow serves as a wake source, but so far only the SATA power gating
function has been confirmed in absence of documentation and sources for the
vendor firmware.

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 MAINTAINERS                     |  1 +
 drivers/mfd/Kconfig             | 16 +++++++++++
 drivers/mfd/Makefile            |  1 +
 drivers/mfd/ugreen-dh2300-mcu.c | 60 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 78 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index ca27df7cd684..9578a06fe651 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27637,6 +27637,7 @@ UGREEN DH2300 MCU MFD DRIVER
 M:	Alexey Charkov <alchark@flipper.net>
 S:	Maintained
 F:	Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml
+F:	drivers/mfd/ugreen-dh2300-mcu.c
 
 UHID USERSPACE HID IO DRIVER
 M:	David Rheinsberg <david@readahead.eu>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 763ce6a34782..5a2ad75bd9c9 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1947,6 +1947,22 @@ config MFD_TPS6594_SPI
 	  This driver can also be built as a module.  If so, the module
 	  will be called tps6594-spi.
 
+config MFD_UGREEN_DH2300_MCU
+	tristate "UGREEN NASync DH2300 embedded controller"
+	depends on I2C
+	depends on OF
+	select MFD_CORE
+	select REGMAP_I2C
+	help
+	  Say yes here to enable support for the HC32F005 microcontroller found
+	  on the UGREEN NASync DH2300 NAS, where it acts as a board embedded
+	  controller. This core driver sets up the shared register map and
+	  instantiates the function sub-devices (the SATA drive-bay power
+	  regulator).
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ugreen-dh2300-mcu.
+
 config TWL4030_CORE
 	bool "TI TWL4030/TWL5030/TWL6030/TPS659x0 Support"
 	depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index dd4bb7e77c33..6247239bcfe1 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_MFD_TPS65912_SPI)  += tps65912-spi.o
 obj-$(CONFIG_MFD_TPS6594)	+= tps6594-core.o
 obj-$(CONFIG_MFD_TPS6594_I2C)	+= tps6594-i2c.o
 obj-$(CONFIG_MFD_TPS6594_SPI)	+= tps6594-spi.o
+obj-$(CONFIG_MFD_UGREEN_DH2300_MCU)	+= ugreen-dh2300-mcu.o
 obj-$(CONFIG_MENELAUS)		+= menelaus.o
 
 obj-$(CONFIG_TWL4030_CORE)	+= twl-core.o twl4030-irq.o twl6030-irq.o
diff --git a/drivers/mfd/ugreen-dh2300-mcu.c b/drivers/mfd/ugreen-dh2300-mcu.c
new file mode 100644
index 000000000000..5184b0c98759
--- /dev/null
+++ b/drivers/mfd/ugreen-dh2300-mcu.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Core driver for the UGREEN NASync DH2300 embedded controller (HC32F005 MCU).
+ *
+ * The microcontroller sits on I2C and exposes an 8-bit register map. It is a
+ * multi-function device: SATA drive-bay power gate, hardware watchdog and
+ * possibly other functions
+ */
+
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#define UGREEN_DH2300_MCU_REG_MAX	0x94
+
+static const struct regmap_config ugreen_dh2300_mcu_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = UGREEN_DH2300_MCU_REG_MAX,
+};
+
+static const struct mfd_cell ugreen_dh2300_mcu_cells[] = {
+	{ .name = "ugreen-dh2300-mcu-regulator" },
+};
+
+static int ugreen_dh2300_mcu_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+
+	regmap = devm_regmap_init_i2c(client, &ugreen_dh2300_mcu_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "failed to initialise regmap\n");
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO,
+				    ugreen_dh2300_mcu_cells,
+				    ARRAY_SIZE(ugreen_dh2300_mcu_cells),
+				    NULL, 0, NULL);
+}
+
+static const struct of_device_id ugreen_dh2300_mcu_of_match[] = {
+	{ .compatible = "ugreen,dh2300-mcu" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ugreen_dh2300_mcu_of_match);
+
+static struct i2c_driver ugreen_dh2300_mcu_driver = {
+	.driver = {
+		.name = "ugreen-dh2300-mcu",
+		.of_match_table = ugreen_dh2300_mcu_of_match,
+	},
+	.probe = ugreen_dh2300_mcu_probe,
+};
+module_i2c_driver(ugreen_dh2300_mcu_driver);
+
+MODULE_DESCRIPTION("UGREEN NASync DH2300 embedded controller core driver");
+MODULE_LICENSE("GPL");

-- 
2.53.0

[PATCH 4/4] regulator: Add support for UGREEN NASync DH2300 MCU SATA power gate

[Alexey Charkov]

Add a driver for the SATA drive-bay power gate function of the UGREEN
NASync DH2300 embedded controller (HC32F005 MCU).

This is a simple on/off regulator, controlled by bit 0 of register 0x41,
with inverted polarity (0 = enabled, 1 = disabled). Boot-time default is
disabled, so this driver is required to use the NAS functionality.

Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 MAINTAINERS                                     |  1 +
 drivers/regulator/Kconfig                       | 12 ++++
 drivers/regulator/Makefile                      |  1 +
 drivers/regulator/ugreen-dh2300-mcu-regulator.c | 80 +++++++++++++++++++++++++
 4 files changed, 94 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 9578a06fe651..2fc84be86e46 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -27638,6 +27638,7 @@ M:	Alexey Charkov <alchark@flipper.net>
 S:	Maintained
 F:	Documentation/devicetree/bindings/mfd/ugreen,dh2300-mcu.yaml
 F:	drivers/mfd/ugreen-dh2300-mcu.c
+F:	drivers/regulator/ugreen-dh2300-mcu-regulator.c
 
 UHID USERSPACE HID IO DRIVER
 M:	David Rheinsberg <david@readahead.eu>
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index a54a549196fe..e692ff864806 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1812,6 +1812,18 @@ config REGULATOR_TWL4030
 	  This driver supports the voltage regulators provided by
 	  this family of companion chips.
 
+config REGULATOR_UGREEN_DH2300_MCU
+	tristate "UGREEN NASync DH2300 MCU SATA power regulator"
+	depends on MFD_UGREEN_DH2300_MCU
+	help
+	  Say yes here to enable support for the SATA drive-bay power gate of
+	  the UGREEN NASync DH2300 embedded controller. The regulator is a
+	  sub-device of the ugreen-dh2300-mcu MFD core and is normally consumed
+	  by the SATA controllers via their target-supply.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called ugreen-dh2300-mcu-regulator.
+
 config REGULATOR_UNIPHIER
 	tristate "UniPhier regulator driver"
 	depends on ARCH_UNIPHIER || COMPILE_TEST
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 134eee274dbf..44956d795923 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -206,6 +206,7 @@ obj-$(CONFIG_REGULATOR_TPS6594) += tps6594-regulator.o
 obj-$(CONFIG_REGULATOR_TPS65132) += tps65132-regulator.o
 obj-$(CONFIG_REGULATOR_TPS68470) += tps68470-regulator.o
 obj-$(CONFIG_REGULATOR_TWL4030) += twl-regulator.o twl6030-regulator.o
+obj-$(CONFIG_REGULATOR_UGREEN_DH2300_MCU) += ugreen-dh2300-mcu-regulator.o
 obj-$(CONFIG_REGULATOR_UNIPHIER) += uniphier-regulator.o
 obj-$(CONFIG_REGULATOR_RZG2L_VBCTRL) += renesas-usb-vbus-regulator.o
 obj-$(CONFIG_REGULATOR_VCTRL) += vctrl-regulator.o
diff --git a/drivers/regulator/ugreen-dh2300-mcu-regulator.c b/drivers/regulator/ugreen-dh2300-mcu-regulator.c
new file mode 100644
index 000000000000..69fda90f7ace
--- /dev/null
+++ b/drivers/regulator/ugreen-dh2300-mcu-regulator.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SATA drive-bay power gate for the UGREEN NASync DH2300 embedded controller
+ * (HC32F005 MCU).
+ *
+ * The microcontroller gates the SATA bay power rail through register 0x41.
+ * The polarity is inverted: writing 0 enables the rail, writing 1 disables it
+ * (the controller latches "off" out of reset).
+ */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define UGREEN_DH2300_MCU_REG_SATA_POWER	0x41
+
+static const struct regulator_ops ugreen_dh2300_sata_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+};
+
+static const struct regulator_desc ugreen_dh2300_sata_desc = {
+	.name = "sata-power",
+	.enable_is_inverted = true,
+	.enable_mask = 0x01,
+	.enable_reg = UGREEN_DH2300_MCU_REG_SATA_POWER,
+	.supply_name = "vin",
+	.ops = &ugreen_dh2300_sata_ops,
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+};
+
+static int ugreen_dh2300_mcu_regulator_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct regulator_config config = { };
+	struct regulator_dev *rdev;
+	struct device_node *np;
+
+	np = of_get_child_by_name(dev->parent->of_node, "regulator");
+	if (!np)
+		return dev_err_probe(dev, -ENODEV,
+				     "missing regulator child node\n");
+
+	config.dev = dev;
+	config.of_node = np;
+	config.regmap = dev_get_regmap(dev->parent, NULL);
+	if (!config.regmap) {
+		of_node_put(np);
+		return dev_err_probe(dev, -ENODEV,
+				     "no regmap available from parent\n");
+	}
+
+	config.init_data = of_get_regulator_init_data(dev, np,
+						      &ugreen_dh2300_sata_desc);
+
+	rdev = devm_regulator_register(dev, &ugreen_dh2300_sata_desc, &config);
+	of_node_put(np);
+	if (IS_ERR(rdev))
+		return dev_err_probe(dev, PTR_ERR(rdev),
+				     "failed to register regulator\n");
+
+	return 0;
+}
+
+static struct platform_driver ugreen_dh2300_mcu_regulator_driver = {
+	.driver = {
+		.name = "ugreen-dh2300-mcu-regulator",
+	},
+	.probe = ugreen_dh2300_mcu_regulator_probe,
+};
+module_platform_driver(ugreen_dh2300_mcu_regulator_driver);
+
+MODULE_DESCRIPTION("UGREEN NASync DH2300 MCU SATA power regulator");
+MODULE_LICENSE("GPL");

-- 
2.53.0

Re: [PATCH 4/4] regulator: Add support for UGREEN NASync DH2300 MCU SATA power gate

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The platform driver lacks a MODULE_ALIAS() declaration, which prevents automatic module loading.
--

commit 64ccd270dc21c4fa03f9ebc2bb443018b396eeab
Author: Alexey Charkov <alchark@flipper.net>

regulator: Add support for UGREEN NASync DH2300 MCU SATA power gate

This commit adds a driver for the SATA drive-bay power gate function of the
UGREEN NASync DH2300 embedded controller. It acts as a simple on/off regulator
controlled by register 0x41.

> diff --git a/drivers/regulator/ugreen-dh2300-mcu-regulator.c b/drivers/regulator/ugreen-dh2300-mcu-regulator.c
> new file mode 100644
> index 0000000000000..69fda90f7ace6
> --- /dev/null
> +++ b/drivers/regulator/ugreen-dh2300-mcu-regulator.c

[ ... ]

> +static struct platform_driver ugreen_dh2300_mcu_regulator_driver = {
> +	.driver = {
> +		.name = "ugreen-dh2300-mcu-regulator",
> +	},
> +	.probe = ugreen_dh2300_mcu_regulator_probe,
> +};
> +module_platform_driver(ugreen_dh2300_mcu_regulator_driver);
> +
> +MODULE_DESCRIPTION("UGREEN NASync DH2300 MCU SATA power regulator");
> +MODULE_LICENSE("GPL");

[Severity: Medium]
Will ugreen_dh2300_mcu_regulator_driver load automatically when built as a
module?

This driver lacks an id_table, of_match_table, or a MODULE_ALIAS declaration.
When the MFD core registers the sub-device, the platform bus emits a uevent
with MODALIAS=platform:ugreen-dh2300-mcu-regulator.

Without the alias mapping, udev/modprobe might fail to automatically load
the driver on boot, leaving the SATA drives unpowered unless the module
is manually loaded.

Would it make sense to add MODULE_ALIAS("platform:ugreen-dh2300-mcu-regulator")?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260612-dh2300-mcu-v1-0-ab8db1617bc0@flipper.net?part=4

Re: [PATCH 4/4] regulator: Add support for UGREEN NASync DH2300 MCU SATA power gate

[Mark Brown]

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On Fri, Jun 12, 2026 at 07:34:17PM +0400, Alexey Charkov wrote:

> +static int ugreen_dh2300_mcu_regulator_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct regulator_config config = { };
> +	struct regulator_dev *rdev;
> +	struct device_node *np;
> +
> +	np = of_get_child_by_name(dev->parent->of_node, "regulator");
> +	if (!np)
> +		return dev_err_probe(dev, -ENODEV,
> +				     "missing regulator child node\n");

You should just be able to configured this in the regulator_desc rather
than describe it.

> +	config.init_data = of_get_regulator_init_data(dev, np,
> +						      &ugreen_dh2300_sata_desc);
> +

Similarly here, there should be no need for this open coding.

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Re: [PATCH 1/4] dt-bindings: vendor-prefixes: Add Ugreen Group Limited

[Conor Dooley]

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Acked-by: Conor Dooley <conor.dooley@microchip.com>
pw-bot: not-applicable

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