[PATCH v9 0/6] Add VIM4 MCU/FAN support

[PATCH v9 0/6] Add VIM4 MCU/FAN support

[Ronald Claveau via B4 Relay]

The Khadas VIM4 board features a different MCU variant compared to
previous VIM boards.
While it shares the same I2C-based communication model,
it differs in some ways:

  - A distinct register map with its own volatile/writeable register set
  - A fan control with 0–100 levels instead of the 0–3 levels previously
  - A fan power supply gated through a regulator

This series adds support for this new variant by:

  1. Refactoring the khadas-mcu MFD driver to use per-variant data
     structures (regmap config, cells, fan platform data),
     and adding the khadas,vim4-mcu compatible string.

  2. Extending the fan thermal driver to retrieve the fan register
     and maximum level from platform_data,
     and to optionally manage a power regulator for the fan supply.

  3. Adding the corresponding DTS node for the VIM4, wiring the MCU to
     the I2C AO_A bus and exposing it as a thermal cooling device.

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
Changes in v9:
- Rebased on next-20260731 (patches 1/8, 2/8 and 6/8 already applied, dropped from this series).
- PATCH 1: Add levels table and nlevels in khadas_mcu_fan_pdata struct.
- PATCH 2: Use MFD_CELL_* macros instead of open-coding mfd_cell.
- PATCH 3: Provide levels table and nlevels to platform data.
           Check match_data before the switch.
- PATCH 4: Use levels[] and nlevels from platform data. VIM4 levels is (0, 30, 40, 55, 75, 100).
- Link to v8: https://lore.kernel.org/r/20260702-add-mcu-fan-khadas-vim4-v8-0-244feee91a36@aliel.fr

Changes in v8:
- PATCH 4: Define constant for fan max level, remove extra space for unnecessary alignment.
           Thanks to Lee's review.
- Link to v7: https://lore.kernel.org/r/20260603-add-mcu-fan-khadas-vim4-v7-0-594ba8a965d8@aliel.fr

Changes in v7:
- PATCH 3-4: Simplify the per-variant handling by using local variables in khadas_mcu_probe()
             instead of introducing a dedicated data structure. Thanks to Lee's review.
- Link to v6: https://lore.kernel.org/r/20260516-add-mcu-fan-khadas-vim4-v6-0-cccc9b61f465@aliel.fr

Changes in v6:
- PATCH 4: Address Lee's review comments:
  - Use an enum to discriminate between MCU types instead of passing
    MFD data through the DT match table
  - Fix error code from -EINVAL to -ENODEV when no MCU type is matched
  - Make khadas_mcu_fan_cells and khadas_mcu_cells const
  - Use dev_err_probe() for regmap initialization error
  - Document fan speed levels for max_level
- Link to v5: https://lore.kernel.org/r/20260424-add-mcu-fan-khadas-vim4-v5-0-afcfa7157b23@aliel.fr

Changes in v5:
- PATCH 5: Replace devm_regulator_get_optional() with devm_regulator_get()
           to simplify error handling and remove NULL checks, also
           ordering as reverse christmas according to Neil's feedback.
- Link to v4: https://lore.kernel.org/r/20260421-add-mcu-fan-khadas-vim4-v4-0-447114a28f2d@aliel.fr

Changes in v4:
- PATCH 1: limit fan-supply property by compatible according to Conor's feedback.
- Link to v3: https://lore.kernel.org/r/20260417-add-mcu-fan-khadas-vim4-v3-0-a6a7f570b11b@aliel.fr

Changes in v3:
- PATCH 1: adding comment on vim4 compatible saying it is not discoverable,
           thanks to Rob's and Neil's feedback.
- Link to v2: https://lore.kernel.org/r/20260403-add-mcu-fan-khadas-vim4-v2-0-70536b22439a@aliel.fr

Changes in v2:
- PATCH 5: Add regulator_disable on suspend thanks to Neil's feedback.
- Link to v1: https://lore.kernel.org/r/20260402-add-mcu-fan-khadas-vim4-v1-0-2b12eb4ac7b0@aliel.fr

---
Ronald Claveau (6):
      mfd: khadas-mcu: Add per-variant configuration infrastructure and VIM4 support
      mfd: khadas-mcu: Use MFD_CELL_* macros for cell declarations
      mfd: khadas-mcu: Add support for VIM4 MCU variant
      thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support
      arm64: dts: amlogic: t7: Add i2c controller node
      arm64: dts: amlogic: t7: khadas-vim4: Add i2c MCU fan node

 .../dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts  |  13 +++
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi        |  10 ++
 drivers/mfd/khadas-mcu.c                           | 126 ++++++++++++++++++---
 drivers/thermal/khadas_mcu_fan.c                   |  58 +++++++---
 include/linux/mfd/khadas-mcu.h                     |  24 ++++
 5 files changed, 197 insertions(+), 34 deletions(-)
---
base-commit: 9dba66b6217aacb924d997de3866e7e4c0dcf952
change-id: 20260402-add-mcu-fan-khadas-vim4-ac1cbe553c9b

Best regards,
-- 
Ronald Claveau <linux-kernel-dev@aliel.fr>

[PATCH v9 1/6] mfd: khadas-mcu: Add per-variant configuration infrastructure and VIM4 support

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Some values change per variant, add the structure to manage it.

Add an enum khadas_mcu_type used as value to match.

Also introduce khadas_mcu_fan_pdata to pass fan register address, a
table named levels to get fan-supported levels on the MCU, and the number
of levels to the fan sub-driver, removing the hardcoded constants.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 include/linux/mfd/khadas-mcu.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/include/linux/mfd/khadas-mcu.h b/include/linux/mfd/khadas-mcu.h
index a99ba2ed0e4e0..e4044c251b97e 100644
--- a/include/linux/mfd/khadas-mcu.h
+++ b/include/linux/mfd/khadas-mcu.h
@@ -70,6 +70,13 @@
 #define KHADAS_MCU_WOL_INIT_START_REG		0x87 /* WO */
 #define KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG	0x88 /* WO */
 
+/* VIM4 specific registers */
+#define KHADAS_MCU_VIM4_REST_CONF_REG		0x2c /* WO - reset EEPROM */
+#define KHADAS_MCU_VIM4_LED_ON_RAM_REG		0x89 /* WO - LED volatile */
+#define KHADAS_MCU_VIM4_FAN_CTRL_REG		0x8a /* WO */
+#define KHADAS_MCU_VIM4_WDT_EN_REG		0x8b /* WO */
+#define KHADAS_MCU_VIM4_SYS_RST_REG		0x91 /* WO */
+
 enum {
 	KHADAS_BOARD_VIM1 = 0x1,
 	KHADAS_BOARD_VIM2,
@@ -88,4 +95,21 @@ struct khadas_mcu {
 	struct regmap *regmap;
 };
 
+/**
+ * struct khadas_mcu_fan_pdata - fan sub-driver configuration
+ * @fan_reg: register address to write the fan level
+ * @levels: table mapping logical cooling-device states to raw fan levels
+ * @nlevels: number of entries in @levels
+ */
+struct khadas_mcu_fan_pdata {
+	unsigned int fan_reg;
+	const unsigned int *levels;
+	unsigned int nlevels;
+};
+
+enum khadas_mcu_type {
+	KHADAS_MCU_GENERIC, /* VIM1/2/3, Edge, Edge-V */
+	KHADAS_MCU_VIM4,
+};
+
 #endif /* MFD_KHADAS_MCU_H */

-- 
2.49.0

[PATCH v9 2/6] mfd: khadas-mcu: Use MFD_CELL_* macros for cell declarations

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Convert khadas_mcu_fan_cells[] and khadas_mcu_cells[] to use the
MFD_CELL_NAME() helper macro instead of open-coding the struct
mfd_cell initialisers. While at it, make both arrays const since
they are never modified after initialisation.

This is a pure cleanup with no functional change, done in
preparation for a subsequent patch which will need to attach
platform_data to the fan cell.

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 drivers/mfd/khadas-mcu.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/khadas-mcu.c b/drivers/mfd/khadas-mcu.c
index ba981a7886921..0e74efe14f367 100644
--- a/drivers/mfd/khadas-mcu.c
+++ b/drivers/mfd/khadas-mcu.c
@@ -75,13 +75,13 @@ static const struct regmap_config khadas_mcu_regmap_config = {
 	.cache_type	= REGCACHE_MAPLE,
 };
 
-static struct mfd_cell khadas_mcu_fan_cells[] = {
+static const struct mfd_cell khadas_mcu_fan_cells[] = {
 	/* VIM1/2 Rev13+ and VIM3 only */
-	{ .name = "khadas-mcu-fan-ctrl", },
+	MFD_CELL_NAME("khadas-mcu-fan-ctrl"),
 };
 
-static struct mfd_cell khadas_mcu_cells[] = {
-	{ .name = "khadas-mcu-user-mem", },
+static const struct mfd_cell khadas_mcu_cells[] = {
+	MFD_CELL_NAME("khadas-mcu-user-mem"),
 };
 
 static int khadas_mcu_probe(struct i2c_client *client)

-- 
2.49.0

[PATCH v9 3/6] mfd: khadas-mcu: Add support for VIM4 MCU variant

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Refactor probe() to use per-variant values
instead of hardcoded globals.

Add dedicated regmap configuration for the VIM4 MCU,
with its own volatile/writeable registers.

Introduce struct khadas_mcu_fan_pdata to pass the fan
control register and duty-cycle levels per variant.
VIM4 uses a different register and level set (0-100)
 declared as a list (0, 30, 40, 55, 75, 100) compared
 to previous boards (0-3).

Add a new compatible string "khadas,vim4-mcu".

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 drivers/mfd/khadas-mcu.c | 120 +++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 106 insertions(+), 14 deletions(-)

diff --git a/drivers/mfd/khadas-mcu.c b/drivers/mfd/khadas-mcu.c
index 0e74efe14f367..4cb305ac915e1 100644
--- a/drivers/mfd/khadas-mcu.c
+++ b/drivers/mfd/khadas-mcu.c
@@ -75,47 +75,138 @@ static const struct regmap_config khadas_mcu_regmap_config = {
 	.cache_type	= REGCACHE_MAPLE,
 };
 
+static const unsigned int khadas_mcu_fan_levels[] = {
+	0, 1, 2, 3,
+};
+
+static const struct khadas_mcu_fan_pdata khadas_mcu_fan_pdata = {
+	.fan_reg	= KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
+	.levels		= khadas_mcu_fan_levels,
+	.nlevels	= ARRAY_SIZE(khadas_mcu_fan_levels),
+};
+
 static const struct mfd_cell khadas_mcu_fan_cells[] = {
 	/* VIM1/2 Rev13+ and VIM3 only */
-	MFD_CELL_NAME("khadas-mcu-fan-ctrl"),
+	MFD_CELL_BASIC("khadas-mcu-fan-ctrl", NULL, &khadas_mcu_fan_pdata,
+		       sizeof(khadas_mcu_fan_pdata), 0),
 };
 
 static const struct mfd_cell khadas_mcu_cells[] = {
 	MFD_CELL_NAME("khadas-mcu-user-mem"),
 };
 
+static bool khadas_mcu_vim4_reg_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case KHADAS_MCU_PWR_OFF_CMD_REG:
+	case KHADAS_MCU_VIM4_REST_CONF_REG:
+	case KHADAS_MCU_WOL_INIT_START_REG:
+	case KHADAS_MCU_VIM4_LED_ON_RAM_REG:
+	case KHADAS_MCU_VIM4_FAN_CTRL_REG:
+	case KHADAS_MCU_VIM4_WDT_EN_REG:
+	case KHADAS_MCU_VIM4_SYS_RST_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool khadas_mcu_vim4_reg_writeable(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case KHADAS_MCU_VERSION_0_REG:
+	case KHADAS_MCU_VERSION_1_REG:
+	case KHADAS_MCU_SHUTDOWN_NORMAL_STATUS_REG:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static const struct regmap_config khadas_mcu_vim4_regmap_config = {
+	.reg_bits	= 8,
+	.reg_stride	= 1,
+	.val_bits	= 8,
+	.max_register	= KHADAS_MCU_VIM4_SYS_RST_REG,
+	.volatile_reg	= khadas_mcu_vim4_reg_volatile,
+	.writeable_reg	= khadas_mcu_vim4_reg_writeable,
+	.cache_type	= REGCACHE_MAPLE,
+};
+
+static const unsigned int khadas_mcu_vim4_fan_levels[] = {
+	0, 30, 40, 55, 75, 100,
+};
+
+static const struct khadas_mcu_fan_pdata khadas_mcu_vim4_fan_pdata = {
+	.fan_reg	= KHADAS_MCU_VIM4_FAN_CTRL_REG,
+	.levels		= khadas_mcu_vim4_fan_levels,
+	.nlevels	= ARRAY_SIZE(khadas_mcu_vim4_fan_levels),
+};
+
+static const struct mfd_cell khadas_mcu_vim4_fan_cells[] = {
+	MFD_CELL_BASIC("khadas-mcu-fan-ctrl", NULL, &khadas_mcu_vim4_fan_pdata,
+		       sizeof(khadas_mcu_vim4_fan_pdata), 0),
+};
+
 static int khadas_mcu_probe(struct i2c_client *client)
 {
+	const struct mfd_cell *cells, *fan_cells;
+	const struct regmap_config *regmap_cfg;
 	struct device *dev = &client->dev;
+	int ncells, nfan_cells, ret;
 	struct khadas_mcu *ddata;
-	int ret;
+	const void *match;
 
 	ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
 	if (!ddata)
 		return -ENOMEM;
 
+	match = i2c_get_match_data(client);
+	if (!match)
+		return -ENODEV;
+
+	switch ((uintptr_t)match) {
+	case KHADAS_MCU_GENERIC:
+		regmap_cfg	= &khadas_mcu_regmap_config;
+		cells		= khadas_mcu_cells;
+		ncells		= ARRAY_SIZE(khadas_mcu_cells);
+		fan_cells	= khadas_mcu_fan_cells;
+		nfan_cells	= ARRAY_SIZE(khadas_mcu_fan_cells);
+		break;
+	case KHADAS_MCU_VIM4:
+		regmap_cfg	= &khadas_mcu_vim4_regmap_config;
+		cells		= NULL;
+		ncells		= 0;
+		fan_cells	= khadas_mcu_vim4_fan_cells;
+		nfan_cells	= ARRAY_SIZE(khadas_mcu_vim4_fan_cells);
+		break;
+	default:
+		return -ENODEV;
+	}
+
 	i2c_set_clientdata(client, ddata);
 
 	ddata->dev = dev;
 
-	ddata->regmap = devm_regmap_init_i2c(client, &khadas_mcu_regmap_config);
+	ddata->regmap = devm_regmap_init_i2c(client, regmap_cfg);
 	if (IS_ERR(ddata->regmap)) {
 		ret = PTR_ERR(ddata->regmap);
-		dev_err(dev, "Failed to allocate register map: %d\n", ret);
-		return ret;
+		return dev_err_probe(dev, ret, "Failed to allocate register map\n");
 	}
 
-	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
-				   khadas_mcu_cells,
-				   ARRAY_SIZE(khadas_mcu_cells),
-				   NULL, 0, NULL);
-	if (ret)
-		return ret;
+	if (cells && ncells) {
+		ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+					   cells,
+					   ncells,
+					   NULL, 0, NULL);
+		if (ret)
+			return ret;
+	}
 
 	if (of_property_present(dev->of_node, "#cooling-cells"))
 		return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
-					    khadas_mcu_fan_cells,
-					    ARRAY_SIZE(khadas_mcu_fan_cells),
+					    fan_cells,
+					    nfan_cells,
 					    NULL, 0, NULL);
 
 	return 0;
@@ -123,7 +214,8 @@ static int khadas_mcu_probe(struct i2c_client *client)
 
 #ifdef CONFIG_OF
 static const struct of_device_id khadas_mcu_of_match[] = {
-	{ .compatible = "khadas,mcu", },
+	{ .compatible = "khadas,mcu", .data = (void *)KHADAS_MCU_GENERIC },
+	{ .compatible = "khadas,vim4-mcu", .data = (void *)KHADAS_MCU_VIM4 },
 	{},
 };
 MODULE_DEVICE_TABLE(of, khadas_mcu_of_match);

-- 
2.49.0

[PATCH v9 4/6] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Replace the hardcoded MAX_LEVEL constant and fan register
with values read from platform_data (fan_reg, levels[] and nlevels),
as new MCUs need different values.

The cooling device's state is stored as an index into levels[],
and khadas_mcu_fan_set_level() writes levels[state] to fan_reg,
rather than writing the raw state value as before.

Optionally acquire and enable a "fan" regulator supply
at probe time and on resume,
so boards that gate fan power through a regulator are handled.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 drivers/thermal/khadas_mcu_fan.c | 58 ++++++++++++++++++++++++++++------------
 1 file changed, 41 insertions(+), 17 deletions(-)

diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
index 21b3d0a71bd0d..c7f74394b823f 100644
--- a/drivers/thermal/khadas_mcu_fan.c
+++ b/drivers/thermal/khadas_mcu_fan.c
@@ -13,34 +13,30 @@
 #include <linux/regmap.h>
 #include <linux/sysfs.h>
 #include <linux/thermal.h>
-
-#define MAX_LEVEL 3
+#include <linux/regulator/consumer.h>
 
 struct khadas_mcu_fan_ctx {
 	struct khadas_mcu *mcu;
+	unsigned int fan_reg;
 	unsigned int level;
+	const unsigned int *levels;
+	unsigned int nlevels;
 	struct thermal_cooling_device *cdev;
+	struct regulator *power;
 };
 
 static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
 				    unsigned int level)
 {
-	int ret;
-
-	ret = regmap_write(ctx->mcu->regmap, KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
-			   level);
-	if (ret)
-		return ret;
-
-	ctx->level = level;
-
-	return 0;
+	return regmap_write(ctx->mcu->regmap, ctx->fan_reg, level);
 }
 
 static int khadas_mcu_fan_get_max_state(struct thermal_cooling_device *cdev,
 					unsigned long *state)
 {
-	*state = MAX_LEVEL;
+	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
+
+	*state = ctx->nlevels - 1;
 
 	return 0;
 }
@@ -60,14 +56,21 @@ khadas_mcu_fan_set_cur_state(struct thermal_cooling_device *cdev,
 			     unsigned long state)
 {
 	struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
+	int ret;
 
-	if (state > MAX_LEVEL)
+	if (state >= ctx->nlevels)
 		return -EINVAL;
 
 	if (state == ctx->level)
 		return 0;
 
-	return khadas_mcu_fan_set_level(ctx, state);
+	ret = khadas_mcu_fan_set_level(ctx, ctx->levels[state]);
+	if (ret)
+		return ret;
+
+	ctx->level = state;
+
+	return 0;
 }
 
 static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
@@ -78,6 +81,7 @@ static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
 
 static int khadas_mcu_fan_probe(struct platform_device *pdev)
 {
+	const struct khadas_mcu_fan_pdata *pdata = dev_get_platdata(&pdev->dev);
 	struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
 	struct thermal_cooling_device *cdev;
 	struct device *dev = &pdev->dev;
@@ -87,7 +91,22 @@ static int khadas_mcu_fan_probe(struct platform_device *pdev)
 	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
 	if (!ctx)
 		return -ENOMEM;
+
 	ctx->mcu = mcu;
+	ctx->fan_reg = pdata->fan_reg;
+	ctx->levels = pdata->levels;
+	ctx->nlevels = pdata->nlevels;
+
+	ctx->power = devm_regulator_get(dev->parent, "fan");
+	if (IS_ERR(ctx->power))
+		return PTR_ERR(ctx->power);
+
+	ret = regulator_enable(ctx->power);
+	if (ret) {
+		dev_err(dev, "Failed to enable fan power supply: %d\n", ret);
+		return ret;
+	}
+
 	platform_set_drvdata(pdev, ctx);
 
 	cdev = devm_thermal_of_child_cooling_device_register(dev->parent,
@@ -125,14 +144,19 @@ static int khadas_mcu_fan_suspend(struct device *dev)
 
 	ctx->level = level_save;
 
-	return 0;
+	return regulator_disable(ctx->power);
 }
 
 static int khadas_mcu_fan_resume(struct device *dev)
 {
 	struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
+	int ret;
+
+	ret = regulator_enable(ctx->power);
+	if (ret)
+		return ret;
 
-	return khadas_mcu_fan_set_level(ctx, ctx->level);
+	return khadas_mcu_fan_set_level(ctx, ctx->levels[ctx->level]);
 }
 #endif
 

-- 
2.49.0

[PATCH v9 5/6] arm64: dts: amlogic: t7: Add i2c controller node

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Add the T7 i2c controller node used by the Khadas VIM4
for MCU communication.

Use amlogic,meson-axg-i2c as fallback compatible.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
index c3dc479b137de..0f48e23077e99 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
@@ -724,6 +724,16 @@ pwm_ao_cd: pwm@60000 {
 				status = "disabled";
 			};
 
+			i2c_m_ao_a: i2c@76000 {
+				compatible = "amlogic,t7-i2c", "amlogic,meson-axg-i2c";
+				reg = <0x0 0x76000 0x0 0x48>;
+				#address-cells = <1>;
+				#size-cells = <0>;
+				interrupts = <GIC_SPI 330 IRQ_TYPE_EDGE_RISING>;
+				clocks = <&clkc_periphs CLKID_SYS_I2C_AO_A>;
+				status = "disabled";
+			};
+
 			sd_emmc_a: mmc@88000 {
 				compatible = "amlogic,t7-mmc", "amlogic,meson-axg-mmc";
 				reg = <0x0 0x88000 0x0 0x800>;

-- 
2.49.0

[PATCH v9 6/6] arm64: dts: amlogic: t7: khadas-vim4: Add i2c MCU fan node

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Enable and configure i2c MCU node to get fan working on Khadas VIM4.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 .../boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts      | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index c41525a34b721..7d95aadcf6a66 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -167,6 +167,19 @@ xtal: xtal-clk {
 	};
 };
 
+&i2c_m_ao_a {
+	status = "okay";
+	pinctrl-0 = <&i2c0_ao_d_pins>;
+	pinctrl-names = "default";
+
+	khadas_mcu: system-controller@18 {
+		compatible = "khadas,vim4-mcu";
+		reg = <0x18>;
+		fan-supply = <&vcc5v>;
+		#cooling-cells = <2>;
+	};
+};
+
 &pwm_ab {
 	status = "okay";
 	pinctrl-0 = <&pwm_a_pins>;

-- 
2.49.0

Re: [PATCH v9 4/6] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support

[Daniel Lezcano]

On 8/5/26 10:06, Ronald Claveau via B4 Relay wrote:
> From: Ronald Claveau <linux-kernel-dev@aliel.fr>
> 
> Replace the hardcoded MAX_LEVEL constant and fan register
> with values read from platform_data (fan_reg, levels[] and nlevels),
> as new MCUs need different values.
> 
> The cooling device's state is stored as an index into levels[],
> and khadas_mcu_fan_set_level() writes levels[state] to fan_reg,
> rather than writing the raw state value as before.
> 
> Optionally acquire and enable a "fan" regulator supply
> at probe time and on resume,
> so boards that gate fan power through a regulator are handled.
> 
> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
> Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
> ---

  * Through which tree this patch should go ? (assuming there is a 
dependency on other patches)

  * How this will behave with 100 levels with the step wise governor ? 
For a 100ms passive delay and 100 states, it will take 10s before 
reaching the full speed