Re: [PATCH 5/8] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support
From: Ronald Claveau
Date: Thu Apr 02 2026 - 13:05:32 EST
On 4/2/26 5:39 PM, Neil Armstrong wrote:
> On 4/2/26 16:27, Ronald Claveau wrote:
>> Replace the hardcoded MAX_LEVEL constant and fan register
>> with values read from platform_data (fan_reg, max_level),
>> as new MCUs need different values.
>>
>> 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.
>>
>> Signed-off-by: Ronald Claveau <linux-kernel-dev@xxxxxxxx>
>> ---
>> drivers/thermal/khadas_mcu_fan.c | 43 ++++++++++++++++++++++++++++++
>> ++++------
>> 1 file changed, 37 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/thermal/khadas_mcu_fan.c b/drivers/thermal/
>> khadas_mcu_fan.c
>> index d35e5313bea41..55b496625e3bd 100644
>> --- a/drivers/thermal/khadas_mcu_fan.c
>> +++ b/drivers/thermal/khadas_mcu_fan.c
>> @@ -13,13 +13,15 @@
>> #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;
>> + unsigned int max_level;
>> struct thermal_cooling_device *cdev;
>> + struct regulator *power;
>> };
>> static int khadas_mcu_fan_set_level(struct khadas_mcu_fan_ctx *ctx,
>> @@ -27,8 +29,7 @@ static int khadas_mcu_fan_set_level(struct
>> khadas_mcu_fan_ctx *ctx,
>> {
>> int ret;
>> - ret = regmap_write(ctx->mcu->regmap,
>> KHADAS_MCU_CMD_FAN_STATUS_CTRL_REG,
>> - level);
>> + ret = regmap_write(ctx->mcu->regmap, ctx->fan_reg, level);
>> if (ret)
>> return ret;
>> @@ -40,7 +41,9 @@ static int khadas_mcu_fan_set_level(struct
>> khadas_mcu_fan_ctx *ctx,
>> 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->max_level;
>> return 0;
>> }
>> @@ -61,7 +64,7 @@ khadas_mcu_fan_set_cur_state(struct
>> thermal_cooling_device *cdev,
>> {
>> struct khadas_mcu_fan_ctx *ctx = cdev->devdata;
>> - if (state > MAX_LEVEL)
>> + if (state > ctx->max_level)
>> return -EINVAL;
>> if (state == ctx->level)
>> @@ -83,11 +86,32 @@ static int khadas_mcu_fan_probe(struct
>> platform_device *pdev)
>> struct device *dev = &pdev->dev;
>> struct khadas_mcu_fan_ctx *ctx;
>> int ret;
>> + const struct khadas_mcu_fan_pdata *pdata =
>> dev_get_platdata(&pdev->dev);
>> ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> if (!ctx)
>> return -ENOMEM;
>> +
>> ctx->mcu = mcu;
>> + ctx->fan_reg = pdata->fan_reg;
>> + ctx->max_level = pdata->max_level;
>> +
>> + ctx->power = devm_regulator_get_optional(dev->parent, "fan");
>> + if (IS_ERR(ctx->power)) {
>> + if (PTR_ERR(ctx->power) == -ENODEV)
>> + ctx->power = NULL;
>> + else
>> + return PTR_ERR(ctx->power);
>> + }
>> +
>> + if (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_cooling_device_register(dev->parent,
>> @@ -130,6 +154,13 @@ 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;
>> +
>> + if (ctx->power) {
>> + ret = regulator_enable(ctx->power);
>
> Seems you're missing a regulator_disable() on suspend.
>
> Neil
>
You right, I will add the regulator_disable on suspend for next version.
Thanks for your feedback.
>> + if (ret)
>> + return ret;
>> + }
>> return khadas_mcu_fan_set_level(ctx, ctx->level);
>> }
>>
>
--
Best regards,
Ronald