[PATCH v12 4/6] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support
From: Ronald Claveau via B4 Relay
Date: Thu Sep 17 2026 - 04:02:58 EST
From: Ronald Claveau <linux-kernel-dev@xxxxxxxx>
Introduce platform name, 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).
MAX_LEVEL is kept and bumped from 3 to 5 to make
the speed change more gradual with the newer MCUs.
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.
The regulator is released via a devm_add_action_or_reset()
callback.
Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Signed-off-by: Ronald Claveau <linux-kernel-dev@xxxxxxxx>
---
drivers/thermal/khadas_mcu_fan.c | 108 +++++++++++++++++++++++++++++++--------
1 file changed, 86 insertions(+), 22 deletions(-)
diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/khadas_mcu_fan.c
index 21b3d0a71bd0d..1da639d054971 100644
--- a/drivers/thermal/khadas_mcu_fan.c
+++ b/drivers/thermal/khadas_mcu_fan.c
@@ -13,34 +13,33 @@
#include <linux/regmap.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>
+#include <linux/regulator/consumer.h>
+#include <linux/minmax.h>
-#define MAX_LEVEL 3
+#define MAX_LEVEL 5
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 = min_t(unsigned int, MAX_LEVEL, ctx->nlevels - 1);
return 0;
}
@@ -60,14 +59,21 @@ 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 > MAX_LEVEL || 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 = {
@@ -76,22 +82,71 @@ static const struct thermal_cooling_device_ops khadas_mcu_fan_cooling_ops = {
.set_cur_state = khadas_mcu_fan_set_cur_state,
};
+static void khadas_mcu_fan_regulator_disable(void *data)
+{
+ struct regulator *power = data;
+
+ regulator_disable(power);
+}
+
+static const unsigned int khadas_mcu_fan_levels[] = { 0, 1, 2, 3 };
+
+static const unsigned int khadas_mcu_vim4_fan_levels[] = { 0, 30, 40, 55, 75, 100 };
+
static int khadas_mcu_fan_probe(struct platform_device *pdev)
{
+ const struct platform_device_id *id = platform_get_device_id(pdev);
struct khadas_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
struct thermal_cooling_device *cdev;
struct device *dev = &pdev->dev;
struct khadas_mcu_fan_ctx *ctx;
int ret;
+
+ if (!dev->of_node)
+ dev->of_node = of_node_get(dev->parent->of_node);
+
+ if (!id)
+ return -EINVAL;
+
ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
+
ctx->mcu = mcu;
+ switch (id->driver_data) {
+ case KHADAS_MCU_GENERIC:
+ ctx->fan_reg = KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG;
+ ctx->levels = khadas_mcu_fan_levels;
+ ctx->nlevels = ARRAY_SIZE(khadas_mcu_fan_levels);
+ break;
+ case KHADAS_MCU_VIM4:
+ ctx->fan_reg = KHADAS_MCU_VIM4_FAN_CTRL_REG;
+ ctx->levels = khadas_mcu_vim4_fan_levels;
+ ctx->nlevels = ARRAY_SIZE(khadas_mcu_vim4_fan_levels);
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ ctx->power = devm_regulator_get(dev, "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;
+ }
+
+ ret = devm_add_action_or_reset(dev, khadas_mcu_fan_regulator_disable, ctx->power);
+ if (ret)
+ return ret;
+
platform_set_drvdata(pdev, ctx);
- cdev = devm_thermal_of_child_cooling_device_register(dev->parent,
- dev->parent->of_node,
+ cdev = devm_thermal_of_child_cooling_device_register(dev,
+ dev->of_node,
"khadas-mcu-fan", ctx,
&khadas_mcu_fan_cooling_ops);
if (IS_ERR(cdev)) {
@@ -109,21 +164,24 @@ static void khadas_mcu_fan_shutdown(struct platform_device *pdev)
{
struct khadas_mcu_fan_ctx *ctx = platform_get_drvdata(pdev);
- khadas_mcu_fan_set_level(ctx, 0);
+ khadas_mcu_fan_set_level(ctx, ctx->levels[0]);
}
#ifdef CONFIG_PM_SLEEP
static int khadas_mcu_fan_suspend(struct device *dev)
{
struct khadas_mcu_fan_ctx *ctx = dev_get_drvdata(dev);
- unsigned int level_save = ctx->level;
int ret;
- ret = khadas_mcu_fan_set_level(ctx, 0);
+ ret = khadas_mcu_fan_set_level(ctx, ctx->levels[0]);
if (ret)
return ret;
- ctx->level = level_save;
+ ret = regulator_disable(ctx->power);
+ if (ret) {
+ khadas_mcu_fan_set_level(ctx, ctx->levels[ctx->level]);
+ return ret;
+ }
return 0;
}
@@ -131,8 +189,13 @@ static int khadas_mcu_fan_suspend(struct device *dev)
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
@@ -140,7 +203,8 @@ static SIMPLE_DEV_PM_OPS(khadas_mcu_fan_pm, khadas_mcu_fan_suspend,
khadas_mcu_fan_resume);
static const struct platform_device_id khadas_mcu_fan_id_table[] = {
- { .name = "khadas-mcu-fan-ctrl", },
+ { .name = "khadas-mcu-fan-ctrl", .driver_data = KHADAS_MCU_GENERIC },
+ { .name = "khadas-mcu-vim4-fan", .driver_data = KHADAS_MCU_VIM4 },
{},
};
MODULE_DEVICE_TABLE(platform, khadas_mcu_fan_id_table);
--
2.49.0