Re: [PATCH v2 2/3] platform: arm64: lenovo-thinkpad-t14s: Wire EC thermal events to hwmon

[Ilpo Järvinen]

On Tue, 30 Jun 2026, Daniel Lezcano wrote:

> The EC generates thermal zone status change notifications for a subset
> of the exposed temperature sensors. Wire these EC events to the hwmon
> notification framework so userspace can be informed when a thermal alarm
> state changes.
> 
> Associate each hwmon temperature channel with its corresponding EC
> thermal event and emit hwmon_temp_alarm notifications through
> hwmon_notify_event() when the EC reports a thermal zone status change.
> 
> Also register thermal zones in the hwmon chip capabilities and keep a
> reference to the hwmon device to allow event propagation from the IRQ
> handler.
> 
> This allows userspace monitoring tools to receive thermal alarm
> updates without polling the sensors and gives the opportuniy to the

opportuniy -> opportunity 

> kernel to cool them down.
> 
> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxxxxxxxx>
> ---
>  drivers/platform/arm64/lenovo-thinkpad-t14s.c | 78 ++++++++++++++-----
>  1 file changed, 57 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/platform/arm64/lenovo-thinkpad-t14s.c b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
> index 35a6f8b0cb6b..5fafb01a2b33 100644
> --- a/drivers/platform/arm64/lenovo-thinkpad-t14s.c
> +++ b/drivers/platform/arm64/lenovo-thinkpad-t14s.c
> @@ -104,10 +104,13 @@ struct t14s_ec_led_classdev {
>  struct t14s_ec_hwmon_sys_thermx {
>  	const char *label;
>  	int reg;
> +	u8 event;
>  };
>  
>  struct t14s_ec_hwmon {
> +	struct device *dev;
>  	struct t14s_ec_hwmon_sys_thermx *sys_thermx;
> +	size_t num_sys_thermx;
>  };
>  
>  struct t14s_ec {
> @@ -490,6 +493,20 @@ static int t14s_input_probe(struct t14s_ec *ec)
>  	return input_register_device(ec->inputdev);
>  }
>  
> +static void t14s_ec_hwmon_notify_event(struct t14s_ec *ec, u8 event)
> +{
> +	for (int i = 0; i < ec->ec_hwmon.num_sys_thermx; i++) {
> +		if (ec->ec_hwmon.sys_thermx[i].event != event)
> +			continue;
> +
> +		hwmon_notify_event(ec->ec_hwmon.dev, hwmon_temp,
> +				   hwmon_temp_alarm, i);
> +
> +		dev_dbg(ec->dev, "Thermal Zone (%s) Status Change Event\n",
> +			ec->ec_hwmon.sys_thermx[i].label);
> +	}
> +}
> +
>  static irqreturn_t t14s_ec_irq_handler(int irq, void *data)
>  {
>  	struct t14s_ec *ec = data;
> @@ -539,13 +556,9 @@ static irqreturn_t t14s_ec_irq_handler(int irq, void *data)
>  		dev_dbg(ec->dev, "LID closed\n");
>  		break;
>  	case T14S_EC_EVT_THERMAL_TZ40:
> -		dev_dbg(ec->dev, "Thermal Zone 40 Status Change Event (CPU/GPU)\n");
> -		break;
>  	case T14S_EC_EVT_THERMAL_TZ42:
> -		dev_dbg(ec->dev, "Thermal Zone 42 Status Change Event (Battery)\n");
> -		break;
>  	case T14S_EC_EVT_THERMAL_TZ39:
> -		dev_dbg(ec->dev, "Thermal Zone 39 Status Change Event (CPU/GPU)\n");
> +		t14s_ec_hwmon_notify_event(ec, val);
>  		break;
>  	case T14S_EC_EVT_KEY_FN_G:
>  		dev_dbg(ec->dev, "FN + G - toggle double-tapping\n");
> @@ -640,13 +653,14 @@ static const struct hwmon_ops t14s_ec_hwmon_ops = {
>  };
>  
>  static const struct hwmon_channel_info *t14s_ec_hwmon_info[] = {
> +	HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
>  	HWMON_CHANNEL_INFO(temp,
> -			   HWMON_T_INPUT | HWMON_T_LABEL,
> -			   HWMON_T_INPUT | HWMON_T_LABEL,
> -			   HWMON_T_INPUT | HWMON_T_LABEL,
> -			   HWMON_T_INPUT | HWMON_T_LABEL,
> -			   HWMON_T_INPUT | HWMON_T_LABEL,
> -			   HWMON_T_INPUT | HWMON_T_LABEL),
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM,
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM,
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM,
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM,
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM,
> +			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_ALARM),
>  	NULL
>  };
>  
> @@ -657,14 +671,34 @@ static const struct hwmon_chip_info t14s_ec_chip_info = {
>  
>  static int t14s_ec_hwmon_probe(struct t14s_ec *ec)
>  {
> -	struct device *dev;
>  	struct t14s_ec_hwmon_sys_thermx sys_thermx[] = {
> -		{ .label = "soc",	.reg = T14S_EC_SYS_THERM0 },
> -		{ .label = "keyboard",	.reg = T14S_EC_SYS_THERM1 },
> -		{ .label = "base",	.reg = T14S_EC_SYS_THERM2 },
> -		{ .label = "charging",	.reg = T14S_EC_SYS_THERM3 },
> -		{ .label = "qtm",	.reg = T14S_EC_SYS_THERM6 },
> -		{ .label = "ssd",	.reg = T14S_EC_SYS_THERM7 },
> +		{
> +			.label = "soc",
> +			.reg = T14S_EC_SYS_THERM0,
> +			.event = T14S_EC_EVT_THERMAL_TZ39
> +		},
> +		{
> +			.label = "keyboard",
> +			.reg = T14S_EC_SYS_THERM1,
> +			.event = T14S_EC_EVT_THERMAL_TZ40
> +		},
> +		{
> +			.label = "base",
> +			.reg = T14S_EC_SYS_THERM2,
> +		},
> +		{
> +			.label = "charging",
> +			.reg = T14S_EC_SYS_THERM3,
> +			.event = T14S_EC_EVT_THERMAL_TZ42
> +		},
> +		{
> +			.label = "qtm",
> +			.reg = T14S_EC_SYS_THERM6
> +		},
> +		{
> +			.label = "ssd",
> +			.reg = T14S_EC_SYS_THERM7
> +		},
>  	};
>  
>  	ec->ec_hwmon.sys_thermx = devm_kmemdup_array(ec->dev, sys_thermx,
> @@ -673,10 +707,12 @@ static int t14s_ec_hwmon_probe(struct t14s_ec *ec)
>  	if (!ec->ec_hwmon.sys_thermx)
>  		return -ENOMEM;
>  
> -	dev = devm_hwmon_device_register_with_info(ec->dev, "t14s_ec", ec,
> -						   &t14s_ec_chip_info, NULL);
> +	ec->ec_hwmon.num_sys_thermx = ARRAY_SIZE(sys_thermx);

Please add include.

> +
> +	ec->ec_hwmon.dev = devm_hwmon_device_register_with_info(ec->dev, "t14s_ec", ec,
> +								&t14s_ec_chip_info, NULL);
>  
> -	return PTR_ERR_OR_ZERO(dev);
> +	return PTR_ERR_OR_ZERO(ec->ec_hwmon.dev);
>  }
>  
>  static int t14s_ec_probe(struct i2c_client *client)
> 

-- 
 i.