[PATCH v1 5/7] thermal: pmbus: add PMBus die-temp driver

[Vincent Jardin]

The driver is a thin UCLASS_THERMAL: its get_temp reads the
temperature of its parent regulator through the pmbus helper
(READ_TEMPERATURE_1), without any chip-specific code.

Signed-off-by: Vincent Jardin <vjardin at free.fr>
---

 MAINTAINERS                     |  1 +
 drivers/thermal/Kconfig         |  8 ++++++++
 drivers/thermal/Makefile        |  1 +
 drivers/thermal/pmbus_thermal.c | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 43 insertions(+)
 create mode 100644 drivers/thermal/pmbus_thermal.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 94c342036d9..258c0d9bc18 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1593,6 +1593,7 @@ F:	drivers/power/regulator/mpq8785.c
 F:	drivers/power/regulator/pmbus_generic.c
 F:	drivers/power/regulator/pmbus_helper.c
 F:	drivers/power/regulator/pmbus_helper.h
+F:	drivers/thermal/pmbus_thermal.c
 F:	include/pmbus.h
 F:	lib/pmbus.c
 
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 91c39aa4dee..30bb64ce895 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -55,4 +55,12 @@ config TI_LM74_THERMAL
 	 Enable thermal support for the Texas Instruments LM74 chip.
 	 The driver supports reading CPU temperature.
 
+config PMBUS_THERMAL
+	bool "Generic PMBus temperature"
+	depends on DM_REGULATOR_PMBUS_HELPER
+	help
+	  Expose the die-temperature reading of any PMBus voltage
+	  regulator bound by a pmbus_helper based chip driver
+	  as a UCLASS_THERMAL device.
+
 endif # if DM_THERMAL
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index b6f06c00ed9..25435f43b64 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -11,3 +11,4 @@ obj-$(CONFIG_RCAR_GEN3_THERMAL) += rcar_gen3_thermal.o
 obj-$(CONFIG_SANDBOX) += thermal_sandbox.o
 obj-$(CONFIG_TI_DRA7_THERMAL) += ti-bandgap.o
 obj-$(CONFIG_TI_LM74_THERMAL) += ti-lm74.o
+obj-$(CONFIG_PMBUS_THERMAL) += pmbus_thermal.o
diff --git a/drivers/thermal/pmbus_thermal.c b/drivers/thermal/pmbus_thermal.c
new file mode 100644
index 00000000000..c251cea8ddf
--- /dev/null
+++ b/drivers/thermal/pmbus_thermal.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2026 Free Mobile - Vincent Jardin
+ *
+ * Generic UCLASS_THERMAL companion for PMBus voltage regulators.
+ *
+ * Works with any chip bound by a pmbus_helper based regulator driver
+ * (drivers/power/regulator/<chip>.c calling
+ * pmbus_regulator_probe_common()). It auto-spawns one
+ * of these thermal devices per regulator.
+ *
+ * The reading is the chip's READ_TEMPERATURE_1 (PMBus 0x8D), decoded
+ * through the parent's pmbus_driver_info.
+ */
+
+#include <dm.h>
+#include <pmbus.h>
+#include <thermal.h>
+
+static int pmbus_thermal_get_temp(struct udevice *dev, int *temp)
+{
+	return pmbus_regulator_read_temp(dev_get_parent(dev), temp);
+}
+
+static const struct dm_thermal_ops pmbus_thermal_ops = {
+	.get_temp = pmbus_thermal_get_temp,
+};
+
+U_BOOT_DRIVER(pmbus_thermal) = {
+	.name	= "pmbus_thermal",
+	.id	= UCLASS_THERMAL,
+	.ops	= &pmbus_thermal_ops,
+};
-- 
2.43.0