[PATCH 5/8] thermal: khadas-mcu-fan: Add fan config from platform data Add regulator support
Neil Armstrong
neil.armstrong at linaro.org
Thu Apr 2 08:39:09 PDT 2026
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 at aliel.fr>
> ---
> 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
> + if (ret)
> + return ret;
> + }
>
> return khadas_mcu_fan_set_level(ctx, ctx->level);
> }
>
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