Re: [PATCH v4 2/2] hwmon: (lm75) Add support for Nuvoton NCT7715

From: Guenter Roeck

Date: Fri Sep 18 2026 - 11:26:22 EST


On 9/18/26 01:40, hsyemail2@xxxxxxxxx wrote:
From: Sheng-Yuan Huang <syhuang3@xxxxxxxxxxx>

The Nuvoton NCT7715 is compatible with the LM75 temperature and
limit register layout. Its 16-bit configuration register shares the
TMP112 configuration layout.

Signed-off-by: Sheng-Yuan Huang <syhuang3@xxxxxxxxxxx>


For my reference (waiting for DT patch approval):

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Thanks,
Guenter

---
v4:
- Correct NCT7715 conversion-rate initialization during probe.

v3:
- Reuse the existing TMP112 handling for NCT7715 configuration,
update intervals, and alarms.

v2:
- Use the standard SMBus word representation for the NCT7715
configuration register, removing the NCT7715-specific byte swapping
and updating its configuration masks accordingly.

Documentation/hwmon/lm75.rst | 6 ++++++
drivers/hwmon/lm75.c | 18 ++++++++++++++++++
2 files changed, 24 insertions(+)

diff --git a/Documentation/hwmon/lm75.rst b/Documentation/hwmon/lm75.rst
index ca46754e028b..fac0b8f29ddc 100644
--- a/Documentation/hwmon/lm75.rst
+++ b/Documentation/hwmon/lm75.rst
@@ -150,6 +150,12 @@ Supported chips:
https://ams.com/documents/20143/36005/AS6200_DS000449_4-00.pdf
+ * Nuvoton NCT7715
+
+ Prefix: 'nct7715'
+
+ Addresses scanned: none
+
Author: Frodo Looijaard <frodol@xxxxxx>
Description
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 2d2d752aeac9..6b482f688c9f 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -39,6 +39,7 @@ enum lm75_type { /* keep sorted in alphabetical order */
max6626,
max31725,
mcp980x,
+ nct7715,
p3t1750,
p3t1755,
pct2075,
@@ -259,6 +260,16 @@ static const struct lm75_params device_params[] = {
.sample_times = (unsigned int []){ 30, 60, 120, 240 },
.resolutions = (u8 []) {9, 10, 11, 12 },
},
+ [nct7715] = {
+ .config_reg_16bits = true,
+ .set_mask = 0x8060, /* 12-bit mode, 4 samples / second */
+ .clr_mask = 0xc080, /* no one-shot mode, clear conversion rate */
+ .default_resolution = 12,
+ .default_sample_time = 250,
+ .num_sample_times = 4,
+ .sample_times = (unsigned int []){ 125, 250, 1000, 4000 },
+ .alarm = true,
+ },
[tmp100] = {
.set_mask = 3 << 5, /* 12-bit mode */
.clr_mask = 1 << 7, /* not one-shot mode */
@@ -417,6 +428,7 @@ static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
if (attr == hwmon_temp_alarm) {
switch (data->kind) {
case as6200:
+ case nct7715:
case tmp112:
*val = !!(regval & BIT(13)) == !!(regval & BIT(2));
break;
@@ -486,6 +498,7 @@ static int lm75_update_interval(struct device *dev, long val)
if (data->params->resolutions)
data->resolution = data->params->resolutions[index];
break;
+ case nct7715:
case tmp112:
case as6200:
err = regmap_update_bits(data->regmap, LM75_REG_CONF,
@@ -848,6 +861,7 @@ static const struct i2c_device_id lm75_i2c_ids[] = {
{ .name = "max31725", .driver_data = max31725 },
{ .name = "max31726", .driver_data = max31725 },
{ .name = "mcp980x", .driver_data = mcp980x },
+ { .name = "nct7715", .driver_data = nct7715 },
{ .name = "p3t1750", .driver_data = p3t1750 },
{ .name = "p3t1755", .driver_data = p3t1755 },
{ .name = "pct2075", .driver_data = pct2075 },
@@ -972,6 +986,10 @@ static const struct of_device_id lm75_of_match[] = {
.compatible = "nxp,pct2075",
.data = (void *)pct2075
},
+ {
+ .compatible = "nuvoton,nct7715",
+ .data = (void *)nct7715
+ },
{
.compatible = "st,stds75",
.data = (void *)stds75