From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

The MC33XS2410 provides temperature sensors for the central die temperature
and the four outputs. Additionally a common temperature warning threshold
can be configured for the outputs. Add hwmon support for the sensors.

Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
---
Changes in v2:
- Remove helper mc33xs2410_hwmon_read_out_status and report the last
  latched status.
- Link to v1: https://lore.kernel.org/r/20250512-mc33xs2410-hwmon-v1-1-addba77c78f9@liebherr.com
---
 drivers/pwm/Kconfig          |   1 +
 drivers/pwm/pwm-mc33xs2410.c | 164 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 164 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 6faa8b2ec0a4844f667a84335f30bde44d52378e..0deaf8447f4302e7cfd3b4cb35c7d46ef19e006c 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -425,6 +425,7 @@ config PWM_LPSS_PLATFORM
 
 config PWM_MC33XS2410
 	tristate "MC33XS2410 PWM support"
+	depends on HWMON || HWMON=n
 	depends on OF
 	depends on SPI
 	help
diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
index a1ac3445ccdb4709d92e0075d424a8abc1416eee..c1b99b1143141242ce99782162ae05536dd88163 100644
--- a/drivers/pwm/pwm-mc33xs2410.c
+++ b/drivers/pwm/pwm-mc33xs2410.c
@@ -21,6 +21,7 @@
 #include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/hwmon.h>
 #include <linux/math64.h>
 #include <linux/minmax.h>
 #include <linux/module.h>
@@ -29,6 +30,8 @@
 
 #include <linux/spi/spi.h>
 
+/* ctrl registers */
+
 #define MC33XS2410_GLB_CTRL			0x00
 #define MC33XS2410_GLB_CTRL_MODE		GENMASK(7, 6)
 #define MC33XS2410_GLB_CTRL_MODE_NORMAL		FIELD_PREP(MC33XS2410_GLB_CTRL_MODE, 1)
@@ -51,6 +54,21 @@
 
 #define MC33XS2410_WDT				0x14
 
+#define MC33XS2410_TEMP_WT			0x29
+#define MC33XS2410_TEMP_WT_MASK			GENMASK(7, 0)
+
+/* diag registers */
+
+/* chan in { 1 ... 4 } */
+#define MC33XS2410_OUT_STA(chan)		(0x02 + (chan) - 1)
+#define MC33XS2410_OUT_STA_OTW			BIT(8)
+
+#define MC33XS2410_TS_TEMP_DIE			0x26
+#define MC33XS2410_TS_TEMP_MASK			GENMASK(9, 0)
+
+/* chan in { 1 ... 4 } */
+#define MC33XS2410_TS_TEMP(chan)		(0x2f + (chan) - 1)
+
 #define MC33XS2410_PWM_MIN_PERIOD		488282
 /* step in { 0 ... 3 } */
 #define MC33XS2410_PWM_MAX_PERIOD(step)		(2000000000 >> (2 * (step)))
@@ -125,6 +143,11 @@ static int mc33xs2410_read_reg_ctrl(struct spi_device *spi, u8 reg, u16 *val)
 	return mc33xs2410_read_reg(spi, reg, val, MC33XS2410_FRAME_IN_DATA_RD);
 }
 
+static int mc33xs2410_read_reg_diag(struct spi_device *spi, u8 reg, u16 *val)
+{
+	return mc33xs2410_read_reg(spi, reg, val, 0);
+}
+
 static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val)
 {
 	u16 tmp;
@@ -140,6 +163,145 @@ static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val
 	return mc33xs2410_write_reg(spi, reg, tmp);
 }
 
+#if IS_ENABLED(CONFIG_HWMON)
+static const struct hwmon_channel_info * const mc33xs2410_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(temp,
+			   HWMON_T_LABEL | HWMON_T_INPUT,
+			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
+			   HWMON_T_ALARM,
+			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
+			   HWMON_T_ALARM,
+			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
+			   HWMON_T_ALARM,
+			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
+			   HWMON_T_ALARM),
+	NULL,
+};
+
+static umode_t mc33xs2410_hwmon_is_visible(const void *data,
+					   enum hwmon_sensor_types type,
+					   u32 attr, int channel)
+{
+	switch (attr) {
+	case hwmon_temp_input:
+	case hwmon_temp_alarm:
+	case hwmon_temp_label:
+		return 0444;
+	case hwmon_temp_max:
+		return 0644;
+	default:
+		return 0;
+	}
+}
+
+static int mc33xs2410_hwmon_read(struct device *dev,
+				 enum hwmon_sensor_types type,
+				 u32 attr, int channel, long *val)
+{
+	struct spi_device *spi = dev_get_drvdata(dev);
+	u16 reg_val;
+	int ret;
+	u8 reg;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		reg = (channel == 0) ? MC33XS2410_TS_TEMP_DIE :
+				       MC33XS2410_TS_TEMP(channel);
+		ret = mc33xs2410_read_reg_diag(spi, reg, &reg_val);
+		if (ret < 0)
+			return ret;
+
+		/* LSB is 0.25 degree celsius */
+		*val = FIELD_GET(MC33XS2410_TS_TEMP_MASK, reg_val) * 250 - 40000;
+		return 0;
+	case hwmon_temp_alarm:
+		ret = mc33xs2410_read_reg_diag(spi, MC33XS2410_OUT_STA(channel),
+					       &reg_val);
+		if (ret < 0)
+			return ret;
+
+		*val = FIELD_GET(MC33XS2410_OUT_STA_OTW, reg_val);
+		return 0;
+	case hwmon_temp_max:
+		ret = mc33xs2410_read_reg_ctrl(spi, MC33XS2410_TEMP_WT, &reg_val);
+		if (ret < 0)
+			return ret;
+
+		/* LSB is 1 degree celsius */
+		*val = FIELD_GET(MC33XS2410_TEMP_WT_MASK, reg_val) * 1000 - 40000;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int mc33xs2410_hwmon_write(struct device *dev,
+				  enum hwmon_sensor_types type, u32 attr,
+				  int channel, long val)
+{
+	struct spi_device *spi = dev_get_drvdata(dev);
+
+	switch (attr) {
+	case hwmon_temp_max:
+		val = clamp_val(val, -40000, 215000);
+
+		/* LSB is 1 degree celsius */
+		val = (val / 1000) + 40;
+		return mc33xs2410_modify_reg(spi, MC33XS2410_TEMP_WT,
+					     MC33XS2410_TEMP_WT_MASK, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const char *const mc33xs2410_temp_label[] = {
+	"Central die temperature",
+	"Channel 1 temperature",
+	"Channel 2 temperature",
+	"Channel 3 temperature",
+	"Channel 4 temperature",
+};
+
+static int mc33xs2410_read_string(struct device *dev,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel, const char **str)
+{
+	*str = mc33xs2410_temp_label[channel];
+
+	return 0;
+}
+
+static const struct hwmon_ops mc33xs2410_hwmon_hwmon_ops = {
+	.is_visible = mc33xs2410_hwmon_is_visible,
+	.read = mc33xs2410_hwmon_read,
+	.read_string = mc33xs2410_read_string,
+	.write = mc33xs2410_hwmon_write,
+};
+
+static const struct hwmon_chip_info mc33xs2410_hwmon_chip_info = {
+	.ops = &mc33xs2410_hwmon_hwmon_ops,
+	.info = mc33xs2410_hwmon_info,
+};
+
+static int mc33xs2410_hwmon_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct device *hwmon;
+
+	hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
+						     &mc33xs2410_hwmon_chip_info,
+						     NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon);
+}
+
+#else
+static int mc33xs2410_hwmon_probe(struct spi_device *spi)
+{
+	return 0;
+}
+#endif
+
 static u8 mc33xs2410_pwm_get_freq(u64 period)
 {
 	u8 step, count;
@@ -361,7 +523,7 @@ static int mc33xs2410_probe(struct spi_device *spi)
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to add pwm chip\n");
 
-	return 0;
+	return mc33xs2410_hwmon_probe(spi);
 }
 
 static const struct spi_device_id mc33xs2410_spi_id[] = {

---
base-commit: 7395eb13e3a85067de3e083d3781630ea303c0c4
change-id: 20250507-mc33xs2410-hwmon-a5ff9efec005

Best regards,
-- 
Dimitri Fedrau <dimitri.fedrau@liebherr.com>

Hello Dimitri,

On Thu, May 15, 2025 at 02:40:54PM +0200, Dimitri Fedrau via B4 Relay wrote:
> From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> 
> The MC33XS2410 provides temperature sensors for the central die temperature
> and the four outputs. Additionally a common temperature warning threshold
> can be configured for the outputs. Add hwmon support for the sensors.
> 
> Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> ---
> Changes in v2:
> - Remove helper mc33xs2410_hwmon_read_out_status and report the last
>   latched status.
> - Link to v1: https://lore.kernel.org/r/20250512-mc33xs2410-hwmon-v1-1-addba77c78f9@liebherr.com
> ---

Mostly fine from my POV. I suggest to squash the following change into
your patch:

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index a0c077af9c98..d9bcd1e8413e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -425,7 +425,6 @@ config PWM_LPSS_PLATFORM
 
 config PWM_MC33XS2410
 	tristate "MC33XS2410 PWM support"
-	depends on HWMON || HWMON=n
 	depends on OF
 	depends on SPI
 	help
diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
index c1b99b114314..f5bba1a7bcc5 100644
--- a/drivers/pwm/pwm-mc33xs2410.c
+++ b/drivers/pwm/pwm-mc33xs2410.c
@@ -163,7 +163,6 @@ static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val
 	return mc33xs2410_write_reg(spi, reg, tmp);
 }
 
-#if IS_ENABLED(CONFIG_HWMON)
 static const struct hwmon_channel_info * const mc33xs2410_hwmon_info[] = {
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_LABEL | HWMON_T_INPUT,
@@ -286,21 +285,20 @@ static const struct hwmon_chip_info mc33xs2410_hwmon_chip_info = {
 static int mc33xs2410_hwmon_probe(struct spi_device *spi)
 {
 	struct device *dev = &spi->dev;
-	struct device *hwmon;
 
-	hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
-						     &mc33xs2410_hwmon_chip_info,
-						     NULL);
+	if (IS_REACHABLE(CONFIG_HWMON)) {
+		struct device *hwmon;
 
-	return PTR_ERR_OR_ZERO(hwmon);
-}
+		hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
+							     &mc33xs2410_hwmon_chip_info,
+							     NULL);
 
-#else
-static int mc33xs2410_hwmon_probe(struct spi_device *spi)
-{
-	return 0;
+		return PTR_ERR_OR_ZERO(hwmon);
+	} else {
+		dev_dbg(dev, "Not registering hwmon sensors\n");
+		return 0;
+	}
 }
-#endif
 
 static u8 mc33xs2410_pwm_get_freq(u64 period)
 {
@@ -523,7 +521,11 @@ static int mc33xs2410_probe(struct spi_device *spi)
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to add pwm chip\n");
 
-	return mc33xs2410_hwmon_probe(spi);
+	ret = mc33xs2410_hwmon_probe(spi);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register hwmon sensors\n");
+
+	return 0;
 }
 
 static const struct spi_device_id mc33xs2410_spi_id[] = {
Best regards
Uwe

Hi Uwe,

Am Fri, May 16, 2025 at 11:24:33AM +0200 schrieb Uwe Kleine-König:
> Hello Dimitri,
> 
> On Thu, May 15, 2025 at 02:40:54PM +0200, Dimitri Fedrau via B4 Relay wrote:
> > From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> > 
> > The MC33XS2410 provides temperature sensors for the central die temperature
> > and the four outputs. Additionally a common temperature warning threshold
> > can be configured for the outputs. Add hwmon support for the sensors.
> > 
> > Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> > ---
> > Changes in v2:
> > - Remove helper mc33xs2410_hwmon_read_out_status and report the last
> >   latched status.
> > - Link to v1: https://lore.kernel.org/r/20250512-mc33xs2410-hwmon-v1-1-addba77c78f9@liebherr.com
> > ---
> 
> Mostly fine from my POV. I suggest to squash the following change into
> your patch:
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index a0c077af9c98..d9bcd1e8413e 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -425,7 +425,6 @@ config PWM_LPSS_PLATFORM
>  
>  config PWM_MC33XS2410
>  	tristate "MC33XS2410 PWM support"
> -	depends on HWMON || HWMON=n
>  	depends on OF
>  	depends on SPI
>  	help
> diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
> index c1b99b114314..f5bba1a7bcc5 100644
> --- a/drivers/pwm/pwm-mc33xs2410.c
> +++ b/drivers/pwm/pwm-mc33xs2410.c
> @@ -163,7 +163,6 @@ static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val
>  	return mc33xs2410_write_reg(spi, reg, tmp);
>  }
>  
> -#if IS_ENABLED(CONFIG_HWMON)
>  static const struct hwmon_channel_info * const mc33xs2410_hwmon_info[] = {
>  	HWMON_CHANNEL_INFO(temp,
>  			   HWMON_T_LABEL | HWMON_T_INPUT,
> @@ -286,21 +285,20 @@ static const struct hwmon_chip_info mc33xs2410_hwmon_chip_info = {
>  static int mc33xs2410_hwmon_probe(struct spi_device *spi)
>  {
>  	struct device *dev = &spi->dev;
> -	struct device *hwmon;
>  
> -	hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
> -						     &mc33xs2410_hwmon_chip_info,
> -						     NULL);
> +	if (IS_REACHABLE(CONFIG_HWMON)) {
> +		struct device *hwmon;
>  
> -	return PTR_ERR_OR_ZERO(hwmon);
> -}
> +		hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
> +							     &mc33xs2410_hwmon_chip_info,
> +							     NULL);
>  
> -#else
> -static int mc33xs2410_hwmon_probe(struct spi_device *spi)
> -{
> -	return 0;
> +		return PTR_ERR_OR_ZERO(hwmon);
> +	} else {
> +		dev_dbg(dev, "Not registering hwmon sensors\n");
> +		return 0;
> +	}
>  }
> -#endif
>  
>  static u8 mc33xs2410_pwm_get_freq(u64 period)
>  {
> @@ -523,7 +521,11 @@ static int mc33xs2410_probe(struct spi_device *spi)
>  	if (ret < 0)
>  		return dev_err_probe(dev, ret, "Failed to add pwm chip\n");
>  
> -	return mc33xs2410_hwmon_probe(spi);
> +	ret = mc33xs2410_hwmon_probe(spi);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "Failed to register hwmon sensors\n");
> +
> +	return 0;
>  }
>  
>  static const struct spi_device_id mc33xs2410_spi_id[] = {

Perfering IS_REACHABLE over IS_ENABLED is fine for me. Is there a reason
why you just didn't replace IS_ENABLED with IS_REACHABLE ?

Best regards,
Dimitri Fedrau

Hello Dimitri,

On Mon, May 19, 2025 at 02:40:28PM +0200, Dimitri Fedrau wrote:
> Perfering IS_REACHABLE over IS_ENABLED is fine for me. Is there a reason
> why you just didn't replace IS_ENABLED with IS_REACHABLE ?

Because if (IS_REACHABLE(...)) is nicer than #if IS_REACHABLE(...). It
has better compile coverage and is easier to parse for a human.

Best regards
Uwe

Am Mon, May 19, 2025 at 03:47:26PM +0200 schrieb Uwe Kleine-König:
> Hello Dimitri,
> 
> On Mon, May 19, 2025 at 02:40:28PM +0200, Dimitri Fedrau wrote:
> > Perfering IS_REACHABLE over IS_ENABLED is fine for me. Is there a reason
> > why you just didn't replace IS_ENABLED with IS_REACHABLE ?
> 
> Because if (IS_REACHABLE(...)) is nicer than #if IS_REACHABLE(...). It
> has better compile coverage and is easier to parse for a human.
> 
Sorry, my question was not precise. Diff below is about the replacement
of IS_ENABLED.

diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
index c1b99b114314..b17912ffab19 100644
--- a/drivers/pwm/pwm-mc33xs2410.c
+++ b/drivers/pwm/pwm-mc33xs2410.c
@@ -163,7 +163,7 @@ static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val
        return mc33xs2410_write_reg(spi, reg, tmp);
 }
 
-#if IS_ENABLED(CONFIG_HWMON)
+#if IS_REACHABLE(CONFIG_HWMON)
 static const struct hwmon_channel_info * const mc33xs2410_hwmon_info[] = {
        HWMON_CHANNEL_INFO(temp,
                           HWMON_T_LABEL | HWMON_T_INPUT,


Best regards,
Dimitri Fedrau

Hello,

On Mon, May 19, 2025 at 04:12:23PM +0200, Dimitri Fedrau wrote:
> Am Mon, May 19, 2025 at 03:47:26PM +0200 schrieb Uwe Kleine-König:
> > Hello Dimitri,
> > 
> > On Mon, May 19, 2025 at 02:40:28PM +0200, Dimitri Fedrau wrote:
> > > Perfering IS_REACHABLE over IS_ENABLED is fine for me. Is there a reason
> > > why you just didn't replace IS_ENABLED with IS_REACHABLE ?
> > 
> > Because if (IS_REACHABLE(...)) is nicer than #if IS_REACHABLE(...). It
> > has better compile coverage and is easier to parse for a human.
> > 
> Sorry, my question was not precise. Diff below is about the replacement
> of IS_ENABLED.

FTR: We resolved that question in a private conversation. I'm waiting
for a v3 now (but not holding my breath :-)

Best regards
Uwe

On 5/15/25 05:40, Dimitri Fedrau via B4 Relay wrote:
> From: Dimitri Fedrau <dimitri.fedrau@liebherr.com>
> 
> The MC33XS2410 provides temperature sensors for the central die temperature
> and the four outputs. Additionally a common temperature warning threshold
> can be configured for the outputs. Add hwmon support for the sensors.
> 
> Signed-off-by: Dimitri Fedrau <dimitri.fedrau@liebherr.com>

 From hwmon perspective:

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
> Changes in v2:
> - Remove helper mc33xs2410_hwmon_read_out_status and report the last
>    latched status.
> - Link to v1: https://lore.kernel.org/r/20250512-mc33xs2410-hwmon-v1-1-addba77c78f9@liebherr.com
> ---
>   drivers/pwm/Kconfig          |   1 +
>   drivers/pwm/pwm-mc33xs2410.c | 164 ++++++++++++++++++++++++++++++++++++++++++-
>   2 files changed, 164 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 6faa8b2ec0a4844f667a84335f30bde44d52378e..0deaf8447f4302e7cfd3b4cb35c7d46ef19e006c 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -425,6 +425,7 @@ config PWM_LPSS_PLATFORM
>   
>   config PWM_MC33XS2410
>   	tristate "MC33XS2410 PWM support"
> +	depends on HWMON || HWMON=n
>   	depends on OF
>   	depends on SPI
>   	help
> diff --git a/drivers/pwm/pwm-mc33xs2410.c b/drivers/pwm/pwm-mc33xs2410.c
> index a1ac3445ccdb4709d92e0075d424a8abc1416eee..c1b99b1143141242ce99782162ae05536dd88163 100644
> --- a/drivers/pwm/pwm-mc33xs2410.c
> +++ b/drivers/pwm/pwm-mc33xs2410.c
> @@ -21,6 +21,7 @@
>   #include <linux/bitfield.h>
>   #include <linux/delay.h>
>   #include <linux/err.h>
> +#include <linux/hwmon.h>
>   #include <linux/math64.h>
>   #include <linux/minmax.h>
>   #include <linux/module.h>
> @@ -29,6 +30,8 @@
>   
>   #include <linux/spi/spi.h>
>   
> +/* ctrl registers */
> +
>   #define MC33XS2410_GLB_CTRL			0x00
>   #define MC33XS2410_GLB_CTRL_MODE		GENMASK(7, 6)
>   #define MC33XS2410_GLB_CTRL_MODE_NORMAL		FIELD_PREP(MC33XS2410_GLB_CTRL_MODE, 1)
> @@ -51,6 +54,21 @@
>   
>   #define MC33XS2410_WDT				0x14
>   
> +#define MC33XS2410_TEMP_WT			0x29
> +#define MC33XS2410_TEMP_WT_MASK			GENMASK(7, 0)
> +
> +/* diag registers */
> +
> +/* chan in { 1 ... 4 } */
> +#define MC33XS2410_OUT_STA(chan)		(0x02 + (chan) - 1)
> +#define MC33XS2410_OUT_STA_OTW			BIT(8)
> +
> +#define MC33XS2410_TS_TEMP_DIE			0x26
> +#define MC33XS2410_TS_TEMP_MASK			GENMASK(9, 0)
> +
> +/* chan in { 1 ... 4 } */
> +#define MC33XS2410_TS_TEMP(chan)		(0x2f + (chan) - 1)
> +
>   #define MC33XS2410_PWM_MIN_PERIOD		488282
>   /* step in { 0 ... 3 } */
>   #define MC33XS2410_PWM_MAX_PERIOD(step)		(2000000000 >> (2 * (step)))
> @@ -125,6 +143,11 @@ static int mc33xs2410_read_reg_ctrl(struct spi_device *spi, u8 reg, u16 *val)
>   	return mc33xs2410_read_reg(spi, reg, val, MC33XS2410_FRAME_IN_DATA_RD);
>   }
>   
> +static int mc33xs2410_read_reg_diag(struct spi_device *spi, u8 reg, u16 *val)
> +{
> +	return mc33xs2410_read_reg(spi, reg, val, 0);
> +}
> +
>   static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val)
>   {
>   	u16 tmp;
> @@ -140,6 +163,145 @@ static int mc33xs2410_modify_reg(struct spi_device *spi, u8 reg, u8 mask, u8 val
>   	return mc33xs2410_write_reg(spi, reg, tmp);
>   }
>   
> +#if IS_ENABLED(CONFIG_HWMON)
> +static const struct hwmon_channel_info * const mc33xs2410_hwmon_info[] = {
> +	HWMON_CHANNEL_INFO(temp,
> +			   HWMON_T_LABEL | HWMON_T_INPUT,
> +			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
> +			   HWMON_T_ALARM,
> +			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
> +			   HWMON_T_ALARM,
> +			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
> +			   HWMON_T_ALARM,
> +			   HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX |
> +			   HWMON_T_ALARM),
> +	NULL,
> +};
> +
> +static umode_t mc33xs2410_hwmon_is_visible(const void *data,
> +					   enum hwmon_sensor_types type,
> +					   u32 attr, int channel)
> +{
> +	switch (attr) {
> +	case hwmon_temp_input:
> +	case hwmon_temp_alarm:
> +	case hwmon_temp_label:
> +		return 0444;
> +	case hwmon_temp_max:
> +		return 0644;
> +	default:
> +		return 0;
> +	}
> +}
> +
> +static int mc33xs2410_hwmon_read(struct device *dev,
> +				 enum hwmon_sensor_types type,
> +				 u32 attr, int channel, long *val)
> +{
> +	struct spi_device *spi = dev_get_drvdata(dev);
> +	u16 reg_val;
> +	int ret;
> +	u8 reg;
> +
> +	switch (attr) {
> +	case hwmon_temp_input:
> +		reg = (channel == 0) ? MC33XS2410_TS_TEMP_DIE :
> +				       MC33XS2410_TS_TEMP(channel);
> +		ret = mc33xs2410_read_reg_diag(spi, reg, &reg_val);
> +		if (ret < 0)
> +			return ret;
> +
> +		/* LSB is 0.25 degree celsius */
> +		*val = FIELD_GET(MC33XS2410_TS_TEMP_MASK, reg_val) * 250 - 40000;
> +		return 0;
> +	case hwmon_temp_alarm:
> +		ret = mc33xs2410_read_reg_diag(spi, MC33XS2410_OUT_STA(channel),
> +					       &reg_val);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = FIELD_GET(MC33XS2410_OUT_STA_OTW, reg_val);
> +		return 0;
> +	case hwmon_temp_max:
> +		ret = mc33xs2410_read_reg_ctrl(spi, MC33XS2410_TEMP_WT, &reg_val);
> +		if (ret < 0)
> +			return ret;
> +
> +		/* LSB is 1 degree celsius */
> +		*val = FIELD_GET(MC33XS2410_TEMP_WT_MASK, reg_val) * 1000 - 40000;
> +		return 0;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static int mc33xs2410_hwmon_write(struct device *dev,
> +				  enum hwmon_sensor_types type, u32 attr,
> +				  int channel, long val)
> +{
> +	struct spi_device *spi = dev_get_drvdata(dev);
> +
> +	switch (attr) {
> +	case hwmon_temp_max:
> +		val = clamp_val(val, -40000, 215000);
> +
> +		/* LSB is 1 degree celsius */
> +		val = (val / 1000) + 40;
> +		return mc33xs2410_modify_reg(spi, MC33XS2410_TEMP_WT,
> +					     MC33XS2410_TEMP_WT_MASK, val);
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +
> +static const char *const mc33xs2410_temp_label[] = {
> +	"Central die temperature",
> +	"Channel 1 temperature",
> +	"Channel 2 temperature",
> +	"Channel 3 temperature",
> +	"Channel 4 temperature",
> +};
> +
> +static int mc33xs2410_read_string(struct device *dev,
> +				  enum hwmon_sensor_types type,
> +				  u32 attr, int channel, const char **str)
> +{
> +	*str = mc33xs2410_temp_label[channel];
> +
> +	return 0;
> +}
> +
> +static const struct hwmon_ops mc33xs2410_hwmon_hwmon_ops = {
> +	.is_visible = mc33xs2410_hwmon_is_visible,
> +	.read = mc33xs2410_hwmon_read,
> +	.read_string = mc33xs2410_read_string,
> +	.write = mc33xs2410_hwmon_write,
> +};
> +
> +static const struct hwmon_chip_info mc33xs2410_hwmon_chip_info = {
> +	.ops = &mc33xs2410_hwmon_hwmon_ops,
> +	.info = mc33xs2410_hwmon_info,
> +};
> +
> +static int mc33xs2410_hwmon_probe(struct spi_device *spi)
> +{
> +	struct device *dev = &spi->dev;
> +	struct device *hwmon;
> +
> +	hwmon = devm_hwmon_device_register_with_info(dev, NULL, spi,
> +						     &mc33xs2410_hwmon_chip_info,
> +						     NULL);
> +
> +	return PTR_ERR_OR_ZERO(hwmon);
> +}
> +
> +#else
> +static int mc33xs2410_hwmon_probe(struct spi_device *spi)
> +{
> +	return 0;
> +}
> +#endif
> +
>   static u8 mc33xs2410_pwm_get_freq(u64 period)
>   {
>   	u8 step, count;
> @@ -361,7 +523,7 @@ static int mc33xs2410_probe(struct spi_device *spi)
>   	if (ret < 0)
>   		return dev_err_probe(dev, ret, "Failed to add pwm chip\n");
>   
> -	return 0;
> +	return mc33xs2410_hwmon_probe(spi);
>   }
>   
>   static const struct spi_device_id mc33xs2410_spi_id[] = {
> 
> ---
> base-commit: 7395eb13e3a85067de3e083d3781630ea303c0c4
> change-id: 20250507-mc33xs2410-hwmon-a5ff9efec005
> 
> Best regards,